(19) *EP003257138B1*

(11) EP 3 257 138 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.: of the grant of the patent: H02K 21/24 (2006.01) H02K 3/26 (2006.01) (2016.01) (2006.01) 04.12.2019 Bulletin 2019/49 H02K 11/33 H02K 16/04

(21) Application number: 16748477.3 (86) International application number: PCT/AU2016/050060 (22) Date of filing: 03.02.2016 (87) International publication number: WO 2016/127207 (18.08.2016 Gazette 2016/33)

(54) ELEKTROMOTOR MOTEUR ÉLECTRIQUE

(84) Designated Contracting States: (74) Representative: Lavoix AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Bayerstrasse 83 GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO 80335 München (DE) PL PT RO RS SE SI SK SM TR (56) References cited: (30) Priority: 13.02.2015 AU 2015900464 WO-A1-2006/036201 CN-Y- 201 204 491 JP-A- H0 487 544 JP-A- 2009 153 358 (43) Date of publication of application: US-A- 3 382 570 US-A- 4 585 085 20.12.2017 Bulletin 2017/51 US-A1- 2006 202 584 US-A1- 2006 202 584 US-A1- 2008 272 664 US-A1- 2012 256 422 (73) Proprietor: Electric Vehicle Systems And US-B2- 8 006 789 Technology Pty Ltd Lang Lang VIC 3984 (AU) • SPOONER E ET AL: "’TORUS’: A SLOTLESS, TOROIDAL-, PERMANENT- (72) Inventors: GENERATOR", IEE PROCEEDINGS B. • QUICK, Duncan Richard ELECTRICAL POWER APPLICATIONS, 1271980 Snake Valley, Victoria 3351 (AU) 1, vol. 139, no. 6, 1 November 1992 (1992-11-01), • HEDDITCH, Duncan John pages 497-506, XP000343941, Grantville, Victoria 3984 (AU)

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 3 257 138 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 3 257 138 B1 2

Description Undervoltage on any single cell therefore leads to battery failure and therefore in a BEV, vehicle failure. The relia- TECHNICAL FIELD bility of the vehicle can only be improved by the use of two or more batteries. [0001] The present invention relates to a low voltage 5 [0009] Document JP 2009/153358 discloses a motor high current permanent magnet DC electromagnetic het- of known type. eropolar motor. [0010] Document US 2006/202584 discloses an axial rotary energy device of known type. BACKGROUND [0011] It is desired to provide an electric motor that 10 alleviates one or more difficulties of the prior art, or that [0002] As global oil reserves decline, the motivation to at least provides a useful alternative. develop battery electric vehicles increases. As a conse- quence, improvements to the range and weight of electric SUMMARY vehicles become economically desirable. [0003] To increase the efficiency of power conversion, 15 [0012] According to the present invention, there is pro- the system voltage in battery powered electric vehicles vided a permanent magnet DC electromagnetic heter- (BEVs) has increased over the past decade from around opolar motor having the characteristics defined in claim 1. 150V, to over 600V. Future systems of over 800V are [0013] Particular embodiments of the present inven- expected. The safety risks of electrocution and fire inher- tion are the subject of the dependent claims, whose con- ent in the presence of such high voltages can be man- 20 tents are to be considered as integrating part of the aged by methods such as chassis short circuit detection present description. and automatic isolation, manually operated high voltage isolators, and insulating gloves worn by emergency serv- BRIEF DESCRIPTION OF THE DRAWINGS ices personnel, but risk management principles would suggest elimination of the problem is a safer solution than 25 [0014] Some embodiments of the present invention either personal protective equipment (PPE) or engineer- are hereinafter described, by way of example only, with ing solutions. Eliminating the problems caused by high reference to the accompanying drawings, wherein: voltage (HV) batteries can be achieved by lowering the system voltage. However, as above-mentioned, design- Figure 1 is side perspective view of an electric motor; ers of BEVs are typically increasing system voltage, not 30 Figure 2a is a side view of the motor shown in Figure decreasing it. Increasing the system voltage reduces 1a; conductor size and cost, and increases the efficiency, Figure 2b is a section view of the motor shown in since the volt drop across IGBTs is lower at lower cur- Figure 2a through the line A - A; rents, reducing losses. Figure 2c is an enlarged view of section "B" of the [0004] BEVs use one or more batteries with cells in 35 motor shown in Figure 2b; series. Series cells require balancing circuits to ensure Figure 2d is an enlarged view of the section "C" of each cell has the same voltage. Typically, one cell bal- the motor shown in Figure 2b; ancer circuit is required across each cell. This means the Figure 3 is an end view of the motor shown in Figure use of very small cells leads to an expensive set of bal- 1; ancers. The function of the balancer circuit is well known 40 Figure 4 is a partly exploded view of the motor shown to those skilled in the art and need not be detailed herein. in Figure 1; Balancers are essential to reliably achieve the desired Figure 5a is a side perspective view of a of the charge - discharge range and a long service life for the motor shown in Figure 1; battery. Figure 5b is a side perspective view of a magnet of [0005] Even with cell charge balancers, the discharge 45 the rotor shown in Figure 9; depth of the cells does still vary with cell age, temperature Figure 6 is a side perspective view of a stator disc and other factors, so eventually with all series strung bat- of the motor shown in Figure 1; teries, a cell will fail, being forced into reverse polarity by Figures 7a to 7c are schematic diagram showing a the other cells, causing failure of the battery pack. circuit for a driver for one bar of the motor shown in [0006] Cell bypassing can be provided to ensure cells 50 Figure 1; do not over or under charge. However, only in very small Figure 8 is a side perspective view of another electric cell batteries, can cell bypassing circuitry be built eco- motor. nomically. Figure 9 is a side view of a stator of the motor shown [0007] For BEVs, cell bypassing is uneconomic, and in Figure 1; the whole battery has to be replaced after around eight 55 Figure 10 is a side perspective view of a sector of years. the stator shown in Figure 9; [0008] All series strung batteries require cell monitor- Figure 11 is a side view of a printed circuit board of ing to detect cell undervoltage and trip out the battery. the stator shown in Figure 9;

2 3 EP 3 257 138 B1 4

Figure 12 is a side perspective view of a battery; cludes a plurality of slots 38 being shaped to receive and Figure 13 is a schematic diagram of a power supply seat therein respective ones of the 16. The rotor for the motor shown in Figure 1; disc 14 includes a central hub 40 including an axially Figure 14 is a side perspective view of the motor extending slot for receiving the shaft 20 therethrough. shown in Figure 1 electrically connected to a power 5 The rotor disc 14 also includes a plurality of support mem- supply system; and bers 42 extending radially between the hub 40 the outer Figure 15 is a schematic diagram of a battery pow- circumferential section 18. Slots 43 are formed between ered electric vehicle. the support members 42 and the outer circumferential section 18. The slots 43 are shaped to assist with drawing DETAILED DESCRIPTION 10 in air axially through the motor 10 and expelling air radially from the motor 10. Airflow generated by slots 43 moving [0015] The brushless (DC) motor 10 air through the motor in this manner help cool the motor shown in Figures 1 to 4, includes a rotor 12 including a 10. The slots also help to reduce the weight of the motor rotor disc 14 and a ring of spaced apart permanent mag- 10. nets 16 coupled around an outer circumferential section 15 [0019] The hub 40 includes a fastener 44 for mating 18 of the rotor disc 14 in the manner shown in Figures with the shaft 20. As shown, the fastener 44 is a female 5a and 5b. The motor 10 also includes a shaft 20 extend- slot shaped to mate with a male protrusion (not shown) ing axially in direction "DA" through the rotor disc 14. The of the shaft 20. Alternatively, the fastener 44 is any other shaft 20 is in mechanical communication with the rotor suitable means for mechanically coupling the rotor 12 to disc 14 such that axial rotation of the rotor disc 14 causes 20 the shaft 20. axial rotation of the shaft 20. As shown in Figure 6, the [0020] As particularly shown in Figures 9 to 11, the motor 10 also includes a stator 22 that includes a stator stator 22 includes the driver switches 30 mounted cir- disc 24 having circumferentially distributed and radially cumferentially around respective bars 28 of the stator directed slots 26 therein that define corresponding radi- disc 24. The stator 22 includes busbars 46 that electrically 25 ally directed "DR" elongate electrically conductive bars couple the driver switches 30 mounted on stator printed 28. The motor 10 further includes driver switches 30, as circuit board (PCB) 31 to the outer ends 32 of respective shown in Figures 7a to 7c, electrically coupled to and co- bars 38 of the stator disc 24. located with radially outer ends 32 of the elongate bars [0021] As shown, the driver switches 30 are preferably 28 of the stator 22 and configured to generate alternating arranged in sectors 52 around the stator disc 24. In this current (AC) signals that flow along the elongate bars 28 30 embodiment, the sectors 52 around the stator disc 24 of the stator 22 in alternating radial directions "DR" so as are driven by a DC power source 50 that includes a plu- to generate a torque on the rotor and thereby cause the rality of batteries 51 (B1, B2, B3, B4), of the type shown axial rotation of the shaft 20. in Figure 12, arranged around the motor 10 in the manner [0016] As shown, the motor 10 includes two 22 shown in Figures 13 and 14. As shown, the batteries B1, 35 and one rotor 12. However, the motor 10 could alterna- B2, B3, B4 are connected in parallel to respective sectors tively include any suitable combination of stators 22 and 52 of the motor 10. As would be understood by those rotors 12 to suit the needs of any particular application. skilled in the relevant art, the motor 10 could use any For example, the motor 100 shown in Figure 8 includes number batteries 51 connected in parallel to service the four stators 22 and three rotors 12. However, for ease of sectors 52 of the motor 10 for a particular application. description, preferred embodiments of the invention are 40 [0022] As particularly shown in Figure 11, the driver below described, by way of non-limiting example, with switches 30 of each sector 52 are mounted on printed reference to the motor 10. circuit board. The PCB 31 of each sector 52 includes [0017] As particularly shown in Figure 4, the motor 10 terminals 53a and 53b for electrically coupling to respec- also includes a pair of rotor end discs 34a, 34b coupled tive ones of the positive and negative busbars 48 which, to the shaft 20 bookending the rotor 12 and the stator 22 45 in turn, couple the driver switches 30 to the DC power therebetween. The motor 10 further includes end plates source 50 in the manner shown in Figure 12. 36a, 36b coupling the rotor 12 and the stator 22 there- [0023] The DC power source 50 is preferably a battery between. As shown, the end plates 36a, 36b are gener- that includes a plurality of electrochemical cells connect- ally square planar members. However, plates 36a, 36b ed in parallel. The motor 10 operates with ultra low volt- could alternatively take any suitable shape to suit the 50 age. In this specification the terms "ultra low voltage" needs of the motor 10. The plates 36a, 36b include a (ULV) are taken to mean the voltage around that pro- fastener 37 for securing the component parts of the motor duced by a single electrochemical cell. 10 therebetween. The fastener 37 includes, for example, [0024] The parallel connected battery 50 provides bolts 37 extending through respective corners of the many simplifications to existing electric vehicle systems. plates 36a, 36b. Alternatively, the fastener 37 includes 55 The motor 10 is a simple to construct and advantageously any other suitable means for coupling the plates together. runs from around 3V, with the highest possible efficiency. [0018] As particularly shown in Figures 5a and 5b, the For a 100kW DC motor, this means a current of 33kA. outer circumferential section 18 of the rotor disc 14 in- [0025] The development of the motor 10 came from

3 5 EP 3 257 138 B1 6 starting with the requirement to carry tens of thousands 100Ω series resistor to limit the gate turn on current, and of amps at 3V. Historically, only homopolar motors are pulled down locally at the FET by a 1MΩ shunt resistor, used in such applications. A slotted homopolar disc rotor which is useful for ensuring the FET cannot turn on in was made and caused to run in a stationary magnetic the event the connection between the gate and the con- field, using brushes to force a radial current through the 5 trol circuitry is lost. This is most useful if the control card disc. Since a brushless cannot be is connected by a plug and socket to the FETs 58. In the made, and brushes were deemed too inefficient and embodiment shown, this is less necessary since the problematic to meet the project’s requirements, the het- FETs 58 are mounted on the same PCB as the control eropolar motor 10 based on the same slotted disc was logic, and connected by PCB traces. developed. 10 [0033] The driver shown in this example embodiment [0026] The heteropolar motor 10 is essentially a mul- is based on an IR2127 current sensing single channel tiphase axial flux multi stator 22 machine with a conven- driver. A further advantage of this low voltage motor 10 tional permanent magnet rotor 12. Each stator disc 22 is that both the high and low side FETs 58 can be driven may then be further segmented into sectors 52, driven by the same gate source voltage rail, since the high side by separate batteries 51, but otherwise a conventional 15 is only half of the supply rail above the low side. brushless DC machine, albeit with attention given to cur- [0034] This obviates the need for a boost driver for the rent path lengths. To this end, the controller switches 30 high side, and hence we can use the same circuitry are preferably, integrated with the motor 10 into the one shown in Figure 7a for both the low and high side FETs assembly. 58. The circuit for the high side FET in 58 is identical to [0027] In terms of efficiency, the homopolar motors are 20 that shown for the low side FET in diagram 30. The two surprisingly efficient, particularly if their losses can circuits together form one half bridge driver. be ignored, so the concept of having radial currents in a [0035] One half bridge driver is needed for each phase. flat conductor is not faulted from an electrical to mechan- Where the motor 10 is a four phase motor, so it has eight ical power transfer perspective. Homopolar machines IR2127 drivers, which driver phase A, B, C, D and their have the dual air gap, ironless rotor disc concept, without 25 complements, A’, B’, C’ and D’. To trigger the IR2127 suffering a loss in efficiency due to flux linkages, even driver, a simple connection to a hall switch would suffice. though solid disc machines tend to have curved and Rather than a switch, we show in this example an ana- spread current paths between their peripheral brushes logue hall sensor, fed to a simple op amp comparator, and central shaft. A solid disc rotor cannot however be which allows adjustment of the trigger point relative to used in a heteropolar machine due to eddy current losses 30 the position of the rotor magnet. This allows fine tuning in the disc 22 caused by the reversing field. of the timing of the motor. [0028] With a simple planar stator 22, the next design [0036] The motor will work with a simple hall switch step was to divide the current and drive individual bars connected directly to the IR2127 drivers, but to allow for 28 with a half bridge 54 to make a multi-phase brushless motor protection, an external stop button, throttle control, DC machine 10. 35 and reversing, more blocks are added in between the [0029] The motor 10 includes control logic 30 to drive hall sensor and the gate driver. Since we have already the half bridges 54. For example, the method for driving used an LM339 comparator, it is expedient to use the the bars 28 utilises a small number of operational ampli- same chip to provide these functions. The reverse / for- fiers (Opp Amps) and hall sensors. ward selection can be done by wiring the LM339 as an [0030] Figure 7a shows one possible embodiment of 40 AND gate, shown in Figure 5a as IC3A and IC4A. These a simple analogue electronic controller 30 for the motor gate either the north or the south pulse trains through, 10. Each stator bar 28 shown diagrammatically here as thus sending the driver a forward pulse train or reverse L1, L2, L3, and so on, is preferably provided with its own train, depending on the setting of the forward / reverse half bridge FET driver pair 54, particularly where the mo- selector switch, which could be a gear lever in an electric tor 10 is sized such that the maximum current in the bar 45 vehicle application. IC2A is wired as an OR gate to allow 28 is about the same as the maximum current capacity either of these trains through to the driver. of each FET 58. In this case, each bar 28 represents one [0037] Before the train can be sent to the driver, there phase of the motor 10. This minimises the back emf per is one final AND gate, which is used for protection. This stator ’turn’ and allows operation at the voltage of one again uses a comparator. The protection in this example electrochemical cell 51, even under heavy load with a 50 includes over temperature, emergency stop, a cross in- lead acid cell, which can be around 1V. terlock between high and low side drivers for any given [0031] The driver circuitry for the half bridges 54 can bar, and a throttle pulse train. An advantage of the LM339 be any conventional 3 phase , if there are as an AND gate is that any number of conditions can be three bars 28 under each rotor pole. However, this motor added by using additional diodes, three spare diodes 10 lends itself to having more than three phases, in which 55 have been shown. case conventional three phase motor controllers are not [0038] The LM339 is an open collector op amp, hence directly applicable. we need pull up resistors on the output, shown as R3, [0032] The gate of each FET 58 may be driven via a R4, R12 and R16. The IR2127 is a current sensing driver,

4 7 EP 3 257 138 B1 8 which lowers its FLT pin to ground when it senses over- radially aligned members 42) through slots 56 in the end current. Internally, it has an op amp comparator that plates 36a, 36b. measures the volt drop across the FET when it is con- [0047] The busbars 48 form heat sinks for the power ducting. Since the source / drain resistance is fairly con- transistors, which can be cooled on both sides. An stant, the volt drop is proportional to the current. As an 5 IRL6283 is one currently available package which allows added bonus, this voltage increases with increased FET cooling from both sides. temperature, providing over temperature protection, so [0048] The driver transistors 58 for the half bridges 54 that the FET will begin to not fire if it becomes hot under needed to be mounted physically close to the conductor currents near its overcurrent trip limit. bars 28, to eliminate the power loss from volt drop on [0039] To provide safe isolation of the motor, we can 10 any connecting leads, so the concept for mounting the open isolator 62 to cut the gate supply rail from the driver. control logic boards 30 right on the stator bar ends 32 [0040] Without gate voltage, the FETs form an effective was developed. As shown in Figure 10, the bar ends 32 isolation of the voltage from the motor, without the need have a hole 60 to receive a rivet, bolt or via, to ensure for a high current electrical switch. they are clamped to the circuit boards 30. [0041] Of course, any other control logic platform, con- 15 [0049] The busbars 48 to connect the battery 50 to the ventionally microcontroller based, or Field Programma- circuit boards 30 are as large as possible to conduct the ble Gate Arrays, or any combination thereof, could be current, and they are as short as possible. As such, the equally well used. The analogue control however is sim- busbars 48 are preferably integrated with the circuit ple, robust, cheap and requires no firmware or software. board 30, in the sandwich configuration shown in Figure [0042] To eliminate hysteresis losses, the stator 22 20 10, with positive on one side 48a, 48b and negative on magnetic circuit preferably does not include iron. The sta- the other. The busbars 48 extend out through the motor tor discs 24 are preferably made from a single sheet of casing to allow direct connection of the battery 50. conductive material, for example, a copper sheet, and [0050] No battery isolators are used. The FETs per- without any iron, the stator 22 incurs no iron loss. With form adequate isolation to prevent mechanical rotation the twin stator 22 single permanent magnet rotor ar- 25 by means of isolation of their gate supply, and there is rangement shown in Figures 1 to 4, using steel rotor end no requirement in a ULV machine to provide full current plates 34a, 34b to form the return path for the flux insures isolation for any increased electrical safety. an effective magnetic field shape does not incur hyster- [0051] To safely perform any work on the motor 10, esis or eddy current losses, since the steel rotates with the person simply may padlock the gate drive supply iso- the rotor, and does not see any change in flux. 30 lator 62 open. [0043] The effective air gap is the conductor width, [0052] Finally, to add modularity, the circuit boards 30 which is the thickness, of the stator disc 24 plus the thick- can be divided into any number of sectors 52 per stator, ness of the two mechanical clearance air gaps. In an typically two or four. axial flux embodiment, these gaps can be made quite [0053] To provide a light weight machine, the casing small, typically 0.3mm. With a stator disc 24 thickness of 35 36a, 36b may be aluminium, fibreboard or plastic. Since 1.5mm, the effective air gap is just over 2mm. Using N52 the stators 22 are so light, the casing has only to support magnets in the rotor, a flux density in the gap of 1.0T can the stator PCBs , and provide the torque reaction. be achieved. [0044] Previously, the highest efficiency machine de- Advantageous Features of the Motor 10: sign has been the , which typically uses fer- 40 rite in epoxy on the stator. The motor 10 avoids this by 1. A heteropolar machine, with high pole count, typically having the stator windings self supporting. The Lynch more than 24. motor loses some efficiency in stator hysteresis and end turn resistive losses, both of which are eliminated in the [0054] Lower pole counts are good for high speed mo- motor 10. Windage losses in higher speed machines can 45 tors, but require a large flux path traversing half way be minimised by making the rotor magnets 16 flush with around both the rotor 12 and stator 22; this means the the rotor yoke, rather than proud, and by using a thin iron has to be large. A high pole count minimises the flux solid rotor yoke instead of a spider; or, for a slower speed path and hence the iron or neodymium weight, since the machine, the magnets 16 can be made deliberately proud flux path in air needs to be minimised for maximum flux to form and function as a straight blade cooling fan, to 50 density. cool the stator bars 28. [0045] The rotor magnets 16 and rotor yokes are con- 2. A brushless DC motor 10 for high efficiency and reli- ventional technology, made simply from aluminium sheet ability. cut by subtractive milling, either with mechanical milling or water jet cutting. 55 [0055] All high power high efficiency EVs use brush- [0046] The exhaust air from the air gap, caused by the less motors, which are synchronous PM motors fed by a rotor 12, cools the circuit boards and busbars 46, 48. Air DC to AC variable frequency converter. is drawn in through the centre of the spider (that is, the

5 9 EP 3 257 138 B1 10

3. Utilises an ironless stator, for high efficiency and power 7. Utilises planar stator discs to minimize magnetic loss- to weight ratio. es.

[0056] Printed circuit board (PCB) rotor motors have [0062] A key feature of the motor 10 is the planar stator ironless rotors and zero rotor iron losses and a low cost 5 discs 24 with single turn bars 28 electrically communi- . They need brushes when the PCB is the rotor. cated. PCB rotors have previously been fabricated from However, the motor 10 achieves the same zero iron loss- double sided or multi layer boards, using vias or end con- es by making the slotted disc the stator 14, and electron- nections to make loops. Making a single plane armature ically commutating the bars 28 of the disc 24, causing means there is no wasted air gap of fibreglass or other the magnets 16 to be rotated, as for example is done in 10 nonmagnetic, non-conductive material. The design of the conventional ’outrunner’ brushless model aircraft motors. planar stator disc 24 of motor 10 gives the highest power to weight and smallest air gap for the size machine. 4. Provides optional modularity, as stator bars 28 maybe connected in sector groups 52. 10. Has very low winding impedance. 15 [0057] The number of sector groups 52 would be a [0063] As a consequence, the motor 10 has ultralow factor of the number of pole pairs, except 1. Constructing inductance and winding resistance, similar to a homopo- the motor 10 in sectors 52 allows redundancy, since each lar machine, which permits operation at ultra low voltages sector would have its own PCBs 31 and busbars 48, 46. and very high currents. 11. Has very low leakage induct- Each sector 52 may be connected in series or series / 20 ance. parallel connected, with some able to be bypassed, par- [0064] A further benefit of low winding inductance alleled or series connected for higher machine efficiency means that there is very low leakage inductance, that is, at less than rated output power, thus running the remain- less flux lines fail to couple the stator and rotor. This gives ing stators at higher efficiency. higher efficiency and power. [0058] Using two or more sectors 52 allows the stator 25 22 to be mechanically split, for easy assembly and dis- 10. Has low switching losses. assembly, without having to pull the rotor 12 magnet 16 assemblies apart. For example, a 12 magnet 16 rotor 12, [0065] Low inductance stator permits higher switching which has 6 pole pairs, could have 2, 3 or 6 sector groups frequencies with lower switching losses, further improv- 52. 30 ing efficiency. [0059] Optionally, sector groups 52 may be connected in series to achieve a higher voltage than a single bar 11. Can tolerate high starting currents. pair would achieve alone. This allows flexbility in machine design to suit a given system voltage. [0066] The un-insulated planar stator 24 of motor 10 35 permits very high starting currents and hence high start- 5. An axial flux machine, for accuracy of air gaps and ing torque, since the windings can be overloaded as their high efficiency. cooling is improved over conventional brushless motors, which required winding insulation. [0060] A typical embodiment of the motor 10 would be configured as an axial flux machine. It can be also built 40 12. Utilises simple conventional electronics. as a cylindrical radial flux machine, although accessing both sides of a radial flux (cylindrical) machine is more [0067] One embodiment of the motor control is to have difficult. each bar 28 individually controlled by one half bridge 54.

6. An axial flux machine, permitting different configura- 45 13. Minimises conductor losses. tions using common modules. [0068] Each half bridge 54 is preferably radially dis- [0061] Fitting a plurality of rotor 12 / stator 22 assem- posed at the end of each bar 28, minimising controller to blies along a common shaft 20 can also be utilized to motor cable length to zero. achieve the required output power and to match the re- 50 quired terminal voltage. Stacking axial flux machines is 14. Is inherently redundant. easier than extending the rotor length of a cylindrical ma- chine, since a cylindrical machine has to be made heavier [0069] The motor 10 as designed exhibits redundancy to ensure it is stiff enough to hold the air gap tolerance. down to individual stator bars 28. 55

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15. Can utilize mixed power sources, batteries and chem- 22. Modularity and Operating Voltage istries. [0077] The modularity of the motor 10 also means that [0070] The configuration of the motor 10 allows it to be stator sector busbars 48 can optionally be connected in fed simultaneously from different voltage sources 50, in- 5 series allowing the use of a higher voltage power supply. cluding those using different battery chemistries. The [0078] This configuration would obviate the many ad- voltage sources 50 could include ultracapacitor banks, vantages of a parallel battery system, but would none- or photovoltaic arrays, fuel cells and other low voltage theless embody a lightweight high efficiency motor for supplies. LV applications 10 16. Can both motor and generate simultaneously. The Battery Powered Electric Vehicle

[0071] DC motor 10 is capable of recharging some bat- [0079] The BEV 100 shown in Figure 15 at least in- tery banks while motoring from others. cludes: 15 17. Can both motor and generate simultaneously in 1. a chassis 102; smallest configuration. 2. surface engaging means 104 (such as wheels, tracks, a propeller, etc); [0072] DC motor 10 is capable of motoring and gener- 3. a steering system (not shown); ating simultaneously, even with a single rotor. 20 4. a braking system (not shown); and 5. a drive system 106. 18. Design permits monitoring while running [0080] The chassis 102, surface engaging means 104, [0073] The configuration motor 10 configuration also the steering system and the braking system all operate allows monitoring of stator bar temperature and open cir- 25 in accordance with known principles. Any suitable com- cuit voltage while the machine is running, by measuring bination of known features from the prior art can be used the resistance of a bar 28 while it is open circuited. with the BEV 100 and, as such, are not described here in further detail. 19. Uses low-resistance busbars and conductors. [0081] The drive system 106 includes: 30 [0074] The motor’s power supply bus bars 48 and the a. Battery system 200; stator’s inner circle busbar 46 can be very large, elimi- b. Battery Busbars 300; nating the wasted power losses and associated weight c. Isolators 400; which conventional end turns incur, and which would oth- d. Motor 500; and erwise make a ULV 20kA machine highly inefficient. 35 e. Switching 600.

20. No laminations, efficient flux paths. [0082] The operation of these component parts of the BEV 100 is set out below in further detail. [0075] Unlike conventional brushless motors, arma- ture reaction does not demagnetise the laminated silicon 40 a. Battery System 200 steel pole shoes, as there are no pole shoes. The arma- ture currents can only attempt to demagnetise the neo- [0083] The battery system 200 is divided into two dymium magnets; any saturation of the steel return flux groups: path has little effect on the motor’s torque. Thus very high currents can be used. 45 i. main battery 202; and ii. auxiliary batteries 204. 21. Very high efficiency and power to weight ratio [0084] The main battery 202 is made up of a plurality [0076] The motor 10 may be built light in weight, since of batteries 51 located around the circumference of the there is no iron in the stator 22, and because the current 50 motor 500, in the manner shown in Figure 14, in order to density used in the copper is over five times higher than minimise busbar resistive losses. The main battery 202 conventional machines, due to the lack of insulation on operates in an analogous manner to that of the DC power the winding, and the improved cooling of the winding source 50 shown in Figure 13 and includes a plurality of bars. The motor 10 advantageously gives the highest single cell batteries B1 to B4 Each battery 51 powers a power to weight possible, which has applications in many 55 sector 52 of the motor 500, rather than being connected areas such as spacecraft, aircraft and lightweight electric to a common bus. This minimises the fault level, and vehicles. increases the fault tolerance and redundancy. [0085] The main battery 202, power electronics, con-

7 13 EP 3 257 138 B1 14 trol system and motor 500 are preferably fitted to the b. Battery Busbars 300 vehicle 100 in the engine bay, as a complete assembly, factory assembled and tested. This ensures the integrity [0093] An array of eight main batteries 202 will be used, of the high current joints. Fitting such a complete motor for example. That is, 8 x 1000Ah. Since the main cells assembly into a vehicle minimises the adaptation of con- 5 are not interconnected, they do not need to be at the ventional assembly plants to the production of BEVs. same voltage, state of charge, or cycle life. The battery [0086] The arrangement of the batteries 51 of the main busbars 300 will be as short as possible (typically only battery 202 around the motor 500 in a star configuration 100mm long, and preferably made of copper or alumin- ensures the system losses are minimised. It also ensures ium). the busbars 300 operate in an analogous manner the highest reliability, since the long conductors to the 10 to that of the busbars 48. auxiliary batteries 204 in the rear of the vehicle are not critical for the vehicle’s operation, only to a small per- c. Isolators 400 centage of its range. [0087] It is then possible to replace the entire ’engine’ [0094] As the maximum system voltage is the voltage of a convention vehicle with the motor 500 in a similar 15 of one cell, which is around 3.4V for LiFePO4, isolation manner. The engine 500 can be shipped on pallets, lifted to prevent electric shock is not required. Isolation be- with an engine crane, for replacement by conventional tween the battery 202 and the motor 500 is preferably garage mechanics. The ’engine’ 500 advantageously performed by the same FET power transistors that are weighs a similar amount to the ICE it replaces, ensuring used to control the current flowing in to the windings. No the vehicle’s 100 handling and chassis need not be mod- 20 separate full current battery isolator is needed. Isolation ified, and the crash testing not need to be repeated. The is preferably by electronic means, cutting gate power to engineer’s certificate would be easier to obtain. the transistors. This ensures there is no means for gen- [0088] The auxiliary batteries 204 are preferably locat- erating torque which could cause the motor to rotate, and ed at a plurality of convenient locations around the vehicle allows mechanical locking of the rotor if needed for iso- 100 such as: 25 lation. [0095] A ULV BEV 100 requires no high voltage safety i. under the tray for a ute; systems to detect chassis faults, or to automatically iso- ii. under the back seat; late the battery in the event of this or other kinds of faults, iii. in place of the fuel tank; or vehicle accident. This reduces the cost of the system, iv. in the boot, and 30 and eliminates the need for any compliance testing. In v. even in a trailer. future, it is expected the regulations will increase the amount of safety systems needed in BEVs. Where such [0089] The auxiliary batteries 204 may be different safety systems relate to HV batteries, these can be elim- chemistries and voltage to the main battery 202. Their inated in a ULV system. function is to transfer charge across to the main battery 35 [0096] A ULV system requires no HV contactor and no 202, as needed or required. The charge transfer may be HV isolator. Instead, the FET transistors can be turned regulated by DC to DC converter, in order to limit the off to provide isolation. losses in the cables. The auxiliary batteries 204 may be user replaceable, or swappable. d. Motor 500 [0090] Eight to twelve batteries preferably make up the 40 main battery 202. These are preferably selected for large [0097] The motor 500 preferably includes all of the fea- number of cycles, and higher power, being too heavy for tures of the motor 10 and like part are referenced with user swapping. The whole ’engine’ assembly would then like numbers. Alternatively, the motor 500 is any other weigh about 380kg, comparable to a conventional long electric motor configured to be driven by the main battery engine, which is the ICE / transmission / battery 45 202 having a plurality of cells connected in parallel. / / water pump. As with all BEVs, an electric [0098] The motor 500 is preferably fitted with separate vacuum pump for the brake , electric motor driven terminal connections for the busbars 48, say eight, air conditioner, and electric heater would be required. spaced around its body. Each of the terminals would pro- [0091] By wiring all cells in parallel, weaker cells are vide power to separate bar sectors 52, thus providing not forced into reverse polarity, and the need for cell mon- 50 redundancy. It would be possible to run with less than all itoring is obviated. the bars and sectors energised; any combination is pos- [0092] With all cells in parallel, all cell voltages must sible. be the same, so even if the cells have different temper- [0099] In an alternative embodiment, the motor 500 is: atures and age, they cannot be forced into reverse po- larity by the other cells. 55 (i) a multiple LV motor mechanically coupled on same or coupled shafts by gears or similar means; (ii) a motor similar to the motor 10 where the stator was made from a PCB or a low-inductance winding

8 15 EP 3 257 138 B1 16

rather than a single slotted sheet; e. Switching 600 (iii) a motor similar to the motor 10 where the stator was made in a single segment; [0107] Commutation strategy and bar switching is con- (iv) a motor similar to the motor 10 where it was water trolled by the circuit 30 set out in Figure 7a to 7c. Control cooled or the whole motor ran in a contained fluid 5 strategies for the switching of the bars 28, including the rather than air; timing, phase angle and enabling of the bar 28, would be (v) a homopolar motor with liquid metal or brushes; or done to achieve either maximum torque for high accel- (vi) a heteropolar with copper windings, with or with- eration, or maximum efficiency for longest range. Bars out iron laminations or iron powder. 28, sectors 52 and whole discs in multi disc stator motors 10 500 could be disabled to provide higher efficiency in the Improved Range Estimation remaining bars 28. [0108] The switching is preferably done by microcon- [0100] Running one battery 202 flat, then the next, and trollers on circuit boards mounted around the periphery so on, would allow measurement of the amount of charge of the machine 500. and run time available, therefore allowing an improved 15 range estimation or ’fuel gauge’ for the vehicle 100. Im- Improved Vehicle Range proved range estimation relieves range anxiety, provid- ing a marketable benefit of the BEV 100. The improved [0109] The following factors are expected to improve range calculation allows an accurate fuel gauge, so the the vehicle’s range for a given weight of cells: user would not need to keep some 20 or 30% of the range 20 in reserve, effectively wasting all the resources needed a. 30% improvement in the perceived usable range, to provide that range: capital cost, vehicle weight, battery due to the reduction in range uncertainty ("range anx- replacement costs and so on. Simply by providing an iety"), permissible by staged cell discharge; and by improved fuel gauge, and km remaining estimate, the eliminating any sensitivity to cell failures, unlike a vehicle’s actual usable range can be increased by this 25 series strung battery. Battery capacity can be esti- ’range anxiety factor’. mated by simply measuring the discharge time for one battery, then multiplying the time for the number Very low freewheeling power loss: of remaining batteries. A complex and inaccurate model of the electrochemical cells is not required. [0101] Since there is no ferromagnetic stator, there is 30 b. 20% improvement in actual physical range, by no cogging, so freewheeling down hill would incur no elimination of the BMS, so that each cell can be run hysteresis motor losses, reduced drag. There is no need over its full design capacity, from optimal charge volt- for a clutch between the wheels and the motor. age, to its desired DOD, rather than the overall ca- [0102] A further advantage is that each individual cop- pacity of the battery being determined by just the per bar can be tested to determine its health. With a con- 35 weakest cell’s limits. Since each battery can be ventional three phase stator, the testing is limited to short, charged individually, by means of its own charger, open and ground fault per winding. Inter-turn shorts can- and discharged individually, by means of its own not be located. winding cluster, its state of charge, age, temperature [0103] In a conventional motor, a single break in the and other factors do not make any difference to the copper of any one winding renders that winding inoper- 40 performance of the rest of the system; each battery ative, and usually results in machine failure due to the can contribute all it can. significant reduction in available torque. With this motor, c. A further improvement is advantageously gained any failure of a single bar has a negligible effect on the due to elimination of any voltage conversion: there motor’s performance. are no inductors and no voltage conversion between [0104] This motor 500 facilitates automatic diagnostic 45 the battery and the winding. tests (which can be run while the motor is running) on d. A further improvement due to the stator windings individual bars and their half bridges to check for all the having no hysteresis or iron losses. typical failure modes of a motor. Tests can include open, e. An efficiency improvement due to the use of ultra short, ground fault, turn to turn shorts, open and shorted low on resistance FETs instead of conventional IG- transistors. These tests are impossible on a conventional 50 BTs. wound copper motor, since the winding turns are not in- f. An efficiency improvement due to shorter power dividually accessible. busses between the battery and the motor. [0105] Bar temperature can be also monitored, since g. An efficiency improvement due to elimination of the bar is thermally coupled to the PCB, and temperature isolator and contactor switch losses. sensing may be provided on the board. 55 [0106] Bar torque contribution from individual bars sim- Integrated 12 V Supply ilarly can be tested. [0110] Since the sectors 52 are separate mechanically

9 17 EP 3 257 138 B1 18 and electrically, with one cell per sector it is possible to ventional photolithographic means. Miniaturization of charge cells individually, yet externally to the engine, use motors based on this design is easier since the stator is them as a series string. Therefore, a set of 3.4V LiFePO4 planar. This leads to application in consumer electronics, batteries could be externally used as a 12V battery, yet such as vibrator motors in phones, to camera focussing each cell being charged or discharged by the motors sec- 5 motors. Biomedical applications requiring a fault tolerant, tor. This allows cell balancing and voltage conversion miniature motor for heart replacement. with no losses: there is no voltage step up. Conventional [0122] As with other axial flux machines, the architec- 12V vehicle systems could be used. ture lends itself to expandability, by addition of stator [0111] A 12V power supply integrated with the ’engine’ modules. Since this motor has such thin stator, however, batteries, ensures 12V is available without requiring any 10 comparatively many more stators can be axially stacked 600V to 12V buck converter, nor any dedicated before shaft flex becomes a design problem. 12V charger. [0123] In a series connected battery, each cell contrib- utes two conductor joints to the circuit. Each joint has Eddy Current Braking resistive losses, which increase as the joint ages. In ad- 15 dition, the probability of joint failure also increases with [0112] Another advantage of the motor 500 is that the age. In a conventional 600V battery of LiFePO4 cells, uninsulated windings allow great extraction of heat, mak- this means around 800 joints. Failure of any single one ing eddy current braking practical. This can allow the mo- of these joints results in failure of the whole battery. Fail- tor to act as a true antilock brake. ure in one joint in a parallel connected battery leads to [0113] In one embodiment, the bars 28 are curved. 20 loss of only a single cell. Curving the bars 28 allows for differential expansion be- tween adjacent bars, due to differing temperatures, with- Power Generation out mechanically stressing the joints or bars. [0124] In one embodiment, the motor 10 is modified Battery Construction 25 for power generation. Such a machine 10 could also be used for power generation, such as wind or hydro appli- [0114] Battery construction is simplified, particularly cations, where a parallel connected battery provides ad- with cylindrical cells, since only two end plates are need- vantages of elimination of the need for any battery man- ed, and these can form the battery casing as well as agement system. function as the connecting busbars. Since the battery 30 [0125] Many modifications will be apparent to those voltage is so low, very low cost and simple insulation is skilled in the art without departing from the scope of the needed on the battery or conductors. Oxide layers, thin present invention. non-conducting films and paints can be sufficient as in- sulators. List of Parts [0115] The risk of fire caused by short circuit is greatly 35 reduced, even in the presence of flammable fuels, since [0126] an ULV battery will not spark nor sustain an arc. [0116] The cells may be divided up into smaller batter- 10 Motor ies, since here is no requirement for sectors to be any 12 Rotor particular size to form a circuit, the minimum being two 40 14 Rotor disc bars. Cells of different size may be connected in the one 16 Magnet battery. This is not possible in any other battery. 18 Outer circumferential section of rotor disc [0117] Cells of differing age, temperature, type, casing 20 Shaft and number of cycles can be used in the one battery, 22 Stator provided they are near enough to the battery terminal 45 24 Stator disc voltage so that the initial charge or discharge they receive 26 Slot or give to the pack is within their rating. 28 Electrically conductive bar [0118] The use of this motor 500 practically allows the 30 Driver switch possibility of swapping only part of the application’s bat- 31 Stator printed circuit board tery. BEVs may be designed such that a discharged aux- 50 32 End of bar iliary battery pack may be replaced, by the user, for a 34a, 34b Rotor end disc charged one. 36a, 36b End plate [0119] Partial battery replacement is not presently pos- 37 Fastener sible with any other battery powered motor. 38 Slot [0120] No electronics per cell is required. Batteries of 55 40 Hub thousands of cells are then feasible. 42 Support member [0121] For micro motors, the motor and entire circuitry 43 Slot can be constructed on the one silicon substrate, by con- 44 Fastener

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46 Busbars for electrically coupling the driver is formed by said bars (28), said bars (28) being pla- switches 30 to the outer ends 32 of respec- nar and extending radially from a common inner con- tive bars 38 of the stator disc 24 ducting ring, 48 Busbars 48 for coupling the driver switches wherein a terminal voltage of said machine is equal 30 to a DC power source 5 to the voltage of one electrochemical cell, 48a Positive busbar wherein the power of said machine is at least 1kW. 48b Negative busbar 50 DC power source 2. The motor (10) claimed in claim 1, wherein said 51 Battery switches (30) include multiple transistor half bridge 52 Sector 10 switches (54), each one of said half bridge switches 54 Half bridge (54) connecting to separate points of the stator wind- 56 Slots ing, where said half bridge transistor switches (54) 58 Driver transistor function to provide commutation switching and to 60 Holes regulate current in said stator winding so as to gen- 62 Gate drive supply isolator 15 erate a torque on the rotor (12) and thereby cause said axial rotation of the shaft (20). 100 Battery powered electric vehicle 102 Chassis 3. The motor (10) claimed in claim 2, wherein, each of 104 Surface engaging means one said at least stator winding comprises one half 106 Drive system 20 of one turn only, such that, in use, two of said half bridges (54) are activated, one high side transistor 200 Battery system (58) on in one half bridge (54) and one low side tran- 202 Main battery sistor (58) on in one other half bridge (54), in order 204 Auxiliary battery to complete a circuit to form a one turn winding. 25 300 Battery bus 4. The motor claimed in any one of claims 1 to 3, where- in said at least one stator winding includes a plurality 400 Isolators of electrically independent sectors (52).

500 Motor 30 5. The motor claimed in any one of claims 1 to 4, further comprising an electronic controller (30) for each at 600 Switching least one stator winding integrated with said stator winding by a sandwich construction, wherein said 700 Battery monitoring system controller (30) comprises one or more printed circuit 35 boards (PCBs) and two conductive plates function- ing as DC busbars (46), wherein said PCBs are sub- Claims stantially enclosed at least on each axial face by said busbars. 1. A permanent magnet DC electromagnetic heteropo- lar motor (10), including: 40 6. The motor claimed in claim 5, wherein said DC bus bars (46) electrically couple the switches (30) to out- (a) at least one permanent magnet rotor (12); er ends (32) of respective ones of the bars (28) , (b) a shaft (20) in mechanical communication wherein said bus bars (46) function as heat sinks for with the rotor (12) such that axial rotation of the said stator windings, and/or wherein said bus bars rotor (12) causes axial rotation of the shaft (20); 45 (46) are cooled by the flow of exhaust air ejected (c) a stator (22) including at least one stator radially from an air gap between the stator (22) and winding; and the rotor (12) by the motion of said rotor (12). (d) a plurality of switches (30), each functioning to provide commutation switching for the stator 7. The motor (10) claimed in any one of claims 1 to 6, (22) so as to generate a torque on the rotor (12) 50 wherein the stator (22) is ironless. and thereby cause said axial rotation of the shaft (20), 8. The motor (10) claimed in any one of claims 1 to 7, wherein said driver switches (30) are electrically cou- wherein the stator (22) includes a planar stator disc pled to radial outer ends (32) of the elongate bars (24) having circumferentially distributed and radially 55 (28) of the stator (22) and configured to generate directed slots (26) therein that define corresponding currents that flow along the elongate bars (28) in radially directed elongate electrically conductive alternating radial directions so as to generate a bars (28), wherein said at least one stator winding torque on the rotor (12) and thereby cause axial ro-

11 21 EP 3 257 138 B1 22

tation of the shaft (20). ursachen,

9. The motor (10) claimed in any one of claims 1 to 8, wobei der Stator (22) eine planare Statorscheibe including rotor end discs (34a, 34b) coupled to the (24) mit auf dem Umfang verteilten und radial aus- shaft (20) bookending the rotor (12) and the stator 5 gerichteten Schlitzen (26) darin einschließt, die ent- (22) therebetween. sprechende radial ausgerichtete längliche elektrisch leitende Stangen (28) definieren, wobei die mindes- 10. The motor (10) claimed in claim 9, wherein the rotor tens eine Statorwicklung durch die Stangen (28) ge- end discs (34a, 34b) form a return path for flux gen- bildet ist, wobei die Stangen (28) planar sind und erated by the rotor (12) and are electrically conduc- 10 sich radial von einem gemeinsamen inneren Leiten- tive. den Ring erstrecken, wobei eine Klemmspannung der Maschine gleich 11. The motor (10) claimed in any one of claims 1 to 10, der Spannung einer elektrochemischen Zelle ist, wherein an outer circumferential section of a rotor wobei die Leistung der Maschine mindestens 1 kW disc (14) of the rotor (12) includes a plurality of slots 15 beträgt. (38) shaped to receive and seat therein respective magnets (16). 2. Motor (10) nach Anspruch 1, wobei die Schalter (30) zahlreiche Transistorhalbbrückenschalter (54) ein- 12. The motor (10) claimed in claim 11, wherein the rotor schließen, wobei jeder der Halbbrückenschalter (54) disc (14) includes a central hub (40) for receiving the 20 mit verschiedenen Punkten der Statorwicklung ver- shaft (20) therethrough and a plurality of support bunden ist, wo die Halbbrückentransistorschalter members (42) extending radially between the hub (54) dazu dienen, eine Kommutationsschaltung be- (40) and the outer circumferential section to form reitzustellen und Strom in der Statorwicklung zu re- slots (43) for airflow. gulieren, um ein Drehmoment auf dem Rotor (12) zu 25 erzeugen und dadurch die axiale Rotation der Welle 13. The motor (10) claimed in any one of claims 1 to 12, (20) zu verursachen.

wherein a terminal voltage of said motor (10) is 3. Motor (10) nach Anspruch 2, wobei jede der mindes- equal to the voltage of one electrochemical cell, tens einen Statorwicklung nur eine Hälfte einer Dre- and 30 hung umfasst, so dass bei Verwendung zwei der wherein the power of said motor (10) is at least Halbbrücken (54) aktiviert sind, ein Transistor auf 1kW. der oberen Seite (58) auf einer Halbbrücke (54) und ein Transistor auf der unteren Seite (58) auf einer 14. The motor (10) claimed in any one of claims 1 to 13, anderen Halbbrücke (54), um einen Kreislauf zu ver- comprising a plurality of phases, each phase provid- 35 vollständigen und eine Wicklung mit einer Drehung ed by at least one switch (30) of said plurality of zu bilden. switches (30). 4. Motor nach einem der Ansprüche 1 bis 3, wobei die mindestens eine Statorwicklung eine Vielzahl von Patentansprüche 40 elektrisch unabhängigen Sektoren (52) umfasst.

1. Elektromagnetischer mehrpoliger Gleichstrommo- 5. Motor nach einem der Ansprüche 1 bis 4, weiter um- tor mit Permanentmagnet (10), darin eingeschlos- fassend einen elektronischen Regler (30) für jede sen: der mindestens eine Statorwicklung, die mit der Sta- 45 torwicklung durch ein Sandwichkonstruktion inte- (a) mindestens ein Rotor mit Permanentmagnet griert ist, wobei der Regler (30) eine oder mehrere (12); Leiterplatten (PCBs) und zwei leitende Platten um- (b) eine Welle (20) in mechanischer Kommuni- fasst, die als Gleichstromschienen (46) dienen, wo- kation mit dem Rotor (12), so dass die axiale bei die PCBs im Wesentlichen mindestens auf jeder Rotation des Rotors (12) eine axiale Rotation 50 axialen Seite durch die Schienen eingeschlossen der Welle (20) verursacht; sind. (c) ein Stator (22), darin eingeschlossen min- destens eine Statorwicklung; und 6. Motor nach Anspruch 5, wobei die Gleichstrom- (d) eine Vielzahl von Schaltern (30), die jeweils schienen (46) die Schalter (30) mit äußeren Enden dazu dienen, eine Kommutationsschaltung für 55 (32) von Entsprechenden der Stangen (28) elek- den Stator (22) bereitzustellen, um ein Drehmo- trisch koppeln, wobei die Schienen (46) als Wärme- ment auf dem Rotor (12) zu erzeugen und da- senken für die Statorwicklungen dienen, und/oder durch die axiale Rotation der Welle (20) zu ver- wobei die Schienen (46) durch den Fluss von Abluft

12 23 EP 3 257 138 B1 24

gekühlt werden, die radial von einem Luftspalt zwi- (b) un arbre (20) en communication mécanique schen dem Stator (22) und dem Rotor (12) durch die avec le rotor (12) de sorte que la rotation axiale Bewegung des Rotors (12) ausgestoßen wird. du rotor (12) provoque la rotation axiale de l’ar- bre (20) ; 7. Motor (10) nach einem der Ansprüche 1 bis 6, wobei 5 (c) un stator (22) comprenant au moins un en- der Stator (22) einsenfrei ist. roulement de stator ; et (d) une pluralité de commutateurs (30), chacun 8. Motor (10) nach einem der Ansprüche 1 bis 7, wobei fonctionnant pour fournir le changement de die Treiberschalter (30) mit den radialen äußeren commutation pour le stator (22) afin de générer Enden (32) der länglichen Stangen (28) des Stators 10 un couple sur le rotor (12) et ainsi provoquer (22) elektrisch gekoppelt und konfiguriert sind, um ladite rotation axiale de l’arbre (20), Ströme zu erzeugen, die entlang den länglichen Stangen (28) in alternierenden radialen Richtungen dans lequel le stator (22) comprend un disque de fließen, um ein Drehmoment auf dem Rotor (12) zu stator planaire (24) ayant des fentes (26) réparties erzeugen und dabei eine axiale Rotation der Welle 15 de manière circonférentielle et dirigées de manière (20) zu verursachen. radiale à l’intérieur de ce dernier, qui définissent des barres électriquement conductrices (28) correspon- 9. Motor (10) nach einem der Ansprüche 1 bis 8, darin dantes allongées dirigées de manière radiale, dans eingeschlossen Rotorendscheiben (34a, 34b), die lequel ledit au moins un enroulement de stator est mit der Welle (20) gekoppelt sind, wobei der Rotor 20 formé par lesdites barres (28), lesdites barres (28) (12) und der Stator (22) dazwischen umrahmt ist. étant planaires et s’étendant radialement à partir d’une bague conductrice interne commune, 10. Motor (10) nach Anspruch 9, wobei die Rotorend- dans lequel une tension de borne de ladite machine scheiben (34a, 34b) einen Rückweg für den Fluss est égale à la tension d’une pile électrochimique, bilden, der vom Rotor (12) erzeugt wurde, und elek- 25 dans lequel la puissance de ladite machine est d’au trisch leitend sind. moins 1 kW.

11. Motor (10) nach einem der Ansprüche 1 bis 10, wobei 2. Moteur (10) selon la revendication 1, dans lequel der äußere Umfangsabschnitt einer Rotorscheibe lesdits commutateurs (30) comprennent plusieurs (14) des Rotors (12) eine Vielzahl von Schlitzen (38) 30 commutateurs à demi-pont de transistor (54), cha- umfasst, die geformt sind, um entsprechende Mag- cun desdits commutateurs à demi-pont (54) raccor- neten (16) darin aufzunehmen und unterzubringen. dant deux points séparés de l’enroulement de stator, où lesdits commutateurs à demi-pont de transistor 12. Motor (10) nach Anspruch 11, wobei die Motorschei- (54) servent à fournir le changement de commutation be (14) eine zentrale Nabe (40) umfasst, um die Wel- 35 et à réguler le courant dans ledit enroulement de le (20) dadurch aufzunehmen, und eine Vielzahl von stator afin de générer un couple sur le rotor (12) et Stützelementen (42), die sich radial zwischen der provoquer ainsi ladite rotation axiale de l’arbre (20). Nabe (40) und dem äußeren Umfangsabschnitt er- strecken, um Schlitze (43) für den Luftfluss zu bilden. 3. Moteur (10) selon la revendication 2, dans lequel, 40 chacun dudit au moins un enroulement de stator 13. Motor (10) nach einem der Ansprüche 1 bis 12, wobei comprend un demi-tour uniquement, de sorte que, eine Klemmspannung des Motors (10) gleich der à l’usage deux desdits demi-ponts (54) sont activés, Spannung einer elektrochemischen Zelle ist, und un transistor du côté haut (58) mis en marche dans wobei die Leistung des Motors (10) mindestens 1 un demi-pont (54) et un transistor du côté bas (58) kW beträgt. 45 mis en marche dans l’autre demi-pont (54), afin de compléter un circuit pour former un enroulement d’un 14. Motor (10) nach einem der Ansprüche 1 bis 13, um- tour. fassend eine Vielzahl von Phasen, wobei jede Phase durch mindestens einen Schalter (30) der Vielzahl 4. Moteur selon l’une quelconque des revendications von Schaltern (30) bereitgestellt ist. 50 1 à 3, dans lequel ledit au moins un enroulement de stator comprend une pluralité de secteurs électrique- ment indépendants (52). Revendications 5. Moteur selon l’une quelconque des revendications 1. Moteur hétéropolaire électromagnétique à DC (cou- 55 1 à 4, comprenant en outre un organe de commande rant continu) à aimant permanent (10) comprenant : électronique (30) pour chacun d’au moins un enrou- lement de stator intégré avec ledit élément de stator (a) au moins un rotor à aimant permanent (12) ; par une construction en sandwich, dans lequel ledit

13 25 EP 3 257 138 B1 26

organe de commande (30) comprend une ou plu- est égale à la tension d’une pile électrochimique, et sieurs cartes de circuit imprimé (PCB) et deux pla- dans lequel la puissance dudit moteur (10) est d’au ques conductrices servant de barre omnibus DC moins 1 kW. (46), dans lequel lesdites PCB sont sensiblement enfermées au moins sur chaque face axiale par les- 5 14. Moteur (10) selon l’une quelconque des revendica- dites barres omnibus. tions 1 à 13, comprenant une pluralité de phases, chaque phase étant fournie par au moins un com- 6. Moteur selon la revendication 5, dans lequel lesdites mutateur (30) de ladite pluralité de commutateurs barres omnibus DC (46) couplent électriquement les (30). commutateurs (30) aux extrémités externes (32) des 10 barres (28) respectives, dans lequel lesdites barres omnibus (46) servent de dissipateurs de chaleur pour lesdits enroulements de stator, et/ou dans le- quel lesdites barres omnibus (46) sont refroidies par l’écoulement d’air d’échappement éjecté radiale- 15 ment à partir d’un entrefer entre le stator (22) et le rotor (12) par le mouvement dudit rotor (12).

7. Moteur (10) selon l’une quelconque des revendica- tions 1 à 6, dans lequel le stator (22) est sans fer. 20

8. Moteur (10) selon l’une quelconque des revendica- tions 1 à 7, dans lequel lesdits commutateurs de dis- positif d’entraînement (30) sont électriquement cou- plés aux extrémités externes radiales (32) des bar- 25 res (28) allongées du stator (22) et configurés pour générer des courants qui s’écoulent le long des bar- res (28) allongées dans des directions radiales al- ternées afin de générer un couple sur le rotor (12) et provoquer ainsi la rotation axiale de l’arbre (20). 30

9. Moteur (10) selon l’une quelconque des revendica- tions 1 à 8, comprenant des disques d’extrémité de rotor (34a, 34b) couplés à l’arbre (20) serrant le rotor (12) et le stator (22) entre eux. 35

10. Moteur (10) selon la revendication 9, dans lequel les disques d’extrémité de rotor (34a, 34b) forment une trajectoire de retour pour le flux généré par le rotor (12) et sont électriquement conducteurs. 40

11. Moteur (10) selon l’une quelconque des revendica- tions 1 à 10, dans lequel une section circonférentielle externe d’un disque de rotor (14) du rotor (12) com- prend une pluralité de fentes (38) formées pour re- 45 cevoir et y installer des aimants (16) respectifs.

12. Moteur (10) selon la revendication 11, dans lequel le disque de rotor (14) comprend un moyeu central (40) pour recevoir l’arbre (20) à travers ce dernier et 50 une pluralité d’éléments de support (42) s’étendant radialement entre le moyeu (40) et la section circon- férentielle externe afin de former des fentes (43) pour l’écoulement d’air. 55 13. Moteur (10) selon l’une quelconque des revendica- tions 1 à 12, dans lequel une tension de borne dudit moteur (10)

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16 EP 3 257 138 B1

17 EP 3 257 138 B1

18 EP 3 257 138 B1

19 EP 3 257 138 B1

20 EP 3 257 138 B1

21 EP 3 257 138 B1

22 EP 3 257 138 B1

23 EP 3 257 138 B1

24 EP 3 257 138 B1

25 EP 3 257 138 B1

26 EP 3 257 138 B1

27 EP 3 257 138 B1

28 EP 3 257 138 B1

29 EP 3 257 138 B1

30 EP 3 257 138 B1

31 EP 3 257 138 B1

32 EP 3 257 138 B1

33 EP 3 257 138 B1

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• JP 2009153358 A [0009] • US 2006202584 A [0010]

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