Masterpiece 9-Speed at Born for Brand New Luxury Vehicles CVT For

CVT for Optimised Electrification Bosch Born for Brand New Luxury Vehicles 9-SpeedMasterpiece AT KATE

Modular from the Outside” “Having No Driver Boosts “Combustion Engines are Professor Uwe Dieter Grebe, AVL Dr Johannes-Jörg Rüger, Bosch Utilisation Massively” INTERVIEWS

# December 2018 A zero-emission future is only impossible until it isn’t.

The future of mobility is electric. Most agree, but few know how to get there. Until now. With our etelligentDRIVE™ solutions, Magna is making it possible. From 48 volt and pure electric drives, to eAWD and plug-in hybrids, we’re electrifying powertrains, improving fuel efﬁ ciency, reducing the environmental impact of vehicles - and moving the industry into the future.

Science ﬁ ction thinking. Automotive reality.

Visit us at the CTI Symposium and meet our experts! www.magna.com/electriﬁ cation

MPT_Anz-eDrive_210x297_CTI_120318.indd 1 12.03.18 09:14 Dear reader, Solutions for the mobility of today Welcome to the December 2018 issue of the CTI Mag. In the automotive industry, drive diversity and drive complexity continue to shape and tomorrow. research and development activities. So once again, big-name manufacturers and suppliers report in our latest issue on numerous current developments in the field of transmissions and drives. On top of modular drives and transmissions, we also cover component-related topics such as shift elements, transmission sensors, and production and software methods. In all these fields, developers are focussing on increasing efficiency and performance while simultane- GEAR CUTTING ously reducing costs and weight. Two interviews with leading experts are complementing the above articles: Prof. Uwe Grebe, AVL, on the future and potential of combustion engines, and Dr Johannes-Jörg Rüger, Bosch, on the electrification of commercial vehicles. In the Expert Forum, the big question is what new drive functionalities we can expect from connectivity and AI between today and GEAR HONING 2035. And to round things off, our follow-up report gets you up to speed on the news from the recent CTI Symposium China. Our special thanks to everyone who helped make this new issue of CTI Mag happen. We hope you enjoy it.

Best wishes, GRINDING A zero-emission future is Your CTI Mag Team only impossible until it isn’t. TURNING

TOOLS

Science ﬁ ction thinking. Automotive reality. Michael Follmann, Exhibition & Sponsoring Director CTI Symposia, CTI Prof. Dr Ferit Küçükay, Managing Director, Institute of Automotive Engineering, Visit us at the CTI Symposium and meet our experts! www.magna.com/electriﬁ cation TU Braunschweig, Chairman CTI Symposium Sylvia Zenzinger, Conference Director CTI Symposia, CTI

www.dvs-technology.com3

MPT_Anz-eDrive_210x297_CTI_120318.indd 1 12.03.18 09:14

contents

6 Flexible Hybridisation with Added Customer Benefit Magna Powertrain

10 Efficient Electrification with the Pushbelt CVT Bosch

16 Masterpiece 9-Speed KATE R932 Automatic Transmission Born for Brand New Luxury Vehicles KATE

20 “Combustion Engines are Modular from the Outside.” Interview with Professor Uwe Dieter Grebe, Executive Vice President, AVL List

2 Electric Drive Development for a Parcel Delivery Van Punch Powertrain

26 eKontrol’s Highly Integrated Oil Cooled e-Drive System for Commercial Vehicle eKontrol

30 “Having No Driver Boosts Utilisation Massively” Interview Dr Johannes-Jörg Rüger, President Commercial Vehicles and Off-Road, Bosch

32 AVL xEV Components for Electrified Powertrains AVL

34 How will Connectivity and AI Change Future Powertrains? Expert Forum

38 Efficient Synchronizer Solutions for (Dedicated) Hybrid Transmissions Oerlikon

42 Marzocchi’s Elika Leads a “Silent” Revolution in the Automotive Sector Marzocchi

46 Maximum Particle Retention In All Dimensions Haver & Boecker

48 Torque Sensors for High Volume Production Applications Methode

52 Future-oriented Optimisation of Ring Gear Production PRAEWEMA

56 Thermal Hydrodynamic Optimisation of Grooves in a Wet Clutch BorgWarner

60 The New Building Blocks of Propulsion Systems Design Means

64 China’s Growing Expertise Impressions from the 7th CTI Symposium China ‘Automotive Drivetrains, Intelligent and Electrified’, 19 – 20 September 2018 – Shanghai, China

5 Magna cti magazine · December 2018

Flexible Hybridisation with Added Customer Benefit Electrification of conventional powertrains increases the number of possible variants and thus potential costs. However, end customers are not willing to accept these costs to fulfill legislation requirements. A modular and scalable electrification approach helps to create more flexibility and new customer value.

Dr. Carsten Bünder · Director Product Management · Magna Powertrain

How increasing diversity can be controlled Front and rear building blocks In a conventional drive, front or rear engine combined with front-, rear- There has been a trend towards front-transversal transmissions up to the and all-wheel drive principally enables six different drivetrain architec- D segment and even above. However, electric power in a hybrid configu- tures – by adding e-motors for hybridisation, diversity increases many ration is limited in usual P2 architectures due to limited available space times over. What is more, electrification will increase the bandwidth of for the EM. Magna Powertrain relies on front-transverse dual clutch applications: for example, autonomous driving will trigger less powerful, transmissions in P2.5 arrangement like the 7HDT300, Fig. 1. P2.5 enables more comfortable drives; at the same time, electrification enables “high- the EM to be connected side by side to one of the two sub-transmissions end” all-wheel drives – and so forth. Fortunately, scalable drivetrain tech- via a simple reduction gear set. The advantages of this “torque split” ar- nology based on standardised building blocks enables tailor-made solu- rangement: tions for different global requirements, e.g. with regard to CO2 emissions, locally emission-free driving, or regionally specific customer preferences. ››The reduction gear set allows for a smaller high-speed EM ››EM operation is independent from the engine crankshaft speed E-machine – the key scaling element ››EM power is variable from around 15 to 85 kW without package chang- The e-machine (EM) plays a key role in this approach. Firstly, it is the core es component for lowering CO2 emissions. Secondly, the EM turns is an en- ››Same installation length for HV and 48V hybrid drives abler for drive standardisation and scaling: the more the electric motor takes on dynamic tasks, the fewer ICE variants are required for differen- The 7HDT300 (including the base transmission 7DCT300) allows for tiation. Regarding the whole powertrain system over front and rear axle, scaling electrical power up to around 85 kW without modifying the the EM can make further contribution to reduce hardware complexity and transmission case. It can be used for P2.5 and P2.5/P4 applications, the add further benefit: “conventional” 7DCT300 can be used for P4 drive architectures.

››Scalable, application-specific CO2 reduction ››Scalable longitudinal dynamics (traction, acceleration) ›› Scalable lateral dynamics (torque vectoring) ›› Scalable all-wheel functionality ›› Scalable operation strategies through software

The prerequisite is a standardised kit of hardware like transmissions, axle components and e-drives as well as deep system expertise in terms of managing the drive components by software.

Figure 1 The high-speed e-machine in hybrid dual-clutch transmissions like the 7HDT300 can be scaled within the housing.

6 cti magazine · December 2018 Magna

Figure 2 The e-machine plays a key role in scaling future hybrid drives.

The Magna Powertrain portfolio of rear axles is based on the same scal- kW EM. Fuel consumption and longitudinal dynamics benefit to some able common parts approach. Here as well, a gear reduction enables extent. The HV architecture enables fully electric driving with higher than smaller EMs and scaling the power within the given package. Depending city speeds. on the application requirements, ASMs (no drag losses, no rare earths) or PSMs are available. P2.5/P4 HV: The highest configuration level exploits the full potential in terms of fuel consumption / CO2 as well as longitudinal and lateral Scaling CO2, performance and character dynamics. Power can be fully transformed to traction, gradeability and With increasing electric power, we expect a shift of dynamic tasks to- traction on snow are optimal. With regard to advanced traffic scenarios, wards the EM. The following examples show the potential to scale the functions like “predictive charging” and load shift charging can be used system power and powertrain characteristics, based on standardised to full effect. Permanent AWD under all SOC conditions is possible. transmission, drivetrain and EM “building blocks”, Fig. 2. The examples above show how performance and CO2 efficiency are Conventional drive: The initial configuration is a conventional front-trans- scalable using an identical ICE and a set of fixed and scalable electri- verse powertrain with 100 kW ICE, a 7DCT300 dual-clutch transmission fied transmission and drivetrain building blocks. In terms of efficiency, and 12V electrical system, intended for a C to D segment car. CO2 emis- value in use and fun-to-drive, this approach increases flexibility to design sions are around 120 g/km. Gradeability on snow is 10 percent, and lat- market and customer-oriented solutions while relying on a set of inter- eral dynamics are typical for a FWD car. changeable building blocks.

P2.5 48 V: In the first electrification step we replace the DCT by its hybrid Flexible hybridisation paths version 7HDT300 to obtain a P2.5 hybrid drive, adding 25 kW electric The 7DCT300 and 7HDT300 are intended for applications with up to power to the 100 kW ICE. This results in slightly better acceleration, and 300 Nm engine torque, the applications above matching a “mid” scaling primarily considerably reduced fuel consumption of around 16 percent. path from C to D/E and small/mid SUVs. By using a smaller DCT/HDT, Gradeability and lateral dynamics remain unchanged. further scaling paths become available.

P2.5/P4 48 V: By adding another 25 kW for the secondary e-axle, grade- A smaller DCT with 200 Nm is typically adequate for A/B vehicles, which ability on snow doubles to 20 percent, and the e-axle allows for lateral represent a large market share. The hybridised version uses the same dynamics control by longitudinal torque distribution. The front EM can scalable EM like the 7HDT300, the same actuators and power electron- act as a generator to produce electric energy, e.g. for persistent AWD ics etc. By combining it with other available standard drivetrain modules, at low SOC, or for more versatility in using load shift charging operation. the benefits of the scalable modular approach can be transferred to a lower hybridisation path, Fig. 3. “Changing lanes” by replacing just one P2.5 HV: The P2.5 high voltage hybrid relies on the same building blocks building block enables economy of scale over different vehicle segments as the 48V version. However, the transmission features an integrated 85 and mitigates the need for top-down approaches.

7 Magna cti magazine · December 2018

Figure 3 The modular scalability approach can be used in different vehicle segment paths.

Regarding small-segment applications with dominant EMs, there are even further cost reduction opportunities for DHT like solutions: For example, the EM can be used for vehicle launch and reverse driving, transmission speeds can be reduced to 5 or 4, thus reducing the number of actuation elements, etc. This is especially obvious with the advent of (partially) autonomous driving functions, and a general shift away from “performance” towards comfort and less CO2.

Figure 4 Software can change the “DNA” of the powertrain and drivetrain Software: system manager and differentiator without changing hardware components. Adding one or two propulsion sources and possibly adding a second driven axle increases complexity on the software level as well. Drivetrain- wide system competence is required to handle this, including software tools that reflect modularity and scalability. Summary One further advantage of the approach described is that drive character- Powertrain electrification is essential for meeting future CO2 goals. The istics can be modelled according to specific OEM requirements with no “right” scale of electrification very much depends on use cases and the hardware changes, Fig. 4. For example, the same building blocks enable availability/efficiency of energy sources. For a start, hybridisation means every-day-use or dynamic applications. Moreover, besides designing a on-costs through added components, and more system complexity due brand-specific “DNA” through software, different driving modes can be to many more possible architectures. Car buyers will not pay for fulfill- implemented in one vehicle, for example “Eco”, “Sport” and ”Auto”. Gen- ing legislation if they do not receive additional benefit. Fortunately, elec- erally, opportunities for differentiation rise with the amount of electrifica- trification opens potentials to scale power and customer value features tion. through the key elements e-machine and software, while creating con- siderable economy of scale via “building blocks”. This approach reduces The opportunity to scale the drive system´s behavior by software means electrification costs, speeds up the development of market-ready and af- a paradigm shift in drive development, as the OEM can define tailor- fordable hybrid drives – and opens new ways to define an OEM-specific made “features” through software instead of replacing hardware. DNA as well as attractive added value for car drivers. 

8 LEE MICROFLUIDIC COMPONENTS FOR YOUR TRANSMISSION

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LEE Hydraulische Miniaturkomponenten GmbH Am Limespark 2 · D-65843 Sulzbach · Germany Phone +49 (0) 6196/ 77369-0 [email protected] · www.lee.de THE LEE COMPANY THE LEE COMPANY Bosch cti magazine · December 2018

Efficient Electrification with the Pushbelt CVT The growing number of hybrid electric (HEV) and electric vehicles (EV) puts pressure on the market for conventional drivelines and introduces challenges but also opportunities for the automotive transmission market. The growing variety of powertrains provide an opportunity for its developers to step into new high-potential business opportunities with suitable driveline options.

Gert-Jan Van Spijk · Director Engineering Transmissions · Bosch Transmission Technology

aking use of the available asset CVT in new solutions can help powertrain developers to succeed. This Mstatement is supported by several studies presenting dedicated pushbelt CVT concepts for PHEV and EV, which will be discussed in this article. First, several topologies that integrate the variator in a hybrid driveline are discussed. The Key Performance Indicators (KPI’s) energy efficiency, system cost and performance of these simulated topologies are compared to existing hybrid topologies, showing definite benefits when using a down-sized pushbelt variator. This conclusion is supported by the results of a study that evaluates the potential of a CVT in electric vehicles through a holistic drivetrain approach. The outcome may be surprising to many, as it shows that a pushbelt variator is a valuable addition to an electric driveline in multiple ways.

Hybrid systems including CVT perform best in terms › Vehicle: small SUV (1450 KG); of efficiency, performance and costs › Powertrain reference: conventional CVT; The first study that is discussed is a comparative analysis performed on a › Optimised concept for this vehicle category (power, ratio’s, etc.); variety of powertrain topologies, with and without a pushbelt CVT, which › E-machines standardised where possible; reveals that two hybrid systems including a CVT perform best on KPI’s › 450 W auxiliary power is included in all systems. efficiency, accelerator performance and costs. The simulations were performed using dynamic programming to keep Simulations of powertrain topologies the outcome independent from the level of optimisation of the hybrid A crucial element that determines functional possibilities, performance, control strategy to the cycles. This routine determines the optimal op- energy efficiency and packaging of a hybrid system is the location of the erating condition to reach a chosen optimisation target, e.g. energy ef- electric machine (e-machine). Besides P2 and P3 systems, this study also ficiency. The outcome creates a good and neutral comparative analysis, incorporated a concept that is able to switch between P2 and P3 mode, and can be used as a relative evaluation. and a power split concept with a structure known from the Toyota Prius [3]. The line-up is completed with a CVT-based dedicated hybrid con- The previously published results are presented in a short overview in the cept (DH-CVT) proposed by Bosch Transmission Technology. next paragraph. The main results of the comparative analysis are given in Figure 1. In this study the mentioned line-up was evaluated using simulations, which allowed the researchers to set equal boundaries for the topologies as much as possible:

10 cti magazine · December 2018 Bosch

Figure 1 Benchmark results for the evaluated hybrid topologies

Promising results for P3-CVT and DH-CVT in efficiency, acceleration performance and overall system costs The main findings of this study are that CVT-based hybrid systems with a downstream e-machine topology perform best on the three KPIs: efficiency, performance and cost. The results in Figure 1 show that both P3-CVT and DH-CVT offer the overall best energy efficiency. The advantage is especially found in EV mode, which is also the most relevant for plug-in hybrid systems. The acceleration performance was evaluated on 0 – 100 km/h and 80 – 120 km/h in hybrid mode and 0 – 100 km/h in EV mode. For the upstream e-machine topologies (like P2) the total torque transfer, especially in low gear ratios, is limited by the transmission. Whereas the downstream e-machine topologies can bring all available power to the road, this results in impressive performance for P3-CVT and DH-CVT, such as significant shorter acceleration times. The system cost, including transmission, e-machine, power electronics and battery for a range of 85 km was estimated based upon benchmark data. The study concluded that dedicated designs, based on the bill of material, offered lower manufacturing cost. Reason for this is the reduction of the design to the minimal functional elements. The already discussed advantage of downstream architectures (which are dedicated designs in this study) C1 C2 P-lock Mode description regarding energy efficiency results in an increased cost advantage because of the smaller required battery capacity. These results show that 0 0 0/1 Neutral/parking the innovative DH-CVT concept proved overall best, therefore this concept was chosen by Bosch Transmission Technology to be engineered 0 1 0 Electric driving (forward & reverse) into a further stage.

What is incorporated in the DH-CVT? 1 1 0 Hybrid (Boost/charging) The core of the system as shown in Figure 2 is created by two components: one pushbelt variator and one planetary gear unit. The latter has 1 0 1 e-CVT (Charging at standstill) its sun gear connected to the ICE via the belt variator. The planet car- rier is connected to the wheels and the ring gear is connected to the e- 1 0 0 e-CVT (launching till low speeds while charging) machine. Other main components are transfer gears, a park lock and two clutches C1 and C2. This results in a system which contains a minimum number of components. Figure 2 DH-CVT concept

11 Bosch cti magazine · December 2018

Such e-machine specifications are familiar for current applications but imply large dimensions and magnetic forces to create the required torque as well as measures to enable the maximum speed. If ratio variation is added the torque to the wheels is multiplied in low gear while in high gear the high revolutions per minute are reduced. This results in a downsized e-machine specification which is visualised in Figure 3 as well. This new specification significantly reduces the size and cost of the e-motor and enables optimisation of the e-motor and invertor efficiency. Especially with the stepless CVT, the optimal efficiency is obtained by the continuous adjustments in the operating area between drive-off and Figure 3 Effect of CVT on e-motor specifications maximum speed. Figure 3 also shows the calculated impact on the characteristic and efficiency from the standard to the downsized e-motor design.

Applying CVT systems in electric vehicles Variator options for electric vehicles Currently, most passenger cars in the market with an electric driveline The difference between e-machine and combustion engine characteris- are equipped with a single-speed transmission. Multi-speed designs are tics lead to different requirements regarding a CVT in an electric drive- being studied and proposed since there is broad consensus on their per- line. The following optimisation for the CVT is applied in this study: formance benefit regarding launch and top speed range. › E-motor torque availability reduces the requirement to have high ratio Optimisation of efficiency, performance and cost on system level will fur- coverage. This reduces the size of the variator compared to conven- thermore stimulate the introduction of such transmissions, as they also tional ICE powertrains. provide opportunities for downsizing the e-machine, power electron- › The ratios at which CVT would have reduced efficiency are eliminated ics and battery. Depending on the application, the number of gears for by this smaller ratio coverage. As an effect the variator runs at higher electric drivelines is expected to increase, according to [4] even up to 4. efficiencies (Figure 4). Multi-speed transmission designs are currently proposed by a number › Due to the reduced ratio coverage, the pulley diameters are smaller and of suppliers and research institutes. A historical analogy can be found thereby have higher stiffness. This results in reduced losses because of with the number of gears for conventional drivelines. The historical and much smaller spiral running effect. expected future trend of the maximum number of speeds for ICE and › Even better efficiency will be obtained with the upcoming Bosch Single EV based passenger car drivelines seem to show similar development Loopset Belt (SLB), depicted in Figure 4, which has less internal energy and production timelines. A single speed transmission was already used loss [5]. in the first produced electric vehicle in 1884. Also first modern highway › SLB also offers higher power density, resulting in smaller overall dimen- capable EVs were and are equipped with a single speed transmission. sions of the variator [2]. › For electric vehicles, the absence of a combustion engine prioritises The start of development of multi-speed transmissions for EV is already NVH as an important aspect. This is a recognised strong KPI of the behind us. A first application is the BMW i8, although this concerns a pushbelt variator. If needed, a special design for even lower NVH is pos- plugin hybrid. During this and next year, introductions are expected in sible. several vehicle classes with China as a main market. › Reduced hydraulic requirements due to fewer actuated components (e.g. no torque converter and clutches) in combination with a reduced The benefit that a CVT can offer for electric vehicles is a trade-off ques- variator size and on-demand actuation. tion between several KPIs of the transmission and driveline such as ef- › The inertia of an electric powertrain is relative small compared to that of ficiency, performance, cost, NVH and power density. The development a conventional powertrain. Combined with the reduced inertia of the strategy of e-motors can follow different scenarios that influence the smaller variator, this has a positive effect on CVT shift dynamics. benefits of a CVT in the powertrain. An example is introduced in the next › The absence of launch and reversing elements reduces drag losses and section. actuationrequirements. › The CVT supports the e-machine in finding the most efficient condi- Electric motor optimisation tions for driveline operation. The essence of improving powertrains for electric vehicles is to apply a holistic approach for the overall system design. For example, in a sin- CVT system optimisation gle speed powertrain the e-motor has to fulfill the challenging require- As introduced in the previous section, adding ratio change functionality ments to enable both the drive off performance as well as the maximum to an electric powertrain brings new opportunities. The study presented speed. This results in a reference e-machine specification as shown in here compared four different system options. As a reference the current Figure 3. industry standard with a fixed gear (1-speed) drive to the wheels was

12 cti magazine · December 2018 Bosch

Figure 4 Improvement in variator efficiency by use of Single loopset belt (1) and reduced ratio coverage (2).

selected. The next two systems arefitted with a 2-speed gearbox, an AMT minimum requirement was defined based on what is considered to be and DCT based unit. The fourth system contains the stepless CVT. The valid for a C-segment passenger car. For the 1-speed transmission top CVT variator enables an easily obtained larger ratio coverage compared vehicle speed was not achievable due to maximum e-motor speed. All to the 2-speed gearbox for which otherwise four speeds would be re- remaining requirements were met. The acceleration performance differ- quired. ence between CVT with standard and downsized e-machine can be explained by the lower maximum power of the latter, 96 [kW] vs 111 [kW]. Benefit in energy consumption Simulations in which five different options were compared to each other Benefit in cost were part of this study. These are as explained in the previous paragraph, The use of a CVT provides two options to reduce driveline cost. Firstly, with one addition. This addition relates to the CVT system in which the the reduced energy consumption enables a reduction of battery size system optimisation, as explained in under the section Electric Motor Op- for an identical driving range. Secondly, the reduced driveline loads and timisation, was applied. The fifthoption therefore contains a CVT with a speeds provide component downsizing opportunities. Downsizing of the downsized e-motor. Combination of the 1-speed or 2-speed system with e-machine for example can be achieved by: the downsized e-motor is not possible, because the CVT with its variability and larger ratio coverage is the enabler for this optimisation. › the lower maximum speed that reduces centrifugal loads in the motor and thereby enables cheaper design solutions. Figure 5 shows these simulation results. The first apparent conclusion is › a reduction in maximum torque enables a reduced number of windings that by adding at least a 2-speed transmission the energy losses in the and copper amount, which results in smaller dimensions. Furthermore, electric system reduces significantly up to 50%. Furthermore, an overall it provides the possibility to replace rare earth materials like cobalt by system approach of a CVT with an downsized e-machine results in the cheaper magnet materials. lowest overall energy consumption . First estimations show a 10 – 21 % cost benefit between the electrical With respect to the 2-speed gearboxes the AT is competitive on energy components e-machine, inverter and battery of the standard and down- consumption which will give a torque interruption during power accel- sized CVT topology. eration, while the DCT based system leads to higher losses and additional costs. Benefit in comfort As with the conventional driveline, the variator offers best comfort with- Benefit in performance out shift shocks. For EV, where the driver does not expect shift shocks The performance of the topologies from the previous section was evalu- or fast speed transients, the NVH behavior of a CVT feels the most natu- ated by simulation. The measured KPIs are top speed, acceleration and ral. This feature will become even more important towards autonomous gradeability. The results are shown in Table 1. For each of these KPIs a driving solutions.

Simulated results Typical requirements for compact class vehicle 1-speed 2-AMT 2-DCT CVT CVT std EM std EM std EM std EM opt EM

Top speed [km/h] 170 158 >170 >170 >170 >170

Acceleration 0-100 [km/h] [s] 9.2 6.9 6.9 6.9 7.4 8.0

Table 1 Performance Gradeability [%] 35 35 35 35 35 35 simulations

13 Bosch cti magazine · December 2018

Figure 5 Energy consumption simulations

Conclusions

› CVT is a valuable solution for multiple hybrid driveline topologies. Bosch proposes a DH-CVT solution, which has a downsized topology, consisting of a planetary gear set, a pushbelt variator, spur gears and two clutches. The studies show good scores on efficiency, performance and cost. › The DH-CVT offers a robust full functional hybrid powertrain, which even in the case of a depleted battery, offers outstanding performance. › The new single loopset belt offers a good performance for conventional and electrified drivelines. The main KPIs efficiency and power density are strongly improved. › For electric vehicles, engineers of Bosch are researching the benefits of incorporating a variator into the driveline. First results are very promising. They indicate that an integral approach and further component optimisation leads to the best benefit in terms of efficiency and cost. 

References [1] Van Spijk, G., Römers, L., and Tweehuysen, M. (2018) “CVT dedicated to hybrid solutions”, paper presented at VDI Dritev congress, Bonn Germany, June 28th, 2018. [2] Van der Sluis, F., Römers, L., van Spijk, G., and Kunze, M. (2018) “A synergy between latest CVT and hybrid technology”, paper presented at the CTI USA May, 2018. [3] Taniguchi, M. (2016) “Development of new hybrid transaxle for compact-class vehicles, ” Toyota, JSAE 20165004. [4] Murphy, T. (2014) “Coming to an EV near you : Multi-speed transmissions”, Road Ahead, [www.wardsauto.com], accessed on August 3rd, 2018. [5] Van der Sluis, F., Yildiz, S., Brandsma, A., Veltmans, P., and Kunze, M. (2017) “The CVT Pushbelt reinvented for Future Compact and Efficient Powertrains”, JSAE 20175045.

14 www.drivetrain-symposium.world

www.meansindustries.com

Over the past six years, Means Industries has enjoyed a robust drive the future of automotive propulsion,” said Jeremy Holt, and highly successful relationship with the CTI Symposium. President, Means Industries. In addition to involvement with the Advisory Board, Means has taken advantage of the opportunities off ered by CTI to showcase Establishing thought-leadership within the industry is a key the latest propulsion systems and metal-forming technologies at diff erentiator that helps businesses stand out. Means has numerous Symposiums in North America, Germany and China. embraced this approach by delivering presentations on key At a recent Symposium Means introduced the fi rst-to-market propulsion systems technologies that have expanded the scope Controllable Mechanical Diode Selectable One-Way Clutch, and of possibilities for light-weighting, packaging challenges and this year in Berlin will introduce the new Dynamic Controllable system constraints to move OEMs ever closer to their targets. The Clutch. Symposium also serves as an ideal opportunity to learn from others within the industry, glean key intelligence on where the Leveraging the unique levels of interaction with visitors from future lies, and determine the most viable solutions based on the OEMs and fellow suppliers, the CTI Symposium has served a all-important voice of the customer. crucial role in helping Means develop deep and long-lasting relationships with many key customers.

“The CTI Berlin Symposium is one of the premier events for our business to engage in each year. Numerous opportunities are available for us to build knowledge, strengthen our relationships with suppliers and customers, and gain a freshened understanding of the diff erent strategies being employed to help

ABOUT MEANS Means Industries continues to develop and manufacture transformational technologies for automotive transmissions and electrifi ed propulsion systems through rigorous design and collaboration. By collectively and openly working alongside experienced OEM engineers, Means leverages unique in-house process and product design capabilities to produce award-winning innovations that improve fuel economy, reduce mass and drive performance. KATE cti magazine · December 2018

Masterpiece 9-Speed KATE R932 Automatic Transmission Born for Brand New Luxury Vehicles KATE R932, the first nine-speed planetary automatic transmission built specially without torque convertor, is making its world’s debut in a new luxury passenger vehicles under the brand AURUS.

Maxim Nagaytsev · CEO · KATE Nikolay Chernyshev · Head of engineering department · KATE

ithin the next year different types of vehicles, such as sedan AURUS SENAT, SUV AURUS KOMMENDANT Wand MPV AURUS ARSENAL (Figure 1) will be presented to wide public. All these vehicles are built on a unified hybrid modular platform with 598 hp (880 Nm) V8 engine paired with 62 hp E-motor and 9-speed automatic transmission, which transmits the torque through the transfer case to front and rear axle as all vehicles are equipped with full wheel drive systems.

16 cti magazine · December 2018 KATE

Figure 1 AURUS vehicles, equipped with KATE R932

KATE R932 (Figure 2) offers an incredible ratio spread of 8.83 for gear one to nine, which allows to reach higher driven speeds at lower engine speeds for even greater comfort. In practice this realises into being able to drive at 120 kph (75 mph) in 9th gear with an engine speed of around only 2250 rpm, for example, as well as the overall reduction in engine speed allows to get a wonderful NVH inside and outside comfort, which is mandatory for F-class vehicles.

Nowadays everyone realises his responsibility for the future of our whole planet. Sustainable Development Goals set by United Nations General Assembly help us to understand new legislative restrictions, which guide automotive industry. Fuel consumption and environmental pollution are the main drivers for KATE development of new transmissions. For this reason, KATE R932 with an extended in comparison to other trans- Figure 2: R932 layout missions ratio spread allows to keep combustion engine in its minimal fuel consumption zone as much as possible during the drive time and gives the opportunity to the whole drivetrain to be at the highest level of energy efficiency.

However, no one should forget about durability, quality and comfort, especially considering that power of modern vehicles is constantly growing. KATE R932 automatic transmission was designed to transfer peak power 630 kW and massive torque 1200 Newton meters with maximum input speed 6000 rpm. The layout of planetary gearbox, like DNA, de- fines all the design and functionality. A lot of the advantages and disadvantages can be checked during the kinematic scheme development process, such as maximum angular speed of links and deflection of sat- ellites speed, which responds to the bearing requirements and costs or maximum speed deflection in control elements, which drives the losses in friction elements. In order to create reliable products KATE LLC is using its original simulation method, developed and continuously improved for 13 years. It allows based on vehicle dynamic calculation to set up a needed gear ratios distribution and perform synthesis of planetary mechanism, following it more than 10^4..6 alternative kinematic schemes are received, which are automatically analysed based on the typical design advantages and disadvantages as well as the technological and manufac- Figure 3 KATE R932 planetary automatic transmission

17 KATE cti magazine · December 2018

turing criteria’s are taken into account. Figure 5 R932 planetary gear set location At the end of simulation just several kinematic schemes are proposed as best balanced, they are checked to be patent free and the development is also supporting main pump continued with one. Using such tool during low engine speeds and KATE engineers developed a kine- extreme temperature condi- matic scheme, which makes possi- tions. Specially installed two oil ble to realise nine forward gears and filters – the main one in the oil pan one reverse with only 4 planetary gear and a fine filter directly before the sets and 6 control elements (3 clutches valves are protecting control system and 3 brakes). KATE consider developed from all possible particles penetra- layout (Figure 2) as a best possible and tion and helping to work stable during has secured a worldwide patent for this all transmission’s life. configuration. In KATE R932, while engaging a gear, 3 control elements should be ac- In terms of the losses decrease main KATE feature, in all developed auto- tivated. (Figure 4) Friction discs with one-sided lining are used in this AT matic transmissions and, of course, in R932 (Figure 3), is the absence of to have enough thermal capacity and decreased axial dimension. More- torque converter. One of the multidisc brakes is used for launching. Such over, engineers worked hard together with friction disks supplier in order approach helps not only to get out the main losses generator of auto- to unify most of them, that’s how a “multibooster” for two clutches was matic transmissions but also to save installation space and makes the designed – 2 clutches with the same number of discs, the same springs, transmission more compact and light in comparison to the traditional AT the same pistons, located on the central shaft, provide easy and compact with torque convertor. But from the other site it increases the require- solution to feed them and to lubricate the discs with minimal drag losses ments to the hydraulic control unit and to the software necessary for due to size and location. One of the most up-to-date solutions – dog launching and gearshifting. clutch is also a part of the control elements inside the transmission. Now dog clutch is used to transfer high torque at reverse and first gear, but In order to meet these requirements and to increase control quality KATE development process for next generation is going on and the plan during the launch and at the same time reliability of electronic control is to use it as a control element instead of one multi-disc brake. This is a system, KATE implements a direct pressure control valves in R932. It is good potential for a further overall transmission efficiency increase. widely known by its efficient use of the hydraulic power and small leak- ages, which is quite necessary due to high main line pressure – up to 20 The software necessary for all control processes was specially developed bars. Such pressure guarantees extremely high (up to 1200 N*m) torque for this state of art automatic transmission “from scratch” in deep coop- transfer and quick and more efficient shifting. The actuating hydraulic eration with the vehicle manufacturer. Apart from data collected in the control unit is perfectly designed and combines 11 hydraulic valves and transmission itself (e.g. from 2 speed sensors, 4 pressure sensors), the 8 electro-magnets in two casted valve bodies. This fresh “brain” of R932 control system receives information from the engine control unit (e.g. automatic transmission feeds from main mechanical oil pump and auxiliary electric oil pump, used to support start-stop operation and all hybrid needs when engine is off. Such a combination helped to optimise the main pump and decrease its losses, as auxiliary electric oil pump

Gear C1 B2 C3 B4 B5 C6 DC Ratio Step

I 5,850     1,938 II    3,019 1,483 III    2,035 1,347 IV    1,511 1,253 V    1,206 1,206 VI    1,000 1,171 VII    0,854 1,143 VIII    0,747 1,128 IX    0,662 R     – 5,694 –

Figure 4 Shift pattern and ratio steps Figure 6 “Multibooster”

18 cti magazine · December 2018 KATE

Rear final drive Transfer box ICE KATE R932 AT E-motor

Rear drive shaft Rear propeller shaft Wheel

Front final drive

Figure 7 AURUS hybrid transmission layout

Figure 8 AURUS vehicles E-motor and high voltage architecture

engine torque, engine speed, accelerator position), the dynamic and the The other engineers subject of pride is that R932 is a part of a hybrid safety control units (e.g. steering angle, data from ABS, ESP and active transmission. KATE 9-speed automatic planetary gearbox is designed to cruise control), and is able to control launch and all shift processes op- fit P1 topology of hybrid vehicle. Such a solution is already serial and ap- timally using these data. Transmission software ensures a possibility for plied in unified modular platform on all vehicles (Figure 7). A permanent a quick skip of several gears while accelerating or decelerating – neces- magnet synchronous E-motor with a liquid cooling system is installed sary feature for multi-speed AT. Individual control strategy depending between engine and gearbox (Figure 8) and is used as a starter, gen- on the traffic situation or the driver’s preferences can be applied using erator and can add additional power (up to 46 kW) and torque (up to three transmission modes of the software: economical mode for a very 400 N*m) to the engine while acceleration. During 9-speed automatic economical driving style: early upshifts to keep engine speeds as much transmission development it was important that smooth shifting is pro- closer to minimal fuel consumption curve as possible. In sport or manual vided not only by calibration of gearbox and engine functioning, but also modes higher revving in the gears is stimulated along with the response with the help of electric machine, which has very fast torque and speed and shift times are shortened to support a sporty driving style. The TCU response to TCU commands. hardware development was also a task, which was successfully solved together with Russian supplier, who is now a serial manufacturer of it. KATE R932 can be paired with rear-wheel drive, all-wheel drive, hybrid drive and plug-in hybrid drive configurations. Start/Stop is also a pos- It should be highlighted that KATE development engineers focused a lot sible option. Suitable engines for the brand new 9-speed are 4, 6, 8, 12/ on a task of “compact modular construction” and “lightweight design”. in-line and V engines. Grinded hardened planetary gears, designed to transfer the power with high efficiency and low noise, are developed in minimal possible dimen- Serial production of this modern transmission will start in Russia in the sions. As it can be seen from layout (Figure 2 and 5), two pairs of gear first part of 2019 and the total volume for a first step will be 5000 AT’s/ sets can be arranged in two halves. This feature found the reflection in year in order to cover the whole production program for AURUS vehicles. housing design that consists of 2 lightweight aluminum parts, where the gear set pairs are located. Also, the main shaft is divided into two parts: KATE R932 9-speed automatic transmission is going to become a mile- the input shaft and central shaft, each part has channels to lubricate stone for automotive industry all over the world as a most powerful serial parts in its half. Such solution simplifies parts manufacturing, final as- planetary transmission with a lot of design innovations.  sembly of the gearbox and in addition to that gives a great opportunity to modify one of the parts within the requirements of different customers or tasks, without changing the other part – which is a best approach Figure 6 “Multibooster” for modular design.

19 Interview cti magazine · December 2018

“Combustion Engines are Modular from the Outside.” Hybrid drives need efficient architectures to keep overall s ystem costs low. In transmissions, stronger electrification enables measures like reducing the number of gears – do combustion engines have similar potential? An interview with Professor Uwe Dieter Grebe, Executive Vice President, AVL List.

As electrification levels grow, e-motors are taking So combustion engines in hybrid drives won’t load off combustion engines. To what extent can necessarily be less complex? that simplify engines? You do not need to change that much in the engine itself. There is a The more dominant the e-motor is, the more you can shift the combus- fundamental difference here between combustion engines and transmis- tion engine’s job to covering base load. For dynamic loads you use the e- sions. Combustion engines are built in a way, where the basic architec- motor; the combustion engine just follows. So you can simplify the vari- ture – the cylinder head, cylinder blocks, pistons etcetera – hardly needs able valve control system, for example, or even leave it out for stationary to be altered. You build variability on to that core from the outside – for operation. The same may apply for charging. But when you take other example different valve trains and charging systems. These external parameters into account, it might still allow to give a higher technology modules influence performance, consumption, and costs. With trans- level for combustion engines. If you want a compact engine, for example, missions, it is in a way the opposite: the real innovations are inside the it still makes sense to have at least a simple charging device. With hybrid internal architectural configuration. Actually, we have had standardised drives, other factors come into play. For example, variable valve timing combustion engines for a long time; they are modular from the outside can help reduce warm-up times. Let’s say your combustion engine cuts so to speak. Lots of manufacturers now build different variants, even in on the highway and you need to warm up the exhaust line quickly. on the same production line. They can even vary casting materials and On serial and powersplit hybrids, where you can set engine speed and cylinder bore diameters, because the lines are CNC-controlled. We can load, and thereby run a warm-up program. In the same way, variable already produce small volumes on the same lines without too much ef- turbochargers let you balance temperatures in close-coupled treatment fort. Therefore, we don’t really have problems with variant diversity like systems – or reduce the system temperature under heavy load. transmissions do.

Toyota uses a naturally aspirated Atkinson How can combustion engines help make hybrid Cycle engine for its hybrids, with no charging. drives more efficient? How useful would you say Miller or Atkinson is? You always have to look at the overall system. Let’s say you configure a I would definitely use a Miller or Atkinson cycle. The advantage is that plug-in hybrid with an electric range of 50 km. Assuming battery costs the power stroke runs with an extended expansion ratio. That takes more come down to EUR 130 or 100 per kWh, your product costs for battery, energy out of the gas in the engine cycle, and boosts thermal efficiency. e-motor and power electronics alone will be at least two to three thou- Volumetric efficiency is lower at lower rpm, but the e-motor compen- sand euro. On the other hand, if a cam phaser that costs slightly more sates for that. You do not necessarily need variable valve timing. In prin- than 12 or 13 EUR reduces consumption, you can make the hybrid drive ciple, you could set the Miller or Atkinson combustion engine to fixed more efficient and maybe make the battery a little smaller. Overall, bat- timing when dynamic requirements on the combustion engine are low. teries have the biggest potential for cutting costs. It always pays to make However, as I said, you might want variability due to other factors. combustion engines as frugal as you can, if they are not just an emer-

20 Professor Uwe Dieter Grebe during his plenary speech “the role of the drivetrain in future mobility” on the 12th CTI Symposium USA

“It always pays to make combustion engines as frugal as you can. You gain more for the gency generator, to exaggerate somewhat. You gain more for the overall overall system than you invest in the engine” system than you invest in the engine.

Which parameters have the most effect in combustion engines? e-axle at the back. Now obviously that is not going to run at highway On the one hand, it is the injection system, the charger, the valve train speeds in pure electric mode. In fact, drivability is already quite good and, looking ahead, variable compression. Variable compression has a up to 50 km/h – enough for inner cities – and we still have headroom. fair amount of potential because it lets you vary geometric compres- So we are getting emission-free driving in town, keeping battery costs sion. That complements the Miller cycle, which benefits from high basic down … while still using the combustion engine’s efficiency benefits on compression. However, you have to consider the ancillary units too. If longer journeys. you are recuperating high levels of braking energy, for example, you can fit an on-demand electric water pump instead of a mechanical pump. Ten years from now, how different will combustion Then you will not have to draw mechanical energy from the combustion engines be? engine you´ve worked so hard for to be efficient. But if the motor mostly In terms of cylinder counts and displacement, the number of basic ar- runs in stationary operation, a mechanical pump is quite efficient. You chitectures per manufacturer will keep going down. In addition, many always have to weigh things up holistically. Often, reducing inner losses manufacturers already have common basic architectures for their gaso- is better than using energy for electric propulsion. At AVL we call that line and diesel engines. There will be fewer differences and, as I said, vari- ‘attribute engineering’. As I see it, you always have to examine energy ability will be added from the outside. At AVL, we are now getting up flows carefully throughout the vehicle – not just optimise sub-systems to 200 kW/l on test engines by adding bi-turbo charging, compressors in isolation. and e-chargers in Miller cycle operation. Today, you can configure a basic engine for extremely transient applications in conventional drives by fit- So if I understand you correctly, combustion ting advanced charging, cam phasers or even variable compression. And engines can make a big contribution to efficiency, by changing the peripherals, you can adapt the same engine for less dy- even on plug-in applications? namic or even stationary operation in electrified drives. So coming back That is exactly why we have a program at AVL where we apply plug- to your original question: In some cases, the external modularity of com- in hybrids from the other end of the voltage scale so to speak. These bustion engines may allow for less complexity. But above all, external 48V systems are cheaper than high-voltage systems because they do modularity is a flexible and relatively cost-effective lever for configuring not need contact protection, unlike systems of 60V or higher. We are the whole drive system efficiently. using 48V axles with one or two e-motors. For example, we built a drive system based on a VW Golf with a motor-generator at the front, and an Interview: Gernot Goppelt

21 Punch Powertrain cti magazine · December 2018

Electric Drive Development for a Parcel Delivery Van

Joris Bronckaers · Product Architect · Punch Powertrain Alex Serrarens · Manager Business Development · Punch Powertrain

short time. Next to this benefit, electric vehicles require less maintenance cost, thanks to their limited number of rotating and moving parts. Even though the cumulated usage of these vehicles is vast, the driving range on a day to day basis is not excessively high, which limits the cost of the required battery pack. Only a limited part of the fleet would need a larger battery pack for regional delivery duty.

On top of all these operational benefits, electric delivery vans are quiet and emission free, which complies extremely well with the upswing of zero emission and/or diesel-banned city zones in which they have to operate.

Electric Powertrain Solution Punch Powertrain has developed a new dedicated electric drive for delivery vans up to 4200 kg GVW. These vehicles have a maximum speed of Application Vehicle: the StreetScooter WORK XL 90 km/h and must enable a drive-off from standstill at 20 % uphill grade, GVW and at least 0.5 m/s2 acceleration. Furthermore, because of the ex- Introduction tremely high amount of full park stops for door deliveries, the usage of Today electric drives find their application in almost all parts of mobil- the transmission park mechanism is far more intense than in any other ity, transport and utility. In case of passenger cars, the main reason to application. In this article we describe the results of this development develop EVs is to comply with NEV mandate targets (e.g. China) or CO2 process in more detail as well as the final product and implementation standards (e.g. Europe). In addition, EVs provide car makers with fur- in the target application for the StreetScooter WORK XL. StreetScooter ther differentiation instruments within their product portfolio in the ever GmbH is a 100 % subsidiary of German DHL. more competitive automotive market. However, their purchase price, range and charging times are not on par with those of ICE or (mild) hy- Powertrain sizing brid vehicles yet. For the commercial vehicle segment the main reason Torque and power output to go for EVs is to help fleet-owners achieving an improved Total Cost of The most important requirements for the (electric) delivery van are its Operation (TCO). top speed and gradeability, see Table 1.

An immediate positive TCO can be found in city and regional delivery Item Target Associated standard or additional information

services, using electric light commercial vehicles (vans). The main rea- Top speed in EV According to EN 1821-2 90 km/h son for this positive TCO is that delivery vans run almost 300 days per mode test mass payload, over a distance of 1 km year (6 days of operation per week) at 100km (city deliveries) to 300 Maximum hill 20 % According to EN 1821-2, maximum payload km (regional deliveries) of daily range. If such intense utilisation is fueled performance by low electricity charging cost, which fleet-owners can usually negoti- ate, the higher purchase price of the vehicle can be earned back in a Table 1 Top speed and hill performance requirements

22 cti magazine · December 2018 Punch Powertrain

EP1-C: Electric Propulsion System for These high level requirements were further augmented by: light commercial vehicles › A requirement to drive up to 70 km/h constant on a 4 % slope › A requirement to accelerate to top speed 90 km/h within 25 s from standstill at fully loaded condition

A sizing exercise was performed, resulting in following two stage single speed reduction gear ratio is designed to 16:1 in order to requirements: accommodate these main requirements. Notably, it can reach 4400 Nm › Maximum output torque: 4200 Nm @ 0 km/h wheel torque from standstill. The overall performance map can be re- › Maximum output power: 90 kW for at least 30 sec viewed in Figure 1. › Continuous output power: 50 kW for at least 30 min Parklock Driving 90 km/h would require around 32 kW of continuous power at the The application also requires a very durable parklock system, enabling driven wheels. ‘stop and lock’ actions to be executed at the click of an interior button. This requirement implies the need for a park-by-wire system. A further To fit these requirements Punch Powertrain choose to design a dedicated requirement is that the parklock is designed to safely engage and hold transmission drive, mated to a passenger car electric motor. The motor the vehicle on slopes up to 30 %, covering situations where – uncon- outputs 275 Nm and has 90 kW peak and 45 kW continuous power. The sciously – the vehicle is placed on slopes above 20 %.

Figure 1 Acceleration performance

23 Punch Powertrain cti magazine · December 2018

Detail cross-section EP1-C gearbox

Powertrain design Geartrain topology A ratio of 16:1 is achieved through a two-stage reduction. Other topologies were assessed but did not bring advantages in terms of packaging, cost and time-to-market.

Considering the application, it was decided to use tapered roller bearings on both intermediate shaft and output crown wheel. Targeting ball or roller bearings on the intermediate shaft would cause the packaging targets to be missed, while also adding significant weight to the transmission. The resulting design exhibits solid safety factors and features a micro-geometry below 0.5 μm over the full input torque range.

Passive lubrication A system relying on splash lubrication faces certain churning losses, which represent a significant part of the losses in all types of transmissions. These losses are minimised by an oil capture cavity, casted into the upper side of the transmission casing. The crown wheel picks up oil from the sump, which splashes off into this reservoir. The benefit is two-fold:

› A reduction of oil volume in the sump, thus reducing churning losses. › Targeted and controlled lubrication flow towards the bearings.

Further guiding of the oil flow through the transmission is the introduction of a baffle plate between the intermediate wheel and crown wheel. Because of the higher speed of the intermediate shaft, it starts evacuat- ing oil already at low speed. This oil flows directly towards the differential, artificially rising the oil level near the crown wheel. As the rerouted oil is picked-up, this allows a further reduction of sump oil level, even when the vehicle experiences inclined driving.

A magnetic oil plug is used to capture metallic wear particles.

The resulting design provides robust and efficient lubrication, without compromising the packaging.

Series production The requested time-to-market made for a challenging task. From the very start of the project, final stakeholders had to be involved to ensure design for manufacturing. Short communication lines were established between the design team, customer and suppliers, so that the design freeze would be manufacturable from hard tools. A low-to-mid volume production line was developed during the design phase and is being commissioned for SOP.  Tapered roller bearings for downstream shafts

24 25 eKontrol cti magazine · December 2018 eKontrol’s Highly Integrated Oil Cooled e-Drive System for Commercial Vehicle

Jiantao Geng · Manager of e-Drive transmission products · eKontrol

Abstract Introduction Accompany with the increasing severe global oil shortage and air pol- The eKontrol integrated oil-cooled e-drive unit can be applied in two lution, new energy vehicles are receiving more and more attention. Cur- platforms, one is for 4.5-ton logistic vehicles compatible with 3.5-ton and rently China has become the world’s largest market of new energy vehi- 2.5-ton logistics vehicles with the maximum output torque 980Nm and cles. eKontrol is dedicated to develop and provide service of power train output power 100 kw. The other is used for 12-meter buses compatible system for new energy commercial vehicle. This paper focuses on eKon- with 10~11-meter buses with the maximum output torque up to 2800 Nm trol’s second generation of e-drive system, namely integrated oil-cooled and output power 160 kw. Due to the combination of oil-cooled motor e-drive power train unit, which is designed especially for pure electric and gearbox, the structure highlights the structural integration and inte- commercial vehicles. The main characteristic of this product is the integration of cooling system, as shown in Figure 1. grated oil cooling design of electric motor with the gearbox, aiming to improve the power density and efficiency, and achieve better dynamic See the Figure 2 for the appearance. performance, together with better economy and road adaptability.

Figure 1 Integrated oil-cooled eDrive assembly Figure 2 External view of integrated oil-cooled eDrive module

26 cti magazine · December 2018 eKontrol

This product is for pure electric commercial vehicles. The combination of e-motor and gearbox and the integration of rotor shaft with the input shaft of the gearbox would realise speed reduction and torque improvement as well as the electric motor and gearbox integration.

Development Goals eKontrol developed this kind of highly integrated e-drive unit. The peak power density of the motor can reach to 2 kw/kg, increased by more than 30% compared with the water-cooled motor of the same specification, and the peak torque output capability is increased by more than 25 %.

Oil-Cooled Technology of the e-Motor For the water-cooled motor, it’s generally designed a water jacket on the housing, motor cooling through the heat exchange between the cooling water and the housing. Theories and experiences indicated that the heat source of the motor is mostly from the motor end windings position. For the water-cooled structure, this position of the heat cannot be exchanged well with the cooling water. However, the oil-cooled mo- Figure 5 Diagram of integrated oil cooling system

tor shares ATF oil with the gearbox and the oil circuit is integrated as a whole. By oil cooling, oil can be Directly sprayed to the three-phase windings, and it would improve the heat dissipation efficiency. The oil circuit is shown in Figure 3.

Figure 4 is the simulation of internal temperature distribution of the e-motor. The results show that the temperature of the end windings is significantly reduced through spraying cooling.

Integrated Design of High-speed Gear Driven When the power consumption and heat generation of the e-motor is de- termined, the integrated design of the cooling system with the gearbox is Figure 3 Oil circuit layout of the motor performed. The motor adopt a spray-type cooling and the bearings also lubricated by oil actively. The eKontrol oil-cooled e-drive system adopts a high-speed e-motor with the speed up to 13,000 rpm. In the field of commercial vehicle, due to the heavy load, as for the gearbox, such a high rotational speed is a challenge for the design and selection of the oil seal. With the integrated design, the rotor shaft of the motor and the input shaft of the gearbox are integrated, and the number of the bearing is reduced to two compared with the conventional split structure. A branch oil circuit is provided in the bearing chamber to realise the active lubrication, which ensures the cooling and lubrication effect of the bearing when the motor is at high speed. In addition, the integrated cooling no longer needs to consider the sealing safety when the motor shaft ro- tates at high speed.

The pressure and temperature of the system is monitored in different positions. The cooling medium is the universal ATF oil for the gearbox. Figure 4 Motor temperature field simulation The diagram of the integrated oil cooling system is shown in Figure 5.

27 eKontrol cti magazine · December 2018

Figure 6 Torque/power and efficiency simulation MAP

Oil flow distribution is critical to the integrated oil cooling system. There- To verify the accuracy of design and simulation results of the hydraulic fore, the selection of the diameter of each cooling oil hole is very impor- system, eKontrol developed a dedicated flow distribution test bench to tant. Based on the calculation of heat dissipation requirements of the verify whether the flow distribution of each cooling point under different e-motor, the eKontrol R&D team obtained different flow requirements of flows satisfy the design specification, thereby optimising the design and different cooling points, and then through the Amesim software, simu- finally improving cooling performance. lated bore diameters of cooling points corresponding to different flow requirements. On the other hand, in order to prevent the internal pres- You can see the power, torque and efficiency simulation maps of the in- sure of the cooling lubrication system from being excessive, a safety re- tegrated oil-cooled drive system as Figure 6. Compared to water-cooled lief valve is set on the oil pump. motor, oil-cooled e-motor has wider high efficiency area, and more stronger regarding to power&torque performance.

Conclusion and Future Development This paper discusses the development of an integrated oil-cooled pure electric drive system. In the next few years in China, with the growing of the Internet e-commerce and the industry of the express delivery, there will be a strong growth in the logistic vehicles. Most of these models are operated in cities, thus the electrification will be an inevitable trend of development. Moreover, the terrain varies greatly in different regions of China. There are many hills and slopes in the southwestern region. The integrated oil-cooled pure electric drive system can meet this kind of working condition because it is equipped with a gearbox.

In the new energy automotive field including passenger cars, e-motors and gearboxes are developing towards integration. How to speed up the e-motor and further increase the power density of the system is a key topic to the entire industry. eKontrol is also devoted to this research, fo- cusing on improving the technical level of the power train unit of the new energy commercial vehicle.

eKontrol’s Integrated oil-cooled e-Drive system has completed the development of A prototype, and it is expected that a small batch can be Figure 7 Flow distribution test onboard in early 2019. 

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30419_Edison_1804_Packshot_JETZT_210x297_CTI-Magazin_ISOc.indd 1 22.10.18 15:16 Interview cti magazine · December 2018

“Having No Driver Boosts Utilisation Massively” Powertrain electrification is progressing in commercial transport too, but requirements can differ significantly from those of passenger cars. We talked to Dr Johannes-Jörg Rüger, President Commercial Vehicles and Off-Road at Bosch, about what the future holds in store.

Dr Rüger, you expect commercial transport volumes not people. Having no driver boosts utilisation massively, because jour- to rise by around 40 percent in the next 15 years. ney times are no longer dictated by rest periods. Secondly, it makes plan- How reliable are forecasts like that? ning far easier. Logistics companies often tell us they can’t get drivers, Previous forecasts like the Shell Study have proved to be very reliable. or have to replace them at short notice. That increases complexity and One reason for the strong growth in transport volumes is that globally, costs. There is a concern that autonomous trucks could destroy jobs, but we are ordering more and more goods online. That affects both long- actually many new jobs will be created in distribution. So you could say it haul and distribution traffic. The all-important question is, how do we is a win-win-win situation – for companies, drivers, and society. deal with that? Would rail be an alternative, for instance? North America doesn’t have the infrastructure, and even in Europe rail freight capacity is What are the key business case factors for feeling the strain. We will also need to ask how roads can cope with the logistics companies? growth in commercial transport. These challenges are real – unless we Ultimately, it boils down to costs and reliability. Every new drive technol- change our consumer habits fundamentally. ogy has to match diesel engines in terms of range, maintenance, refuel- ling times etc. If I can refuel my diesel in ten minutes, charging times of five hours or more are not really an alternative. And the weight of a battery-electric long haul truck is counterproductive too. Finally, alternative drive lifecycles will need to compare with what we have now; in the US, for instance, trucks typically cover a million kilometers over seven “There is a concern that autonomous trucks or eight years. The biggest cost factors are the fuel and the driver. The could destroy jobs, but actually many new driver alone accounts for around 37 percent, fuel for about one-third. So jobs will be created in distribution” for the business case, it is all about total costs.

How much fuel can automation save? We already know that Automatic Cruise Control, for example, really does have a positive effect above a certain level of market penetration. We How can automation make transport more efficient? also know that platooning saves around ten percent for the trailing ve- Driver assistance systems help to increase safety, reduce fuel consump- hicles. The leader saves a little too, because the platoon as a whole is tion and improve traffic flows. Longer term, full automation is the most more streamlined. So with a platoon of three or four trucks, the average interesting option for two reasons. Firstly, it takes the driver out of the saving per vehicle is eight percent. Of course, nobody wants to lead a cost equation – unlike passenger cars you only want to transport goods, platoon! So we would need to think about how we divide the ‘profits’ up.

30 Johannes-Jörg Rüger during his speech on the 12th CTI Symposium USA: “The commercial vehicle of the future – electrified and automated?”

“If you have a 40-tonne truck and a quarter of ten critical in these vehicles. You want to fit as much battery as you can that weight is the battery, it does not add up” into the chassis, for instance, so the battery has to be as small as possible. Low-floor buses, for example, are incredibly limited in terms of space.

What do you think of hybrid drives for commercial Looking ahead to autonomous driving, will that vehicles? always require drive electrification? Plug-in hybrid can be interesting, for instance when the last mile needs to Strictly speaking, no. Some of our customers are planning to use combus- be electric. But then the question is: do I want a vehicle that does both – or tion engines so they won’t have to add too much complexity at once. But do we build a kind of hybrid transport system instead, with hubs where obviously driverless vehicles have to be configured for redundancy. If your we transfer goods to electric vehicles for local distribution? I think in many engine fails, you are immobilised. But if your truck has multiple electric cases, the latter solution is better. On the other hand, not all transporta- motors and one fails, you still have limited operability. But I think it is fairly tion is handled by major logistics companies that can afford dual fleets. unlikely you would fit two of everything, including the battery. Costs are a Smaller businesses will still be around as well – and for them, hybrid drives strong driver for the industry, so that is rather not going to happen. could work.

In terms of energy costs, electric vehicles compare Which drive technology makes sense for long- quite well … distance haulage? That’s true, the efficiency is good. But it won’t really work for long haul, Based on what we know today, battery electric drives are not an option. because the batteries are far more expensive and too heavy. We are In the mid to long term, I think gas combustion engines make sense until talking double-figure tonnages here. If you have a 40-tonne truck and a we have affordable alternatives. Gas is not completely emission-free, but quarter of that weight is the battery, it does not add up. at least it is a big step into the right direction. To cut fleet consumption figures in line with EU requirements we’ll also need evolutionary mea- Apart from range, what are the main challenges sures, meaning optimised diesel engines. But long term, if we effectively for electrified drivetrains? want to eliminate CO2 completely, we would need to find a way of pro- You have to make a distinction. Distribution transport vehicles will reflect ducing CO2-neutral fuel. We believe fuel cell is interesting too, but it is many of today’s developments in passenger cars. We are seeing a trend still a long shot; we have started activities in that field in the US and towards e-axles, and the synergy effects we have between passenger cars China. Generally speaking, we are keeping several options open, because and light commercial vehicles will continue. For heavier commercial ve- at the end of the day, one key question will be the total cost balance from hicles, the trend is less clear, because we do not really have series produc- the operator’s point of view. tion applications yet. But I expect we will need multiple motors to amass enough power, and to spread the package for optimal use. Package is of- Interview: Gernot Goppelt

31 AVL cti magazine · December 2018

AVL xEV Components for Electrified Powertrains

Dr. Thomas Frey · Head of Product Line E-Drive / Innovation Management · AVL Software and Functions

ero-emission mobility will be more and more important in Zthe future. The automotive industry is focused on entering into the fast-growing market of electrified powertrains for every kind of vehicle application. However, there are significant challenges for electrified vehicles in fulfilling -cus tomer needs such as high vehicle range and fast recharging time to effortlessly reach every destination. In addition, car makers currently face the following issues:

›› Which technologies enable higher powertrain efficiencies and vehicle range with consideration of manufacturing aspects and cost? ›› How can recharging time be reduced to make EV’s more attractive and comfortable?

AVL is the perfect partner to handle these challenges.

AVL’s daily business is to provide a large range of development and engineering services for e-drive components. Our focus is to develop and optimise electronic components to make them light weight, compact and highly efficient for every vehicle application. Efficiency is the most important parameter for all powertrain components to minimise losses and to enable more effective recuperation to achieve an extended range. An- other important approach to enhance performance is to research and develop improved e-motor technologies. Current trends include high-speed machines with 20,000 rpm or more and multi-phase applications to handle higher power and currents. Figure 1 New motor winding technologies (e.g. hairpin) or the usage of less rare earth materials can help to reach the Detailed simulation expertise is key required cost targets. The aim is on the one hand to reduce manufacturing costs and on the other hand to to find optimal solutions increase the power density which again enbables smaller, more compact machines with less weight. To reach these goals, newest motor cooling approaches (e.g. direct oil cooling) are applied. The cooling technology has a major impact on the e-drive system’s efficiency and the component design. Due to an improved thermal design, losses are reduced.

32 cti magazine · December 2018 AVL

Figure 2 Integrated e-axle to boost efficiency and cut cost

Latest semiconductor technologies such as SiC or GaN in power electronics (e.g. inverter), support efficiencies of up to 99 % and high frequency operation. Certainly, this leads to higher electromagnetic noise disturbances which can affect the functionality of the system and therefore need to be taken care of with adequate EMC measures. AVL’s unique EMC simulation approach and ten years of EMC experience help to avoid unnecessary efforts and extended development time. This model-based simulation starts at the early stage of concept development and oper- Figure 3 Overall powertrain optimisation is critical to achieve performance & cost targets ates simultaneously through every progression.

The key drivers for charging are comfort (e.g. inductive charging) and quick recharging for long trips (e.g. fast charger) with possibilities of tions between components support very efficient powertrain systems. wireless charging. Our solutions and holistic development approaches Benefits are fewer sources of EMC radiation, less connectors, cables and (e.g. including EMC simulations) offer new and unique solutions result- interfaces. AVL offers the strong integrations of inverter, e-motor and ing in added value for our customers. Vehicle-to-grid connections like gearbox into the e-axle. By doing so, size, weight and cost reduction can on-board chargers entail security gaps. AVL’s development processes be achieved in addition to best performance at maximum system effi- ensure secure charging as well as protection of the vehicle-to-grid con- ciency. Furthermore, we offer the integration of e-drive components into nection against unauthorised trespass. AVL is working on innovative the vehicle. concepts for reduction of charging time like high power chargers and smart charging communication software. Latest concepts enable battery AVL provides a vast range of development and engineering services for charging via new inverter technology with the benefit of reducing weight every xEV component from light-duty to heavy-duty vehicles: auxiliaries, and additional components compared to conventional charging systems. power inverter, DCDC converter, charging devices, e-motors and e-axles.

Finally, the importance of a well-designed drivetrain needs to be empha- AVL’s long-year expertise in the powertrain sector is based on numerous sized. Its overall efficiency is the sum of the performance of individual and successfully completed customer projects. This was achieved thanks subcomponents but also their integration into the powertrain unit. Es- to the technical know-how and was supported by own in-house develop- pecially highly integrated e-axles and the optimisation of the connec- ment and simulation tools. 

33 Expert Forum cti magazine · December 2018

Expert Forum How will Connectivity and AI Change Future Powertrains? Cars are increasingly connected with each other and with their environment. And at the same time, artificial intelligence (AI) is about to revolutionise automotive technology. This opens up many new possibilities for the powertrain as the heart of the vehicle. What are the expectations of our drivetrain community experts?

“Vehicle systems will be integrated in the customers’ digital environment”

In my opinion the coming years will be shaped by four main trends. The biggest change will come as a result of the progression of autonomous driving. In powertrain development, new dynamic handling functions will gain relevance, for example in motion sickness prevention.

The second major change, closely linked to that, is Car2Car communication. Data from the navigation system, cameras, radar and laser sensors is already collected and processed, enabling powertrain optimisation in response to external conditions. An expansion of Car2Car communication and linking to HERE Real Time maps will unlock further potential. Information relayed from the cloud, such as localised icy conditions and obstacles, will allow optimising the powertrain configuration quicker and more precisely.

A further trend is Big Data. Today, large amounts of data are generated by numerous sensors in the vehicle. Evaluation of this data would allow better forecasts of component condition, ensuring a more targeted customer service and improved reliability through component failure prevention.

The fourth big trend is customisation, requiring the integration of vehicle systems in the customers` own digital Dr. Nikolai Ardey, environment. Powertrain signals can be integrated into this environment via apps. Very soon, customers will be Head of Development Powertrain, able to check the condition of components. In the future it will even be possible to customise the powertrain Audi character. These trends will permanently change the nature of development work for car manufacturers and lead to further improvements in customer service and comfort.

34 cti magazine · December 2018 Expert Forum

“Connectivity and combined learning benefits operation of all vehicles”

Connectivity and artificial intelligence will change largely how the powertrain will be engineered, operated, and serviced.

Connectivity will enable software over the air updates, i.e. necessary firmware updates can be made without visiting a dealership. Connectivity will also enable location-specific parameterisation of the powertrain that is based on the location (mountain, city, desert…). Performance, efficiency, comfort etc. can be adapted with parameters that are much more specific than data stored on the vehicle could be. Online databases provide many more databases, especially if they learn from a large number of vehicles, which specific data is actually most suited for certain environmental conditions. Through connectivity we learn from all vehicles how to best operate the powertrain and that combined learning benefits operation of all vehicles.

Another benefit through connectivity is condition-based maintenance. Vehicle data gets fed into an advanced analytics program, and thus can forecast when maintenance is due or which parts might fail. This also relates to artificial intelligence. Optimising powertrain operation parameters under certain conditions and the analysis for maintenance include artificial intelligence in terms of pattern recognition and neural networks, determining an Sven A. Beiker, PhD, outcome typically better than a discrete algorithm. Lecturer in Management, Stanford Graduate School of Those ideas might be close to what is already discussed much today and appear less visionary when thinking Business about 2035. However, implementing them in production vehicles will require some effort on the operations side of OEMs and suppliers, which is why one should be mindful of what actually will be commonplace by 2035.

„A new era of powertrain development with exciting opportunities“

We are facing an incredible transformation of the powertrain, which is at the core of all major transformations of the automotive industry. First of all, electrification is developing extremely fast – with all-electric vehicles, but also with all kinds of hybrids. Moreover, electric assistance is in all other systems in the car: suspension, A/C, braking, steering, supercharging, etc.

But the picture is even broader, connectivity will bring drastic evolutions. For example, predictive energy management and over-the-air uploads will allow the vehicle to enhance its software intelligence and get extra miles. Permanent connectivity will allow to find charging stations whenever needed along the way. Paradoxically, this will make vehicles more exposed to hacking, cyber security is becoming a stronger concern for new powertrains.

Cars are connected today, tomorrow they will be autonomous, affecting the powertrain too. For example, autonomous cars like robot-taxis will not be sporty; speed management linked to e.g. safety and ACC, will certainly have an impact on the vehicle’s dynamics. Safety features linked to ADAS will have to be managed via the powertrain as well, such as emergency braking or torque vectoring. Michel Foressier, Valeo Powertrain Systems AI will also play a role in electric energy management interacting with the driver. It will enable you to find the Business Group R&D best route, best driving conditions, best use of the vehicle systems. It is likely that with permanent big data and Marketing Director analysis, the powertrain will improve itself along lifetime.

This is a new ecosystem where everything interacts. We are entering a new era of powertrain development with exciting and unexpected new areas, and it´s a fantastic opportunity for the powertrain community to transform in a modern way.

35 Expert Forum cti magazine · December 2018

“Connectivity and AI can hugely improve efficiency, reliability, and comfort”

With brilliant and disruptive thinking everywhere, the question isn’t about when driverless cars are coming or when all vehicles will be fully electric. The question is about who is ready for these transformative shifts. As a mobility technology company and leading supplier in the automotive industry, we are focused on delivering on what’s needed today while creating innovations that society doesn’t even know they need yet. For Magna, the car doesn’t just have technology, the car is technology. And mobility is all about moving things – efficiently, safely and also profitably. It’s important for us to stay ahead of things like vehicle connectivity and AI even from a powertrain electrification perspective.

When looking at the drive system specifically, connectivity and AI can hugely improve efficiency, reliability, and comfort. The further vehicles can predict what’s ahead, the more functions like proactive shifting or predictive charging are feasible. In a larger context, hybrid models of transport and ownership may generate offerings like customer-specific operating strategies or load monitoring to control drivetrain condition. We can use this kind of data for even more efficient and reliable component design.

Swamy Kotagiri, As we continue to leverage our deep systems knowledge across the entire vehicle combined with our legacy Chief Technology Officer of of driveline leadership, we are in a unique position to deliver new mobility solutions for tomorrow. With a focus Magna International, on autonomy and electrification, our company of entrepreneurs are laying the groundwork for smart cars and President of Magna Powertrain smart cities.

“Machine Learning and connectivity are critical for shared autonomous vehicles”

Contemplating drive systems almost 20 years into the future may seem to be the work of crystal balls, but at GM, we are striving to invent the future and lead the industry transformation to connected and shared autonomous vehicles (SAVs). We are driven by our strategy of Zero Emissions, Zero Crashes and Zero Congestion, developing both near-term strategies to improve existing vehicles and propulsion systems along with defining the path forward for our customers and our company.

As industry leaders in vehicle electrification and connectivity, with OnStar and the most 4G LTE enabled vehicles in the industry, we are delivering customer features and learning customer behaviours faster than ever before. Data rich understanding of true customer usage has helped our engineering teams focus on what customers really value and how we can make their transportation experiences better. The Maven car sharing brand has allowed rapid understanding of shared mobility experiences, including shared Bolt EVs. This has enabled first hand understanding of this trend, at its infancy, and how it will mature.

It is clear to us that the future is electric. The opportunity to deliver transportation solutions that are safer, have no emissions and improve congestion in urban centres will happen. To lead this transformation, our SAV pro- Larry Nitz, pulsion systems will be all electric. Machine learning and connectivity will be critical to delivering SAVs in large Executive Director, Global numbers across the most demanding urban environments, globally. Propulsion Systems, GM

36 cti magazine · December 2018 Expert Forum

“Future vehicles will generate knowledge by using operational data”

Very essentially, connectivity and AI allow changes of vehicle attributes in the use phase during operation, rep- resenting a paradigm shift in automotive technology. Up to now, vehicle attributes have been optimised and tested only during the development phase, and the release of start of production has required a freeze of design and software functions. Future vehicles will be characterised by knowledge generation using operational data, permitting a self-optimisation of single vehicles as well as an entire fleet. This is enabled by applying machine learning either online or offline as well as sharing and distributing results in the fleet via connectivity. -Fur thermore, the growing knowledge base will be considered in the agile development phase of successor vehicles.

Three new aspects focussed by the research cluster “Vehicle 5.0” at TU Darmstadt represent examples we expect. Virtual online testing during operation including an automated release process for machine learned Prof. Stephan Rinderknecht, functions will be used for vehicle drives just like for autonomous driving. Optimised lightweight design will be Head of the Institute for achieved by considering the resource requirement for the entire fleet based on analysed big data of the use Mechatronic Systems in Mechanical phase as parts under extreme loads are exchanged selectively, safely and without on-cost on fleet level. Reduc- Engineering, TU Darmstadt tion of fleet consumption will not be rated using standardised but agile drive cycles, synthesised using big data of the real multidimensional user behaviour by considering speed, acceleration, slope, ambient temperature, etc.

“AI will be intertwined with vehicle hardware and infrastructure”

Autonomous driving functions will become part of everyday mobility in the long run, ranging from micro-mobility right through to heavy duty transportation. Artificial Intelligence is a common attribute here. With its ZF ProAI supercomputer, ZF has already set a course for implementing these driving functions in volume production. This electronic super-computer plays a vital role in our strategic objective to provide system solutions for our “Next Generation Mobility”.

Here, networking in the cloud plays an important role. In addition to processing the dataset produced by the vehicle, it will be possible to plan traffic movement more effectively because ZF ProAI has the capacity to integrate data, remote from the vehicle, into the on-board vehicle control. Equally, last-mile logistics can be designed with greater flexibility – the ZF “Innovation Van” concept of 2018 highlights what can be achieved, to date.

For vehicle drivetrains, a world of interesting possibilities opens up. Energy management and optimised route planning for electric vehicles, predictive maintenance functions for commercial vehicle drivelines, all compatible with over-the-air updates, are just a few ideas that we are developing that offer great potential. Wolf-Henning Scheider, CEO The key element to note is that these not only comprise “pure” AI or software functions. Rather, they include in- ZF Friedrichshafen AG novative functionalities which must always be closely intertwined with the vehicle hardware and infrastructure, providing the user with a comprehensive and customised mobility experience.

37 Oerlikon cti magazine · December 2018

Efficient Synchronizer Solutions for (Dedicated) Hybrid Transmissions

Dipl.-Ing. Nils Weber · Dr-Ing. Marcus Spreckels · Oerlikon Friction Systems

he targets of future regulations for automotive CO2 emissions re- The main requirements to synchronizer systems for hybrid transmissions Tquire increased engineering efforts and innovative solutions from the are a compact design as well as high performance and efficiency. A com- OEMs and their suppliers. Automotive powertrains will have to be opti- pact design especially in axial direction is required, because additional mised to highest possible efficiency to play their part in the future. That components like the electrical motor must be integrated into the existing includes a consequent reduction or power losses and weight of automo- space of a conventional powertrain. Oerlikon Friction Systems gives the tive gearboxes. However, the emission targets can hardly be achieved by right answer to those requirements by presenting the new ESync sychro- efficiency improvements of the conventional powertrain only. The pre- nizer family, which is designed to save as much space as possible without ferred technology to fulfil the requirements are electric vehicles especial- any limitation to the function or comfort. ESync enables our customers ly hybrid electric vehicles in parallel, serial or torque split configuration. and partners to develop the most efficient hybrid dual clutch (HDCT) and Hybrid powertrains in parallel configuration require special transmissions dedicated hybrid transmissions (DHT). to combine the power of the combustion engine and the electrical motor. This could be conventional dual clutch or even automated manual trans- S³ – Segmented Synchronizer System mission upgraded with an electrical motor or dedicated transmissions for The advantage of the Segmented Synchronizer System is the reduction hybrid powertrains. Synchronizer systems will still have their place inside of weight and increase of efficiency by reducing the number of compo- the future transmission to provide fast gear changes for an economical nents and friction surfaces. The S³ is able to replace double cone and operation of the combustion engine. triple cone synchronizers consisting of three components and two or three friction sur- Those market challenges triggered Oerlikon Friction System to develop faces by a two-piece single cone design advanced and innovative synchronizer solutions in order to support our without impact on performance. customers and partners to address the above-mentioned requirements.

The Segmented Synchronizer System S³ with the high performance Carbon friction lining EF®8000 is the ideal solution for performance and efficiency upgrades of existing conventional gearboxes. The S³ concept provides the same performance like multi-cone synchronizers with less components. By reducing the weight of the transmission as well as a significant reduction of drag losses, theS ³ concept is the right answer for cost- and fuel saving transmissions now and in the future. The Segmented Synchronizer System can be easily integrated into existing manual (MT) or dual clutch transmissions (DCT) without major modifications.

38 cti magazine · December 2018 Oerlikon

The concept of a conventional synchronizer is limited by a conflict between shift quality and torque capacity. A small cone angle reduces the shift time by increasing the torque capacity, but could also negatively influence shift quality. A larger cone angle provides good shift quality, but reduces the torque capacity and therefore increases shift time and shift force. Higher torque requirements need to be realised by multiple cone synchronizers with the consequence of increasing costs, weight and reducing efficiency.

The Segmented Synchronizer System is separating the function “synchronizing” and “releasing” by using a split friction ring with two different cone angles; the concept allows a reduction of the friction cone angle below the physical limit of conventional synchronizers. During synchronization, the blocker ring embraces the split ring and the inner small cone angle of the friction ring is providing the synchronizer torque. After synchronization, the larger outer cone angle of the friction ring allows the blocker and the friction ring to separate easily for a comfortable gear engagement. The benefits of the segmented synchronizer system are obvious:

››Reduced drag torque due to a reduced number of friction surfaces  up to 40 % ››Less weight by reduced number of parts  up to 20 % ››Space reduction in radial and axial direction  up to 13 % ››Cost saving  up to 30 %

S³ can be used as a drop-in solution for existing MT and DCT transmissions. The replacement of a multi-cone system by the Segmented Synchronizer System S³ requires minimal modifications only; no changes to the hub and sleeve are required. The innovative friction ring can be combined with conventional brass or steel blocker rings.

S³ is a perfect system to upgrade existing transmission for higher efficiency, lower weight and reduced space.

Figure 1 S³ replaces multi-cone systems

39 Oerlikon cti magazine · December 2018

Figure 2 Redesigning the gearwheel by removing material Figure 3 ESync in different designs, multi-cone andS ³

ESync – Space-saving design for future transmissions With the new revolutionary design, ESync even shorter package length To achieve future emission requirements, the number of hybrid cars will of up to 28 mm can be achieved for single cone as well as multiple cone increase significantly in the next years. The largest portion will be plug- synchronizers. in hybrid vehicles (PHEV), which still need transmissions to connect the combustion engine and the electric motor to the drivetrain. The mechan- Looking inside the buildup of a conventional single or multi-cone syn- ical complexity of such transmissions is increasing, as additional compo- chronizer it can be seen, that in shifted condition the flow of engine nents need to be integrated, for example electrical motors and actuators. power goes directly from the hub via the sleeve to the teeth of the gearwheel. Overthinking the major challenges for a transmission designer, As the available space in a vehicle is limited, the additional components like weight- and space-saving, this material is not required. require a consequent space optimised design of all components. That means for the synchronizer components a significant reduction in axial Removing the unused material creates a weight benefit up to 20 % com- package length. pared with a conventional system. ESync is integrated inside the gearwheel, filling the free space with single or multi-cone synchronizer sys- The package length of the conventional system has been reduced incre- tem or even with S³. mentally in the past by: ››Using smaller spline module / Reduced chamfer angles In combination with a new design of the hub, the dimension of the sleeve ››Stronger hub design due to smaller struts could be reduced and saves additional space between both gearwheels. ››Indexing without lugs By using the ESync concept with a new hub and sleeve design that pack- ››Smaller friction surface by using high performance carbon age length is reduced to less than 30 mm. ››Higher strength materials and production method for the hub The benefits of such a design are: The typical package length of a conventional synchronizer is 40 mm from dog plate to dog plate. A package length of 34 mm is feasible by con- ››Less weight  up to 20% sequently pushing the design to the limits of material and production ››Space reduction in axial direction  up to 30% tolerances.

40 cti magazine · December 2018 Oerlikon

Looking to simplify a complex transmission application?

Figure 4 ESync and S³ provides new possibilities for cost- and space saving

Transmissions pose a

In addition, a combination of the Segmented Synchronizer System S³ with the ESync concept is complex engineering possible taking advantages of both systems. This combination offers reduced space in combina- challenge. tion with a cost- and fuel-efficient design for innovative hybrid transmissions. They can contain up to 30 individual Conclusion bearings, each with its own performance By introducing ESync and S³, Oerlikon Friction Systems is offering a synchronizer system that criteria and role to play, and any changes gives new opportunities for the design of future transmissions. Both systems are not limited to in speciﬁcation have the potential to automated transmission like DCT and DHT; they are also available for manual transmissions. Oer- cause knock-on effects elsewhere in likon Friction Systems redesigned the conventional system concept in a consequent way. Oerlikon the architecture. Working with SKF Friction Systems is offering a revolutionary system which provides opportunities for cost- and as a single supplier, you will be able fuel-saving and is the perfect solution for the design of advanced transmissions. to access the full range of bearings for every driveline need, and the ››S³ increases the efficiency and reduces the cost and weight of a synchronizer system as a drop-in solution without compromising on the synchronizer torque capacity. By replacing multi-cone knowhow to navigate complexity and systems with S³, existing transmissions could be upgraded and get more cost- and fuel-efficient. bring every component together into ››ESync is a complete new approach to reduce the package length compared to a conventional a system that delivers the overall single or multi-cone system. performance you need. ››Due the outstanding performance of S³ and ESync, a high-performance carbon friction material is needed. Oerlikon Friction Systems offer this friction material withEF ®8000. As a global bench- To discover more visit SKF.com mark in friction characteristics and shift comfort, EF®8000 is also the perfect solution for overload capacity. With a thickness of 0,45mm it is also a space-saving option which is suitable for all kinds of transmissions for passenger cars, light, medium and heavy-duty trucks.

Depending on the customer request and application, Oerlikon offers a wide range of innovative products to save costs, weight and package length. All synchronizer systems can be used as an upgrade for existing transmissions or offers new possibilities in the design. 

® SKF is a registered trademark of the SKF Group. | © SKF Group 2018

SKF Powertrain Transmission Ad 297x70_v2.indd 1 06/04/2018 14:52 Marzocchi Pompe cti magazine · December 2018

Marzocchi’s Elika Leads a “Silent” Revolution in the Automotive Sector Marzocchi Pompe has been for the past 50 years a leader supplier of Gear Pumps in the industrial and off-highway mobile applications. Maybe not everybody knows that it is also a key player in the on-highway Automotive Sector.

Danilo Persici · R&D Dept. · Marzocchi Pompe

Figure 1 Applications of E05 Pumps family

ear pumps are volumetric machines widely used in hydraulic system design since a long time mainly be- Gcause of their unbeatable cost/efficiencies ratio and for their simpleconstruction and compactness.

Marzocchi Pompe is the manufacturer with the broadest range of displacement reaching as low as 0,12 cc/ rev and up to 200 cc/rev.

The top characteristics of quality, reliability of the Marzocchi products allowed the Company to gain an interesting share in the Automotive Market, where the most suitable range of displacement goes from 0,12 cc/rev and up to 8 cc/rev which is widely appreciated in all those applications where a mini powerpack is required.

The pumps are designed specifically to be part of theelectro-hydraulic system to generate a flow of pressur- ised oil in a controlled manner to drive the “actuators” required in most of the above-mentioned systems.

Standard application of Marzocchi Pompe products are easily requiring up to 300 bars while the limited operating pressure of the automotive application, generally up to 80 – 100 bars, has allowed design and process engineers to introduce several design and process optimisation with the goal on one side to maintain and even enhance very high performances specifically in terms ofefficiencies and noise and reducing overall sizes as well, and on the other side decreasing the manufacturing costs also with the adequate level of automatisation of the production and assembly of the units.

42 cti magazine · December 2018 Marzocchi Pompe

Figure 2 Evolution of E05 Pumps family Figure 3 Structural Analysis of E05 body pump

The automotive family of E05 Pumps has been specifically designed to Because of everything said before, Marzocchi can definitely provide the be integrated into assemblies of automatic transmissions, semi-auto- right answer to the specification that TIER1 or TIER2 engineers are look matic clutches, electro-hydraulic power steering, AWD systems, assis- ing for: tance in hybrid-type of propulsion, suspensions’ systems, trucks rear- steering etc. The main parts of the pump, before being physically built, ››High efficiencies to cope with limited current and voltages requirement have been subjected to structural verification throughFEA simulations, ››Low noise in order to reduce NVH (noise, vibration, harshness). in order to check in advance, the structure of the pump subject to the ››Limited overall dimensions in order to cope with packaging restraints stresses of work and also to verify the behavior during the most critical ››Competitive pricing versus standard pump solutions stages of the manufacturing process. A completely new automotive-dedicated Despite their small size, E05 Pumps, depending on the application cha- Production Plant racteristics, can be internally mono or bi-compensated, the compensa- Starting from 2016, the automotive pumps had been produced in a new tion system must always maintain the compensation plates in contact plant completely focused on the Automotive Pumps. In the new factory with the gears ensuring in all operating conditions, a drastic reduction of of more than 9,000 m2, located in Zola Predosa, just 5 kilometers from internal leakage, adequate lubrication of the moving parts and excellent the headquarters of the Marzocchi Pompe, 80 people work. The pumps volumetric and mechanical efficiency. Synthetic oils used in the automo- are produced on semi-automatic assembly and testing lines able to guar- tive industry generally have a low viscosity, as it must maintain adequate antee the high quality and contamination standards that the automotive fluidity even at low temperatures, down to even –40 °C. The low viscosity sector requires. The Plant’s ISO IATF 16949 Certificate has been updat- of the oil has imposed a fine tuning of the compensation system. The ed until May of 2021. compensation system has been designed to reduce the inevitable friction components increasing the mechanical efficiency of the system. The best for last – The ELIKA Family of High mechanical efficiency has a direct effect to lower consumption and Silent Pumps becomes larger enable a reduction of the size of the other components, such as a re- Thanks to the birth of the ELIKA1P, the range of available displacements duction in the size of the electric motor required to move the micropump. of the ELIKA family is once again increasing. This time the development concerns smaller displacements with a standard range from 2.1 up to A reduction of internal friction also entails a reduction of the heat input 8.1 cm3/rev. This family is particularly suitable for automotive solutions, in the hydraulic circuit. Reducing the volumetric losses is also possible to where the producers are increasingly required to produce silent mini reduce the size of other components such as the radiators: lower the in- hydraulic power units for lifting systems, large hydro guides or rear ternal leakage of the pump means lower heat that should be then taken steering systems for transport vehicles and others. Like all automotive away through oil cooling. solutions, Marzocchi is widely available to collaborate on customised solutions for shapes and sizes.

43 Marzocchi cti magazine · December 2018

Figure 4 Helical Gears of ELIKA1P Figure 5 New ELIKA ELIK1P

ELIKA itself is a highly efficient, low-noise and low-ripple Gear Pump, The specific design of its helical gears ensures the continuity of the motion designed and manufactured by Marzocchi Pompe. Its realisation is a re- despite the low number of teeth. The low number of teeth reduces the sult of a close cooperation with the Engineering Faculty of the University fundamental frequencies of the pump noise, producing a more pleasant of Bologna and its development brought to many patents and trade- sound. The shape of the ELIKA Profile, patented by Marzocchi Pompe, marks registered by Marzocchi. eliminates the encapsulation phenomenon typical of standard gear pumps by thus eliminating the main source of noise and vibrations. ELIKA Just recently (09 November) at EIMA 2018 in Bologna its Multiple Ver- tooth profile, without encapsulation,significantly reduces pressure- sion was awarded a Technical Innovation Prize with the following quote oscillations and vibrations produced by the pump and transmitted to by the commission: the other components, reducing the noise of the Hydraulic System.

The particularly low level of noise produced by the ELIKA pump makes it particularly suitable for applications which currently employ much more “Elika is a Solution for external gear pumps expensive technologies such as screw pumps, vane pumps, or internal that allows the same design of gears gear pumps. ELIKA, with its characteristics, is the ideal solution regard- previously reserved for individual pumps ing a wide range of specifications such as rotation speed, operating pres- to be used in modular architectures, to sure and viscosity. The structure of the ELIKA pump minimises leaks and reduce vibrations and noise.” maximises volumetric efficiency in all conditions.ELIKA is therefore particularly suited for applications, which use inverters or variable-speed drives to regulate the speed of the actuators. 

ELIKA’s Helical Gear Technology is the perfect choice for all low-noise level applications. The ELIKA gears reduce the noise level by an average For further information on Marzocchi Pumps: of 15 dBA compared with a conventional external gear pump. [email protected]

44 www.drivetrain-symposium.world

Walter Henrich uses CTI Symposia “The CTI Symposium is unique in the way it attracts the right quality of people in every year to ﬁ nd new contacts sufficient numbers.” and sales opportunities Bernd Henrich, CEO WALTER HENRICH GMBH

Focus The Objective

Walter Henrich is a manufacturer of rotor shafts and tubular – Enhance relationships with existing and potential customers products for the automotive industry. From the beginning, we and suppliers who see the company’s product range as part as a family business have always focused on cooperation which of the vision for future business is based on trust. Our focus is not only internal, but also with – Find an event for automotive businesses to discover new our customers. opportunities available in the market Our goal is to build long-lasting relationships and partnerships – Find a team that works tirelessly to create a strong network locally and also globally. We are looking for products with high among businesses and potential entrepreneurs technical requirements. After visiting the CTI Symposium in 2010, the decision was made to exhibit in Berlin in 2011 for the fi rst time. Since we started, Walter Henrich has been exhibiting in Berlin and from Results 2014 onwards also in the US. – Walter Henrich has attended CTI Symposia for 6 years now and has found a potential market that fi ts its products – Based on panel discussions and the information given by CTI “We like the whole CTI Symposium during the diff erent symposia, our company was able to dis- atmosphere. The concept of the event cover more ideas for our business with the conference, the exhibition and – We had the chance to be part of major decision- making processes for future related projects the opportunities to build a network is – Signed contracts as a result of new important for our business. It’s a great contacts generated at CTI Symposia place to show new products and no other – Productive discussions with custo- event offers such a good opportunity.” mers and various possibilities to identify future cooperation options Thomas Schmidt, with them Sales Manager WALTER HENRICH GMBH Haver & Boecker cti magazine · December 2018

Individually developed transmission oil filters and exhaust filters made of metal wire mesh. Maximum Particle Retention In All Dimensions Metal wire mesh products find a wide range of applications within the automotive industry and are used, among other things, to protect automatic transmissions and turbochargers in passenger car diesel engines. These filters are produced according to extensive customer and quality management requirements and specifications. Haver & Boecker’s Automotive business unit, which is certified according to IATF 16949, produces transmission oil filters and filters for exhaust aftertreatment to ensure a long service life of diesel vehicles.

Klaus Sklorz · Head of Automotive Unit · Haver & Boecker Christina Kemper · Marketing of Automotive Unit · Haver & Boecker

Transmission oil filter with or without plastic injection moulding By pleating the wire mesh, the Transmission oil filters made of wire mesh are used both in the suction transmission oil filter achieves oil filters and the control plates of automatic transmissions. Besides re- the largest possible filter quiring an exact fit, both types of filter must be extremely durable. This surface. pertains to the stability of the filter and its retention capacity. Metal wire ©HAVER & BOECKER mesh allows uniform filtering performance over the entire filtering surface and can be flexibly processed. The wire mesh can be individually shaped to provide the largest possible filter surface. Haver & Boecker has already developed transmission oil filters with flat, single-fold and pleated meshes. Producing extremely smooth mesh surfaces to avoid Haver & Boecker produces cross leakage of transmission oil at the wire intersections of the wire filters in all shapes and sizes mesh, for example, is just one of the success stories of Haver & Boecker’s including single or multiple layer, pleated or flat filters with Wire Weaving Division. The intensity and sequence of the individual pro- edging or plastic injection cessing steps not only have an impact on the filtration properties but coatings. also the stability of the products and are therefore an essential part of ©HAVER & BOECKER product development. The mechanical, chemical and physical properties, such as corrosion and heat resistance can be adapted to the particular application by selecting the right weave and material of the wires and the filter components. If required, a plastic edging additionally stabilises At first glance, the shape and structure of some transmission the transmission oil filters and makes them easier to install. Apart from oil filters do not appear to be standard plastics such as PA66, Haver & Boecker also processes special made of wire mesh. types of plastic such as the heat resistant PEEK. ©HAVER & BOECKER

46 cti magazine · December 2018 Haver & Boecker

Wire mesh filters reduce nitrogen oxide emissions Wire mesh filters are also used in exhaust aftertreatment systems of diesel engines in order to achieve the prescribed emission limits. These include urea filters for injection systems. Deep-drawn filter cloth – such as mesh with plastic injection coating with a diameter of less than 10 mm – allows for the largest possible filter surface and reliably retains ultra-fine particles. Wire mesh filters also offer the best prerequisites for NOx reduction through low-pressure exhaust gas recirculation (LP EGR). LP EGR filters retain all particles that exceed the Depending on the installation requirements, low-pressure exhaust filters maximum permissible particle from Haver & Boecker are available as round parts or ready-to-install size of 200 microns. moulded parts. These allow a high exhaust gas flow rate and retain all ©HAVER & BOECKER particles that exceed the maximum permissible particle size and would damage turbochargers and engines. Adapted to the ambient conditions, they have an extremely high heat resistance. Compared to the square aperture mesh, the 3D mesh developed by Haver & Boecker reduces the pressure loss by up to 36 % and the larger wire surface ensures a high particle retention rate.

Extensive testing and documentation accompany the production process In order to comply with customer-defined filtration parameters such as air permeability and pressure loss values without elaborate and costly trial testing, GeoDict simulation software is implemented to determine the optimal specifications for this application even before the filters are produced. Final verification of the simulation values occurs in the in- house laboratory within the Wire Weaving Division. Haver & Boecker de- velops its own mesh as well as the tools and equipment for further processing up to and including interlinked production lines. A 100 % camera in-line test is used to visually monitor products manufactured in large Simulation of the flow behaviour of the square aperture mesh (1) and the 3D mesh (2) lots. In this way, the final filter is completely documented.  using GeoDict software. ©HAVER & BOECKER

More information www.weavingideas.com/en/filters-and-fabricated-parts/

47 Methode cti magazine · December 2018

Torque Sensors for High Volume Production Applications Methode Electronics’ achievements in magnetoelastic sensor technology enable torque measurements in previously unfeasible serial production applications.

Julius Beck, Engineering Manager MST · Methode Electronics

Misconception in the Market Technology Description One common misconception still held by most people in the automotive Magnetoelastic torque sensors make use of a physical phenomenon industry is that measuring torque accurately and reliably is too expensive called the Villari effect, discovered in 1865 by Italian physicist Emilio Vil- for high volume production applications. This misconception originates lari (1836–1904), which states that a ferromagnetic material will change largely from the most commonly used technology in the automotive its magnetic properties when subjected to a mechanical stress (e.g. due industry to measure torque – strain gauges. Strain gauge type sensors to an applied torque), creating a magnetic anisotropy. Ways to exploit require extensive manual labour during application, fault susceptible te- this effect to measure torque have been researched for more than 30 lemetries and recalibration due to aging effects, making them expen- years. One way is to magnetise a region of a shaft with two circumferen- sive and difficult to integrate. Consequently, the strain gauge type sen- tial bands as shown in Figure 1. sors are more suitable for use in test benches and prototype vehicles, rather than high volume production applications. In many applications, This magnetic encoding takes place only once during production and direct torque measurements essential for closed loop control systems remains inside the shaft for the lifetime of the sensor. In the stationary (e.g. transmissions) have been replaced by complex and often inaccurate secondary part of the sensor, highly sensitive sensor coils are placed in mathematical models, which only estimate the true torque value. close proximity of the magnetic bands around the shaft. These sensor coils pick up changes in the magnetic field emitted by the encoded shaft Advanced magnetoelastic torque sensors eliminate these inherent draw- caused by an applied torque, creating the sensor signal. The relationship backs of the strain gauge technology, while matching or exceeding it between applied torque and signal received by the sensor coils is linear, in performance characteristics, such as accuracy, repeatability, linearity, making any signal linearisation unnecessary. bandwidth and long-term stability. The combination of a highly automated assembly process and large scale production facilities of these A sensor that consists only of a magnetised shaft and a stationary hous- magnetoelastic sensors, allows for a low-cost torque measurement solu- ing containing sensor coils and an electronics PCB creates a truly con- tion ideal for high volume automotive applications. These include many tactless torque sensor with unique benefits compared to other compet- applications where it was previously uneconomical to measure torque ing technologies: directly and thereby giving up many potential application specific optimisations. Methode’s torque sensing technology is enabling manufactur- ››Non-contact: There is nothing attached to the shaft and no other mod- ers for the first time to realise these optimisations in high volume ap- ifications are necessary. In contrast to strain gauges, magnetoelastic plications. sensors do not require any fault susceptible telemetry or adhesives that cause long-term instabilities and have a limited lifetime.

48 cti magazine · December 2018 Methode

Sensor Coils Applied Torque

Magnetisation Bands

Figure 1 Magnetisation with two circumferential bands

››Durability: The sensor can be completely encapsulated and is suitable ››Long-term Stability: The magnetisation is permanent and the calibra- for harsh operating environments. It can be submerged in caustic liq- tion will remain constant over the lifetime of the vehicle. Using a gear- uids, exposed to high temperatures (up to 210 °C) and withstand con- box mounted magnetoelastic torque sensor, a long-term stability of tinuous and strong vibrations. It is insensitive to dirt. 480.000 miles was demonstrated. The sensor operated without fault or ››Performance: Accuracy, repeatability and linearity are comparable to change in performance characteristics. The test was only stopped due strain gauge sensors. The magnetoelastic sensors have an outstanding to the wearing out of gear teeth in the gearbox and torque could no dynamic response in comparison to any other known torque or force longer be transferred. Shown in Figure 3 are the test results regarding sensing technology. This extremely high signal bandwidth enables de- the deviation in sensitivity (± 0.5 %), offset (± 0.05 %) and hysteresis tection of engine cylinder misfiring (see Figure 2) and accurately re- (± 0.1 %). solves any other high frequency signal. ››Minimal Packaging Requirements: Small packaging and a flexible de- Recent Advancements sign that can be optimised for axial or radial space constraints makes it Through steady investments in R&D, Methode continues to make ad- easy to integrate the sensor. vancements in the magnetoelastic sensor technology, pushing the ››Certification: ISO 26262 ASIL levels are achievable and have been in boundaries of sensor performance and robustness, further reinforcing production for several years. its position as the technology leader. ››No Cross-coupling: In magnetoelastic sensors the torque/force measurements are completely decoupled, so that, for example, a torque One such achievement is the Dual-Dual sensor, which uses three instead sensor is not influenced by shear forces on the shaft. of two circumferential magnetisation bands. The two sensor coil pairs

Misfiring of Cylinder 1

Nm 2000 RPM 1 1 4 4 4 4 4 4 2 2 2 2 2 2 3 3 3 3 3 qu e[Nm] To r Torque raw Torque [Nm] raw raged ve raged Nominal/

A Figure 2 High bandwidth enabling detection of engine misfiring

49 Methode cti magazine · December 2018

share the central magnetisation band but each uses one of the outer Sensitivity bands, effectively creating two independent sensors. Achieving this re- on ) 2.00% dundancy is particularly relevant for safety critical applications.

ev iati 1.00% +/- 0.5% The magnetic immunity (i.e. the rejection of external magnetic fields such 0.00% as the earth’s magnetic field or application specific external magnetic 0 100,000 200,000 300,000 400,000 500,000 -1.00% fields) is critical in some applications and is already excellent in Meth-

-2.00% ode’s sensors. However, enhancements in the production process of key Sensitivity (% Sensitivity (% d Miles components of the sensor, combined with up-to-date sensor electronics, improve the characteristic of magnetic immunity to external fields even Offset further.

on ) 2.00% Innovations such as the Dual-Dual sensor, improvements in the produc- 1.00% ev iati +/- 0.05% tion process and continuing R&D efforts have allowed Methode to over- 0.00% 0 100,000 200,000 300,000 400,000 500,000 come challenges of the technology and bring it to a maturity that com- -1.00%

t ff se t (% d petitors have failed to do. O -2.00% Miles Industrial Scale Production The key element that has allowed Methode to make magnetoelastic sen- Hysteresis sors a serious competitor for strain gauge sensors is the industrialisation 2.00% of the technology. The industrialisation of a product that used to be as-

1.00% sembled in largely manual fashion has allowed Methode to produce in +/- 0.1% high quantities and at very competitive prices. The technology allows 0.00% 0 100,000 200,000 300,000 400,000 500,000 for a level of automation not possible with strain gauge sensors. Current es is (% deviation) -1.00% production facilities are located in Malta, Belgium, China, USA, Canada ys ter

H -2.00% and Mexico, having a combined capacity of over three million sensors per Miles year, equating to more than 10 000 sensors per working day. Figure 3 Long-term stability of sensor sensitivity, offset and hysteresis

• ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

•• • •••••••••••••• •••••••••••••••••••••••••••••••••••••••••••••••••  • • • • • • • •• • • ••••••••••••• ••• • ••• ••• • • •••••••••••• •• • • • ••• ••• • • ••••••••••••• NELSON, CANADA LONTZEN, BELGIUM ••• •••• ••• • • ••••••••••••

MONTERREY, MEXICO SHANGHAI, CHINA NASR, EGYPT F RE SN IL L O , M E X ICO

Figure 4 •• •••• Methode’s Production Locations

50 cti magazine · December 2018

Figure 5 Torque sensors integrated into e-Bike bottom brackets Current Application Examples Albeit still being lesser known than strain gauges, the magnetoelastic sensor technology is already an established technology that has been Further Applications proven in numerous high volume applications with millions of sensor out With the advent of autonomous driving more requirements where torque in the field today. has to be measured are created. Electronic Power Steering systems that include a torque sensor (such as the previously mentioned system) will The magnetoelastic torque sensor technology is used in Electronic Power become ubiquitous as more and more cars are featuring some form of Steering (EPS) products with a total of several million units produced a lane keeping assist system or even more advanced autonomous fea- since 2009. Methode’s proprietary Dual-Dual-Band technology provides tures. As the human driver is taking on a more passive role, an important the necessary redundancy in this safety critical application. Additionally, feedback loop is removed. To compensate this, the state of the vehicle high overload requirements make this a very difficult application for any has to be precisely monitored. For example, knowing the torque at each sensing solution and magnetoelastic is the only one known to provide a individual wheel can lead to advanced stabilising systems and prevent solution for a non-compliant sensor setup removing mechanical com- dangerous situations due to wheel slip. The competitive cost, robust- plexity and thereby providing a much more direct steering performance ness and small packaging requirements make the magnetoelastic sensor and improved driving experience. technology ideally suitable for such applications.

Another safety critical application where the magnetoelastic sensor A calibration stable for the lifetime of the sensor and an accuracy that is technology has proven itself is eBikes and pedelecs. The direct and ab- high enough to allow detection of even the smallest changes in behaviour solute measurement of the torque applied to the bottom-bracket by the that would indicate a possible malfunction make magnetoelastic torque rider, results in optimised motor control and smooth riding experience. sensors an excellent choice when it comes to condition monitoring and Methode is exclusive supplier of torque sensors for the current market predictive maintenance applications. A cost/performance chart compar- leader and a large number of other eBike motor and system suppliers. ing the magnetoelastic to other technologies is shown in Figure 6.

Methode has also worked together with a major German supplier for the A unique and specialised application that Methode is developing involves automotive and mechanical engineering industry supporting the design the measurement of the forces exerted on a tow bar when pulling a trail- of an electromechanical anti roll stability control system. This system is er behind a vehicle. In this application, instead of measuring torque, the designed to reduce the roll angle of large passenger vehicles at high cor- magnetoelastic technology is used to measure the vertical, horizontal nering speeds, improving driving comfort whilst simultaneously increas- and lateral forces the trailer exerts on the towing vehicle. These mea- ing vehicle dynamics and safety. The system is mounted between the left sured forces are used to calculate whether safe towing conditions are and right half of the stabilising bars and can either stiffen or decouple the met and constitute a critical component of future stability control sys- system depending on the driving conditions. The magnetoelastic torque tems. sensor is the underlying sensor technology that updates the system’s control unit with real-time torque values within milliseconds. The system Conclusion is used primarily in larger vehicles such as SUVs, with a total of about Due to their superior performance and competitive cost, magnetoelas- 100 000 of vehicles on the road produced since 2015 and a maximum tic torque sensors represent the first viable high volume torque sensor production capacity of 140 k per year. product solution. Summarising the magnetoelastic sensor technology:

Production Cost ››High Performance: Meets or exceeds strain gauge performance char- Transformer acteristics Laser Light (Shielding) Highly automated manufacturing brings cost down Angular Shift High ››Low Cost: Proven: multiple high volume automotive applications in the field today Surface ›› Accoustic Piezo Easy Integration: Small packaging requirements and no telemetry Wave ›› Strain Medium make integration easy  Gauge Laser Light Phase Shift Eddy Current Low Differential Magnetoelastic More Information Transformer MST Technology Do have a challenging application where you need to measure torque or other forces? Performance www.methode.com or email to [email protected] and/or Signiﬁcant competition Insigniﬁcant competition Magnetoelastic technology to [email protected]

Figure 6 Production cost/performance chart

51 Praewema cti magazine · December 2018

Future-oriented Optimisation of Ring Gear Production PRAEWEMA Antriebstechnik adds gear honing of internal gearings to its technology portfolio

Joerg Reinhardt · Engineering · PRAEWEMA Antriebstechnik

Tailor-made solutions for soft and hard-fine machining of the simple planetary set Based on a wealth of comprehensive expertise with its world-leading optimisation technology known as PRAEWEMA gear honing for external he DVS gearing specialist PRAEWEMA Antriebstechnik continues gearing surfaces, the DVS gearing specialist has now refined this tech- Tto expand its technological expertise in order to keep pace with the nology even further for the hard-fine machining of internal gearings. growing significance of planetary gear trains for automatic and particu- Supplemented by the use of the highly productive Power Skiving tech- larly electric vehicles, with the associated need for even higher-precision nology together with the possible integration of additional machining production of toothed gear components. The company from Eschwe- steps such as deburring, PRAEWEMA now offers an integrated package ge, North Hesse/Germany now offers holistic machining solutions for for high-precision soft and hard-fine machining of the simple planetary µm-precise production and optimisation of both external and internal set – in other words, now also for inner-toothed ring gears as well as gearings. Here is a detailed look at the market and technology leader’s outer-toothed planetary and sun gears. extensive expertise when it comes to the highly complex production of inner-toothed ring gears for planetary gear trains. While in the past inner-toothed ring gears were not expected to reach such high quality standards as outer-toothed planetary and sun gears, Planetary gear trains are predestined for installation in the powertrains things have now changed as a result of current powertrain develop- of automatic and particularly electric vehicles. Compared to conventional ments. There were two reasons for the lower quality standards in the spur gear stages, the planetary gear train makes it possible to divide the past. On the one hand, tooth root bearing capacity is less critical than in power flow in three or more strands. This permits higher transmission planetary and sun gears due to the more favourable geometrical condi- and reduction ratios to achieve greater performance density, while re- tions. On the other hand, suitable highly developed machining technolo- ducing weight and package aspects and improving running smoothness. gies were simply not available due to the comparatively small batch sizes As a result, they fulfil the existing need for higher torques with reduced of rings gears. package and weight for electric drives that stand out with higher motor speeds of up to 17 000 rpm. Increasing demands for the production quality of ring gears In terms of production, these factors lead to narrower geometrical tol- Up to now, manufacturers have enhanced the performance and NVH erances and thus the complex demand for even higher precision NVH- behaviour of planetary gear trains almost exclusively through continuous optimised machining of corresponding planetary gear train parts, refer- improvements to the machining quality of planetary and sun gears with ring particularly to the quality of necessary gearings. The DVS company a sequence of both soft and hard-fine machining processes. These parts PRAEWEMA Antriebstechnik in Eschwege fulfils these requirements with therefore offer high gearing qualities and strength values, and allow for a tailor-made technology, machinery and tool solutions for high-precision large number of toothing corrections. By contrast, the inner toothing of gear manufacturing and optimisation. ring gears typically made of tempering steel is usually just soft machined

52 cti magazine · December 2018 Praewema

Image 1 Possible process variants for ring gear production depending on user’s quality demands for the resulting ring gear

with no additional heat treatment as a rule after the gearing is finished. The result: limited correction possibilities and average strength values and toothing qualities, with a negative impact on wear and noise behaviour and thus on the functional efficiency of the powertrain.

PRAEWEMA has identified potential for optimising the production of ring gears. This demanded expertise not just in machining toothings but Depending on the user’s quality demands for the resulting ring gear, indeed in all process steps, and opened up scope both to enhance the Image 1 shows possible process sequences for the production of ring load rating through case hardening and to use precise, economically effi- gears. Variants 1 and 2 show the conventional manufacturing process de- cient hard-fine machining procedures after the heat treatment phase. To scribed above; the nitriding heat treatment option in variant 2 improves this end, the company developed and optimised corresponding soft and the load rating but has a negative impact on toothing quality. Variants hard-fine machining methods together with a suitable machine concept. 3, 4 and 7 show process sequences that optimise both load rating and

Image 2 Exemplary measuring results after PRAEWEMA gear honing of a ring gear’s internal gearing

53 Praewema cti magazine · December 2018

Image 3 Detailed analysis of distortions resulting from hardening processes is of essential relevance in the field of ring gear production

toothing quality. In each case, soft machining is followed by case hardening heat treatment. This hardening method, implemented for example by mandrel hardening or low pressure carburising followed by high- pressure quenching, may improve material strength but results in hardening distortion such as shrinking, ovality and ship-form (see image 3). Hardening then has to be followed by corrective hard-fine machining for important functional parts of the gear wheels, particularly the running gears and bearing seats.

Heat treatment improves strength but necessitates corrective hard-fine machining Image 3 shows a typical ring gear geometry for an automatic car transmission where the roundness and smoothness distortions were almost halved by specific process control of the hardening phase. Here due consideration must be given to the fact that a certain protuberance allow- ance has to be heeded during soft machining to prevent notches in the finished gearing. The quality requirements for soft machining can also be reduced within narrow limits due to the subsequent hard-fine machining. The same also apples to the possibility for toothing corrections. Variant 5 constitutes a stand-alone special case: here a pre-skiving process is followed by honing as part of soft machining in order to improve the surface quality. This process sequence deliberately tolerates the hardness distortion resulting from subsequent nitriding.

When it comes to hard-fine machining, here the DVS company opts for highly productive Power Skiving, respectively the PRAEWEMA gear honing that has been specially refined for inner gearing applications. Hard Skiving permits effective correction of hardening distortions without the characteristic feed marks. It is therefore suitable for the mass production of ring gears with slightly lower quality standards (variant 3) as well as a pre-machining for gear honing, as only very limited further material re- movals are necessary to minimise form deviations and pitch errors, thus achieving very high gearing qualities (variant 4). In variants 6 and 7, soft machining using Power Skiving and heat treatment with nitriding or case Image 4 PRAEWEMA Internal Gear Honing

54 cti magazine · December 2018 Praewema

hardening is followed by hard-fine machining using inner honing of the soft machined gearing. The latter variant is given preference for ultra- high stressed parts in view of the better load rating properties.

Highest surface and profile quality for internal gearing surfaces Just like the proven honing for external gearings, PRAEWEMA’s refined gear honing for internal gearings fulfils the highest standards for surface and profile quality of toothed parts so that ring gears can now be machined in hitherto unequalled productivity and manufacturing quality. The typical gear honing structure has a positive impact on the excitation characteristics of the gearing. Image 2 clearly shows the minimising effect on both surface structure and the parameters influencing noise and wear development, respectively pitch deviations. Powertrain manufacturers can therefore produce wear- and noise-reducing planetary gear trains with higher transmissible torques, exactly in line with the demands made for application in the powertrains of automatic and particularly electric vehicles. Image 6 Ring gear of a planetary gear train optimised with PRAEWEMA internal gear honing Economically efficient and precisely fitting original tool solutions for this process are available from the DVS affiliate DVS TOOLING, whose range covers the entire scope of tools needed for PRAEWEMA gear honing. This includes the completely new development of inner-toothed Vario Author: SpeedDr esser tools and outer-toothed honing wheels. As with the hon- Mr. Joerg Reinhardt, Engineering ing of external gearings, the VarioSpeedDresser also permits precise PRAEWEMA Antriebstechnik GmbH Hessenring 4, 37269 Eschwege, Germany dressing of the honing tool, or in this specific case the honing wheel, with a defined cutting edge and flexible definition of the tooth geom- Phone: +49-5651-8008-0, Fax: +49-5651-12546 [email protected], www.praewema.de etry. In combination with PRAEWEMA gear honing, it is thus possible to make geometric adjustments respectively flank line corrections while at the same time applying exact finishing to the gearing surfaces. As such, it comprises a milestone in the field of hard fine-machining of hardened Media contact: internal gearings of gear components.  Diskus Werke AG c/o DVS Technology Group Mr. Oliver Koch-Kinne, Head of Communication Johannes-Gutenberg-Str. 1, 63128 Dietzenbach, Germany Phone: +49-6074-30406-40 [email protected], www.dvs-technology.com

Image 5 The platform for internal gear honing – PRAEWEMA SynchroForm V

55 BorgWarner cti magazine · December 2018

Thermal Hydrodynamic Optimisation of Grooves in a Wet Clutch

Mohsen Behzad · R & D Engineer · BorgWarner Transmission Systems Viren Saxena · Team Leader Analysis & Simulation · BorgWarner Drivetrain Engineering Michael Schaefer · Sr. Manager System Validation · BorgWarner Drivetrain Engineering

1 Abstract same direction, we speak of a positive angle (PA) groove, and otherwise This study performs a detailed three-dimensional CFD analysis to in- of a negative angle (NA) groove. vestigate the thermal hydrodynamic characteristics of wet clutch plates with regard to different groove orientations. The model is capable of The results show that ATF volume and flowrate through the clutch are predicting the two-phase flow and thermal behavior of the ATF inside generally higher in a PA groove configuration than in its NA groove the grooves under slip conditions. The effects of different groove ori- equivalent. Hydrodynamic behavior of this kind leads to a higher cool- entations on the ATF flowrate and its heat transfer performance are ing efficiency in PA grooves, particularly for operating conditions similar thoroughly examined in the study. The CFD results show that the groove to the launch procedure, when there is a high relative speed. The ex- orientation has a significant effect on the cooling efficiency of ATF and perimental tests also verify thermal improvement of this kind when the clutch plate temperature and therefore on the overall performance of the groove orientation is changed from NA to PA. clutch system. 3 Methodology 2 Introduction Wet clutch surfaces are usually grooved to enhance their performance. 3.1 Numerical Description and Configuration Experimental and computation work was performed to provide a bet- This study uses a Eulerian two-phase laminar flow of air and ATF as well ter understanding of the groove effects on the thermal hydrodynam- as the Volume of Fluid (VOF) interface tracking method for simulations ics (THD) of the clutch plates and find the optimum design for groove under isothermal (zero heat power) and thermal conditions. For ther- shapes and orientations. In this study, 3D CFD simulations of air-ATF mal simulations, energy equations were solved for both fluid and solid two-phase flow in a grooved clutch plate configuration were performed regions while taking the conjugate heat transfer (CHT) between the cor- using the commercial software STAR-CCM+. The aims of the study are to responding interfaces into account. investigate the effects of groove orientation on the THD behavior of wet clutches in the engaged state and understand the underlying physics. Fig. 1 shows the computational domain consisting of the grooved region The groove (referred to as a shovel groove in the following) has a linear (fluid continuum), half of a separator plate (SP, solid continuum), a nomi- shape with an angle of orientation measured relative to the radial direc- nal gap (fluid continuum) between SP and the top surface of the lining tion (see Fig. 1). The terms positive and negative angle grooves are used as well as an extension close to the groove ID to represent friction plate to define the groove orientation with regard to the direction of rotation (FRP) splines. There are N = 56 shovel grooves distributed axisymmetri- of the separator plate (SP). If SP rotation and groove angle are in the cally on each FRP. For this reason, only 1/N of the grooves (including

56 cti magazine · December 2018 BorgWarner

Figure 1 (a) Schematic of clutch plates with shovel grooves and locations of SP/FRP. β is the groove angle relative to the radial coordinates and the arrow shows the direction of SP rotation; (b) computational domain; (c) model representation of realistic configuration (side views). The dashed lines in the model figure show the locations of different crossing planes referred in the results section.

the corresponding SP and gap) was simulated with periodic boundary conditions at the side surfaces of the domain.

In all simulations, SP and FRP were rotated in the same direction. The flow boundary condition at extension ID (inner diameter) and groove OD (outer diameter) of the fluid region was set to a constant ambient pressure. This allows for flow into (also known as backflow) and out of the domain. Under this boundary condition, it is assumed that only air can enter the domain from OD. On the other hand, both air and ATF are allowed to enter the domain from the extension inlet boundary. However, if the calculated ATF mass flux at any face with an initial ATF Volume Frac- tion of VFATF = 1.0 is more than the averaged input mass flux, an air-ATF mixture is assigned at that cell, i.e., 0.0 < VFATF < 1.0. Figure 2 Temporal variation (time increases from left to right) of VFATF for (a) NA groove and (b) PA groove in NA/PA-FRP=0rpm cases on G-Mid (groove) and G-Top For the thermal analysis, the local heat flux was defined on the basis of planes. the contact pressure and a constant friction coefficient μ = 0.14 as follows: 4.1 Isothermal ˙q(r,t) = μ.p.ω(t)rel.r [1] Fig. 2 shows the isothermal temporal variation of the ATF volume fraction on G-Top and G-Mid planes for both NA and PA grooves after 0.10 s where r and t represent radial location and time respectively and is the of simulation. In this diagram, air is represented by white (with VFATF = relative speed between SP and FRP defined as ω(t)rel = ω(t)SP – ω(t)FRP. 0.0) and ATF is shown in blue (with VFATF = 1.0). The contact pressure was back-calculated from the total torque transferred during the tests. As shown for the NA groove, air intrudes into the domain from OD shortly after the SP speed ramps up to its target value ω(t)SP = 1700 rpm (coun- 4 Numerical Results and Discussion ter-clockwise), and it eventually reaches into the vicinity of the groove ID. The isothermal results in the first part of this section show significant In addition, the SP rotation causes air to be drawn into the gap from the differences in the hydrodynamics of the ATF for different orientations, top part of the groove, forming streaks of air in this region. Air intrusion leading to the important thermal effects we shall discuss in the second of this type from OD to ID is similar to the inward flow pumping reported part. To evaluate the heat transfer effectiveness of the different cases, on in previous numerical-theoretical studies for wet clutches. the following CFD results were focussed on in particular: On the other hand, for the PA groove in Fig. 2, a mixture of air and ATF ››Effective ATF flowrate through the clutch (i.e. flowrate at groove OD) flows into the grooved region from the ID. As in the NA groove, air is also ››The amount of heat transfer to the SP and ATF drawn into the gap from the grooved region, leading to a two-phase flow

57 BorgWarner cti magazine · December 2018

Figure 3 Velocity vector and magnitude for (a) G-Top and (b) G-Mid planes. Arrows Figure 4 Comparison of ATF flowrates at groove ID/OD for PA and NA patterns. show the inward and outward flow for NA and PA grooves respectively.

regime in the gap. A visual comparison of the VFATF results indicates that highest temperature is observed at NA-FRP = 0 rpm, followed by NA- the total volume of ATF in the domain is higher in PA grooves than it is FRP = 1000 rpm and PA-FRP = 0 rpm. In all these cases, the maximum in NA grooves. temperature occurs at the SP-gap interface, close to the OD boundary. Fig. 5 plots the temporal variation of the averaged temperature on the SP To analyse flow fields in NA and PA grooves, the relevant velocity vectors symmetry plane (SP-Sym) along with a bar chart of the total heat power and magnitudes (on the G-Top and G-Mid planes) are plotted in Fig. 3. transferred to the SP and fluid regions at 1.0s. The low heat transfer to As the diagram shows, a shear force generated by SP rotation causes the fluid at the top surface of the groove (G-Top plane) to move towards the side walls of the groove (in ± X direction). It eventually impinges on the wall and flows deeply into the groove (in –Z direction). After the flow reaches the side walls of the groove, it is directed primarily at an obtuse angle, i.e. towards ID for NA grooves and towards OD for PA grooves. As a result, a vortical flow structure with a net inward flow for an NA groove and a net outward flow for a PA groove is created as shown schemati- cally by the arrows in the diagrams. Moreover, shortly afterwards in the NA groove, a region with a pressure slightly lower than the ambient pressure is formed close to the OD. This causes air to intrude into the groove core from the OD boundary, while ATF tends to flow close to the wall due to the spiral flow motion, as shown in Fig. 2.

4.2 Thermal As, in thermal simulations, the input contact pressure ramps up according to the torque, a volumetric heat source inside the solid shell is generated according to Eq. (1).

Although thermal cases have lower ωSPL than they do in isothermal cases, the flow fields in both cases are generally similar, that is, air intrusion from the OD into the domain for an NA groove, and air-ATF inflow from the ID for a PA groove.

Fig. 4 shows the ATF flowrates quantitatively for thermal cases. For the case PA-FRP=0rpm, the outflow rate at the OD (ATF flow-through) is higher in comparison with the case NA-FRP = 0 rpm. In the case NA- FRP = 1000 rpm, however, the FPL rotation generates a higher inflow of ATF at ID compared with the NA-FRP = 0 rpm groove due to the centrifugal effect as well as a low relative speed similar to that observed in isothermal NA/PA-FRP = 850 rpm cases.

Figure 5 As a result of the variation in the air-ATF flow of NA/PA groove orien- (a) Average temperatures of SP; (b) heat power transferred to SP and fluids and tations, different temperature fields are obtained in thermal cases. The the resulting ATF flowrate through the clutch.

58 cti magazine · December 2018 BorgWarner

the ATF for NA-FRP = 0 rpm leads to divergent temperature behavior 5 Experimental Results as observed in Fig. 5(a). Fig. 5(b) also shows the ATF flow through the This section discusses the measurements performed on the clutch to clutch (flowrate at OD boundary), which corresponds well with the heat verify the results of the CFD simulation. transfer observed.

5.1 Temperature Measurements To compare the effectiveness of heat transfer, the clutch was instrument- ed to measure the temperatures of the steel plates at mid-plane.

Fig. 6(a) shows a constant heat power load case in which 25 kW of heat power are generated in the clutch by maintaining a constant torque and a constant slip speed of 1000 rpm. The test is repeated with the NA and PA groove patterns and for two different rotational speeds of the friction plate. We can see that, when the friction plates are stationary, the NA pattern has a low heat transfer rate, resulting in a continuous rise in the SP temperature. Heat transfer improves with friction rotation at 1000 rpm. In contrast, the PA groove pattern shows efficient heat transfer for both friction plate rotational speeds. This behavior matches the CFD prediction and proves that the NA groove pattern offers high resistance to the ATF flow through the clutch, leading to a low heat transfer rate, in particular when friction plates have low rotational speeds.

5.2 Flow Measurements The flow measurements results, shown as hatched bars in Fig. 6(b), also show the expected behavior for the NA groove. This means that the NA groove has a low ATF flowrate through the clutch at a low FRP speed. The solid bars in the same diagram also show the CFD results with a similar trend with regard to flow behavior.

6 Summary and Concluding Remarks A detailed three-dimensional CFD analysis of the thermal hydrodynamic behavior of a wet clutch in two different groove orientations is presented here. The analysis shows that a significant thermal improvement can be achieved by selecting the correct rotational configuration. This becomes more significant at higher relative speeds and low friction plate speeds pertinent to launch procedure, hill hold and slow creeping. The CFD results show that the optimised groove orientation multiplies the heat tranfer to the ATF by 5. This could lead to approximately 100 °C lower Figure 6 clutch plate temperatures.  (a) Measured average SP temperature and (b) Measured and computed ATF flowrate through the clutch for 25kW of heat input and a slip speed of 1000rpm.

59 Means cti magazine · December 2018

The New Building Blocks of Propulsion Systems Design How Means has developed new tools for transmission engineers to reinvent the design of efficient and compact electrified propulsion systems

Carl Beiser · Technical Business Manager · Means Rich Marr · Marketing Analyst · Means Tim Hunter · Marketing Manager · Means

housands of solutions for a handful of critical challenges. That’s one Way Clutch) that expanded the options to multi-modal controllability. Tway to characterise the automotive industry in the 21st century. This new system offered OEM transmission manufacturers a solution that would reduce system mass, improve efficiency, and offer additional Figuring out how to get a person from point A to point B as efficient- packaging flexibility. Use of a CMD can result in about 100 W energy ly, inexpensively, and now as cleanly as possible, should be a relatively savings at freeway speeds, when compared to a Roller / Friction Pack straightforward proposition these days. We’ve had over 100 years to combination. Today this technology can be found in 8, 9 and 10 speeds figure out the best propulsion system architecture for moving a vehicle being produced around the world. For the GM version of the CMD that down the road, yet the spectrum of solutions remains overwhelmingly went into the 9T50 Hydramatic transmission, Means won a GM Innova- vast. Meanwhile, the cost of these systems continues to climb. And the tion Award in 2016. Means has now shipped over 40 Million MD and CMD gamut of global and regional regulations which must be adhered to? clutches to date. Convoluted at best, as the complexities continue to grow. New Age, New Answers – Electrically Actuated So where does one start? Many OEMs take the approach of improving Clutches on existing technology. This can be an attractive approach because cur- But as we approach the next decade, the answers of the past simply rent powerflows are time-tested and vetted, with billions of miles driven won’t be able to address the same questions anymore. While some re- as validation. The problem with this approach is the fact that any future gions will cling to ICE propulsion, others are embracing the race to elec- gains at this point are incremental at best, where capital is invested on trification like never before. No one yet knows what the winning solution marginal improvements providing only fractional MPG gains or emissions will ultimately be, so multiple paths must be explored to ensure viability reductions. in the new mobility landscape.

A potentially more attractive solution is developing entirely new technol- One of the new answers that Means is working on is a static, electrically ogy, exploring new frontiers and disrupting the entire landscape. How- actuated CMD (CMD-e) which provides the unique benefits of latching ever this can be a daunting journey to undertake for established suppli- in state and not requiring a constant power supply. Because an electric ers, which must manage the risks of launching new projects that are not motor is present in such propulsion systems, precise synchronization is yet time tested and potentially cannibalise legacy business, all the while achievable which minimises the benefits of a passive overrun strut set navigating the subsequent overlapping investment in the old and new. and allows for two independent controllable locking elements to be used.

The Journey Begins The passive overrunning strut set is replaced by a single locking ele- Means first entered new space over 20 years ago by launching the Me- ment which is operated by a solenoid. A second single locking element chanical Diode (MD) One-Way Clutch, a strut-based system that me- is used to transmit torque in the opposite direction. Independent control chanically locks instead of using friction. The technology was successful of each solenoid allows torque transmission in the clockwise (CW) and because it was easy to integrate, was more torque dense, able to run at freewheeling in the counterclockwise (CCW) direction, or visa versa. Si- higher speeds, and resulted in reduced drag torque. The MD played a key multaneously engaging both solenoids creates the clutch brake function role in helping propel the 6 speed automatic transmission from a niche (no-way clutch). See Figure 1. product to a staple of the global automotive industry. Means’ new static CMD-e design can improve system level efficiency in An innovation to take this to the next level was the Controllable Mechani- two ways. First, hydraulic control is completely eliminated, along with all cal Diode (CMD), a Selectable One-Way Clutch (also known as a Two- of the cost and complexity associated with it. Second, power is only con-

60 cti magazine · December 2018 Means

Figure 1 Static CMD-e Figure 2 Dynamic Controllable Clutch (DCC)

sumed during state transition. The solenoids are bi-stable, meaning they Unlike the static CMD-e clutches, the dynamic functionality does not al- latch in state which eliminates the constant power demand. Once the low for solenoids to be used to engage and disengage the locking ele- locking element engages, power is removed and magnets in the solenoid ments. Therefore, Means uses a new type of actuation system called a hold the plunger in place. Because the locking element is torque locked, linear motor, which can control the locking elements while both races the magnetic latch does not have to be large. are rotating.

New Age, New Answers – Electro-Dynamic Clutches The linear motor is comprised of two components called the stator and However, static clutches are only half the answer. Transmissions of all translator. The stator is the stationary component and is fixed to the kinds also need dynamic clutches, or clutches which have two rotating transmission case. It consists of copper wire coils and steel plates. The races. Wet friction clutch packs, dog clutches, and synchronizers are two coils are wound in series with reversed polarity relative to one an- commonly used in dynamic clutch positions and have been around for other (anti-series). The other component is called the translator, which is decades. These solutions are suitable to electric propulsion systems, but assembled to, and rotated with, the pocket plate. The translator consists system efficiency and packaging are compromised due to complex -hy of permanent magnets, steel plates, and plungers that operate the lock- draulic systems needed to control these clutches. ing elements.

Means’ answer to the compromise is the new Dynamic Controllable Figure 3 details how the linear motor controls the DCC’s locking ele- Clutch (DCC), which packages in dynamic clutch positions and is elec- ments. The plungers within the translator assembly directly contact the trically-actuated. The DCC has two rotating races, the pocket plate and locking elements and cause them to pitch up or pitch down depending notch plate. The pocket plate contains two sets of locking elements; one on actuation direction. When the translator moves from off to on, the set for CW and the other set for CCW engagement. During engagement, plunger contacts the locking element, causing it to pitch upward so it can the locking element simultaneously contacts the pocket and notch en- engage into the notch plate. The clutch is able to transmit torque after gagement faces which allows the clutch to transmit torque. See Figure 2. the locking elements are engaged. A return spring under the locking ele-

Figure 3 DCC Modes (Left: Freewheel 0/0 mode and Right: Lock 1/1 mode)

61 Means cti magazine · December 2018

ment is compressed during the engaged state. When commanded off, the translator moves back toward the off position and plungers lose contact with the locking elements. The compressed return spring creates a force that causes the locking elements to pitch downward, or disengage. Once a torque reversal occurs, the locking element can disengage and the clutch can freewheel.

Figure 4 shows the linear motor assembly in the off and on positions. To change state from off to on, electrical current energises the coil nearest to the translator. The energised coil produces a magnetic field, which re- pels the steady state field generated by the permanent magnet while the far coil produces an attractive field.

The combination of repelling and attracting from the stator coils causes the translator to move. Once the translator passes over the center stator steel, the permanent magnet attempts to fully align the leftmost steel plates of the stator. However, the mechanical off stop prevents full alignment, which results in a biasing force that holds the translator in the on position. The translator is magnetically latched in the on position.

Similar to the bi-stable solenoid, the magnetic latching allows the electric power to be removed whenever the device is not actively changing position. After 50 to 150 ms, the electrical current is turned off as change of state is achieved and is no longer needed. The magnetic latching force eliminates energy consumption during steady state conditions.

To disengage the DCC, current is applied to the coil nearest to the translator (formerly the far coil) and the linear motor moves from the on stop to the off stop in a similar manner described above. The off mechanical stop prevents full alignment of the permanent magnet and rightmost steel plate of the stator, remaining magnetically latched in the off position.

Bringing It All Together The value of these two new clutch technologies reaches another level Figure 4 DCC Linear Motor Positions (Top: Translator magnetically latched in Off when the two systems are used together. For example, when the shift- position, and bottom: On positon) ing concept is employed in a BEV architecture, the need for hydraulics is eliminated, meaning there is no more need for the pump, valve body or torque converter. The friction clutches are replaced by low spin loss mechanical clutches, and no energy is required to hold these clutches. The low energy consumption, lighter weight, and high torque capacity make Putting It In Drive this an ideal solution for the wide variety of electrified vehicle architec- Perhaps the greatest differentiator from these new technology advances tures expected to populate the global automotive landscape within the is the flexibility they offer. These building blocks of electrified propulsion next decade. systems allow transmission designers to create simple solutions that add a whole new level of sophistication to the electrification of the automo- The DCC can replace synchronizers within simple gearboxes such as bile. More speeds can be added to the transmission, efficiency is mark- AMTs and DCTs, and improves overall packaging by eliminating com- edly improved, and it’s all done without needing more packaging space. plex shift fork-based actuation systems. Shift fork actuation systems are The added benefits of low energy consumption, lighter weight, and high eliminated and the linear motor actuation system packages completely torque capacity are all gained when these clutches are used in concert. inside the transmission case. Whether the system is used in a DCT, AMT, BEV, HEV, PHEV or DHT, the The technology really takes off when these clutches are connected to a Means Static CMD-e and Dynamic Controllable Clutch provide OEMs planetary gearset, such as the proven and popular Ravigneaux gearset, with proven solutions to many of the fundamental challenges that the or the slightly more efficient Simpson gearset. This combination allows electrification revolution will pose, now and in the future.  for the creation of simple multispeed gearboxes comprised of only a gearset, input and output shafts, several electric clutches, and housing. www.meansindustries.com

62 www.drivetrain-symposium.world

SKF celebrates 10 years of reliable rotation and collaboration with CTI

SKF has been an active participant at the Car Training Institute (CTI) since 2008. A lot has happened in the automotive industry since then.

For example, the development of manual transmissions in Europe is no longer a clear and linear pathway from 4 to 5 and 6 speed. Automatic transmissions are not only for premium and US cars. Continuously variable transmissions (CVT) are not just associated with Japanese cars.

So what will be the transmission of the future, which gearbox concept will emerge victorious? Lots of questions.

We may not have all the answers but, over the years, SKF has benefi tted from learning about trends and developments at CTI congresses in Berlin, Shanghai and Michigan. This has helped us to gain insights and input, and to inform our future concept development in areas such as CVTs, double clutch transmissions, hybrid and transmissions for electric vehicles.

SKF has enjoyed a close collaboration with CTI. We see it as an excellent platform through which to interact with key opinion leaders in the driveline community. We look forward to working with the CTI for a new decade of We have also used to congresses to present and get early feedback on new products, solutions and innovations including our collaboration and innovation! energy effi cient bearing portfolio, double clutch bearing set, sensor bearings, bearings with ceramic balls and rollers, low friction seals, etc. Impressions from the 7th CTI Symposium China ›Automotive Drivetrains, Intelligent and Electrified‹, 19 – 20 September 2018 – Shanghai, China China’s Growing Expertise China is growing its domestic development competence in electrification, and at the same time opening up to external competitors. This year’s CTI Symposium China featured even more electrification-related topics – and even more internationalisation.

or the first time, the CTI Symposium was held under a new name: Under the incremental opening process, which starts with commercial F‘Automotive Drivetrains, Intelligent and Electrified’. However, it is vehicles and extends to passenger cars in 2022, the Chinese industry not turning away from transmissions, the symposium makes them part will square up to the competition and accelerate towards the long-term of a bigger picture. Almost four in five lectures dealt with electric and goal of emissions-free mobility. After the announcement in spring, there hybridised drives, as well as with development software, drive integra- was much speculation about what was behind the easing of the rules. tion, calibration, or operating strategies. Some see it as a concession to the USA, others believe China wants to suppress uncontrolled growth in the electrification sector – by enabling Transmissions for electric and hybrid drives were discussed in three spe- more competition and hence, faster market consolidation. cific categories: ‘EV Drive System Concepts’, ‘EV Transmissions Electric Components’ and ‘Dedicated Hybrid Transmission (DHT) and Hybrid Newcomers are driving innovation Drive Systems Concepts’. All three stand for real-life market require- CTI Symposium chair Prof. Ferit Küçükay picked up on that topic of con- ments in China now – not sometime in the future. solidation in the Podium Discussion on Day One. The panel members were Michael Schöffmann (Audi), Gerhard Henning (FECO Transmission As of 2019, automotive manufacturers must meet stricter annual quo- System), David Lu (Chery) and Zijing Lin (CH-Auto Technology). tas for New Energy Vehicles (NEV) in China. Under the Credits system, pure electric vehicles get more points than plug-in hybrids (see p. 81, Prof. Küçükay quoted a Wall Street Journal article saying there are cur- CTI Mag 12/2017). But alongside its stick-and-carrot approach to electric rently 487 companies producing automobiles in China. Of these, 357 are drives, the Chinese government is also relaxing the rules elsewhere, as ‘newcomers’ and just 130 are ‘old’ companies – a huge number in itself. announced in April 2018. As of 2020 Joint Venture Compulsion will be David Lu compared this to the 1920s in the USA, where there were 200 dropped, meaning foreign manufacturers can offer electric and hybrid auto companies, and the 1960s in Germany, when it still had lots of short- automobiles without a Chinese partner. run manufacturers. Today, only a small fraction remains. The question is: will China’s 487 auto manufacturers survive?

64 cti magazine · December 2018 Follow-up report

Michael Schöffmann thinks not all of them will. As he pointed out, there is more to automobiles than drivetrains alone – you have to master topics like crash protection etcetera too. Gerhard Henning, CTO of the newly-found- ed FECO Transmission System Corp. Ltd (a subsidiary of Great Wall Motor) added that on top of production, you also have to master sectors like sales and servicing; these call for tremendous expertise that start-ups could hardly be expected to have. David Lu said efficient mass production and profitability were ‘serious’ challenges among competitors that also applied to newcomers. Tesla, for example, had been on the market for quite a while, but was basically dependent on external capital, meaning stocks and shares. Zijing Lin, the Transmission chief engineer of sports car engineering Company CH-Auto Technology, agreed, but emphasised that fresh impulses from start-ups can also accelerate development.

The general consensus was that China would probably follow in the footsteps of Europe and the USA. Small, innovative companies would cooperate with, and often be absorbed by, established players. Providing rules and technologies in cost-critical sectors such as auto production do not change completely, the high number of manufacturers – nearly 500 – would drop long term.

How many speeds for electric drives? As in previous years, the panel also discussed how many speeds make sense in conventional drives, and now in electrified drives too. The debate over 10 or even 11 ratios for conventional drives seems to be over; not one of the conventional step transmissions presented in Shanghai (Aisin, Opel/PSA) had more than 8 gears. Schöff- mann said what really matters is spread, so the number of ratios basically follows the usable engine spread. And since most countries apart from Germany now had speed limits of around 120 km/h, there were hardly any applications for more than eight gears. For Schöffmann, improving internal efficiency is more important – for example by improving hydraulics and reducing friction loss.

What about pure electric drives? As Gerhard Henning sees it, only vehicles that go faster than 160 km/h really need two ratios. Schöffmann noted that in two-speed setups (several electric rear axle drives were shown in Shanghai), the biggest challenge was the large gap between ratios. Particularly with electric drives, comfort requirements were so high that ‘shift shocks’ were not acceptable. Hence, avoiding torque interruption when shifting under load would be a big challenge.

Kejian Wang, President at CH-Auto Technology, talked about this challenge in his plenary lecture incidentally. The Roadster K50 he presented does 0–100 km/h in 4.6 seconds, has an electric range of 420 km, weighs 800 kg – and has just one gear. Wang said the next model would have two ratios, ideally as an AMT – a real challenge as said above. Wang said longer-term however, the company is also considering multispeed transmissions with planetary gear sets.

65 Follow-up report cti magazine · December 2018

e-fuels again; so far, these do not earn credits or incentives anywhere, including China. He also noted that hydrogen enables much faster refuel- ling. Prof. Küçükay said the 350 kW chargers currently being installed in Germany, for example, can solve recharging issues to an extent, but also reduce efficiency to 70 percent. So for now, the general dilemma still ap- plies in China too: the only real benefit of pure electric drives is that they are local emissions-free.

Another well-attended symposium event was the press conference, where one journalist raised the question of battery CO2 footprints. Sym- posium chair Prof. Küçükay said if you only consider production, EVs need twice as much energy as conventional automobiles. The complexities of battery manufacturing are the main factor, and account for 40 percent of production energy. In countries like Norway that use virtu- ally 100 percent renewables, he said, that would not be an issue. But in countries with more coal in the mix, such as China, things were different. Given a European energy mix, a C-segment EV ‘emits’ 107 g/km of CO2 over its entire lifecycle; in China that figure is 170 g/km, compared to just 161 g/km for a conventional automobile.

How much electrification is right? China is setting the pace As mentioned earlier, China only issues Credits for vehicles with pure- What were the take-home impressions from this year’s symposium under electric drivability; ‘conventional’ hybrids have no benefits in terms of its new name ‘Automotive Drivetrains, Intelligent and Electrified’? With quotas. Yet most forecasts agree that even in 2030, at least 70 percent of 630 participants, it was bigger once again. But for conference director the world’s automobiles will still have a combustion engine, increasingly Sylvia Zenzinger, the quality of the Shanghai event was more important as part of a hybrid drive. than quantity. She was particularly pleased at the growing number of Chinese speakers and participants – a reflection of the extensive exper- One question the panel asked was how much sense 48V hybrids make in tise in the Chinese automotive industry. China. David Lu said there were no direct incentives, but the technology would obviously reduce consumption for the great majority of vehicles, Lectures on electric drives and components now play a much bigger role. which in the short term would not be NEVs in China either. This is why Opening the market so international vendors can operate independently Michael Schöffmann sees 48V in general as a ‘must’ for reducing CO2. will probably further accelerate innovation in the sector. We are expe- However, Gerhard Henning pointed out that China’s tech-savvy consum- riencing an exciting growth phase with an incredibly diverse range of ers want to ‘see’ the hybrid, and benefits need to be really tangible. participants. It is hard to predict whether and when consolidation might occur, as it did in Europe and America. But two things are certain: China According to Zijing Lin, drives with no pure-electric mode will dominate is setting the pace in electrified drives, and the CTI Symposium is more for a long time, and we need solutions there too. The bottleneck, he said, important than ever in an international context. was still the battery with its low energy density and very long charging times. At this point Michael Schöffmann raised the idea of CO2-neutral Gernot Goppelt

AUTOMOTIVE DRIVETRAINS | INTELLIGENT | ELECTRIFIED Print: ALBERSDRUCK GMBH & CO KG, Leichlinger Str. 11, 40591 Düsseldorf Publisher/ Business Address: Cover photo: CTI Symposium China Expo Car Training Institute (CTI) Layout: Hanno Elbert, rheinsatz, Köln A division of EUROFORUM Deutschland GmbH Print run: 3000 copies Toulouser Allee 27, 40211 Düsseldorf, Germany. Copyright Tel.: +49 (0)211.88743-3000 The articles in the CTI Mag are published by EUROFORUM Deutschland GmbH. www.drivetrain-symposium.world Literary copyright to all articles, illustrations and drawings contained therein is E-Mail: [email protected] held by the relevant authors. No part of the publication may be reproduced by any means, mechanical, electronic or otherwise, without the express prior per- Do you want to showcase your expertise in drive technology or place mission of the publisher and authors of the articles and drawings. The authors an advert? Contact [email protected] accept sole responsibility for the content of the articles.

66 fast forward solutions Electric Pump and Actuation Solutions for future mobility

3 DCT, AT, CVT, MT, BEV and DHT 3 Parking lock (x-by-wire) 3 Transfer case and AWD coupling 3 Limited slip differential

3 Contact Europe Herwig Moser Director Product Segment Drivetrain [email protected] +49 911 4504 1199 Robert Fabian Key Account Manager Automotive [email protected] +49 911 4504 1919 www.buehlermotor.com

We look forward to seeing you at: 17th International CTI Symposium 4 – 5 December 2018 | Berlin, Germany | Booth G19