AN ELECTRIFYED DRIVE SYSTEM AND DEVICE

Abstract

A drive system (100), comprising: a first axially flowing rotating electrical machine (410) with a first rotor (420) which is arranged coaxially to a first electrical stator (430); a torque converter (50) comprising a fluidicstator (57), a pump (56), a turbine (58) and a torque converter coupling (52); a selectable one-way coupling (55) coupled to the fluidicstator (57); wherein the first axially flowing rotating electric machine (410) is arranged coaxially to the torque converter (50); wherein the first rotor (420) of the first axially flowing rotating electric machine (410) is coupled to the pump (56) of the torque converter (50); wherein the turbine (58) of the torque converter (50) is rotatably coupled to an output element (59); a second axially flowing rotating electric machine (450) with a second rotor (460) which is arranged coaxially to a second electric stator (465); wherein the second axially flowing rotating electric machine (450) is arranged coaxially to the torque converter (50); wherein the torque converter (50) is arranged axially between the first axially flowing rotating electric machine (410) and the second axially flowing rotating electric machine (450).

Description

TECHNICAL AREA

[0001] This disclosure relates to electrified drive systems for vehicles. BACKGROUND

[0002] Electrified powertrains for vehicles include, for example, battery electric vehicles (BEVs), extended-range electric vehicles (EVs), plug-in hybrid electric vehicles (PEVs), and fuel cell hybrid electric vehicles (FEVs). As experienced professionals know, developing electrified powertrains involves optimizing and balancing traction, weight, pack size, range, drivability, and other factors. Vehicle developers strive for a fast, lightweight, and responsive propulsion system that can be housed in a vehicle and is capable of covering long distances with minimal need for recharging.

[0003] Electric machines convert electrical energy into mechanical work by generating torque. In electric vehicles, including hybrid vehicles, electric motors, such as induction motors and permanent magnet motors, are used to propel the vehicles and, as electric generators, to recover braking energy. Generally, an electric motor consists of a rotor, which rotates during operation, and an electric stator, which is stationary. The rotor can contain a variety of permanent magnets and rotates relative to the stationary electric stator. The rotor is connected to a shaft that also rotates with the rotor. The rotor, including the permanent magnets, is separated from the electric stator by a predetermined air gap. The electric stator contains conductors in the form of wire windings. When electrical energy is supplied through the conductive wire windings, a magnetic field is generated.When electrical energy or power is fed into the conductive windings of the electric stator, the power can be transferred across the air gap by means of a magnetic flux, which generates a torque that acts on the permanent magnets in the rotor. In this way, mechanical power can be transferred to or taken away from the rotating shaft. In an electric vehicle, the rotor thus transmits torque via the rotating shaft, through a gearbox, to the vehicle's drive wheels.

[0004] Two common types of electric motors are radial flux and axial flux motors. In a radial flux motor, the rotor and electrical stator are typically arranged in a concentric or nested configuration, so that when the electrical stator is excited, a magnetic flux is generated that extends radially from the electrical stator to the rotor. Therefore, the conductive windings in the electrical stator are typically arranged perpendicular to an axis of rotation, generating a magnetic field that is oriented radially to the axis of rotation (along the shaft). In an axial flux motor, the electrically conductive wire windings in the electrical stator generate a magnetic field parallel to the axis of rotation, so that the magnetic flux is parallel to the axis of rotation (parallel to the shaft).In certain applications, axial flux motors are desirable because they are relatively lightweight, produce higher power, and are compact compared to radial flux motors.

[0005] DE 10 2019 114 902 A1 describes a powertrain for a vehicle. The powertrain includes a housing, a motor-generator unit, a torque converter, a first and a second shaft, a first and a second gear set, and a torque transmission mechanism. The motor-generator unit includes an output element. The torque converter comprises a pump and a turbine. The pump is connected to the output element of the motor-generator unit for common rotation. The first shaft is rotatably supported by the powertrain housing and is connected to the turbine of the torque converter for common rotation. The second shaft is rotatably mounted on the powertrain housing and is arranged parallel to the first shaft. An output gear is connected to the second shaft for common rotation.

[0006] DE 10 2019 115 839 A1 describes slotted permanent magnets (PM) for electric machines, motor-generator units with slotted PMs, methods for manufacturing / using slotted PMs and motor vehicles equipped with an electric traction motor with slotted PMs.

[0007] DE 10 2019 109 910 A1 describes a brushless electric motor used in an electric starter for an internal combustion engine. The electric motor includes a motor housing with a first bearing, a motor end cap with a second bearing, a multi-phase stator assembly, and a rotor assembly with a rotor shaft.

[0008] DE 10 2019 109 907 A1 describes a brushless electric starter assembly for an internal combustion engine.

[0009] DE 10 2021 102 807 A1 describes electric motors and refers in particular to slot openings of the stator cores of electric motors.

[0010] There is a need for an electrified drive system that maximizes power density, is easy to package, and improves drivability. DESCRIPTION

[0011] An electrified powertrain system is described that maximizes power density, is easy to package, and improves drivability. According to the invention, it comprises a drive system with the features of claim 1.

[0012] One aspect of the revelation is that the output element coupled to the turbine of the torque converter is rotatably connected to a drive train.

[0013] Another aspect of the revelation is that the torque converter clutch is a normally closed clutch, with the torque converter clutch being controlled into an open state during a starting maneuver.

[0014] Another aspect of the disclosure includes the axially flowing rotating electric machine, which is a multiphase brushless permanent magnet rotating electric machine.

[0015] Another aspect of the revelation includes the fact that the first rotor consists of a multitude of radially aligned permanent magnets attached to a disk-shaped backplate.

[0016] Another aspect of the disclosure includes that the first electrical stator is a disk-shaped device with a plurality of radially aligned posts, each of the posts having an electrically conductive winding.

[0017] Another aspect of the disclosure includes the first rotor with a plurality of radially aligned permanent magnets attached to a disk-shaped backplate. The first electric stator is a disk-shaped device with multiple electrically conductive windings, and the multiple radially aligned permanent magnets are arranged in an axial alignment alongside the multiple radially aligned electrically conductive windings and separated by an air gap. Another aspect of the disclosure includes the torque converter coupling, which is either a jaw coupling, a preloaded friction coupling, or an electromagnetic coupling.

[0018] Another aspect of the disclosure includes a second rotor arranged coaxially with the first rotor and the first electrical stator, wherein the electrical stator is arranged between the first and the second rotor and wherein the first rotor is coupled to the second rotor via a shaft.

[0019] Another aspect of the disclosure includes that the first rotor consists of a first plurality of radially aligned permanent magnets attached to a first disk-shaped backplate, the second rotor comprising a second plurality of radially aligned permanent magnets attached to a second disk-shaped backplate, the first electrical stator being a disk-shaped device with a plurality of electrically conductive windings, the first plurality of radially aligned permanent magnets being arranged adjacent to a first side of the plurality of radially aligned electrically conductive windings in an axial orientation and being separated by a first air gap.and wherein the second plurality of radially oriented permanent magnets are arranged adjacent to a second side of a plurality of radially oriented electrically conductive windings in the axial orientation and are separated by a second air gap.

[0020] Another aspect of the disclosure includes a second electric stator arranged coaxially with the first rotor and the first electric stator, the first rotor being arranged between the first and the second electric stator.

[0021] Another aspect of the disclosure includes that the first rotor is a first plurality of radially aligned permanent magnets attached to a first side of a disk-shaped backplate, the first rotor includes a second plurality of radially aligned permanent magnets attached to a second side of the disk-shaped backplate, the first electrical stator comprises a disk-shaped device with a first plurality of electrically conductive windings, the first plurality of radially aligned permanent magnets being arranged adjacent to a first side of the first plurality of electrically conductive windings in an axial orientation and separated by a first air gap.and wherein the second parallel of radially oriented permanent magnets is arranged adjacent to a second side of the first plurality of electrically conductive windings in the axial orientation and is separated by a second air gap.

[0022] Another aspect of the disclosure includes a drive system comprising a first axial-flow rotating electric machine and a second axial-flow rotating electric machine arranged coaxially with a torque converter. The first axial-flow rotating electric machine has a first rotor arranged coaxially with a first electric stator. The second axial-flow rotating electric machine has a second rotor arranged coaxially with a second electric stator. The torque converter comprises a fluid stator, a pump, a turbine, and a torque converter coupling.The first and the second axially flowing rotating electric machine are arranged coaxially with the torque converter, wherein the first rotor and the second rotor of the first axially flowing rotating electric machine are coupled to the pump of the torque converter and wherein the turbine of the torque converter is rotatably coupled to an output element.

[0023] Another aspect of the disclosure includes a selectable one-way coupling that is coupled between the fluidicstator and a mechanical mass element.

[0024] Another aspect of the revelation is that the torque converter clutch is a normally closed clutch, with the torque converter clutch being controlled into an open state during a starting maneuver.

[0025] Another aspect of the disclosure includes that the first electric stator is a first disk-shaped device with a first plurality of radially oriented electrically conductive windings, and the first rotor comprises a first plurality of radially oriented permanent magnets attached to a first disk-shaped backplate. The second electric stator comprises a second disk-shaped device with a second plurality of radially oriented electrically conductive windings; and the second rotor comprises a second plurality of radially oriented permanent magnets attached to a second disk-shaped backplate.The first plurality of radially aligned permanent magnets is arranged in an axial alignment next to the first plurality of radially aligned electrically conductive windings and is separated by a first air gap, and the second plurality of radially aligned permanent magnets is arranged in an axial alignment next to the second plurality of radially aligned electrically conductive windings and is separated by a second air gap.

[0026] Another aspect of the disclosure includes a drive system comprising a first axially flowing rotating electric machine, a second axially flowing rotating electric machine, a first torque converter, and a second torque converter. The first axially flowing rotating electric machine, the second axially flowing rotating electric machine, the first torque converter, and the second torque converter are arranged coaxially. The first axially flowing rotating electric machine comprises a first rotor arranged coaxially with a first electric stator, and the second axially flowing rotating electric machine comprises a second rotor arranged coaxially with a second electric stator. The first torque converter comprises a first fluid stator, a first pump, a first turbine, and a first torque converter coupling.The second torque converter comprises a second fluidicstator, a second pump, a second turbine, and a second torque converter coupling. The first rotor of the first rotating axial-flux electric machine is connected to the first pump of the first torque converter, and the second rotor of the second rotating axial-flux electric machine is connected to the second pump of the second torque converter. The first turbine of the first torque converter is rotatably connected to a first output element, and the second turbine of the second torque converter is rotatably connected to a second output element.

[0027] Another aspect of the disclosure includes that the first electric stator is a first disk-shaped device with a first plurality of radially aligned, electrically conductive windings. The first rotor comprises a first plurality of radially aligned permanent magnets attached to a first disk-shaped backplate, and the second electric stator comprises a second disk-shaped device with a second plurality of radially aligned, electrically conductive windings.

[0028] The second rotor comprises a second plurality of radially aligned permanent magnets attached to a second disk-shaped backplate. The first plurality of radially aligned permanent magnets is arranged axially alongside the first plurality of radially aligned electrically conductive windings and separated by a first air gap. The second plurality of radially aligned permanent magnets is arranged axially alongside the second plurality of radially aligned electrically conductive windings and separated by a second air gap.

[0029] The above features and advantages, as well as other features and advantages of the present teaching, are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the present teaching as defined in the attached claims, in conjunction with the attached drawings. BRIEF DESCRIPTION OF THE FIGURES

[0030] One or more embodiments are now described by way of example with reference to the accompanying figures, in which: Fig. Figure 1 schematically shows a drive system for an electrified drive train comprising an embodiment of a rotating axial flux electric machine coupled to a torque converter as described in the disclosure. Fig. Figure 2 schematically shows elements of the embodiment of the rotating electrical machine with axial flow, which, with reference to Fig. 1 is described, in accordance with the revelation. Fig. Figure 3 schematically shows a drive system for an electrified drive train, comprising a further embodiment of a rotating axial flux electric machine coupled with a torque converter as described in the disclosure. Fig. Figure 4 schematically shows elements of the embodiment of the rotating electrical machine with axial flow, which, with reference to Fig. 3 is described, in accordance with the revelation. Fig. Figure 5 schematically shows a drive system for an electrified drive train with a further embodiment of a rotating axial flux electric machine coupled to a torque converter, in accordance with the disclosure. Fig. Figure 6 schematically shows elements of the embodiment of the rotating electrical machine with axial flow, which, with reference to Fig. 5 is described, in accordance with the revelation. Fig. Figure 7 schematically shows a drive system for an electrified drive train with a further embodiment of a rotating axial flux electric machine coupled to a torque converter, in accordance with the disclosure. Fig. Figure 8 schematically shows a drive system for an electrified drive train, comprising a further embodiment of a rotating axial flux electric machine coupled with a torque converter as described in the disclosure.

[0031] The accompanying figures are not necessarily to scale and may represent a somewhat simplified depiction of various features of the present disclosure as disclosed herein, including, for example, certain dimensions, orientations, positions, and shapes. Details associated with such features are partly determined by the intended application and operating environment. DETAILED DESCRIPTION

[0032] Referring to the figures, the illustrations of which serve to depict certain exemplary embodiments and not to limit them, the Fig. 1 and Fig. Figure 2 schematically depicts elements of an embodiment of a drive system 100, comprising a rotating axial-flux electric machine 10 coupled to a drive train 60 via a novel torque converter 50 and controlled by a control unit 70. Identical numerals throughout the description refer to identical elements. The description is given in relation to an axial orientation with axial reference line 15 and radial reference line 16. An axial-flux electric rotary machine is a type of electric motor design in which the gap between the rotor and the electric stator, and thus the direction of the magnetic flux between the two, is aligned parallel to the axis of rotation. In one embodiment, and as described herein, the axial-flux electric machine 10 is configured as a brushless permanent magnet direct current (DC) motor.In one embodiment, the drive system can comprise an internal combustion engine coupled to the axially rotating electric machine 10 and connected to the drive train 60 via the torque converter 50.

[0033] In one embodiment, the drive system 100 is arranged on a vehicle, and the drive train 60 terminates at one or more vehicle wheels to generate tractive force. The vehicle may be a mobile platform in the form of a commercial vehicle, an industrial vehicle, an agricultural vehicle, a passenger car, an aircraft, a watercraft, a train, an all-terrain vehicle, a people carrier, a robot, and the like, but is not limited to such forms to fulfill the purposes of this disclosure.

[0034] In one embodiment, the drive train 60 comprises a rigid or continuously variable transmission connected to the vehicle wheels via a drive shaft, transaxle, or differential. In another embodiment, the drive system 100 is stationary, and the drive train 60 terminates at an actuator, for example, a fluid pump.

[0035] The electric axial flux rotary machine 10 is a multiphase high-voltage electric motor / generator configured to convert stored electrical energy into mechanical energy and vice versa, which can be stored in a high-voltage energy storage device (battery) 90. The battery 90 can be a high-voltage energy storage device, such as a multi-cell lithium-ion device, an ultracapacitor, or any other device without limitation. Monitored parameters relating to the battery 90 may include the state of charge (SOC), temperature, and others. In one embodiment, the battery 90 can be electrically connected to a remote power source located outside the vehicle via a vehicle-integrated battery charger (not shown) to charge it while the vehicle is stationary.The battery 90 is electrically connected to an inverter module 80 via a high-voltage direct current bus in order to transmit high-voltage direct current electrical power via three-phase conductors to the rotating electrical machine 10 with axial flow in response to control signals from the control unit 70.

[0036] As in the Fig. 1 and Fig. As shown in Figure 2, this embodiment of the electric axial flux machine 10 comprises a single rotor 20 and a single electric stator 30. The electric stator 30 is electrically connected to the battery 90 via the inverter module 80 and a high-voltage bus. The inverter module 80 is equipped with control circuits that include power transistors, e.g., IGBTs, for converting high-voltage direct current to high-voltage alternating current and vice versa. The inverter module 80 can use pulse-width modulated (PWM) control of the IGBTs to convert stored direct current energy from the battery 90 into alternating current energy to drive the rotating electric machine 10 with axial flux to generate torque.Similarly, the inverter module 80 converts the mechanical power transferred to the rotating axial-flow electric machine 10 into DC electrical power to generate electrical energy that can be stored in the battery 90, also as part of a regenerative braking control strategy. The inverter module 80 receives motor control commands and controls inverter states to provide motor drive and regenerative braking functionality. In one embodiment, a DC / DC converter is electrically connected to the high-voltage bus to power a low-voltage battery via a low-voltage bus. The low-voltage battery is electrically connected to an auxiliary power system to supply low-voltage current to low-voltage systems in the vehicle, such as power windows, HVAC fans, seats, and other equipment.The control unit 70 is functionally connected to the inverter module 80 to control the transfer of electrical energy between the battery 90 and the plurality of radially oriented, electrically conductive windings 32 of the stator 30. The control unit 70 controls the inverter module 80 to sequentially electrically activate the radially oriented, electrically conductive windings 32 to exert a rotating magnetic force on a plurality of permanent magnets 24 attached to the rotor 20 to cause rotation of the rotor 20, or to respond to a torque to decelerate the rotation of the rotor 20.

[0037] The rotor 20 comprises a disk-shaped backplate 22, which is arranged concentrically to and attached to a rotatable shaft element (shaft) 12. The backplate 22 includes a plurality of radially oriented permanent magnets 24, which are arranged near an outer circumference of the backplate 22. The permanent magnets 24 can have alternating polarity. Adjacent pairs of permanent magnets 24 form a channel between them, which can extend radially along a surface of the rotor 20. In this way, the permanent magnets 24 and the channel together can form a plurality of magnetic poles. As is known to those skilled in the art, the number, shape, arrangement, and orientation of the permanent magnets 24 can differ from those shown. The rotor 20 is mounted on the shaft 12 and supported by bearings housed in the stationary frame element 35. The center of the shaft 12 is located on and defines the axial reference line 15.The rotor 20 rotates with the shaft 12 during operation. The electric stator 30 is a disk-shaped device that is concentric with the shaft 12. The electric stator 30 is attached to the stationary frame element 35. The electric stator 30 comprises a plurality of electromagnetic components in the form of radially oriented, electrically conductive windings 32, which are separated from one another to form electromagnetic poles.

[0038] The radially oriented electrically conductive windings 32 and the radially oriented permanent magnets 24 are arranged axially adjacent to the radially oriented electrically conductive windings 32 and separated by an air gap 17. The radially oriented electrically conductive windings 32 are electrically connected to the inverter module 80 in a multiphase arrangement to generate an electromagnetic force that is exerted on the radially oriented permanent magnets 24 to force the rotation of the rotor 20 when it is operated in motor mode to generate torque in traction mode, and to resist the rotation of the rotor 20 when it is operated in reactive mode to generate electrical energy in regenerative mode.The radially oriented, electrically conductive windings 32 can be electrically connected in a three-phase configuration in one embodiment, although the concepts described here are not limited to three-phase. Other phase arrangements, e.g., two-phase, four-phase, etc., can be used.

[0039] The torque converter 50 can be a fluidic torque coupling device arranged coaxially between the axially rotating electric machine 10 and the drive train 60. The torque converter 50 comprises a pump 56 rotatably connected to the shaft 12, a fluidicstator 57, and a turbine 58 rotatably connected to the output element 59, which is rotatably connected to the drive train 60. The torque converter 50 also comprises a controllable torque converter coupling 52 and a selectable one-way clutch (SOWC) 55. The torque converter coupling 52 can be configured as a jaw coupling, a preloaded friction coupling, or an electromagnetic coupling. The torque converter coupling 52 is configured as a normally closed coupling that is controlled to an open state under certain operating conditions, e.g., during a starting maneuver.

[0040] The torque converter 50 provides a fluidic torque coupling between the pump 56 and the turbine 58 when the clutch 52 is deactivated or disengaged, and a mechanical torque coupling between the pump 56 and the turbine 58 when the clutch 52 is engaged. When the clutch 52 is deactivated or disengaged, a speed difference can occur between the pump 56 and the turbine 58 due to the fluidic torque coupling; this is referred to as torque converter clutch slippage. The torque converter clutch slippage can be measured using speed sensors. The SOWC 55 is arranged to selectively couple the fluidicstator 57 to the stationary frame part 35, thus enabling reverse operation when engaged.

[0041] The shaft 12 is connected to the pump 56 of the torque converter 50 in order to transmit the torque to the output element 59, which in one embodiment is connected to a part of the drive train 60.

[0042] The drivetrain 60 includes, for example, a transmission. In one embodiment, the transmission can be arranged in a stepped gear configuration and include one or more differential gear sets and actuable clutches configured to effect torque transmission in one of several fixed gear states over a range of speed ratios between the output element 59 of the torque converter 50 and a drivetrain component. The transmission can be of various configurations and can be an automatic transmission that shifts automatically between the fixed gear states.

[0043] In one embodiment, the drivetrain 60 can comprise a transmission mechanically connected to one or more axles, which in turn are mechanically connected to one or more wheels. The drivetrain transmits the tractive force to a road surface. The transmission of the drivetrain 60 can consist of a front transaxle and half-shafts (not shown) rotatably connecting the output element 59 to one or more wheels. Alternatively, the transmission set can take the form of a rear differential and axles rotatably connecting the output element 59 to one or more of the wheels. Alternatively, the transmission set can consist of a front transaxle connected to a rear drive shaft coupled to a differential that rotatably connects the output element 59 to one or more wheels.Alternatively or additionally, a power take-off gearbox (not shown) can be rotatably connected to the output element 59. The drive system 100 is exemplary, and the concepts described here also apply to other drive systems that are similarly configured.

[0044] In one embodiment, a fluidic system 85 is arranged to supply the torque converter 50 with hydraulic fluid and is also in fluid communication with heat exchanger elements arranged on the axially rotating electric machine 10 and on the inverter module 80. The fluidic system 85 comprises, as non-limiting examples, a fluidic pump, a sump, a cooling element, and associated piping elements and is configured to supply the torque converter 50 with hydraulic fluid and also to dissipate heat from the electric machine 10 and the inverter module 80.

[0045] In the Fig. 3 and Fig. Figure 4 shows a further embodiment of the drive system 200. In this embodiment, the electric axial flux rotary machine 210 comprises a single electric stator 30, which is arranged coaxially with a first rotor 220 and a second rotor 221 and is inserted between them. The first and second rotors 220, 221 are coupled to each other via the shaft 12 and separated from the single electric stator 30 by a first and second air gap 17 and 18, respectively. The radially oriented, electrically conductive windings 32 of the electric stator 30 are electrically connected to the battery 90 via the inverter module 80 and the high-voltage bus. Operation is controlled by the controller 70. The shaft 12 is connected to the pump 56 of the torque converter 50 to transmit the torque to the output element 59, which in one embodiment is connected to the drive train 60.

[0046] The first rotor 220 comprises a first base plate 222 to which a first set or a plurality of radially aligned permanent magnets 224 is attached. The second rotor 221 comprises a second support plate 223 to which a second set or a plurality of radially aligned permanent magnets 225 is attached.

[0047] In the Fig. 5 and Fig. Figure 6 shows a further embodiment of the drive system 300. In this embodiment, the electric axial flux rotary machine 310 comprises a first electric stator 330 and a second electric stator 331, which are arranged coaxially with a rotor 320 located between them. The rotor 320 is coupled to the shaft 12. The first and second electric stators 330 and 331 are separated from the rotor 320 by a first and second air gap 317 and 318, respectively. The shaft 12 is coupled to the pump 56 of the torque converter 50 to transmit the torque to the output element 59, which in one embodiment is coupled to an embodiment of the drive train 60.

[0048] The rotor 320 comprises a disk-shaped carrier plate 322 with a first set or plurality of radially aligned permanent magnets 24 attached to a first side 321, and a second set or plurality of radially aligned permanent magnets 24 attached to a second, opposite side 323 of the carrier plate 322.

[0049] The first electric stator 330 has a first plurality of radially aligned electrically conductive windings 332, and the second electric stator 331 has a second plurality of radially aligned electrically conductive windings 333.

[0050] The first radially oriented, electrically conductive windings 332 of the first electrical stator 330 are electrically connected to the battery 90 via the first inverter module 380 and the high-voltage bus. The second radially oriented, electrically conductive windings 333 of the second electrical stator 331 are electrically connected to the battery 90 via the second inverter module 382 and the high-voltage bus. Operation is controlled by the control unit 70.

[0051] In one embodiment, the first radially oriented electrically conductive windings 332 of the first electrical stator 330 are rotationally aligned with the second radially oriented electrically conductive windings 333 of the second electrical stator 331. This facilitates the maximization of the electromagnetic force exerted on the rotor 320 by the first and second electrical stators 330, 331. In another embodiment, the first radially oriented electrically conductive windings 332 of the first electrical stator 330 are offset by 180 degrees of electrical rotation relative to the second radially oriented electrically conductive windings 333 of the second electrical stator 331. This facilitates the minimization of the ripple caused by the electromagnetic force exerted on the rotor 320 by the first and second electrical stators 330, 331.

[0052] Fig. Figure 7 shows another embodiment of the drive system 400. In this embodiment, a first electric axial flux rotary machine 410 and a second electric axial flux rotary machine 450 are arranged coaxially with the torque converter 50. The first axial flux rotary machine 410 and the second axial flux rotary machine 450 are configured analogously to the configuration of the first axial flux rotary machine 10, which is described with reference to Fig. 1 is described. The shaft 12 is coupled to the pump 56 of the torque converter 50 in order to transmit the torque to the output element 59, which in one embodiment is coupled to an embodiment of the drive train 60.

[0053] The first electric axial-flux rotary machine 410 comprises a first electric stator 430, which is arranged coaxially with a first rotor 420. The first rotor 420 is coupled to the shaft 412. The first electric stator 430 is separated from the first rotor 420 by a first air gap 417. The second electric axial-flux rotary machine 450 comprises a second electric stator 465, which is arranged coaxially with a second rotor 460. The second rotor 460 is also coupled to the shaft 412. The second electric stator 465 is separated from the second rotor 460 by a second air gap 418. The first electric stator 430 is electrically connected to the battery 90 via a first inverter module 480 and a high-voltage bus. The second electric stator 465 is electrically connected to the battery 90 via a second inverter module 482 and a high-voltage bus. The operation is controlled by the control unit 70.

[0054] Fig. Figure 8 shows another embodiment of the drive system 800. In this embodiment, a first axial flux rotary machine 810 and a second axial flux rotary machine 863 are arranged coaxially with a first torque converter 850 and a second torque converter 840, respectively. The first axial flux rotary machine 810 and the second axial flux rotary machine 863 are configured in a manner analogous to the configuration of the first axial flux rotary machine 10, which is described with reference to Fig. 1 is described.

[0055] The first electric axial flux rotary machine 810 comprises a first electric stator 830 arranged coaxially with a first rotor 820, which is coupled to a first shaft 812. The first electric stator 830 is separated from the rotor 820 by a first air gap 816. The first shaft 812 is coupled to a first pump 848 of the first torque converter 840 to transmit torque to a first output element 849, which is coupled to an embodiment of the drive train 870, which in one embodiment may be a half-shaft coupled to a wheel. The first torque converter 840 is analogous to the torque converter 50 and comprises a pump 846, a fluid stator 847, and a turbine 848, which is rotatably coupled to a first output element 849, which is rotatably connected to a first drive train 870.The first torque converter 840 also includes a controllable torque converter clutch 842 and a selectable one-way clutch (SOWC) 845.

[0056] The second electric axial flux rotary machine 863 comprises a second stator 865, which is arranged coaxially with a second rotor 860. The second rotor 860 is coupled to a second shaft 813. The second electric stator 865 is separated from the second rotor 860 by a second air gap 817. The second electric stator 865 is electrically connected to the battery 90 via a second inverter module 882 and a high-voltage bus. Operation is controlled by the control unit 70.

[0057] The second shaft 813 is coupled to a second pump 856 of the second torque converter 850 to transmit the torque to a second output element 859, which is coupled to an embodiment of the drive train 871, which in one embodiment may be a half-shaft coupled to a wheel. The second torque converter 850 is analogous to the torque converter 50 and comprises the second pump 856, the second fluid stator 857, and the second turbine 858, which is rotatably connected to the second output element 859, which is rotatably connected to the second drive train 871. The second torque converter 850 also comprises a controllable torque converter clutch 852 and a selectable one-way clutch (SOWC) 855.

[0058] The terms control unit, control module, module, controller, control unit, processor, and similar terms refer to one or more combinations of application-specific integrated circuits (ASICs), electronic circuits, central processing units (CPUs), such as microprocessors, and associated non-transient memory components in the form of working memory and storage devices (read-only memory, programmable read-only memory, direct access memory, hard disk drive, etc.). The non-transient memory component is capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuits, input / output circuits and devices, signal conditioning and buffer circuits, and other components that one or more processors can access to provide a described functionality.Input / output circuits and devices include analog-to-digital converters and related devices that monitor sensor inputs, either at a preset sampling rate or in response to a triggering event. Software, firmware, programs, instructions, control routines, code, algorithms, and similar terms refer to sets of instructions executable by control devices, including calibrations and lookup tables. Each control device executes control routine(s) to provide the desired functions, including monitoring inputs from measuring instruments and other networked control devices, and executing control and diagnostic routines to manage the operation of actuators. The routines can be executed at regular intervals, for example, every 100 microseconds or 3.125, 6.25, 12.5, 25, and 100 milliseconds during operation.Alternatively, routines can be executed in response to a triggering event. Communication between control units and between control units, actuators, and / or sensors can occur via a direct wired connection, a networked communication bus, a wireless connection, a serial peripheral interface bus, or another communication link. This communication involves the exchange of data signals in various forms, such as electrical signals over a conductive medium, electromagnetic signals over air, optical signals over fiber optics, and so on. Data signals can include sensor inputs, actuator commands, and communication signals between control units.The terms “dynamic” and “dynamic” used here describe steps or processes that are executed in real time and are characterized by the fact that the states of parameters are monitored or otherwise determined and the states of the parameters are updated regularly or periodically during the execution of a routine or between iterations of the execution of the routine.

[0059] The term “system” as used here may refer to one or a combination of mechanical and electrical actuators, sensors, controllers, application-specific integrated circuits (ASICs), combinational logic circuits, software, firmware and / or other components arranged to provide the described functionality.

[0060] The concepts described here relate to the operation of an embodiment of the drive system described here, in which the electric axial flux rotary machine 10 is used to reduce the parameters associated with NVH and to improve the packaging.

[0061] This means that the flux path is much shorter compared to radial flux machines, allowing the motor to be smaller for the same power output, with higher power density and efficiency. Because the flux path in axial flux machines is one-dimensional, grain-oriented electrical steel can be used. The steel facilitates flux flow, resulting in higher efficiency. Furthermore, the short axial length of axial flux motors offers packaging advantages.

[0062] The elements of the electric machine can be built on a flat structure, such as a printed circuit board, with coils and a bearing added.

[0063] Winding the coils can be significantly simpler, as can connecting the coil and core. Because the coils are flat, rectangular copper strips can be used more easily, simplifying the winding of high currents. The rotor weight can potentially be reduced considerably. The rotor-stator gap can be smaller than in a radial flux electric machine because it is not affected by centrifugal forces and can be adjusted after the design phase. Compared to a radial flux electric machine, a shorter magnetic path length can be achieved. Many of the components are flat and can be manufactured without special casting or stamping tools, reducing costs. The magnetic path through the windings is generally straight, allowing the use of grain-oriented electrical steel, which, compared to stainless steels, has, among other advantages, higher permeability and lower core losses.The arrangement of the axially flowing rotating electric machine in the immediate vicinity of the torque converter facilitates and enables the use of transmission fluid as a cooling medium for the axially flowing rotating electric machine.

[0064] The detailed description and the drawings or figures are supporting and descriptive of the present teaching, but the scope of the present teaching is defined exclusively by the claims. While some of the best modes and other embodiments for carrying out the present teaching have been described in detail, various alternative designs and embodiments for carrying out the present teaching are defined in the accompanying claims.

Claims

[1] A drive system (100), comprising: a first axially flowing rotating electrical machine (410) with a first rotor (420) which is arranged coaxially to a first electrical stator (430); a torque converter (50) comprising a fluidicstator (57), a pump (56), a turbine (58) and a torque converter coupling (52); a selectable one-way coupling (55) coupled to the fluidicstator (57); wherein the first axially flowing rotating electric machine (410) is arranged coaxially to the torque converter (50); wherein the first rotor (420) of the first axially flowing rotating electric machine (410) is coupled to the pump (56) of the torque converter (50); wherein the turbine (58) of the torque converter (50) is rotatably coupled to an output element (59); a second axially flowing rotating electric machine (450) with a second rotor (460) which is arranged coaxially to a second electric stator (465); wherein the second axially flowing rotating electric machine (450) is arranged coaxially to the torque converter (50); wherein the torque converter (50) is arranged axially between the first axially flowing rotating electric machine (410) and the second axially flowing rotating electric machine (450). [2] The drive system (100) according to claim 1, wherein the output element (59) coupled to the turbine (58) of the torque converter (50) is rotatably connected to a drive train (60). [3] The drive system (100) according to claim 1, wherein the torque converter clutch (52) comprises a normally closed clutch and wherein the torque converter clutch (52) is controlled to an open state during a starting maneuver. [4] The drive system (100) according to claim 1, wherein the first axially flowing rotating electric machine (410) comprises a multiphase brushless permanent magnet rotating electric machine. [5] The drive system (100) according to claim 1, wherein the first rotor (420) has a plurality of radially aligned permanent magnets (24) attached to a disk-shaped backplate (22). [6] The drive system (100) according to claim 1, wherein the first electric stator (430) comprises a disk-shaped device with a plurality of radially aligned posts, each of the posts having an electrically conductive winding (32). [7] The drive system (100) according to claim 1, wherein the first rotor (420) has several radially aligned permanent magnets (24) which are attached to a disk-shaped back plate (22); wherein the first electrical stator (430) comprises a disk-shaped device with a plurality of electrically conductive windings (32); and wherein the several radially oriented permanent magnets (24) are arranged in an axial orientation next to the several radially oriented electrically conductive windings (32) and are separated by an air gap (417). [8] The drive system (100) according to claim 1, wherein the torque converter coupling (52) comprises either a jaw coupling, a preloaded friction coupling or an electromagnetic coupling.

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