Vehicle axle assembly

An axle assembly for a vehicle includes a frame, a motor, and a pair of gear reduction subassemblies. The frame extends between a first distal end and a second distal end. The second distal end opposes the first distal end. The motor is secured to the frame between the first distal end and the second distal end. The pair of gear reduction subassemblies are rotatably coupled to the first distal end and the second distal end and configured to drive rotation from the motor to a pair of wheels. Each gear reduction subassembly includes a plurality of gears defining a plurality of gear ratios.

FIELD

The present disclosure relates generally to a vehicle axle assembly, and more particularly to a vehicle axle assembly including a wheel speed reduction assembly.

BACKGROUND

Conventional electric propulsion systems for motor vehicles include an electric motor driving one or more wheels coupled to an axle. The electric motor often includes a single-speed gear reduction. In some examples, the electric motor drives the wheels through a conventional axle and gear reduction assembly to produce an optimal level of torque and speed. In other examples, the electric motor and the gear reduction assembly are incorporated into the axle assembly, from which the electric motor drives the wheels through the gear reduction assembly to produce an optimal level of torque and speed. While known axle assemblies have proven suitable for their intended purposes, there remains a need for improvement in the pertinent art.

SUMMARY

One aspect of the disclosure provides a vehicle axle assembly including a frame, a motor, and a gear reduction subassembly. The frame has a central portion and a distal end spaced from the central portion. The motor has a stator and a rotor. The stator is secured to the frame near the central portion and the rotor is rotatably coupled to the stator. The gear reduction subassembly includes a hub, a first planetary gear set, a second planetary gear set, and a synchromesh gear. The hub is configured to be secured to a wheel. The first planetary gear set has a first gear ratio and is configured to rotate the hub. The second planetary gear set has a second gear ratio different than the first gear ratio and is configured to rotate the hub. The synchromesh gear is coupled to the rotor and is configured to selectively engage the first planetary gear set and the second planetary gear set.

Implementations of the disclosure may include one or more of the following optional features. In some implementations, the vehicle axle assembly includes a hydraulic channel in fluid communication with a cavity disposed between the synchromesh gear and one of the first planetary gear set or the second planetary gear set, the hydraulic channel configured to direct a hydraulic force into the cavity and upon the synchromesh gear. The vehicle axle assembly may include a first spring and a second spring. The first spring may be disposed on a first side of the synchromesh gear and the second spring may be disposed on a second side of the synchromesh gear opposite the first spring. The first and second springs may bias the synchromesh gear toward an unengaged position. The hydraulic force may cause the synchromesh gear to overcome the biasing of the first and second springs to selectively engage one of the first planetary gear set or the second planetary gear set.

The gear reduction subassembly may include a brake rotor rotationally aligned with the hub. The first planetary gear set and the second planetary gear set may be disposed further from the central portion of the frame than the brake rotor.

The first planetary gear set and the second planetary gear set may be disposed further from the central portion of the frame than the hub.

Another aspect of the disclosure provides an axle assembly for a vehicle includes a frame, a motor, and a pair of gear reduction subassemblies. The frame extends between a first distal end and a second distal end. The second distal end opposes the first distal end. The motor is secured to the frame between the first distal end and the second distal end. The pair of gear reduction subassemblies are rotatably coupled to the first distal end and the second distal end and configured to drive rotation from the motor to a pair of wheels. Each gear reduction subassembly includes a plurality of gears defining a plurality of gear ratios. This aspect may include one or more of the following optional features.

In some implementations, the plurality of gears includes a first planetary gear set having a first gear ratio and a second planetary gear set having a second gear ratio different than the first gear ratio.

Each gear reduction subassembly may include a hub configured to be secured to each of the wheels and a brake rotor rotationally aligned with the hub. The hub and the brake rotor may be disposed between the plurality of gears and the motor.

In some implementations, the plurality of gears includes a first planetary gear set having a first gear ratio, a second planetary gear set having a second gear ratio different than the first gear ratio, and a synchromesh gear coupled to the motor, the synchromesh gear configured to selectively engage the first planetary gear set and the second planetary gear set. The axle assembly may include a pair of hydraulic channels in fluid communication with cavities disposed between the synchromesh gear and the first planetary gear set and the second planetary gear set. The hydraulic channels may be configured to direct a hydraulic force into the cavities and upon the synchromesh gear. The gear reduction subassembly may include a pair of springs disposed on either side of the synchromesh gear. The pair of springs may bias the synchromesh gear toward an unengaged position. The hydraulic force may cause the synchromesh gear to overcome the biasing of the pair of springs to selectively engage one of the first planetary gear set or the second planetary gear set.

Another aspect of the disclosure provides a vehicle including a pair of wheels and an axle assembly including a frame, a motor, and a pair of gear reduction subassemblies. The frame extends between opposing distal ends. The motor is secured to the frame between the distal ends. The pair of gear reduction subassemblies are rotatably coupled to the frame and configured to drive rotation from the motor to the pair of wheels. Each gear reduction subassembly includes a plurality of gears defining a plurality of gear ratios. This aspect may include one or more of the following optional features.

In some implementations, the plurality of gears includes a first planetary gear set having a first gear ratio and a second planetary gear set having a second gear ratio different than the first gear ratio.

Each gear reduction subassembly may include a hub configured to be secured to each of the wheels and a brake rotor rotationally aligned with the hub. The hub and the brake rotor may be disposed between the plurality of gears and the motor.

In some implementations, the plurality of gears includes a first planetary gear set having a first gear ratio, a second planetary gear set having a second gear ratio different than the first gear ratio, and a synchromesh gear coupled to the motor, the synchromesh gear configured to selectively engage the first planetary gear set and the second planetary gear set. The axle assembly may include a pair of hydraulic channels in fluid communication with cavities disposed between the synchromesh gear and the first planetary gear set. The hydraulic channels may be configured to direct a hydraulic force into the cavities and upon the synchromesh gear. The gear reduction subassembly may include a pair of springs disposed on either side of the synchromesh gear. The pair of springs may bias the synchromesh gear toward an unengaged position. The hydraulic force may cause the synchromesh gear to overcome the biasing of the pair of springs to selectively engage one of the first planetary gear set or the second planetary gear set.

DETAILED DESCRIPTION

Referring toFIG. 1, a vehicle10is illustrated and includes a body12, an axle assembly14, and a plurality of wheels16. While the vehicle10is generally illustrated as being a commercial utility vehicle, it will be appreciated that the vehicle10may include other types of vehicles (e.g., passenger car, van, truck, etc.) within the scope of the present disclosure. In this regard, the body12may define a passenger compartment18for housing one or more occupants or users of the vehicle10. As will be described in more detail below, the axle assembly14may be coupled to, and drive rotation of, the wheels16for moving the vehicle10in forward and rearward directions relative to the ground.

As illustrated inFIG. 2, the axle assembly14may include a frame20extending between opposed distal ends22and a central portion24disposed between the distal ends22. The axle assembly14may include a motor28secured to the frame20between the distal ends22, (e.g., at or near the central portion24). A pair of gear reduction subassemblies50may be rotatably coupled to the frame20and configured to drive rotation of the wheels16(e.g., a pair of wheels16), via the motor28. As illustrated inFIG. 3, each gear reduction subassembly50may include a plurality of gears including an outer planetary gear set92and an inner planetary gear set114, defining a plurality of gear ratios.

Referring toFIGS. 1 and 2, the frame20includes the distal ends22, the central portion24disposed between the distal ends22, and a cradle26located at or near the central portion24. When installed in the vehicle10, the frame20may extend laterally across the vehicle10from one of the distal ends22at or near one of the wheels16to the other of the distal ends22at or near another of the wheels16. For example, as shown inFIG. 1, the axle assembly14may be associated with front wheels16of the vehicle10, such that the frame20extends between a front-right wheel16and a front-left wheel16. In other implementations, the axle assembly14may be associated with rear wheels16of the vehicle10or with any other suitable wheels16.

The central portion24of the frame20may include the cradle26configured to contain the motor28. In some implementations, the cradle26may include four laterally-extending members27,27a-dhaving attachment means (e.g., welding, mechanical fasteners, etc.), for securing the motor28to the cradle26. The laterally-extending members27may define an opening configured to receive the motor28. For example, the opening may be accessible from a bottom, a top, and/or a side of the frame20, and the motor28may be received in the bottom, the top, or the side of the frame20. In some implementations, the attachment means includes a pair of brackets29configured to properly position and align the motor28with the wheels16. The frame20may define sealed members extending from the central portion24to the distal ends22which are configured to receive a lubricating fluid. The frame20may be formed of any suitable material, including, but not limited to, steel, carbon steel, chrome-molybdenum steel, aluminum, etc.

As illustrated inFIGS. 2 and 3, the motor28may include a stator30and a rotor32. As set forth above, the motor28(i.e., the stator30) may be mounted to the frame20at the cradle26. In other implementations, the motor28may be mounted to a location on the vehicle10other than the frame20such as, for example, the body12. The rotor32may be rotatably coupled to the stator30and may extend from the central portion24past each of the distal ends22. The rotor32may extend along and rotate about an axis A1(FIG. 3). In some implementations, a single motor28may be provided having a single stator30and a single rotor32extending past the distal ends22. In other implementations, a single motor28may be provided having a single stator30and two rotors32each extending past one of the distal ends22. In yet another implementation, two motors28may be provided, each having a single stator30and a single rotor32extending past one of the distal ends22. In some implementations, the motor28may be an electric axle (“e-axle”) including at least one gearbox.

The rotor32may include distal ends34located on opposite sides of the stator30. For example, as shown inFIGS. 4-5B, the distal ends34may extend through a central aperture82of an outer carrier80when the gear reduction subassembly50is assembled (as shown inFIGS. 1, 5A, and 5B). Referring toFIG. 3, the stator30may include rotor teeth36disposed on an outer surface of the stator30. As set forth below, the rotor teeth36may be configured to meshingly engage central teeth140of a synchromesh gear136.

In some implementations, the motor28may be an electric motor, such as, for example, a brushless AC motor, a brushed DC motor, a brushless DC motor, or an AC induction motor. Further, the motor28may be connected to a battery (not shown), such as, for example, a lead-acid battery, a nickel metal hydride battery, a sodium battery, a lithium-ion battery. In other implementations, the motor28may be any suitable motor, including, but not limited to, an internal combustion engine.

Referring toFIG. 2, the axle assembly14may include a brake caliper mount38, a brake rotor40, and a hub42. In some implementations, the axle assembly14may include a pair of brake caliper mounts38, a pair of brake rotors40, and a pair of hubs42, with each one of the pairs being substantially similar to the other one of the pairs. The brake caliper mount38may be configured to receive a brake caliper (not shown) that is engageable with the brake rotor40to provide a braking force for the vehicle10. The brake caliper mount38may be secured to the frame20and the brake rotor40may be secured to the hub42. The hub42may be rotatably coupled to the frame20about the axis A1and may include a first flange44extending around the frame20. The first flange44may include a plurality of wheel bolts46and a plurality of outer casing bolts48. The wheel bolts46may secure a wheel16to the axle assembly14, such that, when the wheel16is secured to the axle assembly14, the hub42may be rotationally aligned with the wheel16. That is, as the wheel rotates16, the hub42similarly rotates and vice versa. As set forth below, the outer casing bolts48may secure an outer casing52to the hub42.

Referring toFIGS. 3-5B, the axle assembly14may include the pair of gear reduction subassemblies50, which may be substantially the same as each other. Accordingly, only one of the pair of gear reduction subassemblies50(e.g., a right gear reduction subassembly50) is described below. The gear reduction assembly50may include the outer casing52, a carrier housing64, the outer carrier80, an inner carrier86, an outer planetary gear set92, an inner planetary gear set114, the synchromesh gear136, an outer spring154, and an inner spring156. In some implementations, the gear reduction subassembly50includes the brake rotor40and the hub42. The components of the gear reduction subassembly50may be formed of the same materials, different materials, or a combination of materials. For example, the components of the gear reduction subassembly50may be formed of steel, aluminum, brass, copper, iron, carbon fiber, plastic, etc.

The outer casing52may include a main body54and a second flange58. The main body54of the outer casing52may be generally cylindrical and the second flange58may extend radially from an end of the main body54. The main body54may include outer casing teeth56located on an interior surface of the main body54. As set forth below, the outer casing teeth56may be configured to meshingly engage carrier housing teeth68of the carrier housing64. The second flange58may include wheel bolt apertures60and outer casing bolt apertures62. The wheel bolt apertures60may be configured to receive the wheel bolts46and the outer casing bolt apertures62may be configured to receive the outer casing bolts48. That is, the second flange58of the outer casing52may be secured to the first flange44of the hub42via the casing bolt apertures62, and the outer casing52may be rotationally aligned with the hub42. Additionally, the outer casing52may be rotationally aligned with the hub42about the axis A1by the wheel bolts46engaging with the wheel bolt apertures60. In other implementations, the outer casing52may be secured to the hub42in any suitable manner, such as, welding, gluing, etc.

Referring toFIGS. 2 and 3, the carrier housing64may include an outer ring66and an inner wall70. The outer ring66may include the carrier housing teeth68disposed on an outer surface of the outer ring66. The carrier housing teeth68may be configured to meshingly engage with the outer casing teeth56such that, as the carrier housing64rotates, the outer casing52similarly rotates and vice versa. The inner wall70of the carrier housing64may include a central stem72, outer depressions76,76a-d, and inner depressions78,78a-d(FIG. 5A). The central stem72may extend from opposite surfaces of the inner wall70and may define a central aperture74extending through the carrier housing64. As will become apparent, the central aperture74may be configured to receive the rotor32of the motor28, an outer sun gear94, an inner sun gear116, the synchromesh gear136, the outer spring154, and the inner spring156.

The outer carrier80may include the central aperture82and a plurality of radial apertures84,84a-d. The outer carrier80may have a generally circular cross-section with a radius equal to, or slightly less than, a radius of the outer ring66of the carrier housing64. The central aperture82of the outer carrier80may be configured to receive the rotor32. Similarly, the inner carrier86may include a central aperture88and a plurality of radial apertures90,90a-d. The inner carrier86may have a generally circular cross-section with a radius equal to, or slightly less than, a radius of the outer ring66of the carrier housing64. The central aperture88of the inner carrier86may be configured to receive the rotor32. The outer carrier80and the inner carrier86may be secured to the carrier housing64in any suitable manner, such as, for example, mechanical engagements, mechanical fasteners, welding, glue, etc.

Referring toFIGS. 3-5B, the outer planetary gear set92may include the outer sun gear94rotatably coupled to the rotor32and a plurality of outer planetary gears104,104a-d. The outer sun gear94may be rotatable about the axis A1. The outer sun gear94may include a central stem96extending from a distal surface of the outer sun gear94and the central stem96may define a central aperture98extending through the outer sun gear94. The central aperture98may be configured to receive the rotor32, and the central stem96may be configured to engage and rotate relative to the central aperture82of the outer carrier80. That is, an inner radius of the central aperture82of the outer carrier80may be slightly larger than an outer radius of the central stem96such that the central stem96may be supported by the central aperture82of the outer carrier80, but still rotate relative to the outer carrier80.

The outer sun gear94may include first outer sun teeth100and second outer sun teeth102. The first outer sun teeth100may be disposed closer to the central portion24of the frame20than the second outer sun teeth102when the gear reduction subassembly50is assembled. The first outer sun teeth100may be disposed on a radial surface of the outer sun gear94that has a larger radius than a radial surface of the outer sun gear94on which the second outer sun teeth102are disposed.

The plurality of outer planetary gears104,104a-dmay each include a stem106,106a-dand outer planet teeth112,112a-d. Each stem106may extend from a proximal end108,108a-dto a distal end110,110a-d. In other implementations, there may be two separate stems106disposed on opposite sides of each of the outer planetary gears104. Each proximal end108may be configured to engage the outer depressions76of the carrier housing64, such that each stem106may be supported by one of the outer depressions76, but may still rotate relative to the inner wall70of the carrier housing64. The outer planet teeth112may be configured to meshingly engage the second outer sun teeth102. The outer planetary gear set92may define a first gear ratio.

The inner planetary gear set114may include the inner sun gear116rotatably coupled to the rotor32and a plurality of inner planetary gears126,126a-d. The inner sun gear116may be rotatable about the axis A1. The inner sun gear116may include a central stem118extending from a distal surface of the inner sun gear116and the central stem118may define a central aperture120extending through the inner sun gear116. The central aperture120may be configured to receive the rotor32and the central stem118may be configured to engage and rotate relative to the central aperture82of the outer carrier80. That is, an inner radius of the central aperture82of the outer carrier80may be slightly larger than an outer radius of the central stem118such that the central stem118may be supported by the central aperture82of the outer carrier80, but may still rotate relative to the outer carrier80.

The inner sun gear116may include first inner sun teeth122and second inner sun teeth124. The second inner sun teeth124may be disposed closer to the central portion24of the frame20than the first inner sun teeth122when the gear reduction subassembly50is assembled. The first inner sun teeth122may be disposed on a radial surface of the inner sun gear116that has a larger radius than a radial surface of the inner sun gear116on which the second inner sun teeth124are disposed.

The plurality of inner planetary gears126,126a-dmay each include a stem128,128a-dand inner planet teeth134,134a-d. Each stem128may extend from a proximal end130,130a-dto a distal end132,132a-d. In other implementations, there may be two separate stems128disposed on opposite sides of each of the inner planetary gears126. Each proximal end130may be configured to engage the inner depressions78of the carrier housing64, such that each stem128may be supported by one of the inner depressions78, but may still rotate relative to the inner wall70of the carrier housing64. The inner planet teeth134may be configured to meshingly engage the second inner sun teeth124. The inner planetary gear set114may define a second gear ratio. The second gear ratio may be different than the first gear ratio. For example, the second gear ratio may be greater than or less than the first gear ratio.

The gear reduction subassembly50, including the outer planetary gear set92and the inner planetary gear set114, may be disposed further from the central portion24of the frame20than the brake rotor40and the hub42. For example, the gear reduction subassembly50may be disposed further from the stator30of the motor28than the brake rotor40and the hub42. For example, the hub42and the brake rotor40may be disposed between the gear reduction subassembly50and the stator30of the motor28. In some implementations, the gear reduction subassembly50may be disposed substantially within wheel wells of the vehicle10. That is, the gear reduction subassembly50may be substantially surrounded by tires of the wheels16. In other implementations, the gear reduction subassembly50may be disposed between the stator30of the motor28and the hub42. In such implementations, the gear reduction subassembly50may be fixed to the frame20and the hub42may drive rotation of the wheels16.

With continued reference toFIGS. 3-5B, the synchromesh gear136may be disposed between the outer sun gear94and the inner sun gear116when the gear reduction subassembly50is assembled. The synchromesh gear136and the outer sun gear94may define an outer cavity146. The synchromesh gear136and the inner sun gear116may define an inner cavity148. The synchromesh gear136may include a central aperture138extending through the synchromesh gear136, the central aperture138configured to receive the rotor32of the motor28. Disposed around an interior surface that defines the central aperture138is the central teeth140that are configured to meshingly engage the rotor teeth36of the rotor32, such that the rotor32may drive rotation of the synchromesh gear136. That is, the synchromesh gear136may be coupled to and rotationally aligned with the rotor32. The synchromesh gear136may be coupled to the rotor32such that the synchromesh gear136is slidable along the axis A1and the rotor32drives rotation of the synchromesh gear136about the axis A1. In other implementations, the synchromesh gear136may be rotationally aligned with the rotor32in any suitable manner, such as, for example, welding, mechanical fasteners, etc.

The synchromesh gear136may include a distal inner circumferential surface having outer synchromesh teeth142and a proximal inner circumferential surface having inner synchromesh teeth144opposite the outer synchromesh teeth142. For example, when the gear reduction subassembly50is assembled, the outer synchromesh teeth142may be disposed further from the central portion24of the frame20than the inner synchromesh teeth144. The synchromesh gear136is configured to selectively engage the outer planetary gear set92and the inner planetary gear set114. For example, the outer synchromesh teeth142may be configured to meshingly engage the first outer sun teeth100of the outer sun gear92, and the inner synchromesh teeth144may be configured to meshingly engage the first inner sun teeth122of the inner sun gear116. The synchromesh gear136may be movable (e.g., translatable relative to the axis A1) between an unengaged position (FIG. 4), an outer position (FIG. 5A), and an inner position (FIG. 5B). In the unengaged position, the synchromesh gear136may be located between and spaced from the outer sun gear92and the inner sun gear116. In the outer position, the outer synchromesh teeth142of the synchromesh gear136may be meshingly-engaged with the first outer sun teeth100of the outer sun gear94and the synchromesh gear136may be spaced from the inner sun gear116. In the inner position, the inner synchromesh teeth144of the synchromesh gear136may be meshingly-engaged with the first inner sun teeth122of the inner sun gear116and the synchromesh gear136may be spaced from the outer sun gear92. In some implementations, the synchromesh gear136may be a dog clutch or any other suitable type of gear.

Referring toFIGS. 5A and 5B, the outer spring154may be disposed in the outer cavity146on a first side of the synchromesh gear136and the inner spring156may be disposed in the inner cavity148on a second side of the synchromesh gear136opposite the first side. For example, the inner spring156may be disposed closer to the central portion24of the frame20than the outer spring154when the gear reduction subassembly50is assembled. The outer spring154and the inner spring156may each abut the synchromesh gear136and may each bias the synchromesh gear136to the unengaged position. For example, the outer spring154may extend from the outer sun gear94to the synchromesh gear136, exerting opposing forces on the outer sun gear94and the synchromesh gear136, and the inner spring156may extend from the inner sun gear116to the synchromesh gear136, exerting opposing forces on the inner sun gear116and the synchromesh gear136. The outer spring154and the inner spring156may be substantially similar to each other, or the outer spring154and the inner spring156may be different from each other. The outer spring154and the inner spring156may each be any suitable type of spring, such as, for example, a helical spring, a conical spring, a Belleville spring, etc.

With continued reference toFIGS. 5A and 5B, the rotor32includes a first hydraulic channel150and a second hydraulic channel152. The first hydraulic channel150may surround and be spaced from the second hydraulic channel152, and the first hydraulic channel150may extend through the rotor32into the outer cavity146(e.g., into the central aperture74of the carrier housing64between the inner sun gear116and the synchromesh gear136). The second hydraulic channel152may extend through a center of the rotor32into the inner cavity148(e.g., into the central aperture74of the carrier housing64between the outer sun gear94and the synchromesh gear136). The first hydraulic channel150and the second hydraulic channel152may each be configured to direct a hydraulic force into the outer cavity146and the inner cavity148, respectively, and upon the synchromesh gear136. Each hydraulic force may be sourced from a hydraulic system (not shown) that may be secured to a portion of the axle assembly14or any suitable location on the vehicle10. The hydraulic force directed by the first hydraulic channel150may cause the synchromesh gear136to overcome the biasing of the outer spring154to move to the outer position where the outer synchromesh teeth142of the synchromesh gear136are meshingly-engaged with the first outer sun teeth100of the outer sun gear94. The hydraulic force directed by the second hydraulic channel152may cause the synchromesh gear136to overcome the biasing of the inner spring156to move to the inner position where the inner synchromesh teeth144of the synchromesh gear136are meshingly-engaged with the first inner sun teeth122of the inner sun gear116.

As one example of operation, the motor28drives rotation of the rotor32about the axis A1which drives rotation of the synchromesh gear136about the axis A1. If the synchromesh gear136is in the unengaged position, then the synchromesh gear136rotates without contacting the outer sun gear94or the inner sun gear116. If a hydraulic force sufficient enough to overcome the biasing of the outer spring154is directed through the first hydraulic channel150, then the synchromesh gear136is moved to the outer position where the outer synchromesh teeth142of the synchromesh gear136are meshingly-engaged with the first outer sun teeth100of the outer sun gear94. Upon the rotor32rotating, the synchromesh gear136in the outer position rotates and drives rotation of the outer sun gear94about the axis A1by the engagement of the outer synchromesth teeth142and the first outer sun teeth100. The outer sun gear94drives rotation of the outer planetary gears104about axes extending through the center of each stem106and around the axis A1by the engagement of the second outer sun teeth102and the outer planet teeth112. As the outer planetary gears104rotate around the axis A1, the outer planetary gears104drive rotation of the outer carrier80about the axis A1by the stems106engaging the radial apertures84. By being secured to the carrier housing64, the outer carrier80drives rotation of the carrier housing64, which, in turn, drives rotation of the outer casing about the axis A1by the engagement of the carrier housing teeth68and the outer casing teeth56. By being secured to the hub42via the wheel bolts46and the outer casing bolts48, the outer casing52drives rotation of the hub42about the axis A1. By being secured to the wheels16via the wheel bolts46, the hub42drives rotation of the wheels16about the axis A1, which causes the vehicle10to move in either forward or rearward directions relative to the ground.

As another example of operation, the motor28drives rotation of the rotor32about the axis A1which drives rotation of the synchromesh gear136about the axis A1. If the synchromesh gear136is in the unengaged position, then the synchromesh gear136rotates without contacting the outer sun gear94or the inner sun gear116. If a hydraulic force sufficient enough to overcome the biasing of the inner spring156is directed through the second hydraulic channel152, then the synchromesh gear136is moved to the inner position where the inner synchromesh teeth144of the synchromesh gear136are meshingly-engaged with the first inner sun teeth122of the inner sun gear116. Upon the rotor32rotating, the synchromesh gear136in the inner position rotates and drives rotation of the inner sun gear116about the axis A1by the engagement of the inner synchromesth teeth144and the first inner sun teeth122. The inner sun gear116drives rotation of the inner planetary gears126about axes extending through the center of each stem128and around the axis A1by the engagement of the second inner sun teeth124and the inner planet teeth134. As the inner planetary gears126rotate around the axis A1, the inner planetary gears126drive rotation of the inner carrier86about the axis A1by the stems128engaging the radial apertures90. By being secured to the carrier housing64, the inner carrier86drives rotation of the carrier housing64, which, in turn, drives rotation of the outer casing about the axis A1by the engagement of the carrier housing teeth68and the outer casing teeth56. By being secured to the hub42via the wheel bolts46and the outer casing bolts48, the outer casing52drives rotation of the hub42about the axis A1. By being secured to the wheels16via the wheel bolts46, the hub42drives rotation of the wheels16about the axis A1, which causes the vehicle10to move in either forward or rearward directions relative to the ground.

As set forth above, the synchromesh gear136may selectively engage one of the outer planetary gear set92and the inner planetary gear set114by a hydraulic force being directed either through the first hydraulic channel150or the second hydraulic channel152, respectively. The selective engagement of the synchromesh gear136determines whether the wheels16are driven via the first gear ratio or the second gear ratio. The gear ratio determines the speed at which the wheels16rotate relative to the speed at which the rotor32rotates. The first gear ratio may be determined by the number of teeth in each of (i) the outer synchromesh teeth142, (ii) the first outer sun teeth100, (iii) the second outer sun teeth102, (iv) the outer planet teeth112, (v) the carrier housing teeth68, and/or (vi) the outer casing teeth56. The second gear ratio may be determined by the number of teeth in each of (i) the inner synchromesh teeth144, (ii) the first inner sun teeth122, (iii) the second inner sun teeth124, (iv) the inner planet teeth134, (v) the carrier housing teeth68, and/or (vi) the outer casing teeth56.

In some implementations, the axle assembly14may incorporate the motor28which may be an e-axle including at least one gearbox. The axle assembly14may be configured for vehicles having independent rear suspension. For example, the axle assembly14may utilize a high volume e-axle traditionally incorporated into passenger vehicles (e.g., light duty trucks) and the gear reduction subassembly50may operate to match the torque and/or speed requirements of a commercial vehicle application (e.g., cargo vans). By using the outer planetary gear set92having the first gear ratio and the inner planetary gear set114having the second gear ratio, the axle assembly14may have the ability to adapt to different e-axles. For example, the axle assembly14may convert torque and/or speed inputs from an e-axle to suitable torque/speed outputs for the desired vehicle application.

Other benefits may include, but are not limited to: lower cost for an electric propulsion system due to leveraging high volume applications for major components (e.g., e-motor, inverter, gear reduction, etc.); axle assembly can be configured to allow for conventional frame spacing and attachment with minimal modifications and minimal space requirements; and axle assembly can be tailored to specific vehicle application for toque/speed allowing broad range of usage of a high volume e-axle.