Locking differential assembly

Abstract

The utility model relates to a differential locking assembly. In one example, a locking differential assembly includes an input gear configured to be rotationally coupled to an upstream component; a housing coupled to the input gear; and a lock clutch configured to lock rotation of the housing and the side gear in an engaged configuration. The lock differential assembly also includes an actuation system configured to engage and disengage the lock clutch according to the steering angle.

Description

Technical Field

[0001] The present disclosure relates to a locking differential assembly with a locking clutch. Background Art

[0002] Some drivetrain systems utilize limited slip differentials to improve vehicle traction compared to open differentials. Limited slip differentials allow the output shafts to have different angular velocities, but impose limits on the angular velocity changes. Clutch packs on the side gears of the limited slip differential accomplish this. Other fully locking differentials are used on some vehicles to further improve traction by locking the side gears together.

[0003] US Patent No. 8,051,744 B2 issued to Bawks et al. discloses a locking differential system for powering an output shaft. The locking differential system includes springs that automatically engage and disengage the torsional joint based on the speed difference between the side gears.

[0004] The inventors have recognized that there are some disadvantages with Bucks' locking differential and other previous differential systems. For example, certain components in Bucks' locking differential require complex manufacturing techniques. For example, the shape of the components and the spring characteristics that engage and disengage the locking function may be difficult to achieve in the manufacturing process. In addition, the inventors have recognized that it may be desirable to unlock the differential at relatively high vehicle speeds to reduce the chance of degradation of certain components in the differential. Utility Model Content

[0005] In the face of the above problems, the inventors have developed a locking differential assembly to overcome at least some of the problems. In one example, the locking differential assembly includes an input gear and a housing, the input gear is rotationally coupled to the upstream component, and the housing is coupled to the input gear. The locking differential assembly also includes a locking clutch, which is configured to lock the rotation of the housing and the side gears in an engaged state. The locking differential assembly even further includes an actuation system, which is configured to engage and disengage the locking clutch according to the steering angle. In this way, when the vehicle is traveling on a curve, the steering angle of the vehicle can trigger the locking and unlocking of the differential, so that the differential can function as an open differential; when the vehicle is traveling on a relatively straight line, the differential can lock the relative axle shafts so that they rotate at the same speed, thereby increasing traction. In addition, the above functions can also be implemented in a reliable, space-saving, and manufacturing-efficient assembly. In addition, the assembly allows the locking differential to implement the additional functions of the locking differential, which increases production flexibility by increasing the complexity of the differential control scheme rather than the structure of the differential (if necessary).

[0006] Additionally, in one example, the actuation system may include a hydraulic valve in hydraulic communication with a hydraulic actuator of the locking clutch. The hydraulic valve may be actively adjusted by a controller in one example, or mechanically adjusted by a steering mechanism in another example. In this way, the locking clutch can be reliably activated using the vehicle steering angle as a disengagement condition. Additionally, when the hydraulic valve is adjusted using controller commands, an active locking and unlocking strategy may be employed. For example, the locking clutch may be actively disengaged when the vehicle speed exceeds a threshold speed. As a result, the probability of component degradation in the differential is reduced, thereby extending the service life of the differential.

[0007] It should be understood that the above summary is intended to introduce in a simplified form the concepts that are further described in the detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely determined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of a vehicle including a power assembly with a locking differential assembly is shown.

[0009] Figure 2 An example of a locking differential assembly is shown in a disengaged configuration.

[0010] Figure 3 Shows Figure 2 A locking differential assembly is shown in a transient state between a disengaged configuration and an engaged configuration.

[0011] Figure 4 Shows Figure 2 The locking differential assembly described in FIG. 1 is engaged.

[0012] Figure 5 The operation of the differential assembly is shown.

[0013] Figure 6 The steering mechanism of the axle assembly is shown. DETAILED DESCRIPTION

[0014] A reliable and space-saving locking differential assembly with active locking is provided herein. The locking differential includes a locking clutch that can be actively adjusted using an actuation system based on the steering angle of the vehicle. The actuation system can include a hydraulic valve for triggering the adjustment of a locking clutch hydraulic actuator. A controller or a steering mechanism can be used to control the adjustment of the hydraulic valve to achieve engagement and disengagement of the locking clutch.

[0015] Figure 1A schematic diagram of a vehicle 100 is shown. In different examples, the vehicle can be a passenger vehicle, a commercial vehicle, an on-road vehicle, or an off-road vehicle. In the off-road vehicle example, the size and / or maximum speed of the vehicle may prevent it from being driven on a highway. For example, the width of the vehicle may be greater than a highway lane, and / or the maximum speed may be less than the minimum highway speed. However, in other examples, the vehicle may be an on-road vehicle such as a commercial vehicle or a passenger vehicle.

[0016] In the vehicle example, vehicle 100 includes a power assembly 102 with a transmission 104 (e.g., a gearbox) and a prime mover 106 (e.g., an internal combustion engine and / or an electric motor). When the prime mover is an electric motor, the electric motor may be included in the electric drive system. Prime mover 106 provides mechanical power to the transmission during operation of the power assembly. In the case of an electric drive, when the electric motor operates as a generator, power may flow from the transmission to the electric motor.

[0017] Additionally, the transmission 104 is mechanically coupled to a transaxle assembly 110 . The transaxle assembly 110 may include a locking differential assembly 112 , axle shafts 122 and 124 , and / or drive wheels 126 and 128 .

[0018] The transmission 104 may include gears, shafts, etc., which function to change the speed of the prime mover mechanical input to achieve a speed change at the transmission output. The transmission may be a multi-speed transmission, a continuously variable transmission, a single-speed transmission, etc.

[0019] The locking differential assembly 112 includes a locking clutch 118, which may include an actuator 120 (e.g., a hydraulic actuator). The actuator 120 is configured to engage and disengage the locking clutch 118 to lock and unlock the differential. When locked, shafts 122 and 124 of the differential rotate at the same speed. The shafts 122 and 124 are rotationally connected to drive wheels 126 and 128. Conversely, when the differential is unlocked, a speed difference between the shafts 122 and 124 is allowed. Therefore, the locking differential can be used as an open differential when unlocked.

[0020] The actuator 120 can be adjusted by the actuation system 130. In one example, the working fluid in the actuation system can be oil. The actuation system 130 can include a hydraulic valve 132 that is hydraulically coupled to the actuator 120 via a fluid line 134. The actuation system 130 can include a fluid source 136 (e.g., a pump). In one example, the hydraulic valve 132 can be actively electronically controlled by a command of a controller 191, which will be discussed in detail herein. In detail, a steering signal from the controller can be used to drive the hydraulic valve 132. For example, a steering signal indicating that the steering angle is greater than a threshold can close the hydraulic valve, and a steering signal indicating that the steering angle is less than the threshold can open the hydraulic valve. The actuation system 130 can automatically lock and unlock the locking clutch 118 without the operator interacting with the input device to trigger the adjustment of the differential locking clutch position. However, in some examples, the operator can also lock and unlock the locking clutch via an input device, which can override the automatic locking and locking control strategy, and vice versa.

[0021] In addition, the hydraulic valve 132 can also be mechanically actuated by a mechanical device 138 (such as a shaft, cam, rod, combination thereof, etc.), which is connected to or integrated in the steering mechanism 140. For example, in this case, the valve can be activated by a lever integrated in the valve: when the vehicle starts to turn, one of the steering mechanism components moves the lever, and once the steering angle is zero, the lever returns to the neutral position. In this way, the valve configuration is mechanically connected to the steering mechanism configuration, and the valve is closed when the vehicle is not turning, and the valve is open when the vehicle is turning.

[0022] Figure 6 An example of a steering mechanism 600 is shown. The steering mechanism 600 may include a hydraulic piston 602 that may selectively receive hydraulic fluid from a fluid line 604 or other suitable component. The hydraulic piston 602 changes the position of a rod 606 that adjusts a steering knuckle 608 via a tie rod 607. In detail, the tie rod may be pushed or pulled to rotate the steering knuckle.

[0023] Continue watching Figure 1 , the steering mechanism 140 may be configured to change the steering angle of the wheel 142 in the axle assembly 144. The steering mechanism 140 may include an input device (e.g., a steering wheel), a pinion, a steering column, and other components for changing the steering angle of the wheel 142. In other examples, the steering mechanism 140 may be configured to change the steering angle of the wheels 124, 126.

[0024] Figure 1 The locking differential assembly 112 is schematically illustrated in FIG. However, it will be appreciated that the differential and locking device have greater structural and functional complexity, which will be discussed in detail below. Figure 2-4The exemplary clutch assembly described in is further described in detail.

[0025] like Figure 1 As shown, the prime mover 106, the transmission 104 and the drive axle assembly 110 are spaced apart from each other. However, it is understood that one or more of these components can be combined with each other in one assembly. For example, when the vehicle is an electric vehicle, in other examples, the motor, the transmission and the axle assembly can form an electric axle.

[0026] like Figure 1 As shown, the vehicle 100 may further include a control system 190 with a controller 191 (such as a powertrain control unit (DCU)). The controller 191 may include a microcomputer whose components include a processor 192 (such as a microprocessor unit), input / output ports, and an electronic storage medium 194 for executable programs and calibration values ​​(such as a read-only memory chip, random access memory, keep-alive memory, data bus, etc.). The storage medium can be programmed with computer-readable data that represents instructions executable by the processor for performing the methods and control techniques described herein, as well as other variants that are expected but not specifically listed. Therefore, the control techniques, methods, etc. described herein can be stored as instructions in a non-transitory memory.

[0027] The controller 191 may receive various signals from sensors 195 that are connected to various areas of the vehicle 100. For example, the sensors 195 may include pedal position sensors for detecting depression of operator actuation pedals such as an accelerator pedal and / or a brake pedal, speed sensors on the transmission input and / or output shafts, gear selector sensors, clutch position sensors, etc. Input devices 198 (e.g., an accelerator pedal, a brake pedal, a drive mode selector, a gear selector, combinations thereof, etc.) may further provide input signals indicative of the operator's vehicle control intent.

[0028] Upon receiving Figure 1 After receiving signals from various sensors 195, the controller 191 processes the received signals and uses various actuators 196 of system components to adjust the components based on the received signals and instructions stored in the memory of the controller 191. For example, the controller 191 can be designed to engage and disengage locking devices. For example, the controller 191 can determine that the differential should be locked and send a locking control instruction to the valve 132. For example, other controllable components in the system can function in a similar manner in terms of sensor signals, control instructions, and actuator adjustments.

[0029] Figure 1 as well as Figure 2-4 and Figure 6An axis system is provided for reference. In one example, the z-axis can be a vertical axis (e.g., parallel to the gravity axis), the x-axis can be a lateral axis (e.g., a horizontal axis), and / or the y-axis can be a longitudinal axis. However, in other examples, these axes may have other orientations.

[0030] Figure 2-4 An example of a locking differential assembly 200 is shown. The locking differential assembly 200 is Figure 1 One example of a locking differential assembly 112 is shown.

[0031] See Figure 2 , an unlocked configuration of a locking differential assembly 200 is shown in the figure, wherein the locking clutch 202 is in a disengaged state. The locking differential assembly 200 includes an input gear 204 (e.g., a ring gear) having a profile connected to an upstream component 205, such as a pinion connected to a drive shaft that is connected to a transmission. As described herein, the inputs and outputs discussed in connection with the locking differential assembly correspond to a differential operating mode when mechanical power is transmitted from an upstream driveline component through the differential to the drive wheels. However, it will be appreciated that under certain conditions and powertrain configurations, power may flow in the opposite direction. For example, in the case of an electric powertrain, mechanical power may be transmitted from the drive wheels through the differential to the upstream component during regenerative operation.

[0032] The input gear 204 may be connected to the housing 206. For example, the input gear 204 may be fixedly connected to the housing 206 using a connection device 207 so that the input gear 204 rotates synchronously. However, other suitable connection techniques may be used to connect the input gear 204 to the housing 206, such as welding, interference fit, or a combination thereof. In addition, the input gear 204 may also be formed in the housing 206 by machining or the like.

[0033] A bearing 208 (e.g., a tapered roller bearing) may be connected to the housing 206 and the housing 210. The bearing 208 allows the housing 206 to rotate within the housing 210. The bearings described herein may include raceways (e.g., inner raceways and outer raceways) and roller elements (e.g., balls, cylindrical rollers, tapered cylindrical rollers, etc.). The bearing housing 210 may include a base plate 211 for collecting oil or other suitable lubricants.

[0034] The locking differential assembly 200 may further include a shaft 212 (eg, a pinion shaft) connected to the housing 206 via an opening 214 and / or other suitable techniques. Therefore, when the drive axle is operating and providing power to the drive wheels, the housing 206 drives the housing to rotate.

[0035] The locking differential assembly 200 may also include a pinion gear 216, which may be referred to as a spider gear. The pinion gear 216 meshes with side gears 218, 220. The side gears 218, 220 include a mechanical interface 222 (e.g., a spline) that allows a shaft 224, 226 (e.g., an output shaft) to be rotationally connected. As shown by arrow 231, the shaft 224, 226 is rotationally connected to the drive wheels 227, 229.

[0036] When the locking clutch 202 is disengaged, as shown in FIG. Figure 2 As shown, the speed of the side gears 218, 220 can be varied, and therefore the speed of the shafts 224, 226 can also be varied. Thus, when the locking clutch is disengaged and the differential is in the unlocked state, the differential functions as an open differential. When the vehicle is turning, it is best to place the differential in the unlocked state. Conversely, when the vehicle is traveling substantially straight, it is best to place the differential in the locked state to increase axle traction. The operation of a locking differential will be described in detail in Figure 5 Detailed description in.

[0037] like Figure 2 As shown, the locking clutch 202 may include a hydraulic actuator 228. The hydraulic actuator 228 may include a spring 230, a hydraulic chamber 232 (e.g., a piston chamber), and the hydraulic chamber may adjust the position of a piston 234. In the illustrated example, the spring 230 is connected to the piston 234 and the housing 206. However, other clutch configurations may also be used in other embodiments. The hydraulic chamber 232 may be at least partially defined by an outer wall 233, one of the bearings 208.

[0038] In one example, the piston 234 can be splined to the housing 206 so that the piston can move along the axis 236. A retaining ring 235 can be used to limit the axial movement of the piston 234.

[0039] During actuation, the piston 234 moves along the axis 236. The movement of the piston 234 allows the locking assembly 238 (e.g., a locking ball) to move radially inward and outward (relative to the rotation axis 264 of the housing 206) to lock the housing so that it rotates with the side gear 220. Figure 4 As shown, when the locking clutch is engaged, the spherical locking member 238 can cooperate with the groove 240 in the side gear 220. In detail, the ramp in the piston can be driven to push the locking member 238 radially inward into the groove 240 in the side gear. The locking clutch 202 also includes a spring 221. Therefore, engaging the locking clutch 202 can lock the side gear to rotate synchronously with the axle shaft, thereby increasing axle traction.

[0040] The actuation system 242 can be used to change the configuration of the hydraulic actuator 228. For example, the actuation system 242 can include a hydraulic valve 244. In a specific example, the hydraulic valve can be a two-position solenoid valve. However, other valve designs can also be used in other examples. Figure 2 24, in which the hydraulic valve inhibits the flow of fluid from the fluid source 246 to the hydraulic actuator 228. Therefore, the fluid pressure in the hydraulic chamber 232 is below the threshold pressure. For example, in one use case, when the hydraulic valve 244 is closed, the fluid pressure in the hydraulic chamber 232 may be approximately 0 bar. Conversely, the hydraulic valve 244 may be placed in an open configuration, at which time the pressure in the hydraulic chamber 232 is higher, which may induce the locking clutch to engage (e.g., 15-30 bar in one use example).

[0041] The hydraulic valve 244 can be electronically and / or mechanically adjusted between an open and closed position. For example, a controller (such as Figure 1 The controller 191 shown in FIG. 1 may command adjustment of the hydraulic valve 244 and / or the steering mechanism may be mechanically connected to the hydraulic valve 244 for adjustment.

[0042] The fluid source 246 can provide fluid to the hydraulic valve within a certain pressure range. For example, in one use case, the pressure range provided to the hydraulic valve 244 is 15-30 bar. The hydraulic valve 244 can also include a spring 248. The hydraulic valve 244 is hydraulically coupled to the hydraulic chamber 232 via a hydraulic conduit 245.

[0043] The constant of spring 230 may determine the pressure of the fluid in chamber 232 to move piston 234 in direction 250. In a specific example of use, a chamber pressure in the range of 15-30 bar may cause piston 234 to move in direction 250. Figure 2 The rotation axes 260 and 262 of the side gears 218 and 220, respectively, and the rotation axis 264 of the housing 206 and other differential components are provided for reference.

[0044] Figure 3 The locking clutch 202 of the locking differential assembly 200 is shown in a transient configuration, wherein the pressure in the hydraulic chamber 232 has increased, but the locking clutch is still in a disengaged state. To increase the pressure in the hydraulic chamber 232, the valve 244 is switched to an open position, allowing fluid to flow through the hydraulic valve into the hydraulic chamber 232. Figure 3 In the clutch configuration shown, spring 230 is in a minimally compressed state (e.g., substantially uncompressed). A transient configuration will occur when the speed differential between axles 224 and 226 is greater than a threshold. When the axial speed differential drops below the threshold, locking clutch 202 engages and piston 234 moves in direction 250, pushing locking member 238 radially inward to engage recess 240.

[0045] Figure 4 The locking clutch 202 of the locking differential assembly 200 is shown in an engaged state. As described above, to place the locking clutch 202 in the engaged configuration, the hydraulic valve 244 is moved from the closed configuration to the open configuration to increase the pressure in the hydraulic chamber 232. The increase in pressure in the chamber pushes the piston 234 to move the locking member 238 radially inwardly, causing it to mate with the groove 240 and lock the housing 206 to rotate with the side gear 220. Figure 4 As shown, when the piston 234 moves in the direction 250, the spring 230 will be compressed and may reach a maximum compression. However, other clutch configurations are also contemplated. In this way, the differential is locked, allowing the axles 224 and 226 to rotate at the same speed. Therefore, the traction performance of the vehicle is improved. Conversely, to return the locking clutch 202 to the disengaged position, the pressure in the hydraulic chamber 232 can be reduced, causing the spring 230 to decompress and move the piston 234, thereby disengaging the locking member 238 from the groove 240.

[0046] Figure 5 A method 500 of operating a locking differential assembly is shown. In one example, the method 500 may be performed as described herein with respect to Figure 1-4 The method 500 may be performed by any locking differential assembly and related mechanisms, systems, etc. described herein or a combination of locking differential assemblies and related systems. In other examples, the method 500 may be implemented by other suitable locking differential assemblies. In addition, as previously described, the method 500 may be implemented by a controller including a memory for storing method step instructions executable by a processor. However, in some examples, some method steps may be passively performed, such as when a hydraulically actuated valve for locking the clutch is mechanically coupled to a steering mechanism.

[0047] Figure 5 The illustrated method 500 includes determining operating conditions at 502. The operating conditions may include locking clutch position, vehicle speed, vehicle steering angle, accelerator pedal position, transmission input / output speed, vehicle load, ambient temperature, combinations thereof, etc. The operating conditions may be determined by sensor input, modeling, lookup tables, and / or other suitable techniques. For example, vehicle speed may be measured by a speed sensor on a drive wheel, and steering angle may be measured by a sensor in a steering system.

[0048] At 504, the method includes determining whether the steering angle is greater than a threshold value (e.g., a non-zero value). Therefore, a comparison can be made between the vehicle steering angle determined in step 502 and a predetermined threshold angle. If it is determined that the steering angle is greater than the threshold angle (YES at 504), the method proceeds to 506, where the method includes disengaging the locking clutch. As previously described, the locking clutch can be actively disengaged via a control command, which is sent to a hydraulic valve, thereby triggering adjustment of the locking clutch hydraulic actuator. In detail, the hydraulic valve can be closed to reduce the fluid pressure in the clutch hydraulic chamber, thereby moving the clutch piston to a disengaged position or maintaining it in a disengaged position. In addition, a steering mechanism can also be used to mechanically drive the hydraulic valve.

[0049] On the contrary, if it is determined that the steering angle is not greater than the threshold angle (NO at 504), the method proceeds to 506. It is understood that step 506 may be selectively included in method 500. If step 506 is omitted from the method, if it is determined that the steering angle is not greater than the threshold angle (NO at 504), the method proceeds to 508.

[0050] At 507 , the method includes determining whether the vehicle speed is greater than a threshold speed (eg, a non-zero value). Thus, a comparison may be made between the vehicle speed determined at step 502 and a predetermined threshold speed.

[0051] If it is determined that the vehicle speed is greater than the threshold speed (“Yes” at 507 ), the method proceeds to 506 . On the other hand, if it is determined that the vehicle speed is not greater than the threshold speed (NO at 507 ), the method proceeds to 508 .

[0052] At 508, the method includes engaging the locking clutch or maintaining engagement of the locking clutch. For example, the pressure of the hydraulic fluid delivered to the clutch actuator through the hydraulic valve can be increased or maintained at a relatively high pressure (e.g., 15-30 bar in one use case). The method 500 allows the differential lock to be engaged and disengaged in certain situations using the vehicle steering angle and vehicle speed, thereby improving the traction performance of the vehicle.

[0053] The technical effect of the differential assembly locking operation method described herein is to effectively lock and unlock the differential according to the steering angle and / or vehicle speed, thereby improving traction performance with an efficient and reliable spatial combination.

[0054] Figure 2-4 and Figure 6 Except for the components depicted schematically, they are generally drawn to scale. However, other relative component sizes may be used in other examples.

[0055] Figure 1-4 and Figure 6Configuration examples of relative positioning of various components are shown. If the elements shown in the figure are in direct contact or directly coupled to each other, then at least in one example, these elements can be referred to as direct contact or direct coupling, respectively. Similarly, at least in one example, the elements shown as adjacent or adjacent to each other can be adjacent or adjacent to each other, respectively. For example, elements that are in face-to-face contact with each other can be referred to as face-to-face contact elements. Another example is that, at least in one example, the elements are placed separately from each other, with only space in the middle and no other elements, which can be referred to as being placed separately from each other. For example, relative to each other, the elements displayed above / below each other, relative to both sides of each other, or relative to the left / right side of each other can be referred to as such elements. In addition, as shown in the figure, in at least one example, the topmost element or element point can be referred to as the "top" of the element, and the bottommost element or element point can be referred to as the "bottom" of the element. As used herein, up / down, up / down, up / down can be relative to the vertical axis in the figure to describe the positioning of each element in the figure relative to each other. Therefore, in one example, the element displayed above other elements is vertically positioned above other elements. For another example, the shapes of the elements depicted in the figure may be referred to as having these shapes (such as circular, linear, planar, curved, rounded, chamfered, beveled, or similar shapes). In addition, in one example, elements that are coaxial with each other may be referred to as coaxial elements. In addition, at least in one example, elements that are shown to intersect with each other may be referred to as intersecting elements or intersecting with each other. In addition, in one example, elements that are displayed within another element or displayed outside another element may be referred to as intersecting elements. In other examples, elements that are offset from each other may also be referred to as such. Even further, elements that are coaxial or parallel to each other may also be referred to as such elements. Further, the axis around which the element rotates may be referred to as a rotation axis. Elements that are fixedly coupled to each other may be referred to as rotation axes.

[0056] The utility model will be further described below. In one aspect, the utility model provides a locking differential assembly, the assembly comprising an input gear configured to be rotationally coupled to an upstream assembly; a housing coupled to the input gear; a locking clutch configured to lock the rotation of the housing and the first side gear in a meshing configuration; and

[0057] An actuation system that engages and disengages the lockup clutch based on steering angle.

[0058] In another aspect, a method for operating a locking differential assembly is provided, the method comprising disengaging a locking clutch in the locking differential assembly in response to a steering angle exceeding a threshold angle; wherein the locking differential assembly comprises: an input gear configured to be rotationally coupled to an upstream component; a housing coupled to the input gear; and a locking clutch configured to lock rotation of the housing and a first side gear in an engaged configuration. In one example, the method may further comprise disengaging the locking clutch when a vehicle speed exceeds a threshold speed. Further, in one example, the method may further comprise engaging the locking clutch in response to a steering angle decreasing below a threshold angle.

[0059] In another aspect, a locking differential assembly is provided, the assembly comprising an input gear configured to be rotationally coupled to an upstream component; a housing coupled to the input gear; a locking clutch configured to lock rotation of the housing and a first side gear in an engaged configuration; an actuation system comprising a hydraulic valve hydraulically coupled to a hydraulic actuator of the locking clutch; wherein the hydraulic actuator is configured to engage and disengage the locking clutch; wherein the actuation system is configured to selectively disengage the locking clutch based on a steering angle and / or a vehicle speed.

[0060] In any aspect or combination of the above, the actuation system may include a controller configured to send a command to a hydraulic valve in hydraulic communication with a hydraulic actuator of the locking clutch.

[0061] In any or any combination of the above aspects, the controller may include instructions that, when executed, may cause the controller to: disengage the locking clutch when the steering angle exceeds a threshold angle.

[0062] In any aspect or combination of the above, the controller may include instructions that, when executed, cause the controller to: disengage the locking clutch when a vehicle speed exceeds a threshold speed.

[0063] In any aspect or combination of the above, the actuation system may include a mechanical device configured to change a configuration of a hydraulic valve in hydraulic communication with a hydraulic actuator of the locking clutch.

[0064] In any or any combination of the above aspects, the mechanical device may be connected to the steering mechanism.

[0065] In any or any combination of the above aspects, the locking clutch may include a plurality of balls having a profile that matches the grooves in the first side gear.

[0066] In any or any combination of the above aspects, the assembly may further include a plurality of pinion gears meshing with a first side gear and a second side gear, wherein the first side gear is rotationally connected to the first shaft and the second side gear is rotationally connected to the second shaft.

[0067] In any or any combination of the above aspects, a locking differential assembly may be included in an off-highway vehicle.

[0068] In any aspect or combination of the above aspects, the locking differential assembly may further include an actuation system configured to engage and disengage the locking clutch based on steering angle.

[0069] In any aspect or combination of the above aspects, the actuation system may be a controller configured to change a position of a hydraulic valve in fluid communication with a hydraulic actuator coupled to the locking clutch.

[0070] In any or any combination of the above aspects, the hydraulic actuator may engage the locking clutch when a pressure in the hydraulic actuator chamber is greater than a threshold pressure.

[0071] In any or any combination of the above aspects, the actuation system may include a controller including instructions, execution of which may cause the controller to: disengage the locking clutch in response to the steering angle exceeding a threshold angle.

[0072] In any or any combination of the above aspects, the controller may include instructions that, when executed, cause the controller to: disengage the locking clutch in response to the vehicle speed exceeding a threshold speed.

[0073] In any or any combination of the above aspects, the controller may include instructions that, when executed, cause the controller to: engage the locking clutch in response to: a steering angle decreasing below a threshold angle; and a vehicle speed decreasing below a threshold speed.

[0074] In another representation, a locking differential in a transmission system is provided, which includes a locking device with a hydraulic piston that selectively locks the rotation of the housing and side gears based on steering angle and / or vehicle speed via a plurality of balls and detents in the housing.

[0075] Please note that the control and estimation routine examples included herein can be used in various system (e.g., transmission) configurations. The control methods and routines disclosed herein can be stored as executable instructions in a non-temporary memory and can be executed by a control system including a controller combined with an electronic controller and various sensors, actuators, and other system hardware. Therefore, the actions, operations, and / or functions described can graphically represent the code that will be programmed into the non-temporary memory of a computer-readable storage medium in a vehicle and / or powertrain control system. The various operations, operations, and / or functions illustrated can be performed in the order illustrated, in parallel, or omitted in some cases. Similarly, the processing order is not necessarily required to achieve the features and advantages of the examples described herein, but is only for ease of illustration and description. Depending on the specific strategy used, one or more of the actions, operations, and / or functions illustrated can be repeated. If necessary, one or more of the method steps described herein can be omitted.

[0076] Although various embodiments are described above, it should be understood that these embodiments are examples only and not limitations. It is obvious to those familiar with the relevant technology that the disclosed subject matter can be embodied in other specific forms without departing from the spirit of the subject matter. Therefore, the embodiments described above should be considered illustrative and not restrictive in all respects. Therefore, the configurations and routines disclosed herein are exemplary in nature, and these specific examples should not be considered restrictive because there can be many variations. For example, the above-mentioned technology can be applied to power systems containing different types of propulsion sources, including different types of traction motors, internal combustion engines and / or transmissions. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of various systems and configurations, as well as other features, functions and / or characteristics disclosed herein.

[0077] The following claims particularly point out certain combinations and subcombinations regarded as novel and non-obvious. The claims may refer to "an" element or a "first" element or the equivalent. The claims should be understood to include one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amendment of the present claims or by presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, are also deemed to be included in the subject matter of the present disclosure.

Claims

1. A locking differential assembly, characterized in that: include: an input gear for rotationally coupling with an upstream component; a housing connected to the input gear; a locking clutch configured to lock rotation of the housing and the first side gear in an engaged state; as well as An actuation system is provided for engaging and disengaging the lock-up clutch based on steering angle.

2. The locking differential assembly of claim 1 , wherein the actuation system comprises a controller configured to: A command is sent to a hydraulic valve that is in hydraulic communication with a hydraulic actuator of the lockup clutch.

3. The locking differential assembly of claim 2, wherein the controller includes instructions that, when executed, cause the controller to: When the steering angle exceeds a threshold angle, the locking clutch is disengaged.

4. The locking differential assembly of claim 2, wherein the controller includes instructions that, when executed, cause the controller to: When the vehicle speed exceeds a threshold speed, the lock-up clutch is disengaged.

5. The locking differential assembly of claim 1 wherein the actuation system includes a mechanical device that changes a configuration of a hydraulic valve in hydraulic communication with a hydraulic actuator of the locking clutch.

6. The locking differential assembly of claim 5 wherein the mechanical device is coupled to a steering mechanism.

7. The locking differential assembly of claim 1 wherein said locking clutch includes a plurality of balls having a profile that matches a groove of said first side gear.

8. The locking differential assembly of claim 1, wherein: Also included are a plurality of pinion gears meshing with a first side gear and a second side gear, wherein the first side gear is rotationally connected to the first shaft and the second side gear is rotationally connected to the second shaft.

9. The locking differential assembly of claim 1, wherein the locking differential assembly is included in an off-highway vehicle.

10. The locking differential assembly of claim 1 wherein the actuation system includes a controller including instructions that, when executed, cause the controller to: disengaging the lockup clutch when the steering angle exceeds a threshold angle; disengaging the lock-up clutch when the vehicle speed exceeds a threshold speed; and engages the lockup clutch in response to The steering angle decreases below a threshold angle; and The vehicle speed is below the threshold speed.

11. The locking differential assembly of claim 1, wherein: Also included is a hydraulic actuator configured to engage the lock-up clutch when a pressure within the hydraulic actuator chamber is greater than a threshold pressure.

12. The locking differential assembly of claim 1 , wherein the controller includes instructions that, when executed, cause the controller to: engages the lockup clutch in response to The steering angle decreases below a threshold angle; and The vehicle speed is below the threshold speed.

13. The locking differential assembly of claim 1 wherein said locking clutch includes a plurality of balls having a profile that matches a groove of said first side gear.

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