The present disclosure relates to an axle assembly with a wheel hub system that is configured to attach to a torque coupling and a wheel end disconnect device, in different configurations.
Vehicle drivetrains utilize drive axles to deliver mechanical power to drive wheels. Certain manufacturers have produced aftermarket torque interruption devices available to end-users for drive axle modification. Other drive axles have been designed with torque interruption capabilities by the axle manufacturer.
The inventors have recognized several issues with the abovementioned drive axles. For instance, previous aftermarket torque interruption devices have demanded complex and laborious installation procedures and may be costly to manufacture, in some cases. Further, previous drive axles with torque interruption capabilities may not be desired by many end-users. Additionally, certain previous torque interruption devices may be complex and difficult to access for servicing, repair, and replacement. Drive axles in electric vehicles (EVs) without torque interruption capabilities experience back electromotive force (EMF) during towing. The back EMF has the potential to degrade some motor components. More generally, the inventors have recognized that greater adaptability with regard to wheel end construction is desirable in vehicle powertrains. To prevent back EMF generation, the EV may be placed on a flatbed trailer during towing. However, this type of towing may be costly and impractical for certain types of vehicles such as larger vehicles, for example.
The inventors have recognized the abovementioned issues and developed a wheel hub system to at least partially overcome these issues. In one example, the wheel hub system includes an outer bearing assembly with an inner race coupled to a hub body. The wheel hub system further includes a wheel flange configured to removably coupled to the hub body. The wheel hub system even further includes an inner bearing with an outer race that is coupled to the hub body and an inner race that is coupled to a shaft. In the wheel hub system, the hub body includes interior splines which circumferentially surround exterior splines on the shaft. In this way, the system's adaptability is increased by allowing couplings and other devices to be quickly and efficiently attached to the wheel hub system via the splined interfaces. For instance, in one example, the interior splines are configured to removably couple to a hub lock device configured to inhibit mechanical power transfer therethrough when unlocked, in a first configuration. In a second configuration, the interior splines are configured to removably couple to a torque coupling. In this way, both the torque coupling and the hub lock device are able to be effectively coupled to the wheel hub system. Consequently, a drive axle in which the wheel hub system is incorporated is able to be adapted for use in a wider range of vehicle platforms and by the end-user to achieve hub locking functionality. Customer appeal is increased as a result.
Further, in one example, the hub body includes a fastener joint that is configured to receive multiple fasteners that extend through the hub lock device in the first configuration, and through the torque coupling in the second configuration. In this way, the connection between the torque coupling and the hub lock device is further strengthened with a joint that is easily accessible by manufacturing personnel, mechanics, end-users, and the like.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely 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.
A wheel hub system in an axle assembly is described herein which achieves increased adaptability by enabling the wheel hub system to be quickly and efficiently adapted for both continuous torque lock and wheel end disconnect capabilities. To achieve this functionality, the wheel hub system includes a hub body with a female spline that surrounds male splines on a shaft. A gap formed between the female splines and the male splines allows the system to be effectively coupled to torque couplings and hub locker devices, in different configurations. The wheel hub system may further include a fastener joint that allows fasteners to securely and removably attach the torque couplings and the hub locker devices to the hub body. The fastener joint may be positioned at an outboard side of the system, allowing for simplified tooling when installing and removing the torque couplings and the hub locker devices.
The vehicle 100 includes a powertrain 102 with a prime mover 106 (e.g., an internal combustion engine and/or an electric motor) and a transmission 104 (e.g., gearbox), in some instances. Specifically, in one example, the vehicle may be an electric vehicle (EV) such as an all-electric vehicle or a hybrid electric vehicle (HEV). In either EV example, the powertrain 102 includes an electric drive unit with a traction motor. To elaborate, the electric drive unit may be an electric axle, in one specific example, which is expanded upon herein.
In the illustrated example, the prime mover 106 delivers mechanical power to the transmission 104 during powertrain operation. In the EV example, power may flow from the transmission to the electric motor while the motor is operated as a generator during regeneration operation. In other examples, the prime mover 106 may deliver power directly to one or more drive axles.
Further, in the illustrated example, the transmission 104 is mechanically coupled to a drive axle assembly 110. In the illustrated example, the drive axle assembly 110 may include a differential 112, shafts 122 and 124 (e.g., intermediate shafts), joints 150 and 152 (e.g., constant velocity (CV) joints), shafts 154 and 156 (e.g., stub shafts), wheel hub systems 158 and 160, and/or drive wheels 126 and 128. Specifically, the differential 112 is rotationally coupled to the shafts 122 and 124. The shafts 122 and 124 are rotationally coupled to the joints 150 and 152, in the illustrated example. Further, in the illustrated example, the joints 150 and 152 are rotationally coupled to the shafts 154 and 156 which are rotationally coupled to the wheel hub systems 158 and 160. However, in other examples, the shafts 122 and 124 may be directly coupled to the wheel hub systems 158 and 160. It will be understood that the drive wheels 126 and 128 may be removably coupled to the wheel hub systems 158 and 160 when the vehicle axle is assembled.
The shafts 122 and 124 may be housed via an axle tube assembly 162. A steering system 164 which may include a steering knuckle, yoke, steering cylinder, and the like may be coupled to the axle tube assembly 162 and the wheel hub systems 158 and 160.
The wheel hub systems 158 and 160 may be coupled to the drive wheels 126 and 128, respectively using multiple types of coupling devices. These devices are discussed in greater detail herein. Using multiple wheel end coupling devices allows the drivetrain's modularity to be increased, thereby enabling the vehicle's applicability to be expanded to a wider variety of vehicle platforms.
The transmission 104 may include gears, shafts, and the like which may function to alter the speed of the mechanical input from the prime mover for speed changes at the transmission output. The transmission 104 may be a multi-speed transmission which includes clutches, a continuously variable transmission, or a single speed transmission in different examples. However, as discussed above, the transmission may be omitted from the drivetrain, in other examples.
The differential 112 may be an open differential, a locking differential, a limited slip differential, and the like. In the example illustrated in
The wheel hub systems 158 and 160 include attachment interfaces that are configured to attach to torque couplings 163 as well as hub lock devices 165. Arrows 166 indicate the different mechanical connections that may be formed between the wheel hub systems 158 and 160 and the torque couplings 163 or the hub lock devices 165. The torque couplings 163 are each configured to continuously transfer mechanical power between the corresponding shaft and drive wheel, during axle operation. Axle operation includes an operating condition where power is transferred to the axle shafts from the upstream powertrain components such as the transmission and the prime mover. Axle operation also includes an operating condition where torque is transferred to the drive wheel from the road such as during towing operation, for instance. The hub lock devices 165 are configured to selectively transfer mechanical power from the shafts 154 and 156 to the drive wheels 126 and 128, respectively. To elaborate, when the hub lock devices 165 are locked the devices continuously transfer mechanical power between the respective shaft and drive wheel. Conversely, when the hub lock devices 165 are unlocked, mechanical power transfer through the hub lock devices 165 is inhibited. the hub lock devices 165 may be actuated via electro-mechanical, hydraulic, or pneumatic actuators 168 (either via operator input or automatically via a controller which is elaborated upon herein). In other examples, the hub lock devices 165 may be manually actuated via manual mechanical actuators 170. Thus, both manually actuated hub lockers and remotely actuated hub lockers may be removably coupled to the wheel hub systems 158 and 160. A detailed example of a wheel hub system is shown in
The vehicle 100 shown in
The controller 191 may receive various signals from sensors 195 coupled to various regions of the vehicle 100. For example, the sensors 195 may include a pedal position sensor designed to detect a depression of an operator-actuated pedal such as an accelerator pedal and/or a brake pedal, speed sensor(s) at the transmission input and/or output shaft, gear selector sensor, clutch position sensors, and the like. An input device 198 (e.g., accelerator pedal, brake pedal, drive mode selector, gear selector, combinations thereof, and the like) may further provide input signals indicative of an operator's intent for vehicle control.
Upon receiving the signals from the various sensors 195 of
An axis system is provided in
An inner bearing 212 is further included in the wheel hub system 200. Specifically, an inner race 214 of the bearing is coupled to the shaft 202 at a location inboard of the exterior splines 208. The inner bearing 212 is a ball bearing in the illustrated example which allows the bearing to manage radial loads. Further, an outer race 216 of the inner bearing 212 is coupled to a hub body 218. An outer bearing assembly 220 is coupled to an outer circumference 222 of the hub body 218. The outer bearing assembly 220 is a thrust bearing assembly designed to manage axial and radial loads in the illustrated example. Thus, the thrust bearing assembly includes tapered rollers 224, an inner race 226 in face sharing contact with the hub body 218, and an outer race 228. The outer race 228 may be coupled to a steering knuckle 230 in a steering system or other suitable axle component. In the illustrated example, the outer bearing assembly 220 is positioned within a recess 232 in the hub body 218 to increase the system's space efficiency, although other hub body contours have been contemplated.
A snap ring 234 is coupled to an interior 235 of the hub body 218. Further, a circlip 236 is coupled to an outer surface 238 of the shaft 202. To expound, the circlip 236 is positioned on an outboard side 240 of the inner bearing 212 and the snap ring 234 is positioned on an inboard side 242 of the inner bearing 212. In this way, the circlip 236 and the snap ring 234 axially delimit the inner bearing 212, allowing the bearing to be retained in a desired axial position.
In the illustrated example, the hub body 218 further includes a flange 244 that is removably attached to a wheel flange 246 via fasteners 248 or other suitable attachment devices. The wheel flange 246 is profiled to attach to a drive wheel via fasteners 250.
The hub body 218 further includes interior splines 252 (e.g., female splines) that circumferentially surround the exterior splines 208 on the shaft 202. Therefore, a diameter 254 of the interior splines 252 is greater than a diameter 256 of the exterior splines 208. A gap 258 is formed between the interior splines 252 and the exterior splines 208. This gap allows for the torque couplings and the hub lock devices (which are expanded upon herein) to be effectively attached to the wheel hub system 200.
The hub body 218 further includes a fastener joint 260 at an outboard side 262. The fastener joint 260 is profiled to receive fasteners which allow the torque couplings and the hub lock devices to be removably attached to the wheel hub system 200. A rotational axis 270 of the wheel hub system 200 is provided in
It will be understood that the wheel hub system 200 may be incorporated into an axle assembly.
Additionally, fasteners 608 extend through openings 610 in the torque coupling 600 and extend into the fastener joint 260 in the hub body 218 to allow the torque coupling 600 to be removably secured to the wheel hub system 200. The torque coupling 600 is therefore positioned in an interior opening 612 of the hub body 218 as well as in an opening 614 of the wheel flange 246.
The hub lock device 900 includes a manual actuator 910 in the illustrated example. The manual actuator 910 allows a vehicle operator to manually lock and unlock the wheel hub system. For instance, the hub lock device may be unlocked for towing or when all wheel drive operation is not desired. Alternatively, the hub lock device may be configured to be hydraulically or pneumatically actuated, for instance.
The invention is further described in the following paragraphs. In one aspect, a wheel hub system is provided that comprises an outer bearing assembly with an inner race coupled to a hub body; a wheel flange configured to removably coupled to the hub body; an inner bearing including an outer race that is coupled to the hub body and an inner race that is coupled to a shaft; wherein the hub body includes interior splines which circumferentially surround exterior splines on the shaft. In one example, the interior splines may be configured to removably couple to: in a first configuration, a hub lock device configured to inhibits mechanical power transfer therethrough when unlocked; and in a second configuration, a torque coupling that during axle operation continuously transfers mechanical power between the shaft and a wheel. Further, in one example, the exterior splines on the shaft may be configured to mate with interior splines in both the hub lock device and the torque coupling in the first configuration and the second configuration, respectively. In one example, the hub body may include a fastener joint that is configured to receive multiple fasteners that extend through the hub lock device in the first configuration, and through the torque coupling in the second configuration. Still further, in one example, the hub lock device may be configured for manual engagement and disengagement. In one example, the hub lock device may be configured for electronic engagement and disengagement. In one example, the wheel hub system may further comprise a circlip removably coupled to the shaft adjacent to an outboard side of the inner bearing. In one example, the wheel hub system may further comprise a snap ring removably coupled to the hub body adjacent to an inboard side of the inner bearing, wherein the circlip and the snap ring axially delimit the inner bearing. In one example, the shaft may be a stub shaft in a steering axle. Still further in one example, the steering axle may be a rigid beam steering axle. In one example, the shaft may be coupled to an electric powertrain. In one example, the inner bearing may be a ball bearing.
In another aspect, a wheel hub system is provided that comprises an outer bearing assembly with an inner race coupled to a hub body; a wheel flange configured to removably coupled to the hub body; an inner bearing including an outer race that is coupled to the hub body and an inner race that is coupled to a shaft which includes male splines; wherein the hub body includes female splines; wherein the female splines have a larger diameter than the male splines; wherein the female splines and the male splines are configured to attach to a hub lock device and a torque coupling in different configurations. Further in one example, the hub body may include a fastener joint that is configured to receive multiple fasteners that extend through the hub lock device in the first configuration, and through the torque coupling in the second configuration. In one example, an inner diameter of the fastener joint may be larger than the diameter of the female splines. In one example, the wheel hub system may further comprise a circlip and a snap ring each which are positioned at opposing sides of the inner bearing and axially capture the inner bearing. In one example, the inner bearing may be a ball bearing and wherein the outer bearing assembly is a thrust bearing assembly. Still further in one example, the shaft may be a stub shaft configured to attach to an axle joint. In one example, the axle joint may be rotationally coupled to an electric powertrain. In one example, the wheel hub system may further comprise a steering knuckle attached to the outer bearing assembly.
While various embodiments have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant arts that the disclosed subject matter may be embodied in other specific forms without departing from the spirit of the subject matter. The embodiments described above are therefore to be considered in all respects as illustrative, not restrictive. As such, the configurations and routines disclosed herein are exemplary in nature, and that these specific examples are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to powertrains that include different types of propulsion sources including different types of electric machines and/or internal combustion engines. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
As used herein, the term “approximately” is construed to mean plus or minus five percent of the range, unless otherwise specified.
The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
The present application claims priority to U.S. Provisional Patent Application No. 63/481,580, entitled “AXLE ASSEMBLY WITH DISCONNECT SYSTEM”, and filed on Jan. 25, 2023. The entire contents of the above-listed application are hereby incorporated by reference for all purposes.
Number | Date | Country | |
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63481580 | Jan 2023 | US |