Multi-speed axle assembly with one-way freewheel clutch

Abstract

A vehicle axle assembly is disclosed having an electric motor module, a drive pinion, a planetary gear set, and at least one one-way freewheel clutch. The planetary gear set can operatively connect the electric motor module and the drive pinion. The one-way freewheel clutch can be configured to selectively couple at least two components of the planetary gear set.

Description

TECHNICAL FIELD

[0001] The present invention relates to a multi-speed axle assembly for a vehicle that can have at least one one-way freewheel clutch. BACKGROUND

[0002] A drive axle system having one-way freewheel clutches is disclosed in U.S. Patent Application Serial No. 16 / 827,102.

[0003] SUMMARY

[0004] In at least one embodiment, an axle assembly is provided. The axle assembly includes an electric motor module, a drive pinion, a planetary gear set, and a one-way freewheel clutch. The electric motor module has a rotor rotatable about an axis. The drive pinion is rotatable about the axis. The planetary gear set operatively connects the rotor to the drive pinion. The planetary gear set includes a planet carrier, a sun gear, a ring gear, and a set of planet gears. The planet carrier is rotatable about the axis and is operatively connected to the rotor. The sun gear is rotatable about the axis and is operatively connected to the drive pinion. The ring gear surrounds the sun gear and is rotatable about the axis. The set of planet gears is rotatably supported on the planet carrier. Each member of the set of planet gears is in meshing engagement with the sun gear and the ring gear. The one-way freewheel clutch can be configured to selectively couple at least two components of the planetary gear set. For example, the one-way freewheel clutch can be rotatably disposed on the planet carrier or can extend between the sun gear and the planet carrier. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 is a perspective view of an example of an axle assembly.

[0006] Figure 2 is a cross-sectional view of the axle assembly along section line 2-2

[0007] Figure 3 and Figure 4 illustrates a series of positions that depict the planetary gear set with the one-way freewheel clutch decoupled from the planetary gears.

[0008] Figures 5-7 illustrates a series of positions that depict Figure 3 and Figure 4 the one-way freewheel clutch of

[0009] Figure 8 is an example of a planetary gear set having a one-way freewheel clutch that selectively couples the planetary gears to the planet carrier.

[0010] Figure 9 and Figure 10Examples of a planetary ring gear clutch configured as a belt clutch are shown in a disengaged position and an engaged position, respectively.

[0011] Figure 11 and Figure 12 Examples of a planetary ring gear clutch configured as a multi-plate clutch are shown in a disengaged position and an engaged position, respectively.

[0012] Figure 13 and Figure 14 A one-way freewheel clutch is shown inside a planetary gear set of a planetary gear carrier and the associated torque transfer path.

[0013] Figure 15 and Figure 16 A one-way freewheel clutch is shown axially positioned between a sun gear and a planetary gear carrier of a planetary gear set and the associated torque transfer path. DETAILED DESCRIPTION

[0014] The detailed embodiments of the application disclosed herein are not intended to be exhaustive or limiting of the application as claimed. Rather, the detailed description contains specific details or representative

[0015] Referring to Figure 1 An example of an axle assembly 10 is shown. The axle assembly 10 can be provided for a vehicle, such as a truck, a bus, farm equipment, mining equipment, military transport or armored vehicle, or for cargo loading equipment for land, air, or marine vessels. In one or more embodiments, the vehicle can include a trailer for transporting cargo.

[0016] The axle assembly 10 can provide torque to one or more traction wheel assemblies, which can include tires mounted on wheels. The wheels can be mounted to wheel hubs, which can rotate about a wheel axis.

[0017] One or more axle assemblies can be provided for a vehicle. As referenced Figure 1 and Figure 2 Best shown, the axle assembly 10 can include a housing assembly 20, a differential assembly 22, at least one half shaft 24, and an electric motor module 26. As Figure 2 Best shown, the axle assembly 10 can include a gear reduction module 30.

[0018] Housing assembly

[0019] Referring to Figure 1 , the housing assembly 20 can receive various components of the axle assembly 10. Additionally, the housing assembly 20 can facilitate installation of the axle assembly 10 to a vehicle. In at least one configuration, the housing assembly 20 can include an axle housing 40 and a differential carrier 42.

[0020] The axle housing 40 can receive and can support the axle shafts 24. In at least one configuration, the axle housing 40 can include a center portion 50 and at least one arm portion 52.

[0021] The center portion 50 can be disposed proximate a center of the axle housing 40. The center portion 50 can define a cavity that can at least partially receive the differential assembly 22. As Figure 2 Best shown, a lower region of the center portion 50 can at least partially define an oil pan portion 54 that can contain or collect lubricant 56. The lubricant 56 in the oil pan portion 54 can be splashed by the ring gear of the differential assembly 22 and distributed to lubricate various components.

[0022] Referring to Figure 2 , the center portion 50 can include a carrier mounting surface 58. The carrier mounting surface 58 can facilitate installation of the differential carrier 42 to the axle housing 40. For example, the carrier mounting surface 58 can face and can engage the differential carrier 42 and can have a set of apertures that can align with corresponding apertures on the differential carrier 42. Each aperture can receive a fastener, such as a bolt or stud, that can couple the differential carrier 42 to the axle housing 40.

[0023] Referring to Figure 1 , one or more arm portions 52 can extend from the center portion 50. For example, two arm portions 52 can extend from the center portion 50 in opposite directions and away from the differential assembly 22. The arm portions 52 can have substantially similar configurations. For example, the arm portions 52 can each have a hollow or tubular configuration that can extend around and can receive a corresponding axle shaft 24 and can help isolate or separate the axle shaft 24 or a portion thereof from the surrounding environment. The arm portions 52 or a portion thereof can be integrally formed with the center portion 50 or can not be integrally formed with the center portion. It is also contemplated that the arm portions 52 can be omitted.

[0024] Referring to Figure 1 and Figure 2The differential carrier 42 can be mounted to the central portion 50 of the axle housing 40. The differential carrier 42 can support the differential assembly 22 and can facilitate installation of the electric motor module 26. For example, the differential carrier can include one or more bearing supports that can support bearings, such as a roller bearing assembly, that can rotatably support the differential assembly 22. The differential carrier 42 can also include a mounting flange 60 and a bearing support wall 62.

[0025] Referring to Figure 2 The mounting flange 60 can facilitate installation of the electric motor module 26. As an example, the mounting flange 60 can be configured as a ring that can extend outwardly and away from the axis 70 and can extend around the axis 70. In at least one configuration, the mounting flange 60 can include a set of fastener holes that can be configured to receive fasteners that can secure the electric motor module 26 to the mounting flange 60.

[0026] The bearing support wall 62 can support bearings that can rotatably support other components of the axle assembly 10. For example, the bearing support wall 62 can support bearings that can rotatably support the drive pinion gear 84, rotatably support a rotor of the electric motor module 26, or both. The bearing support wall 62 can extend in an axial direction away from the axle housing 40 and can extend around the axis 70. The bearing support wall 62 can define a bore that can extend along or around the axis 70 and receive the drive pinion gear 84 and the bearings that rotatably support the drive pinion gear 84. The bearing support wall 62 can be integrally formed with the differential carrier 42 or can be a separate component that is secured or fastened to the differential carrier 42.

[0027] Differential assembly, drive pinion, and half shafts

[0028] Referring to Figure 2 The differential assembly 22 can be at least partially received in the central portion 50 of the housing assembly 20. The differential assembly 22 can rotate about a differential axis 80 and can transmit torque to the half shafts 24 and the wheels. The differential assembly 22 can be operatively connected to the half shafts 24 and can permit the half shafts 24 to rotate at different rotational speeds in a manner known to those skilled in the art. The differential assembly 22 can have a ring gear 82 that can have teeth that mate or mesh with teeth of a gear portion of the drive pinion gear 84. Accordingly, the differential assembly 22 can receive torque from the drive pinion gear 84 via the ring gear 82 and transmit torque to the half shafts 24.

[0029] The drive pinion 84 can provide torque to the ring gear 82. In axle assemblies that include the gear reduction module 30, the drive pinion 84 can operatively connect the gear reduction module 30 to the differential assembly 22. In at least one configuration, the drive pinion 84 can rotate about the axis 70 and can be rotatably supported within another component, such as the bearing support wall 62.

[0030] Referring to Figure 1 The half shafts 24 can transmit torque from the differential assembly 22 to corresponding wheel hubs and wheels. Two half shafts 24 can be provided such that each half shaft 24 extends through a different arm portion 52 of the axle housing 40. The half shafts 24 can extend along and rotate about an axis, such as the differential axis 80. Each half shaft 24 can have a first end and a second end. The first end can be operatively connected to the differential assembly 22. The second end can be disposed opposite the first end and can be operatively connected to a wheel. Optionally, a gear reduction can be provided between the half shaft 24 and the wheel.

[0031] Electric motor module

[0032] Referring to Figure 2 The electric motor module 26 (which can also be referred to as an electric motor) can be mounted to the differential carrier 42 and can be operatively connected to the differential assembly 22. For example, the electric motor module 26 can provide torque to the differential assembly 22 via the drive pinion 84 and the gear reduction module 30, as will be discussed in greater detail below. The electric motor module 26 can be disposed primarily or entirely outside of the differential carrier 42. Additionally, the electric motor module 26 can be positioned axially between the axle housing 40 and the gear reduction module 30. In at least one configuration, the electric motor module 26 can include a motor housing 100, a coolant jacket 102, a stator 104, a rotor 106, at least one rotor bearing assembly 108, and a cover 110.

[0033] The motor housing 100 can extend between the differential carrier 42 and the cover 110. The motor housing 100 can be mounted to the differential carrier 42 and the cover 110. For example, the motor housing 100 can extend from the mounting flange 60 of the differential carrier 42 to the cover 110. The motor housing 100 can extend about the axis 70 and can define a motor housing cavity 120. The motor housing cavity 120 can be disposed interior to the motor housing 100 and can have a generally cylindrical configuration. The bearing support wall 62 of the differential carrier 42 can be positioned interior to the motor housing cavity 120. Further, the motor housing 100 can extend continuously about the bearing support wall 62 and can be spaced apart therefrom. In at least one configuration, the motor housing 100 can have an outer side 122, an inner side 124, a first end surface 126, a second end surface 128, and one or more ports 130.

[0034] The outer side 122 can face away from the axis 70 and can define an outer surface or outer side surface of the motor housing 100.

[0035] The inner side 124 can be disposed opposite the outer side 122. In one or more configurations, the inner side 124 can be disposed at a substantially constant radial distance from the axis 70.

[0036] The first end surface 126 can extend between the outer side 122 and the inner side 124. The first end surface 126 can be disposed at an end of the motor housing 100 that can face the differential carrier 42. For example, the first end surface 126 can be disposed adjacent the mounting flange 60 of the differential carrier 42. The motor housing 100 and the first end surface 126 can be received interior to the mounting flange 60 or can not be received interior to the mounting flange.

[0037] The second end surface 128 can be disposed opposite the first end surface 126. As such, the second end surface 128 can be disposed at an end of the motor housing 100 that can face and can engage the cover 110. The second end surface 128 can extend between the outer side 122 and the inner side 124 and can be received interior to the cover 110 or can not be received interior to the cover.

[0038] The one or more ports 130 can extend through the motor housing 100. The ports 130 can be configured as through-holes that can extend from the outer side 122 to the inner side 124. The ports 130 can allow coolant (such as a fluid, like water, a water / antifreeze mixture, etc.) to flow into and out of the coolant jacket 102, as will be discussed in greater detail below.

[0039] The coolant jacket 102 can help cool or remove heat from the stator 104. The coolant jacket 102 can be received in the motor housing cavity 120 of the motor housing 100 and can engage the inner side 124 of the motor housing 100. The coolant jacket 102 can extend axially between the differential carrier 42 and the cover 110. For example, the coolant jacket 102 can extend axially from the differential carrier 42, the cover 110, or both. Further, the coolant jacket 102 can extend around the axis 70 and the stator 104. In this way, the stator 104 can be at least partially received in the coolant jacket 102 and can be surrounded by the coolant jacket. Further, the coolant jacket 102 can extend in a radial direction from the stator 104 to the inner side 124 of the motor housing 100. In at least one configuration, the coolant jacket 102 can include a plurality of channels 140.

[0040] The channels 140 can extend at least partially around the axis 70 and can be disposed opposite the stator 104. The channels 140 can be configured to have an open side that can face away from the axis 70 and toward the inner side 124 of the motor housing 100. Coolant can be provided to the coolant jacket 102 via the first port 130 and can be exhausted from the coolant jacket 102 via the second port 130. For example, coolant can flow from the first port 130 into the channels 140, receive heat from the stator 104 as the coolant flows through the channels 140, and be exhausted at the second port 130. One or more baffles can be provided for the coolant jacket 102 that can reverse or change the direction of coolant flow to help deliver coolant from the first port 130 to the second port 130.

[0041] The stator 104 can be received in the motor housing 100. For example, the stator 104 can be received in the motor housing cavity 120. The stator 104 can be fixedly positioned relative to the coolant jacket 102. For example, the stator 104 can extend around the axis 70 and can include stator windings that can be received inside the coolant jacket 102 and can be fixedly positioned relative to the coolant jacket.

[0042] The rotor 106 can extend around the axis 70 and can rotate about the axis. The rotor 106 can be received inside the stator 104, the coolant jacket 102, and the motor housing cavity 120 of the motor housing 100. The rotor 106 can rotate about the axis 70 relative to the differential carrier 42 and the stator 104. Further, the rotor 106 can be spaced apart from the stator 104 but can be disposed in close proximity to the stator 104. The rotor 106 can include magnets or ferromagnetic material that can facilitate current generation or can be induction based. The rotor 106 can extend around and can be supported by the bearing support wall 62.

[0043] One or more rotor bearing assemblies 108 can rotatably support the rotor 106. For example, the rotor bearing assemblies 108 can receive the bearing support walls 62 of the differential carrier 42 and can be received inside the rotor 106. The rotor 106 can be operatively connected to the drive pinion 84. For example, a coupling, such as a rotor output flange 150, can operatively connect the rotor 106 to the gear reduction module 30, which in turn can be operatively connected with the drive pinion 84.

[0044] A cover 110 can be mounted to the motor housing 100 and can be disposed opposite the axle housing 40 and the differential carrier 42. For example, the cover 110 can be mounted to an end or end surface of the motor housing 100, such as the second end surface 128, which can be disposed opposite the differential carrier 42. As such, the cover 110 can be spaced apart from and can not engage the differential carrier 42. The cover 110 can be provided in different configurations. In at least one configuration, the cover 110 can include a first side 160 and a second side 162. The first side 160 can face and can engage the motor housing 100. The second side 162 can be disposed opposite the first side 160. The second side 162 can face away from and can be disposed opposite the motor housing 100. The cover 110 can also include or define a motor cover opening, which can be a through hole through which the drive pinion 84 can extend.

[0045] Gear reduction module and clutch

[0046] Reference is made to Figure 2 FIG. 1 shows an example of the gear reduction module 30. The gear reduction module 30 can transfer torque between the electric motor module 26 and the differential assembly 22. As such, the gear reduction module 30 can facilitate operatively connecting the electric motor module 26 and the differential assembly 22.

[0047] The gear reduction module 30 can be disposed outside of the differential carrier 42 and can be partially or entirely disposed outside of the electric motor module 26. For example, the gear reduction module 30 can include a gear reduction module housing 170, which can receive the gears of the gear reduction module 30. The gear reduction module housing 170 can be provided in different configurations. For example, the gear reduction module housing 170 can be a separate component that is mounted to the cover 110 or can be integrally formed with the cover 110. The gear reduction module housing 170 can extend from the second side 162 of the cover 110 in a direction that extends away from the electric motor module 26. A gear reduction module cover 172 can be disposed on the gear reduction module housing 170 and can be removable to provide access to components located inside the gear reduction module housing 170.

[0048] The gear reduction module 30 can be provided in different configurations. In each configuration, the gear reduction module 30 can have an epicyclic or planetary gear set 200 that can operatively connect the rotor 106 to the drive pinion 84. Further, the planetary gear set 200 can include a sun gear 210, a set of planet gears 212, a planet ring gear 214, and a planet carrier 216. A planet ring gear clutch 220 can be associated with the planetary gear set 200. Also as Figures 3-8 and Figures 13-16 As best shown, at least one one-way freewheel clutch 222, 222', 222" can be associated with the planetary gear set 200.

[0049] Referring primarily to Figure 2 and Figure 3 The sun gear 210 can be disposed proximate a center of the planetary gear set 200. The sun gear 210 can rotate with the drive pinion 84 about the axis 70. For example, the sun gear 210 can encircle the drive pinion 84 and can be coupled to the drive pinion 84 in any suitable manner, such as with mating splines.

[0050] The set of planet gears 212 can be arranged about the sun gear 210. One or more planet gears 212 can be provided. Each planet gear 212 can have teeth that can mesh with teeth of the sun gear 210 that extend away from the axis 70 and that can mesh with teeth of the planet ring gear 214 that extend toward the axis 70. The planet gears 212 can be rotatably supported on the planet carrier 216. For example, each planet gear 212 or each member of the set of planet gears can encircle a corresponding planet pin that can extend from the planet carrier 216 and that can rotate about a corresponding planet gear axis 218 relative to the planet carrier 216. The planet gear axis 218 can be positioned at a constant or substantially constant radial distance from the axis 70.

[0051] The planet ring gear 214 can extend about the axis 70 and can receive the set of planet gears 212. As such, the planet ring gear 214 can encircle the sun gear 210 and the set of planet gears 212. The planet ring gear 214 can be rotatable relative to the gear reduction module housing 170 about the axis 70. The planet ring gear 214 can have teeth that extend toward the axis 70 and that can be arranged in a repeating pattern about the axis 70. For clarity, some of the teeth are omitted in Figures 3-10 .

[0052] The planet carrier 216 can help rotatably support the set of planet gears 212. Further, the planet carrier 216 can rotate about the axis 70. The planet carrier 216 can extend toward the rotor 106 and can be operatively connected to the rotor. For example, the planet carrier 216 can be directly coupled to the rotor 106 or indirectly coupled to the rotor 106, such as via the rotor output flange 150.

[0053] The planet ring clutch 220 can control rotation of the planet ring gear about the axis 70. In Figures 3-8 and Figures 13-16 , the planet ring clutch 220 is represented by a box extending between the planet ring gear 214 and a stationary or grounded component, such as the gear reduction module housing 170. The box is marked with an X when the planet ring clutch 220 is engaged to cause the planet ring clutch 220 to be coupled or grounded. The box is empty and not marked with an X when the planet ring clutch 220 is at least partially disengaged and the planet ring gear 214 and the grounded component are uncoupled, disconnected, or unlocked from one another to permit the planet ring gear 214 to rotate about the axis 70. The box can represent a single clutch or multiple clutches. The planet ring clutch 220 can be operated or actuated by any suitable type of actuator, such as an electric actuator, an electromechanical actuator, a mechanical actuator, a pneumatic actuator, a hydraulic actuator, etc.

[0054] The planet ring clutch 220 can have any suitable configuration, some examples of which are shown in Figures 9-12 .

[0055] In Figure 9 and Figure 10 , the planet ring clutch 220 is configured as a band clutch that partially encircles the planet ring gear 214. In this configuration, the band clutch can have a first tab 230, a second tab 232, and a band 234. The first tab 230 can extend from a first end of the band clutch to the band 234. The second tab 232 can extend from a second end of the band clutch to an opposite end of the band 234. The band 234 can extend around the axis 70 and the planet ring gear 214. The first tab 230 and the second tab 232 can be operatively connected to an actuator 240.

[0056] In Figure 9 , the planet ring clutch 220 is shown in a disengaged position in which the planet ring clutch 220 is spaced apart from the planet ring gear 214.

[0057] In Figure 10In the diagram, the planetary ring gear clutch 220 is shown in the engaged position, in which the belt 234 engages the planetary ring gear 214 to apply a force that can slow or stop the rotation of the planetary ring gear 214 about axis 70. The planetary ring gear clutch 220 can move from the disengaged position to the engaged position by compressing the belt 234 around the planetary ring gear 214 (this can be achieved by reducing the distance between the first tab 230 and the second tab 232). As an example, the actuator 240 can retract the shaft 242 to move the first tab 230 toward the stationary second tab 232. The force applied to the planetary ring gear 214 by the planetary ring gear clutch 220 can be reduced by extending the shaft 242.

[0058] exist Figure 11 and Figure 12 The diagram illustrates an example of a planetary ring gear clutch 220 configured as a multi-plate clutch that can surround a planetary ring gear 214 and can be actuated in a direction extending along axis 70. For example, the multi-plate clutch may include a set of first clutch plates 250 and a set of second clutch plates 252. The first clutch plates 250 may extend from the outer side of the planetary ring gear 214 away from axis 70, and may be rotatably fixed relative to the planetary ring gear 214. The second clutch plates 252 may be spaced apart from the planetary ring gear 214 and may extend from a mounting plate or other stationary or grounded component toward axis 70, such that the second clutch plates 252 are prevented from rotating about axis 70. The first clutch plates 250 and the second clutch plates 252 may be arranged in an alternating pattern and may be staggered.

[0059] exist Figure 11 In the diagram, the planetary ring gear clutch 220 is shown in the disengaged position, in which the first clutch disc 250 and the second clutch disc 252 are spaced apart from each other, thereby allowing the planetary ring gear 214 and the first clutch disc 250 to rotate freely about axis 70 relative to the second clutch disc 252.

[0060] exist Figure 12 In the diagram, the planetary ring gear clutch 220 is shown in the engaged position, in which the actuator compresses the first clutch plate 250 and the second clutch plate 252 to engage, applying a force that can slow or stop the rotation of the planetary ring gear 214 about the axis 70. The compression force can be controlled to prevent the first clutch plate 250 and the planetary ring gear 214 from rotating relative to the second clutch plate 252, or to allow limited slip (wherein the first clutch plate 250 and the planetary ring gear 214 can rotate relative to the second clutch plate 252 about the axis 70, but at a reduced speed due to the frictional force applied between the first clutch plate 250 and the second clutch plate 252).

[0061] Referring to Figures 3-8 and Figures 13-16 At least one one-way freewheel clutch 222, 222', 222" can be associated with the planetary gear set 200. The one-way freewheel clutch (which can also be referred to as an overrunning clutch) can be of any suitable type, such as a dog clutch, a ratchet clutch, a pawl clutch, etc. The one-way freewheel clutch 222, 222', 222" can selectively couple one rotatable component in the planetary gear set 200 to another rotatable component in the planetary gear set 200. The one-way freewheel clutch 222, 222', 222" can be overrunning when the rotational speed of the planetary ring gear 214 is less than the input speed.

[0062] In Figures 3-7 , the one-way freewheel clutch 222 selectively couples one planetary gear 212 to another planetary gear 212. In these figures, four one-way freewheel clutches 222 are shown; however, a greater or lesser number of one-way freewheel clutches can be provided. The one-way freewheel clutch 222 can be rotatably disposed on the planetary carrier 216. For example, the one-way freewheel clutch 222 can be rotatable relative to the planetary carrier 216 about a clutch axis 260. The clutch axis 260 can extend parallel or substantially parallel to the axis 70 and can be disposed closer to the axis 70 than the planetary gear axis 218, which is disposed proximate to the axis 70. A biasing member, such as a spring, can be associated with each one-way freewheel clutch 222. The biasing member can urge the one-way freewheel clutch 222 to rotate about the clutch axis 260 in a clockwise direction from the perspective shown.

[0063] Each one-way freewheel clutch 222 can be engageable with two components in the set of planetary gears 212 to prevent rotation of the planetary gears 212 relative to the planetary carrier 216. In at least one configuration, the one-way freewheel clutch 222 can generally resemble a parallelogram in shape, and the one-way freewheel clutch can have a first prong 270 and a second prong 272 disposed opposite the first prong 270. The first prong 270 and the second prong 272 can engage with different planetary gears 212 to prevent rotation as will be discussed in greater detail below.

[0064] Starting with Figure 3 , the operation of the planetary gear set 200 and the one-way freewheel clutch 222 will now be described. Solid dots are shown on the sun gear 210, the planetary gears 212, and the planetary ring gear 214 to help highlight the rotational movement of these components from figure to figure.

[0065] In Figure 3In this example, and from the perspective shown, the rotor 106 can rotate the planet carrier 216 in a counterclockwise direction (compare

[0066] In this example, and from the perspective shown, the rotor 106 can rotate the planet carrier 216 in a counterclockwise direction (compare Figure 3 and Figure 4 are best understood). In response, the planet gears 212 can rotate in a clockwise direction about their respective planet gear axes 218 relative to the planet carrier 216 and can travel along the planet ring gear 214. In response, the sun gear 210 can rotate in a counterclockwise direction about the axis 70. The one-way freewheel clutch 222 does not couple the pairs of planet gears 212 to one another. Instead, the first and second tips 270, 272 can slide along or bounce off of the tip surfaces of the teeth of the planet gears 212 (i.e., the tip surfaces can be the surfaces of the teeth that face away from and are disposed farthest from the planet gear axes 218) without preventing or stopping rotation of the planet gears 212 relative to one another. In this way, the one-way freewheel clutch 222 can permit rotation of the set of planet gears 212 relative to the planet carrier 216, the sun gear 210, and the planet ring gear 214 when the planet ring gear 214 is prevented from rotating about the axis 70.

[0067] Referring to Figures 5-7 In this example, and from the perspective shown, the rotor 106 can rotate the planet carrier 216 in a counterclockwise direction (compare

[0068] Figure 5 The low speed mode is shown at start-up or from a stationary rest position. The planet ring gear clutch 220 is disengaged to permit rotation of the planet ring gear 214. The one-way freewheel clutch 222 can also be disengaged to permit rotation of the planet gears 212 relative to the planet carrier 216.

[0069] In this example, and from the perspective shown, the rotor 106 can rotate the planet carrier 216 in a counterclockwise direction (compare Figure 5 and Figure 6Best understood, the torque supplied by rotor 106 to planetary gear carrier 216 can initiate rotation of planetary gear carrier 216 in a counterclockwise direction from the angle shown. In response, planetary gears 212 can initiate rotation in a counterclockwise direction about their respective planetary gear axes 218. This, in turn, causes planetary ring gear 214 to initiate rotation in a counterclockwise direction about axis 70. Sun gear 210 can remain stationary.

[0070] One-way freewheel clutch 222 from Figure 5 The disengagement position in the middle moves to Figure 6 In the engagement position, the one-way freewheel clutch 222 engages a pair of planetary gears 212. Since the one-way freewheel clutch 222 does not require a significant rotation to engage the pair of planetary gears 212, therefore... Figure 5 The position shown is to Figure 6 The rotational travel distance at the indicated position is relatively short. Each one-way freewheel clutch 222 can rotate clockwise about the clutch axis 260 of the one-way freewheel clutch from the indicated angle under the biasing force applied by the biasing member. The tips of the one-way freewheel clutches 222 can then engage the corresponding planetary gears 212 in such a way that they stop the counterclockwise rotation of the planetary gears 212 and thus stop the rotation of the planetary gears 212 relative to each other. For example, the first tip 270 of the one-way freewheel clutch 222 can contact the first member of the set of planetary gears 212 and can be received between adjacent teeth of the first member of the set of planetary gears 212. The second tip 272 can contact the second member of the set of planetary gears 212 and can be received between the teeth of the second member of the set of planetary gears 212. The first tip 270 and the second tip 272 can contact the side surface of the corresponding planetary gear tooth, the root surface between adjacent planetary gear teeth, or a combination thereof. Two one-way freewheel clutches 222 can engage each planetary gear 212 when multiple planetary gears 212 are provided and the number of planetary gears 212 is equal to the number of one-way freewheel clutches 222.

[0071] refer to Figure 7 Once the one-way freewheel clutch 222 engages, the sun gear 210 can begin to rotate, and thus the drive pinion 84 can begin to rotate. More specifically, when the one-way freewheel clutch 222 prevents the planetary gears 212 from rotating relative to the planetary gear carrier 216, the planetary gear carrier 216, planetary gears 212, planetary ring gears 214, and sun gear 210 can rotate together about axis 70 (indicated by the two arrowed lines on the planetary ring gear 214) and can not rotate relative to each other. Therefore, a 1:1 transmission ratio can be set between the rotor 106 and the drive pinion 84.

[0072] Referring to Figure 8 , another configuration is shown in which one-way freewheel clutches 222' selectively couple the planetary gears 212 to the planetary gear carrier 216. This configuration can have the same structure as that shown in Figures 3-7 , except for the configuration of the one-way freewheel clutches 222'. Each one-way freewheel clutch 222' can have a first prong 270, but not a second prong 272. In this way, each one-way freewheel clutch 222' can be engageable with one member of the set of planetary gears 212. More specifically, the one-way freewheel clutch 222' can permit rotation of the corresponding planetary gear 212 in a high speed mode (in which the planetary ring gear clutch 220 is engaged, as in Figure 3 and Figure 4 , as previously discussed), and can rotate to resist rotation of the corresponding planetary gear 212 relative to the planetary gear carrier 216 in a low speed mode (in which the planetary ring gear clutch 220 is disengaged, and the first prong 270 of the one-way freewheel clutch 222' is received between the teeth of the associated planetary gear 212, similar to Figures 5-7 , as previously discussed).

[0073] Referring to Figures 13-16 , configurations are shown in which one-way freewheel clutches 222" selectively couple the sun gear 210 to the planetary gear carrier 216. In these configurations, the planetary gear carrier 216 can be operatively connected to the rotor 106 (such as via the rotor output flange 150), and the sun gear 210 can be coupled to the drive pinion 84, as previously discussed. Further, the one-way freewheel clutches 222" extend between the sun gear 210 and the planetary gear carrier 216.

[0074] In these figures, an example of a torque transfer path between the electric motor module 26 and the drive pinion 84 is represented by an arrowed line. For simplicity, the torque transfer path is illustrated above the axis line 70; however, similar torque transfers can be provided below the axis line 70. The torque transfer path is primarily described in the context of transferring torque from the electric motor module 26 to the drive pinion 84; however, the torque transfer path can be bidirectional, and can facilitate the transfer of torque from the drive pinion 84 to the electric motor module 26 under various operating conditions (such as during regenerative braking).

[0075] Referring to Figure 13 and Figure 14The one-way freewheel clutch 222” is housed within the planetary gear carrier 216, and the sun gear 210 is also housed within the one-way freewheel clutch 222”. Thus, the one-way freewheel clutch 222” can surround the axis 70 and the sun gear 210, while the planetary gear carrier 216 can surround the one-way freewheel clutch 222”. The one-way freewheel clutch 222” can extend from the sun gear 210 to the planetary gear carrier 216. Although only one one-way freewheel clutch 222” is shown, it is contemplated that multiple one-way freewheel clutches 222” could be provided.

[0076] exist Figure 13 The diagram illustrates the low-speed mode. In low-speed mode, the planetary ring gear clutch 220 can disengage, allowing the planetary ring gear 214 to rotate freely about axis 70. Torque can be transmitted between the planetary gear carrier 216 and the sun gear 210 via the one-way freewheel clutch 222". For example, torque can be transmitted from the rotor 106 to the planetary gear carrier 216, such as the rotor output flange 150, and from the planetary gear carrier 216 to the sun gear 210 and the drive pinion 84 via the one-way freewheel clutch 222".

[0077] exist Figure 14 The diagram illustrates the high-speed mode. In high-speed mode, the planetary ring gear clutch 220 can engage, allowing the rotation of the planetary ring gear 214 about axis 70 to be slowed or stopped. Torque can be transmitted between the planetary gear carrier 216 and the sun gear 210 via this set of planetary gears 212 (instead of via the one-way freewheel clutch 222"). Thus, the one-way freewheel clutch 222" can be overridden and allows the sun gear 210 to rotate faster than the planetary gear carrier 216 in high-speed mode.

[0078] refer to Figure 15 and Figure 16 Another configuration is shown, in which a one-way freewheel clutch 222” is positioned along axis 70 between the sun gear 210 and the planetary gear carrier 216. Thus, the one-way freewheel clutch 222” can extend axially from the sun gear 210 or in a direction parallel to axis 70 to the planetary gear carrier 216. Figure 13 and Figure 14 Similar to the configuration in the previous example, the one-way freewheel clutch 222” can be housed within the planetary gear carrier 216. Alternatively, the sun gear 210 is housed within the one-way freewheel clutch 222”, in which case the one-way freewheel clutch 222” can surround the axis 70 and the sun gear 210, while the planetary gear carrier 216 can surround the one-way freewheel clutch 222”. Figure 13 and Figure 14The configuration shown can provide reduced power loss when the one-way freewheel clutch 222" is overrun, compared to this configuration.

[0079] In the low speed mode, the planetary ring gear clutch 220 can be disengaged so that the planetary ring gear 214 is free to rotate about the axis 70. Torque can be transmitted between the planet carrier 216 and the sun gear 210 via the one-way freewheel clutch 222". For example, torque can be transmitted from the rotor 106 to the planet carrier 216, such as the rotor output flange 150, and can be transmitted from the planet carrier 216 to the sun gear 210 and drive pinion 84 via the one-way freewheel clutch 222". Figure 15 In the high speed mode, the planetary ring gear clutch 220 can be engaged so that rotation of the planetary ring gear 214 about the axis 70 can be slowed or prevented. Torque can be transmitted between the planet carrier 216 and the sun gear 210 via the set of planetary gears 212 (rather than via the one-way freewheel clutch 222"). As such, the one-way freewheel clutch 222" can be overrun and can permit the sun gear 210 to rotate faster than the planet carrier 216 in the high speed mode.

[0080] Figure 16 The above-described configuration allows the axle assembly to be set at a variety of operating speeds or a variety of gear ratios without the use of a shift collar to engage a desired gear ratio. More specifically, a change between operating speeds or gear ratios can be performed without the use of a shift collar that can rotate with the drive pinion and is selectively engageable with different components of the planetary gear set. Eliminating the shift collar can allow for faster engagement of a desired operating speed because there is no need to manipulate the rotational speed of the electric motor to sufficiently synchronize the rotational speed of the components of the planetary gear set with the rotational speed of the drive pinion in order to perform a shift of the shift collar from one position to another. Eliminating the shift collar can also help to reduce weight, reduce complexity, and reduce packaging space requirements. The present invention also allows for smooth control of the rotational speed of the planetary ring gear so that there is a continuous change in the effective overall gear ratio, which not only allows for quick mode changes, but also reduces the perceived discomfort of mode changes. Because the gear ratio changes are primarily achieved by controlling the rotational speed of the planetary ring gear rather than by the rotational speed of multiple components and shift collar actuators, the control algorithm can be greatly simplified. During torque reversal events, such as during regenerative braking, the rotational speed of the planetary ring gear can be controlled to reduce or eliminate freewheeling motion in order to improve regenerative braking efficiency.

[0081] The above-described configuration allows the axle assembly to be set at a variety of operating speeds or a variety of gear ratios without the use of a shift collar to engage a desired gear ratio. More specifically, a change between operating speeds or gear ratios can be performed without the use of a shift collar that can rotate with the drive pinion and is selectively engageable with different components of the planetary gear set. Eliminating the shift collar can allow for faster engagement of a desired operating speed because there is no need to manipulate the rotational speed of the electric motor to sufficiently synchronize the rotational speed of the components of the planetary gear set with the rotational speed of the drive pinion in order to perform a shift of the shift collar from one position to another. Eliminating the shift collar can also help to reduce weight, reduce complexity, and reduce packaging space requirements. The present invention also allows for smooth control of the rotational speed of the planetary ring gear so that there is a continuous change in the effective overall gear ratio, which not only allows for quick mode changes, but also reduces the perceived discomfort of mode changes. Because the gear ratio changes are primarily achieved by controlling the rotational speed of the planetary ring gear rather than by the rotational speed of multiple components and shift collar actuators, the control algorithm can be greatly simplified. During torque reversal events, such as during regenerative braking, the rotational speed of the planetary ring gear can be controlled to reduce or eliminate freewheeling motion in order to improve regenerative braking efficiency.

[0082] ​While the foregoing describes exemplary embodiments, these embodiments are not intended to describe all possible forms of the application. Rather, the words used in this specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the application. Additionally, the features of various implementing embodiments can be combined to form further embodiments of the application.

Claims

1. An axle assembly comprising: an electric motor module having a rotor rotatable about an axis; a drive pinion rotatable about the axis; a planetary gear set operatively connecting the rotor to the drive pinion, the planetary gear set including: a planetary carrier rotatable about the axis and operatively connected to the rotor; a sun gear rotatable about the axis and operatively connected to the drive pinion; a planetary ring gear surrounding the sun gear and rotatable about the axis; and a set of planetary gears rotatably supported on the planetary carrier, wherein each member of the set of planetary gears meshes with the sun gear and the planetary ring gear; and a one-way freewheel clutch rotatably disposed on the planetary carrier and engageable with at least one member of the set of planetary gears.

2. The axle assembly of claim 1, wherein, each member of the set of planetary gears is rotatable about a planetary gear axis relative to the planetary carrier, the one-way freewheel clutch is rotatable about a clutch axis relative to the planetary carrier, and the clutch axis is disposed closer to the axis than the planetary gear axis disposed proximate to the axis.

3. The axle assembly of claim 1, wherein, the one-way freewheel clutch is engageable with one member of the set of planetary gears.

4. The axle assembly of claim 3, wherein, when the one-way freewheel clutch is received between teeth of a first member of the set of planetary gears, the one-way freewheel clutch prevents rotation of the first member of the set of planetary gears relative to the planetary carrier.

5. The axle assembly of claim 1, wherein, the one-way freewheel clutch is engageable with two members of the set of planetary gears.

6. The axle assembly of claim 5, wherein, when the one-way freewheel clutch is received between teeth of a first member of the set of planetary gears and between teeth of a second member of the set of planetary gears, and the planetary ring gear is rotatable about the axis, the one-way freewheel clutch prevents rotation of the set of planetary gears relative to the planetary carrier.

7. The axle assembly of claim 5, wherein, when a first tip of the one-way freewheel clutch contacts a first member of the set of planetary gears and is received between adjacent teeth of the first member of the set of planetary gears, and a second tip of the one-way freewheel clutch contacts a second member of the set of planetary gears and is received between teeth of the second member of the set of planetary gears, the one-way freewheel clutch prevents rotation of the set of planetary gears relative to the planetary carrier.

8. The axle assembly of claim 5, wherein, when the one-way freewheel clutch prevents rotation of the set of planetary gears relative to the planetary carrier, the planetary ring gear, the planetary carrier, and the sun gear are rotatable together about the axis.

9. The axle assembly of claim 5, wherein, the one-way freewheel clutch permits rotation of the set of planetary gears relative to the planetary carrier when the planetary ring gear is prevented from rotating about the axis.

10. The axle assembly of claim 9, wherein, The one-way freewheel clutch permits rotation of the set of planetary gears relative to the sun gear and the planetary ring gear when the planetary ring gear is prevented from rotating about the axis.

11. The axle assembly of claim 1, wherein, A planetary ring gear clutch controls rotation of the planetary ring gear about the axis.

12. The axle assembly of claim 11, wherein, The planetary ring gear clutch is a belt clutch partially encircling the planetary ring gear.

13. The axle assembly of claim 11, wherein, The planetary ring gear clutch is a multi-plate clutch encircling the planetary ring gear and actuatable in a direction extending along the axis.

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