Axle assembly with a shifting mechanism

Abstract

Disclosed is an axle assembly having a shift mechanism and a drive pinion. The shift mechanism includes a shift collar, a linkage, and an actuator. The linkage is coupled to the shift collar. The actuator is coupled to the linkage. The linkage is received in a drive pinion bore of the drive pinion.

Description

Technical Field

[0001] The present invention relates to an axle assembly having a shift mechanism. Background

[0002] U.S. Patent No. 11,441,657 discloses an axle assembly having a shift mechanism. Overview

[0003] The present invention relates to an axle assembly. The axle assembly includes a drive pinion, a transmission, and a shift mechanism. The drive pinion is rotatable about an axis. The drive pinion has a drive pinion bore. The drive pinion bore extends along the axis. The drive pinion bore extends from a first end of the drive pinion toward a second end of the drive pinion. The second end of the drive pinion is disposed opposite the first end. The transmission has a set of gears. The shift mechanism includes a shift collar, a linkage, and an actuator. The shift collar is rotatable about the axis with the drive pinion. The shift collar is movable relative to the drive pinion along the axis. The linkage is coupled to the shift collar. The linkage is received in the drive pinion bore of the drive pinion. The actuator is coupled to the linkage. The actuator is configured to move the linkage and the shift collar along the axis to selectively connect members of the set of gears to the drive pinion.

[0004] The linkage may extend along the axis. The linkage may rotate about the axis with the shift collar. The linkage may be disposed inside the shift collar. The linkage may be fixedly coupled to the shift collar.

[0005] The drive pinion may include a drive pinion extension. The drive pinion extension is rotatable about the axis. The shift collar may be disposed on the drive pinion extension. The linkage may be received inside the drive pinion extension.

[0006] The drive pinion extension may have a slot. The slot may extend in an axial direction relative to the axis. A fastener may be received in the slot. The fastener may couple the linkage to the shift collar. The fastener may be fixedly coupled to the linkage and the shift collar. The fastener may move in the slot in the axial direction.

[0007] When the actuator moves the shift collar toward the actuator, the linkage, the fastener, and the shift collar may move in a first direction along the axis. When the actuator moves the shift collar away from the actuator, the linkage, the fastener, and the shift collar may move in a second direction along the axis, the second direction being opposite the first direction.

[0008] The axle assembly may include an end cap. The end cap may be disposed at an end of the axle assembly. The end cap may define a recess. A support bearing may be received within the recess. The support bearing may rotatably support a drive pinion. A fastener may be received within the recess.

[0009] The axle assembly may have an electric motor. The electric motor may include a rotor. The rotor may rotate about an axis. The rotor may surround the drive pinion. The drive pinion may surround a linkage.

[0010] The axle assembly may include an axle housing and a differential carrier. The axle housing and the differential carrier may cooperate to define an internal cavity. A differential assembly may be received within the internal cavity. An actuator may be received within the internal cavity. The actuator may be mounted to the differential carrier. The actuator may be mounted to the axle housing.

[0011] The differential assembly may rotate about a differential axis. The actuator may be axially positioned relative to the axis between a first end of the drive pinion and the differential axis.

[0012] The actuator may be positioned farther from the drive pinion compared to the positioning of the differential axis from the drive pinion.

[0013] The actuator may be disposed outside the internal cavity. The actuator may be mounted to the axle housing.

[0014] The actuator may be disposed along the axis.

[0015] The drive pinion may be rotatably coupled to the linkage. The linkage may rotate about the axis with the drive pinion. The linkage may move along the axis relative to the drive pinion.

[0016] The drive pinion may be rotatably coupled to the linkage within a drive pinion bore. The drive pinion and the linkage may be rotatably coupled with mating splines.

[0017] A support shaft may extend along the axis. The support shaft may be surrounded by the linkage. The support shaft may be surrounded by a shift collar. The support shaft may rotate about the axis. The linkage may rotate about the axis with the support shaft. Description of the Drawings

[0018] Figure 1 is a perspective view of an example of the axle assembly.

[0019] Figure 2 is a cross-sectional view of the axle assembly taken along section line 2-2.

[0020] Figure 3 is a cross-sectional view of a portion of the axle assembly along section line 3-3, with the electric motor module omitted for clarity.

[0021] Figure 4 is an exploded view showing examples of a pinion extension, a shift collar, and a support bearing that can be provided for a shift mechanism of an axle assembly.

[0022] Figure 5 is a partial plan view of a part of an axle assembly, showing an example of an actuator of a shift mechanism that is offset from the rotational axis of a pinion gear.

[0023] Figure 6 is a cross-sectional view of a second configuration of the axle assembly along section line 2-2.

[0024] Figure 7 is a cross-sectional view of a third configuration of the axle assembly along section line 2-2.

[0025] Figure 8 is a cross-sectional view of a fourth configuration of the axle assembly along section line 2-2.

[0026] Figure 9 is what can be provided for Figure 8 a cross-sectional view of a part of a pinion gear of an axle assembly.

[0027] Figure 10 is Figure 8 a side view of the shift collar and linkage shown.

[0028] Figure 11 is a cross-sectional view of a fifth configuration of the axle assembly along section line 2-2. DETAILED DESCRIPTION

[0029] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely illustrative of the various forms and alternative forms in which the present invention can be implemented. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Thus, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to implement the present invention in various ways.

[0030] It should also be understood that although the terms first, second, etc. are used in some cases herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the various described embodiments, the first element can be called the second element, and similarly, the second element can be called the first element. The first element and the second element are both elements, but they are not the same element.

[0031] The terms used in the description of the various embodiments described are for the purpose of describing particular embodiments only and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, as used herein, the term "and / or" refers to and encompasses any and all possible combinations of one or more of the associated listed items. It should be further understood that when used in this specification, the terms "comprises", "comprising", "includes", and / or "including" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0032] Reference Figure 1 , an example of an axle assembly 10 is shown. The axle assembly 10 can be provided for a motor vehicle, such as a truck, agricultural machinery, military transport or armaments vehicle, or for a cargo loading device for a land, air, or undersea vessel. In one or more embodiments, the vehicle can include a trailer for transporting cargo.

[0033] The axle assembly 10 is a drive axle assembly. The drive axle assembly is configured to provide torque to one or more wheel assemblies. The wheel assemblies can be rotatably supported on the axle assembly 10. The wheel assemblies can include tires disposed on the wheels. The wheels can be mounted to hubs that can rotate about a wheel axis. The hubs can be rotatably disposed on the axle assembly 10.

[0034] In some configurations, the axle assembly 10 includes a housing assembly 20, a differential assembly 22, a pair of half shafts 24, an electric motor 26, a transmission 28, a drive pinion 30, and a shift mechanism 32. The positioning of the differential assembly 22, the electric motor 26, and / or the transmission 28 can be different from that shown. For example, the differential assembly 22 can be positioned between the electric motor 26 and the transmission 28. It is also contemplated that, in some configurations, the electric motor 26 can be positioned away from the axle assembly 10 and can not be part of the axle assembly 10. For purposes of illustration, the axle assembly 10 will be described primarily in the Figures 1 to 3 context of the configuration shown.

[0035] Reference Figure 1 , the housing assembly 20 houses the various components of the axle assembly 10. In addition, the housing assembly 20 can facilitate mounting the axle assembly 10 to the vehicle. In some configurations, the housing assembly 20 includes an axle housing 40 and a differential carrier 42. In some configurations, the housing assembly 20 includes an electric motor housing 44, a transmission housing 46, an end cap 48, or a combination thereof.

[0036] ReferenceFigure 1 and Figure 2 , the axle housing 40 can receive and support the half shafts 24. The axle housing 40 can include a central portion 50 and at least one arm portion 52.

[0037] The central portion 50 can be disposed near the center of the axle housing 40. The central portion 50 can help to define an internal cavity 54 that can receive the differential assembly 22.

[0038] One or more arm portions 52 can extend from the central portion 50. For example, two arm portions 52 can extend from the central portion 50 in opposite directions and away from the differential assembly 22. Each arm portion 52 can have a hollow configuration or a tubular configuration that can extend around a corresponding half shaft 24 and can receive the corresponding half shaft and can help to separate or isolate the half shaft 24 from the surrounding environment. A wheel hub can be rotatably disposed on the arm portion 52 and can be connected to the half shaft 24.

[0039] The differential carrier 42 is configured to be mounted to the axle housing 40. For example, the differential carrier 42 can be mounted to the central portion 50 of the axle housing 40. The differential assembly 22 can be rotatably supported on the differential carrier 42. The differential carrier 42 and the axle housing 40 can cooperate to define the internal cavity 54.

[0040] The electric motor housing 44 can extend around or surround the electric motor 26. In some configurations, the electric motor housing 44 extends between the differential carrier 42 and the transmission housing 46.

[0041] The transmission housing 46 can extend around or surround the transmission 28. In some configurations, the transmission housing 46 extends between the electric motor housing 44 and the end cap 48.

[0042] The end cap 48 can be disposed at an end of the housing assembly 20. For example, the end cap 48 can be mounted to an end of the transmission housing 46 that faces away from the differential assembly 22. The end cap 48 can define a recess 56, which is best shown in Figure 2 . The recess 58 can be disposed along an axis 80 about which the drive pinion 30 can rotate, as will be discussed in more detail below.

[0043] Reference Figure 2, a differential assembly 22 is disposed within a housing assembly 20. For example, the differential assembly 22 may be disposed within an internal cavity 54. The differential assembly 22 (which may also be referred to as an axle differential) can transfer torque to the half shafts 24 of the axle assembly 10 and permit the half shafts 24 and the wheel assemblies to rotate at different speeds in a manner known to those skilled in the art. For example, the differential assembly 22 may have a ring gear 60 that may be fixedly mounted to the differential housing. The ring gear 60 and the differential housing may rotate about a differential axis 62. The differential housing may receive differential gears that may be operatively connected to the half shafts 24.

[0044] The half shafts 24 are configured to transfer torque between the differential assembly 22 and the corresponding wheel hubs. For example, two half shafts 24 may be provided such that each half shaft 24 extends through a different arm portion 52 of the axle housing 40. The half shafts 24 may rotate about a wheel axis. The wheel axis may be the same as or different from the differential axis 62.

[0045] The electric motor 26 is configured to provide torque, such as propulsion torque or regenerative braking torque. The propulsion torque may be used, for example, to propel the vehicle in a forward or backward direction. The propulsion torque may also be used to keep the vehicle in a stationary position or to help reduce, limit, or prevent the vehicle from rolling back, such as when the vehicle is on an inclined surface. Regenerative braking may provide regenerative braking torque. When the electric motor 26 is used to brake the vehicle or slow down the vehicle's speed, regenerative braking can capture kinetic energy. The recovered energy may be transferred from the wheel assemblies to drive the electric motor 26. Thus, the electric motor 26 may act as a generator and may be used to charge a power source (such as a battery). The electric motor 26 may be electrically connected to the power source via an inverter in a manner known to those skilled in the art.

[0046] The electric motor 26 includes a stator 70 and a rotor 72. The stator 70 may be fixedly positioned relative to the electric motor housing 44. The stator 70 may surround the rotor 72. The rotor 72 may rotate relative to the stator 70 about an axis 80. The rotor 72 may surround the drive pinion 30. The electric motor 26 may be mounted to or positioned within the housing assembly 20, such as within the electric motor housing 44.

[0047] The transmission 28 facilitates torque transfer between the electric motor 26 and the drive pinion 30. The torque transfer can be bidirectional. The transmission 28 can provide gear reduction and multiple gear ratios between the rotor 72 and the drive pinion 30. The transmission 28 can be of any suitable type. For example, the transmission 28 can be a countershaft transmission, an epicyclic transmission (e.g., a transmission having a planetary gear set), etc. A countershaft transmission can include a single countershaft or multiple countershafts. Examples of axle assemblies having a single countershaft transmission are disclosed in U.S. Patent Nos. 11,002,352 and 11,209,072. Examples of axle assemblies having a double countershaft transmission are disclosed in U.S. Patent Nos. 10,989,288, 11,207,976, and 11,220,176. Examples of axle assemblies having an epicyclic transmission are disclosed in U.S. Patent Nos. 11,038,396 and 11,428,297. The disclosures of the references in the preceding three sentences are incorporated herein by reference in their entireties.

[0048] Figure 2 and Figure 3 Examples of the transmission 28 configured as a double countershaft transmission are shown in. However, it should be understood that the transmission 28 is not limited to a countershaft transmission and can be of any suitable type as discussed above. The transmission 28 includes one or more sets of gears. For example, in Figure 3 the configuration shown, the transmission 28 can include a gear set 90 for the drive pinion, a first countershaft gear set 92, and a second countershaft gear set 94. The gears of the first countershaft gear set 92 and the second countershaft gear set 94 can be disposed on a first countershaft 96 and a second countershaft 96', respectively, and can rotate therewith. In a single countershaft configuration, the second countershaft gear set 94 can be omitted. In other configurations, the gear set 90 for the drive pinion, the first countershaft gear set 92, and the second countershaft gear set 94 can be replaced with one or more epicyclic gear sets or planetary gear sets.

[0049] In Figure 3 the gear set 90 for the drive pinion can include a plurality of gears, some or all of which can be selectively coupled to the drive pinion 30. These gears can rotate independently of each other. In the configuration shown, the gear set 90 for the drive pinion includes a first gear 100, a second gear 102, a third gear 104, and a fourth gear 106; however, it should be understood that more or fewer gears can be provided. The first gear 100 can mesh with one or more first countershaft gears 110, 110'. The second gear 102 can mesh with one or more second countershaft gears 112, 112'. The third gear 104 can mesh with one or more third countershaft gears 114, 114'. The fourth gear 106 can mesh with one or more fourth countershaft gears 116, 116'.

[0050] Reference Figure 2 , the drive pinion 30 operatively connects the transmission 28 to the differential assembly 22. In this way, the drive pinion 30 can transmit torque between the differential assembly 22 and the transmission 28. The drive pinion 30 is rotatable about an axis 80. The drive pinion 30 is disposed inside the housing assembly 20 and can be rotatably supported on the differential carrier 42 via one or more roller bearing assemblies. The drive pinion 30 has a first end 120, a second end 122, a gear portion 124, a shaft portion 126, and a drive pinion bore 128. The drive pinion 30 may further include a drive pinion extension 130.

[0051] The first end 120 faces the differential assembly 22. The first end 120 may be a part of the gear portion 124.

[0052] The second end 122 is disposed opposite the first end 120. In this way, the second end 122 may face away from the differential assembly 22. The second end 122 may be a part of the shaft portion 126.

[0053] The gear portion 124 includes a plurality of teeth that mate with corresponding teeth on the ring gear 60 of the differential assembly 22. The gear portion 124 may be disposed at or near an end of the shaft portion 126. The gear portion 124 may be integrally formed with the shaft portion 126 or may be provided as a separate component that can be fixedly disposed on the shaft portion 126.

[0054] The shaft portion 126 extends from the gear portion 124. For example, the shaft portion 126 may extend from the gear portion 124 to the second end 122. The shaft portion 126 may extend along or around the axis 80.

[0055] The drive pinion bore 128 is disposed in the drive pinion 30. The drive pinion bore 128 extends along the axis 80. The drive pinion bore 128 extends from the first end 120 toward the second end 122. In some configurations, the drive pinion bore 128 is a through-hole. For example, the drive pinion bore 128 may extend along the axis 80 from the first end 120 of the drive pinion 30 to the second end 122 of the drive pinion 30. The drive pinion bore 128 may have any suitable configuration. For example, the drive pinion bore 128 may have a circular cross-section.

[0056] Reference Figures 2 to 4, the drive pinion extension 130 increases the axial length of the drive pinion 30. For example, the drive pinion extension 130 can be a separate component mounted to the shaft portion 126 such that the drive pinion extension 130 can rotate about the axis 80 with the shaft portion 126. For example, the drive pinion extension 130 can be mounted to the shaft portion 126 by mating splines. The drive pinion extension 130 can extend from the second end 122 of the drive pinion 30 in a direction away from the gear portion 124. The drive pinion extension 130 can be fixedly positioned relative to the drive pinion 30 such that the drive pinion extension 130 cannot move along the axis 80 relative to the shaft portion 126. It is also contemplated that the drive pinion extension 130 can be integrally formed with the drive pinion 30. For ease of reference, unless otherwise noted, the term "drive pinion" is used herein to refer to the drive pinion 30 with or without the drive pinion extension 130.

[0057] Main reference Figure 4 , the drive pinion extension 130 (if provided) defines a portion of the drive pinion bore 128. In some configurations, the drive pinion extension 130 has a first extension end 140, a second extension end 142, one or more slots 144, and splines 146. Optionally, the drive pinion extension 130 can include a socket 148.

[0058] The first extension end 140 faces the shaft portion 126 of the drive pinion 30. If the drive pinion extension 130 is integrally formed with the drive pinion 30 as a single unitary component, the first extension end 140 can be omitted.

[0059] The second extension end 142 is disposed opposite the first extension end 140. Thus, the second extension end 142 faces away from the differential assembly 22. The portion of the drive pinion bore 128 disposed in the drive pinion extension 130 can extend from the first extension end 140 toward the second extension end 142 or to the second extension end 142. The second extension end 142 can be received within and rotatably supported by a support bearing 150 that rotatably supports the drive pinion extension 130. The support bearing 150 can be received within a recess 56 of the end cap 48, as Figure 2 shown.

[0060] Reference Figure 2 and Figure 4, one or more slots 144 may be provided for driving the pinion extension 130. The slots 144 may extend or elongate in the axial direction relative to the axis 80 or in a direction extending along or parallel to the axis 80. The slots 144 may be end-closed slots extending between a first slot end and a second slot end. The slots 144 may extend away from the axis 80 from the pinion bore 128. For example, the slots 144 may extend from the pinion bore 128 through the pinion extension 130 to the outer surface of the pinion extension 130 that is away from the axis 80. One slot 144 is visible in Figure 4 Two slots 144 are visible in Figure 2 These slots 144 are aligned with each other and are disposed on opposite sides of the axis 80.

[0061] Main reference Figure 4 , the splines 146 facilitate the installation and axial movement of the shift collar, as will be discussed in more detail below. The splines 146 may include a plurality of teeth that extend from the outer side of the pinion extension 130 in a direction extending away from the axis 80 and the pinion bore 128. The splines 146 may be axially positioned between the first extension end 140 and the second extension end 142. For example, the splines 146 may be axially positioned between the first extension end 140 and the slot 144.

[0062] The socket 148 (if provided) receives the pinion 30. The socket 148 may extend from the first extension end 140. When the pinion extension 130 is provided as a separate part, the first end 120 of the pinion 30 may be disposed inside the socket 148. The pinion 30 may be fastened to the socket 148 in any suitable manner, such as by fasteners, threaded connections, mating splines, etc. It is also contemplated that the socket 148 may be provided for the pinion 30, and the pinion extension 130 may be received inside the socket.

[0063] Reference Figure 2 , the shift mechanism 32 facilitates coupling the pinion 30 to the transmission 28. For example, the shift mechanism 32 is configured to selectively connect a gear of the transmission 28 (such as a member of the gear set 90 of the pinion) to the pinion 30. The shift mechanism 32 may connect one gear to the pinion 30 at a time. In some configurations, the gear coupled to the pinion 30 may rotate about the axis 80 with the pinion 30. The shift mechanism 32 may have any suitable configuration. In some configurations, the shift mechanism 32 includes a shift collar 160, a linkage 162, and an actuator 164. The shift mechanism 32 may also include fasteners 166.

[0064] The shift collar 160 (in Figure 4Best shown in , it can rotate around axis 80 with the drive pinion 30. Additionally, the shift collar 160 can move along axis 80 relative to the drive pinion 30. The shift collar 160 can selectively connect the gears of the transmission 28 to the drive pinion 30. For example, the shift collar 160 can selectively connect members of the gear set 90 of the drive pinion to the drive pinion 30, as will be discussed in more detail below. In at least one configuration, the shift collar 160 can include a first end 170, a second end 172, a shift collar hole 174, shift collar splines 176, and a shift collar gear 178.

[0065] The first end 170 can face the drive pinion 30. The first end 170 can surround axis 80.

[0066] The second end 172 is arranged to be opposite to the first end 170. Thus, the second end 172 can face away from the drive pinion 30.

[0067] The shift collar hole 174 can extend along axis 80 between the first end 170 and the second end 172. The shift collar hole 174 can be configured as a through hole that can extend from the first end 170 to the second end 172. The drive pinion 30 or the drive pinion extension 130 can be received inside the shift collar hole 174.

[0068] The shift collar splines 176 are configured to couple the shift collar 160 to the drive pinion 30, such as to the drive pinion extension 130 of the drive pinion 30. The shift collar splines 176 can be provided in the shift collar hole 174. The shift collar splines 176 can include teeth that extend towards axis 80. The shift collar splines 176 can cooperate with the splines 146. The mating splines can allow the shift collar 160 to move in the axial direction or along axis 80, while restricting or inhibiting the shift collar 160 from rotating around axis 80 relative to the drive pinion 30. Thus, when the shift collar splines 176 cooperate with the splines 146, the shift collar 160 can rotate around axis 80 with the drive pinion 30.

[0069] The shift collar gear 178 can engage with the gears of the transmission 28. The shift collar gear 178 can be provided between the first end 170 and the second end 172 of the shift collar 160. The shift collar gear 178 can be arranged opposite to the shift collar hole 174. The shift collar gear 178 can have teeth that can be arranged around axis 80 and can extend away from axis 80 and the shift collar hole 174.

[0070] Reference Figure 2, The linkage 162 is operatively connected to the shift collar 160 and the actuator 164. The linkage 162 is received within the pinion bore 128. Thus, if a pinion extension 130 is provided, the linkage 162 can be received within the pinion 30 and the pinion extension 130. The pinion 30, the pinion extension 130, or both can surround the linkage 162. The linkage 162 can extend along the axis 80. The linkage 162 is coupled to the shift collar 160. Thus, the linkage 162 can rotate about the axis 80 with the shift collar 160. The linkage 162 can be disposed within the shift collar 160. The linkage 162 can be fixedly coupled to the shift collar 160. The linkage 162 can have any suitable configuration. For example, the linkage 162 can be configured as a shaft, a rod, or the like.

[0071] The actuator 164 is configured to move the shift collar 160 along the axis 80. For example, the actuator 164 is configured to move the linkage 162 and the shift collar 160 along the axis 80 to selectively connect or selectively couple the gears of the transmission 28 to the pinion 30 or to disconnect the shift collar 160 from the gears of the transmission 28. The actuator 164 is coupled to the linkage 162.

[0072] The actuator 164 can be disposed in different positions. In some configurations, the actuator 164 is disposed within or received within the internal cavity 54 of the housing assembly 20. For example, the actuator 164 can be disposed within the axle housing 40, the differential carrier 42, or both. In Figure 2 the illustrated configuration, the actuator 164 is disposed within the internal cavity 54 and within the differential carrier 42. The actuator 164 can be axially positioned relative to the axis 80 between the first end 120 of the pinion 30 and the differential axis 62. For example, the actuator 164 can be axially positioned along the axis 80 or relative to the axis between the first end 120 and the differential axis plane 168, which can be disposed substantially perpendicular to the axis 80. The term "substantially perpendicular" is used herein to denote a feature or axis that is the same as or very close to perpendicular, and includes features within ±3° of being perpendicular to each other. In this configuration, the actuator 164 can be mounted to the differential carrier 42.

[0073] In Figure 6 the illustrated configuration, the actuator 164 is disposed such that it is Figure 2The configuration shown is further from the first end 120 of the drive pinion 30. For example, the actuator 164 can be positioned further from the drive pinion 30 compared to the positioning of the differential axis 62 relative to the drive pinion 30. For example, the actuator 164 can be positioned axially along or relative to the axis 80 between the differential axis plane 168 and the end of the axle housing 40 or the bowl-shaped cover (e.g., the left end as viewed from the perspective shown in Figure 2 ). In such a configuration, the actuator 164 can be disposed within the axle housing 40 and can be mounted to the axle housing 40.

[0074] In Figure 7 the configuration shown, the actuator 164 is not disposed within or received in the internal cavity 54 of the housing assembly 20. Instead, the actuator 164 or a portion thereof can be disposed outside the internal cavity 54. In Figure 7 , the actuator 164 is mounted to the axle housing 40 and is disposed outside the axle housing 40. In such a configuration, the linkage 162 can extend through a hole in the end of the axle housing 40 or the bowl-shaped cover to facilitate connection to the actuator 164.

[0075] Referring primarily to Figure 2 , the fastener 166 couples the linkage 162 to the shift collar 160. The fastener 166 can be of any suitable type, such as a pin, a staple, a threaded fastener, etc. The fastener 166 can be fixedly coupled to the shift collar 160, the linkage 162, or both. For example, the fastener 166 can project from the linkage 162 into one or more fastener holes 180 in the shift collar 160, which are best shown in Figure 4 . The fastener 166 can be received in one or more slots 144 of the drive pinion 30 or the drive pinion extension 130. Thus, the fastener 166 can move axially within the one or more slots 144. In some configurations, the fastener 166 can be received in the recess 56 of the end cap 48, such as when the shift collar 160 is actuated away from the drive pinion 30.

[0076] The shift collar 160, the linkage 162, and the fastener 166 can move together along the axis 80. The length of the slot 144 can limit the distance that the shift collar 160, the linkage 162, and the fastener 166 can move along the axis 80. For example, when the fastener 166 engages or contacts the closed end of the slot 144, the axial movement of the shift collar 160, the linkage 162, and the fastener 166 can be inhibited.

[0077] The shift collar 160, linkage 162, and fastener 166 can move along axis 80 in a first direction 190 and in a second direction 192 that is set to be opposite to the first direction 190. When the actuator 164 causes the shift collar 160 to move toward the actuator 164 or move left from the Figure 2 , Figure 6 and Figure 7 shown perspective, the shift collar 160, linkage 162, and fastener 166 can move along axis 80 in the first direction 190. When the actuator 164 causes the shift collar 160 to move away from the actuator 164 or move right from the Figure 2 , Figure 6 and Figure 7 shown perspective, the shift collar 160, linkage 162, and fastener 166 can move along axis 80 in the second direction 192.

[0078] In Figure 2 , Figure 6 and Figure 7 the shown configuration, the actuator 164 may or may not be disposed along axis 80 or intersect the axis. The actuator 164 disposed along axis 80 or that can intersect axis 80 can be directly coupled to the linkage 162. As some non-limiting examples, the actuator 164 can be a linear actuator or a solenoid that can apply a force on the linkage 162 to move the linkage 162 along axis 80. Referring to Figure 5 , an example of a partial plan view is shown, showing the actuator 164 offset from and not intersecting axis 80. In this configuration, the actuator 164 can be coupled to the linkage 162 through a secondary linkage 200 that can connect the actuator to the linkage 162. The secondary linkage 200 can have any suitable configuration, such as a shaft, a cable (such as a push-pull cable), etc.

[0079] The actuator 164 can cause the secondary linkage 200, linkage 162, and shift collar 160 to move along axis 80, which is shown in dashed lines in Figure 5 . Moving left along axis 80 or in the first direction 190 from the Figure 2 and Figure 4 shown position can cause the shift collar gear 178 to disengage from the fourth gear 106 and move to a first neutral position disposed between the fourth gear 106 and the third gear 104. Further actuation in the first direction 190 can cause the shift collar gear 178 to move into engagement with the third gear 104, followed by a second neutral position between the third gear 104 and the second gear 102, and move into engagement with the second gear 102.

[0080] Referring to Figure 8, showing another configuration of the axle assembly. This configuration includes a housing assembly 20, a differential assembly 22, a pair of half shafts 24, an electric motor 26, and a transmission 28, as described previously. The axle assembly also includes a drive pinion 30' and a shift mechanism 32'.

[0081] The drive pinion 30' is the same as the drive pinion 30 described previously, but may have a shorter axial length. Additionally, the drive pinion 30' has mating features 210', which are best shown in Figure 9 Noting that Figure 9 only a portion of the drive pinion 30' is shown.

[0082] Primarily referring to Figure 9 and Figure 10 , the mating features 210' are configured to rotatably couple the drive pinion 30' to the linkage 162' of the shift mechanism 32' such that the drive pinion 30' and the linkage 162' can rotate together about an axis 80. The mating features 210' allow the linkage 162' to move relative to the drive pinion 30' along the axis 80. The mating features 210' may be provided in the drive pinion bore 128. The mating features 210' can have any suitable configuration. For example, the mating features 210' can be configured to have an outwardly convex configuration, an inwardly concave configuration, or a combination thereof. As some examples, the mating features 210' can be pins, keys, one or more teeth, etc. In Figure 9 , the mating features 210' are depicted as one or more teeth, such as splines or spline teeth extending toward the axis 80. The mating features 210' can be located inside the gear portion 124, the shaft portion 126, or both. In the illustrated configuration, the mating features 210' are located inside the gear portion 124 of the drive pinion 30'.

[0083] Referring to Figure 8 , the shift mechanism 32' facilitates coupling the drive pinion 30' to the transmission 28 and is configured to selectively connect the gears of the transmission 28 (such as members of the gear set 90 of the drive pinion) to the drive pinion 30', as discussed previously with respect to the shift mechanism 32. The shift mechanism 32 includes an actuator 164 as discussed previously and a shift collar 160', a linkage 162', and a support shaft 220'.

[0084] Referring to Figure 8 and Figure 10, the shift collar 160' can rotate about the axis 80 with the drive pinion 30' and can move along the axis 80 relative to the drive pinion 30'. The shift collar 160' can selectively connect the gears of the transmission 28 (such as the members of the gear set 90 of the drive pinion) to the drive pinion 30', as discussed previously. In at least one configuration, the shift collar 160' is fixedly coupled to or integrally formed with the linkage 162', and includes a shift collar bore 174' and a shift collar gear 178, as described previously.

[0085] The shift collar bore 174' extends along the axis 80 and can be configured as a through hole. The support shaft 220' can be received inside the shift collar bore 174'.

[0086] The linkage 162' extends from the shift collar 160' and operatively connects the shift collar 160' to the drive pinion 30' and the actuator 164. The linkage 162' can rotate about the axis 80 with the shift collar 160'. The linkage 162 is received in the drive pinion bore 128 and can project from the first end 120 to the outside of the drive pinion 30' and from the second end 122 of the drive pinion 30'. Thus, the linkage 162' can have an axial length greater than that of the drive pinion 30'. In some configurations, the linkage 162' is configured as a hollow tube extending along the axis 80. The linkage 162' can surround the axis 80 and the support shaft 220'. In some configurations, the linkage 162' includes a linkage mating feature 222' and a shift block 224'.

[0087] The linkage mating feature 222' is configured to rotatably couple the linkage 162' to the drive pinion 30' and allow the linkage 162' to move along the axis 80 relative to the drive pinion 30'. The linkage mating feature 222' can be disposed in the drive pinion bore 128. The linkage mating feature 222' engages the mating feature 210' of the drive pinion 30' and can have any suitable configuration compatible with the mating feature 210'. For example, the linkage mating feature 222' can be configured to have an outwardly convex configuration, an inwardly concave configuration, or a combination thereof. As some examples, the linkage mating feature 222' can be a recess, a pin, a key, one or more teeth, etc. In Figure 10In the configuration shown, the linkage mating feature 222' is depicted as one or more teeth (such as splines or spline teeth) that extend away from the axis 80 and are received between corresponding teeth of the mating feature 210' of the drive pinion 30' throughout the axial travel distance of the linkage 162'. The linkage mating feature 222' may have an axial length greater than that of the mating feature 210' of the drive pinion 30'. The linkage mating feature 222' may be located within the gear portion 124, the shaft portion 126, or both. In the configuration shown, at least a portion of the linkage mating feature 222' is located within the gear portion 124 of the drive pinion 30'.

[0088] The shift block 224' operatively connects the linkage 162' to the actuator 164. Depending on the size of the drive pinion bore 128, the shift block 224' may be integrally formed with the linkage 162' or may be a separate component fastened to the linkage 162'. For example, the shift block 224' may be a separate component that is fixedly attached to the linkage 162' after the linkage 162' is inserted through the drive pinion bore 128. The shift block 224' is disposed at or near an end of the linkage 162' opposite the shift collar 160'. In this way, the shift block 224' may be disposed within the axle housing 40, the differential carrier 42, or both. The shift block 224' may have any suitable configuration compatible with the actuator 164 and the linkage 162'. In Figure 8 and Figure 11 , a simplified depiction of the actuator 164 is shown, where the shift block 224' may move along or parallel to the axis 80.

[0089] The support shaft 220' supports the shift collar 160' and the linkage 162'. The support shaft 220' extends along the axis 80 and may be surrounded by the shift collar 160', the linkage 162', or both. The support shaft 220' may extend through the shift collar 160' and the linkage 162'. For example, the support shaft 220' may project from an end of the shift collar 160' and from an end of the linkage 162'. The ends of the support shaft 220' may be supported by the housing assembly 20.

[0090] In some configurations, such as Figure 8 the configuration shown, the support shaft 220' may rotate about the axis 80. In such a configuration, the support shaft 220' may be rotatably supported on a bearing 230', such as a roller bearing assembly. In the configuration shown, one bearing 230' is disposed on the axle housing 40 and another bearing 230' is disposed on the transmission housing 46. The support shaft 220' may not translate along the axis 80.

[0091] In some configurations, the support shaft 220' can rotate about the axis 80 with the shift collar 160' and the linkage 162'. In some configurations, the support shaft 220' can contact or engage the shift collar 160' and / or the linkage 162', but the shift collar 160' and the linkage 162' can slide or translate freely along the axis 80 relative to the support shaft 220'. For example, the support shaft 220' can be connected to the shift collar 160' and / or the linkage 162' by one or more mating features such as keys, pins, teeth, mating splines, etc.

[0092] In some configurations, the support shaft 220' cannot rotate about the axis 80. Figure 11 An example of such a configuration is shown. In this configuration, the bearing 230' can be omitted and the support shaft 220' is stationary. The shift collar 160' and the linkage 162' can rotate about the axis 80 relative to the support shaft 220' and can move along the axis 80 relative to the support shaft 220'. In some configurations, the shift collar 160' and the linkage 162' can be spaced apart from the support shaft 220' such that a gap is provided therebetween.

[0093] One or more bearings 240' can be provided between the support shaft 220' and the shift collar 160' and / or the linkage 162' to facilitate rotation of the shift collar 160' and the linkage 162' relative to the support shaft 220' and translation of the shift collar 160' and the linkage 162' along the axis 80 relative to the support shaft 220'. For example, the bearing 240' can include a plurality of bearing elements such as ball bearings. In Figure 11 FIG., a single bearing 240' is shown, but it should be understood that additional bearings 240' can be provided. It is contemplated that the bearing 240' can move axially with the shift collar 160' and the linkage 162', or the shift collar 160' and the linkage 162' can move axially relative to the bearing 240'.

[0094] One or more bearings 242' can be provided between the support shaft 220' and the shift block 224' to facilitate rotation of the shift collar 160' and the linkage 162' relative to the shift block 224' and translation of the shift collar 160' and the linkage 162' along the axis 80 relative to the shift block 224'. In some configurations, the shift block 224' can surround the bearing 242', and the bearing 242' can surround the linkage 162', and can move axially with the linkage 162' and the shift block 224'. For example, the linkage 162', the shift block 224', and the bearing 242' can move leftward along the axis 80 from the position shown to move the shift collar 160' to the neutral position or engage a different member of the gear set driving the pinion.

[0095] It is contemplated that in Figure 8 and Figure 11 , the actuator 164 may be arranged closer to the drive pinion 30' compared to that shown, such as closer to the differential axis plane 168, or disposed between the differential axis plane 168 and the drive pinion 30', similar to Figure 2 the positioning shown. It is also contemplated that the actuator 164 may also be disposed outside the housing assembly 20, similar to Figure 7 the configuration shown. In such a configuration, the support shaft 220' may be rotatable as in Figure 8 or non-rotatable as in Figure 11 , and an actuator shaft or another linkage may extend from the externally mounted actuator 164 into the internal cavity 54 of the housing assembly 20 to connect the actuator 164 to the linkage 162'.

[0096] The present invention may contribute to reducing the overhang or axial length of the axle assembly. For example, compared to a configuration where the shift mechanism is positioned at the end of the axle assembly adjacent to the transmission, the present invention may allow the shift mechanism to be placed closer to the axle housing. Positioning the shift mechanism at or near the end of the axle assembly adjacent to the transmission increases the overhang or axial length of the axle assembly, increasing the space required to accommodate the axle assembly when installed in a vehicle. For example, in one or more configurations, the present invention may reduce the axial length by approximately 60 mm. Additionally, positioning the shift mechanism at or near the end of the axle assembly requires the housing assembly to extend away from the axis (e.g., in the radial direction) to provide sufficient space to accommodate and package the shift mechanism. The present invention employs a hollow drive pinion that allows the shift mechanism to move closer to the opposite end of the axle assembly, which in turn allows for a end cap to be provided that can be positioned closer to the axis and extend a shorter length along the axis.

[0097] While the above describes exemplary embodiments, these embodiments are not intended to describe all possible forms of the invention. Rather, the words used in this specification are descriptive words rather than restrictive words, and it should be understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of the embodiments of various implementations may be combined to form other embodiments of the invention.

Claims

1. A vehicle axle assembly, comprising: a drive pinion gear rotatable about an axis and having a drive pinion gear hole extending along the axis from a first end of the drive pinion gear toward a second end of the drive pinion gear disposed opposite the first end; a transmission, the transmission comprising a set of gears; as well as A shift mechanism, the shift mechanism comprising: a shift collar rotatable with the drive pinion about the axis and movable relative to the drive pinion along the axis; a linkage coupled to the shift collar, wherein the linkage is received in a drive pinion bore of the drive pinion; and An actuator is coupled to the linkage and is configured to move the linkage and the shift collar along the axis to selectively connect a member of the set of gears to the drive pinion.

2. The axle assembly of claim 1, wherein: The linkage extends along the axis.

3. The axle assembly of claim 1, wherein: The linkage is rotatable with the shift collar about the axis.

4. The axle assembly of claim 1, wherein: The linkage member is arranged inside the shift collar.

5. The axle assembly of claim 1, wherein: The linkage is fixedly coupled to the shift collar.

6. The axle assembly of claim 1, wherein: The drive pinion includes a drive pinion extension rotatable about the axis, wherein the shift collar is disposed on the drive pinion extension and the linkage is received inside the drive pinion extension.

7. The axle assembly of claim 6, wherein: The drive pinion extension has a slot extending in an axial direction relative to the axis, and a fastener is received in the slot and couples the linkage to the shift collar.

8. The axle assembly of claim 7, wherein: The fastener is fixedly coupled to the linkage and the shift collar, and the fastener is movable in the axial direction within the groove.

9. The axle assembly of claim 7, wherein: When the actuator moves the shift collar toward the actuator, the linkage, the fastener, and the shift collar move in a first direction along the axis.

10. The axle assembly of claim 9, wherein: When the actuator moves the shift collar away from the actuator, the linkage, the fastener, and the shift collar move along the axis in a second direction, the second direction being disposed opposite the first direction.

11. The axle assembly of claim 7, wherein: The axle assembly includes an end cap disposed at an end of the axle assembly, wherein the end cap defines a recess in which a support bearing is received, the support bearing rotatably supporting the drive pinion, wherein the fastener is receivable in the recess.

12. The axle assembly of claim 1, wherein: The axle assembly has an electric motor including a rotor rotatable about the axis, the rotor surrounds the drive pinion, and the drive pinion surrounds the linkage.

13. The axle assembly of claim 1, wherein: The actuator is disposed along the axis.

14. The axle assembly of claim 1, wherein: The axle assembly includes an axle housing and a differential carrier that cooperate to define an internal cavity within which the differential assembly and the actuator are received.

15. The axle assembly of claim 14, wherein: The actuator is mounted to the differential carrier.

16. The axle assembly of claim 14, wherein: The differential assembly is rotatable about a differential axis, and the actuator is positioned axially relative to the axis between the first end of the drive pinion and the differential axis.

17. The axle assembly of claim 14, wherein: The actuator is mounted to the axle housing.

18. The axle assembly of claim 1, wherein: The axle assembly includes an axle housing and a differential carrier, the axle housing and differential carrier cooperating to define an internal cavity, the differential assembly and the actuator being received inside the internal cavity, the differential assembly being rotatable about a differential axis, and the actuator being positioned farther from the drive pinion than the differential axis is positioned from the drive pinion.

19. The axle assembly of claim 1, wherein: The axle assembly includes an axle housing and a differential carrier that cooperate to define an internal cavity within which a differential assembly is received, wherein the actuator is disposed outside of the internal cavity.

20. The axle assembly of claim 19, wherein: The actuator is mounted to the axle housing.

21. The axle assembly of claim 1, wherein: The drive pinion is rotatably coupled to the linkage such that the linkage is rotatable with the drive pinion about the axis and is movable along the axis relative to the drive pinion.

22. The axle assembly of claim 21, wherein: The drive pinion is rotatably coupled to the linkage in the drive pinion bore.

23. The axle assembly of claim 22, wherein: The drive pinion and the linkage are rotatably coupled with mating splines.

24. The axle assembly of claim 1 further comprising a support shaft extending along said axis and surrounded by said linkage and said shift collar.

25. The axle assembly of claim 24, wherein: The support shaft is rotatable about the axis.

26. The axle assembly of claim 25, wherein: The linkage is rotatable with the support shaft about the axis.

27. The axle assembly of claim 24, wherein: The support shaft is non-rotatable about the axis, and the linkage is rotatable about the axis relative to the support shaft.

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