Selectable differential drive for a vehicle

Abstract

A drive system includes a first drive train and a second drive train coupled by a differential assembly. Each drive train includes an electric machine, an output gear, and a clutch assembly that engages and disengages the output gear with a corresponding half shaft. The differential assembly is configured to couple a first half shaft and a second half shaft and connect / disconnect the first output gear and the first half shaft. The differential assembly includes, for example, a side gear, a spider gear set, and an actuator for engaging and disengaging a differential housing with the first output gear. A control system is configured to actuate the clutch assemblies and / or the actuator of the differential assembly to implement one or more drive modes for each drive axle. The control system determines a first drive mode, controls the clutch assemblies and the differential assembly, and controls one or more electric machines. Drive modes include, for example, torque vectoring, full lock, single electric machine, and neutral.

Description

[0001] introduction

[0002] Vehicles using two electric motors and two axle outputs typically align the two motors on the same axis of rotation. For example, the rotor shafts of the two motors can each enter a corresponding gearbox positioned between the two motors. This results in component stacking, making the overall assembly wider and therefore difficult to package in some applications. This can limit, for example, the length of the motor that can be used, which in turn limits the amount of torque and power the motor can provide. Therefore, it would be advantageous to provide a drive unit configuration with a shape that facilitates packaging. It would also be advantageous to provide a drive unit that allows the use of a wider range of motors and associated components.

[0003] Motors and associated gearboxes are typically designed for specific applications. For example, gearboxes are often designed for single-motor drive units or dual-motor drive units, but not both simultaneously. As another example, gearboxes are often designed for a specific orientation and to drive a set number of wheels. Therefore, it is advantageous to provide drive units that can be used in more than one application in more than one drive mode. It is also advantageous to provide drive units that can be used independently or coupled to adapt to changing drive conditions. Summary of the Invention

[0004] In some embodiments, this disclosure relates to a drive system having a center-disconnect differential and two output gears. A first output gear is configured to rotate based on a first motor, and a first half-shaft is configured to rotate based on the first output gear. A second output gear is configured to rotate based on a second motor, and a second half-shaft is configured to rotate based on the second output gear. The center-disconnect differential engages the first half-shaft and is connected to the second half-shaft, and is configured to connect and disconnect the first output gear from the first half-shaft. For illustration, a neutral mode can be achieved when disconnected, and a super-oil-saving (e.g., single-motor) mode can be achieved when engaged. In some embodiments, the system includes a first actuator configured to engage and disengage the first output gear from the differential housing.

[0005] In some implementations, the center-disconnect differential is further configured to connect the first output gear to the housing of the center-disconnect differential. For example, in super fuel-saving mode, the first and second half-shafts are configured to rotate based on the first output gear when the second output gear is disconnected from the second half-shaft.

[0006] In some implementations, the center-disconnect differential is further configured to connect a first output gear to the housing of the center-disconnect differential and a second output gear to a second side gear of the second half-shaft. For example, in a shift mode, the first and second half-shafts are configured to rotate based on the connection of the second output gear to the second side gear.

[0007] In some implementations, the center-disconnect differential is further configured to connect a first output gear to the housing of the center-disconnect differential and a first side gear of the first half-shaft, and a second output gear to a second side gear of the second half-shaft. For example, in locked mode, the first and second output gears produce an increase in torque relative to one or more of the first and second half-shafts.

[0008] In some implementations, the center-disconnect differential is further configured to disengage the first output gear from the center-disconnect differential housing, connect the first output gear to the first half-shaft, and connect the second output gear to a second side gear on the second half-shaft. The first and second output gears generate independent torques with respect to their respective first and second half-shafts. For example, in a torque vectoring mode, the first and second output gears generate independent torques with respect to their respective first and second half-shafts.

[0009] In some embodiments, the system includes a first clutch assembly configured to connect a first output gear to a first half-shaft by transmitting torque from a first output gear to a first half-shaft, a second clutch assembly connecting the first output gear to the first half-shaft, and a second clutch assembly configured to connect a second output gear to a second half-shaft by transmitting torque from a second output gear to a second half-shaft.

[0010] In some embodiments, the system includes a fixed housing, a first bearing disposed between the first output gear and the fixed housing, a second bearing disposed between the second output gear and the fixed housing, and a third bearing disposed between the first output gear and the second output gear.

[0011] In some embodiments, this disclosure relates to a drive system for a vehicle, the drive system including two output gears, two clutch assemblies, and a center-disconnect differential. A first output gear is driven by a first motor, and a second output gear is driven by a second motor. The first clutch assembly is configured to engage and disengage the first output gear from a first half-shaft coupled to a first wheel. The second clutch assembly is configured to engage and disengage the second output gear from a second half-shaft coupled to a second wheel. The center-disconnect differential is configured to engage the first output gear to a first output shaft and to the second half-shaft. In some embodiments, the first and second motors are configured to be independently controlled.

[0012] In some embodiments, the drive system includes control circuitry. In some such embodiments, a first clutch assembly includes a first actuator coupled to the control circuitry, a second clutch assembly includes a second actuator coupled to the control circuitry, and the drive system includes a third actuator coupled to the control circuitry and configured to engage and disengage a first output gear from the differential housing. For illustration, the control circuitry is configured to actuate and deactivate each of the first, second, and third actuators. In some embodiments, the control circuitry is configured to implement a first drive mode in which the first clutch assembly is engaged, the second clutch assembly is engaged, and the center-disengaged differential is disengaged. In some embodiments, the control circuitry is configured to implement a second drive mode in which the first clutch assembly is engaged, the second clutch assembly is engaged, and the center-disengaged differential is engaged. In some embodiments, the control circuitry is configured to implement a third drive mode in which the first clutch assembly is disengaged, the second clutch assembly is disengaged, and the center-disengaged differential is engaged.

[0013] In some embodiments, the center-disconnect differential includes a planetary gear set coupled to a differential housing, a first side gear coupled to a first half-shaft and engaging the planetary gear set, and a second side gear coupled to a second half-shaft and engaging the planetary gear set. In some such embodiments, the center-disconnect differential includes a first thrust washer disposed between the first side gear and a first output gear, and a second thrust washer disposed between the second side gear and a fixed portion of the housing.

[0014] In some embodiments, the drive system includes a first power transmission mechanism configured to couple rotation of a first motor shaft to rotation of a first output shaft and to reduce the rotational rate of the first output shaft relative to the rotational rate of the first motor shaft. In some embodiments, a second power transmission mechanism is configured to couple rotation of a second motor shaft to rotation of a second output shaft and to reduce the rotational rate of the second output shaft relative to the rotational rate of the second motor shaft. The power transmission mechanism may include an intermediate gear that provides the reduction between a corresponding motor gear and an output gear. In an exemplary example, the power transmission mechanism may include a motor gear, an output gear, and any optional intermediate gear, and may be configured to reduce the rotational rate between the motor shaft and the output shaft.

[0015] In some embodiments, this disclosure relates to a method for managing drive modes of a drive shaft. The method includes controlling a first clutch connecting a first output gear and a first half-shaft of the drive shaft; controlling a second clutch connecting a second output gear and a second half-shaft of the drive shaft; controlling a differential configured to engage the first output gear to the first half-shaft and to the second half-shaft; and controlling at least one of a first motor engaged to the first output gear or a second motor engaged to the second output gear. For example, in some embodiments, the first and second half-shafts are connected to each other via side gears, planetary gears, and a differential housing, and a differential actuator is controlled to engage or disengage the housing from the first output gear.

[0016] In some implementations, the method includes determining a torque vectoring distribution mode at the drive shaft. The torque vectoring distribution mode is achieved by: engaging a first clutch connecting a first output gear and a first half-shaft of the drive shaft; engaging a second clutch connecting a second output gear and a second half-shaft of the drive shaft; disengaging a differential configured to connect and disconnect the first and second half-shafts; and independently controlling the rotation of the first and second motors.

[0017] In some implementations, the method includes determining a fully locked drive mode at the drive shaft. The fully locked drive mode is achieved by the following steps: engaging a first clutch, engaging a second clutch, and engaging a differential.

[0018] In some implementations, the method includes determining how to achieve a single-motor drive mode. This single-motor drive mode is achieved by the following steps: disengaging a first clutch, disengaging a second clutch, engaging a differential, and controlling the rotation of the first motor. In some implementations, in neutral mode, the method includes allowing a second motor to rotate freely without power input.

[0019] In some implementations, the method includes determining a neutral drive mode at the drive shaft. The neutral drive mode is achieved by the following steps: disengaging a first clutch, disengaging a second clutch, disengaging a differential, and allowing both the first and second motors to rotate freely without electrical input.

[0020] In some implementations, the method includes determining the drive mode based on at least one of the following: a signal from a speed sensor, an energy consumption metric, input to a user interface, the torque value of a first motor, or the torque value of a second motor. Attached Figure Description

[0021] The present disclosure is described in detail with reference to the following accompanying drawings, which illustrate one or more various embodiments. The drawings are provided for illustrative purposes only and show only typical or exemplary embodiments. These drawings are provided to facilitate understanding of the concepts disclosed herein and should not be considered as limitations on the breadth, scope, or applicability of these concepts. It should be noted that these drawings are not necessarily drawn to scale for clarity and ease of illustration.

[0022] Figure 1 A top view of exemplary components of an electric vehicle according to some embodiments of the present disclosure is shown;

[0023] Figure 2 Three exemplary drive unit configurations according to some embodiments of this disclosure are shown;

[0024] Figure 3 An exemplary arrangement of gears within a gearbox according to some embodiments of the present disclosure is shown;

[0025] Figure 4 A cross-sectional view is shown of an exemplary arrangement of nested drive gears, clutch assemblies and differential assemblies according to some embodiments of the present disclosure;

[0026] Figures 5 to 7 Some embodiments according to this disclosure are shown. Figure 4 Cross-sectional views of exemplary arrangements in different driving modes;

[0027] Figure 8 A cross-sectional view of a drive system with a differential according to some embodiments of the present disclosure is shown;

[0028] Figures 9 to 11 Some embodiments according to this disclosure are shown. Figure 8 Cross-sectional views of exemplary drive systems in different drive modes;

[0029] Figure 12 A perspective sectional view of an exemplary drive system according to some embodiments of the present disclosure is shown;

[0030] Figure 13 A cross-sectional view of a portion of an exemplary drive system with an integrated differential according to some embodiments of the present disclosure is shown;

[0031] Figure 14 A cross-sectional view of a portion of an exemplary drive system with couplings according to some embodiments of the present disclosure is shown;

[0032] Figure 15 A cross-sectional view of a portion of an exemplary drive system with an intermediate differential according to some embodiments of the present disclosure is shown;

[0033] Figure 16 A cross-sectional view of a portion of an exemplary drive system having an intermediate differential and an intermediate clutch according to some embodiments of the present disclosure is shown;

[0034] Figure 17 A cross-sectional view of an exemplary drive system according to some embodiments of the present disclosure is shown;

[0035] Figure 18 A block diagram of an exemplary electric vehicle having a control system for controlling one or more drive units, according to some embodiments of the present disclosure, is shown.

[0036] Figure 19 A flowchart illustrating an exemplary process for managing an electric vehicle drive system according to some embodiments of this disclosure is shown. Detailed Implementation

[0037] This disclosure relates to a motor drive unit architecture with a controllable differential. In some embodiments, the motor drive unit architecture aligns two or more motors on different axles. In some embodiments, this disclosure relates to a drive unit that allows for multiple configurations. For illustration, with reference to four motors, torque vectoring capability, electric vehicle architecture (or a dual-motor drive unit with torque vectoring at the axles relative to a pair of wheels), there may be a large differential at any given time between the amount of power and / or torque available from all four motors and the amount of torque and / or power required to maintain a constant vehicle speed. Furthermore, in cases where constant speed cruising is desired, it is advantageous to use as few motors and powertrains as possible for efficiency, travel, or both. As with many other drive systems, electrical and / or mechanical devices can be used to “close” or otherwise disengage, and associated losses are minimized as much as possible.

[0038] In some cases, dual drive units offer various advantages, including the ability to provide torque vectoring. The dual drive units of this disclosure offer one or more advantages. In some embodiments, the dual drive units of this disclosure can be configured to fit into vehicles that are otherwise too small to accommodate the necessary hardware. This allows for the appropriate encapsulation of a torque vectoring drive unit in a smaller passenger vehicle. In some embodiments, the dual drive units of this disclosure enable the use of relatively large motors to complement high-performance applications employing torque vectoring drive units. This results in even more power being distributed to the vehicle with high-output torque vectoring. In some embodiments, the dual drive units of this disclosure enable the use of longer half-shafts, meaning that more hover travel is possible without compromising vehicle speed. Therefore, off-road applications or modes requiring greater overall hover travel can be used at relatively higher speeds.

[0039] In some embodiments, this disclosure relates to a selective differential gearbox that provides control over travel distance while also providing torque vectoring, neutral differential, open differential, single-motor drive, and differential locking. In some embodiments, the electric drive system may include one or more electric motors configured to achieve torque vectoring (e.g., a dual-motor or quad-motor architecture). For example, it may include a front drive unit (FDU) and a rear drive unit (RDU), and each may include two inverter cores, two motors, and two separate gear sets integrated into a single package.

[0040] Figure 1 A top view of exemplary components of an electric vehicle 100 according to some embodiments of the present disclosure is shown. In some embodiments, the vehicle may include two or more electric motors arranged in one or more drive units. For example, some motor assemblies in the motor assembly may be identical, while some motor assemblies may have different rotational characteristics or shaft rotation directions relative to the motor. As shown, the front drive unit 110 and the rear drive unit 120 are oriented in different ways. The components and orientations of the front drive unit 110 and the rear drive unit 120 may be the same or different to accommodate appropriate shaft rotation and assembly within the vehicle. Figure 1An exploded view of motor assemblies 111, 112, 121, and 122 is also shown. Motor assemblies 111 and 112 are included in the front drive unit 110 (e.g., together with other components such as a differential, intermediate housing, bearings, etc.). Motor assemblies 121 and 122 are included in the rear drive unit 120 (e.g., together with other components such as a differential, intermediate housing, bearings, etc.). The front drive unit 110 and the rear drive unit 120 may each include a differential, an output shaft clutch, or both to control the number of motors used, the number of driven output shafts, the independence of the output shafts, or a combination thereof. For example, the differential and clutch assemblies of this disclosure may be applied to the front wheels, the rear wheels, or both. For illustration, zero, one, or two motors may be used at each drive shaft (e.g., front and rear) to provide torque to the wheels of the drive shaft. For example, in some cases, only the front drive shaft may be powered (e.g., one or two motors), and the rear drive shaft may be neutralized (e.g., not powered and allowed to rotate freely). In another example, in some cases, both the front drive shaft and the rear drive shaft are power-type (e.g., one or two motors at each shaft). Table 1 provides illustrative examples of configurations that can be implemented by an electric vehicle 100 according to some embodiments of this disclosure, wherein each of the front drive unit 110 and the rear drive unit 120 has the included differential assembly. In some embodiments, only one of the front drive unit 110 and the rear drive unit 120 includes a differential, and only some of the configurations in Table 1 can be implemented or otherwise applied.

[0041] Table 1: Illustrative configurations of vehicles with two drive shafts.

[0042]

[0043] Figure 2 Three exemplary drive unit configurations according to some embodiments of the present disclosure are shown. Configuration 200 includes two separate motor drives 210 and 220, each comprising a motor, a gearbox (e.g., a housing), and an output terminal (e.g., an output key or output half-shaft). A differential assembly 230 is mounted and configured to engage or disengage the output terminals of the motor drives 210 and 220. The housings of the motor drives 210 and 220 are joined together to form a fixed housing.

[0044] Configuration 250 includes motor drives 260 and 270, shown in an exploded view (e.g., unassembled). Motor drives 260 and 270 are configured to be coupled together via an intermediate housing 252. In some embodiments, each of the motor drives 260 and 270, including a motor (e.g., motors 261 and 271), a full gear set (e.g., gear sets 263 and 273), and an output terminal (e.g., half-shafts 264 and 274), need not be configured for independent operation. As shown, motor drives 260 and 270 each include B-shelters 262 and 272, which may be configured to house bearings, manage electrical terminals, provide cooling, provide mounting, any other suitable function, or any suitable combination thereof. In some embodiments, motor drives 260 and 270 do not need to be sealed. For example, the intermediate housing 252 (e.g., an I-shelter) may be configured to seal against both motor drives 260 and 270. The intermediate housing 252 may be configured to seal lubricants (e.g., bearing oil), sealing coolants (e.g., water, mixtures, oils), provide noise reduction (e.g., attenuation of audible noise and vibration caused by gears), align motor drives 260 and 270 with each other, mount motor drives 260 and 270 to a frame or other structural element, house bearings for one or more shafts (e.g., one or more bearings for a motor shaft, intermediate shaft, output shaft, or combinations thereof), and any other suitable functions or any suitable combination thereof. The differential 280 is mounted and configured to engage or disengage the outputs of motor drives 260 and 270.

[0045] Configuration 290 includes motor drives 260 and 270 in an assembled state. For example, motor drives 260 and 270 may be attached to intermediate housing 252 using fasteners (e.g., bolts, threaded studs, and nuts), clamps, locking elements, mechanical interlocks, any other suitable attachments, or any combination thereof. In some embodiments, intermediate housing 252, motor drives 260, motor drives 270, or combinations thereof may include alignment features that spatially align two or more components, constrain relative movement, or both. For example, intermediate housing 252 may allow each of motor drives 260 and 270 to be shorter (e.g., along...). Figure 2 (The left and right axes in the diagram). In another example, configuration 290 may be shorter along the left and right axes than configuration 200, as shown, because motor drives 260 and 270 do not require fully sealed gear sets 263 and 273. Independent motor drives 210 and 220 contain fully sealed housings against lubricant, coolant, or both, and also house all bearings of the respective gear sets.

[0046] Figure 3An exemplary arrangement 300 of gears within a gearbox according to some embodiments of the present disclosure is shown. For clarity, Figure 3 The gearbox housing is not shown. Power system mechanisms (such as gearboxes) can take on various configurations and arrangements based on, for example, design constraints. Figure 3 As shown, for illustrative and clarity purposes, the motor and intermediate gear are offset from each other. Therefore, in some embodiments, the motor and output shaft are aligned on corresponding shafts (e.g., as shown in Figure 1). Figure 8 (As shown). According to this disclosure, the motor, output gear, or both can be aligned on corresponding shafts (e.g., first gears 311 and 321 can be centered about the same axis). For illustration, Figure 3 The offset arrangement allows each power transmission mechanism to be shown (e.g., shown as "V", however the small angle of "V" can be zero degrees to form an arrangement for motor alignment).

[0047] like Figure 3 As shown, each gear set (e.g., gears 311, 315, 316, and 314 form one gear set, and gears 321, 325, 326, and 324 form another gear set) includes double reduction gears. Each motor (e.g., motors 310 and 320) includes a motor shaft with a first gear. For example, first gear 311 is attached to the shaft of motor 310, and first gear 321 is attached to the shaft of motor 320. Each first gear pair has the larger of two intermediate gears that rotate about a central axis. For example, first gear 311 engages with intermediate gear 315 attached to a central shaft. As intermediate gear 315 engages with a corresponding output gear 314 (e.g., connected to a corresponding output shaft 318), intermediate gear 316 is connected to the same central shaft. Furthermore, first gear 321 engages with intermediate gear 325 attached to a central shaft. As an intermediate gear 325 that engages with the corresponding output gear 324 (e.g., connected to a corresponding output shaft 328 aligned with the output shaft 318), intermediate gear 326 is connected to the same intermediate shaft. It should be understood that, as Figure 3As shown, output gears 314 and 324 are aligned, with output gear 324 positioned behind output gear 314, and only output shaft 318 is visible. As described herein, intermediate shafts may be offset from the respective motor shaft and drive shaft (e.g., not aligned along the line). It should be understood that any suitable number of gears can be used with any suitable amount of reduction between the motor and the corresponding output shaft. In some embodiments, the gearbox may include two or more gears in a gear train. The gear train may include a standard gear train or a compound standard gear train. For example, a compound gear train may include two gears configured to rotate about a single axis. Gears may include any suitable gear type, such as, for example, spur gears, parallel helical gears, any other suitable gear type, or any suitable combination thereof. It should be understood that although the exemplary drive unit of this disclosure is shown as including a gearbox and gears, any suitable power transmission mechanism may be used to transmit power from the motor to the output according to this disclosure. For example, chain drive, belt drive may be used. In another example, a belt tensioner, gear teeth, sprockets, any other suitable hardware, or a combination thereof, may be included to transmit power, maintain engagement, or both. In another example, any suitable amount of speed reduction can be included in the power transmission mechanism. As shown, the two included speed reduction stages use a total of three gears; however, the gear set may include, for example, two gears, three gears, or more than three gears. In some embodiments, the power transmission mechanism (e.g., Figure 3 Any one of the gear sets is configured to reduce the rotational speed of the output shaft (e.g., the output shaft) relative to the motor shaft. As used herein, a power transmission mechanism may refer to one or more components between shafts for transmitting power between working shafts. For example, a power transmission mechanism may include gear sets (e.g., multiple gears, each engaging with at least one other gear), single gears (e.g., engaging with other gears, such as input and output gears), bearings, any other suitable components, or any combination thereof. For example, a collection of motor gears, intermediate gears, and output gears may be referred to as a power transmission mechanism, or a single intermediate gear may be referred to as a power transmission mechanism.

[0048] Figure 4 A cross-sectional view of an exemplary arrangement 400 for nested drive gears, clutch assemblies, and differential assemblies according to some embodiments of the present disclosure is shown. For the purpose of illustration, arrangement 600 may, but does not necessarily, resemble [the previous arrangement] when the clutch and differential assemblies are added. Figure 3Arrangement 300. As shown, arrangement 400 represents part of a drive system and includes drive gear 410, drive gear 420, bearings 401 to 404, clutch assemblies 470 and 471, output elements 461 and 462, and differential elements 450 to 452 with actuator 472 (e.g., to lock and unlock drive gear 410 from differential element 451). Drive gear 410 is driven by a first motor (e.g., to a similar manner to...). Figure 2-3 The arrangement shown is such that the drive gear 420 is driven by a second motor (e.g., in a manner similar to...). Figure 2-3 (The arrangement is shown). Bearings 401-404 maintain the alignment of drive gears 410 and 420 along axis 499 during rotation and loading (e.g., axial loading, radial loading, and azimuth loading). As shown, drive gear 420 is radially nested within drive gear 410 along a section, with bearing 401 radially arranged in the middle. As shown, bearings 402 to 404 are arranged in the gearbox housing ( Figure 4 Between a rotating component (not shown) and a stationary element. Clutch assembly 470 is configured to engage and disengage drive gear 410 with output element 461. Similarly, clutch assembly 471 is configured to engage and disengage drive gear 420 with output element 462. Each clutch assembly in clutch assemblies 470 and 471 may include a component mounted to a housing (…). Figure 4 An actuator for a fixed element (not shown). The actuator 470 is configured to engage and disengage the drive gear 410 from the differential elements 450 to 452. In some embodiments, the differential element 450 includes a differential housing that can engage with (e.g., rotate with) the drive gear 410 or disengage from the drive gear 410 (e.g., rotate in a different manner).

[0049] Bearings 401 to 404 may include, for example, roller bearings, needle roller bearings, ball bearings, tapered bearings, thrust bearings, any other suitable type of bearing, or any combination thereof. In some embodiments, bearings 403 and 404 are configured to react against a stationary component (e.g., a housing or other component) to maintain alignment of drive gears 410 and 420 relative to the stationary component. In some embodiments, bearing 402 is configured to react against a stationary component (e.g., a housing or other component) to maintain alignment of drive gear 420 relative to the stationary component. Due to the axial overlap of drive gears 410 and 420, bearing 401 may be configured to transmit forces in the radial direction, axial direction, or both between drive gears 410 and 420.

[0050] Drive gears 410 and 420 (also referred to as “output gears”) are configured to engage with corresponding bearings 403 and 404, which engage with a fixed component (e.g., a housing) to maintain alignment of drive gears 410 and 420. As shown, for “1”, drive gear 410 and output element 461 may be referred to as “left (L)”, while drive gear 420 and output element 462 may be referred to as “right (R)” or “2” herein. In some embodiments, output elements 461 and 462 each include a side gear (e.g., engaging with differential elements 451 and 452), a half-shaft, and a clutch element configured to engage and disengage from the corresponding drive gears 410 and 420 via corresponding clutch assemblies 470 and 471. In some embodiments, output elements 461 and 462 are each configured as output ends and may include output interfaces. For example, output elements 461 and 462 each include a recess configured to receive a half-shaft. In another example, output elements 461 and 462 may include any suitable output interface, such as, for example, a splined interface, a keyed interface, a flanged interface (e.g., with fasteners), a universal joint, a clutch interface, any other suitable interface, or any combination thereof. In an exemplary example, the differential assembly may be referred to as a center-disconnect differential coupled to output elements 461 and 462, and is configured to engage and disengage (e.g., via actuator 472) drive gear 410 and differential element 451 (e.g., including a differential housing).

[0051] Clutch assemblies 470 and 471 of bearing arrangement 400 are configured to mechanically engage drive gears 410 and 420 with corresponding output elements 461 and 462. Clutch assemblies 470 and 471 may include, for example, friction plates, pressure plates, actuators (e.g., hydraulic, electromechanical, or mechanical actuators), centrifugal elements, conical elements, torque limiters, dampers, springs (e.g., to reduce jitter or release engagement), claw clutch elements (e.g., for anti-slip engagement), any other suitable elements, or any combination thereof. Clutch assemblies 470 and 471 may be partially engaged with a fixed component (e.g., a housing or an extension thereof) providing a structure for transmitting forces. For example, a linear actuator may be used to engage the clutch assembly, and the stator of the linear actuator may be attached to the fixed component. In another example, the engagement mechanism of the clutch assembly may be attached to the fixed component to provide a structure against which the reaction force of the engagement mechanism rests.

[0052] In an illustrative example, in torque vectoring mode, when the vehicle is traveling in a straight line on a relatively uniform surface, drive gears 410 and 420 can rotate about axis 499 at substantially the same speed. During steering or in situations where one wheel may experience more traction or more slippage, drive gears 410 and 420 can rotate about axis 499 at different speeds (e.g., drive gears 410 and 420 rotate about axis 499 relative to each other). For example, in some such cases where one wheel experiences slippage, the differential assembly can be engaged to deliver more power to the wheel with greater traction.

[0053] Figures 5 to 7 Some embodiments according to this disclosure are shown. Figure 4 A cross-sectional view of an exemplary arrangement 400 in different driving modes. Figure 5 The torque vectoring distribution mode is shown. Figure 6 The fully locked mode is shown, and Figure 7 The single-motor mode is shown. Additionally, a neutral mode is available, in which the differential assembly and clutch assembly disengage, and therefore the drive shafts are not driven by either motor (e.g., they rotate passively when driving other drive shafts). Figure 4 The axis 499 is included Figures 5 to 7 Each of these can be used for reference.

[0054] refer to Figure 5 This illustrates the torque vectoring distribution mode, with output 510 driven by a first motor and output 520 driven by a second motor. The differential assembly is unlocked (e.g., in...). Figure 5 The figure is shown as a dashed line, where actuator 472 is disengaged, while both clutch assemblies 470 and 471 are locked. For example, in torque vectoring mode, each motor drives its corresponding output (e.g., output elements 461 and 462). In another example, the first motor drives only output 510, and the second motor drives only output 520, and each of outputs 510 and 520 can rotate at different speeds and exhibit different amounts of torque (e.g., outputs 510 and 520 at different speeds). Figure 5 (Hash in different ways).

[0055] refer to Figure 6 This illustrates a fully locked mode, where the differential assembly is disengaged (e.g., via actuator 472), and both clutch assemblies 470 and 471 are engaged, such that output 610 (e.g., including two output shafts to the two wheels) is driven by a first motor, a second motor, or both. Figure 5The torque vectoring distribution mode is different, the output shaft cannot rotate freely independently (e.g., the wheels of the drive shaft rotate at the same speed), and either or both of the motors can be used to drive the output 610. To illustrate, if one wheel slips in the fully locked mode, the torque provided by both the first and second motors can be utilized by the non-slipping wheel in the fully locked mode.

[0056] refer to Figure 7 The diagram illustrates a single-motor mode where clutch assemblies 470 and 471 are both disengaged, and the differential assembly is engaged (e.g., via actuator 472). As shown, only the first motor drives the output terminal 710. The second motor is free to rotate but is not engaged with output terminal 710 and does not provide torque to output terminal 710 (e.g., except for potentially negligible frictional forces from relatively moving surfaces and viscous resistance). For example, in the single-motor mode, a single motor is used to drive the wheel on the drive shaft, thereby reducing the power demand on the drive shaft.

[0057] Figure 8 A cross-sectional view of a drive system 800 with a differential according to some embodiments of the present disclosure is shown. As shown, the drive system 800 includes: a housing 830 including housing elements 831 and 832 and a retaining element 898; output gears 810 and 820; star gears 851 and 852; shafts 850 and a frame 855; side gears 853 and 854; a differential actuator 858; half shafts 861 and 862, which may also be referred to as output shafts 861 and 862 and / or half shafts to constant speed engagement portions 861 and 862; clutch elements 871, 872, 881 and 882; clutch actuators 870 and 880; bearings 801, 802, 803 and 804; and seals 863 and 864.

[0058] The housing 803 is configured to be fixed relative to the output gears 810 and 820, and can be mounted, for example, to the frame of an electric vehicle. The output gears 810 and 820 engage with corresponding gears (not shown), which may be motor gears or intermediate gears that engage with motor gears. Furthermore, although in Figure 8Not shown, but comprising two electric motors coupled directly or via one or more corresponding intermediate gears to housing 830, wherein the respective motor shafts engage drive gears 810 and 820 via corresponding motor gears. Output shafts 861 and 862 (e.g., referred to herein as “half-shafts”) can be coupled to the corresponding wheels of the drive shafts via universal joints, half-shafts, spindles, any other suitable connecting rods, or any combination thereof. Seals 863 and 864 are configured to seal output shafts 861 and 862 to housing 830 to allow azimuth displacement (e.g., rotation about axis 899) while preventing or limiting lubricant leakage from the interior space of housing 830. For illustration, drive system 800 may include an oil lubrication system in which oil is pumped and / or splashed onto components disposed within housing 830, and seals 863 and 864 facilitate containment of lubricant within the interior space of housing 830.

[0059] Output gear 810 interfaces with bearings 801 and 803 to limit displacement deviation of axis 899 (e.g., output gear 810 is restricted to a single degree of freedom of rotation about axis 899). For illustration, output gear 810 may be a single or more rigid assembly. For example, as shown, output gear 810 includes a first part driven and interfaced with clutch element 872 and a second part interfaced with bearing 801. Output gear 820 interfaces with bearings 801, 802, and 804 to limit displacement deviation of axis 899 (e.g., output gear 820 is restricted to a single degree of freedom of rotation about axis 899). Output gears 810 and 820 may rotate relative to each other about axis 899 in some drive modes (e.g., torque vectoring mode, single motor mode, neutral mode) and may be restricted to rotating together (e.g., at the same speed) in some drive modes (fully locked mode).

[0060] Clutch element 871 (e.g., clutch disc) is attached to output shaft 861 (e.g., by key, key, or any other suitable fastener that limits relative azimuth rotation). Clutch element 872 (e.g., clutch disc) is attached to drive gear 810 (e.g., by key, key, or any other suitable fastener that limits relative azimuth rotation). Clutch actuator 870 is configured to engage and disengage clutch elements 871 and 872, thereby engaging or disengaging output gear 810 and output shaft 861. For illustration, when clutch actuator 870 engages clutch elements 871 and 872, output gear 810 and output shaft 861 rotate at the same angular rate, and torque is transmitted between output gear 810 and output shaft 861. In some embodiments, some slippage may occur between clutch elements 871 and 872 when engaged, but in other embodiments, slippage is not required.

[0061] Clutch element 881 (e.g., a clutch disc) is attached to output shaft 862 (e.g., by key, key, or any other suitable fastener that limits relative azimuth rotation). Clutch element 882 (e.g., a clutch disc) is attached to drive gear 820 (e.g., by key, key, or any other suitable fastener that limits relative azimuth rotation). Clutch actuator 880 is configured to engage and disengage clutch elements 881 and 882, thereby engaging or disengaging output gear 820 and output shaft 862. For illustration, when clutch actuator 880 engages clutch elements 881 and 882, output gear 820 and output shaft 862 rotate at the same angular rate, and torque is transmitted between output gear 820 and output shaft 862. In some embodiments, some slippage may occur between clutch elements 881 and 882 when engaged, but in other embodiments, slippage is not required.

[0062] Drive system 800 includes a differential assembly (e.g., a center-disconnect differential) comprising star gears 851 and 852, shaft 850, frame 855, side gears 853 and 854, and differential actuator 858. Frame 855 and shaft 850 may also be referred to as a differential housing, which can be engaged to rotate with or differently from output gear 810. Side gear 853 is attached to output shaft 861 (e.g., via spline connection, keying, or bolting) and configured to rotate with output shaft 861. Side gear 854 is attached to output shaft 862 (e.g., via spline connection, keying, or bolting) and configured to rotate with output shaft 862. Star gears 851 and 852 are configured to rotate about shaft 850. In some embodiments, frame 855 is attached to shaft 850, while in other embodiments, frame 855 and shaft 850 may comprise a single component. Differential actuator 858 is configured to engage and disengage output gear 810 and frame 855. As shown, differential actuator 858 engages, and thus frame 855, shaft 850, and star gears 851 and 852 rotate about axis 899 with output gear 810. Further, as shown, output gear 810 includes key teeth 856 configured to engage with differential actuator 858. Although in Figure 8 It is not visible in the middle, but the frame 855 includes corresponding key teeth, so that in Figure 8In the configuration shown, the differential actuator 858 also engages the key teeth of the frame 855, causing the frame 855 and the output gear 810 to rotate together. The shaft 850, the frame 855, and the assembly including the star gears 853 and 854 are referred herein as a star gear set rotatable about axis 899. In the exemplary example, the differential assembly connects output shafts 861 and 862 together (e.g., and is configured to apply torque separately to output shafts 861 and 862), and the differential actuator 858 is configured to connect and disconnect the output gear 810 from the frame 855 (e.g., the differential housing).

[0063] As shown, bearings 803 and 804 are arranged between housing 830 (e.g., housing elements 831 and 832, respectively) and corresponding output gears 810 and 820 (e.g., their extensions, such as surfaces machined to accommodate bearing journals). Bearings 803 and 804 restrict radial and axial displacement relative to axis 899, while allowing azimuth displacement (i.e., rotation about axis 899). Bearing 801 is arranged between output gears 810 and 820, thereby restricting relative radial displacement while allowing relative azimuth displacement (e.g., relative rotation). Bearing 802 is arranged between output gear 820 and a fixing member 898 of housing 830, thereby restricting at least radial displacement of output gear 820 while allowing azimuth displacement (e.g., rotation about axis 899).

[0064] Figures 9 to 11 Some embodiments according to this disclosure are shown. Figure 8 A cross-sectional view of an exemplary drive system 800 in different drive modes. For clarity, Figure 8 All tags are not included Figures 9 to 11 In the text, and for clarity, bearings, housings, clutch actuators, seals, and other features are omitted. Figures 9 to 11 Shaded lines are used to indicate components constrained to rotate as rigid bodies, as well as components exhibiting potential relative rotation. In the illustrative example, Figures 9 to 11 The driving modes shown correspond to respectively Figures 5 to 7 The driving mode.

[0065] refer to Figure 9This illustrates a torque vectoring distribution mode where output gear 810 is driven by a first motor and output gear 820 is driven by a second motor. The differential assembly is unlocked (e.g., frame 855 disengages from output gear 810), while the two clutch assemblies are locked for at least some time (clutch elements 871 and 872 are engaged with each other, and clutch elements 881 and 882 are engaged with each other). When clutch elements 871 and 872 are engaged, output terminal 861 is driven by output gear 810, and when clutch elements 881 and 882 are engaged, output terminal 862 is driven by output gear 820. For example, in the torque vectoring distribution mode, each motor (e.g., the first and second motors) drives a corresponding output terminal (e.g., output terminals 861 and 862) independently of each other. For illustration, the first motor drives only output gear 810, and the second motor drives only output gear 820, and each of output gears 810 and 820 can rotate at different speeds and exhibit different amounts of torque. The frame 855, shaft 850, and star gears 851 and 852 are rotatable about axis 899 relative to both locking members 910 and 920 (e.g., when the differential is disengaged). Therefore, if the outputs 910 and 920 rotate at different angular rates, star gears 851 and 852 rotate about the axis of shaft 850.

[0066] refer to Figure 10 This illustrates the fully locked mode, where the differential assembly and two clutch assemblies engage, allowing the two output shafts 861 and 862 to be driven as rigid bodies by the first motor, the second motor, or both. Figure 9 The torque vectoring modes differ, and output shafts 861 and 862 cannot rotate freely independently (e.g., the wheels on the drive shafts rotate at the same speed), and either or both of the motors can be used to drive the wheels. To illustrate, if one wheel slips in the fully locked mode, the torque provided by both the first and second motors can be utilized by the non-slipping wheel in the fully locked mode. To further illustrate, star gears 851 and 852 rotate about the axis of shaft 850 because both side gears 853 and 854 are constrained to rotate together (e.g., as part of a rigid body).

[0067] refer to Figure 11The diagram illustrates a single-motor mode where both clutch assemblies are disengaged and the differential assembly is engaged. This single-motor mode (also known as super fuel-saving mode or energy-efficient mode) allows the front drive unit to be reduced from two motors (and gear sets being active) to a single motor (and gear sets used to power the drive shafts, e.g., two front wheels or two rear wheels). In single-motor mode, the first motor, which drives only output gear 810, drives output shafts 861 and 862. In some other drive modes, a second motor driving output gear 820 is freely rotatable but otherwise not engaged with output shafts 861 or 862 and does not provide torque to them. For example, in single-motor mode, a single motor is used to drive the wheels on the drive shaft (e.g., along axis 899), thereby reducing the power requirements of the drive shaft (e.g., involving fewer motors, power electronics, and / or power transmission losses). The differential actuator 858 engages, and thus the frame 855 and shaft 850 rotate about axis 899 with respect to output gear 810. However, clutch actuators 870 and 880 are not engaged (i.e., disengaged), and therefore side gears 853 and 854 are driven by planetary gears 851 and 852. Thus, output shafts 861 and 862 can, but do not necessarily, rotate at the same angular rate. For example, during driving along a straight path, output shafts 861 and 862 rotate at the same speed, and planetary gears 851 and 852 do not rotate relative to the axis of shaft 850. In another example, during driving along an angle or surface with mismatched friction / grip, output shafts 861 and 862 can rotate at different speeds, in which case planetary gears 851 and 852 rotate relative to the axis of shaft 850. Output gear 820 is not engaged with output shaft 862 (or output shaft 861) and is, for example, freely rotatable (e.g., or may rotate relative to viscous resistance as output shaft 862 rotates).

[0068] Figure 12 A perspective partial sectional view of an exemplary drive system 1200 according to some embodiments of the present disclosure is shown. Figure 12 The outer surface of the housing 1230, having housing elements 1231 and 1232 joined together, is shown. Furthermore, Figure 12 A cutaway view is shown, in which some of the housing 1230 is cut open to expose output gears 1210 and 1220. As shown, drive system 1200 includes housing 1230, output gears 1210 and 1220 (e.g., driven by corresponding motors), differential actuator 1272, clutch actuators 1270 and 1271, and output shafts 1261 and 1262. In an exemplary example, drive system 1200 may be coupled with... Figures 8 to 11 The drive system is the same as that of the 800.

[0069] Figure 13A cross-sectional view of a portion of an exemplary drive system 1300 with an integrated differential according to some embodiments of the present disclosure is shown. As shown, the output gear 1310 includes extensions 1311 and 1321; however, it should be understood that the output gear may be a single piece or an assembly configured as a rigid body rotating about axis 1399. For example, extensions 1311 and 1321 rotate as a rigid body having the remainder of the output gear 1310. As shown, the drive system 1300 includes a differential assembly comprising star gears 1351 and 1352, a shaft 1350, a frame 1355, side gears 1353 and 1354, and a differential actuator 1359. Side gear 1353 is configured to be attached to an output shaft (not shown) that engages with interface 1361 (e.g., by spline connection, keying, or bolting) and is configured to rotate with the output shaft. Side gear 1354 is configured to attach to an output shaft (not shown) that engages with interface 1362 (e.g., via a spline connection, key, or bolt) and is configured to rotate with the output shaft. For illustration, side gear 1351 is rotatable relative to output gear 1310 (e.g., its extension 1311) driven by a first motor (not shown), and side gear 1352 is rotatable relative to output gear 1310 (e.g., its extension 1321). Thrust washers 1381 and 1382 are axially arranged between extensions 1311 and 1321, respectively. Thrust washers 1381 and 1382 allow relative angular displacement (e.g., relative rotation) between side gears 1351 and 1352 and their respective extensions 1311 and 1321. Star gears 1351 and 1352 are configured to rotate about the axis of shaft 1350 (e.g., a vertical axis parallel to axis 1301, as shown). In some embodiments, frame 1355 is attached to shaft 1350, while in other embodiments, frame 1355 and shaft 1350 may comprise a single component.

[0070] The differential actuator 1358 is configured to engage and disengage the output gear 1310 and the frame 1355. As shown, the differential actuator 1358 engages, and thus the frame 1355, shaft 1350, and star gears 1351 and 1352 rotate about axis 1399 together with the output gear 1310. Further as shown, the output gear 1310 includes key teeth (in) configured to engage with the plunger 1359 of the differential actuator 1358. Figure 13 (Not visible in the middle). Although in Figure 13 It is not visible in the middle, but frame 1355 includes corresponding key teeth, making it possible to... Figure 13In the configuration shown, the plunger 1359 of the differential actuator 1358 also engages the spline of the frame 1355, causing the frame 1355 and the output gear 1310 to rotate together. The plunger 1359 is configured to translate parallel to the axis 1399 (“axial”) to engage and disengage the output gear 1310 from the differential assembly (e.g., its frame 1355).

[0071] Figure 14 A cross-sectional view of a portion of an exemplary drive system 1400 having a coupling joint according to some embodiments of the present disclosure is shown. The drive system 1400 includes output gears 1410 and 1420 (e.g., by means of...). Figure 14 The corresponding motor drives (not shown) are connected to a coupling 1430 and disconnecting couplings 1412 and 1422. Output gears 1410 and 1420 are configured to be driven independently by their respective electric motors. Disconnecting couplings 1412 and 1422, which may include corresponding clutch assemblies, are configured to engage and disengage output gears 1410 and 1420 with their respective wheels. Coupling 1430, which may include a differential assembly or a clutch assembly, is configured to engage and disengage output gears 1410 and 1420. For example, when engaged, coupling 1430 may allow a fully locked mode and / or a single-motor mode (e.g., driven by either or more of the motors). In another example, when disengaged, coupling 1430 may allow a torque vectoring mode. In some embodiments, each coupling and disconnecting coupling 1412 and 1422 in coupling 1430 may include one or more actuators controlled by a control system to achieve one or more drive modes. In some embodiments, coupling 1430 includes a differential assembly, wherein a star gear set is coupled to one of the output gears 1410 and 1420, and wherein the output shaft is coupled to a corresponding side gear that engages with the star gear set.

[0072] Figure 15 A cross-sectional view of a portion of a drive system 1500 having an intermediate differential assembly 1550 according to some embodiments of the present disclosure is shown. As shown, the differential assembly 1550 includes a housing 1530, rather than being integrated within a drive system housing (e.g., as shown in the figure). Figure 8 (As shown). The drive system 1500 includes output gears 1510 and 1520, bearings 1501 to 1504, and a differential assembly 1550. The differential assembly 1550 may be bolted or otherwise mounted to the housing surrounding the output gears 1510 and 1520. For illustration, in some embodiments, as an add-on rather than an integrated component, the differential assembly 1550 may be mounted between existing housings corresponding to each of the output gears 1510 and 1520.

[0073] Bearings 1501 and 1502 are configured to limit the radial and axial displacement of the output gear 1510 relative to axis 1599, while allowing the output gear 1510 to undergo azimuth displacement (e.g., rotation) about axis 1599. Bearings 1503 and 1504 are configured to limit the radial and axial displacement of the output gear 1520 relative to axis 1599, while allowing the output gear 1520 to undergo azimuth displacement (e.g., rotation) about axis 1599. The differential assembly 1550 includes a housing 1530 configured to be fixed and a set of planetary gears configured to engage. Figure 15 Side gears 1551 and 1552 (not shown in the figure). As shown, each of the side gears 1551 and 1552 includes a side gear for coupling to the corresponding output shaft (similar to...). Figure 8 The drive shaft (800) has keyed teeth. The differential assembly 1550 may also include actuators for locking and unlocking the differential. For example, when locked, the drive shaft is fully locked (e.g., output gears 1510 and 1520 rotate at the same rate), and when unlocked, the drive shaft can be in neutral or torque vectoring mode.

[0074] Figure 16 A cross-sectional view of a portion of an exemplary drive system 1600 having an intermediate differential and an intermediate clutch according to some embodiments of the present disclosure is shown. As shown, the drive system 1600 includes output gears 1610 and 1620, a planetary gear differential 1650, output shafts 1661 and 1662, and bearings 1601 to 1604. Although in Figure 16 Not shown, but the drive system 1600 also includes a housing with fixed components. The differential assembly 1650 may be bolted or otherwise mounted to the housing surrounding the output gears 1610 and 1620. For illustration, in some embodiments, as an addition rather than an integrated component, the differential assembly 1650 may be mounted in an existing housing corresponding to each of the output gears 1610 and 1620. Output gear 1620 drives output shaft 1662, which rotates with gear 1652; all these components rotate with housing 1630. Output gear 1610 drives output shaft 1661, which rotates with gear 1651.

[0075] Bearings 1601 and 1602 are configured to limit the radial and axial displacement of output gear 1610 relative to axis 1699, while allowing the output gear 1610 to undergo azimuth displacement (e.g., rotation) about axis 1699. Bearings 1603 and 1604 are configured to limit the radial and axial displacement of output gear 1620 relative to axis 1699, while allowing the output gear 1620 to undergo azimuth displacement (e.g., rotation) about axis 1699. Differential assembly 1650 includes a rotatable housing 1630, planetary gear 1653, and gears 1651 and 1652 configured to engage planetary gear 1653. Each of gears 1651 and 1652 may include key teeth or keys for coupling to corresponding output shafts 1661 and 1662. Differential assembly 1650 may also include actuators for locking and unlocking the differential. For example, when locked, the drive shaft is fully locked (e.g., output gears 1610 and 1620 rotate at the same rate), and when unlocked, the drive shaft can be in neutral or torque vectoring mode. To illustrate, when unlocked, planetary gear 1653 can rotate about axis 1699, and gears 1651 and 1652 can rotate about axis 1699 at different rates.

[0076] Figure 17 A cross-sectional view of an exemplary drive system 1700 according to some embodiments of the present disclosure is shown. As shown, the drive system 1700 includes a housing 1730, motors 1701 and 1702, intermediate gear sets 1711 and 1721, output gears 1710 and 1720, output terminals 1761 and 1762, and mounting members 1705 and 1706. As shown, the drive system 1700 does not include a differential assembly, although a suitable differential assembly may be an integrated gear or output gears 1710 and 1720, and output terminals 1761 and 1762 may be replaced by output gears having an integrated differential assembly. Motors 1701 and 1702 include corresponding motor gears that engage with the corresponding intermediate gear sets 1711 and 1721, which in turn engage with the corresponding output gears 1710 and 1720. Output terminals 1761 and 1762 include disconnecting connectors and are splined to engage with corresponding drive shafts. Mounting elements 1705 and 1706 attach housing 1730 to the electric vehicle and may include fasteners, bushings, any other suitable components, or any combination thereof. Clutch assemblies 1770 and 1780 respectively allow engagement of output gear 1710 and output terminal 1761 and engagement of output gear 1720 and output terminal 1762. In an exemplary example, Figures 2 to 16The exemplary arrangement and any of the drive systems can be converted into drive system 1700, or combined with drive system 1700 to provide differential functionality. For illustration purposes, output gears 1710 and 1720, as well as any other suitable components, can be redesigned, replaced, or otherwise modified to accommodate differential components.

[0077] Figure 18 A block diagram of an exemplary electric vehicle 1800 with a control system for controlling one or more drive units, according to some embodiments of the present disclosure, is shown. The electric vehicle 1800 includes a battery pack 1830, an electric vehicle subsystem 1810, suspension, and wheels. The electric vehicle subsystem 1810 includes, for example, a rear drive unit 1812, a front drive unit 1814, control circuitry 1816, auxiliary systems 1818, an input interface 1820, and any other suitable corresponding devices. The electric vehicle 1800 includes a power transmission mechanism 1850 (e.g., a gearbox, pulley system, or other mechanism for transferring the operation of the drive shaft) corresponding to one drive shaft (e.g., a rear drive shaft) and a power transmission mechanism 1860 corresponding to another drive shaft (e.g., a front drive shaft). For example, the electric vehicle 1800 may be coupled with… Figure 1 The electric vehicle 100 is identical, wherein the front drive unit 110 and the rear drive unit 120 correspond to the power transmission mechanisms 1860 and 1850, respectively. In another example, vehicle 1800 may include... Figures 2 to 17 The exemplary arrangement and any of the drive systems that are part of either or both of the power transmission mechanisms 1850 and 1860. Vehicle subsystem 1810 can be used, for example, to monitor... Figures 2 to 17 The exemplary arrangement and operation of any of the drive systems (e.g., sensor signals). Figures 2 to 17 The exemplary arrangement and control actuators (e.g., clutch actuators and / or differential actuators) of any of the drive systems, or otherwise managed. Figures 2 to 17 Any exemplary arrangement and operation of the drive system. For illustration, each of the power transmission mechanisms 1850 and 1860 may include a left-side gear train corresponding to the left half-shaft and a right-side gear train corresponding to the right half-shaft.

[0078] In some embodiments, control circuitry 1816 may include processing devices, memory, power management components, and any other suitable components for controlling one or more drive units (e.g., front drive unit 1814 and rear drive unit 1812) or any combination thereof. For example, control circuitry 1816 may control the phase current (e.g., the amount and direction of the current) flowing to the electric motors of one or more drive units (e.g., using power stored in battery pack 1830). In another example, for one or more clutch assemblies, control circuitry 1816 may control clutch operation (e.g., using an electromagnetically actuated clutch). In another example, control circuitry 1816 may control differential operation in a dual drive unit (e.g., using an electromagnetically actuated differential). In some embodiments, control circuitry 1816 is configured to actuate and deactivate one or more clutch actuators (e.g., first and second clutch actuators), differential actuators, or combinations thereof. For example, the control circuitry may provide control signals (e.g., communication, electricity, or both) to (i) one or more clutch actuators of the power transmission mechanisms 1850, 1860, or both, (ii) one or more differential actuators of the power transmission mechanisms 1850, 1860, or both, or (iii) combinations thereof. In another example, the control signals may be binary (e.g., an on / off application of DC voltage), analog (e.g., control signals may be proportional based on voltage range, pulse width modulation, or pulse density modulation), oscillatory (e.g., and AC signals or other oscillating signals), any other suitable waveform or shape (e.g., square wave, sawtooth wave, triangular wave, rectified sine wave), or any combination thereof. In some embodiments, the actuators are spring-loaded or otherwise biased to an engaged or disengaged state, and the application of electrical, hydraulic, or pneumatic power from the vehicle subsystem 1810 causes a change in state (e.g., engaged to disengaged, or disengaged to engaged).

[0079] In some embodiments, control circuitry 1816 may include one or more sensors, one or more sensor interfaces (e.g., for sensors included as part of a drive unit), corresponding wiring, corresponding signal conditioning components, any other suitable components for sensing the state of the drive unit, or any combination thereof. For example, control circuitry 1816 may include a speed sensor (e.g., a rotary encoder), a current sensor, a voltage sensor, a temperature sensor, any other suitable sensor, or any combination thereof. In some embodiments, control circuitry 1816 may be implemented by a central controller, multiple distributed control systems, an embedded system, or any combination thereof. For example, control circuitry 1816 may be implemented at least partially by an electronic control unit (ECU). In another example, the electric vehicle may include a power electronics system controlled by an ECU and configured to manage current flowing to one or more electric motors of one or more drive units. Rear drive unit 1812 may be coupled to the wheels of the electric vehicle via half-shafts, constant speed engagements, one or more suspension / steering components, any other suitable couplings, or any suitable combination thereof. Front drive unit 1814 may be coupled to the wheels of the electric vehicle via half-shafts, constant speed engagements, one or more suspension / steering components, any other suitable couplings, or any suitable combination thereof. For example, a wheel can be mounted to a hub containing bearings for half-shafts, wherein the hub is connected to a suspension / steering component (e.g., where the drive unit is also mounted to the vehicle frame) that is mounted to the vehicle frame.

[0080] In some embodiments, the drive system may include a first drive unit and optionally a second drive unit, each comprising one or more clutch assemblies and a differential assembly. In some embodiments, in addition to including drive units (e.g., a single drive unit or dual drive units), the system may also include processing equipment configured to enable and de-enable clutch assemblies to transmit torque, manage motor operation, manage regeneration (e.g., using the motor as a generator), perform any other control functions, or any combination thereof. Enabling and de-enabling clutch assemblies may refer to fully or partially increasing or decreasing the engagement of elements of the clutch assembly (e.g., using control circuitry). For example, enabling clutch assemblies may include fully locking the clutch, allowing some slippage of the clutch, or otherwise transferring the amount of torque between the output shafts. In some embodiments, the drive unit may include at least one sensor configured to sense wheel slip (e.g., a sensor interface coupled to control circuitry), and the control circuitry may be further configured to receive signals from at least one sensor, detect occurring wheel slippage, and enable the clutch assembly, differential assembly, or combination thereof in response to detecting occurring wheel slippage. For example, sensors can detect shaft speed (e.g., output shaft speed measured by an encoder) or output torque (e.g., output shaft torque or motor torque). In some embodiments, the drive system may include an accelerator pedal configured to indicate a desired speed (e.g., by user pressing it), and if the speed parameter exceeds a threshold, processing equipment can receive a signal from the accelerator pedal, determine the speed parameter based on the signal, and enable one or more clutch assemblies, one or more differential assemblies, one or more motors, or combinations thereof. For example, if the user “presses” the accelerator pedal (e.g., more than 50% of the required pressure), control circuitry can enable the clutch and differential assemblies to lock the output shafts of the drive shaft together. In some embodiments, control circuitry can enable and de-enable the clutch or differential assemblies based on road conditions (e.g., icy roads, puddles, strong winds), drive mode (e.g., off-road mode, sport mode, or traction mode), any other suitable criteria, or any combination thereof.

[0081] In some embodiments, one or more brackets attached to one or more locations may be used to rigidly connect the two motors of the dual drive unit, the two power transmission mechanism housings of the dual drive unit, or both, to ensure that all components of the dual drive unit act as a single rigid body under normal operating conditions. In some embodiments, protrusions, tabs, or other suitable features may be included on the housing to facilitate mounting.

[0082] In some implementations, one or more drive units may be included in the vehicle. For example, Tables 2a and 2b include some exemplary drive modes according to this disclosure. The four exemplary drive modes included in Table 2 correspond to a single drive shaft and can be applied to each drive shaft (e.g., independently of each other or dependent on each other). For illustration, the torque vectoring mode allows for completely independent wheel mechanisms, the super fuel-saving mode allows a single motor to drive the drive shaft (e.g., single motor propulsion distributed to two wheels), and the locking mode allows for two peak torques from either motor.

[0083] Table 2a: Illustrative drive mode with differential lock on the left (L) gear set.

[0084]

[0085] Table 2b: Illustrative drive mode with differential lock on the left (L) gear set.

[0086]

[0087]

[0088] It is supplied to a single wheel (e.g., a wheel with traction), and the neutral mode allows for horizontal traction (e.g., the motor does not provide active torque to the output shaft). In some implementations, the center disconnect differential engages with motor one (e.g., as...). Figures 4 to 11 and Figures 13 to 17 The left motor (as shown) and motor two (e.g., another motor) quickly engage to provide left-to-right differential torque. For example, this can be used to quickly provide a transition from super fuel-saving mode to torque vectoring (e.g., from single-motor mode to dual-motor mode). As shown in Tables 2a and 2b, the output gear (e.g., and corresponding half-shaft) that engages with the housing of the center disconnect differential may be referred to herein as "left (L)" relative to "1", while the other output gear (e.g., and corresponding half-shaft) may be referred to herein as "right (R)" or "2".

[0089] Figure 19 A flowchart of an exemplary process 1900 for managing an electric vehicle drive system according to some embodiments of this disclosure is shown. Process 1900 may be performed by... Figure 18 This can include any suitable drive system, such as Figures 1 to 17The electric vehicle 1800 is implemented with those drive systems shown. For example, control circuitry 1816 can execute computer instructions to control one or more clutch actuators (e.g., for one or more drive shafts), one or more differential actuators (e.g., for one or more drive shafts), receive sensor signals from one or more sensors, retrieve reference information, any other suitable function, or any combination thereof, to implement process 1900. In some embodiments, for example, the system implementation includes the application of computer-executable instructions stored on a non-transitory computer-readable medium.

[0090] At step 1902, the system determines the drive mode for each of the one or more drive shafts. In some embodiments, the system selects one drive mode from a variety of drive modes (e.g., drive modes as shown in Tables 2a and 2b). The system may determine the drive mode based on: torque command, current command, speed (e.g., wheel speed, shaft speed, gear speed, or their relative speed), energy consumption metric, energy storage metric (e.g., ... Figure 18 The system may receive the state of charge of the battery system 1830, user input received at the input interface 1820, reference information (e.g., stored in a database or otherwise stored in memory), any other suitable information, or any combination thereof. The system may implement or take inputs, sensor inputs, user inputs, reference information, executable instructions, logical commands, any other suitable information or instructions, or any combination thereof.

[0091] In some embodiments, at step 1902, the system takes input signals from one or more sensors, such as current signals (e.g., current in a DC bus, current in one or more motor phases), voltage signals (e.g., voltage across a DC bus, voltage across one or more motor phases), rotational position information (e.g., angular position of charge, velocity or acceleration, shaft or gear), battery pack information (e.g., state of charge, estimated remaining battery life, fault information, usage information, energy consumption rate), pedal position information (e.g., from a drive control pedal for acceleration or braking), reference settings stored in memory, any other suitable information, or any combination thereof. In some embodiments, the system receives from input interface 1820 an input selection indicating that the user has selected a specific drive mode (e.g., using a rotatable knob, touchscreen, button, voice command, or any other suitable input type). In some embodiments, at step 1902, the system may identify the drive mode. For example, the system may recognize the full lock mode (e.g., and proceed to step 1904) in the following situations: when selected by the user; when the vehicle is traveling along a straight path; when the vehicle has consistent traction at both wheels of the drive axle; when maximum acceleration or very high acceleration is required; or based on any other suitable criterion; or a combination thereof. In another example, the system may recognize the single-motor mode (e.g., and proceed to step 1906) in the following situations: when selected by the user; when the vehicle is traveling a long distance; when the vehicle has consistent traction at both wheels of the drive axle; when maximum acceleration or very high acceleration is not required; or based on any other suitable criterion; or a combination thereof. In another example, the system may recognize the torque vectoring distribution mode (e.g., and proceed to step 1908) in the following situations: when selected by the user; when the vehicle is traveling off-road; when the vehicle has inconsistent traction at both wheels of the drive axle; when the road conditions are dynamic or slippery; when maximum acceleration or very high acceleration is intermittently required; when tank turns are required; or based on any other suitable criterion; or a combination thereof. In another example, the system may recognize the neutral mode (e.g., and proceed to step 1910) in the following situations: when selected by the user; when the vehicle is traveling a long distance; when the road conditions are consistent and not slippery; when maximum road conditions or large acceleration are not required; or based on any other suitable criteria; or a combination thereof.

[0092] At step 1904, the system achieves a fully locked mode. For example, in the fully locked mode, the drive shaft is driven by two motors (e.g., the vehicle may be front-wheel drive, rear-wheel drive, or both). In some embodiments, at step 1906, the system engages or causes the first clutch to engage, engages or causes the second clutch to engage, engages or causes the differential to engage, and controls the rotation of the first motor, the second motor, or both. For example, the system may apply current to the phase of either or both of the first and second motors to generate torque at the fully locked output, which drives two wheels rotating at the same angle (e.g., although not necessarily the same torque). For illustration, any of the first clutch, the second clutch, and the differential may be configured to engage without input (e.g., normally engaged), disengage without input (e.g., normally disengaged), or require input to definitively engage or disengage. In some embodiments, step 1904 includes an actuator that generates a signal and transmits the signal to the first clutch assembly, the second clutch assembly, the differential assembly, or a combination thereof. In an illustrative example, in Figure 6 and Figure 10 The fully locked mode is shown in the image.

[0093] At step 1906, the system implements a single-motor mode. For example, in single-motor mode, the drive shaft is driven by a single motor (e.g., the vehicle may be front-wheel drive, rear-wheel drive, or both). In some embodiments, at step 1906, the system disengages or disengages the first clutch, disengages or disengages the second clutch, engages or engages the differential, and controls the rotation of the first motor. For example, the system may allow the second motor to rotate freely without electrical input, mechanically lock the motor in place, or otherwise not provide phase current to the second motor. For illustration, any of the first clutch, second clutch, and differential may be configured to engage without input (e.g., normally engaged), disengage without input (e.g., normally disengaged), or require input to definitively engage or disengage. In some embodiments, step 1906 includes an actuator that generates a signal and transmits the signal to the first clutch assembly, second clutch assembly, differential assembly, or a combination thereof. In an illustrative example, in Figure 7 and Figure 11 The single-motor mode is shown in the diagram.

[0094] At step 1908, the system implements a torque vectoring distribution mode. For example, the drive shaft in torque vectoring distribution mode allows independent control of two wheels (e.g., the vehicle may be front-wheel drive, rear-wheel drive, or both). In some embodiments, at step 1908, the system engages or causes the first clutch to engage, engages or causes the second clutch to engage, disengages or disengages the differential, and controls the rotation of both the first motor and the second motor. For example, by providing current to the phases of the first and second motors, the system can provide the same or different torques to each wheel of the drive shaft. For illustration, any of the first clutch, second clutch, and differential may be configured to engage without input (e.g., normally engaged), disengage without input (e.g., normally disengaged), or require input to definitively engage or disengage. In some embodiments, step 1908 includes an actuator that generates a signal and transmits the signal to the first clutch assembly, second clutch assembly, differential assembly, or a combination thereof. In an illustrative example, in Figure 5 and Figure 9 The torque vectoring distribution mode is shown in the figure.

[0095] At step 1910, the system achieves a neutral mode. For example, in neutral mode, the drive shaft is towed by another drive shaft (e.g., the vehicle is front-wheel drive or rear-wheel drive, but not both simultaneously). In some embodiments, at step 1910, the system disengages or disengages the first clutch, disengages or disengages the second clutch, disengages or disengages the differential. In some embodiments, at step 1910, the system allows both the first and second motors to rotate freely (e.g., in the absence of electrical input). For example, by supplying current to the phases of the first and second motors, the system can supply the same or different torques to each wheel of the drive shaft. For illustration, any of the first clutch, second clutch, and differential can be configured to engage without input (e.g., normally engaged), disengage without input (e.g., normally disengaged), or require input to definitively engage or disengage. In some embodiments, step 1910 includes an actuator that generates a signal and transmits the signal to the first clutch assembly, second clutch assembly, differential assembly, or a combination thereof.

[0096] At step 1912, the system updates the drive mode for one or more drive shafts. For example, in some embodiments, the system updates the drive mode for each drive shaft. In another example, in some embodiments, the system updates the drive mode for each drive shaft having a differential assembly. In yet another example, in some embodiments, the system updates the drive mode for a specific drive shaft. The system can update the drive mode at a predetermined frequency, i.e., a frequency dependent on operating parameters (e.g., vehicle speed, axle speed, gear speed), and respond to events (e.g., changes in operating parameters, input received at the input interface).

[0097] In illustrative examples, referring to a vehicle with two drive shafts (e.g., a front drive unit and a rear drive unit), several vehicle modes can be achieved. For example, Table 3 shows several configurations that can be generated by combining Tables 1 and 2. Some of the configurations in Table 3 may be inaccessible to the drive shafts without requiring a dual clutch to disengage the output shaft from the output gear. For example, the drive unit of this disclosure may be contained at the front drive shaft, the rear drive shaft, or both, with a specific arrangement controlling the accessible configuration.

[0098] Table 3: Illustrative configurations of vehicles with two drive shafts.

[0099]

[0100] By implementing a differential between the output gears of the front or rear drive unit and having a selective clutch to change the torque path, the system is capable of powering two wheels of the drive shaft with a single motor and / or gear set. For example, the system can achieve a 5% or more improvement in total vehicle travel in single-motor mode. In another example, a locking mode can allow for an additional 5% travel improvement by reducing the torque output of the motor and gearbox, while maintaining peak torque on each wheel by locking the differential. In yet another example, neutral is achieved by disconnecting the two wheels, which can be advantageous for maintenance or leveling towing vehicles (e.g., behind a truck or recreational vehicle). The configurations disclosed herein allow for flexibility in drive modes and significant travel improvements relative to other two- or three-wheeled vehicle architectures.

[0101] The foregoing description is merely illustrative of the principles of this disclosure, and various modifications can be made by those skilled in the art without departing from the scope of this disclosure. The above embodiments are presented for illustrative purposes and not for limitation. This disclosure may also take many forms other than those expressly described herein. Therefore, it should be emphasized that this disclosure is not limited to the methods, systems, and instruments expressly disclosed, but is intended to include variations and modifications thereof, which are within the spirit of the following claims.

Claims

1. A drive system for a vehicle, the drive system comprising: a first output gear driven by a first electric machine; a first clutch assembly configured to couple and decouple the first output gear to a first half shaft couplable to a first wheel; a second output gear driven by a second electric machine; a second clutch assembly configured to couple and decouple the second output gear to a second half shaft couplable to a second wheel; and a center split differential configured to couple the first output gear to the first half shaft and to the second half shaft; wherein the drive system further comprises a control circuit; the first clutch assembly comprises a first actuator coupled to the control circuit; the second clutch assembly comprises a second actuator coupled to the control circuit; the drive system comprises a third actuator coupled to the control circuit and configured to engage and disengage the first output gear to a differential housing; the control circuit is configured to actuate and de-actuate each of the first actuator, the second actuator, and the third actuator; wherein the control circuit is configured to: implement a first drive mode in which the first clutch assembly is engaged, the second clutch assembly is engaged, and the center split differential is disengaged; implement a second drive mode in which the first clutch assembly is engaged, the second clutch assembly is engaged, and the center split differential is engaged and configured such that the first and second half shafts are not independently free to rotate; and implement a third drive mode in which the first clutch assembly is disengaged, the second clutch assembly is disengaged, and the center split differential is engaged.

2. The drive system of claim 1, wherein the first and second electric machines are configured to be independently controlled.

3. The drive system of claim 1 or 2, wherein the center split differential comprises: a spider gear set coupled to a differential housing; a first side gear coupled to the first half shaft and engaged with the spider gear set; a second side gear coupled to the second half shaft and engaged with the spider gear set; a first thrust washer disposed between the first side gear and the first output gear; and a second thrust washer disposed between the second side gear and a fixed portion of the housing.

4. A method for managing drive modes of a drive axle, the method comprising: controlling a first clutch coupling a first output gear and a first half shaft of the drive axle; controlling a second clutch coupling a second output gear and a second half shaft of the drive axle; controlling a differential configured to couple the first output gear to the first half shaft and to the second half shaft; and ​ ​ ​ controlling at least one of a first electric machine coupled to the first output gear or a second electric machine coupled to the second output gear; determining to implement a full-lock drive mode at the drive axle; and implementing the full-lock drive mode by: causing the first clutch to be engaged; causing the second clutch to be engaged; and causing the differential to be engaged such that the first and second half axles cannot freely rotate independently.

5. The method of claim 4, further comprising: determining to implement a torque vectoring mode at the drive axle; and implementing the torque vectoring mode by: causing a first clutch coupling a first output gear and a first half axle of the drive axle to be engaged; causing a second clutch coupling a second output gear and a second half axle of the drive axle to be engaged; causing a differential configured to couple and decouple the first and second half axles to be decoupled, and controlling rotation of the first electric machine and rotation of the second electric machine independently.

6. The method of claim 4, further comprising: determining to implement a single electric machine drive mode; and implementing the single electric machine drive mode by: causing the first clutch to be decoupled; causing the second clutch to be decoupled; causing the differential to be engaged; and controlling rotation of the first electric machine.

7. The method of claim 6, further comprising allowing the second electric machine to freely rotate without power input.

8. The method of any one of claims 4-7, further comprising: determining to implement a neutral drive mode at the drive axle; and implementing the neutral drive mode by: causing the first clutch to be decoupled; causing the second clutch to be decoupled; causing the differential to be decoupled; and allowing both the first electric machine and the second electric machine to freely rotate without power input.

9. The method of any one of claims 4-7, further comprising determining a drive mode based on at least one of: a signal from a speed sensor, an energy consumption metric, an input to a user interface, a torque value of the first electric machine, or a torque value of the second electric machine.

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