WO2016040831A1

WO2016040831A1 - Axle wheel end axial thrust assembly

Info

Publication number: WO2016040831A1
Application number: PCT/US2015/049735
Authority: WO
Inventors: Scott ABRAHAMSON
Original assignee: Koyo Bearings North America Llc
Priority date: 2014-09-11
Filing date: 2015-09-11
Publication date: 2016-03-17

Abstract

An axle assembly of a vehicle including a differential assembly, a first axle tube defining an axle bore extending outwardly from a first side of the differential assembly, a first axle shaft rotatably received in the first axle tube and defining an annular groove in its outer surface, and an annular housing that is disposed within the axle bore of the first axle tube and is non-rotatably fixed to the axle tube, the annular housing defining an annular groove in which at least one C-ring is retractably received, wherein the at least one C-ring is selectively insertable into and out of the annular groove of the axle shaft.

Description

NAME OF INVENTION

AXLE WHEEL END AXIAL THRUST ASSEMBLY

FIELD OF THE INVENTION

[0001] The present disclosure relates generally to solid axle assemblies for vehicles and, more specifically, to bearing assemblies that are utilized on the wheel end sections of such solid axle assemblies.

BACKGROUND

[0002] Salisbury solid axles are often used in passenger trucks and sport utility vehicles. Salisbury axles are unique in the fact that the axle transmits driving torque to the wheel as well as carries and transmits both radial and axial thrust loads.

[0003] As shown in Figure 1 , many existing wheel end bearings 10 for use with solid axles include an outer cup 11 that is press-fit into the corresponding axle tube 12 to maintain location and define an outer raceway for the corresponding rollers 13. No additional retention features are required for this type of wheel end bearing 10 in that the bearing only handles radial loads. Lubrication for wheel end bearing 10 is provided by the same oil sump that provides lubrication to the differential gears 15 (Figure 2) that are disposed at the center section of the axle assembly. To maintain lubrication, an oil seal 14 is press-fitted outboard of the wheel end bearing in axle tube 12.

[0004] Radial wheel end loads are handled primarily at wheel end bearing 10, whereas axial loads are not. Rather, as best seen in Figures 2 through 4, axial loads are transmitted along axle shaft 16. Typically, "C Locks" 18 are utilized to resist outward axial loading and a cross shaft 20 disposed between the opposing axles in a housing 25 of differential 17 absorbs inward axial loading. A typical C Lock includes a heavy annular lock ring 19 received in an annular groove 21 formed on the inboard end of a corresponding axle shaft 16. In the fully assembled configuration (Figure 3), annular lock ring 19 is further received in an annular recess 23 formed in an end face of a corresponding differential gear 15. During normal operations, inward axial loading has a higher magnitude than outward axial loading due to vehicle dynamics during cornering. When outward axial load on axle shaft 16 occurs, axle shaft 16 attempts to move outwardly from axle tube 12, which causes annular lock ring 19 of the corresponding C Lock 18 to push on the corresponding differential side gear 15.

Ultimately, the outward axial load is dispersed through differential carrier bearings 24 to housing 25 of the differential, as shown in Figure 4.

[0005] When inward axial loading is generated from vehicle cornering, an end face 27 of axle shaft 16 thrusts against differential cross shaft 20, as best seen in Figure 2. In turn, the inward axial loading is transmitted through differential carrier bearings 24, as shown in Figure 4.

[0006] The present invention recognizes and addresses considerations of prior art constructions and methods.

SUMMARY

[0007] One embodiment of an axle assembly of a vehicle includes a differential assembly, a first axle tube extending outwardly from a first side of the differential assembly, the first axle tube including a proximal end adjacent the differential assembly, an opposite distal end, and an axle bore extending therebetween, a first axle shaft rotatably received in the first axle tube, the first axle shaft including a proximal end disposed in the differential assembly, an opposite distal end extending outwardly from the distal end of the first axle shaft, and an annular groove disposed in its outer surface, and an annular housing that is disposed within the axle bore of the first axle tube and is non-rotatably fixed to the axle tube, the annular housing defining an annular groove in which at least one C-ring is retractably received, wherein the at least one C- ring is selectively insertable into and out of the annular groove of the axle shaft.

[0008] Another embodiment of an axle assembly of a vehicle includes a differential assembly, a first axle tube extending outwardly from a first side of the differential assembly, the first axle tube including a proximal end adjacent the differential assembly, an opposite distal end, and an axle bore extending therebetween, a first axle shaft rotatably received in the first axle tube, the first axle shaft including a proximal end disposed in the differential assembly, an opposite distal end extending outwardly from the distal end of the first axle shaft, and an annular groove disposed in its outer surface, and an annular housing that is disposed within the axle bore of the first axle tube, the annular housing defining an annular groove in which at least one C-ring is retractably received, wherein the at least one C-ring is selectively insertable into and out of the annular groove of the axle shaft.

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which: [0011] Figure 1 is a partial cross-sectional view of a wheel end section of a prior art solid axle assembly;

[0012] Figure 2 is a partial perspective view of the prior art axle shaft shown in Figure 1 and a corresponding differential;

[0013] Figure 3 is a partial perspective view of the prior art axle shaft and differential shown in Figure 2, including a cross shaft of the differential;

[0014] Figure 4 is a cut away side view of the prior art axle shaft and differential shown in Figure 2;

[0015] Figure 5 is a partial cross-sectional view of a wheel end section of a solid axle assembly including an axial thrust assembly in accordance with an embodiment of the present invention; and

[0016] Figure 6 is an exploded perspective view of the axial thrust assembly shown in Figure 5.

[0017] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0019] Referring now to Figures 5 and 6, a wheel end axial thrust assembly 100 for use with a solid vehicle axle in accordance with an embodiment of the present disclosure includes a thrust component including an annular housing 102 in which a pair of C-rings 130 is received, a radial bearing assembly 180, an annular sleeve 170 disposed therebetween, and a snap ring 190 received in an annular groove 168 of the corresponding axle tube 160, outboard of radial bearing assembly 180. Axial thrust assembly 100 is disposed in the wheel end of a

corresponding axle tube 160 about the wheel end of an axle shaft 150, as discussed in greater detail below.

[0020] Annular housing 102 of the axial thrust component includes a cylindrical outer wall 105 having a cylindrical outer surface, and a pair of annular sidewalls 106 depending radially- inwardly therefrom, which define an annular groove 108 therebetween. As shown, annular groove 108 is configured to slidably receive a pair of C-rings 130 therein. Each C-ring 130 includes a semi-cylindrical inner surface 132, a semi-cylindrical outer surface 134, and a pair of sidewalls 140 extending therebetween, wherein sidewalls 140 are transverse to a

longitudinal center axis of axle shaft 150. As best seen in Figure 5, each C-ring 130 includes a threaded bore 136 that allows C-ring 130 to be engaged by a correspondingly threaded stem 114 of a cap screw 112 so that C-rings 130 may be retracted into annular groove 108 of annular housing 102. C-rings 130 are retracted into annular housing 102 to allow the corresponding axle shaft 150 to be inserted and withdrawn from the central bore of annular housing 102, such as during assembly and disassembly of the wheel end assembly. Note, in alternate embodiments, rather than two 180° C-rings 130, various numbers of C-rings 130 may be utilized, such as three (each spanning 120°), four (each spanning 90°), etc.

[0021] Both annular housing 102 and axle tube 160 include pairs of access apertures 110 and 170, respectively, to allow cap screws 112 to pass therethrough and engage C-rings 130. Preferably, access apertures 110 of annular housing 102 are smooth-walled bores whereas access apertures 170 of axle tube 160 are bores that are threaded correspondingly to cap screws 112. Preferably, a coil spring 120 is disposed between each C-ring 130 and annular housing 102. Each spring 120 is preferably disposed about threaded stem 114 of a corresponding set screw 112 to maintain each spring 120 in the desired positions. Additionally, each C-ring 130 may define an annular recess 138 (Figure 5) in its outer cylindrical surface 134 that receives one end of a corresponding spring 120, thereby helping to maintain its position.

[0022] As best seen in Figure 5, annular housing 102 is preferably received in a light press-fit in a cylindrical recess 162 that is defined by the wheel end of axle tube 160, allowing it to move slightly in the axial direction as forces act upon axle shaft 150. The extent of travel is limited by the tolerances between the outer diameter of cap screws 112 and inner diameter of access bores 110. Cylindrical recess 162 has a slightly greater diameter than does the remainder of the axle tube's bore 164 so that an annular ledge 166 is defined at their juncture. Annular ledge 166 is transverse to the longitudinal center axis of axle tube 160 and configured to abut the inboard annular sidewall 106 of annular housing 102. As such, annular ledge 166 helps position annular housing 102 within axle tube 160 during installation and allows annular housing 102 to transfer inward axle thrust forces on axle shaft 150 to axle tube 160, if desired. Note, however, in alternative embodiments, annular housing 102 may simply be received in bore 164 of a corresponding axle tube 160 with further inward motion of axle shaft 150 being prevented by way of the corresponding differential cross shaft 20 (Figure 3). Note, if the press-fit between annular housing 102 and cylindrical recess 162 of axle tube 160 is tight enough, cap screws 112 are not required to prevent the rotation of annular housing 102 within axle tube 160 that may occur due to friction between C-rings 130 and axle shaft 150.

However, cap screws 112 are preferably utilized so that a light press-fit, or slip fit, may be used to mount annular housing 102 in axle tube 160.

[0023] Outer cup 182 of radial bearing assembly 180 defines a cylindrical outer race 184 for needle rollers 192. A first annular flange 186 and a second annular flange 188 extend radially-inwardly from opposite ends of outer race 184. Outer cup 182 is preferably a machined and ground component made from a carburized grade of steel to enhance control of the press-fit, bearing clearances, and increase allowable hoop stresses. As best seen in Figure 5, outer cup 182 is preferably received in cylindrical recess 162 of axle tube 160 in a press-fit, outboard of annular housing 102. Outer cup 182 is press-fit in cylindrical recess 162 to assist in handling outward axial thrust forces, as is annular sleeve 170 which his disposed between annular housing 102 and radial bearing assembly 180. As shown, a first end 172 of annular sleeve 170 abuts annular housing 102, whereas a second end of annular sleeve 170 abuts outer cup 182 of the radial baring. As such, annular sleeve 170 also assists in handling outward axial thrust forces acting on axle shaft 150.

[0024] Note, in some embodiments, outward axial thrust forces are handled solely by the press-fit of annular sleeve 170 and outer cup 130 in axle tube 160. Note, however, in the present embodiment, a snap ring 190 is received in an annular groove 152 defined by the inside surface of axle tube 160 to handle outward axial thrust forces. A split 191 in snap ring 190 allows the ring to be compressed as it is slid inwardly into the bore of axle tube 160, expanding outwardly upon being seated in annular groove 168. An oil seal 196 is press-fit into axle tube 160 outboard of snap ring 190 to help maintain lubricating fluids therein.

[0025] Each needle roller 192 disposed in outer cup 182 includes a cylindrical rolling surface extending between a first end face 194 and a second end face 196 thereof. Each first and second end face 194 and 196 is transverse to a longitudinal center axis of the

corresponding needle roller 192. As such, when needle rollers 192 are disposed between the outer surface of axle shaft 150 and outer cup 182, first end faces 192 and second end faces 196 are parallel to first annular flange 186 and second annular flange 188, respectively, of outer cup 182.

[0026] As best seen in Figure 5, during vehicle operations, axial thrust forces on axle shaft 150 are transferred to annular housing 102 due to the position of C-rings 130 within annular groove 152 of axle shaft 150. When the axial thrust force is directed outwardly, the axial thrust force is transferred from C-rings 130 to the outboard annular sidewall 106 of annular housing 102, which is limitedly axially movable, until it abuts first end 172 of annular sleeve 170. Note, when the outward axial thrust force is low enough, the press-fit between annular sleeve 170 and axle tube 160 may be great enough to prevent outward motion of axle shaft 150. However, when the thrust force is great enough, annular sleeve 170 transfers the axial thrust force to outer cup 182 of radial bearing assembly 180, which in turn transfers the axial thrust force to snap ring 190, provided the axial thrust force is large enough. Snap ring 190 ultimately transfers the axial thrust force to axle tube 160. As previously noted, in alternate embodiments, snap ring 190 is not required where the press-fits between outer cup 182, annular sleeve 170 and axle tube 160 exceed maximum expected outward axial thrust forces on axle shaft 150. [0027] When axial thrust force caused by vehicle operations is directed inwardly, the axial thrust force transferred to annular housing 102 by C-rings 130 may, in turn, be transferred from annular housing 102 to axle tube 160 by way of its abutment with annular ledge 166. However, inward axial thrust forces acting on axle shaft 150 are preferably handled by abutment of the axle shaft's innermost end with a cross shaft 20 (Figures 3 and 4) of the axle's differential, in the manner previously discussed.

[0028] While one or more preferred embodiments of the invention are described above, it should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit thereof. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.

Claims

What is Claimed:

1. An axle assembly of a vehicle, comprising:

a differential assembly;

a first axle tube extending outwardly from a first side of the differential assembly, the first axle tube including a proximal end adjacent the differential assembly, an opposite distal end, and an axle bore extending therebetween;

a first axle shaft rotatably received in the first axle tube, the first axle shaft including a proximal end disposed in the differential assembly, an opposite distal end extending outwardly from the distal end of the first axle shaft, and an annular groove disposed in its outer surface; and

an annular housing that is disposed within the axle bore of the first axle tube and is non- rotatably fixed to the axle tube, the annular housing defining an annular groove in which at least one C-ring is retractably received,

wherein the at least one C-ring is selectively insertable into and out of the annular

groove of the axle shaft.

2. The axle assembly of claim 1 , further comprising a radial bearing assembly including an outer race and a plurality of roller elements rotatably received therein, the radial bearing assembly being disposed within the axle bore of the first axle tube axially outwardly of the annular sleeve.

3. The axle assembly of claim 2, wherein the outer race of the bearing assembly is axially fixed within the axle bore.

4. The axle assembly of claim 2, wherein the radial bearing assembly further comprises a first annular flange and a second annular flange depending radially inwardly from opposing ends of the outer race.

5. The axle assembly of claim 2, further comprising a snap ring that is axially fixed with respect to the first axle tube and is adjacent the outer race of the radial bearing assembly.

6. The axle assembly of claim 2, further comprising an annular sleeve disposed in the axle bore between the annular housing and the radial bearing assembly.

7. The axle assembly of claim 6, wherein the annular sleeve is received in the axle bore in a press-fit.

8. The axle assembly of claim 1 , wherein the at least one C-ring is biased radially inwardly into the annular groove of the axle shaft by a spring.

9. The axle assembly of claim 1 , further comprising:

a threaded fastener; and

a threaded bore defined in the at least one C-ring,

wherein the threaded fastener is rotatably received in the threaded bore such that the at least one C-ring moves radially outwardly with regard to the axle shaft and into the annular groove of the annular housing when the threaded fastener is rotated in a first direction, and the at least one C-ring moves radially inwardly with regard to the axle shaft when the threaded fastener is rotated in an opposite second direction.

10. An axle assembly of a vehicle, comprising:

a differential assembly;

an annular housing that is disposed within the axle bore of the first axle tube, the annular housing defining an annular groove in which at least one C-ring is retractably received,

wherein the at least one C-ring is selectively insertable into and out of the annular groove of the axle shaft.

11. The axle assembly of claim 10, wherein the annular housing is non-rotatably fixed to the axle tube.

12. The axle assembly of claim 10, further comprising a radial bearing assembly including an outer race and a plurality of roller elements rotatably received therein, the radial bearing assembly being disposed within the axle bore of the first axle tube axially outwardly of the annular sleeve.

13. The axle assembly of claim 12, wherein the outer race of the bearing assembly is axially fixed within the axle bore.

14. The axle assembly of claim 12, wherein the radial bearing assembly further comprises a first annular flange and a second annular flange depending radially inwardly from opposing ends of the outer race.

15. The axle assembly of claim 12, further comprising a snap ring that is axially fixed with respect to the first axle tube and is adjacent the outer race of the radial bearing assembly.

16. The axle assembly of claim 10, further comprising an annular sleeve disposed in the axle bore between the annular housing and the radial bearing assembly.

17. The axle assembly of claim 16, wherein the annular sleeve is received in the axle bore in a press-fit.

18. The axle assembly of claim 10, wherein the at least one C-ring is biased radially inwardly into the annular groove of the axle shaft by a spring.

19. The axle assembly of claim 10, further comprising:

a threaded fastener; and

a threaded bore defined in the at least one C-ring,