Transmission system for vehicle

Abstract

The utility model relates to a transmission system for a vehicle. In one example, a drivetrain includes an axle shaft with a radial projection and a shaft guide surrounding the axle shaft. The shaft guide may have an inner radial groove configured to be in interference fit with the radial projection. The axle shaft may be disconnected from the hub of the vehicle when the axle shaft translates axially with the radial projection engaged with the inner radial groove of the axle shaft guide.

Description

Technical Field

[0001] This description generally relates to methods and systems for vehicle axle assemblies. Background Art

[0002] An electric vehicle may include a drivetrain that connects an electric motor and a gear system to a wheel. In some cases, it may be necessary to disconnect the axle shaft from the drivetrain so that the wheel can rotate independently of the electric motor and the gear system. For example, when towing a vehicle on flat ground or in neutral, all of the vehicle's wheels remain in contact with the ground. When the vehicle is towed, the wheels rotate accordingly, and if engaged with the transmission of the vehicle's powertrain through the axle shaft, the main axle shaft of the transmission can be driven to rotate.

[0003] In the case of a hybrid or electric vehicle, the rotation of the transmission can be transmitted to at least one electric motor connected to the transmission. This can cause the vehicle's energy storage device to be overcharged, thereby reducing the performance of the energy storage device and other electrical components of the vehicle. In addition, the friction generated when the electric motor rotates during flat towing can cause the electric motor to overheat. Further, in the case where the vehicle relies on an electric oil pump to lubricate the powertrain components, the electric oil pump may be deactivated in the towing mode. Without the lubricating oil circulating, the powertrain components may degrade when forced to rotate.

[0004] During flat towing, attempts to address the undesirable rotation of the transmission and the electric motor include strategies for decoupling the wheels from the vehicle's powertrain. For example, one or more axle shafts of the vehicle can be disconnected from the transmission. Disconnecting the axle shaft may require completely removing the axle shaft from the vehicle because once disconnected, the position of the axle shaft cannot be maintained as it may no longer be mechanically supported. However, removing and storing the axle shaft can be both cumbersome and inconvenient. Summary of the Utility Model

[0005] In one example, the above problem can be solved by a drivetrain for a vehicle, the drivetrain having an axle shaft with a radial protrusion protruding from an outer surface of the axle shaft, and an axle guide surrounding the axle shaft, the axle guide having an inner radial groove configured to be in interference fit with the radial protrusion. When the axle shaft is axially translated so that the radial protrusion engages with the inner radial groove of the axle guide, the axle shaft can be disconnected from the vehicle's wheel hub. In this way, the vehicle wheels can be decoupled from the powertrain, and during flat towing, the axle shaft can be kept partially installed and supported.

[0006] For example, the axle guide can be formed of a material that is more flexible and resilient than a wheel axle of a vehicle, allowing the axle guide to bend and deform. However, the material of the axle guide can have sufficient rigidity to maintain the position of the axle when disconnected from the wheel hub. During towing, the wheels can rotate freely without rotating the axle, thereby preventing the transmission and the electric motor connected to the transmission from rotating. The wheels can be separated from the power system without removing and storing the axle, and without adding additional complexity and costly components to the vehicle drivetrain.

[0007] It should be understood that the above summary is provided to introduce in a simplified form 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 embodiments that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram showing an example of a vehicle power system that can be installed in an electric vehicle or a hybrid vehicle and has a detachable axle assembly.

[0009] Figure 2 Shows an example of a detachable axle assembly in a first position.

[0010] Figure 3 Shows the detachable axle assembly in a second position.

[0011] Figure 4 Shows the detachable axle assembly installed in a vehicle drivetrain.

[0012] Figure 5 Shows an example of a method of adjusting a detachable axle assembly according to an operating mode required by a vehicle. DETAILED DESCRIPTION

[0013] The following description relates to systems and methods for a vehicle axle assembly. A vehicle can include a powertrain, such as Figure 1 the powertrain shown, which can include a prime mover powered by an energy storage device. In some cases, it may be necessary to flat tow a vehicle, which can be challenging for an electric vehicle or a hybrid electric vehicle to achieve flat towing without compromising the integrity of the power system and drivetrain components. By configuring the vehicle with a detachable axle assembly that allows one or more axle shafts of the vehicle to be disconnected from the corresponding wheel hubs, this problem can be at least partially addressed. Figure 2 and Figure 3An example of a detachable axle assembly in the unlocked and locked positions is described separately, where the detachable axle assembly includes an axle guiding device that circumferentially surrounds the axle shaft. When disconnected from the wheel hub, the axle guiding device can provide mechanical support for the axle shaft and can hold the axle shaft in the desired position when the vehicle is towed. Figure 4 A detachable axle assembly connected to the wheel hub and the differential is further shown. Figure 5 A method of adjusting a separable component between the unlocked and locked positions is described, which two positions correspond to the driving mode and the towing mode of the vehicle respectively.

[0014] First look Figure 1 , the figure shows a vehicle 100 having a power system 101 and a transmission system 103. The center line 123 aligned with the longitudinal axle shaft of the vehicle 100 is marked in the figure. The powertrain includes a prime mover 106 and a transmission 108. The prime mover 106 can be an internal combustion engine and / or an electric motor, etc., and provides rotational power for the transmission 108 when operating. The transmission 108 can be any type of transmission, such as a manual transmission, an automatic transmission or a continuously variable transmission. The transmission 108 receives the rotational power generated by the prime mover 106 as input and outputs rotational power to the transmission system 103 according to the selected gear or setting.

[0015] The prime mover 106 can be powered by energy from an energy storage device 105. In one example, the energy storage device 105 is a battery for storing electrical energy. An inverter 107 can be installed between the energy storage device 105 and the prime mover 106 for adjusting direct current (DC) to alternating current (AC).

[0016] The vehicle 100 can be a commercial vehicle, a light, medium or heavy vehicle, a passenger vehicle, an off-road vehicle and / or a multi-purpose vehicle. In addition, the vehicle 100 and / or one or more of its components can also be used in the industrial, locomotive, military, agricultural and aerospace fields. In one example, the vehicle 100 is an electric vehicle.

[0017] In some examples, as Figure 1 shown, the transmission system 103 includes a first axle assembly 102 and a second axle assembly 112. At least one or more of the first axle assembly 102 and the second axle assembly 112 can be a detachable axle assembly, where the axle shafts of each axle assembly can be disconnected from the respective wheel hubs of the vehicle 100. The disconnection of the axle shaft from the wheel hub can be achieved based on the separation of the radial protrusion of the axle shaft from the inner radial groove of the axle guiding device that circumferentially surrounds the axle shaft. For example, by translating the axle shaft axially (such as along the rotational center of the axle shaft of the axle shaft), the axle shaft can be alternately connected or disconnected from the wheel hub. More details of the detachable axle assembly will be provided below with reference to Figures 2 - 4 Provide more details of the separable axle assembly.

[0018] The first axle assembly 102 can be configured to drive the first set of wheels 104, and the second axle assembly 112 can be configured to drive the second set of wheels 114. In one example, the first axle assembly 102 is disposed near the front end 150 of the vehicle 100 and thus includes a front axle, while the second axle assembly 112 is disposed near the rear end 152 of the vehicle 100 and thus includes a rear axle. The driveline 103 is shown in a four-wheel drive configuration, but other configurations can also be employed. For example, the driveline 103 can include a front-wheel drive, rear-wheel drive, or all-wheel drive configuration. Additionally, the driveline 103 can also include one or more tandem axle assemblies. Thus, without departing from the scope of the present disclosure, the powertrain 103 can also have other configurations, Figure 1 The configuration shown is for illustration only and not for limitation. Additionally, the vehicle 100 can also include other wheels that are not connected to the driveline 103.

[0019] In certain four-wheel drive configurations, such as Figure 1 shown, the driveline 103 includes a transfer case 110 that is configured to receive the rotational power output from the transmission 108. The first drive axle shaft 113 is drivingly connected to the first output 111 of the transfer case 110, and the second drive axle shaft 122 is drivingly connected to the second output 121 of the transfer case 110. The first drive axle shaft 113 (e.g., the front drive axle shaft) transfers the rotational power from the transfer case 110 to the first differential 116 of the first axle assembly 102 to drive the first set of wheels 104, while the second drive axle shaft 122 (e.g., the rear drive axle shaft) transfers the rotational power from the transfer case 110 to the second differential 126 of the second axle assembly 112 to drive the second set of wheels 114. For example, the first differential 116 is drivingly coupled to a first set of axle shafts 118 that are coupled to the first set of wheels 104, and the second differential 126 is drivingly coupled to a second set of axle shafts 128 that are coupled to the second set of wheels 114. It can be understood that, as Figure 2 shown, each of the first set of axle shafts 118 and the second set of axle shafts 128 can be disposed in a housing, such as an axle shaft tube.

[0020] In some examples, additionally or alternatively, vehicle 100 can be a hybrid vehicle, including an engine and an electric machine, each configured to provide power to one or more of the first axle assembly 102 and the second axle assembly 112. For example, one or both of the first axle assembly 102 and the second axle assembly 112 can be driven by power from the engine in a first operating mode, in which the electric machine does not operate to provide power (e.g., engine-only mode); in a second operating mode, driven by power from the electric machine, in which the engine does not operate to provide power (e.g., electric-only mode); in a third operating mode, driven by power from the engine and the electric machine (e.g., electric assist mode). As another example, one or both of the first axle assembly 102 and the second axle assembly 112 can be an electric axle assembly, configured to be driven by an integrated electric machine.

[0021] Vehicle 100 may also include a control system 14. The control system 14 receives information from a plurality of sensors 16 and sends control signals to a plurality of actuators 15. For example, the sensors 16 can include one or more wheel speed sensors 18, battery sensors 20, differential sensors 22, vehicle speed sensors 24, and at least one prime mover sensor 26. In one example, the prime mover sensor 26 can be a motor resolver, configured to provide position and speed feedback related to the motor. When the prime mover 106 includes an engine, other sensors, such as pressure, temperature, air / fuel ratio, and composition sensors, can be connected to different locations of the vehicle 100. The plurality of actuators can include motors, transmissions, and the like. The control system 14 can include a controller 12, which can receive input data from various sensors, process the input data, and trigger the plurality of actuators 15 in response to the processed input data according to instructions or codes programmed therein, which correspond to one or more routines. In particular, the controller 12 can be a microcomputer, including a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values, such as a read-only memory chip, random access memory, keep-alive memory, and a data bus.

[0022] As Figure 1As shown, when the vehicle is configured as a hybrid or electric vehicle, it may include at least one electric motor coupled to the vehicle drivetrain. In one example, the electric motor may be fixedly coupled to the drivetrain such that rotation of the electric motor drives rotation of the drivetrain. Conversely, rotation of the drivetrain may force the electric motor to rotate. In some examples, it may not be possible to adjust the vehicle's transmission to a neutral mode in which rotation of the vehicle wheels and the transmission are independent of each other. For example, one or more axle shafts may be connected to the vehicle wheels and the transmission or differential in such a way that the axle shafts cannot be disengaged from the wheels and the transmission or differential. As another example, the vehicle may be disabled such that an operator cannot adjust the transmission (e.g., via the transmission) to the neutral mode.

[0023] In some cases, it may be necessary or desirable to tow the vehicle. In cases where the transmission cannot be adjusted to the neutral mode, as described above, towing the vehicle with all wheels in contact with the ground, such as flat towing, may be precluded. Instead, towing the vehicle with the vehicle wheels off the ground may be required to maintain the integrity of the vehicle powertrain. As an alternative, the vehicle's axle shafts may be disconnected and removed to decouple the vehicle's wheels from the powertrain, enabling flat towing of the vehicle. However, disconnecting, storing, and transporting the axle shafts during towing can be inconvenient and laborious.

[0024] As an alternative to the above methods, the vehicle may have at least one detachable axle assembly. The detachable axle assembly may include at least one axially translatable (e.g., slidable) axle shaft supported by an axle guide. As Figure 1 shown by the dashed region 130 in Figure 1 , the axle guide may be positioned along the axle axis. For example, the axle guide may be coupled to at least one axle shaft of the first set of axle shafts 118 or at least one axle shaft of the second set of axle shafts 128. In some examples, the axle guide may be connected to each axle shaft of the vehicle. Additionally, the position of the axle guide along each axle shaft may be different from the position shown by the dashed region 130 in

[0025] When the axle shaft is axially translated relative to the axle guide device to the unlocked configuration, the connection between the axle shaft and the wheel hub can be maintained, which may be applicable when the vehicle is traveling, for example, in the driving mode. When the axle shaft is axially translated relative to the axle guide device to the locked configuration, the flange at the end of the axle shaft can be moved away from the wheel hub, thereby allowing a gap to exist between the end of the axle shaft and the wheel hub. In the locked configuration, the wheel hub can rotate without causing the power train to rotate. Therefore, the vehicle can be adjusted between the driving mode and the traction mode of the power transmission system, with the former realizing the unlocked configuration of the detachable axle assembly and the latter realizing the locked configuration of the detachable axle assembly.

[0026] Figure 2 and Figure 3 An example of a detachable axle assembly 200 of a vehicle (such as the vehicle 100 in Figure 1 ) is described in the form of a partial cross-sectional view. The separable axle assembly 200 is in the first unlocked configuration in Figure 2 and in the second locked configuration in Figure 3 . A set of reference axle shafts 201 are provided in the figure, representing the x-axle shaft, the y-axle shaft, and the z-axle shaft respectively. In one example, the Y-axle shaft is parallel to the direction of gravity, and the Z-axle shaft is parallel to the central rotating axle shaft 202 of the detachable axle shaft assembly 200. In addition, Figure 2 also marks the first axial direction (such as the inner direction 203) and the second axial direction (such as the outer direction 205). The inner direction 203 can be the direction towards the center line of the vehicle (such as the center line 123 in Figure 1 ), and the outer direction 205 can be the direction away from the center line of the vehicle.

[0027] The detachable axle assembly 200 includes an axle shaft 204, an axle tube 206 that encloses the axle shaft 204, and an axle guide rail 208. In one example, the axle shaft tube 206 can be a differential tube extending from the differential housing. In another example, the axle shaft tube 206 can be a tube extending from the transmission housing. The axle shaft tube 206 can be fixedly connected to the corresponding housing and does not rotate.

[0028] The axle shaft 204 can include Figure 1in one or more of the first and second sets of axle shafts 118 and 128 (e.g., axle shaft 204 is a non-limiting example of one or more axle shafts in the first set of axle shafts 118 and the second set of axle shafts 128). The axle shaft tube 206 can be a sleeve that surrounds the axle shaft 204 in a circumferential and concentric direction but is spaced from the axle shaft 204. For example, the inner surface 210 of the axle shaft tube 206 may not contact the outer surface 212 of the axle shaft 204. As described above, the axle shaft tube 206 can be fixedly connected to the housing of the driveline or powertrain component and remain stationary. When the axle shaft rod 204 rotates, the axle shaft rod 204 can rotate within the axle shaft tube 206.

[0029] The outer surface 212 of the axle shaft 204 can include an outwardly protruding radial projection 214 that extends away from the center of the disconnect axle assembly 200 to rotate the axle shaft 202. In one example, the radial projection 214 can be integrated into the structure of the axle shaft. For example, during the manufacturing process, the axle shaft 204 can be integrally formed with the radial projection 214. In other examples, the radial projection can be fixedly connected to the outer surface 212 of the axle shaft 204, such as by a press fit connection or welding. The radial projection 214 can extend around the entire circumference of the axle shaft 204 or only around a portion of the circumference of the axle shaft 204.

[0030] The axle shaft 204 can extend between the driveline components of the vehicle and the wheel hub. For example, the axle shaft 204 can be connected to a transmission or differential at a first end (e.g., along the inner direction 203) and to a wheel hub at a second opposite end (e.g., along the outer direction 205). The first end can include splines, and the second end can include a flange, as Figure 4 shown and will be further described below.

[0031] The shaft guide 208 can be disposed between the axle shaft 204 and the axle shaft tube 206 and can be surrounded by the axle shaft tube 206. In one example, as described above, the shaft guide 208 can be positioned at the location shown by the dashed area 130 in Figure 1 The shaft guide 208 can be an improved version of a device for guiding the installation of the axle shaft 204 into the axle shaft tube 206. For example, the shaft guide 208 can include an inner radial groove 226 for receiving the radial projection 214 of the axle shaft 204.

[0032] The axle guide 208 can be in contact with the axle shaft 204 and the axle shaft tube 206 respectively, so that the outer surface 212 of the axle shaft 204 can be separated from the inner surface 210 of the axle shaft tube 206 by the axle guide 208. For example, the axle guide 208 can have a first flared portion 216 surrounding the axle shaft 204 and a second cylindrical portion 218 in contact with the axle shaft tube 206. The flared portion 216 can be continuous with the cylindrical portion 218 to form a single continuous unit.

[0033] The flared portion 216 can include a sleeve 220 and a cone 222. The sleeve 220 can extend along a partial length of the axle shaft, which is determined along the Z axle shaft. The inner surface 224 of the sleeve 220 can include inner radial grooves 226. The inner radial grooves 226 can extend around the circumference of the axle guide 208 or at least a portion thereof, and their shape can match the geometry of the radial protrusions 214 of the axle shaft 204. In other words, the inner radial grooves 226 can be configured to receive the radial protrusions 214 and cooperate with the radial protrusions 214, so that the inner radial grooves 226 and the radial protrusions 214 have an interference fit to inhibit the movement of the axle shaft 204 in any direction.

[0034] As Figure 2 shown, the inner diameter 207 of the sleeve 220 can be greater than the diameter 209 of the axle shaft 204. The outer surface 212 of the axle shaft 204 can not be in contact with the inner surface 224 of the sleeve 220. Instead, the inner surface 224 of the sleeve 220 can be away from the outer surface 212 of the axle shaft 204 and concentric with the axle shaft tube 206, whether the detachable axle assembly 200 is in the locked or unlocked position. When the detachable axle assembly 200 is in the unlocked position (e.g., as Figure 2 shown), the concentric alignment of the axle shaft 204 with the axle tube 206 can be maintained by coupling the first end of the axle shaft 204 to a drivetrain or power system component and coupling the second end of the axle shaft 204 to a wheel hub (as Figure 4 shown). When the detachable axle assembly 200 is in the locked position (e.g., as Figure 3 shown), the concentric alignment of the axle shaft 204 with the axle shaft tube 206 can be supported by the wheel hub and the interference fit between the radial protrusions 214 of the axle shaft 204 and the inner radial grooves 226 of the axle guide 208.

[0035] The cone 222 of the axle guide 208 can extend from one end of the sleeve 220 to one end of the cylindrical portion 218 and be angled with respect to the rotational center axle 202. For example, the angle of the cone 222 can be 45 degrees relative to the rotational center axle 202. In other examples, the angle can be in the range of 30 - 60 degrees. The diameter 228 of the cone 222 can increase from the end of the sleeve 220 to the end of the cylindrical portion 218. The cone 222 can be a hollow structure and can be open at the widest end of the cone 222. In other examples, the cone 222 includes an end wall with a central opening through which the axle 204 can extend.

[0036] The cylindrical portion 218 of the axle guide 208 can extend parallel to the Z-axle in the inner direction 203, away from the widest end of the cone 222. The cylindrical portion 218 can have an outer diameter 232 equal to the inner diameter of the axle tube 206, which in some examples can also provide an interference fit. For example, the cylindrical portion 218 can include an outer surface 234 that is coplanarly in contact with the inner surface 210 of the axle tube 206. As Figure 2 and Figure 3 shown, the cylindrical portion 218 of the axle guide 208 can have a length determined along the Z-axle that is less than the length of the flared portion 216 and greater than the length of the tapered portion 222. In other examples, the length of the cylindrical portion 218 of the axle guide 208 can be different from the Figure 2 and Figure 3 lengths described therein. For example, the cylindrical portion 218 can be shorter or longer than the length shown in the figure, and / or can be longer than the flared portion 216.

[0037] The axle guide 208 can be made of a material that has sufficient flexibility when the axle rod 204 is translated axially (e.g., along the Z-axle) to allow the inner diameter 207 of the sleeve 220 to expand, such that when a force is applied to force the axial translation, the radial protrusion 214 can slide within the axle guide 208 and press outward against the inner surface 224 of the sleeve 220. For example, the axle guide 208 can be made of plastic or rubber. In one example, the axle guide 208 can be a continuous, single structure made entirely of a common material. In another example, the flared portion 216 can be formed of a material different from that of the cylindrical portion 218, and the two portions can be fixedly connected by welding. When formed of different materials, the cylindrical portion 218 can be formed of a harder material than the flared portion 216. Additionally, in some examples, the outer surface 234 of the cylindrical portion 218 can be textured to increase the friction between the outer surface 234 of the cylindrical portion 218 and the inner surface 210 of the axle tube 206.

[0038] In one example, the detachable axle assembly 200 is configured to allow the axle shaft 204 to be adjusted between an unlocked position (as shown in Figure 2 ) during vehicle operation in a drive mode and a locked position (as shown in Figure 3 ) during vehicle operation in a tow mode. In the unlocked position, the axle shaft 204 moves along the inner direction 203 relative to the locked position in Figure 3 . For example, the axle shaft 204 can be axially translated along the inner direction 203 until the radial protrusion 214 of the axle shaft 204 passes by the shaft guide 208 and is located inside it. When the radial protrusion 214 is located inside the shaft guide 208, the radial protrusion 214 no longer abuts against the inner surface 224 of the sleeve of the shaft guide 208. In other words, when the detachable axle assembly 200 is in the unlocked position, the radial protrusion 214 is located outside the shaft guide 208 and between the shaft guide 208 and the powertrain component to which the axle shaft 204 is connected.

[0039] In addition, in the unlocked position of the detachable axle assembly 200, the axle shaft 204 moves far enough in the inner direction 203 such that, for example, when the radial protrusion 214 is located inside the inner end 236 of the shaft guide 208, the flange (engaging with the wheel hub) at the second end of the axle shaft 204 abuts against the wheel hub.

[0040] For example, Figure 4 the detachable axle assembly 200 shown is installed in the vehicle's driveline and is in the unlocked position corresponding to Figure 2 . The inner end 402 of the axle shaft 204 is connected to the differential 404, and the outer end 406 is connected to the wheel hub 408. The axle shaft tube 206 is fixedly connected to the housing 410 of the differential 404 and the wheel hub 408. The radial axle shaft 214 of the axle shaft 204 is located inside the shaft guide 208.

[0041] At the inner end 402 of the axle shaft 204, the axle shaft 204 has a plurality of splines configured to cooperate with the side gears 412 of the differential 404. When the detachable axle assembly 200 is in the unlocked position, the plurality of splines can be interlocked with the side gears 412, but the interface between the plurality of splines and the side gears 412 is not fixed. For example, the axle shaft 204 can slide away from the differential 404 along the outer direction 205, disengaging the plurality of splines from the side gears 412 without operating the fastening means at the inner end 402 of the axle shaft 204 or the differential 404.

[0042] At the outer end 406 of the axle shaft 204, the axle shaft has a flange 414 that has openings for receiving fastening means such as bolts. The flange 414 may project outside the wheel hub 408 such that when the detachable axle assembly 200 is in the unlocked position and the splines at the inner end 402 of the axle shaft 204 engage the side gears 412, the inner (e.g., medial) surface of the flange 414 abuts the wheel hub. The positioning of the flange 414 relative to the wheel hub 408 inhibits further inward translation of the axle shaft 204 beyond the unlocked position.

[0043] When the detachable axle assembly 200 is in Figure 4 the unlocked position shown, the flange 414 may contact the wheel hub 408 and the openings of the flange 414 may be aligned with the bolt joints 416 of the wheel hub 408. The flange 414 may be fixed to the wheel hub 408 by fastening bolts on the bolt connection 416, thereby fixing the axle shaft 204 to the wheel hub 408. Thereby inhibiting axial sliding of the axle shaft 204. Under the forced action of the differential 404, the rotation of the axle shaft 204 may be transferred to the wheel hub 408. Further, when the axle shaft 204 rotates, the axle shaft 204 may not contact the shaft guide 208.

[0044] When the detachable axle assembly 200 is in Figure 3 the locked position shown, relative to Figure 2 the unlocked position shown, the axle shaft 204 moves along the outer direction 205. The axle shaft 204 may move axially, e.g., along the rotational center axle shaft 202, forcing the sleeve 220 of the shaft guide 208 to bend and increase its inner diameter to accommodate the increased diameter of the axle shaft 204 at the radial projection 214 as the radial projection 214 is pulled along the shaft guide 208 over the distance 238 between the inner end 236 of the shaft guide 208 and the inner radial slot 226 of the shaft guide 208. When the radial projection 214 is inserted into the inner radial slot 226 of the shaft guide 208, the axial translation of the axle shaft 204 into the locked position may terminate. When the radial projection 214 is located within the radial inner slot 226, the expansion of the inner diameter of the sleeve 220 of the shaft guide 208 may stop, allowing the material of the sleeve 220 of the shaft guide 208 to relax.

[0045] The rigidity of the material of the flared portion 216 of the axle guide 208 can inhibit further axial translation, e.g., translation along the inner or outer directions 203, 205, thereby positioning the radial projection 214 outside the inner radial groove 226. The axle 204 can further axially translate only when the force applied along the Z axle is sufficient to overcome the rigidity of the flared portion 216 of the axle guide 208 and push the radial projection 214 out of or into the inner radial groove 226. In other words, the applied force must be at least large enough to force the sleeve 220 of the axle guide 208 to bend and expand in diameter due to the radial projection 214 abutting against the inner surface 224 of the axle guide 208.

[0046] When the radial projection 214 is located in the inner radial groove 226, there can be a gap between the flange at the second end of the axle 204 and the wheel hub. In one example, the gap can be at least the distance at which the flange of the axle 204 no longer contacts the wheel hub. In another example, as Figure 4 shown, the gap can correspond to the distance 418 by which the axle 204 moves in the outer direction 205, away from the differential 404, to disengage the multiple splines on the inner end 402 of the axle 204 from the side gear 412 of the differential 404. Before adjusting the separable axle assembly 200 to the locked position, the bolts can be removed from the bolt connection 416 of the wheel hub 408. Thus, the axle guide 208 can be positioned along the axle tube 206 such that when the separable axle assembly 200 is adjusted to the locked position, the axle 204 moves in the outer direction 205, moving at least the distance 418 relative to the unlocked position. As described above, in the locked position, the radial projection 214 of the axle 204 can be inserted into the inner radial groove 226 of the axle guide 208, and the position of the axle 204 can be locked in place by the interference fit between the radial projection 214 and the inner radial groove 226.

[0047] When the wheel axle 204 moves a distance 418 to disengage the wheel axle 204 from the side gear 412 of the differential 404, the flange 414 on the outer end 406 of the wheel axle 204 also moves away from the wheel hub 408 in the outer direction 205 at the same time. In this way, the flange 414 of the wheel axle 204 moves away from the wheel hub 408, allowing the wheel hub to rotate freely without driving the wheel axle 204 to rotate.

[0048] Therefore, when the vehicle is being towed and all wheels remain in contact with the ground, the separable axle assembly 200 can be adjusted to the locked position to disconnect the wheel hub 408 from the axle 204. When the vehicle is being towed, the corresponding wheels of the vehicle can rotate freely without forcing the axle to rotate. Thus, the vehicle powertrain is disengaged from the wheels and does not rotate with the wheels.

[0049] Although the axle shaft 204 is disconnected from the wheel hub 408 at the outer end 406, the position of the axle shaft 204 relative to the vehicle can be maintained by the axle guide 208. For example, as described above, even if the axle shaft 204 is aligned with the wheel hub 408 and the driveline or powertrain components (e.g., the side gears 412 of the differential 404) along the Z axle shaft, it can remain unchanged. When the inner end 402 of the axle shaft 204 is not supported by a connection to the powertrain or powertrain components, the axle guide 208 can be used as a support device to hold the axle shaft 204 in place.

[0050] In addition, an interference fit between the radial protrusion 214 of the axle shaft and the inner radial groove 226 of the axle guide can reduce further axial translation of the axle shaft 204 or accidental movement of the axle shaft 204. For example, the rigidity of the material of the axle guide 208 can minimize the bounce of the axle shaft, such as bounce in a direction orthogonal to the rotational center axle shaft 202, and prevent the axle shaft 204 from hitting the axle tube 206 when the vehicle is towed. Therefore, when it is necessary to flat-tow the vehicle, it is not necessary to disassemble or otherwise manipulate the axle shaft 204. Instead, the axle shaft 204 can remain partially installed (e.g., remain within the axle tube 206) without transferring the rotation of the wheels to the vehicle's power system. In addition, when the axle shaft 204 is disconnected from the wheel hub 408, the alignment of the axle shaft 204 with the wheel hub 408 can be maintained, and when the vehicle needs to operate in a drive mode, the axle shaft 204 can be easily reconnected to the wheel hub 408 (and the driveline / powertrain assembly).

[0051] Figure 5 An example of a method 500 is shown for adjusting the driveline of a vehicle between a tow mode and a drive mode. In one example, the vehicle can be the Figure 1 vehicle 100 therein, and can have a detachable axle assembly, such as the Figures 2 - 4 detachable axle assembly 200 therein, which is coupled to at least one axle shaft of the vehicle. By way of example, the vehicle can have a transmission that does not include a neutral mode in which the powertrain is disconnected from the vehicle wheels. Alternatively, the vehicle can be disabled such that adjustment of the neutral mode cannot be made at the transmission of the transmission, etc. The method can be performed by an operator, such as a driver or a tow truck operator, and at least some steps of the method can be performed with the assistance of data output by vehicle sensors (e.g., the sensors described with reference to Figure 1 ).

[0052] At 502, the method includes determining an operating mode of a vehicle driveline. For example, when one or more axle shafts of the vehicle are disengaged from corresponding wheel hubs of the vehicle (e.g., corresponding detachable axle assemblies are in an unlocked position), the driveline may be in a traction mode. When the driveline is in the traction mode, the axle shafts may also be disengaged from driveline components (e.g., a differential or transmission). When one or more axle shafts are respectively connected to respective wheel hubs and corresponding driveline or driveline components, the driveline may be in a drive mode.

[0053] In one example, the operating mode of the vehicle may be determined based on signals from one or more sensors of the vehicle. For example, when at least one wheel is disconnected and a control system (such as Figure 1 When the control system 14 in is activated, the wheel speed sensor (such as Figure 1 Data received from the wheel speed sensors 18 in the vehicle may indicate that the corresponding wheel is disconnected. For example, a notification may be issued to the operator that one or more wheel speed sensors are not detecting a signal, which may be due to the detector of the wheel speed sensor being out of range of the wheel speed sensor signal generating device. As another example, the operating mode of the vehicle may be based on a motor resolver coupled to the vehicle motor (such as Figure 1 For example, the signal from the motor resolver can be compared with the signal from a differential sensor (such as Figure 1 If the signal from the motor resolver indicates that the movement of the motor does not correlate with the movement detected by the differential sensor, a notification can be given to the operator indicating that the vehicle's powertrain is disconnected from the drivetrain.

[0054] Additionally, operators can determine the driveline's operating mode based on visual inspection. For example, observing that the fasteners connecting the axle shaft to the wheel hub have been removed, or that the flange on the outer end of the axle shaft is spaced from the wheel hub, may indicate that the driveline is in traction mode. Conversely, when all of the vehicle's axle shafts are connected to the wheel hub and the fasteners are in place, it indicates that the axle shafts are engaged with the wheel hub and the respective powertrain / driveline components. Therefore, the driveline may be in drive mode.

[0055] At 504, the method includes determining whether a drive mode or a towing mode of the powertrain is desired. For example, the drive mode may be desired when the operator desires to drive the vehicle. Another example is that the towing mode may be desired when the vehicle is to be towed, such as by flat towing. If it is desired to operate the vehicle powertrain in the towing mode, the method proceeds to 506 where at least one disengageable axle assembly is adjusted to a locked position, such as Figure 3The locked position described in. For example, an operator can remove the fastener (such as a bolt) that fixes an axle shaft of a detachable axle assembly to the corresponding wheel hub, and pull the axle shaft in the outer direction until the radial protrusion of the axle shaft is inserted into the inner radial groove of the shaft guiding device of the detachable axle assembly. For example, the operator can grasp the outer end of the wheel axle shaft, such as Figure 4 the flange 414 protruding outside the wheel hub in, and / or use a tool to pull the wheel axle shaft in the outer direction. The position of the shaft guiding device along the axle shaft tube (such as Figure 2 and Figure 3 the axle shaft tube 206 in) can be configured to disengage the axle shaft from the corresponding drivetrain or powertrain component in addition to disconnecting from the wheel hub. In other words, there are gaps between the axle shaft and the differential or transmission, as well as between the axle shaft and the wheel hub. By separating the axle shaft from the drivetrain / powertrain component, the rotation of the axle shaft can be reduced, which may otherwise cause degradation of the drivetrain components, such as the situation where the operator starts the powertrain rotation without knowing that the drivetrain is in the traction mode.

[0056] When the radial protrusion is inserted into the inner radial groove, the interference fit between the radial protrusion and the inner radial groove can maintain the axial position of the axle shaft, while the rigidity of the axle shaft can reduce the movement of the axle shaft in other directions. Therefore, the shaft guiding device supports and bears the axle shaft. In other examples, the powertrain may have been adjusted to the traction mode, so it may not be necessary to adjust the detachable axle assembly (or assemblies). The method returns to the starting point.

[0057] If it is desired to operate the vehicle drivetrain in the drive mode, the method continues from 504 to 508, where at least one detachable axle assembly is adjusted to the unlocked position, as Figure 2 and Figure 4 shown. For example, an operator can push the axle shaft of the detachable axle assembly in the inner direction to release the radial protrusion of the axle shaft from the inner radial groove of the axle shaft guide slot. The operator can continue to push the axle shaft against the rigidity of the shaft guiding device until the radial protrusion is no longer enclosed within the shaft guiding device. The radial protrusion can be located inside the shaft guiding device, and the inner end of the axle shaft can engage with the powertrain or powertrain component. The flange at the outer end of the axle shaft can contact the wheel hub so as to insert and tighten the fastener to fix the flange to the wheel hub. Alternatively, the detachable axle assembly may have been adjusted to the drive mode, so it may not be necessary to adjust the detachable axle assembly (or assemblies).

[0058] In this way, the powertrain of the vehicle can be configured as a flatbed trailer without completely unloading and disassembling the vehicle axle shafts. In particular, for vehicles that do not have the ability to adjust the vehicle transmission to the neutral mode, or in cases where it is not possible to adjust to the neutral mode, the axle shafts can be disconnected from at least the wheels of the vehicle through a detachable axle assembly, but remain partially installed. For example, the axle shafts can remain aligned with the wheels at the outer ends and with the corresponding driveline or powertrain components at the inner ends, while allowing the vehicle wheels to rotate freely without forcing the vehicle powertrain to rotate. In some examples, the separable axle assembly also allows the axle shafts to be separated from the vehicle powertrain. The detachable axle assembly can include an axle guide that can be used for the initial guidance of the insertion of the axle shafts during vehicle assembly, and the axle guide has an inner radial groove. The geometry of the inner radial groove can match the geometry of the radial protrusions of the axle shafts. When the radial protrusions mate with the radial grooves, the resulting interference fit can maintain the alignment (but disconnection) of the axle shafts with the wheels and the driveline or powertrain components, while suppressing the movement of the axle shafts. Thus, the vehicle can be ready for flat towing at any time without incurring additional costs, system complexity, or inconvenient disassembly and storage of the axle shafts.

[0059] Figures 2 - 4 An example configuration showing the relative positioning of various components is presented. If the elements shown in the figures are in direct contact or directly coupled to each other, then in at least one example, these elements can be referred to as being in direct contact or directly coupled, respectively. Similarly, in at least one example, elements shown as being contiguous or adjacent to each other can be contiguous or adjacent to each other, respectively. For example, elements in face-to-face contact with each other can be referred to as face-to-face contact elements. Another example is that in at least one example, elements that are placed separately from each other with only space in between and no other elements can be referred to as being placed separately from each other. Also, elements shown above / below each other, on opposite sides of each other, or on the left / right side of each other relative to each other can be referred to as such elements. Additionally, as shown in the figures, 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. The top / bottom, upper / lower, above / below used herein can be relative to the vertical axle shaft in the figure and are used to describe the relative positioning of the elements in the figure with respect to each other. Thus, in one example, an element shown above other elements is vertically positioned above the other elements. For another example, the shapes of the elements depicted in the figures can be referred to as having those shapes (e.g., circular, straight, planar, curved, rounded, chamfered, beveled, or similar shapes). Additionally, in at least one example, elements shown intersecting each other can be referred to as intersecting elements or intersecting each other. Further, in one example, an element shown inside another element or shown outside another element can be referred to as such an element. Figures 2 - 4 Shown approximately to scale.

[0060] The present disclosure also provides a support member for a powertrain of a vehicle, including: an axle shaft having a radial protrusion protruding from an outer surface of the axle shaft; an axle shaft guide that circumferentially surrounds the axle shaft and has an inner radial groove configured to be in interference fit with the radial protrusion, wherein when the axle shaft translates axially to engage the radial protrusion with the inner radial groove of the axle shaft guide, the axle shaft is disconnected from a wheel hub of the vehicle (e.g., when the axle shaft is disconnected from the wheel hub and the axle shaft translates axially, the radial protrusion engages with the inner radial groove). In a first example of the system, when the axle shaft is disconnected from the wheel hub, the axle shaft is also disengaged from a powertrain component or a power system component, wherein the axial direction is an outer direction, and the axial translation of the axle shaft in the outer direction to disengage the axle shaft from the wheel hub is relative to the position of the axle shaft when the powertrain is in a driving mode. In a second example of the system (optionally including the first example), the axle shaft is enclosed within an axle shaft tube, and the axle shaft guide is disposed between an inner surface of the axle shaft tube and an outer surface of the axle shaft. In a third example of the system, optionally including one or both of the first and second examples, the axle shaft guide has a cylindrical portion and a flared portion, and the cylindrical portion and the flared portion form a continuous single unit, wherein the axle shaft guide is formed of a material that is more flexible than the axle shaft. In a fourth example of the system, optionally including one or more or each of the first to third examples, the cylindrical portion of the axle shaft guide is in coplanar contact with the inner surface of the axle shaft tube. In a fifth example of the system, optionally including one or more or each of the first to fourth examples, the flared portion circumferentially surrounds the axle shaft, and an inner surface of the flared portion is spaced apart from and does not contact the axle shaft. In a sixth example of the system, optionally including one or more or each of the first to fifth examples, the inner radial groove of the axle shaft guide is disposed along an inner surface of the flared portion of the axle shaft guide. In a seventh example of the system, optionally including one or more or each of the first to sixth examples, when the axle shaft is connected to the wheel hub, the radial protrusion of the axle shaft is located inside the axle shaft guide. In an eighth example of the system, optionally including one or more or each of the first to seventh examples, when translating axially to engage the radial protrusion with the inner radial groove of the axle shaft guide, a gap is formed between the wheel hub and an outer end of the axle shaft.

[0061] The present disclosure also provides support for a method of disconnecting an axle shaft from a vehicle powertrain, the method comprising: axially translating the axle shaft in an outward direction, the axle shaft being circumferentially surrounded by an axle shaft guide having an inner radial groove to engage a radial protrusion of the axle shaft with the inner radial groove of the axle shaft guide, wherein when the radial protrusion disengages from the inner radial groove, the axle shaft is disconnected from the wheel hub (e.g., when the axial protrusion disengages from the inner radial groove, the axle shaft is disconnected from the wheel hub), the method may include disconnecting the axle shaft from the wheel hub to facilitate axial translation of the axle shaft). In a first example of the method, the bolts securing the axle shaft to the wheel hub are removed prior to axially translating the axle shaft. In a second example of the method (optionally including the first example), when axially translating, a radial wedge of the axle shaft presses against the inner surface of the shaft guide device until the radial wedge is inserted into the inner radial groove. In a third example of the method, optionally including one or both of the first and second examples, the wheel axle shaft is axially translated a distance in an outward direction such that the inner end of the wheel axle shaft is disengaged from a driveline or powertrain component. In a fourth example of the method, optionally including one or more or each of the first to third examples, when the radial protrusion of the wheel axle shaft engages the inner radial groove of the shaft guide device, the wheel hub rotates independently of the wheel axle shaft. In a fifth example of the method, optionally including one or more or each of the first to fourth examples, the method further comprises: axially translating the axle shaft in an inward direction relative to the position of the axle shaft when the radial protrusion of the axle shaft engages the inner radial groove of the axle shaft guide to effect connection of the axle shaft to the wheel hub, wherein when the axle shaft is connected to the wheel hub, the radial protrusion is located inside the axle shaft guide.

[0062] The present disclosure also provides a support device for a vehicle, comprising: an electric motor coupled to a transmission system of the vehicle, the transmission system including: an axle shaft having a radial axle shaft, an axle shaft tube surrounding the axle shaft, and an axle shaft guide disposed between an inner surface of the axle shaft tube and an outer surface of the axle shaft, the axle shaft guide having an inner radial groove configured to receive the radial axle shaft of the axle shaft, wherein when the radial axle shaft of the axle shaft is inserted into the inner radial groove of the axle shaft guide, a wheel hub of the vehicle rotates independently of the electric motor. In a first example of the system, the shaft guide device has a flange portion including a sleeve and a cone, the cone including an inner radial groove, wherein an inner diameter of the cone is greater than a diameter of the axle shaft. In a second example of the system, optionally including the first example, the cone is coupled to a cylindrical portion of the shaft guide device in a region where the diameter of the cone is widest, wherein an outer diameter of the cylindrical portion is equal to an inner diameter of the axle shaft tube. In a third example of the system, optionally including one or both of the first and second examples, when the axle shaft rod is connected to the wheel hub, the axle shaft rod rotates within the shaft guide device without contacting the shaft guide device. In a fourth example of the system, optionally including one or more or each of the first to third examples, the shaft guide device is close to an inner end of the axle shaft and holds the position of the inner end of the axle shaft when the axle shaft is disconnected from the wheel hub.

[0063] In another formulation, the transmission system of the vehicle includes a shaft guide device formed of a deformable material that supports an inner end of the axial axle shaft when the axial axle shaft is disconnected from a differential or a transmission of the vehicle. In a first example of the power transmission system, the shaft guide device contacts the axle shaft only at a radial projection of the axle shaft when the radial projection is inserted into an inner radial groove of the shaft guide device. A second example of the transmission system optionally includes the first example and further includes that the axle shaft does not contact the axle shaft when the axle shaft is disconnected from the differential or the transmission. A third example of the transmission system optionally includes one or more of the first and second examples and further includes: when a radial projection of the axle shaft is inserted into an inner radial groove of the axle shaft guide, rotation of a wheel hub (configured to engage with the axle shaft) of the transmission system is not transmitted to the electric motor of the vehicle.

[0064] In another formulation, a method for flat towing a vehicle includes disconnecting the wheel hub from the vehicle electric motor by axially moving an axle shaft connected to the wheel hub until a radial projection of the axle shaft is inserted into an inner radial groove of a shaft guide device.

[0065] Note that the control and estimation routine examples included herein can be used for various engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in a non-transitory memory and executed by a control system including a controller in conjunction with various sensors, actuators, and other engine hardware. The specific routines described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc. Accordingly, the various actions, operations, and / or functions illustrated can be executed in the illustrated order, in parallel, or in some cases omitted. Similarly, the order of processing is not necessarily required to implement the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the actions, operations, and / or functions illustrated can be repeated according to the particular strategy used. Further, the actions, operations, and / or functions described can be graphically represented as code to be programmed into the non-transitory memory of a computer-readable storage medium in an engine control system, where the described actions are implemented by execution of instructions in a system including various engine hardware components in combination with an electronic controller.

[0066] It is to be understood that the configurations and routines disclosed herein are exemplary in nature and these specific embodiments are not limiting since there can be many variations. For example, the above techniques can be applied to V-6, I-4, I-6, V-12, opposed 4, and other types of engines. 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.

[0067] The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to "a" element or "a first" element or the equivalent thereof. These claims are to be understood to include one or more such elements, neither requiring nor precluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and / or characteristics can be claimed by modifying this claim or presenting new claims in this or a related application. These claims, whether broader, narrower, the same, or different in scope from the original claims, are also regarded as included in the subject matter of the present disclosure.

Claims

1. A transmission system for a vehicle, characterized in that: include: An axle shaft, wherein the outer surface of the axle shaft has a radial protrusion; as well as an axle guide surrounding the axle shaft, the axle guide having an inner radial groove that is interference fit with the radial protrusion, When the axle shaft is translated in the axial direction so that the radial protrusion is engaged with the inner radial groove of the shaft guide device, the axle shaft is disconnected from the vehicle wheel hub.

2. The transmission system according to claim 1, characterized in that: When the axle shaft is disconnected from the wheel hub, the axle shaft is also disengaged from the driveline component or driveline component, wherein the axial direction is an outboard direction, and the axial translation of the axle shaft along the outboard direction causes the axle shaft to disengage from the wheel hub relative to the position of the axle shaft when the driveline is in a driving mode.

3. The transmission system according to claim 1, characterized in that: The axle shaft is enclosed in an axle shaft tube, and the shaft guide is arranged between the inner surface of the axle shaft tube and the outer surface of the axle shaft.

4. The transmission system according to claim 1, characterized in that: The shaft guide has a cylindrical portion and a flared portion, the cylindrical portion and the flared portion forming a continuous whole, and the shaft guide is made of a more flexible material than the axle shaft.

5. The transmission system according to claim 4, characterized in that: The cylindrical portion of the axle guide is in coplanar contact with the inner surface of the axle tube.

6. The transmission system according to claim 4, characterized in that: The flared portion circumferentially surrounds the axle shaft, and an inner surface of the flared portion is spaced apart from and does not contact the axle shaft.

7. The transmission system according to claim 6, characterized in that: The inner radial groove of the shaft guide is arranged along the inner surface of the flared portion of the shaft guide.

8. The transmission system according to claim 1, characterized in that: When the axle shaft is connected to the wheel hub, the radial projection of the axle shaft is located on the inner side of the shaft guide.

9. The transmission system according to claim 1, characterized in that: When axial translation causes the radial projection to engage with the inner radial groove of the shaft guide, a gap is formed between the wheel hub and the outer end of the axle shaft.

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