Patent Description:
An axle assembly having an electric motor module is disclosed in <CIT>.

In at least one embodiment an axle assembly is provided as set out in claim <NUM>.

In at least one embodiment, an axle assembly is provided as set out in claim <NUM>,.

The axle assembly <NUM> may provide torque to one or more traction wheel assemblies that may include a tire mounted on a wheel. The wheel may be mounted to a wheel hub that may be rotatable about a wheel axis.

One or more axle assemblies may be provided with the vehicle. As is best shown with reference to <FIG> and <FIG>, the axle assembly <NUM> includes an electric motor module <NUM>, and a gear reduction module <NUM>. The axle assembly <NUM> may also include a housing assembly <NUM>, a differential assembly <NUM>, and at least one axle shaft <NUM>. As is best shown in <FIG>, the axle assembly <NUM> may include a shift mechanism <NUM>.

The axle housing <NUM> may receive and may support the axle shafts <NUM>. In at least one configuration, the axle housing <NUM> may include a center portion <NUM> and at least one arm portion <NUM>.

The center portion <NUM> may be disposed proximate the center of the axle housing <NUM>. The center portion <NUM> may define a cavity that may at least partially receive the differential assembly <NUM>. As is best shown in <FIG>, a lower region of the center portion <NUM> may at least partially define a sump portion <NUM> that may contain or collect lubricant <NUM>. Lubricant <NUM> in the sump portion <NUM> may be splashed by a ring gear of the differential assembly <NUM> and distributed to lubricate various components.

Referring to <FIG>, the center portion <NUM> may include a carrier mounting surface <NUM>. The carrier mounting surface <NUM> may facilitate mounting of the differential carrier <NUM> to the axle housing <NUM>. For example, the carrier mounting surface <NUM> may face toward and may engage the differential carrier <NUM> and may have a set of holes that may be aligned with corresponding holes on the differential carrier <NUM>. Each hole may receive a fastener, such as a bolt or stud, that may couple the differential carrier <NUM> to the axle housing <NUM>.

Referring to <FIG>, one or more arm portions <NUM> may extend from the center portion <NUM>. For example, two arm portions <NUM> may extend in opposite directions from the center portion <NUM> and away from the differential assembly <NUM>. The arm portions <NUM> may have substantially similar configurations. For example, the arm portions <NUM> may each have a hollow configuration or tubular configuration that may extend around and may receive a corresponding axle shaft <NUM> and may help separate or isolate the axle shaft <NUM> or a portion thereof from the surrounding environment. An arm portion <NUM> or a portion thereof may or may not be integrally formed with the center portion <NUM>. It is also contemplated that the arm portions <NUM> may be omitted.

Referring to <FIG> and <FIG>, the differential carrier <NUM> may be mounted to the center portion <NUM> of the axle housing <NUM>. The differential carrier <NUM> may support the differential assembly <NUM> and may facilitate mounting of the electric motor module <NUM>. For example, the differential carrier may include one or more bearing supports that may support a bearing like a roller bearing assembly that may rotatably support the differential assembly <NUM>. The differential carrier <NUM> may also include a mounting flange <NUM> and a bearing support wall <NUM>.

Referring to <FIG>, the mounting flange <NUM> may facilitate mounting of the electric motor module <NUM>. As an example, the mounting flange <NUM> may be configured as a ring that may extend outward and away from an axis <NUM> and may extend around the axis <NUM>. In at least one configuration, the mounting flange <NUM> may include a set of fastener holes that may be configured to receive fasteners that may secure the electric motor module <NUM> to the mounting flange <NUM>.

The bearing support wall <NUM> may support bearings that may rotatably support other components of the axle assembly <NUM>. For example, the bearing support wall <NUM> may support bearings that may rotatably support a drive pinion <NUM>, bearings that may rotatably support a rotor of the electric motor module <NUM>, or both. The bearing support wall <NUM> may extend in an axial direction away from the axle housing <NUM> and may extend around the axis <NUM>. The bearing support wall <NUM> may define a hole that may extend along or around the axis <NUM> and receive the drive pinion <NUM> and the bearings that rotatably support the drive pinion <NUM>. The bearing support wall <NUM> may be integrally formed with the differential carrier <NUM> or may be a separate component that is secured or fastened to the differential carrier <NUM>.

Referring to <FIG>, the differential assembly <NUM> may be at least partially received in the center portion <NUM> of the housing assembly <NUM>. The differential assembly <NUM> may be rotatable about a differential axis <NUM> and may transmit torque to the axle shafts <NUM> and wheels. The differential assembly <NUM> may be operatively connected to the axle shafts <NUM> and may permit the axle shafts <NUM> to rotate at different rotational speeds in a manner known by those skilled in the art. The differential assembly <NUM> may have a ring gear <NUM> that may have teeth that mate or mesh with the teeth of a gear portion of the drive pinion <NUM>. Accordingly, the differential assembly <NUM> may receive torque from the drive pinion <NUM> via the ring gear <NUM> and transmit torque to the axle shafts <NUM>.

The drive pinion <NUM> may provide torque to the ring gear <NUM>. In an axle assembly that includes a gear reduction module <NUM>, the drive pinion <NUM> may operatively connect the gear reduction module <NUM> to the differential assembly <NUM>. In at least one configuration, the drive pinion <NUM> is rotatable about the axis <NUM> and may be rotatably supported inside another component, such as the bearing support wall <NUM>.

Referring to <FIG>, the axle shafts <NUM> may transmit torque from the differential assembly <NUM> to corresponding wheel hubs and wheels. Two axle shafts <NUM> may be provided such that each axle shaft <NUM> extends through a different arm portion <NUM> of axle housing <NUM>. The axle shafts <NUM> may extend along and may be rotatable about an axis, such as the differential axis <NUM>. Each axle shaft <NUM> may have a first end and a second end. The first end may be operatively connected to the differential assembly <NUM>. The second end may be disposed opposite the first end and may be operatively connected to a wheel. Optionally, gear reduction may be provided between an axle shaft <NUM> and a wheel.

Referring to <FIG>, the electric motor module <NUM>, which may also be referred to as an electric motor, may be mounted to the differential carrier <NUM> and may be operatively connectable to the differential assembly <NUM>. For instance, the electric motor module <NUM> may provide torque to the differential assembly <NUM> via the drive pinion <NUM> and a gear reduction module as will be discussed in more detail below. The electric motor module <NUM> may be primarily disposed outside the differential carrier <NUM>. In addition, the electric motor module <NUM> may be axially positioned between the axle housing <NUM> and the gear reduction module <NUM>. In at least one configuration, the electric motor module <NUM> may include a motor housing <NUM>, a coolant jacket <NUM>, a stator <NUM>, a rotor <NUM>, at least one rotor bearing assembly <NUM>, and a cover <NUM>.

The motor housing <NUM> may extend between the differential carrier <NUM> and the cover <NUM>. The motor housing <NUM> may be mounted to the differential carrier <NUM> and the cover <NUM>. For example, the motor housing <NUM> may extend from the mounting flange <NUM> of the differential carrier <NUM> to the cover <NUM>. The motor housing <NUM> may extend around the axis <NUM> and may define a motor housing cavity <NUM>. The motor housing cavity <NUM> may be disposed inside the motor housing <NUM> and may have a generally cylindrical configuration. The bearing support wall <NUM> of the differential carrier <NUM> may be located inside the motor housing cavity <NUM>. Moreover, the motor housing <NUM> may extend continuously around and may be spaced apart from the bearing support wall <NUM>. In at least one configuration, the motor housing <NUM> may have an exterior side <NUM>, an interior side <NUM>, a first end surface <NUM>, a second end surface <NUM>, and one or more ports <NUM>.

The exterior side <NUM> may face away from the axis <NUM> and may define an exterior or outside surface of the motor housing <NUM>.

The interior side <NUM> may be disposed opposite the exterior side <NUM>. The interior side <NUM> may be disposed at a substantially constant radial distance from the axis <NUM> in one or more configurations.

The first end surface <NUM> may extend between the exterior side <NUM> and the interior side <NUM>. The first end surface <NUM> may be disposed at an end of the motor housing <NUM> that may face toward the differential carrier <NUM>. For instance, the first end surface <NUM> may be disposed adjacent to the mounting flange <NUM> of the differential carrier <NUM>. The motor housing <NUM> and the first end surface <NUM> may or may not be received inside the mounting flange <NUM>.

The second end surface <NUM> may be disposed opposite the first end surface <NUM>. As such, the second end surface <NUM> may be disposed at an end of the motor housing <NUM> that may face toward and may engage the cover <NUM>. The second end surface <NUM> may extend between the exterior side <NUM> and the interior side <NUM> and may or may not be received inside the cover <NUM>.

One or more ports <NUM> may extend through the motor housing <NUM>. The ports <NUM> may be configured as through holes that may extend from the exterior side <NUM> to the interior side <NUM>. The ports <NUM> may allow coolant, such as a fluid like water, a water / antifreeze mixture, or the like, to flow to and from the coolant jacket <NUM> as will be described in more detail below.

Referring to <FIG>, the coolant jacket <NUM> may help cool or remove heat from the stator <NUM>. The coolant jacket <NUM> may be received in the motor housing cavity <NUM> of the motor housing <NUM> and may engage the interior side <NUM> of the motor housing <NUM>. The coolant jacket <NUM> may extend axially between the differential carrier <NUM> and the cover <NUM>. For example, the coolant jacket <NUM> may extend axially from the differential carrier <NUM> to the cover <NUM>. In addition, the coolant jacket <NUM> may extend around the axis <NUM> and the stator <NUM>. As such, the stator <NUM> may be at least partially received in and may be encircled by the coolant jacket <NUM>. Moreover, the coolant jacket <NUM> may extend in a radial direction from the stator <NUM> to the interior side <NUM> of the motor housing <NUM>. In at least one configuration, the coolant jacket <NUM> may include a plurality of channels <NUM>.

The channels <NUM> may extend around the axis <NUM> and may be disposed opposite the stator <NUM>. The channels <NUM> may be configured with an open side that may face away from the axis <NUM> and toward the interior side <NUM> of the motor housing <NUM>. Coolant may be provided to the coolant jacket <NUM> via a first port <NUM> and may exit the coolant jacket <NUM> via a second port <NUM>. For instance, coolant may flow from the first port <NUM> into the channels <NUM>, receive heat from the stator <NUM> as the coolant flows through the channels <NUM>, and exit at the second port <NUM>. One or more baffles may be provided with the coolant jacket <NUM> that may reverse or change the direction of coolant flow to help route coolant from the first port <NUM> to the second port <NUM>.

The stator <NUM> may be received in the motor housing <NUM>. For instance, the stator <NUM> may be received in the motor housing cavity <NUM>. The stator <NUM> may be fixedly positioned with respect to the coolant jacket <NUM>. For example, the stator <NUM> may extend around the axis <NUM> and may include stator windings that may be received inside and may be fixedly positioned with respect to the coolant jacket <NUM>.

The rotor <NUM> may extend around and is rotatable about the axis <NUM>. The rotor <NUM> may be received inside the stator <NUM>, the coolant jacket <NUM>, and the motor housing cavity <NUM> of the motor housing <NUM>. The rotor <NUM> may be rotatable about the axis <NUM> with respect to the differential carrier <NUM> and the stator <NUM>. In addition, the rotor <NUM> may be spaced apart from the stator <NUM> but may be disposed in close proximity to the stator <NUM>. The rotor <NUM> may include magnets or ferromagnetic material that may facilitate the generation of electrical current or may be induction-based. The rotor <NUM> may extend around and may be supported by the bearing support wall <NUM>.

One or more rotor bearing assemblies <NUM> may rotatably support the rotor <NUM>. For example, a rotor bearing assembly <NUM> may receive the bearing support wall <NUM> of the differential carrier <NUM> and may be received inside of the rotor <NUM>. The rotor <NUM> may be operatively connected to the drive pinion <NUM>. For instance, a coupling such as a rotor output flange <NUM> may operatively connect the rotor <NUM> to the gear reduction module <NUM>, which in turn may be operatively connectable with the drive pinion <NUM>.

Referring to <FIG>, the cover <NUM> may be mounted to the motor housing <NUM> and may be disposed opposite the axle housing <NUM> and the differential carrier <NUM>. For example, the cover <NUM> may be mounted to an end or end surface of the motor housing <NUM>, such as the second end surface <NUM>, that may be disposed opposite the differential carrier <NUM>. As such, the cover <NUM> may be spaced apart from and may not engage the differential carrier <NUM>. The cover <NUM> may be provided in various configurations. In at least one configuration, the cover <NUM> may include a first side <NUM> and a second side <NUM>. The first side <NUM> may face toward and may engage the motor housing <NUM>. The second side <NUM> may be disposed opposite the first side <NUM>. The second side <NUM> may face away from the motor housing <NUM> and may be disposed opposite the motor housing <NUM>. The cover <NUM> may also include or define a motor cover opening that may be a through hole through which the drive pinion <NUM> may extend.

Referring to <FIG>, an example of a gear reduction module <NUM> is shown. The gear reduction module <NUM> may transmit torque between the electric motor module <NUM> and the differential assembly <NUM>. As such, the gear reduction module <NUM> may operatively connect the electric motor module <NUM> and the differential assembly <NUM>.

The gear reduction module <NUM> may be disposed outside of the differential carrier <NUM> and may be primarily disposed outside of the electric motor module <NUM> or entirely disposed outside the electric motor module <NUM>, thereby providing a modular construction that may be mounted to the electric motor module <NUM> when gear reduction is desired. For instance, the gear reduction module <NUM> may include a gear reduction module housing <NUM> that may receive gears of the gear reduction module <NUM>. The gear reduction module housing <NUM> may be provided in various configurations. For instance, the gear reduction module housing <NUM> may be a separate component that is mounted to the cover <NUM> or may be integrally formed with the cover <NUM>. The gear reduction module housing <NUM> may extend from the second side <NUM> of the cover <NUM> in a direction that extends away from the electric motor module <NUM>. A gear reduction module cover <NUM> may be disposed on the gear reduction module housing <NUM> and may be removable to provide access to components located inside the gear reduction module housing <NUM>.

The gear reduction module may be provided in various configurations and may include multiple gear sets that are operatively connected to each other. These gear sets may be configured as epicyclic gear sets in which one or more planet gears may revolve or rotate about a central sun gear. Each planet gear may be rotatable about a corresponding axis that may be positioned at a constant or substantially constant radial distance from the axis about which the central sun gear rotates. A particular gear set may or may not have a planetary ring gear that extends around and meshes with the planet gears. For clarity, each gear set is designated with a different name in the discussion below.

Four main configurations of gear reduction modules <NUM>, <NUM>', <NUM>", <NUM>‴ are described below and are best shown in <FIG>. It is to be understood that each gear reduction module configuration can be provided with an axle assembly as described above (i.e., with an axle assembly having a housing assembly <NUM>, differential assembly <NUM>, at least one axle shaft <NUM>, electric motor module <NUM>, shift mechanism <NUM>, drive pinion <NUM>, and a gear reduction module housing <NUM>. Accordingly, magnified views are shown in <FIG> to better depict each gear reduction module configuration rather than the remainder of the axle assembly. Each magnified view is a section view along the axis <NUM>. In these figures, torque transmission paths between the electric motor module <NUM> and drive pinion <NUM> are represented by double-dash lines that are thickened, straight, and not numbered. Torque transmission paths may be bidirectional.

Referring to <FIG> and <FIG>, a first configuration of a gear reduction module <NUM> is shown. The gear reduction module <NUM> includes a first gear set <NUM> and a second gear set <NUM>.

The first gear set <NUM> may be axially positioned along the axis <NUM> between the electric motor module <NUM> and the second gear set <NUM>. The first gear set <NUM> may be configured as a planetary gear set. For instance, the first gear set <NUM> includes a first sun gear <NUM>, a first set of planet gears <NUM>, a first planetary ring gear <NUM>, and a first planet gear carrier <NUM>.

The first sun gear <NUM> may be operatively connected to the rotor <NUM>. For instance, the first sun gear <NUM> may be operatively connected to the rotor <NUM> via the rotor output flange <NUM>. As such, the first sun gear <NUM> may be rotatable about the axis <NUM> with the rotor <NUM> and the rotor output flange <NUM>. Optionally, the first sun gear <NUM> may extend around and may receive the drive pinion <NUM>.

The first set of planet gears <NUM> may be rotatably disposed between the first sun gear <NUM> and the first planetary ring gear <NUM>. Each first planet gear <NUM> may have teeth that mesh with teeth of the first sun gear <NUM> that may extend away from the axis <NUM> and teeth of the first planetary ring gear <NUM> that may extend toward the axis <NUM>. In addition, each first planet gear <NUM> may be rotatable about a corresponding planet gear axis <NUM>.

The first planetary ring gear <NUM> may extend around the axis <NUM> and may receive the first set of planet gears <NUM>. The first planetary ring gear <NUM> isfixedly positioned such that the first planetary ring gear <NUM> is not rotatable about the axis <NUM>. For instance, the first planetary ring gear <NUM> may be received inside and may be fixedly coupled to the gear reduction module housing <NUM> such that the first planetary ring gear <NUM> may not be rotatable about the axis <NUM>.

The first planet gear carrier <NUM> rotatably support the first set of planet gears <NUM>. In addition, the first planet gear carrier <NUM> may be rotatable about the axis <NUM>. The first planet gear carrier <NUM> may extend toward and may be operatively connected to the second gear set <NUM>. In at least one configuration, the first planet gear carrier <NUM> may include a support portion <NUM>, a flange portion <NUM>, and a gear portion <NUM>.

The support portion <NUM> may rotatably support the first set of planet gears <NUM>. The support portion <NUM> may have any suitable configuration. For instance, the support portion <NUM> may include a plurality of pins that may extend along each planet gear axis <NUM> and that may be received inside a hole in each first planet gear <NUM>. A bearing such as a roller bearing assembly may be received inside the hole in each first planet gear <NUM> and may extend around each pin to help rotatably support each first planet gear <NUM>.

The flange portion <NUM> may extend from an end of the support portion <NUM> toward the axis <NUM>. The flange portion <NUM> may be axially positioned along the axis <NUM> between the gear reduction module cover <NUM> and the gears of the second gear set <NUM>.

The gear portion <NUM> may extend from the flange portion <NUM> toward the axis <NUM>. The gear portion <NUM> may include a plurality of teeth that may be arranged around the axis <NUM> in a repeating pattern. The teeth of the gear portion <NUM> may extend toward the axis <NUM> and may be arranged substantially parallel to the axis <NUM>. The gear portion <NUM> may be selectively engaged by a shift collar <NUM> as will be discussed in more detail below.

A support bearing assembly <NUM> may rotatably support the first planet gear carrier <NUM>. The support bearing assembly <NUM> may extend from the gear reduction module housing <NUM> to the first planet gear carrier <NUM>. For instance, the support bearing assembly <NUM> may be received inside the gear reduction module housing <NUM> and the first planet gear carrier <NUM> may be received inside the support bearing assembly <NUM>. The support bearing assembly <NUM> may be disposed proximate the flange portion <NUM> of the first planet gear carrier <NUM> and may be axially positioned between the second gear set <NUM> and the gear reduction module cover <NUM>. As such, the second gear set <NUM> may be axially positioned along the axis <NUM> between the first gear set <NUM> and the support bearing assembly <NUM>.

The second gear set <NUM> may be operatively connected to the first gear set <NUM>. Notwithstanding the first planet gear carrier <NUM>, the second gear set <NUM> may be spaced apart from the first gear set <NUM>. The second gear set <NUM> includes a second sun gear <NUM> and a second set of planet gears <NUM>. A planetary ring gear may be omitted from the second gear set <NUM> in one or more configurations.

The second sun gear <NUM> is rotatable about the axis <NUM>. The second sun gear <NUM> may extend around and may receive the shift collar <NUM>. In addition, the second sun gear <NUM> may include a set of internal teeth <NUM>. The set of internal teeth <NUM> may be disposed inside a hole that is defined by the second sun gear <NUM> and may extend toward the axis <NUM>. The set of internal teeth <NUM> may include a plurality of teeth that may be arranged around the axis <NUM> in a repeating pattern. The internal teeth <NUM> may extend toward the axis <NUM> and may be arranged substantially parallel to the axis <NUM>. The set of internal teeth <NUM> may be selectively engaged by a shift collar <NUM> as will be discussed in more detail below.

The second set of planet gears <NUM> may be rotatably disposed on the second sun gear <NUM>. Each second planet gear <NUM> may have teeth that mesh with teeth of the second sun gear <NUM> that may extend away from the axis <NUM>. Each second planet gear <NUM> may be rotatable about a corresponding planet gear axis, which may be disposed parallel to planet gear axis <NUM>. In at least one configuration, members of the second set of planet gears <NUM> have a smaller diameter than members of the first set of planet gears <NUM>. The support portion <NUM> may rotatably support members of the first and second sets of planet gears <NUM>, <NUM>, and thus planet gears may be rotationally fixed such that a first planet gear <NUM> and a corresponding second planet gear <NUM> may be rotatable about the same planet gear axis <NUM>. For instance, each first planet gear <NUM> may be coupled to a corresponding second planet gear <NUM> to form compound planet gears in which the first planet gear <NUM> and the second planet gear <NUM> rotate together rather than with respect to each other. The second set of planet gears <NUM> are rotatably supported on the first planet gear carrier <NUM>. Each second planet gear <NUM> may be axially positioned between the first gear set <NUM> or a member of the first set of planet gears <NUM> and the flange portion <NUM> of the first planet gear carrier <NUM>. Teeth of the second set of planet gears <NUM> may only mesh with teeth of the second sun gear <NUM> when a planetary ring gear is not provided with the second gear set <NUM>.

Referring to <FIG>, the shift mechanism <NUM> may cooperate with the gear reduction module <NUM> to provide a desired gear reduction ratio to change the torque transmitted between the electric motor module <NUM> and the differential assembly <NUM>, and hence to or from the axle shafts <NUM> of the axle assembly <NUM>. The shift mechanism <NUM> may have any suitable configuration. For instance, the shift mechanism <NUM> may include an actuator <NUM>, which is best shown in <FIG>, and a shift collar <NUM>.

Referring to <FIG>, the actuator <NUM> may be configured to move the shift collar <NUM> along the axis <NUM> to selectively couple a gear set of the gear reduction module <NUM> to the drive pinion <NUM> or decouple a gear set from the drive pinion <NUM>. The actuator <NUM> may be of any suitable type and may be coupled to the shift collar <NUM> in any suitable manner, such as with a linkage like a shift fork.

Referring to <FIG>, the shift collar <NUM> is movable along the axis <NUM> to selectively couple a gear set to the drive pinion <NUM>. For instance, the shift collar <NUM> may be disposed on the drive pinion <NUM> such that the shift collar <NUM> is rotatable about the axis <NUM> with the drive pinion <NUM> and may be movable in an axial direction or along the axis <NUM> with respect to the drive pinion <NUM>. The shift collar <NUM> may be received inside the first sun gear <NUM> and the second sun gear <NUM>. The shift collar <NUM> may include teeth <NUM> that may extend away from the axis <NUM> that may be selectively engageable with corresponding teeth of the gear portion <NUM> of the first planet gear carrier <NUM> or the internal teeth <NUM> of the second sun gear <NUM> to facilitate the transmission of torque between the electric motor module <NUM> and the differential assembly <NUM> at a desired torque ratio. Although a single set of teeth <NUM> is shown, it is contemplated that multiple sets of teeth <NUM> may be provided on the shift collar <NUM> for selectively engaging a gear set.

The shift collar <NUM> may be moveable along the axis <NUM> between a first position and a second position.

Referring to <FIG>, the shift collar <NUM> is shown in the first position. The shift collar <NUM> may couple the first planet gear carrier <NUM> to the drive pinion <NUM> when in the first position, thereby providing a first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the teeth of the gear portion <NUM> of the first planet gear carrier <NUM> when in the first position. Torque may be transmitted from the rotor <NUM> to the first sun gear <NUM> such as via the rotor output flange <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, and then from the first planet gear carrier <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the first position. The shift collar <NUM> may not couple the first sun gear <NUM> or the second sun gear <NUM> to the drive pinion <NUM> when in the first position. As such, the first sun gear <NUM> and the second sun gear <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the first position.

Referring to <FIG>, the shift collar <NUM> is shown in the second position. The shift collar <NUM> may couple the second sun gear <NUM> to the drive pinion <NUM> when in the second position, thereby providing a second drive gear ratio that may differ from the first drive gear ratio. As a nonlimiting example, the first gear ratio may be approximately <NUM> while the second gear ratio may be approximately <NUM>. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the internal teeth <NUM> of the second sun gear <NUM> when in the second position. Torque may be transmitted from the rotor <NUM> to the first sun gear <NUM> such as via the rotor output flange <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, from the first planet gear carrier <NUM> to the second sun gear <NUM> via the second set of planet gears <NUM>, and then from the second sun gear <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the second position. The shift collar <NUM> may not couple the first sun gear <NUM> or the first planet gear carrier <NUM> to the drive pinion <NUM> when in the second position. As such, the first sun gear <NUM> and the first planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the second position.

Referring to <FIG>, a second configuration of a gear reduction module <NUM>' is shown. In this configuration, the gear reduction module <NUM>' may include a first gear set <NUM>, a second gear set <NUM>, and an epicyclic gear set <NUM>. The epicyclic gear set <NUM> may be axially positioned along the axis <NUM> between the electric motor module <NUM> and the first gear set <NUM>. The first gear set <NUM> may be axially positioned along the axis <NUM> between the epicyclic gear set <NUM> and the second gear set <NUM>.

The first gear set <NUM> and the second gear set <NUM> may be the same as that described above, notwithstanding with the following items.

First, the first sun gear <NUM> may be coupled to the epicyclic gear set <NUM> rather than operatively connected to the rotor <NUM> via the rotor output flange <NUM>.

Second, the first sun gear <NUM> may be provided with a set of internal teeth <NUM> that may be selectively engaged by the shift collar <NUM>. The set of internal teeth <NUM> may include a plurality of teeth that may be arranged around the axis <NUM> in a repeating pattern. The internal teeth <NUM> may extend toward the axis <NUM> and may be arranged substantially parallel to the axis <NUM>.

The epicyclic gear set <NUM> may be axially positioned along the axis <NUM> between the electric motor module <NUM> and the first gear set <NUM>. The epicyclic gear set <NUM> may be configured as a planetary gear set. For instance, the epicyclic gear set <NUM> may include an epicyclic sun gear <NUM>, a set of epicyclic planet gears <NUM>, an epicyclic planetary ring gear <NUM>, and an epicyclic planet gear carrier <NUM>.

The epicyclic sun gear <NUM> may be operatively connected to the rotor <NUM>. For instance, the epicyclic sun gear <NUM> may be operatively connected to the rotor <NUM> such as via the rotor output flange <NUM>. As such, the epicyclic sun gear <NUM> may be rotatable about the axis <NUM> with the rotor <NUM> and the rotor output flange <NUM>. The epicyclic sun gear <NUM> may extend around and may receive the drive pinion <NUM>, the shift collar <NUM>, or both.

The set of epicyclic planet gears <NUM> may be rotatably disposed between the epicyclic sun gear <NUM> and the epicyclic planetary ring gear <NUM>. Each epicyclic planet gear <NUM> may have teeth that may mesh with teeth of the epicyclic sun gear <NUM> that may extend away from the axis <NUM> and teeth of the epicyclic planetary ring gear <NUM> that may extend toward the axis <NUM>. Each epicyclic planet gear <NUM> may be rotatable about a corresponding planet gear axis <NUM> or may be rotatable about a planet gear axis that is offset from the planet gear axis <NUM>. In at least one configuration, members of the set of epicyclic planet gears <NUM> may have a smaller diameter than members of the first set of planet gears <NUM>, a larger diameter than members of the second set of planet gears <NUM>, or both.

The epicyclic planetary ring gear <NUM> may extend around the axis <NUM> and may receive the set of epicyclic planet gears <NUM>. The epicyclic planetary ring gear <NUM> may be rotatable about the axis <NUM>. For instance, the epicyclic planetary ring gear <NUM> may be received inside and may be rotatable about the axis <NUM> with respect to the gear reduction module housing <NUM>. The epicyclic planetary ring gear <NUM> may be rotatably supported by an epicyclic support bearing assembly <NUM>. The epicyclic support bearing assembly <NUM> may be received inside and may extend from the gear reduction module housing <NUM> to the epicyclic planetary ring gear <NUM>. The epicyclic planetary ring gear <NUM> may be fixedly positioned with respect to the first sun gear <NUM> such that the first sun gear <NUM> and the epicyclic planetary ring gear <NUM> may be rotatable together about the axis <NUM> and may not rotate with respect to each other. The first sun gear <NUM> and the epicyclic planetary ring gear <NUM> may be integrally formed as a common component or may be an assembly of separate components. In the configuration shown, the epicyclic planetary ring gear <NUM> is connected to the first sun gear <NUM> by a connection portion <NUM>. The connection portion <NUM> may be axially positioned between the epicyclic gear set <NUM> and the first gear set <NUM> and may extend from an end of the epicyclic planetary ring gear <NUM> to an end of the first sun gear <NUM>.

The epicyclic planet gear carrier <NUM> may rotatably support the set of epicyclic planet gears <NUM>. In addition, the epicyclic planet gear carrier <NUM> may be fixedly positioned such that the epicyclic planet gear carrier <NUM> may not be rotatable about the axis <NUM>. For instance, the epicyclic planet gear carrier <NUM> may be fixedly positioned with respect to the gear reduction module housing <NUM> and the cover <NUM> of the electric motor module <NUM>. The epicyclic planet gear carrier <NUM> may extend from the cover <NUM>, the gear reduction module housing <NUM>, or both. In at least one configuration, the epicyclic planet gear carrier <NUM> may include a support portion <NUM>.

The support portion <NUM> may rotatably support the set of epicyclic planet gears <NUM>. The support portion <NUM> may have any suitable configuration. For instance, the support portion <NUM> may include a plurality of pins that may be received inside a hole in each epicyclic planet gear <NUM>. A roller bearing assembly may be received inside the hole in each epicyclic planet gear <NUM> and may extend around each pin to help rotatably support each epicyclic planet gear <NUM>. Each pin may extend along a corresponding planet gear axis, which may or may not be planet gear axis <NUM>.

The shift collar <NUM> may be moveable along the axis <NUM> between a first position, a second position, and a third position.

Referring to <FIG>, the shift collar <NUM> is shown in the first position. The shift collar <NUM> may couple the first planet gear carrier <NUM> to the drive pinion <NUM> when in the first position, thereby providing a first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the teeth of the gear portion <NUM> of the first planet gear carrier <NUM> when in the first position. Torque may be transmitted from the rotor <NUM> to the epicyclic sun gear <NUM> such as via the rotor output flange <NUM>, from the epicyclic sun gear <NUM> to the epicyclic planetary ring gear <NUM> and the first sun gear <NUM> via the set of epicyclic planet gears <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, and then from the first planet gear carrier <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the first position. The shift collar <NUM> may not couple the first sun gear <NUM>, the second sun gear <NUM>, or the epicyclic sun gear <NUM> to the drive pinion <NUM> when in the first position. As such, the first sun gear <NUM>, the second sun gear <NUM>, and the epicyclic sun gear <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the first position.

Referring to <FIG>, the shift collar <NUM> is shown in the second position. The shift collar <NUM> may couple the second sun gear <NUM> to the drive pinion <NUM> when in the second position, thereby providing a second drive gear ratio that may differ from the first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the internal teeth <NUM> of the second sun gear <NUM> when in the second position. Torque may be transmitted from the rotor <NUM> to the epicyclic sun gear <NUM> such as via the rotor output flange <NUM>, from the epicyclic sun gear <NUM> to the epicyclic planetary ring gear <NUM> and the first sun gear <NUM> via the set of epicyclic planet gears <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, from the first planet gear carrier <NUM> to the second sun gear <NUM> via the second set of planet gears <NUM>, and then from the second sun gear <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the second position. The shift collar <NUM> may not couple the first sun gear <NUM>, the epicyclic sun gear <NUM>, or the first planet gear carrier <NUM> to the drive pinion <NUM> when in the second position. As such, the first sun gear <NUM>, epicyclic sun gear <NUM>, and the first planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the second position.

Referring to <FIG>, the shift collar <NUM> is shown in the third position. The shift collar <NUM> may couple the first sun gear <NUM> to the drive pinion <NUM> when in the third position, thereby providing a third drive gear ratio that may differ from the first drive gear ratio and the second drive gear ratio. As a nonlimiting example, the drive gear ratios may be approximately <NUM>, <NUM>, and <NUM>, respectively. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the internal teeth <NUM> of the first sun gear <NUM> when in the third position. Torque may be transmitted from the rotor <NUM> to the epicyclic sun gear <NUM> such as via the rotor output flange <NUM>, from the epicyclic sun gear <NUM> to the epicyclic planetary ring gear <NUM> and the first sun gear <NUM> via the set of epicyclic planet gears <NUM>, and then from the first sun gear <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the third position. The shift collar <NUM> may not couple the epicyclic sun gear <NUM>, the second sun gear <NUM>, or the first planet gear carrier <NUM> to the drive pinion <NUM> when in the third position. As such, the epicyclic sun gear <NUM>, the second sun gear <NUM>, and the first planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the third position.

Referring to <FIG>, a third configuration of a gear reduction module <NUM>" is shown. In this configuration, the gear reduction module <NUM>" may include a first gear set <NUM>, a second gear set <NUM>, and an epicyclic gear set <NUM>. As in the previous configuration, the first gear set <NUM> may be axially positioned between the epicyclic gear set <NUM> and the second gear set <NUM> while the epicyclic gear set <NUM> may be axially positioned between the electric motor module <NUM> and the first gear set <NUM>.

As an overview, the configuration in <FIG> is similar to the configuration in <FIG>, but the first sun gear <NUM> is connected to the epicyclic planet gear carrier <NUM> rather than to the epicyclic planetary ring gear <NUM>. For instance, the epicyclic gear set <NUM> may be the same as that described above with respect to <FIG> except for the following items.

First, the epicyclic sun gear <NUM> may be fixedly positioned such that the epicyclic sun gear <NUM> is not rotatable about the axis <NUM>. For example, the epicyclic sun gear <NUM> may be fixedly coupled to the bearing support wall <NUM> of the differential carrier <NUM>. In the configuration shown, the epicyclic sun gear <NUM> extends along the axis <NUM> into the electric motor module <NUM> and is coupled to the bearing support wall <NUM> proximate the distal end of the bearing support wall <NUM> that is located opposite the axle housing <NUM>. In at least one configuration, the epicyclic sun gear <NUM> may be received inside the bearing support wall <NUM> and may be coupled to the bearing support wall <NUM> inside the bearing support wall <NUM>.

Second, the epicyclic planetary ring gear <NUM> may be operatively connected to the rotor <NUM> or provided with the rotor <NUM>, and thus may be rotatable with the rotor <NUM> about the axis <NUM>. For example, the rotor <NUM> may be provided with a greater axial length and may receive or incorporate the epicyclic planetary ring gear <NUM>. Alternatively, the rotor output flange <NUM> may be provided with a larger diameter than in the previous configurations and may extend from the rotor <NUM> and receive or incorporate the epicyclic planetary ring gear <NUM>. In either configuration, the epicyclic planetary ring gear <NUM> may be considered to be received inside the rotor <NUM>.

Third, the epicyclic planet gear carrier <NUM> may be rotatable about the axis <NUM>. Moreover, the epicyclic planet gear carrier <NUM> and the first sun gear <NUM> may be fixedly positioned with respect to each other such that the first sun gear <NUM> does not rotate with respect to the epicyclic planet gear carrier <NUM>.

Fourth, the epicyclic support bearing assembly <NUM> may be omitted.

It is also noted that the set of epicyclic planet gears <NUM> may have a smaller diameter than members of the first set of planet gears <NUM> and a larger diameter than members of the second set of planet gears <NUM> in one or more configurations.

Referring to <FIG>, the shift collar <NUM> is shown in the first position. The shift collar <NUM> may couple the first planet gear carrier <NUM> to the drive pinion <NUM> when in the first position, thereby providing a first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the teeth of the gear portion <NUM> of the first planet gear carrier <NUM> when in the first position. Torque may be transmitted from the rotor <NUM> and epicyclic planetary ring gear <NUM> to the epicyclic planet gear carrier <NUM> and the first sun gear <NUM> via the set of epicyclic planet gears <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, and then from the first planet gear carrier <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the first position. The shift collar <NUM> may not couple the first sun gear <NUM>, the second sun gear <NUM>, or the epicyclic sun gear <NUM> to the drive pinion <NUM> when in the first position. As such, the first sun gear <NUM> and the second sun gear <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the first position.

Referring to <FIG>, the shift collar <NUM> is shown in the second position. The shift collar <NUM> may couple the second sun gear <NUM> to the drive pinion <NUM> when in the second position, thereby providing a second drive gear ratio that may differ from the first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the internal teeth <NUM> of the second sun gear <NUM> when in the second position. Torque may be transmitted from the rotor <NUM> and epicyclic planetary ring gear <NUM> to the epicyclic planet gear carrier <NUM> and the first sun gear <NUM> via the set of epicyclic planet gears <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, from the first planet gear carrier <NUM> to the second sun gear <NUM> via the second set of planet gears <NUM>, and then from the second sun gear <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the second position. The shift collar <NUM> may not couple the first sun gear <NUM>, the epicyclic sun gear <NUM>, or the first planet gear carrier <NUM> to the drive pinion <NUM> when in the second position. As such, the first sun gear <NUM>, epicyclic sun gear <NUM>, and the first planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the second position.

Referring to <FIG>, the shift collar <NUM> is shown in the third position. The shift collar <NUM> may couple the first sun gear <NUM> to the drive pinion <NUM> when in the third position, thereby providing a third drive gear ratio that may differ from the first drive gear ratio and the second drive gear ratio. As a nonlimiting example, the drive gear ratios may be approximately <NUM>, <NUM>, and <NUM>, respectively. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the internal teeth <NUM> of the first sun gear <NUM> when in the third position. Torque may be transmitted from the rotor <NUM> and epicyclic planetary ring gear <NUM> to the epicyclic planet gear carrier <NUM> and the first sun gear <NUM> via the set of epicyclic planet gears <NUM>, and then from the first sun gear <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the third position. The shift collar <NUM> may not couple the epicyclic sun gear <NUM>, the second sun gear <NUM>, or the first planet gear carrier <NUM> to the drive pinion <NUM> when in the third position. As such, the epicyclic sun gear <NUM>, the second sun gear <NUM>, and the first planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the third position.

Referring to <FIG>, a fourth configuration of a gear reduction module <NUM>‴ is shown. In this configuration, the gear reduction module <NUM>‴ may include a first gear set <NUM>, a second gear set <NUM>, and an epicyclic gear set <NUM>. This configuration is similar to the configuration shown in <FIG> and <FIG> but attaches the epicyclic gear set <NUM> to the second gear set <NUM>. For instance, the first gear set <NUM> and the second gear set <NUM> may be the same as that described above with respect to <FIG> and <FIG>, except that the epicyclic sun gear <NUM> may be operatively connected to the first planet gear carrier <NUM>. The first gear set <NUM> may remain axially positioned along the axis <NUM> between the electric motor module <NUM> and the second gear set <NUM>, but the second gear set <NUM> may be axially positioned along the axis <NUM> between the first gear set <NUM> and the epicyclic gear set <NUM>.

The epicyclic gear set <NUM> is similar to the configuration shown in <FIG> with the following modifications.

First, the epicyclic sun gear <NUM> may be coupled to the first planet gear carrier <NUM>. For instance, the epicyclic sun gear <NUM> may be integrally formed with or attached to the first planet gear carrier <NUM>. The epicyclic sun gear <NUM> and the first planet gear carrier <NUM> may be fixedly positioned with respect to each other such that the epicyclic sun gear <NUM> does not rotate with respect to the first planet gear carrier <NUM> and the epicyclic sun gear <NUM> and the first planet gear carrier <NUM> are rotatable together about the axis <NUM>. In addition, the epicyclic sun gear <NUM> may include a set of internal teeth <NUM> that may be selectively engaged by the shift collar <NUM>. The set of internal teeth <NUM> may include a plurality of teeth that may be arranged around the axis <NUM> and a repeating pattern. The internal teeth <NUM> may extend toward the axis <NUM> and may be arranged substantially parallel to the axis <NUM>.

Second, the epicyclic planetary ring gear <NUM> may not be rotatable about the axis <NUM>. For instance, the epicyclic planetary ring gear <NUM> may be fixedly mounted to the gear reduction module housing <NUM>.

Third, the epicyclic planet gear carrier <NUM> may be rotatable about the axis <NUM>. The epicyclic planet gear carrier <NUM> may still rotatably support the set of epicyclic planet gears <NUM> but may also include a set of inner teeth <NUM> that may be selectively engaged by the shift collar <NUM>. The set of inner teeth <NUM> may include a plurality of teeth that may be arranged around the axis <NUM> and a repeating pattern. The inner teeth <NUM> may extend toward the axis <NUM> and may be arranged substantially parallel to the axis <NUM>.

Fourth, the epicyclic support bearing assembly <NUM> that rotatably supported the epicyclic planetary ring gear <NUM> in <FIG> may be omitted.

Fifth, a support bearing assembly <NUM> may be provided to rotatably support the epicyclic planet gear carrier <NUM>. The support bearing assembly <NUM> may extend from the gear reduction module housing <NUM> to the epicyclic planet gear carrier <NUM>. For instance, the support bearing assembly <NUM> may be received inside the gear reduction module housing <NUM> and the epicyclic planet gear carrier <NUM> may be received inside the support bearing assembly <NUM>. The support bearing assembly <NUM> may be axially positioned between the epicyclic gear set <NUM> and the gear reduction module cover <NUM>.

Referring to <FIG>, the shift collar <NUM> is shown in the first position. The shift collar <NUM> may couple the epicyclic planet gear carrier <NUM> to the drive pinion <NUM> when in the first position, thereby providing a first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the set of inner teeth <NUM> of the epicyclic planet gear carrier <NUM> when in the first position. Torque may be transmitted from the rotor <NUM> to the first sun gear <NUM> such as via the rotor output flange <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> and the epicyclic sun gear <NUM> via the first set of planet gears <NUM>, from the epicyclic sun gear <NUM> to the epicyclic planet gear carrier <NUM> via the set of epicyclic planet gears <NUM>, and from the epicyclic planet gear carrier <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the first position. The shift collar <NUM> may not couple the first sun gear <NUM>, the first planet gear carrier <NUM>, the second set of planet gears <NUM>, or the epicyclic sun gear <NUM> to the drive pinion <NUM> when in the first position. As such, the first sun gear <NUM>, the first planet gear carrier <NUM>, the second set of planet gears <NUM>, and the epicyclic sun gear <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the first position.

Referring to <FIG>, the shift collar <NUM> is shown in the second position. The shift collar <NUM> may couple the first planet gear carrier <NUM> / epicyclic sun gear <NUM> to the drive pinion <NUM> when in the second position, thereby providing a second drive gear ratio that may differ from the first drive gear ratio. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the internal teeth <NUM> of the epicyclic sun gear <NUM> when in the second position. Torque may be transmitted from the rotor <NUM> to the first sun gear <NUM> such as via the rotor output flange <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> and epicyclic sun gear <NUM> via the first set of planet gears <NUM>, and then from the first planet gear carrier <NUM> and epicyclic sun gear <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the second position. The shift collar <NUM> may not couple the first sun gear <NUM>, the second set of planet gears <NUM>, or the epicyclic planet gear carrier <NUM> to the drive pinion <NUM> when in the second position. As such, the first sun gear <NUM>, second set of planet gears <NUM>, and the epicyclic planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the second position.

Referring to <FIG>, the shift collar <NUM> is shown in the third position. The shift collar <NUM> may couple the second set of planet gears <NUM> to the drive pinion <NUM> when in the third position, thereby providing a third drive gear ratio that may differ from the first drive gear ratio and the second drive gear ratio. As a nonlimiting example, the drive gear ratios may be approximately <NUM>, <NUM>, and <NUM> respectively. The teeth <NUM> of the shift collar <NUM> may engage and mesh with the teeth of the second set of planet gears <NUM> when in the third position. Torque may be transmitted from the rotor <NUM> to the first sun gear <NUM> such as via the rotor output flange <NUM>, from the first sun gear <NUM> to the first planet gear carrier <NUM> via the first set of planet gears <NUM>, from the first planet gear carrier <NUM> to the via the second set of planet gears <NUM>, and then from the second set of planet gears <NUM> to the drive pinion <NUM> via the shift collar <NUM> when the shift collar <NUM> is in the third position. The shift collar <NUM> may not couple the epicyclic planet gear carrier <NUM>, epicyclic sun gear <NUM>, the first sun gear <NUM>, or the first planet gear carrier <NUM> to the drive pinion <NUM> when in the third position. As such, the epicyclic planet gear carrier <NUM>, epicyclic sun gear <NUM>, the first sun gear <NUM>, and the first planet gear carrier <NUM> may be rotatable about the axis <NUM> with respect to the drive pinion <NUM> when the shift collar <NUM> is in the third position.

Referring to <FIG>, the axle assembly <NUM> may optionally include an isolator support <NUM>. The isolator support <NUM> may help support the end of the axle assembly <NUM> that is disposed furthest from the axle housing <NUM> and the differential axis <NUM>. In at least one configuration, the isolator support <NUM> may extend from the gear reduction module housing <NUM> or the gear reduction module cover <NUM> to a cross beam <NUM> that may be part of the chassis of the vehicle. For instance, the cross beam <NUM> may extend in a lateral direction between two frame rails of the vehicle. The isolator support <NUM> may include a first portion <NUM> that may be mounted on the gear reduction module housing <NUM> or the gear reduction module cover <NUM> and a second portion <NUM> that may be mounted to the cross beam <NUM>. The isolator support <NUM> may allow the first portion <NUM> to pivot about an isolator mount axis <NUM> with respect to the second portion <NUM> and may help limit movement and acceleration of the gear reduction module housing <NUM>. For example, it is contemplated that a portion of the isolator support <NUM> may include a resilient member that may be received in a hole in the first portion <NUM>, the second portion <NUM> or both. It is also contemplated that the first portion <NUM> or the second portion <NUM> may be configured as a shock absorber. The isolator support <NUM> may be provided with any of the configurations previously discussed.

An axle assembly having gear set configurations as described above may provide multiple gear ratios or multiple speeds while providing a more compact package space. Moreover, the gear set configurations may allow the difference between gear ratios to be reduced as compared to a two-speed single planetary gear configuration, which may help improve efficiency of the gear reduction unit and drivability of the vehicle. In addition, the configurations described above may allow each gear ratio to be a gear reduction with respect to the rotor speed, which may help reduce the rotational speed of the gear sets and helping reduce heating of the roller bearing assemblies associated with the gear sets and improve bearing life.

Claim 1:
An axle assembly (<NUM>) comprising:
an electric motor (<NUM>) having a rotor (<NUM>) that is rotatable about an axis (<NUM>);
a drive pinion (<NUM>) that extends through the rotor (<NUM>) and is rotatable about the axis (<NUM>);
a gear reduction unit (<NUM>) that includes:
a first gear set (<NUM>) that has a first sun gear (<NUM>) that is operatively connected to the rotor (<NUM>) and is rotatable about the axis (<NUM>), a first planetary ring gear (<NUM>) that is fixedly positioned such that the first planetary ring gear (<NUM>) is not rotatable about the axis (<NUM>), a first set of planet gears (<NUM>) that meshes with the first sun gear (<NUM>) and the first planetary ring gear (<NUM>), and a first planet gear carrier (<NUM>) that rotatably supports the first set of planet gears (<NUM>); and
a second gear set (<NUM>) that has a second sun gear (<NUM>) that is rotatable about the axis (<NUM>), a second set of planet gears (<NUM>) that meshes with the second sun gear (<NUM>) and that is rotatably supported on the first planet gear carrier (<NUM>), wherein members of the second set of planet gears (<NUM>) have a smaller diameter than members of the first set of planet gears (<NUM>); and
a shift collar (<NUM>) that is rotatable about the axis (<NUM>) with the drive pinion (<NUM>) and that is moveable along the axis (<NUM>) between a first position in which the shift collar (<NUM>) couples the first planet gear carrier (<NUM>) but not the first sun gear (<NUM>) or the second sun gear (<NUM>) to the drive pinion (<NUM>) and a second position in which the shift collar (<NUM>) couples the second sun gear (<NUM>) but not the first sun gear (<NUM>) or the first planet gear carrier (<NUM>) to the drive pinion (<NUM>).