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MARCH 20TH, 2020 across 11 different parameters accounting for five simulations each. One of the material parameters was changed from its initial value while the other parameters were kept constant. This was repeated until all New Brake Design Supports Modern E- values of the parameters were simulated. Additionally, the geometry of the sphere consisted of various editable parameters. These Motorcycles parameters consisted of the following: sphere radius, lining thickness, Hydraulic sphere brake delivers higher shell thickness, shell angular coverage, and the pressure angle. Like the material simulations, the geometry simulations changed one performance in a smaller package parameter at a time and held the others constant at an average value. Based on extensive simulation using Contact Mechanics under the ADINA script at PSC, brake torque is most sensitive to sphere radius, Aaron J. Lewis, Joe Fiore, and Jason Pintea shell angular width, angular width of the pressure application area, and the coefficient of friction. The sphere concept significantly outperformed the disc brake model despite having an 84% smaller brake effective radius. Results prove that a single sphere brake is Abstract approximately equivalent to three-disc brakes in terms of braking performance given a vehicle platform equivalent to a light duty pickup In this paper, a new design of a hydraulic brake system for electric truck. Increasing the sphere radius by a factor of 1.5, from 6cm to 9cm, motorcycles is considered with better technical characteristics and increases the brake torque by more than a factor of 3. Increasing the functional abilities in comparison to existing disc brake designs called sphere radius while keeping all other design parameters the same, the Hydraulic Sphere Brake (HSB). Using validated learning through results in a greater contact area as well as a greater moment arm for the the build-measure-learn (BML) feedback loop, minimum viable contact friction. This dual eﬀect is responsible for the large increase products (MVP) were rapidly developed that have been demonstrated in brake torque with the sphere radius. However, as the sphere radius in the lab environment. Advantages of developments in HSB increases, the weight of the sphere brake also increases. A factor of application include the following: 1) The first brake system which 1.5 increase in the sphere radius increases its weight by a factor of does not require tools to change brake pads; 2) Due to inherent design, 3.375. Finally, stopping distances were calculated for a light duty the brake itself produces more torque in a much smaller package; 3) pickup truck comparing sphere to disc brake systems. With only two The HSB is lighter than the required disc brake for the same platform; sphere brakes, the stopping distance is estimated to be about 46m. 4) It is positioned more towards the centerline of the motorcycle, Technically, one sphere brake per axle outperforms four-disc brakes at increasing stability and performance; and 5) The brake is affordable in each wheel end by almost 33%. This finite element analysis (FEA) high growth industries like e-mobility. The HSB has been installed on validated that the sphere concept appeared to be sound and competitive a Cleveland CycleWerks ACE motorcycle for lab testing. The new with existing brake technology. Furthermore, derivations of the HSB will be commercialized on Cleveland CycleWerks Falcon electric equations can be computed to determine sphere brake torque, sphere motorcycle (e-motorcycle). In this paper, results of experimental brake stopping distance, and comparative analysis with disc brakes in studies will be presented and discussed. The experimental results any platform. confirmed the validity of the theoretical propositions. The next step determined the feasibility in manufacturing a sphere Introduction brake system to assess the effectiveness behavior of a friction material regarding pressure, temperature, and speed for the brake system to The disc brake was invented by Frederick Lanchester back in 1902 validate FEA test results. To do this, Lewis partnered with Navitek when electricity was still in its infancy. Lanchester successfully Machining and Link Engineering. Several major achievements were integrated disc brakes on his Lanchester automobiles in Europe [1]. attained during this stage of development. First, the sphere brake can Nearly 20 years later, the Douglas Motorcycle Company used a be manufactured and tested on dynamometers. Second, the results version of the disc brake on their product lines. The Douglas was the from the dyno tests validated similar performance behavior that was first motorcycle with front and rear disc brakes to win the Senior TT captured in the FEA testing conducted at PSC. The sphere brake in 1923 rode by Tom Sheard [2]. Yet, it wasn’t until 1965 that disc prototypes generated significantly more torque than disc brakes in a brakes made their way to public markets. MV Augusta offered front much smaller package; nearly 3 times the required torque needed for disc brakes on one of their 1965 touring motorcycles. Honda light duty truck application despite a slightly lower coefficient of introduced the first hydraulic disc brake in 1969 on the popular and friction. Third, heat needs to be mitigated and is one of the most affordable CB750 [3]. Though incremental improvements have been important Critical to Quality (CTQ) attributes for consideration as made on disc brakes, true disruption has occurred in over 50 years. development progresses. The sphere brake was invented by Aaron Lewis back in 2010. After Given validation of the technology for light duty trucks, Lewis meeting with and receiving interest in the concept from a group of garnered support form a major commercial vehicle OEM to scale the executives within a prominent aftermarket brake company in Chicago, technology to Class 8 vehicles. Five challenges were presented to Lewis received seed funding from the Ben Franklin Technology complete the next iteration of the sphere brake. Those included: 1) Partners (BFTP) in Erie, PA to begin product validation. To derive Does not require a two-man lift; 2) Does not require wheel removal to sphere brake torque formula, Lewis partnered with The Pittsburgh service pads; 3) Has the fewest parts; 4) Is bolt-on; 5) Performs at the Supercomputing Center (PSC) at Carnegie Mellon University (CMU). same level as disc brakes. At the additional request of the Original The sphere brake model was rendered in Automatic Dynamic Equipment Manufacturer (OEM), a sphere driveline retarder was also Incremental Nonlinear Analysis (ADINA). The model consisted of the designed. Approximately 13 total units were manufactured. Of those upper right quarter of the design. ADINA simulations were performed 13, four service brakes were installed at the wheel-ends of a Mack test Page 1 of 8 | 2012 E. 33rd Street, Erie, PA 16510 | 814.898.4321x266 | www.spherebrakes.com Member SAE, NAMC, and DATC truck and one sphere driveline retarder was installed on the driveshaft. applied, hemispherical pads enclose on an outer sphere surface. This Test track demonstrations and one field test were performed on the inherent design allows multi-directional brake force application Mack test vehicle. All five challenges were met within 15 months. around the brake surface generating more torque with a smaller brake The efforts of the commercial vehicle iteration led to a Small Business effective diameter. For purposes of demonstrating the concept and Innovation Research (SBIR) contract with Marine Corps Systems how the HSB was designed and installed on an e-motorcycle Command (MCSC). To date, the sphere brake system has been application, reference Figure 1 below for the governing equations in designed on 3 military platforms with both pneumatic and hydraulic the following section. actuation. The bolt-on sphere brake shed over 50lbs. per wheel-end and it’s the first brake that doesn’t require wheel removal to change brake pads. To accelerate product commercialization and validation, the sphere brake has been scaled down to racing and two wheeled applications within high growth industries that promote innovation. Industries like electric motorcycles and scooters enable market entry that promote disruptive technologies without sacrificing quality over cost and affordability. The global electric two wheeled industry is estimated to reach $13,864 million by 2025 [4]. North America is estimated to reach $675.7 million by 2024, with a CAGR of 28.4%. US is the larger market in the North America region, holding 85% of the market share [5]. Furthermore, new electric motorcycle manufacturers are starting up across the US. Some are brand new. Others already have well established markets with internal combustion engine (ICE) product lines. One such manufacturer is Cleveland CycleWerks based in Cleveland, OH. A manufacturer who is launching their very first e- mobility platform, The Falcon. A platform that will feature exciting, new technology that has yet to be commercialized in any market. With lower barriers to entry and the speed at which development iterations can occur, Sphere Brakes (SB) partnered with Cleveland CycleWerks to launch the world’s first HSB for e-motorcycles. This paper proposes the first HSB for e-motorcycles starting with an overall description of the design, formulas for calculating torque, and considerations of optimizing the brake component setup to achieve Figure 1. HSB design for e-motorcycle application. desirable stopping

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