Electric drive module and method for operating an electric drive module

Abstract

Method for controlling the power transmission in a vehicle (12) to a set of vehicle wheels (20, 22), the method comprising: Providing a drive module (10) for supplying the set of vehicle wheels (20, 22), wherein the drive module (10) is operable in a torque-vectoring mode and in at least one propulsion mode; Switching the drive module (10) to the torque vectoring mode when a first set of conditions is met; Switching the drive module (10) to one of the propulsion modes when a second set of conditions is met; Switching the drive module (10) to one of the propulsion modes when a third set of conditions is met; where the first sentence has conditions: a torque requested by an operator of the vehicle (12) is less than or equal to a first predetermined request threshold; and a speed of the vehicle (12) is greater than or equal to a first predetermined speed threshold; the second sentence contains conditions: the speed of the vehicle (12) is less than a second predetermined speed threshold; and a lateral instability of the vehicle (12) is less than or equal to a first predetermined instability threshold; and the third set of conditions includes: The torque requested by the operator of the vehicle (12) is greater than a second predetermined request threshold.

Description

AREA

[0001] The present disclosure relates to an electric drive module and a method for operating an electric drive module. BACKGROUND OF THE REVELATION

[0002] One means of correcting or reducing understeer or oversteer in a vehicle is a torque-vectoring differential (TVD). TVDs are typically electronically controlled differentials capable of generating a torque across the vehicle's center of gravity, independent of the speed of the vehicle's wheels, which would be used to correct or reduce understeer or oversteer.

[0003] US Patent 7,491,147 B2 discloses an internal combustion engine-driven TVD that employs a pair of speed control mechanisms arranged on opposite sides of a differential mechanism. Each speed control mechanism comprises a (front) reduction gear and a friction clutch. The reduction gear transmits torque from a differential housing of the differential mechanism to the friction clutch and from the friction clutch to an associated (axle) output shaft.

[0004] DE 10 2006 031 089 A1 relates to a drive device for motor vehicles for driving at least one axle with two wheels of the motor vehicle connected via a differential and drive shafts.

[0005] DE 10 2007 055 881 A1 describes a transmission device, in particular for motor vehicles, with at least two output shafts and two interconnected, multi-shaft planetary gear sets.

[0006] DE 600 05 427 T2 relates to a power transmission system for controlling the distribution of drive torque between the front and rear drive train of a motor vehicle with all-wheel drive.

[0007] DE 600 05 573 T2 describes two-speed transfer cases for use in four-wheel drive vehicles.

[0008] DE 698 21 879 T2 discloses a transfer case for use in vehicles with all-wheel drive.

[0009] Similarly, US Patent US 7,238,140 B2 discloses an internal combustion engine-driven torque diverter (TVD) that employs a pair of torque diverters arranged on opposite sides of a differential mechanism. Each torque diverter includes a reduction gear and a magnetic powder brake. The reduction gear transfers torque from a differential housing of the differential mechanism to an output element coupled to an associated axle output shaft for common rotation. The magnetic powder brake is configured to selectively brake the output element of the reduction gear.

[0010] US patent application publication US 2010 / 0323837A1 discloses an electrically driven TVD comprising a pair of planetary gears, an electric motor, and a sleeve that controls the operation of the planetary gears. The TVD can operate in a first mode, in which the TVD is configured as an open differential driven by the electric motor, and in a second mode, in which the TVD produces a torque-vectoring output.

[0011] Other TVDs utilize two electric motors, one dedicated to driving an open differential and the other providing torque vectoring to an output element of the open differential. Such a setup can be complex and expensive.

[0012] While such setups can be effective for implementing a torque vectoring function, in which torque can be reallocated from one axle shaft to another via the differential mechanism, TVDs are still capable of improvement. SUMMARY OF THE REVELATION

[0013] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its scope of protection or all of its features.

[0014] In one embodiment, the present teaching provides a method for controlling the transmission of force to a set of vehicle wheels. The method may include providing a drive module for driving the set of vehicle wheels. The drive module may be operable in a torque-vectoring mode and at least one propulsion mode. The method may include switching the drive module to the torque-vectoring mode when a first set of conditions is met. The method may include switching the drive module to one of the propulsion modes when a second set of conditions is met. The method may include switching the drive module to one of the propulsion modes when a third set of conditions is met.The first set of conditions may include: a torque requested by the operator of the vehicle that is less than or equal to a first predetermined request threshold; and a vehicle speed that is greater than or equal to a first predetermined speed threshold. The second set of conditions may include: the vehicle speed is less than a second predetermined speed threshold; and the vehicle's lateral instability is less than or equal to a predetermined instability threshold. The third set of conditions may include: the torque requested by the operator of the vehicle is greater than a second predetermined request threshold.

[0015] In a further embodiment, the present teaching provides a control unit for a drive module that can be operated in a variety of modes to drive a pair of vehicle wheels. The control unit can be configured to determine a torque requested by a vehicle operator, a vehicle speed, and a level of vehicle instability. The control unit can be configured to switch the drive module to a torque-vectoring mode when a first set of conditions is met. The control unit can be configured to switch the drive module to a propulsion mode when either a second set of conditions is met or a third set of conditions is met.The first set of conditions may include: a torque requested by the operator of the vehicle that is less than or equal to a first predetermined request threshold; and a vehicle speed that is greater than or equal to a first predetermined speed threshold. The second set of conditions may include: the vehicle speed is less than a second predetermined speed threshold; and the vehicle's lateral instability is less than or equal to a predetermined instability threshold. The third set of conditions may include: the torque requested by the operator of the vehicle is greater than a second predetermined request threshold.

[0016] The present teaching further provides a drive module, including a motor, an input element, a differential assembly, a transmission, a switchable element, an actuator, and a control module. The input element can be driven by the motor. The differential assembly can have a differential carrier and first and second differential outputs, which can be accommodated in the differential carrier. The transmission can receive torque from the input element. The switchable element can be axially movable between a first position and a second position. Positioning the switchable element in the first position can couple the transmission to the differential assembly to establish a torque-vectoring mode in which the transmission applies an equal but oppositely directed torque to the first and second differential outputs.Positioning the switchable element in the second position can couple the transmission to the differential assembly and directly drive the differential carrier. The actuator can be coupled to the switchable element and configured to move it axially between the first and second positions. The control module can be configured to control the actuator to move the switchable element to the first position when a first set of conditions is met. The control module can be configured to control the actuator to move the switchable element to the second position when a condition of a second set of conditions is met, or when a third set of conditions is met.The first set of conditions may include: a torque requested by the operator of the vehicle that is less than or equal to a first predetermined request threshold; and a vehicle speed that is greater than or equal to a first predetermined speed threshold. The second set of conditions may include: the vehicle speed is less than a second predetermined speed threshold; and the vehicle's lateral instability is less than or equal to a predetermined instability threshold. The third set of conditions may include: the torque requested by the operator of the vehicle is greater than a second predetermined request threshold.

[0017] Further areas of application will become apparent from the descriptions provided herein. The description and specific examples in this summary are intended for illustrative purposes only and are not meant to limit the scope of protection of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein serve only to illustrate selected embodiments and not all possible implementations, and are not intended to limit the scope of protection of the present disclosure. Fig. Figure 1 illustrates a sectional view of a drive module, including a drive mechanism for torque distribution, which according to a first embodiment can be operated in several modes; Fig. Figure 2 illustrates a sectional view of a drive module, including a drive mechanism for torque distribution, which, according to a second embodiment, can be operated in several modes; Fig. Figure 3 is a longitudinal sectional view of a part of a drive module, including a drive mechanism for torque distribution, which according to a third embodiment is operable in several modes; Fig. 4 is an enlarged part of Fig. 3; Fig. 5 is a diagram of a first logic routine for switching between modes of a drive mechanism for torque distribution, such as in the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 shown; and Fig. Figure 6 is a diagram of a second logic routine for switching between modes of a drive mechanism for torque distribution, such as in Fig. 2 shown.

[0019] The corresponding reference numbers denote the corresponding parts in all views of the drawings. DETAILED DESCRIPTION

[0020] With reference to Fig. 1. An axle assembly (e.g., a drive module) constructed according to the teachings of the present disclosure is generally designated by reference numeral 10. For example, the axle assembly 10 may be constructed in accordance with US patent US 8,663,051 B2 or in accordance with US patent application publication 2014 / 0364264 A1, the disclosures of which are hereby incorporated by reference. The axle assembly 10 could, for example, be a front axle assembly or a rear axle assembly of a vehicle 12. The axle assembly 10 may comprise a drive mechanism for a torque distribution 14a, a first output element 16, a second output element 18, a left wheel 20, and a right wheel 22. The drive mechanism 14a can be used to transmit torque to the first output element 16 and the second output element 18, which in the present example are illustrated as the first and second axle shafts, respectively.The first output element 16 can, for example, be coupled to the left wheel 20, and the second output element 18 can be coupled to the right wheel 22 of the axle assembly 10. In particular, and as further explained below, the drive mechanism 14a can be selectively operated in a variety of operating modes, including a torque-vectoring mode, a propulsion mode (i.e., drive or equivalent torque mode), and a neutral mode, where the torque-vectoring mode can be used to create a torque difference between the first and second output elements 16 and 18.

[0021] The drive mechanism for a torque distribution 14a can comprise a double planetary gear set 30, a drive element 32, a power storage device 34, and a differential assembly 36. The drive mechanism 14a can also include an actuator 150, a control unit or control module 210, and a variety of sensors 214, 216, 218, 220, 222.

[0022] The double planetary gear set 30 can be mounted coaxially with respect to the first and second output elements 16 and 18 and / or the differential assembly 36. The double planetary gear set 30 can comprise a first planetary gear set 40 and a second planetary gear set 42. The first and second planetary gear sets 40 and 42 can have identical gear ratios and can be designed such that one or more of the components of the first planetary gear set 40 are interchangeable with a corresponding component(s) of the second planetary gear set 42.

[0023] The first planetary gear set 40 can comprise a first sun gear 50, a plurality of first planet gears 52, a first ring gear 54, and a first planet carrier 56. The first sun gear 50 can be a general hollow structure that may be arranged concentrically around the first output element 16. The first planet gears 52 can be arranged circumferentially and separately from one another around the first sun gear 50, such that the teeth of the first planet gears 52 mesh with the teeth of the first sun gear 50. Likewise, the first ring gear 54 can be arranged concentrically around the first planet gears 52, such that the teeth of the first planet gears 52 mesh with the teeth of the first ring gear 54. The first ring gear 54 can be rotatably mounted in a gear housing 58, which may be non-rotatably coupled to a differential housing 60 that contains the differential assembly 36.The first planet carrier 56 can have a first carrier body 62 and a plurality of first pins 64, which can be rigidly coupled to the first carrier body 62. The first carrier body 62 can be coupled to the first output element 16, such that the first carrier body 62 and the first output element 16 rotate together. Any suitable means can be used to couple the first carrier body 62 to the first output element 16, including welds and interlocking teeth or splines. Each of the first pins 64 can be received in a corresponding first planet gear 52 and can support the corresponding first planet gear 52 for rotation about a longitudinal axis of the first pin 64.

[0024] The second planetary gear set 42 can comprise a second sun gear 70, a plurality of second planet gears 72, a second ring gear 74, and a second planet carrier 76. The second sun gear 70 can be a general hollow structure that may be arranged concentrically around the first output element 16. The second sun gear 70 can be non-rotatably coupled to the first sun gear 50 (e.g., the first and second sun gears 50 and 70 may be integrally and uniformly shaped). The second planet gears 72 can be arranged circumferentially separate from one another around the second sun gear 70, such that the teeth on the second planet gears mesh with teeth of the second sun gear 70. The second ring gear 74 can be arranged concentrically around the second planet gears 72, such that the teeth of the second planet gears 72 mesh with teeth on the second ring gear 74. The second ring gear 74 can be non-rotatably coupled to the gearbox housing 58.The second planet carrier 76 can have a second carrier body 82 and a plurality of second pins 84, which can be rigidly coupled to the second carrier body 82. The second carrier body 82 can be coupled to a housing or a differential carrier 83 of the differential assembly 36, such that the second carrier body 82 and the differential carrier 83 rotate together. Each of the second pins 84 can be received in a corresponding second planet gear 72 and can support the corresponding second planet gear 72 for rotation about a longitudinal axis of the second pin 84.

[0025] The first and second planetary gear sets 40 and 42 can be aligned together about a common longitudinal axis (i.e. an axis which can extend through the first and second sun gear sets 50 and 70) and can be axially offset from each other along the common longitudinal axis 85.

[0026] The drive element 32 can be any means for providing torque input to the double planetary gear set 30, such as an electric or hydraulic motor, and can be used to drive an input element 86, which transmits torque to a gear input of the first planetary gear set 40. In the example provided, the drive element 32 is an electric motor that is electrically coupled to and configured to receive electrical energy from the power storage device 34. The power storage device 34 can be any suitable type of electrical storage device, such as a battery, a capacitor, a supercapacitor, or a plurality or combination thereof.In the example provided, the input element 86 is rotatable relative to the first ring gear 54 and has a plurality of teeth that mesh with the teeth of a reduction gear 88, which is mounted on an output shaft 90 of the drive element 32. The input element 86 can include a crown gear, which can be rotatably mounted about the first output element 16 and the first planetary gear 40.

[0027] The actuator 150 can be used to control the operating state of the drive mechanism 14a. The actuator 150 can have a shift sleeve 152 that can form the gear input of the first planetary gear 40. The shift sleeve 152 can have a toothed outer surface 154 that engages non-rotatably but axially displaceably with a correspondingly toothed inner surface 156 of the input element 86, a set of first, inner teeth 160 that can engage correspondingly with teeth 162 formed on the first ring gear 54, and a set of second, inner teeth 164 that can engage correspondingly with teeth 166 formed on the second planet carrier 76.

[0028] The control module 210 can be configured to control the operation of the actuator 150, as described below. The control module 210 can be any suitable type of controller, such as a control unit of the vehicle 12 or a separate control unit. The control module 210 can have or communicate with a computer-readable medium or memory circuit (not specifically shown) to store programs and / or information for use by the control module 210. The control module 210 can be electrically coupled to the actuator 150 and the sensors 214, 216, 218, 220, and 222. The control module 210 can be configured to receive signals from the sensors 214, 216, 218, 220, 222 and the actuator 150 and to send control signals to cause the actuator 150 to adjust the position of the switching sleeve 152.

[0029] Sensors 214, 216, 218, 220, and 222 can be any suitable type of sensor for detecting or measuring conditions or parameters of the vehicle 12 or the environment in which the vehicle 12 operates, such as acceleration sensors, speed sensors, proximity sensors, GPS devices, rotation sensors, torque sensors, temperature sensors, or weather sensors. Sensor 214 can be coupled to the drive element 32 or to any suitable component to measure the actual torque (T) output by the drive mechanism 14a. Sensor 216 can be electrically coupled to the power storage device 34 and configured to measure the available system energy (E) in the power storage device 34. Sensor 216 can, for example, be configured to measure the voltage of the power storage device 34.

[0030] Sensor 218 can be coupled to a throttle control (not shown, e.g., an accelerator pedal) or any other component suitable for measuring the torque (τ) requested by the driver. In the provided example, sensor 218 can measure the position of the throttle control. The position of the throttle control can be measured physically, such as with position sensors, or it can be determined from an electrical measurement, such as the voltage output of an electronic (drive-by-wire) throttle control. Sensor 220 can be configured to measure the longitudinal speed (v) of the vehicle 12. The longitudinal speed (v) can be measured using any conventional method, such as by rotations of a calibrated part, GPS, radar, or laser measurements.

[0031] Sensor 222 can be configured to measure the vehicle's lateral instability (s). In the provided example, the lateral instability (s) can be a value ranging from plus one (+1) to minus one (-1), although other ranges or methods for determining instability may be used. If the lateral instability (s) is zero (0), the vehicle can be completely stable (e.g., it experiences neither understeer nor oversteer). If the vehicle experiences understeer, the lateral instability (s) can be a positive number (e.g., between zero and plus one), with plus one indicating maximum understeer. If the vehicle experiences oversteer, the lateral instability (s) can be a negative number (e.g., between zero and minus one), with minus one indicating maximum oversteer.

[0032] It is understood that additional sensors (not shown) can be used to measure further parameters. The control module 210 can also be configured to calculate additional values ​​based on the measured values. The control module 210 can be configured to compare these measured or calculated values ​​with reference or threshold values ​​in a manner that will be discussed below.

[0033] The reference or threshold values ​​may include a first or high-speed threshold (v_1), a second or low-speed threshold (v_2), a traction moment threshold (T_1), a system energy threshold (E_1), a first or low demand threshold (τ_1), a second or high demand threshold (τ_2), and a lateral instability threshold (s_1).

[0034] The high-speed threshold (v_1) can be a value calibrated depending on the vehicle 12. The high-speed threshold (v_1) can be set such that if the vehicle 12 is moving at speeds greater than or equal to the high-speed threshold (v_1), it is considered to be operating at high speed. In the provided example, the high-speed threshold (v_1) can be nine meters per second (9 m / s), although other values ​​can be used. The value of the high-speed threshold (v_1) can also depend on a condition outside of the vehicle 12, such as ambient temperature or weather conditions. For example, if the ambient temperature is below a certain level, or if rain or snow is detected, the high-speed threshold (v_1) can have a different (e.g., lower) value.

[0035] The low-speed threshold (v_2) can be a value calibrated depending on the vehicle 12. The low-speed threshold (v_2) can be a value less than or equal to the high-speed threshold (v_1). The low-speed threshold (v_2) can be set such that if the vehicle 12 is moving at speeds less than or equal to the low-speed threshold (v_2), the vehicle 12 is considered to be operating at a low speed. In the provided example, the low-speed threshold (v_2) can be seven meters per second (7 m / s), although other values ​​can be used. The value of the low-speed threshold (v_2) can also depend on a condition outside of the vehicle 12, such as ambient temperature or weather conditions.For example, if the ambient temperature is below a certain temperature, or if rain or snow is detected, the low-speed threshold (v_2) may be a different (e.g. higher) value.

[0036] The traction torque threshold (T_1) can be a value calibrated depending on the vehicle 12. The traction torque threshold (T_1) can be set such that if the torque produced by the drive mechanism 14a (and / or the torque received by the drive mechanism 14a from the internal combustion engine 120 or a combination thereof) is greater than the traction torque threshold (T_1), switching between the modes of the drive mechanism 14a would be undesirable. The traction torque threshold (T_1) can be set to minimize inconvenience to vehicle occupants 12 during mode switching or to prevent damage to components of the drive mechanism 14a.

[0037] The system energy threshold (E_1) can be a value calibrated depending on the vehicle 12. Under certain conditions, operation in propulsion mode may draw more electrical power than in torque-vectoring mode. Accordingly, the system energy threshold (E_1) can be a value such that if the electrical energy available to the drive mechanism 14a (e.g., from the power storage device 34) is greater than or equal to the system energy threshold (E_1), the amount of available energy can be considered sufficient for operation in propulsion mode. In the provided example, the system energy threshold (E_1) can be forty-five percent (45%) of the full charge of the power storage device 34, although other values ​​can be used.

[0038] The low request threshold (τ_1) can be a value calibrated depending on the vehicle 12. The low request threshold (τ_1) can be a value such that if the driver request for torque is less than or equal to the low request threshold (τ_1), the requested amount of torque is considered to be a low amount of torque. In the provided example, if the driver requests less than or equal to forty-five percent (45%) of the maximum throttle position (e.g., by depressing the accelerator pedal to a corresponding position), the requested torque (τ) is considered to be low, although other values ​​can be used. The value of the low request threshold (τ_1) can also depend on a condition outside of the vehicle 12, such as ambient temperature or weather conditions.For example, if the ambient temperature is below a certain temperature, or if rain or snow is detected, the low request threshold (τ_1) may be a different (e.g. higher) value.

[0039] The high demand threshold (τ_2) can be a value calibrated depending on the vehicle 12. The high demand threshold (τ_2) can be a value greater than or equal to the low demand threshold (v_1). The high demand threshold (τ_2) can be a value such that if the driver's torque demand is greater than or equal to the high demand threshold (τ_2), the requested torque amount is considered to be a high torque amount. In the provided example, if the driver demands more than or equal to sixty percent (60%) of the maximum throttle position (e.g., by depressing the accelerator pedal to a corresponding position), the requested torque (τ) is considered high, although other values ​​can be used. The value of the high demand threshold (τ_2) can also depend on a condition outside of the vehicle 12, such as ambient temperature or weather conditions.For example, if the ambient temperature is below a certain temperature, or if rain or snow is detected, the high demand threshold (τ_2) may be a different (e.g. higher) value.

[0040] The lateral instability threshold (s_1) can be a value calibrated depending on the vehicle 12. The lateral instability threshold (s_1) can be a value such that if the vehicle 12 has a lateral instability (s) of a magnitude less than or equal to the lateral instability threshold (s_1) (e.g., |s| ≤ s_1), the vehicle 12 is considered sufficiently stable. A positive (e.g., understeer) or negative (e.g., oversteer) instability value (s) of a magnitude less than or equal to the instability threshold (s_1) can, for example, be considered sufficiently stable. Alternatively, a range of values ​​can be used. If the lateral instability (s) is greater than or equal to an oversteer threshold (s_2) and less than or equal to an understeer threshold (s_3) (e.g. s_2 ≥ s ≤ s_3), the vehicle 12 can be considered sufficiently stable.In such an example, the amount of over-taxation and the amount of under-taxation that are characteristic of instability can be of different orders of magnitude.

[0041] In addition to the differential housing 60 and the differential carrier 83, the differential assembly 36 may include a means for transmitting torque from the differential carrier 83 to the first and second output elements 16 and 18. The means for transmitting torque may include a first differential output 100 and a second differential output 102. In the particular example provided, the means for transmitting torque includes a differential gear 104 housed in the differential carrier 83, which has a first side bevel gear 106, a second side bevel gear 108, a transverse pin 110, and a plurality of compensating bevel gears 112. The first and second side bevel gears 106 and 108 may be rotatably arranged about an axis of rotation of the differential carrier 83 and may each comprise the first or second output element 100 and 102, respectively.The first output element 16 can be coupled to the first side bevel gear 106 for common rotation, while the second output element 18 can be coupled to the second side bevel gear 108 for common rotation. The transverse pin 110 can generally be mounted on the differential carrier 83 perpendicular to its axis of rotation. The compensating bevel gears 112 can be rotatably mounted on the transverse pin 110 and can mesh with the first and second side bevel gears 106 and 108.

[0042] While the differential assembly 36 is illustrated using bevel pinions and side bevel gears, it is understood that other types of differential mechanisms could be used, including differential mechanisms using helical compensating gears and side bevel gears or planetary gears.

[0043] Optionally, the differential assembly 36 can be coupled to a main or primary drive of the vehicle 12. In the particular example provided, the primary drive of the vehicle comprises an internal combustion engine 120, which is used to drive the differential assembly 36. In this respect, torque produced by the internal combustion engine 120 can be transmitted in a conventional manner to the differential carrier 83 to drive the first and second output elements 16 and 18 (i.e., via the differential carrier 83 and the differential gear 104). In this way, the drive element 32 can serve as an add-on to the primary drive of the vehicle 12, so that if additional torque is simultaneously generated by the drive element 32, the additional torque is superimposed on the first and second output torques induced by the primary drive, as will be further explained below.

[0044] In torque-vectoring mode, the shift sleeve 152 can be positioned in a first position to couple the input element 86 to the first ring gear 54 (via an engagement of the set of first, inner teeth 160 with the teeth 162 on the first ring gear 54), so that the input element 86, the shift sleeve 152, and the first ring gear 54 rotate together. It is understood that the set of second, inner teeth 164 can be disengaged from the teeth 166 on the second planet carrier 76 when the shift sleeve 152 is in the first position.

[0045] In the first position, the drive element 32 can be selectively activated. When the drive element 32 is activated (i.e., when the output shaft 90 of the drive element 32 rotates in the example provided), the drive element 32, the reduction gear 88, the input element 86, and the shift sleeve 152 can work together to apply torque to the first ring gear 54 of the first planetary gear set 40. The torque received by the first ring gear 54 is transmitted via the first planet gears 52 and the first planet carrier 56 to the first output element 16, while an opposing back pressure is applied to the first sun gear 50, causing the first sun gear 50 to rotate in a direction opposite to that of the first planet carrier 56. Rotation of the first sun gear 50 causes a corresponding rotation of the second sun gear 70, thereby driving the second planet gears 72.Because the second ring gear 74 is rotatably mounted on the gearbox housing 58, a rotation of the second planet gears 72 causes a rotation of the second planet carrier 76 in a direction opposite to the direction of rotation of the first planet carrier 56. Accordingly, the magnitude of the rotational force (i.e., the torque) transmitted from the second planet carrier 76 to the differential carrier 83 (and through the differential assembly 36 to the second output element 18) is equal to, but opposite to, the magnitude of the rotational force (i.e., the torque) transmitted from the first planet carrier 56 to the first output element 16.

[0046] Consequently, the respective torques induced by the drive element 32 at the first and second output elements 16 and 18 are opposite in direction. Furthermore, since the first and second planetary gear units 40 and 42 are coupled via the differential assembly 36, the magnitude of the induced torques at the first and second output elements 16 and 18 is essentially the same. For example, if a positive torque is transmitted to the first output element 16 (via rotation of the output shaft 90 of the drive element 32 in a first direction of rotation), an equal negative torque is transmitted to the second output element 18. Similarly, if a negative torque is transmitted to the first output element 16 (via rotation of the output shaft 90 of the drive element 32 in a second direction of rotation opposite to the first direction of rotation), an equal positive torque is transmitted to the second output element 18.In other words, the drive mechanism 14a could be used to produce a torque difference between the first and second differential outputs 100 and 102, which is transmitted to the left and right wheels 20 and 22 respectively by the first and second output elements 16 and 18 respectively.

[0047] In superstructures that have the optional primary drive (i.e. the internal combustion engine 120 in the illustrated example), and in which the drive element 32 is activated when torque is transferred from the primary drive to the differential assembly 36, the torque transferred by the drive mechanism 14a will act as an offset torque superimposed on the input torque transferred to the axle assembly 10 from the primary drive.In other words, the input torque from the primary drive is distributed via the differential assembly 36, so that a first drive torque is applied to the first output element 16 via the first differential output 100 and a second drive torque is applied to the second output element 18 via the second differential output 102, while an additional torque induced by the drive element 32 is distributed via the double planetary gear set 30, so that a first vectoring torque is applied to the first output element 16 and a second vectoring torque (which is equal to and opposite to the first vectoring torque in the provided example) is applied to the second output element 18 (via the differential assembly 36).The pure torque acting on the first output element 16 is the sum of the first drive torque and the first vectoring torque, while the pure torque acting on the second output element 18 is the sum of the second drive torque and the second vectoring torque.

[0048] For example, the drive mechanism 14a could subtract torque from the left wheel 20 and add a corresponding torque to the right wheel 22 when the motorized vehicle 12 turns left, and could subtract torque from the right wheel 22 and add a corresponding torque to the left wheel 20 when the motorized vehicle 12 turns right, in order to improve the cornering behavior of the vehicle 12 and reduce its turning radius.

[0049] Experts understand that the design of the double planetary gear 30 causes the first and second sun gears 50 and 70 to experience the highest rotational speed, while the first ring gear 54 rotates at a slightly slower speed, and the first and second planet carriers 56 and 76 rotate at a speed slower than that of the first ring gear 54. In this way, a favorable gear ratio, such as a ratio of approximately 1:1.5 to approximately 1:2.0 between the first ring gear 54 and the first output element 16, can be achieved. Consequently, the size of the gears in the double planetary gear 30 can be reduced. For example, the diameter of the first and second planet gears 52 and 72 can be as small as approximately 30 mm. Thus, the size of the double planetary gear 30 can be reduced, and the drive mechanism 14a can be made compact and lightweight.

[0050] The drive element 32 can be activated (e.g., automatically or on demand) when the vehicle 12 turns. When driving straight ahead, the drive element 32 may not be activated to allow the wheels 20 and 22 to rotate freely. Alternatively, in the configuration where the optional primary drive (i.e., internal combustion engine 120) transmits torque to the differential assembly 36, the vehicle 12 can be driven forward by the internal combustion engine 120. In such a situation, the differential assembly 36, which receives the input torque from the internal combustion engine 120, transmits substantially equal torque to the first output element 16 and the second output element 18. In turn, substantially equal torque is transmitted to the first and second planetary carriers 56 and 76, which rotate at substantially the same speed.As a consequence of the identical planetary gear sets 40 and 42, there will be no relative movement between the first and second ring gears 54 and 74, meaning that almost no action or torque will be transmitted to them. In other words, neither the first ring gear 54 nor the second ring gear 74 will rotate. Consequently, the output shaft 90 of the drive element 32 will not move, and losses during straight-line travel will be minimized.

[0051] While the input element 86 has been illustrated and described as engaging directly with the reduction gear 88, it is understood that one or more reduction stages could be arranged between the input element 86 and the reduction gear 88, or that the input element 86 could be driven directly by the drive element 32.

[0052] In the forward mode, the shift sleeve 152 can be positioned in a second position to couple the input element 86 to the second planet carrier 76 (via an engagement of the set of second, inner teeth 164 with the teeth 166 on the second planet carrier 76), so that the torque provided by the drive element 32 is input to the differential carrier 83 and applied to the first and second output elements 16 and 18 via the differential assembly 36. It is understood that the set of first, inner teeth 160 on the shift sleeve 152 can be disengaged from the teeth 162 on the first ring gear 54 when the shift sleeve 152 is in the second position. It is also understood that the rotational force provided by the drive element 32 is used as a driving force when the drive mechanism 14a is operated in the propulsion mode to drive (or assist in driving) the vehicle 12 forward.It is also understood that the torque provided by the drive element 32, where the optional primary drive (i.e., internal combustion engine 120) is included and the drive element 14a is operated in propulsion mode, complements the torque provided by the internal combustion engine 120 to the differential carrier 83 to assist in propelling the vehicle 12 forward.

[0053] In neutral mode, the shift sleeve 152 can disengage the input element 86 from the first ring gear 54 and the second planet carrier 76, so that the input element 86 is disengaged from the first planetary gear 40, the second planetary gear 42, and the differential carrier 83. In the provided example, the shift sleeve 152 can be positioned in a third position between the first and second positions, such that the sets of first and second inner teeth 160 and 164 are axially arranged between and disengaged from the teeth 162 on the first ring gear 54 and the teeth 166 on the second planet carrier 76. Accordingly, positioning the shift sleeve 152 in the third position decouples the drive element 32 from the first planetary gear 40, the second planetary gear 42, and the differential carrier 83.

[0054] With reference to Fig. 2. A further axle assembly (e.g., drive module) constructed according to the teaching of the present disclosure is generally characterized by the reference numeral 10b. The axle assembly 10b can be related to the axle assembly 10 of Fig. 1 generally similar, except as noted herein. In this example, the axle assembly 10b comprises a drive mechanism 14b that can be selectively operated in a variety of operating modes, including a torque-vectoring mode, a propulsion mode (high-speed propulsion, drive, or equivalent torque mode), a neutral mode, and a low-speed propulsion mode. The torque-vectoring drive mechanism 14b can be distinguished from the torque-vectoring drive mechanism 14a by Fig. 1. Structurally similar, except that the shift sleeve 152b may have a third set of internal teeth 170 which may selectively engage with the teeth 172 of a toothed element 174 coupled to the first and second sun gears 50 and 70 for common rotation. The third set of internal teeth 170 does not engage with any other structure when the drive mechanism 14b is operated in the torque-vectoring, driven, and neutral modes, and as such, the operation of the drive mechanism 14b is essentially the same as the operation of the drive mechanism 14a of Fig. 1 similar in these modes.

[0055] In the low-speed propulsion mode, the shift sleeve 152b can be positioned in a fourth position to couple the input element 86 to the first and second sun gears 50 and 70 (via the engagement of the set of third, inner teeth 170 with the teeth 172 on the element 174), so that the input element 86, the shift sleeve 152b, the element 174, and the first and second sun gears 50 and 70 rotate together. In this mode, the second planetary gear 42 is used as a reduction gear, causing the second planet carrier 76 to rotate at a speed lower than the speed of the second sun gear 70. It is understood that the sets of first and second, inner teeth 160 and 164 can be disengaged from the teeth 162 on the first ring gear 54 and the teeth 166 on the second planet carrier 76 when the shift sleeve 152b is in the fourth position.

[0056] Experts understand that torque is introduced at different points in the double planetary gear set 30 when the drive mechanism 14b is operated in the high-speed and low-speed high-speed modes. In this respect, torque is introduced at the second planet carrier 76 in the high-speed high-speed mode and at the first and second sun gears 50 and 70 in the low-speed high-speed mode. Accordingly, it is understood that the differential carrier 83 will rotate at a slower speed (at a given rotational speed of the output shaft 90 of the drive element 32) in the low-speed high-speed mode compared to the high-speed high-speed mode.In this respect, when the drive mechanism 14b is operated in low-speed propulsion mode, the rotation of the first and second sun gears 50 and 70 causes a corresponding rotation of the second planet gears 72, which in turn drives the rotation of the second planet carrier 76 and the differential carrier 83. In other words, a reduction gear is provided between the rotary input (i.e., element 174) and the differential carrier 83 when the drive mechanism 14b is operated in low-speed propulsion mode, and no reduction gear is provided between the rotary input (i.e., the second planet carrier 76) and the differential carrier 83 when the drive mechanism 14b is operated in high-speed propulsion mode.

[0057] The axial dimensions of the shift sleeve 152 and the width and spacing of several sets of teeth can be selected such that at most one of the sets of inner teeth 160, 164, and 170 is permitted to engage simultaneously with the corresponding teeth 162, 166, and 172, respectively. Additionally or alternatively, the pitch circle diameters of the meshing sets of teeth can be dimensioned differentially to allow certain teeth to slide over other teeth where engagement of these teeth is not desired. For example, the pitch circle diameter of the set of second inner teeth 164 is larger than the pitch circle diameter of the set of third inner teeth 170, so that the set of second inner teeth 164 can axially pass over the teeth 172 on the element 174, which is rotatably coupled to the first and second sun gears 50 and 70.

[0058] Similar to the structure of Fig. As previously described, the switching element (e.g., actuator 150) can comprise the switching sleeve 152b, which is rotatably coupled to the crown gear (input element 86b). Furthermore, the switching element can comprise the radially extending tooth structure (second, inner teeth 164) arranged on the switching sleeve 152b in an inwardly radial direction and configured to engage with the matching tooth structure (teeth 166) on the outer surface of the differential carrier 83. The switching sleeve 152b can slide along the crown gear 86b in an axial direction. By moving the switching sleeve 152b toward the differential assembly 36, the second, inner teeth 164 of the switching sleeve 152b can engage with the matching tooth structure 166 on the differential carrier 83. In this way, the drive mechanism for a torque distribution 14b can be operated in the propulsion mode for high speed.When the shift sleeve 152b is moved away from the differential assembly 36, the second, inner teeth 164 of the shift sleeve 152b disengage from the teeth 166 on the outer surface of the differential carrier 83. In this way, the drive mechanism 14b will be in a neutral mode, as it does not induce any torque on the differential assembly 36.

[0059] One advantage of this design is that it can be modular. This means that the assembly can be shaped as a module that can easily be added to a differential in an existing transmission.

[0060] The switching element or switching sleeve 152, 152b in each of the drive mechanisms 14a, 14b can be moved axially by any desired actuator 150, including conventional shift fork actuators of the type commonly used in distribution gearboxes, or the actuator described in US patent application publication US 2014 / 0364264A1 with reference to the Fig. 4, Fig. 5 to Fig. 6 of US patent application publication US 2014 / 0364264A1. It is also understood that one or more synchronization devices may be incorporated in the shift sleeve 152, 152b to allow the shift sleeve 152, 152b to be driven (e.g., via the first ring gear 54 or the second planet carrier 76) before the activation of the drive element 32, so that the rotational speed of the shift sleeve 152, 152b matches the rotational speed of the component to which the shift sleeve 152, 152b is to be rotationally coupled.

[0061] In the Fig. 3 and Fig. Figure 4 of the drawings illustrates a part of a further axle assembly 10c (e.g., drive module) which is constructed in accordance with the teaching of the present disclosure. The axle assembly 10c can have a drive mechanism for a torque distribution 14c, which is similar to the drive mechanism for a torque distribution 14a. Fig. 1 is somewhat similar, except as shown and described below. In one aspect, the drive element 32c and a clutch mechanism 2000 can work together to alternately provide torque, which is used by the differential assembly 36c as a propulsive force or for the double planetary gear 30 for torque vectoring control of the first and second output elements 16c and 18c.

[0062] The drive element 32c can comprise any type of motor, such as a DC electric motor 2004, and can have an output shaft 2006 that can be selectively operated to provide torque to a reduction gear 2010. The reduction gear 2010 can have a first compensating bevel gear 2012, which can be mounted on the output shaft 2006 for common rotation, and a second compensating bevel gear 2014, which can be mounted on an intermediate shaft 2016 for common rotation. The intermediate shaft 2016 can be arranged along an intermediate axis 2020, which is generally parallel to an output shaft 2022 about which the output shaft 2006 of the motor 2004 rotates. The intermediate axis 2020 and the intermediate axis 2022 can be parallel to an axis 2024, around which the differential assembly 36c and the first and second output elements 16c and 18c rotate.In the specific example provided, the intermediate shaft 2020, the output shaft shaft 2022, and the shaft 2024 are arranged in a common plane, but it is understood that either one or both of the intermediate shaft 2024 and the output shaft shaft 2022 may be positioned differently. Furthermore, it is understood that one or more shafts 2020 and 2022 may be spatially separated from the shaft 2024, such that one of the shafts 2020, 2022, and 2024 will not lie in a common plane. While the reduction gear 2010 has been described and illustrated as having only one pair of gears, it is understood that the reduction gear may alternatively include additional gears, which may be arranged in a gear train between the first differential bevel gear 2012 and the second differential bevel gear 2014.

[0063] With particular reference to Fig. 4. The intermediate shaft 2016 can have a first shaft stub 2030, a second shaft stub 2032, and a drive part 2034, which can be arranged between the first and second shaft stub 2030 and 2032. The drive part 2034 can have a plurality of external splines or teeth that can mesh with a plurality of internal splines or teeth formed on a drive element 2038. A first intermediate output gear 2040 can be rotatably mounted on the first shaft stub 2030, and a second intermediate output gear 2042 can be rotatably mounted on the second shaft stub 2032. Bearings 2050 and 2052 can be mounted accordingly between the first and second shaft stub 2030 and 2032 and the first and second intermediate output gears 2040 and 2042.Thrust bearings 2054 can be arranged at various locations along the length of the intermediate shaft 2016 to promote a relative rotation between the drive element 2038 and the first and second intermediate output gears 2040 and 2042.

[0064] The first intermediate output gear 2040 can mesh with a ring gear 2056 of the differential assembly 36c. The ring gear 2056 can be rigidly coupled to the differential carrier 83c for common rotation. It is understood that a rotation of the first intermediate output gear 2040 can cause a corresponding rotation of the ring gear 2056 and the differential carrier 83c, and that a rotation of the differential carrier 83c can similarly cause a corresponding rotation of the first intermediate output gear 2040. The second intermediate output gear 2042 can mesh with the input element 86c. The input element 86c can be integrally formed with the first ring gear 54c. Accordingly, a rotation of the second intermediate output gear 2042 can cause a corresponding rotation of the input element 86c and the first ring gear 54c.It is understood that the hollow gear 2056 can be driven by an optional primary drive similar to the combustion engine 120 (. Fig. 1) can be coupled and the inclusion of a primary drive in the axle assembly 10c will serve to be operated in a similar manner as if the primary drive were in the axle assembly 10 ( Fig. 1) is included.

[0065] The clutch mechanism 2000 can be used to control the operation of the drive mechanism 14c in a neutral state (shown), a propulsion mode (e.g., drive or equal-torque mode), or a torque-vectoring mode. The clutch mechanism 2000 can have a clutch sleeve 2060 with a set of inner teeth that can mesh with a set of outer teeth formed on the drive element 2038. Accordingly, a rotation of the intermediate shaft 2016 causes a corresponding rotation of the clutch sleeve 2060. A first set of clutch teeth 2070 can be formed on the first intermediate output gear 2040, and a second set of clutch teeth 2072 can be formed on the second intermediate output gear 2042.The coupling sleeve 2060 can be displaced axially along the intermediate axis 2020 so that the set of inner teeth formed on the coupling sleeve 2060 engages with the first set of coupling teeth 2070 (to couple the first intermediate output gear 2040 on the intermediate shaft 2016 for common rotation), or so that the set of inner teeth formed on the coupling sleeve 2060 engages with the second set of coupling teeth 2072 (to couple the second intermediate output gear 2042 on the intermediate shaft 2016 for common rotation), or so that the set of inner teeth formed on the coupling sleeve 2060 engages neither with the first set of coupling teeth 2070 nor with the second set of coupling teeth 2072 (so that neither the first nor the second intermediate output gear 2040 and 2042 is coupled to the intermediate shaft 2016 for a common rotation).

[0066] In the provided particular example, a coupling fork 2090 is used to control the axial position of the coupling sleeve 2060. While not explicitly shown, the coupling fork 2090 can be moved by any type of actuator to axially move the coupling sleeve 2060 along the intermediate axis 2020. The actuator (not shown) can be of a type similar to actuator 150. Fig. 1 and Fig. 2. The actuator (not shown) can be controlled by a control module (not shown) which is part of control module 210 of the Fig. 1 and Fig. 2 may be similar. The control module (not shown) can receive input signals from sensors (not shown) similar to sensors 214, 216, 218, 220, 222 of the Fig. 1 and Fig. There can be 2.

[0067] The operation of the clutch mechanism 2000 in a first mode (i.e., a forward mode) can couple the first intermediate output gear 2040 to the intermediate shaft 2016 (via the clutch sleeve 2060) to drive the ring gear 2056 of the differential assembly 36c. As is understood, a rotation of the ring gear 2056 drives the differential carrier 83c and the transverse pin 110 for rotation about the output axis 2024. The differential bevel gears 112 can be rotatably mounted on the transverse pin 110 and can mesh with the first and second side bevel gears 100 and 102. The first side bevel gear 100 engages with the first output element 16c, and the second side bevel gear 102 engages with the second output element 18c.In this mode, the double planetary gear 30 does not affect the operation of the differential assembly 36c, and as such, the differential assembly 36c provides torque to the first and second output elements 16c and 18c in the manner of a standard open differential assembly.

[0068] Operating the coupling mechanism 2000 in a second mode (i.e., in torque-vectoring mode), it can couple the second intermediate output gear 2042 to the intermediate shaft 2016 (via the coupling sleeve 2060) to drive the input element 86c and the first ring gear 54c of the double planetary gear set 30. In this embodiment, torque is output from the first planetary gear set 40c to the differential carrier 83c (via the first planetary carrier 56c) and torque is output from the first planetary gear set 42c to the second output element 18c (via the second planetary carrier 76c). Since the second output element 18c is non-rotatably coupled to the second side bevel gear 102, it is understood that the second planetary carrier 76c is also drive-coupled to the second side bevel gear 102.Experts infer from this disclosure that the double planetary gear unit 30 can be used to apply an equal but opposite torque difference to the first and second output elements 16c and 18c, and that the amount of torque applied to a particular output element depends on the direction in which the motor 2004 is operated.

[0069] With additional reference to Fig. Figure 5 illustrates a flowchart of a logic routine 510 for switching between modes of a drive mechanism for torque distribution, such as the drive mechanisms for torque distribution 14a, 14b or 14c ( Fig. 1, Fig. 2, Fig. 3 to Fig. 4), which are described above. The logic routine 510 can be controlled by the control module 210 ( Fig. 1 and Fig. 2) can be used and can be programmed in the control module 210 or on the computer-readable medium (not shown) accessible through the control module 210. In this way, the control module 210 can follow the steps of the logic routine 510 when controlling the actuator 150 ( Fig. 1 and Fig. 2).

[0070] At step 514 of the logic routine 510, the control module 210 can control the sensors 214, 216, 218, 220, 222 ( Fig. 1 and Fig. 2) and check the actuator 150 or receive input information from it. This input information can be in the form of electrical signals sent, for example, by sensors 214, 216, 218, 220, 222 and actuator 150 to the control module 210. The input information can also include values ​​stored in the control module 210 or in a computer-readable medium, or it can be calculated, for example, based on measured values, such as in a lookup table.The input information can include the actual torque output (T), the driver-requested torque (τ), the available system energy (E), the longitudinal speed (V), the lateral vehicle instability (s), the high-speed threshold (v_1), the low-speed threshold (v_2), the traction torque threshold (T_1), the system energy threshold (E_1), the low request threshold (τ_1), the high request threshold (τ_2), the lateral instability threshold (s_1), and the current mode of the drive mechanism 14a, 14b, or 14c (e.g., high-speed propulsion, low-speed propulsion, torque vectoring, or neutral). After acquiring the input values, the logic routine 510 can proceed to step 518. It is understood that the control module 210 can also look up, calculate, or acquire specific input values ​​as needed, instead of acquiring all input values ​​during step 514.

[0071] At step 518, the control module 210 can determine the mode of the drive mechanism 14a, 14b, 14c (e.g., propulsion mode, torque vectoring mode, or neutral mode). If the drive mechanism 14a, 14b, 14c is in propulsion mode, the logic routine 510 can proceed to step 522. If the drive mechanism 14a, 14b, 14c is not in propulsion mode, the logic routine 510 can proceed to step 526.

[0072] At step 522, the control module 210 can check whether a first set of conditions 528 is met. The first set of conditions 528 can include: if the torque (τ) requested by the driver is less than or equal to the low-speed threshold (τ_1); and if the longitudinal speed (v) is greater than or equal to the high-speed threshold (v_1). The first set of conditions 528 can also include: if the actual torque output (T) is greater than or equal to the traction torque threshold (T_1). If any of the conditions of the first set of conditions 528 is not met, the logic routine 510 can return to step 514. If all conditions of the first set of conditions 528 are met, the logic routine 510 can proceed to step 530. In the provided example, the longitudinal speed (v) can be considered to be less than or equal to the high-speed threshold (v_1) if the longitudinal speed (v) is zero (e.g.,The vehicle 12 is stopped) or is negative (e.g., the vehicle 12 is moving in reverse). In an alternative configuration, the absolute value of the longitudinal speed (v) can be used, so that if the vehicle 12 is moving forward or backward at a speed greater than or equal to the high-speed threshold (v_1), the longitudinal speed of the vehicle 12 (v) is considered to be greater than or equal to the high-speed threshold (v_1).

[0073] At step 530, the control module 210 can send a control signal to the actuator 150 to switch the drive mechanism 14a, 14b, 14c into torque vectoring mode. After switching the drive mechanism 14a, 14b, 14c into torque vectoring mode, the logic routine 510 can return to step 514.

[0074] Returning to step 518, if the drive mechanism 14a, 14b, 14c is not in propulsion mode, the logic routine 510 can proceed to step 526. At step 526, the control module 210 can check whether a second set of conditions 532 is satisfied. The second set of conditions 532 can include: if the longitudinal speed (v) is less than or equal to the low-speed threshold (v_2); and if the absolute value of the lateral instability (s) is less than or equal to the lateral instability threshold (s_1). Since the absolute value of the lateral instability (s) is used, the vehicle is considered stable if the amount of oversteer or the amount of understeer is less than or equal to a predetermined amount specified by the lateral instability threshold (s_1).Alternatively, the instability element of the second set of conditions 532 can have a range of values ​​such that the lateral instability (s) is greater than or equal to the overdrive threshold (s_2) and less than or equal to the underdrive threshold (s_3). In such an example, the amount of overdrive and the amount of underdrive that characterize instability can be different values. The second set of conditions 532 can also include: if the available system energy (E) is greater than or equal to the system energy threshold (E_1). If all conditions of the second set of conditions 532 are met, logic routine 510 can proceed to step 534. If any of the conditions of the second set of conditions 532 are not met, logic routine 510 can proceed to step 538.

[0075] At step 534, the control module 210 can send a control signal to the actuator 150 to switch the drive mechanism 14a, 14b, 14c into propulsion mode. After the drive mechanism 14a, 14b, 14c has switched into propulsion mode, the logic routine 510 can return to step 514.

[0076] Returning to step 526, if one of the conditions of the second set of conditions 532 is not met, logic routine 510 can proceed to step 538. At step 538, control module 210 can check whether a third set of conditions 540 is met. The third set of conditions 540 can include the following: if the torque (τ) requested by the driver is greater than or equal to the high request threshold (τ_2). If all conditions of the third set of conditions 540 are met, logic routine 510 can proceed to step 534. If one of the conditions of the third set of conditions 540 is not met, logic routine 510 can proceed to step 542.

[0077] At step 542, the control module 210 can check whether the drive mechanism 14a, 14b, 14c is in torque vectoring mode. If the drive mechanism 14a, 14b, 14c is in torque vectoring mode, the logic routine 510 can return to step 514. If the drive mechanism 14a, 14b, 14c is not in torque vectoring mode (e.g., in neutral mode), the logic routine 510 can proceed to step 522.

[0078] During operation, if the drive mechanism 14a, 14b, 14c is not already in propulsion mode, the control module 210 can be configured to switch the drive mechanism 14a, 14b, 14c into propulsion mode only if either the second or the third set of conditions 532, 540 is met. For example, if the torque requirement is high (τ ≥ τ_2), or if the vehicle 12 is operated at low speeds (V ≤ v_2), the vehicle is stable (|s| ≤ s_1), and the available energy is sufficient (E ≥ E_1). This allows the drive mechanism 14a, 14b, 14c to be pre-positioned and prepared to provide the propulsive torque at the wheels 20, 22 to accelerate the vehicle 12 when torque vectoring is generally less desired, and the energy storage device has sufficient energy available to operate the drive mechanism 14a, 14b, 14c in propulsion mode.This also makes it possible to operate the drive mechanism 14a, 14b, 14c in propulsion mode when the driver requests a predetermined high level of torque regardless of speed, energy or instability.

[0079] If the drive mechanism 14a, 14b, 14c is not already in torque-vectoring mode, the control module 210 can be configured to switch the drive mechanism 14a, 14b, 14c to torque-vectoring mode when the first set of conditions 528 is met. For example, if the torque requirement is low (τ ≤ τ_1), the vehicle 12 is operating at high speeds (V ≥ v_1), and the torque output by the drive mechanism 14a, 14b, 14c is below a threshold (T ≤ T_1). This allows the drive mechanism 14a, 14b, 14c to be pre-positioned and prepared to provide torque vectoring to improve handling and lateral behavior. In this way, the torque vectoring mode can become the default mode for high speeds and the drive mechanism 14a, 14b, 14c can be configured to remain in torque vectoring mode until either the second or third set of conditions 532, 540 is met.

[0080] With additional reference to Fig. Figure 6 illustrates a flowchart of a second logic routine 610 for switching between modes of a drive mechanism for a torque distribution that has a low-speed propulsion mode, such as drive mechanism 14b. The second logic routine 610 can be linked to logic routine 510 ( Fig. 5) be similar, except as illustrated and described below.

[0081] In step 614, the control module 210 ( Fig. 1 and Fig. 2) similar to step 514 ( Fig. 5) the antennae 214, 216, 218, 220, 222 ( Fig. 1 and Fig. 2) and the actuator 150 ( Fig. 1 and Fig. 2) Check or record input information from it. After recording the input values, logic routine 610 can proceed to step 618.

[0082] At step 618, the control module 210 can determine the mode of the drive mechanism 14b (e.g., high-speed propulsion mode, low-speed propulsion mode, torque vectoring mode, or neutral mode). If the drive mechanism 14b is in high-speed propulsion mode, the logic routine 610 can proceed to step 622. If the drive mechanism 14b is not in high-speed propulsion mode, the logic routine 610 can proceed to step 624.

[0083] In step 622, the control module 210 can check whether a first set of conditions 628 is similar to step 522 ( Fig. 5) is fulfilled. The first set of conditions 628 can be similar to the first set of conditions 528 ( Fig. 5) If one of the conditions of the first set (Conditions 628) is not met, the logic routine 610 can return to step 614. If all conditions of the first set (Conditions 628) are met, the logic routine 610 can continue at step 630.

[0084] At step 630, the control module 210 can send a control signal to the actuator 150 to switch the drive mechanism 14b into torque vectoring mode. After the drive mechanism 14b has switched to torque vectoring mode, the logic routine 610 can return to step 614.

[0085] Returning to step 618, if the drive mechanism 14b is not in high-speed propulsion mode, logic routine 610 can proceed to step 624. At step 624, the control module 210 can check whether the drive mechanism 14b is in low-speed propulsion mode. If the drive mechanism 14b is not in low-speed propulsion mode, logic routine 610 can proceed to step 626. If the drive mechanism 14b is in low-speed propulsion mode, logic routine 610 can proceed to step 638.

[0086] In step 626, the control module 210 can check whether a second set of conditions 632 similar to step 526 exists ( Fig. 5) is fulfilled. The second set of conditions 632 can be similar to the second set of conditions 532 ( Fig. 5) If all conditions of the second set (Conditions 632) are met, the logic routine 610 can proceed to step 634. If one of the conditions of the second set (Conditions 632) is not met, the logic routine 610 can proceed to step 638.

[0087] At step 634, the control module 210 can send a control signal to the actuator 150 to switch the drive mechanism 14b to the low-speed propulsion mode. After switching the drive mechanism 14b to the low-speed propulsion mode, the logic routine 610 can return to step 614.

[0088] Returning to step 626, if one of the conditions of the second set of conditions 632 is not met, the logic routine 610 can continue at step 638. At step 638, the control module 210 can check whether a third set of conditions 640 is similar to step 538 ( Fig. 5) is fulfilled. The third set of conditions 640 can be similar to the third set of conditions 540 ( Fig. 5) If one of the conditions of the third set (Conditions 640) is not met, the logic routine 610 can proceed to step 642. If all conditions of the third set (Conditions 640) are met, the logic routine 610 can proceed to step 644.

[0089] In step 642, the control module 210 can check whether the drive mechanism 14b is in torque vectoring mode similar to step 542 ( Fig. 5). If the drive mechanism 14b is in torque vectoring mode, logic routine 610 can return to step 614. If the drive mechanism 14b is not in torque vectoring mode (e.g., in low-speed propulsion mode or neutral mode), logic routine 610 can proceed to step 622.

[0090] Returning to step 638, if all conditions of the third set (conditions 640) are met, the logic routine 610 can proceed to step 644. At step 644, the control module 210 can send a control signal to the actuator 150 to switch the drive mechanism 14b to high-speed propulsion mode. After switching the drive mechanism 14b to high-speed propulsion mode, the logic routine 610 can return to step 614.

[0091] If the drive mechanism 14b is not already in high-speed propulsion mode during operation, the control module 210 can be configured to switch the drive mechanism 14b to high-speed propulsion mode only when the third set of conditions 640 is met. For example, if the torque requirement is high (τ ≥ τ_2), this also allows the drive mechanism 14b to operate in high-speed propulsion mode when the driver requests a predetermined high level of torque, regardless of vehicle speed, energy, or instability.

[0092] If the drive mechanism 14b is not already in low-speed propulsion mode, the control module 210 can be configured to switch the drive mechanism 14b to low-speed propulsion mode only when the second set of conditions 632 is met. For example, when the vehicle 12 is operating at low speeds (v ≤ v_2), the vehicle is stable (|s| ≤ s_1), and the available energy is sufficient (E ≥ E_1). This allows the drive mechanism 14b to be pre-positioned and prepared to provide the propulsive torque at the wheels 20, 22 to accelerate the vehicle 12 when torque vectoring is generally less desired (e.g., the vehicle is laterally stable), speeds are low, and the energy storage device has sufficient energy available to operate the drive mechanism 14b in low-speed propulsion mode.

[0093] If the drive mechanism 14b is not already in torque-vectoring mode, the control module 210 can be configured to switch the drive mechanism 14b to torque-vectoring mode when the first set of conditions 628 is met. For example, if the torque requirement is low (τ ≤ τ_1), the vehicle 12 is operating at high speeds (V ≥ v_1), and the torque output by the drive mechanism 14b is below a threshold (T ≤ T_1). This allows the drive mechanism 14b to be pre-positioned and prepared to provide torque vectoring to improve handling and lateral behavior. In this way, torque vectoring mode can be the default mode for high speeds, and the drive mechanism 14b can be configured to remain in torque vectoring mode until either the second or third set of conditions 632, 640 is met.

[0094] In this application, including the definitions below, the term "module" or "control unit" may be replaced by the term "circuit". The term "module" may refer to, be part of, or comprise: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a processor circuit (shared, dedicated, or grouped) that executes code; a memory circuit (shared, dedicated, or grouped) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionalities; or a combination of some or all of the above, as in a system-on-a-chip.

[0095] The module may have one or more interface circuits. In some examples, the interface circuits may have wired or wireless interfaces that connect to a local area network (LAN), the internet, a wide area network (WAN), or combinations thereof. The functionality of each particular module of this disclosure may be distributed across multiple modules connected via interface circuits. Multiple modules may, for example, enable load balancing. In another example, a server module (also known as a remote or cloud module) may perform some functions on behalf of a client module.

[0096] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuit" encompasses a single processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" encompasses a processor circuit that, in combination with other processor circuits, executes some or all of the code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on discrete chips, multiple processor circuits on a single chip, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above.The term "shared memory circuit" refers to a single memory circuit that stores some or all of the code from multiple modules. The term "group memory circuit" refers to a memory circuit that, in combination with other memory, executes some or all of the code from one or more modules.

[0097] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium used here does not encompass ephemeral electrical or electromagnetic signals transmitted through a medium (e.g., on a carrier wave); the term computer-readable medium can therefore be considered material and non-ephemeral. Non-restrictive examples of a non-ephemeral, material computer-readable medium are non-volatile memory circuits (e.g., a flash memory circuit, a erasable programmable read-only memory circuit, or a read-only mask memory circuit), volatile memory circuits (e.g., a static random-access memory circuit or a dynamic random-access memory circuit), magnetic storage media (e.g., analog or digital magnetic tape or a hard disk drive), and optical storage media (e.g.,a CD, a DVD or a Blu-ray Disc).

[0098] The apparatus and methods described in this application can be implemented in whole or in part by a specialized computer formed by configuring a general-purpose computer to perform one or more specific functions expressed in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through routine work by a qualified technician or programmer.

[0099] Computer programs contain processor-executable instructions stored on at least one non-perishable, physical, computer-readable medium. Computer programs may also contain or rely on stored data. Computer programs may include a basic input / output system (BIOS) that interacts with the computer's hardware for a specific purpose, device drivers that interact with specific computer components for a specific purpose, one or more operating systems, user applications, background services and applications, etc.

[0100] Computer programs can contain: (i) descriptive text that needs to be parsed, such as HTML (Hypertext Markup Language) or XML (Extensible Markup Language), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. Source code can be written as an example using the syntax of languages ​​including C, C++, C#, Objective-C, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5, Ada, ASP (active server-side pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, and Python®.

[0101] It is understood that the preceding description is merely exemplary and is in no way intended to limit the present disclosure, its application, or uses. While specific examples have been described in the specification and illustrated in the drawings, a person skilled in the art understands that various modifications can be made and equivalents can be replaced by elements thereof without departing from the scope of the present disclosure, as defined in the claims. Furthermore, the mixing and matching of features, elements, and / or functions between the various examples is expressly permitted, even if it is not explicitly shown or described, so that a person skilled in the art would understand from this disclosure that features, elements, and / or functions of one example can be incorporated into another example unless previously described otherwise.Furthermore, many modifications can be made to adapt a particular situation or material to the teaching of the present disclosure without departing from its essential scope. Therefore, it is intended that the present disclosure is not limited to the specific examples illustrated by the drawings and described in the specification as the best mode currently considered for carrying out the teaching of the present disclosure, but rather that the scope of the present disclosure will include all embodiments that fall within the foregoing description and the accompanying claims.

Claims

[1] Method for controlling the power transmission in a vehicle (12) to a set of vehicle wheels (20, 22), the method comprising: Providing a drive module (10) for supplying the set of vehicle wheels (20, 22), wherein the drive module (10) is operable in a torque-vectoring mode and in at least one propulsion mode; Switching the drive module (10) to the torque vectoring mode when a first set of conditions is met; Switching the drive module (10) to one of the propulsion modes when a second set of conditions is met; Switching the drive module (10) to one of the propulsion modes when a third set of conditions is met; where the first sentence has conditions: a torque requested by an operator of the vehicle (12) is less than or equal to a first predetermined request threshold; and a speed of the vehicle (12) is greater than or equal to a first predetermined speed threshold; the second sentence contains conditions: the speed of the vehicle (12) is less than a second predetermined speed threshold; and a lateral instability of the vehicle (12) is less than or equal to a first predetermined instability threshold; and the third set of conditions includes: The torque requested by the operator of the vehicle (12) is greater than a second predetermined request threshold. [2] Method according to claim 1, wherein the first set of conditions further comprises: a torque output (10) of the drive module is less than or equal to a predetermined torque threshold. [3] Method according to claim 1, wherein the second sentence further comprises conditions: an energy level of a power storage device (34) is greater than or equal to a predetermined energy level. [4] Method according to claim 1, wherein the second predetermined requirement threshold is greater than or equal to the first predetermined requirement threshold. [5] Method according to claim 1, wherein the second predetermined speed threshold is less than or equal to the first predetermined speed threshold. [6] Method according to claim 1, wherein the at least one propulsion mode comprises a first propulsion mode and a second propulsion mode, and wherein the method comprises switching the drive module (10) to the first propulsion mode when the second set of conditions is met, and switching the drive module (10) to the second propulsion mode when the third set of conditions is met. [7] Method according to claim 6, wherein the first propulsion mode is a low-speed propulsion mode and the second propulsion mode is a high-speed propulsion mode. [8] Control unit (210) for a drive module (10) in a vehicle (12) that can be operated in a variety of modes to drive a pair of vehicle wheels (20, 22), wherein the control unit (210) is configured to: to determine a torque requested by an operator of the vehicle (12), a speed of the vehicle (12) and a level of instability of the vehicle (12); to switch the drive module (10) to a torque-vectoring mode when a first set of conditions is met; and to switch the drive module (10) to a propulsion mode when either a second set of conditions is met or a third set of conditions is met; where the first sentence has conditions: the torque requested by the vehicle operator is less than or equal to a first predetermined request threshold; and the speed of the vehicle (12) is greater than or equal to a first predetermined speed threshold; the second sentence contains conditions: the speed of the vehicle (12) is less than a second predetermined speed threshold; and a lateral instability of the vehicle (12) is less than or equal to a first predetermined instability threshold: and the third set of conditions includes: The torque requested by the operator of the vehicle (12) is greater than a second predetermined request threshold. [9] Control unit (210) according to claim 8, wherein the first set of conditions further comprises: a torque output of the drive module (10) is less than or equal to a predetermined torque threshold value. [10] Control unit (210) according to claim 8, wherein the second set of conditions further includes: an energy level of a power storage device (34) is greater than or equal to a predetermined energy level. [11] Control unit (210) according to claim 8, wherein the second predetermined request threshold is greater than or equal to the first predetermined request threshold. [12] Control unit (210) according to claim 8, wherein the second predetermined speed threshold is less than or equal to the first predetermined speed threshold. [13] Control unit (210) according to claim 8, wherein the control unit (210) is configured to switch the drive module (10) to a low-speed propulsion mode when the second set of conditions is met, and to switch the drive module (10) to a high-speed propulsion mode when the third set of conditions is met. [14] Drive module (10) for propelling a vehicle (12), the drive module (10), comprising: a motor (32); an input element (86) which is driven by the motor (32); a differential assembly (36) with a differential carrier (83) and a first and second differential output (100, 102) which are accommodated in the differential carrier (83); a gearbox (30) that receives rotational force from the input element (86); a switchable element (152) that is axially movable between a first position and a second position, wherein the positioning of the switchable element (152) in the first position couples the transmission (30) to the differential assembly (36) to establish a torque-vectoring mode in which the transmission (30) applies an equal but oppositely directed torque to the first and second differential outputs (100, 102), and wherein a positioning of the switchable element (152) in the second position couples the transmission (30) to the differential assembly (36) to directly drive the differential carrier (83); an actuator (150) coupled to the switchable element (152) and configured to move the switchable element (152) axially between the first and second positions; and a control module (210) configured to control the actuator (150) to move the switchable element (152) to the first position when a first set of conditions is met, and to move the switchable element (152) to the second position when one of the conditions of a second set of conditions is met or a third set of conditions is met; where the first sentence has conditions: a torque requested by the operator of the vehicle (12) is less than or equal to a first predetermined request threshold: and a speed of the vehicle (12) is greater than or equal to a first predetermined speed threshold; the second sentence contains conditions: the speed of the vehicle (12) is less than a second predetermined speed threshold; and a lateral instability of the vehicle (12) is less than or equal to a first predetermined instability threshold; and the third set of conditions includes: The torque requested by the operator of the vehicle (12) is greater than a second predetermined request threshold. [15] Drive module (10) according to claim 14, wherein the first set of conditions further comprises: a torque output of the drive module (10) is less than or equal to a predetermined torque threshold value. [16] Drive module (10) according to claim 14, wherein the second set of conditions further includes: an energy level of a power storage device (34) is greater than or equal to a predetermined energy level. [17] Drive module (10) according to claim 14, wherein the second predetermined request threshold is greater than or equal to the first predetermined request threshold. [18] Drive module (10) according to claim 14, wherein the second predetermined speed threshold is less than or equal to the first predetermined speed threshold. [19] Drive module (10) according to claim 14, wherein the transmission (30) has a first planetary stage (40) and a second planetary stage (42), wherein the first planetary stage (40) has a first sun gear (50) coupled to a second sun gear (70) of the second planetary stage (42) for common rotation. [20] Drive module (10) according to claim 19, wherein the switchable element (152) is axially movable to a third position, wherein the positioning of the switchable element (152) in the third position couples the transmission (30) to the first and second sun gear (50, 70) to directly drive the first and second sun gear (50, 70), wherein the control module (210) is configured to control the actuator (150) to move the switchable element (152) to the third position when the second set of conditions is met, and to move the switchable element (152) to the second position when the third set of conditions is met.

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