Axle Assembly

• US 20150167813A1
• Filed: 02/24/2015
• Published: 06/18/2015
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: American AXLE & Manufacturing Incorporated (American AXLE & Manufacturing Holdings Incorporated)
• Original Assignee: American AXLE & Manufacturing Incorporated (American AXLE & Manufacturing Holdings Incorporated)
• Inventors: Downs, James P., Valente, Paul J.
• Granted Patent: US 9,677,656 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60B 35/16 Axle housings
• CPC Class Codes: B60K 17/165 provided between independent half axles B60K17/18, B60K17/20 take precedence
• CPC Class Codes: F16C 19/546 Systems with spaced apart rolling bearings including at least one angular contact bearing
• CPC Class Codes: F16C 2361/31 Axle
• CPC Class Codes: F16C 2361/61 Toothed gear systems, e.g. support of pinion shafts in general F16H57/02
• CPC Class Codes: F16C 33/581 integral with other parts, e.g. with housings or machine elements such as shafts or gear wheels
• CPC Class Codes: F16H 2048/385 of the ring or crown gear
• CPC Class Codes: F16H 2048/405 characterised by features of the bearing of the rotating case
• CPC Class Codes: F16H 2048/423 characterised by bearing arrangement
• CPC Class Codes: F16H 2048/426 characterised by spigot bearing arrangement, e.g. bearing for supporting the free end of the drive shaft pinion
• CPC Class Codes: F16H 48/08 comprising bevel gears
• CPC Class Codes: F16H 48/22 using friction clutches or brakes
• CPC Class Codes: F16H 48/38 Constructional details the outer casing comprising the differential and supporting input and output shafts F16H57/037
• CPC Class Codes: F16H 48/40 characterised by features of the rotating cases
• CPC Class Codes: F16H 48/42 characterised by features of the input shafts, e.g. mounting of drive gears thereon
• CPC Class Codes: F16H 57/021 Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings
• CPC Class Codes: F16H 57/031 characterised by covers or lids for gearboxes
• CPC Class Codes: F16H 57/037 Gearboxes for accommodating differential gearings rotating cases for differential gearings F16H48/40

Abstract

An axle assembly having an input pinion with a pinion gear, which is received in an axle housing and rotatable about a first axis, and a pinion shaft. The pinion gear is meshed with a ring gear that is coupled to a differential assembly. A head bearing, which is disposed on a first axial end of the input pinion, supports the input pinion for rotation relative to the housing about the first axis. A tail bearing supports the input pinion for rotation relative to the housing about the first axis. The pinion gear is disposed axially between the tail bearing and the head bearing. A bearing groove is formed into the pinion shaft and the bearing elements are received into the bearing groove such that an inner bearing race of the tail bearing is unitarily and integrally formed with the pinion shaft.

Claims

1. An axle assembly comprising:

a housing;

an input pinion having a pinion gear and a pinion shaft, the input pinion being received in the housing and being rotatable about a first axis;

a ring gear meshed with the pinion gear and rotatable about a second axis that is transverse to the first axis;

a differential assembly having a differential case and a pair of output members, the differential case being driven by the ring gear; and

a head bearing and a tail bearing for supporting the input pinion for rotation relative to the housing about the first axis, the head bearing being disposed on a first axial end of the input pinion, the tail bearing being a four-point contact ball bearing having a plurality of bearing elements, an inner race and an outer race, the pinion gear being disposed axially between the tail bearing and the head bearing;

wherein a bearing groove is formed into the pinion shaft and wherein the bearing elements are received into the bearing groove such that the inner bearing race is unitarily and integrally formed with the pinion shaft.

2. The axle assembly of claim 1, wherein the outer race comprises a first outer race member and a second outer race member that are axially separated from one another.

3. The axle assembly of claim 2, further comprising a bearing adjuster that is threadably coupled to the housing, the bearing adjuster being configured to move the first outer bearing race member axially toward the second outer bearing race member to pre-load the tail bearing.

4. The axle assembly of claim 3, further comprising a pinion shaft seal that is mounted to the housing, the pinion shaft seal having at least one lip seal that is sealingly engaged to the pinion shaft.

5. The axle assembly of claim 4, wherein the at least one lip seal is received axially through the bearing adjuster.

6. The axle assembly of claim 1, further comprising a yoke flange non-rotatably coupled to the input pinion.

7. The axle assembly of claim 6, wherein the input pinion defines an internal cavity that is formed through a second, opposite axial end, wherein the input pinion has a first coupling portion having a plurality of internal spline teeth, that border the internal cavity, and wherein the yoke flange includes a second coupling portion that is received into the internal cavity, the second coupling portion having a plurality of external spline teeth that matingly engage the internal spline teeth.

8. The axle assembly of claim 7, further comprising a pinion shaft seal that is mounted to the housing, the pinion shaft seal having at least one lip seal that is sealingly engaged to the pinion shaft.

9. The axle assembly of claim 8, wherein the yoke flange comprises a bearing shield that extends radially outwardly from the second coupling portion to cover an axial end of the pinion shaft seal.

10. The axle assembly of claim 6, wherein the yoke flange is unitarily and integrally formed with the input pinion.

11. The axle assembly of claim 6, wherein the yoke flange is formed of aluminum.

12. The axle assembly of claim 1, wherein the head bearing comprises a plurality of bearing elements, wherein the pinion gear comprises a cylindrical extension, and wherein the bearing elements of the head bearing are in direct contact with a surface of the cylindrical extension.

13. The axle assembly of claim 1, wherein the head bearing comprises a plurality of roller elements.

14. An axle assembly comprising:

a housing;

an input pinion having a pinion gear and a pinion shaft, the input pinion being received in the housing and being rotatable about a first axis;

a ring gear meshed with the pinion gear and rotatable about a second axis that is transverse to the first axis;

a differential assembly having a differential case and a pair of output members, the differential case being driven by the ring gear; and

a head bearing and a tail bearing for supporting the input pinion for rotation relative to the housing about the first axis, the head bearing and the tail bearing being disposed along the first axis on opposite sides of the pinion gear, wherein the tail bearing is configured to handle loads directed along the first axis from the input pinion to the housing in a direction from the head bearing to the tail bearing and wherein the tail bearing comprises an inner bearing race, which is defined by a bearing groove that is formed into the pinion shaft, and a plurality of bearing elements that are received into the bearing groove such that an inner bearing race of the tail bearing is unitarily and integrally formed with the pinion shaft.

15. The axle assembly of claim 14, wherein the tail bearing is a four-point contact ball bearing.

16. The axle assembly of claim 14, wherein the head bearing comprises a plurality of rollers.

17. The axle assembly of claim 14, wherein an outer race of the tail bearing comprises a first outer race member and a second outer race member that are axially separated from one another.

18. The axle assembly of claim 17, further comprising a bearing adjuster that is threadably coupled to the housing, the bearing adjuster being configured to move the first outer bearing race member axially toward the second outer bearing race member to pre-load the tail bearing.

19. The axle assembly of claim 18, further comprising a pinion shaft seal that is mounted to the housing, the pinion shaft seal having at least one lip seal that is sealingly engaged to the pinion shaft.

20. The axle assembly of claim 19, wherein the at least one lip seal is received axially through the bearing adjuster.

21. The axle assembly of claim 14, further comprising a yoke flange non-rotatably coupled to the input pinion.

22. The axle assembly of claim 21, wherein the input pinion defines an internal cavity that is formed through a second, opposite axial end, wherein the input pinion has a first coupling portion having a plurality of internal spline teeth, that border the internal cavity, and wherein the yoke flange includes a second coupling portion that is received into the internal cavity, the second coupling portion having a plurality of external spline teeth that matingly engage the internal spline teeth.

23. The axle assembly of claim 22, further comprising a pinion shaft seal that is mounted to the housing, the pinion shaft seal having at least one lip seal that is sealingly engaged to the pinion shaft.

24. The axle assembly of claim 23, wherein the yoke flange comprises a bearing shield that extends radially outwardly from the second coupling portion to cover an axial end of the pinion shaft seal.

25. The axle assembly of claim 21, wherein the yoke flange is unitarily and integrally formed with the input pinion.

26. The axle assembly of claim 21, wherein the yoke flange is formed of aluminum.