Patent Description:
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.

<CIT> discloses an electric drive axle assembly for a vehicle including an electric power assembly including a power motor being fixed to the transmission housing, a transmission having a transmission housing, a differential being supported by the transmission housing, an axle case assembly including an axle case component and two half axles.

<CIT> discloses A drive assembly for motor graders which includes a differential gear arrangement and at least one final drive arrangement. The differential gear arrangement includes a differential housing and at least one differential output shaft. The final drive arrangement is driven by differential housing and the differential output shaft.

<CIT> discloses a twin-wheel drive module for driving two vehicle wheels which are disposed axially from one another and rotatable around two axes of rotation aligned with one another.

<CIT> discloses working vehicle drivers with a compact multi-speed change component.

<CIT> discloses a cover plate for a drive assembly that includes a bearing housing having a bearing cavity, a thrust bearing axially disposed within the bearing cavity that includes a cup, cone and plurality of rollers disposed between cup and cone raceways.

<CIT> discloses a drive assembly including a housing cylinder with a cap end, an attachment end with a first attachment surface, and gear teeth disposed around an inner circumference to form at least one ring gear. A planetary gear set may be surrounded by the housing cylinder and includes at least one sun gear and at least one set of planet gears.

This section provides a general summary of the invention and is not a comprehensive invention of its full scope or all of its features.

According to a first aspect of the invention, there is provided 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 invention 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 invention 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 invention 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, 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.

The drawings described herein are for illustrative purposes only.

Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present invention.

Referring to <FIG>, a vehicle <NUM> is illustrated and includes a body <NUM>, an axle assembly <NUM>, and a plurality of wheels <NUM>. While the vehicle <NUM> is generally illustrated as being a commercial utility vehicle, it will be appreciated that the vehicle <NUM> may include other types of vehicles (e.g., passenger car, van, truck, etc.). In this regard, the body <NUM> may define a passenger compartment <NUM> for housing one or more occupants or users of the vehicle <NUM>. As will be described in more detail below, the axle assembly <NUM> may be coupled to, and drive rotation of, the wheels <NUM> for moving the vehicle <NUM> in forward and rearward directions relative to the ground.

As illustrated in <FIG>, the axle assembly <NUM> may include a frame <NUM> extending between opposed distal ends <NUM> and a central portion <NUM> disposed between the distal ends <NUM>. The axle assembly <NUM> may include a motor <NUM> secured to the frame <NUM> between the distal ends <NUM>, (e.g., at or near the central portion <NUM>). A pair of gear reduction subassemblies <NUM> may be rotatably coupled to the frame <NUM> and configured to drive rotation of the wheels <NUM> (e.g., a pair of wheels <NUM>), via the motor <NUM>. As illustrated in <FIG>, each gear reduction subassembly <NUM> may include a plurality of gears including an outer planetary gear set <NUM> and an inner planetary gear set <NUM>, defining a plurality of gear ratios.

Referring to <FIG> and <FIG>, the frame <NUM> includes the distal ends <NUM>, the central portion <NUM> disposed between the distal ends <NUM>, and a cradle <NUM> located at or near the central portion <NUM>. When installed in the vehicle <NUM>, the frame <NUM> may extend laterally across the vehicle <NUM> from one of the distal ends <NUM> at or near one of the wheels <NUM> to the other of the distal ends <NUM> at or near another of the wheels <NUM>. For example, as shown in <FIG>, the axle assembly <NUM> may be associated with front wheels <NUM> of the vehicle <NUM>, such that the frame <NUM> extends between a front-right wheel <NUM> and a front-left wheel <NUM>. In other implementations, the axle assembly <NUM> may be associated with rear wheels <NUM> of the vehicle <NUM> or with any other suitable wheels <NUM>.

The central portion <NUM> of the frame <NUM> may include the cradle <NUM> configured to contain the motor <NUM>. In some implementations, the cradle <NUM> may include four laterally-extending members <NUM>, 27a-d having attachment means (e.g., welding, mechanical fasteners, etc.), for securing the motor <NUM> to the cradle <NUM>. The laterally-extending members <NUM> may define an opening configured to receive the motor <NUM>. For example, the opening may be accessible from a bottom, a top, and/or a side of the frame <NUM>, and the motor <NUM> may be received in the bottom, the top, or the side of the frame <NUM>. In some implementations, the attachment means includes a pair of brackets <NUM> configured to properly position and align the motor <NUM> with the wheels <NUM>. The frame <NUM> may define sealed members extending from the central portion <NUM> to the distal ends <NUM> which are configured to receive a lubricating fluid. The frame <NUM> may be formed of any suitable material, including, but not limited to, steel, carbon steel, chrome-molybdenum steel, aluminum, etc..

As illustrated in <FIG> and <FIG>, the motor <NUM> may include a stator <NUM> and a rotor <NUM>. As set forth above, the motor <NUM> (i.e., the stator <NUM>) may be mounted to the frame <NUM> at the cradle <NUM>. In other implementations, the motor <NUM> may be mounted to a location on the vehicle <NUM> other than the frame <NUM> such as, for example, the body <NUM>. The rotor <NUM> may be rotatably coupled to the stator <NUM> and may extend from the central portion <NUM> past each of the distal ends <NUM>. The rotor <NUM> may extend along and rotate about an axis A<NUM> (<FIG>). In some implementations, a single motor <NUM> may be provided having a single stator <NUM> and a single rotor <NUM> extending past the distal ends <NUM>. In other implementations, a single motor <NUM> may be provided having a single stator <NUM> and two rotors <NUM> each extending past one of the distal ends <NUM>. In yet another implementation, two motors <NUM> may be provided, each having a single stator <NUM> and a single rotor <NUM> extending past one of the distal ends <NUM>. In some implementations, the motor <NUM> may be an electric axle ("e-axle") including at least one gearbox.

The rotor <NUM> may include distal ends <NUM> located on opposite sides of the stator <NUM>. For example, as shown in <FIG>, the distal ends <NUM> may extend through a central aperture <NUM> of an outer carrier <NUM> when the gear reduction subassembly <NUM> is assembled (as shown in <FIG>, <FIG>, and <FIG>). Referring to <FIG>, the stator <NUM> may include rotor teeth <NUM> disposed on an outer surface of the stator <NUM>. As set forth below, the rotor teeth <NUM> may be configured to meshingly engage central teeth <NUM> of a synchromesh gear <NUM>.

In some implementations, the motor <NUM> may 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 motor <NUM> may 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 motor <NUM> may be any suitable motor, including, but not limited to, an internal combustion engine.

Referring to <FIG>, the axle assembly <NUM> may include a brake caliper mount <NUM>, a brake rotor <NUM>, and a hub <NUM>. In some implementations, the axle assembly <NUM> may include a pair of brake caliper mounts <NUM>, a pair of brake rotors <NUM>, and a pair of hubs <NUM>, with each one of the pairs being substantially similar to the other one of the pairs. The brake caliper mount <NUM> may be configured to receive a brake caliper (not shown) that is engageable with the brake rotor <NUM> to provide a braking force for the vehicle <NUM>. The brake caliper mount <NUM> may be secured to the frame <NUM> and the brake rotor <NUM> may be secured to the hub <NUM>. The hub <NUM> may be rotatably coupled to the frame <NUM> about the axis A<NUM> and may include a first flange <NUM> extending around the frame <NUM>. The first flange <NUM> may include a plurality of wheel bolts <NUM> and a plurality of outer casing bolts <NUM>. The wheel bolts <NUM> may secure a wheel <NUM> to the axle assembly <NUM>, such that, when the wheel <NUM> is secured to the axle assembly <NUM>, the hub <NUM> may be rotationally aligned with the wheel <NUM>. That is, as the wheel rotates <NUM>, the hub <NUM> similarly rotates and vice versa. As set forth below, the outer casing bolts <NUM> may secure an outer casing <NUM> to the hub <NUM>.

Referring to <FIG>, the axle assembly <NUM> may include the pair of gear reduction subassemblies <NUM>, which may be substantially the same as each other. Accordingly, only one of the pair of gear reduction subassemblies <NUM> (e.g., a right gear reduction subassembly <NUM>) is described below. The gear reduction assembly <NUM> may include the outer casing <NUM>, a carrier housing <NUM>, the outer carrier <NUM>, an inner carrier <NUM>, an outer planetary gear set <NUM>, an inner planetary gear set <NUM>, the synchromesh gear <NUM>, an outer spring <NUM>, and an inner spring <NUM>. In some implementations, the gear reduction subassembly <NUM> includes the brake rotor <NUM> and the hub <NUM>. The components of the gear reduction subassembly <NUM> may be formed of the same materials, different materials, or a combination of materials. For example, the components of the gear reduction subassembly <NUM> may be formed of steel, aluminum, brass, copper, iron, carbon fiber, plastic, etc..

The outer casing <NUM> may include a main body <NUM> and a second flange <NUM>. The main body <NUM> of the outer casing <NUM> may be generally cylindrical and the second flange <NUM> may extend radially from an end of the main body <NUM>. The main body <NUM> may include outer casing teeth <NUM> located on an interior surface of the main body <NUM>. As set forth below, the outer casing teeth <NUM> may be configured to meshingly engage carrier housing teeth <NUM> of the carrier housing <NUM>. The second flange <NUM> may include wheel bolt apertures <NUM> and outer casing bolt apertures <NUM>. The wheel bolt apertures <NUM> may be configured to receive the wheel bolts <NUM> and the outer casing bolt apertures <NUM> may be configured to receive the outer casing bolts <NUM>. That is, the second flange <NUM> of the outer casing <NUM> may be secured to the first flange <NUM> of the hub <NUM> via the casing bolt apertures <NUM>, and the outer casing <NUM> may be rotationally aligned with the hub <NUM>. Additionally, the outer casing <NUM> may be rotationally aligned with the hub <NUM> about the axis A<NUM> by the wheel bolts <NUM> engaging with the wheel bolt apertures <NUM>. In other implementations, the outer casing <NUM> may be secured to the hub <NUM> in any suitable manner, such as, welding, gluing, etc..

Referring to <FIG> and <FIG>, the carrier housing <NUM> may include an outer ring <NUM> and an inner wall <NUM>. The outer ring <NUM> may include the carrier housing teeth <NUM> disposed on an outer surface of the outer ring <NUM>. The carrier housing teeth <NUM> may be configured to meshingly engage with the outer casing teeth <NUM> such that, as the carrier housing <NUM> rotates, the outer casing <NUM> similarly rotates and vice versa. The inner wall <NUM> of the carrier housing <NUM> may include a central stem <NUM>, outer depressions <NUM>, 76a-d, and inner depressions <NUM>, 78a-d (<FIG>). The central stem <NUM> may extend from opposite surfaces of the inner wall <NUM> and may define a central aperture <NUM> extending through the carrier housing <NUM>. As will become apparent, the central aperture <NUM> may be configured to receive the rotor <NUM> of the motor <NUM>, an outer sun gear <NUM>, an inner sun gear <NUM>, the synchromesh gear <NUM>, the outer spring <NUM>, and the inner spring <NUM>.

The outer carrier <NUM> may include the central aperture <NUM> and a plurality of radial apertures <NUM>, 84a-d. The outer carrier <NUM> may have a generally circular cross-section with a radius equal to, or slightly less than, a radius of the outer ring <NUM> of the carrier housing <NUM>. The central aperture <NUM> of the outer carrier <NUM> may be configured to receive the rotor <NUM>. Similarly, the inner carrier <NUM> may include a central aperture <NUM> and a plurality of radial apertures <NUM>, 90a-d. The inner carrier <NUM> may have a generally circular cross-section with a radius equal to, or slightly less than, a radius of the outer ring <NUM> of the carrier housing <NUM>. The central aperture <NUM> of the inner carrier <NUM> may be configured to receive the rotor <NUM>. The outer carrier <NUM> and the inner carrier <NUM> may be secured to the carrier housing <NUM> in any suitable manner, such as, for example, mechanical engagements, mechanical fasteners, welding, glue, etc..

Referring to <FIG>, the outer planetary gear set <NUM> may include the outer sun gear <NUM> rotatably coupled to the rotor <NUM> and a plurality of outer planetary gears <NUM>, 104a-d. The outer sun gear <NUM> may be rotatable about the axis A<NUM>. The outer sun gear <NUM> may include a central stem <NUM> extending from a distal surface of the outer sun gear <NUM> and the central stem <NUM> may define a central aperture <NUM> extending through the outer sun gear <NUM>. The central aperture <NUM> may be configured to receive the rotor <NUM>, and the central stem <NUM> may be configured to engage and rotate relative to the central aperture <NUM> of the outer carrier <NUM>. That is, an inner radius of the central aperture <NUM> of the outer carrier <NUM> may be slightly larger than an outer radius of the central stem <NUM> such that the central stem <NUM> may be supported by the central aperture <NUM> of the outer carrier <NUM>, but still rotate relative to the outer carrier <NUM>.

The outer sun gear <NUM> may include first outer sun teeth <NUM> and second outer sun teeth <NUM>. The first outer sun teeth <NUM> may be disposed closer to the central portion <NUM> of the frame <NUM> than the second outer sun teeth <NUM> when the gear reduction subassembly <NUM> is assembled. The first outer sun teeth <NUM> may be disposed on a radial surface of the outer sun gear <NUM> that has a larger radius than a radial surface of the outer sun gear <NUM> on which the second outer sun teeth <NUM> are disposed.

The plurality of outer planetary gears <NUM>, 104a-d may each include a stem <NUM>, 106a-d and outer planet teeth <NUM>, 112a-d. Each stem <NUM> may extend from a proximal end <NUM>, 108a-d to a distal end <NUM>, 110a-d. In other implementations, there may be two separate stems <NUM> disposed on opposite sides of each of the outer planetary gears <NUM>. Each proximal end <NUM> may be configured to engage the outer depressions <NUM> of the carrier housing <NUM>, such that each stem <NUM> may be supported by one of the outer depressions <NUM>, but may still rotate relative to the inner wall <NUM> of the carrier housing <NUM>. The outer planet teeth <NUM> may be configured to meshingly engage the second outer sun teeth <NUM>. The outer planetary gear set <NUM> may define a first gear ratio.

The inner planetary gear set <NUM> may include the inner sun gear <NUM> rotatably coupled to the rotor <NUM> and a plurality of inner planetary gears <NUM>, 126a-d. The inner sun gear <NUM> may be rotatable about the axis A<NUM>. The inner sun gear <NUM> may include a central stem <NUM> extending from a distal surface of the inner sun gear <NUM> and the central stem <NUM> may define a central aperture <NUM> extending through the inner sun gear <NUM>. The central aperture <NUM> may be configured to receive the rotor <NUM> and the central stem <NUM> may be configured to engage and rotate relative to the central aperture <NUM> of the outer carrier <NUM>. That is, an inner radius of the central aperture <NUM> of the outer carrier <NUM> may be slightly larger than an outer radius of the central stem <NUM> such that the central stem <NUM> may be supported by the central aperture <NUM> of the outer carrier <NUM>, but may still rotate relative to the outer carrier <NUM>.

The inner sun gear <NUM> may include first inner sun teeth <NUM> and second inner sun teeth <NUM>. The second inner sun teeth <NUM> may be disposed closer to the central portion <NUM> of the frame <NUM> than the first inner sun teeth <NUM> when the gear reduction subassembly <NUM> is assembled. The first inner sun teeth <NUM> may be disposed on a radial surface of the inner sun gear <NUM> that has a larger radius than a radial surface of the inner sun gear <NUM> on which the second inner sun teeth <NUM> are disposed.

The plurality of inner planetary gears <NUM>, 126a-d may each include a stem <NUM>, 128a-d and inner planet teeth <NUM>, 134a-d. Each stem <NUM> may extend from a proximal end <NUM>, 130a-d to a distal end <NUM>, 132a-d. In other implementations, there may be two separate stems <NUM> disposed on opposite sides of each of the inner planetary gears <NUM>. Each proximal end <NUM> may be configured to engage the inner depressions <NUM> of the carrier housing <NUM>, such that each stem <NUM> may be supported by one of the inner depressions <NUM>, but may still rotate relative to the inner wall <NUM> of the carrier housing <NUM>. The inner planet teeth <NUM> may be configured to meshingly engage the second inner sun teeth <NUM>. The inner planetary gear set <NUM> may 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 subassembly <NUM>, including the outer planetary gear set <NUM> and the inner planetary gear set <NUM>, may be disposed further from the central portion <NUM> of the frame <NUM> than the brake rotor <NUM> and the hub <NUM>. For example, the gear reduction subassembly <NUM> may be disposed further from the stator <NUM> of the motor <NUM> than the brake rotor <NUM> and the hub <NUM>. For example, the hub <NUM> and the brake rotor <NUM> may be disposed between the gear reduction subassembly <NUM> and the stator <NUM> of the motor <NUM>. In some implementations, the gear reduction subassembly <NUM> may be disposed substantially within wheel wells of the vehicle <NUM>. That is, the gear reduction subassembly <NUM> may be substantially surrounded by tires of the wheels <NUM>. In other implementations, the gear reduction subassembly <NUM> may be disposed between the stator <NUM> of the motor <NUM> and the hub <NUM>. In such implementations, the gear reduction subassembly <NUM> may be fixed to the frame <NUM> and the hub <NUM> may drive rotation of the wheels <NUM>.

With continued reference to <FIG>, the synchromesh gear <NUM> may be disposed between the outer sun gear <NUM> and the inner sun gear <NUM> when the gear reduction subassembly <NUM> is assembled. The synchromesh gear <NUM> and the outer sun gear <NUM> may define an outer cavity <NUM>. The synchromesh gear <NUM> and the inner sun gear <NUM> may define an inner cavity <NUM>. The synchromesh gear <NUM> may include a central aperture <NUM> extending through the synchromesh gear <NUM>, the central aperture <NUM> configured to receive the rotor <NUM> of the motor <NUM>. Disposed around an interior surface that defines the central aperture <NUM> is the central teeth <NUM> that are configured to meshingly engage the rotor teeth <NUM> of the rotor <NUM>, such that the rotor <NUM> may drive rotation of the synchromesh gear <NUM>. That is, the synchromesh gear <NUM> may be coupled to and rotationally aligned with the rotor <NUM>. The synchromesh gear <NUM> may be coupled to the rotor <NUM> such that the synchromesh gear <NUM> is slidable along the axis A<NUM> and the rotor <NUM> drives rotation of the synchromesh gear <NUM> about the axis A<NUM>. In other implementations, the synchromesh gear <NUM> may be rotationally aligned with the rotor <NUM> in any suitable manner, such as, for example, welding, mechanical fasteners, etc..

The synchromesh gear <NUM> may include a distal inner circumferential surface having outer synchromesh teeth <NUM> and a proximal inner circumferential surface having inner synchromesh teeth <NUM> opposite the outer synchromesh teeth <NUM>. For example, when the gear reduction subassembly <NUM> is assembled, the outer synchromesh teeth <NUM> may be disposed further from the central portion <NUM> of the frame <NUM> than the inner synchromesh teeth <NUM>. The synchromesh gear <NUM> is configured to selectively engage the outer planetary gear set <NUM> and the inner planetary gear set <NUM>. For example, the outer synchromesh teeth <NUM> may be configured to meshingly engage the first outer sun teeth <NUM> of the outer sun gear <NUM>, and the inner synchromesh teeth <NUM> may be configured to meshingly engage the first inner sun teeth <NUM> of the inner sun gear <NUM>. The synchromesh gear <NUM> may be movable (e.g., translatable relative to the axis A<NUM>) between an unengaged position (<FIG>), an outer position (<FIG>), and an inner position (<FIG>). In the unengaged position, the synchromesh gear <NUM> may be located between and spaced from the outer sun gear <NUM> and the inner sun gear <NUM>. In the outer position, the outer synchromesh teeth <NUM> of the synchromesh gear <NUM> may be meshingly-engaged with the first outer sun teeth <NUM> of the outer sun gear <NUM> and the synchromesh gear <NUM> may be spaced from the inner sun gear <NUM>. In the inner position, the inner synchromesh teeth <NUM> of the synchromesh gear <NUM> may be meshingly-engaged with the first inner sun teeth <NUM> of the inner sun gear <NUM> and the synchromesh gear <NUM> may be spaced from the outer sun gear <NUM>. In some implementations, the synchromesh gear <NUM> may be a dog clutch or any other suitable type of gear.

Referring to <FIG> and <FIG>, the outer spring <NUM> may be disposed in the outer cavity <NUM> on a first side of the synchromesh gear <NUM> and the inner spring <NUM> may be disposed in the inner cavity <NUM> on a second side of the synchromesh gear <NUM> opposite the first side. For example, the inner spring <NUM> may be disposed closer to the central portion <NUM> of the frame <NUM> than the outer spring <NUM> when the gear reduction subassembly <NUM> is assembled. The outer spring <NUM> and the inner spring <NUM> may each abut the synchromesh gear <NUM> and may each bias the synchromesh gear <NUM> to the unengaged position. For example, the outer spring <NUM> may extend from the outer sun gear <NUM> to the synchromesh gear <NUM>, exerting opposing forces on the outer sun gear <NUM> and the synchromesh gear <NUM>, and the inner spring <NUM> may extend from the inner sun gear <NUM> to the synchromesh gear <NUM>, exerting opposing forces on the inner sun gear <NUM> and the synchromesh gear <NUM>. The outer spring <NUM> and the inner spring <NUM> may be substantially similar to each other, or the outer spring <NUM> and the inner spring <NUM> may be different from each other. The outer spring <NUM> and the inner spring <NUM> may each be any suitable type of spring, such as, for example, a helical spring, a conical spring, a Belleville spring, etc..

With continued reference to <FIG> and <FIG>, the rotor <NUM> includes a first hydraulic channel <NUM> and a second hydraulic channel <NUM>. The first hydraulic channel <NUM> may surround and be spaced from the second hydraulic channel <NUM>, and the first hydraulic channel <NUM> may extend through the rotor <NUM> into the outer cavity <NUM> (e.g., into the central aperture <NUM> of the carrier housing <NUM> between the inner sun gear <NUM> and the synchromesh gear <NUM>). The second hydraulic channel <NUM> may extend through a center of the rotor <NUM> into the inner cavity <NUM> (e.g., into the central aperture <NUM> of the carrier housing <NUM> between the outer sun gear <NUM> and the synchromesh gear <NUM>). The first hydraulic channel <NUM> and the second hydraulic channel <NUM> may each be configured to direct a hydraulic force into the outer cavity <NUM> and the inner cavity <NUM>, respectively, and upon the synchromesh gear <NUM>. Each hydraulic force may be sourced from a hydraulic system (not shown) that may be secured to a portion of the axle assembly <NUM> or any suitable location on the vehicle <NUM>. The hydraulic force directed by the first hydraulic channel <NUM> may cause the synchromesh gear <NUM> to overcome the biasing of the outer spring <NUM> to move to the outer position where the outer synchromesh teeth <NUM> of the synchromesh gear <NUM> are meshingly-engaged with the first outer sun teeth <NUM> of the outer sun gear <NUM>. The hydraulic force directed by the second hydraulic channel <NUM> may cause the synchromesh gear <NUM> to overcome the biasing of the inner spring <NUM> to move to the inner position where the inner synchromesh teeth <NUM> of the synchromesh gear <NUM> are meshingly-engaged with the first inner sun teeth <NUM> of the inner sun gear <NUM>.

As one example of operation, the motor <NUM> drives rotation of the rotor <NUM> about the axis A<NUM> which drives rotation of the synchromesh gear <NUM> about the axis A<NUM>. If the synchromesh gear <NUM> is in the unengaged position, then the synchromesh gear <NUM> rotates without contacting the outer sun gear <NUM> or the inner sun gear <NUM>. If a hydraulic force sufficient enough to overcome the biasing of the outer spring <NUM> is directed through the first hydraulic channel <NUM>, then the synchromesh gear <NUM> is moved to the outer position where the outer synchromesh teeth <NUM> of the synchromesh gear <NUM> are meshingly-engaged with the first outer sun teeth <NUM> of the outer sun gear <NUM>. Upon the rotor <NUM> rotating, the synchromesh gear <NUM> in the outer position rotates and drives rotation of the outer sun gear <NUM> about the axis A<NUM> by the engagement of the outer synchromesth teeth <NUM> and the first outer sun teeth <NUM>. The outer sun gear <NUM> drives rotation of the outer planetary gears <NUM> about axes extending through the center of each stem <NUM> and around the axis A<NUM> by the engagement of the second outer sun teeth <NUM> and the outer planet teeth <NUM>. As the outer planetary gears <NUM> rotate around the axis A<NUM>, the outer planetary gears <NUM> drive rotation of the outer carrier <NUM> about the axis A<NUM> by the stems <NUM> engaging the radial apertures <NUM>. By being secured to the carrier housing <NUM>, the outer carrier <NUM> drives rotation of the carrier housing <NUM>, which, in turn, drives rotation of the outer casing about the axis A<NUM> by the engagement of the carrier housing teeth <NUM> and the outer casing teeth <NUM>. By being secured to the hub <NUM> via the wheel bolts <NUM> and the outer casing bolts <NUM>, the outer casing <NUM> drives rotation of the hub <NUM> about the axis A<NUM>. By being secured to the wheels <NUM> via the wheel bolts <NUM>, the hub <NUM> drives rotation of the wheels <NUM> about the axis A<NUM>, which causes the vehicle <NUM> to move in either forward or rearward directions relative to the ground.

As another example of operation, the motor <NUM> drives rotation of the rotor <NUM> about the axis A<NUM> which drives rotation of the synchromesh gear <NUM> about the axis A<NUM>. If the synchromesh gear <NUM> is in the unengaged position, then the synchromesh gear <NUM> rotates without contacting the outer sun gear <NUM> or the inner sun gear <NUM>. If a hydraulic force sufficient enough to overcome the biasing of the inner spring <NUM> is directed through the second hydraulic channel <NUM>, then the synchromesh gear <NUM> is moved to the inner position where the inner synchromesh teeth <NUM> of the synchromesh gear <NUM> are meshingly-engaged with the first inner sun teeth <NUM> of the inner sun gear <NUM>. Upon the rotor <NUM> rotating, the synchromesh gear <NUM> in the inner position rotates and drives rotation of the inner sun gear <NUM> about the axis A<NUM> by the engagement of the inner synchromesth teeth <NUM> and the first inner sun teeth <NUM>. The inner sun gear <NUM> drives rotation of the inner planetary gears <NUM> about axes extending through the center of each stem <NUM> and around the axis A<NUM> by the engagement of the second inner sun teeth <NUM> and the inner planet teeth <NUM>. As the inner planetary gears <NUM> rotate around the axis A<NUM>, the inner planetary gears <NUM> drive rotation of the inner carrier <NUM> about the axis A<NUM> by the stems <NUM> engaging the radial apertures <NUM>. By being secured to the carrier housing <NUM>, the inner carrier <NUM> drives rotation of the carrier housing <NUM>, which, in turn, drives rotation of the outer casing about the axis A<NUM> by the engagement of the carrier housing teeth <NUM> and the outer casing teeth <NUM>. By being secured to the hub <NUM> via the wheel bolts <NUM> and the outer casing bolts <NUM>, the outer casing <NUM> drives rotation of the hub <NUM> about the axis A<NUM>. By being secured to the wheels <NUM> via the wheel bolts <NUM>, the hub <NUM> drives rotation of the wheels <NUM> about the axis A<NUM>, which causes the vehicle <NUM> to move in either forward or rearward directions relative to the ground.

As set forth above, the synchromesh gear <NUM> may selectively engage one of the outer planetary gear set <NUM> and the inner planetary gear set <NUM> by a hydraulic force being directed either through the first hydraulic channel <NUM> or the second hydraulic channel <NUM>, respectively. The selective engagement of the synchromesh gear <NUM> determines whether the wheels <NUM> are driven via the first gear ratio or the second gear ratio. The gear ratio determines the speed at which the wheels <NUM> rotate relative to the speed at which the rotor <NUM> rotates. The first gear ratio may be determined by the number of teeth in each of (i) the outer synchromesh teeth <NUM>, (ii) the first outer sun teeth <NUM>, (iii) the second outer sun teeth <NUM>, (iv) the outer planet teeth <NUM>, (v) the carrier housing teeth <NUM>, and/or (vi) the outer casing teeth <NUM>. The second gear ratio may be determined by the number of teeth in each of (i) the inner synchromesh teeth <NUM>, (ii) the first inner sun teeth <NUM>, (iii) the second inner sun teeth <NUM>, (iv) the inner planet teeth <NUM>, (v) the carrier housing teeth <NUM>, and/or (vi) the outer casing teeth <NUM>.

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

Claim 1:
A vehicle axle assembly (<NUM>) comprising:
a frame (<NUM>) having a central portion (<NUM>) and a distal end (<NUM>) spaced from the central portion;
a motor (<NUM>) having a stator (<NUM>) and a rotor (<NUM>), the stator (<NUM>) secured to the frame (<NUM>) near the central portion (<NUM>), the rotor (<NUM>) rotatably coupled to the stator (<NUM>); and
a gear reduction subassembly (<NUM>) rotatably coupled to the distal end, the gear reduction subassembly (<NUM>) including:
a hub (<NUM>) configured to be secured to a wheel;
a first planetary gear set (<NUM>) having a first gear ratio and configured to rotate the hub;
characterized in that the gear reduction subassembly (<NUM>) further includes:
a second planetary gear set (<NUM>) having a second gear ratio different than the first gear ratio and configured to rotate the hub (<NUM>); and
a synchromesh gear (<NUM>) coupled to the rotor (<NUM>) and configured to selectively engage the first planetary gear set (<NUM>) and the second planetary gear set (<NUM>).