Axle assembly with clutch collar

Abstract

An axle assembly having a clutch collar. The axle assembly includes a shaft, a piston, a bearing assembly, and a clutch collar. The piston surrounds the clutch collar. A bearing assembly extends from the piston to the clutch collar and facilitates rotation of the clutch collar relative to the piston.

Description

Technical Field

[0001] The invention relates to an axle assembly having a clutch collar and a clutch collar shifting mechanism. background

[0003] An axle assembly having a clutch collar actuator mechanism is disclosed in US Pat. No. 10,113,628.

[0004] Overview

[0005] The invention relates to an axle assembly. The axle assembly comprises a shaft, a clutch collar, a piston and a bearing assembly. The shaft is rotatable about an axis. The clutch collar is disposed on the shaft. The clutch collar is movable relative to the shaft along the axis. The piston surrounds the clutch collar. The bearing assembly extends between the piston and the clutch collar. The bearing assembly facilitates the rotation of the clutch collar relative to the piston.

[0006] The axle assembly may include an outer housing. The outer housing may surround the piston. The outer housing may surround a clutch collar. The outer housing and the piston may cooperate to at least partially define a cavity therebetween. The clutch collar may move along the axis from a first position to a second position. When pressurized fluid is provided to the cavity, the clutch collar may move along the axis.

[0007] The axle assembly may include an inter-axle differential unit. The inter-axle differential unit may be disposed on a shaft. The inter-axle differential unit may have a first side gear. When the clutch collar is in a first position, the first side gear may rotate relative to the first shaft about a first axis. When the clutch collar is in a second position, the first shaft, the clutch collar, and the first side gear may rotate together about the first axis.

[0008] The outer shell may include a fluid channel. The fluid channel may extend from the cavity. The fluid channel may extend through the outer shell. Pressurized fluid is provided to the cavity via the fluid channel.

[0009] The axle assembly may include a first seal. The first seal may surround the axis. The first seal may surround the piston. The first seal may engage the outer housing. The axle assembly may include a second seal. The second seal may surround the axis. The second seal may surround the piston. The second seal may engage the outer housing. The first seal and the second seal may cooperate with the outer housing and the piston to define a cavity. The second seal may be disposed closer to the axis than the first seal.

[0010] The fluid passage in the outer housing may include a port. The port may be disposed adjacent the cavity. The port may be axially positioned between the first seal and the second seal.

[0011] The piston may surround the bearing assembly. The bearing assembly may surround the clutch collar. The bearing assembly may move along the axis with the clutch collar and the piston.

[0012] The piston may be spaced apart from the clutch collar. The piston may not contact the clutch collar.

[0013] The axle assembly may include a biasing member. The biasing member may extend from the shaft to the clutch collar. The biasing member may be surrounded by the clutch collar. The biasing member may be surrounded by the piston. The biasing member may drive the clutch collar and the piston to move along the axis. The biasing member may drive the clutch collar and the piston to move along the axis from the second position to the first position. The clutch collar may couple the component to the shaft when in the second position. The clutch collar may not couple the component to the shaft when in the first position.

[0014] The pin may extend from the outer housing toward the axis. The pin may engage with the piston to limit movement of the piston relative to the outer housing along the axis. The piston may have a slot. The pin may be received in the slot.

[0015] The clutch collar may have an outer collar side. The outer collar side may face away from the axis. The piston may have an inner piston side. The inner piston side may surround the outer collar side. The bearing assembly may extend from the inner piston side to the outer collar side. The inner piston side and the outer collar side may be arranged at an inclined angle relative to the axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a perspective view of an example of an axle assembly.

[0017] Figure 2 is a partial cross-sectional view of the axle assembly along section line 2-2.

[0018] Figure 3 and Figure 4 yes Figure 2 An enlarged view of a portion of FIG. 1 shows a first example of a clutch collar shift mechanism and a shift collar in a first position and a second position, respectively.

[0019] Figure 5 and Figure 6 Yes Figure 3 and Figure 4 Exploded views of some of the components shown.

[0020] Figure 7 and Figure 8 is an enlarged view showing a second example of a clutch collar shift mechanism and a shift collar in a first position and a second position, respectively.

[0021] Fig. 9 Yes Figure 7 and Figure 8Exploded views of some of the components shown. DETAILED DESCRIPTION

[0022] 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 and alternative forms in which the present invention may be implemented. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to employ the present invention in various ways.

[0023] 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 element. For example, without departing from the scope of the various embodiments described, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element. Both the first element and the second element are elements, but they are not the same element.

[0024] The terms used in the description of the various embodiments described are only for the purpose of describing specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and the appended claims, the singular forms "one", "a kind of" and "the" are intended to also include plural forms 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 listed related items. It should be further understood that, when used in this specification, the terms "comprising", "comprising", "including" and / or "including" indicate the presence of the narrated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups.

[0025] refer to Figure 1 , shows an example of an axle assembly 10. The axle assembly 10 may be provided for use with any suitable type of vehicle, such as a truck, bus, agricultural equipment, military transport or armament vehicle, or cargo loading equipment for land, air, or watercraft.

[0026] In some configurations, the axle assembly 10 can be part of a vehicle driveline that can include multiple axle assemblies that can be connected in series. For example, the axle assembly 10 can be part of a tandem axle driveline configuration that can include two axle assemblies connected in series. The axle assembly 10 that is operably connected to at least one torque source (such as an electric motor or an internal combustion engine) or is disposed closest to the torque source can be referred to as a first axle assembly. The axle assembly that receives propulsion torque from the torque source through or via the first axle assembly can be referred to as a second axle assembly. Figure 1 , the axle assembly 10 is depicted as a first axle assembly.

[0027] The axle assembly 10 is configured to provide torque to its associated wheel assembly and may provide torque to a second axle assembly. Figure 2 In some configurations shown, the axle assembly 10 includes a housing assembly 20, a first yoke 22, a first shaft 24, an inter-axle differential unit 26, a clutch collar 28, a clutch collar shift mechanism 30, a driven gear 32, a drive pinion 34, a differential assembly 36, at least one half shaft 38, a second shaft 40, a second yoke 42, or combinations thereof.

[0028] refer to Figure 1 and Figure 2 , the housing assembly 20 can receive various components of the axle assembly 10. In addition, the housing assembly 20 can facilitate the installation of the axle assembly 10 to the vehicle. In some configurations, the housing assembly 20 includes an axle housing and a differential carrier. The axle housing receives at least a portion of the differential assembly 36 and can have arm portions that receive and support the half shafts 38. The differential carrier is mounted to the axle housing and supports the differential assembly 36 and a bearing assembly that rotatably supports the differential assembly 36.

[0029] The first yoke 22, if provided, can facilitate coupling the axle assembly 10 to a torque source. It is contemplated that the first yoke 22 can be omitted, such as when the torque source (e.g., an electric motor) is integrated with the axle assembly 10. If provided, the first yoke 22 can be coupled to the first shaft 24.

[0030] Main references Figure 2 , Figure 3 and Figure 5 , an example of the first axis 24 is shown. Figure 2 and Figure 3 as well as Figure 7 and Figure 8For clarity, the first shaft 24 is not shown in section. The first shaft 24 extends along a first axis 50 and is rotatable about the axis. For example, the first shaft 24 can be rotatably supported by one or more bearing assemblies 52. The first shaft 24 can be operably connected to the driven gear 32 and the second shaft 40 via the inter-axle differential unit 26. In at least one configuration and as Figure 5 As best shown, the first shaft 24 may include at least one spline, such as a first spline 60, a second spline 62, a third spline 64, or a combination thereof. A spline may be a tooth or a set of teeth that may be arranged about the first axis 50, may extend away from the first axis 50, may be disposed substantially parallel to the first axis 50, or a combination thereof. As used herein, the term "substantially parallel" means the same as parallel or very close to parallel, and includes features or axes that are parallel to each other within ±2°.

[0031] The first splines 60 engage the clutch collar 28 so that the clutch collar 28 can rotate with the first shaft 24 about the first axis 50. In addition, the first splines 60 allow the clutch collar 28 to move relative to the first shaft 24 in an axial direction or a direction extending along the first axis 50.

[0032] The second splines 62, if provided, can engage the first yoke 22. For example, the second splines 62 can mate or mesh with corresponding splines of the first yoke 22 so that the first yoke 22 can rotate with the first shaft 24 about the first axis 50.

[0033] The third spline 64 , if provided, may engage a cross-shaft 74 of the inter-axle differential unit 26 , as will be discussed in greater detail below.

[0034] Main references Figure 2 and Figure 3 , an example of an inter-axle differential unit 26 is shown. The inter-axle differential unit 26 is configured to accommodate or compensate for rotational speed differences between different drive axle assemblies, such as a speed difference between the axle assembly 10 and a second axle assembly connected in series with the axle assembly 10. As an example, the inter-axle differential unit 26 may operably connect the first shaft 24 and the second shaft 40 and may allow the first shaft 24 and the second shaft 40 to rotate at different speeds relative to each other under various operating conditions.

[0035] The inter-axle differential unit 26 may be provided in a variety of locations. Figure 2 and Figure 3In the embodiment of the present invention, the inter-axle differential unit 26 is disposed on an axle (such as the first axle 24) inside the housing assembly 20; however, it is contemplated that the inter-axle differential unit 26 can be disposed in other locations, such as closer to the second yoke 42 or with the second axle assembly. It is also contemplated that the inter-axle differential unit 26 can be disposed on another axle (such as the second axle 40). In some configurations, the inter-axle differential unit 26 includes a first side gear 70, a second side gear 72, a cross shaft 74, at least one pinion 76, and a cover 78.

[0036] Main references Figure 3 , Figure 5 and Figure 6 , the first side gear 70 can rotate about the first axis 50. In addition, the first side gear 70 can be selectively coupled to the first shaft 24. The first side gear 70 can be disposed proximate to the first shaft 24. For example, the first side gear 70 can extend along the first axis 50 and can have a central hole 80 that can receive or surround the first shaft 24 and optionally one or more bearing assemblies 82 that rotatably support the first side gear 70 on the first shaft 24. In some configurations, the first side gear 70 includes a pinion mating gear 84, a clutch collar mating gear 86, and a drive gear 88.

[0037] Main references Figure 3 and Figure 6 , the pinion mating gear 84 is configured to mate or mesh with at least one pinion gear 76. For example, the pinion mating gear 84 may include a set of teeth that may be arranged about the first axis 50 and may mate or mesh with teeth of at least one pinion gear 76. The set of teeth of the pinion mating gear 84 may extend inside the housing 78.

[0038] Main references Figure 3 and Figure 5 , the clutch collar mating gear 86 is configured to selectively engage with the clutch collar 28, as will be discussed in more detail below. The clutch collar mating gear 86 can have any suitable configuration. In some configurations, the clutch collar mating gear 86 can be configured as a face gear that can include a set of teeth that are disposed opposite the pinion mating gear 84 and axially away from the pinion mating gear 84 and protrude toward the clutch collar 28. In other configurations, the clutch collar mating gear 86 can be configured as an internal gear or spline that can include a set of teeth that can be disposed in the central bore 80 and can extend toward the first axis 50. In this configuration, the teeth of the clutch collar 28 can be inserted into the central bore 80 to selectively engage and mesh with the clutch collar mating gear 86.

[0039] The drive gear 88 is configured to mate or mesh with the driven gear 32. The drive gear 88 may include a set of teeth arranged about the first axis 50 and mate or mesh with the teeth of the driven gear 32. The set of teeth of the drive gear 88 may extend away from and away from the first axis 50.

[0040] Main references Figure 2 , Figure 3 and Figure 5 , the second side gear 72 can rotate with the second shaft 40 about the first axis 50. For example, the second side gear 72 can extend along the first axis 50 and can have a central hole that can receive or surround the end of the second shaft 40 and optionally the end of the first shaft 24. In some configurations, the central hole can also include splines or other fastening features, such as keys, pins, etc., that help inhibit the second side gear 72 from rotating relative to the second shaft 40 about the first axis 50. For example, the second side gear 72 and the second shaft 40 can have mating splines. For simplicity, the teeth of the second side gear 72 are not shown. Figure 5 Shown in.

[0041] Main references Figure 3 and Figure 5 , the cross shaft 74 can rotate with the first shaft 24 about the first axis 50. For example, the cross shaft 74 may include a central hole, which may include splines or other fastening features, such as keys, pins, etc., that help inhibit the cross shaft 74 from rotating relative to the first shaft 24 about the first axis 50. For example, the cross shaft 74 may have splines that cooperate with corresponding splines (such as the third spline 64) of the first shaft 24. The cross shaft 74 and the cover 78 are rotatable relative to each other. For example, the cross shaft 74 can be partially or completely received inside the cover 78 and can rotate relative to the cover 78 about the first axis 50 depending on the position of the clutch collar 28. The cross shaft 74 can also include one or more cross shaft shaft members 90, which can extend away from the central hole of the cross shaft 74. Figure 3 In FIG. 8 , portions of some cross-shaft shafts 90 are partially shown but not labeled due to the rotational position of the cross-shaft 74 .

[0042] One or more pinion gears 76 can rotate relative to the cross shaft 74. The pinion gears 76 are rotatably disposed on the cross shaft shaft 90 of the cross shaft 74. For example, the pinion gears 76 can define a hole that can receive or surround the corresponding cross shaft shaft 90 in a manner that allows the pinion gears 76 to rotate about the cross shaft shaft 90. The pinion gears 76 mesh with the first side gear 70 and the second side gear 72. For example, the pinion gears 76 can include teeth that can mesh or mate with the pinion gear mating gear 84 and can mesh or mate with teeth of the second side gear 72.

[0043] Main references Figure 3 , Figure 5 and Figure 6 , the housing 78 receives the components of the inter-axle differential unit 26. In some configurations, the housing 78 surrounds at least a portion of the first side gear 70, the second side gear 72, the cross shaft 74, the pinion gear 76, or a combination thereof. The housing 78 can be spaced apart from and separated from the first side gear 70 and the second side gear 72. In some configurations, the housing 78 can have a first housing end 100, a second housing end 102, a first opening 104, and a second opening 106.

[0044] Main references Figure 5 , the first housing end 100 faces the first side gear 70 . The first housing end 100 may extend around the first axis 50 and may surround the first opening 104 .

[0045] Main references Figure 6 The second housing end 102 is disposed at an end of the housing 78 opposite the first housing end 100. Thus, the second housing end 102 can face away from the first side gear 70. The second housing end 102 can extend around the first axis 50 and can surround the second opening 106.

[0046] Main references Figure 5 The first opening 104 extends around the first axis 50 and can be surrounded by the first housing end 100 . The first opening 104 can receive and surround the first side gear 70 .

[0047] Main references Figure 6 The second opening 106 is disposed at an end of the housing 78 opposite the first opening 104. The second opening 106 extends about the first axis 50 and may be surrounded by the second housing end 102. The second opening 106 may receive and may surround the second side gear 72.

[0048] Main references Figure 3 , Figure 5 and Figure 6, an example of a clutch collar 28 is shown. The clutch collar 28 is disposed on a shaft and can move relative to the shaft. For example, the clutch collar 28 can rotate with the shaft about a common axis and can move relative to the shaft along the axis to engage or disengage with another component. The clutch collar 28 can be configured to inhibit rotation of the component relative to the shaft when the clutch collar 28 engages such a component. Conversely, when the clutch collar 28 is disengaged from the component, the component can rotate relative to the shaft and the clutch collar 28. The clutch collar 28 will be primarily described in the context of the clutch collar 28 being rotatable with a corresponding shaft (such as the first shaft 24) about a first axis 50 and movable relative to the first shaft 24 along the first axis 50; however, it should be understood that the clutch collar 28 and the clutch collar shift mechanism 30 can be disposed on different shafts that can rotate about different axes. For example, the clutch collar 28 and the clutch collar shift mechanism 30 can be disposed along a second axis 110, and the second shaft 40 can rotate about the second axis to selectively couple the driven gear 32 to the second shaft 40. It is also contemplated that the clutch collar 28 and clutch collar shift mechanism 30 can be configured to couple and decouple rotatable components (such as gears) with corresponding shafts having a common axis of rotation. In this way, the clutch collar 28 and clutch collar shift mechanism 30 can be provided with a transmission or the like.

[0049] In some configurations, such as those in which the clutch collar 28 is associated with the inter-axle differential unit 26, the clutch collar 28 is movable along the first axis 50 to engage or disengage with the first side gear 70 of the inter-axle differential unit 26 (such as the clutch collar mating gear 86 of the first side gear 70), thereby locking or unlocking the inter-axle differential unit 26, as will be discussed in more detail below.

[0050] The clutch collar 28 can be provided in a variety of configurations. In some configurations, the clutch collar 28 is generally annular and includes a clutch collar bore 120, clutch collar splines 122, and a clutch collar gear 124. The clutch collar 28 can also include an outer collar side 128 and an end wall 126.

[0051] The clutch collar bore 120 extends about a corresponding axis, such as the first axis 50. The clutch collar bore 120 receives a shaft, such as the first shaft 24.

[0052] The clutch collar splines 122 are disposed in the clutch collar bore 120. The clutch collar splines 122 may include a plurality of spline teeth that may extend toward the first axis 50 and may mate or mesh with the teeth of the first splines 60 of the first shaft 24. In this manner, the clutch collar 28 may rotate with the first shaft 24 about the first axis 50 and may move along the first axis 50 or may move in an axial direction relative to the first shaft 24.

[0053] The clutch collar gear 124 is configured to mesh or cooperate with teeth of another component, such as the teeth of the clutch collar mating gear 86 of the first side gear 70. In this configuration, the clutch collar gear 124 may include a set of teeth arranged about the first axis 50 and may face and extend toward the inter-axle differential unit 26.

[0054] The clutch collar 28 is movable along an axis between a first position and a second position.

[0055] refer to Figure 3 and Figure 7 , an example of the clutch collar 28 in a first position is shown. In the first position, the clutch collar 28 can be spaced apart from and not engaged with a corresponding component (e.g., a gear, such as the first side gear 70). For example, when the clutch collar 28 is in the first position, the clutch collar gear 124 can be spaced apart from and not engaged or meshed with the teeth of the clutch collar mating gear 86. As such, the first side gear 70 can rotate relative to the first shaft 24 and the clutch collar 28 about the first axis 50. In this configuration, the inter-axle differential unit 26 is unlocked, and the first shaft 24 and the second shaft 40 can rotate relative to each other about the first axis 50.

[0056] refer to Figure 4 and Figure 8 , shows an example of the clutch collar 28 in a second position. In the second position, the clutch collar 28 can be moved into contact or engagement with a corresponding component (such as a gear, such as the first side gear 70). For example, when the clutch collar 28 is in the second position, the clutch collar gear 124 can engage or mesh with the teeth of the clutch collar mating gear 86. In this way, the first shaft 24, the clutch collar 28, and the first side gear 70 can rotate together about the first axis 50. This in turn inhibits the rotation of the pinion gear 76 because the rotation of the cross shaft 74 relative to the first shaft 24 is inhibited. Therefore, the inter-axle differential unit 26 is locked, and the first shaft 24 and the second shaft 40 can rotate together about the first axis 50.

[0057] Main references Figure 3 and Figure 5, an end wall 126 can be disposed at an end of the clutch collar 28 that is disposed opposite the clutch collar gear 124. The end wall 126 can extend toward the first axis 50 and can be spaced apart from the first shaft 24. In some configurations, the end wall 126 extends further toward the first axis 50 than the clutch collar splines 122. The end wall 126 can contact or engage a biasing member 146 that applies a biasing force to the clutch collar 28, as will be discussed in more detail below.

[0058] refer to Figure 3 and Figure 5 , the outer collar side 128 faces away from the first axis 50. The outer collar side 128 can be provided in various configurations. Figures 3 to 6 In the illustrated configuration, the outer collar side 128 engages the bearing assembly 144. Figures 7 to 9 In the configuration shown, the outer collar side 128 may not engage the bearing assembly. In some configurations, the outer collar side 128 or a portion thereof is disposed at an oblique angle relative to the first axis 50. An example of such a configuration is shown in FIG. Figure 3 and Figure 4 In some configurations, the outer collar side 128 is not disposed at an oblique angle relative to the first axis 50. For example, the outer collar side 128 can be disposed substantially parallel to the first axis 50, as in Figure 7 and Figure 8 as shown in the example.

[0059] Main references Figure 3 The clutch collar shift mechanism 30 is configured to actuate the clutch collar 28 along an axis relative to a shaft on which the clutch collar is disposed. In some configurations, the clutch collar shift mechanism 30 includes an outer housing 140, a piston 142, a bearing assembly 144, and a biasing member 146. The clutch collar shift mechanism 30 may also include a first seal 148 and a second seal 150.

[0060] Main references Figure 3 , Figure 5 and Figure 6 , the outer housing 140 is configured to receive components of the clutch collar shift mechanism 30. The outer housing 140 can be fixedly positioned relative to the housing assembly 20 or can be a part of the housing assembly 20. In some configurations, the outer housing 140 can be fixedly mounted to the differential carrier of the housing assembly 20 by one or more fasteners (such as bolts). In some configurations, the outer housing 140 can surround and engage a bearing assembly that rotatably supports a corresponding shaft, such as the bearing assembly 52 that rotatably supports the first shaft 24. In some configurations, the outer housing 140 defines an opening 160 and a fluid passage 162.

[0061] The opening 160 is configured to receive the clutch collar shift mechanism 30. The opening 160 can be configured as a through hole that can receive components of the clutch collar shift mechanism 30, such as the piston 142, the bearing assembly 144, and the biasing member 146, or a combination thereof. The opening 160 can also receive a shaft, such as the first shaft 24, and extend or surround the corresponding axis, such as the first axis 50. In some configurations, the opening 160 can also receive a bearing assembly that rotatably supports the shaft, such as the bearing assembly 52. ​​In this way, the outer housing 140 can surround the first shaft 24, the first axis 50, the bearing assembly 52, the piston 142, the bearing assembly 144, the biasing member 146, or a combination thereof.

[0062] The opening 160 can have any suitable configuration. In the illustrated configuration, the opening 160 is defined by a plurality of surfaces facing a corresponding axis, such as the first axis 50. For example, the opening 160 can be at least partially defined by a first inner surface 170, a second inner surface 172, and a stepped surface 174, the first inner surface, the second inner surface, and the stepped surface being referred to as Figure 3 Best shown.

[0063] The first inner surface 170 faces the first axis 50. In some configurations, the first inner surface 170 extends from an end of the outer housing 140 that faces the inter-axle differential unit 26. The first inner surface 170 may surround the first axis 50. The first inner surface 170 may be disposed radially relative to the first axis 50.

[0064] The second inner surface 172 faces the first axis 50. The second inner surface 172 can surround the first axis 50. The second inner surface 172 can be disposed radially relative to the first axis 50. In some configurations, the second inner surface 172 can be disposed closer to the first axis 50 than the first inner surface 170.

[0065] The step surface 174 can extend from the first inner surface 170 to the second inner surface 172. For example, the step surface 174 can extend from the end of the first inner surface 170 to the end of the second inner surface 172. In some configurations, the step surface 174 can be disposed substantially perpendicular to the first axis 50. The term "substantially perpendicular" is used herein to refer to features or axes that are the same as or very close to perpendicular, and includes features that are perpendicular to each other within ±3°.

[0066] The fluid passage 162 extends through the outer housing 140. The fluid passage 162 is configured to supply a pressurized fluid, such as a gas or a liquid, that actuates the piston 142, as will be discussed in more detail below. In some configurations, the fluid passage 162 is configured as a through hole extending from an outside of the outer housing 140 to an inside of the outer housing 140 disposed adjacent the piston 142. The outside of the outer housing 140 may or may not be the outside of the axle assembly 10. The fluid passage 162 may include a first port 180 and a second port 182.

[0067] The first port 180 can be disposed at a first end of the fluid passage 162. The first port 180 can be fluidly connected to a pressurized gas source 184, an example of which is shown in FIG. Figure 1 The first port 180 may be fluidly connected to a source of pressurized gas via a conduit (eg, a hose, a tube, etc.).

[0068] The second port 182 may be disposed at a second end of the fluid passage 162 disposed opposite the first end. The second port 182 may be disposed proximate to the piston 142 and to a cavity or chamber provided between the outer housing 140 and the piston 142. In the illustrated configuration, the second port 182 extends from the stepped surface 174.

[0069] Main references Figure 3 and Figure 5 , the piston 142 is configured to actuate the clutch collar 28. The piston 142 is movable relative to the outer housing 140. For example, the piston 142 may be received within the opening 160 of the outer housing 140 and may be movable relative to the outer housing 140 in an axial direction (e.g., in a direction extending along the first axis 50). The piston 142 may not be rotatable about a corresponding axis (e.g., the first axis 50). As such, the clutch collar 28 may be rotatable relative to the piston 142 about the corresponding axis.

[0070] The outer housing 140 surrounds a piston 142. The piston 142 may surround the clutch collar 28, the bearing assembly 144, or both. The piston 142 may be spaced apart from the clutch collar 28 and may not contact the clutch collar to allow the clutch collar 28 to rotate relative to the piston 142 about a corresponding axis, such as the first axis 50.

[0071] The piston 142 can have any suitable configuration. In at least one configuration, the piston 142 has an outer piston side 190 and an inner piston side 192, the outer piston side and the inner piston side are referred to as Figure 5 Best shown.

[0072] The outer piston side 190 may face away from the corresponding axis and may face the outer housing 140. In some configurations, the outer piston side 190 may include a first outer piston surface 200, a second outer piston surface 202, and a piston step surface 204. Figure 3 Best shown in .

[0073] The first outer piston surface 200 faces away from the first axis 50. The first outer piston surface 200 can face the first inner surface 170 of the outer housing 140. In this way, the first inner surface 170 can surround at least a portion of the first outer piston surface 200. The first outer piston surface 200 can be aligned with or disposed substantially parallel to the first inner surface 170.

[0074] The second outer piston surface 202 faces away from the first axis 50. The second outer piston surface 202 can face the second inner surface 172 of the outer housing 140. In this way, the second inner surface 172 can surround at least a portion of the second outer piston surface 202. The second outer piston surface 202 can be aligned with or disposed substantially parallel to the second inner surface 172. The second outer piston surface 202 can be disposed closer to the first axis 50 than the first outer piston surface 200.

[0075] The piston step surface 204 extends between the first outer piston surface 200 and the second outer piston surface 202. For example, the piston step surface 204 can extend from the end of the first outer piston surface 200 to the end of the second outer piston surface 202. In some configurations, the piston step surface 204 can be aligned with or substantially parallel to the step surface 174 of the outer housing 140. As an example, the piston step surface 204 can be disposed substantially perpendicular to the first axis 50.

[0076] The inner piston side 192 is disposed opposite the outer piston side 190. As such, the inner piston side 192 faces the corresponding axis and the clutch collar 28. The inner piston side 192 may surround the outer collar side 128 of the clutch collar 28. Additionally, the inner piston side 192 may be spaced apart from the outer collar side 128 of the clutch collar 28 to allow the clutch collar 28 to rotate more freely relative to the piston 142. The inner piston side 192 may be provided in a variety of configurations. Figure 3 and Figure 4 In the illustrated configuration, a portion of the inner piston side 192 is disposed at an oblique angle relative to the first axis 50. In some configurations, the bearing assembly 144 can extend from the inner piston side 192. Figure 7 and Figure 8 In the configuration shown, the bearing assembly 144 may not extend from the inner piston side 192. Figures 2 to 4 , Figure 7 and Figure 8In the figure, for the sake of clarity, the bearing assembly 144 is not shown in section.

[0077] Main references Figure 5 and Fig. 9 In some configurations, the piston 142 can include at least one slot 194. The slot 194 can be a closed slot or an open-ended slot that can extend from an end of the piston 142 (such as an end facing the inter-axle differential unit 26). The slot 194 can receive a pin 196 extending from the outer housing 140. For example, the pin 196 can extend from the outer housing 140 toward a corresponding axis (such as the first axis 50).

[0078] The pin 196 and the slot 142 cooperate to inhibit the piston 142 from rotating about a corresponding axis (eg, the first axis 50 ).

[0079] Alternatively or additionally, the pin 196 may engage the piston 142 in the slot 142 to limit movement of the piston 142 relative to the outer housing 140 along the corresponding axis. Figure 7 and Figure 8 An example of this is shown in Figure 8 , the pin 196 can engage the closed end of the slot 142 (i.e., the left end of the slot 142 from the perspective shown), which is disposed farthest from the end of the piston 142 facing the inter-axle differential unit 26, to limit axial movement of the piston 142 toward the inter-axle differential unit 26 when the piston 142 is extended and the clutch collar 28 is in the second position. Figure 7 When the piston 142 is Figure 7 When retracted as shown, the pin 196 can be spaced apart from the closed end of the slot 142 and disposed closer to the other end of the slot 142. It is also contemplated that the positioning of the slot and the pin can be reversed, and in other configurations, the pin 196 can be fixedly disposed on the piston 142 and extend into the slot in the outer housing 140. Figures 3 to 6 The configuration in FIG. 1 provides at least one pin 196 and slot 142, but for clarity, in FIG. Figure 3 and Figure 4 Not shown.

[0080] Main references Figure 3 and Figure 5 , the bearing assembly 144 facilitates rotation of the clutch collar 28 relative to the piston 142. The bearing assembly 144 extends between the clutch collar 28 and the piston 142. For example, the bearing assembly 144 can extend from the clutch collar 28 to the piston 142 and can engage or contact the clutch collar 28 and the piston 142. In some configurations, the bearing assembly 144 surrounds the clutch collar 28. The piston 142 can surround the bearing assembly 144.

[0081] The bearing assembly 144 may be of any suitable type. For example, the bearing assembly 144 may be a roller bearing assembly including a plurality of bearing elements that may be disposed between an inner race and an outer race.

[0082] The bearing assembly 144 is movable along the corresponding axis with the clutch collar 28 and the piston 142. The bearing assembly 144 may be disposed in any suitable position.

[0083] exist Figures 3 to 6 In the illustrated configuration, the bearing assembly 144 extends between the inner piston side 192 of the piston 142 and the outer collar side 128 of the clutch collar 28. For example, the bearing assembly 144 can extend from the inner piston side 192 to the outer collar side 128. In some configurations, the inner piston side 192 and the outer collar side 128 can be provided with corresponding recesses or recesses that can receive the bearing assembly 144 and help inhibit axial movement of the bearing assembly. For example, the inner piston side 192 can have a recess or recess that can engage the outer race of the bearing assembly 144 and inhibit axial movement of the outer race in a direction extending away from the inter-axle differential unit 26 or in a direction extending to the left from the perspective shown. Similarly, the outer collar side 128 can have a recess or recess that can engage the inner race of the bearing assembly 144 and inhibit axial movement of the inner race in a direction extending toward the inter-axle differential unit 26 or in a direction extending to the right from the perspective shown. It is also contemplated that the notch or recess may be omitted from the inner piston side 192 , the outer ring side 128 , or both, and that axial movement of the race of the bearing assembly 144 may be inhibited by a securing feature such as a snap ring or the like.

[0084] exist Figures 7 to 9 In the illustrated configuration, the bearing assembly 144 is configured as a thrust bearing extending in an axial direction between the clutch collar 28 and the piston 142. For example, the bearing assembly 144 may extend between the clutch collar side 210 of the clutch collar 28 and the piston wall 212 of the piston 142, as shown in FIG. Figure 7 The clutch collar side 210 is disposed opposite the clutch collar gear 124 and may be disposed substantially perpendicular to the first axis 50. The piston wall 212 projects toward the first axis 50, may be disposed substantially perpendicular to the first axis 50, and may surround a portion of the clutch collar 28.

[0085] Main references Figure 3 and Figure 5, the biasing member 146 applies a biasing force that urges the components of the clutch collar shift mechanism 30 to move along the corresponding axis. For example, the biasing member 146 can apply a biasing force that urges the clutch collar 28, the piston 142, and the bearing assembly 144 to move together along the first axis 50. The biasing member 146 can extend in a direction away from the first side gear 70 of the inter-axle differential unit 26 or from the Figure 3 , Figure 4 , Figure 7 and Figure 8 In this way, the biasing member 146 can drive the clutch collar 28 along the first axis 50 from Figure 4 and Figure 8 The second position shown is Figure 3 and Figure 7 The first position shown is moved.

[0086] The biasing member 146 can have any suitable configuration. For example, the biasing member 146 can be configured as a resilient member or one or more springs, such as a coil spring, a wave spring, etc. In at least one configuration, the biasing member 146 can extend axially between the clutch collar 28 and the corresponding shaft. For example, the biasing member 146 can extend from the end wall 126 of the clutch collar 28 to the first shaft 24 or the portion of the first shaft from which the first spline 60 can extend. In some configurations, the biasing member 146 can surround the corresponding shaft and axis, such as the first shaft 24 and the first axis 50; however, it is contemplated that in a plurality of different configurations, the biasing member 146 may not surround these features, such as when multiple biasing members are provided around an axis, arranged at different angular positions relative to the axis (such as the first axis 50). The biasing member 146 can be surrounded by the clutch collar 28, the piston 142, the bearing assembly 144, or a combination thereof.

[0087] Main references Figure 3 and Figure 5 , the first seal 148 can extend between the outer housing 140 and the piston 142. For example, the first seal 148 can extend between the first inner surface 170 of the outer housing 140 and the first outer piston surface 200. In some configurations, the first seal 148 can be received in a groove in the first outer piston surface 200 and extend to the first inner surface 170. In this configuration, the first seal 148 can move with the piston 142. It is also conceivable that this configuration can be reversed and the first seal 148 can be received in a groove in the first inner surface 170. The first seal 148 can have any suitable configuration. For example, the first seal 148 can be configured as an O-ring that can surround the piston 142 and a corresponding axis (such as the first axis 50).

[0088] The second seal 150 may also extend between the outer housing 140 and the piston 142. For example, the second seal 150 may extend between the second inner surface 172 of the outer housing 140 and the second outer piston surface 202. In some configurations, the second seal 150 may be received in a groove in the second outer piston surface 202 and extend to the second inner surface 172. In this configuration, the second seal 150 may move with the piston 142. It is also conceivable that this configuration may be reversed and the second seal 150 may be received in a groove in the second inner surface 172. The second seal 150 may have any suitable configuration. For example, the second seal 150 may be configured as an O-ring that may surround the piston 142 and a corresponding axis (such as the first axis 50). The second seal 150 may be disposed closer to the first axis 50 than the first seal 148. The second port 182 of the fluid passage 162 may be axially positioned between the first seal 148 and the second seal 150.

[0089] Main references Figure 4 and Figure 8 , a cavity 220 may be provided between the outer housing 140 and the piston 142. The outer housing 140, the piston 142, the first seal 148, and the second seal 150 may cooperate to define the cavity 220.

[0090] When pressurized fluid is provided to the cavity 220, the clutch collar 28 can move from the first position to the second position along the corresponding axis. The pressurized fluid can be provided to the cavity 220 via the fluid passage 162 to actuate the piston 142 along the corresponding axis. For example, the pressurized fluid provided to the cavity 220 via the fluid passage 162 applies a force to the piston 142 and causes the piston 142 to move from the first position to the second position along the first axis 50. Figure 3 and Figure 7 The first position shown moves to Figure 4 and Figure 8 The second position shown. The pressurized fluid may also be exhausted from the cavity 220 via the fluid passage 162; however, it is also contemplated that separate fluid passages may be provided, wherein at least one fluid passage provides pressurized fluid to the cavity 220 and at least one different fluid passage exhausts the pressurized fluid from the cavity 220. Expelling the pressurized fluid from the cavity 220 reduces the force exerted by the fluid on the piston 142 and allows the piston 142 to move along the axis from the second position to the first position under the biasing force exerted by the biasing member 146. Thus, the volume of the cavity 220 may be greater in the second position than in the first position.

[0091] refer to Figure 2, the driven gear 32 can rotate about the second axis 110. For example, the drive pinion 34 can be received in the central hole of the driven gear 32, and the driven gear 32 can be fixedly disposed on the drive pinion 34 or can be coupled to the drive pinion 34 so that the driven gear 32 and the drive pinion 34 can rotate together about the second axis 110. The driven gear 32 can include a plurality of teeth that can be generally arranged around the outer diameter of the driven gear 32 and can cooperate or mesh with the teeth of the drive gear 88. The second axis 110 can be arranged to be substantially parallel to the first axis 50.

[0092] The drive pinion 34 can help operatively connect the torque source to the differential assembly 36. The drive pinion 34 can be spaced apart from the first shaft 24 and can be configured to rotate about an axis, such as the second axis 110. The drive pinion 34 can rotate with the driven gear 32. A gear portion can be provided at an end of the drive pinion 34.

[0093] The differential assembly 36 can be at least partially received in the housing assembly 20. The differential assembly 36 can rotate about an axis (such as a differential axis 230) that can be arranged to be substantially perpendicular to the second axis 110. The differential assembly 36 can transfer torque to the half shaft 38 and the wheel. For example, the differential assembly 36 can be operably connected to the half shaft 38 and can allow the half shaft 38 to rotate relative to each other at different rotational speeds in a manner known to those skilled in the art. The differential assembly 36 has a ring gear 240, which can have teeth that can cooperate or mesh with the teeth of the gear portion of the drive pinion 34. Accordingly, the differential assembly 36 can receive torque from the drive pinion 34 via the ring gear 240 and transfer the torque to the half shaft 38.

[0094] refer to Figure 1 and Figure 2 , the half shafts 38 can transfer torque from the differential assembly 36 to the corresponding wheel hub and wheel. The half shafts 38 can extend along an axis and can rotate about the axis, which can be the same as or different from the differential axis 230. Each half shaft 38 can have a first end and a second end. The first end can be operably connected to the differential assembly 36. The second end can be arranged opposite to the first end and can be operably connected to the wheel.

[0095] refer to Figure 2 , the second shaft 40 can extend along the first axis 50 and can rotate about the axis. For example, the second shaft 40 can be supported by one or more bearings, which can be disposed on the housing assembly 20. The second shaft 40 can be coupled to the inter-axle differential unit 26. For example, the second shaft 40 can be fixedly coupled to the second side gear 72.

[0096] refer to Figure 1 , the second yoke 42 (if provided) can facilitate coupling the axle assembly 10 to another axle assembly. For example, the second yoke 42 can be fixedly coupled to the second shaft 40 in any suitable manner (such as using mating splines and fasteners such as nuts). The second yoke 42 can be operably connected to the second axle assembly in any suitable manner (such as via a drive shaft).

[0097] The axle assembly as described above can allow the axle assembly to be provided with a clutch collar shift mechanism that is more compact and can have fewer parts than other designs (such as designs that use a shift fork that connects the clutch collar to a corresponding actuator that can move along an axis different from the clutch collar). The clutch collar shift mechanism of the present invention allows a piston to be provided that surrounds the shift collar and is coaxially arranged with the shift collar to further reduce packaging space requirements and reduce the complexity of the shift mechanism. The assembly of the shift mechanism can be easier and faster than designs that use a shift fork and may have a spring that needs to be compressed with an external tool to allow the shift fork to be installed in the desired position. The shift mechanism of the present invention can be easier to repair than previous designs. The shift mechanism of the present invention can also be lighter in weight, which can help reduce the weight of the axle assembly and improve fuel economy. The present invention can allow the shift mechanism to be encapsulated in an outer housing that can provide improved sealing through a pair of O-rings and can reduce or eliminate the requirements for sealants between associated components.

[0098] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the present invention. Rather, the words used in this specification are descriptive rather than restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of the present invention. Additionally, the features of various implemented embodiments may be combined to form other embodiments of the present invention.

Claims

1. A vehicle axle assembly, comprising: a shaft, the shaft being rotatable about an axis; a clutch collar disposed on the shaft and movable relative to the shaft along the axis; a piston, the piston surrounding the clutch collar; as well as A bearing assembly extends between the piston and the clutch collar and facilitates rotation of the clutch collar relative to the piston.

2. The axle assembly of claim 1 , further comprising an outer housing surrounding the piston, wherein the outer housing and the piston cooperate to at least partially define a cavity therebetween, wherein the clutch collar is movable along the axis from a first position to a second position when pressurized fluid is provided to the cavity.

3. The axle assembly of claim 2, further comprising an inter-axle differential unit disposed on the shaft, the inter-axle differential unit comprising a first side gear, wherein when the clutch collar is in the first position, the first side gear is rotatable relative to the first shaft about the first axis, and when the clutch collar is in the second position, the first shaft, the clutch collar, and the first side gear are rotatable together about the first axis.

4. The axle assembly of claim 2, wherein: The outer housing includes a fluid passage extending from the cavity through the outer housing, wherein the pressurized fluid is provided to the cavity via the fluid passage.

5. The axle assembly of claim 2, further comprising a first seal and a second seal surrounding the axis and the piston, wherein the first seal and the second seal engage the outer housing and cooperate with the outer housing and the piston to define the cavity.

6. The axle assembly of claim 5, wherein: The second seal is disposed closer to the axis than the first seal.

7. The axle assembly of claim 5, wherein: The outer housing includes a fluid passage having a port disposed adjacent the cavity, wherein the port is axially positioned between the first seal and the second seal.

8. The axle assembly of claim 1 further comprising an outer housing surrounding said piston and said clutch collar.

9. The axle assembly of claim 1, wherein: The piston surrounds the bearing assembly.

10. The axle assembly of claim 1, wherein: The bearing assembly surrounds the clutch collar.

11. The axle assembly of claim 1, wherein: The bearing assembly is movable along the axis with the clutch collar and the piston.

12. The axle assembly of claim 1, wherein: The piston is spaced apart from and does not contact the clutch collar.

13. The axle assembly of claim 1 further comprising a biasing member urging the clutch collar and the piston to move along the axis from a second position to a first position, wherein the clutch collar couples a component to the shaft when in the second position and does not couple the component to the shaft when in the first position.

14. The axle assembly of claim 13, wherein: The biasing member extends from the shaft to the clutch collar.

15. The axle assembly of claim 13, wherein: The biasing member is surrounded by the clutch collar.

16. The axle assembly of claim 13, wherein: The biasing member is surrounded by the piston.

17. The axle assembly of claim 1 further comprising an outer housing surrounding the piston and a pin extending from the outer housing toward the axis and engageable with the piston to limit movement of the piston relative to the outer housing along the axis.

18. The axle assembly of claim 17, wherein: The piston has a slot, and the pin is received in the slot.

19. The axle assembly of claim 1, wherein: The clutch collar has an outer collar side facing away from the axis, and the piston has an inner piston side surrounding the outer collar side, wherein the bearing assembly extends from the inner piston side and the outer collar side.

20. The axle assembly of claim 19, wherein: The inner piston side and the outer ring side are arranged at an inclined angle relative to the axis.

Images