Axle assembly having mechanism for circulating lubricating fluid to wheel ends

1. An axle assembly comprising:

an axle housing having a carrier housing portion and an axle shaft housing portion, the axle shaft housing portion including a shaft passage that is arranged about a longitudinal passage axis;

a differential assembly supported in the carrier housing for rotation about a rotational axis that is coincident with the longitudinal passage axis;

an axle shaft received in the axle shaft housing portion and coupled to the differential assembly, the axle shaft including a cylindrical body portion having a first diameter;

an annular disc mounted on the axle shaft and having a central aperture through which the cylindrical body portion is received, the central aperture having a second diameter that is larger than the first diameter; and

a pair of change members in the shaft passage, the change members being axially spaced-apart along the longitudinal passage axis;

wherein the annular disc is pivotable on the body portion between a first position, in which the annular disc is disposed at a first angle relative to a plane that extends perpendicular to the longitudinal passage axis, and a second position, in which the annular disc is disposed at a second angle relative to the plane that extends perpendicular to the longitudinal passage axis, the first and second angles extending from opposite sides of the plane; and

wherein contact between the change members and the annular disc while the axle shaft rotates causes the annular disc to move between the first and second positions.

2. The axle assembly of claim 1 , wherein the first and second angles are equal in magnitude.

3. The axle assembly of claim 1 , wherein the axle shaft housing portion includes an axle tube and wherein the change members are discrete structures that are coupled to the axle tube.

4. The axle assembly of claim 1 , wherein the carrier housing portion includes a carrier housing and a pair of bearing caps, wherein the carrier housing defines a differential cavity, and wherein the differential assembly includes a differential case and a pair of bearings, the bearings being received between the carrier housing and the bearing caps and supporting the differential case for rotation in the carrier housing.

5. The axle assembly of claim 4 , wherein the differential cavity extends between one of the bearing caps and the axle shaft housing portion.

6. The axle assembly of claim 4 , wherein the change members are located outboard of the bearings.

7. The axle assembly of claim 1 , wherein the central aperture is a cylindrical hole.

8. The axle assembly of claim 1 , wherein the central aperture is defined by a contoured surface.

9. The axle assembly of claim 8 , wherein at least a portion of the contoured surface is defined by a radius.

10. The axle assembly of claim 8 , wherein at least a portion of the contoured surface is defined by a chamfer.

11. The axle assembly of claim 1 , wherein the change members are coupled to the axle shaft for rotation therewith.

12. An axle assembly comprising:

an axle housing having a carrier housing portion and an axle shaft housing portion, the axle shaft housing portion including a shaft passage that is arranged about a longitudinal passage axis;

a differential assembly supported in the carrier housing for rotation about a rotational axis that is coincident with the longitudinal passage axis;

an axle shaft received in the axle shaft housing portion and coupled to the differential assembly, the axle shaft including an unthreaded body portion having a first diameter;

an annular disc mounted on the axle shaft and having a central aperture through which the unthreaded body portion is received, the central aperture having a second diameter that is larger than the first diameter; and

a pair of change members in the shaft passage, the change members being axially spaced-apart along the longitudinal passage axis;

wherein rotation of the axle shaft causes the annular disc to translate on the unthreaded body portion between the change members and wherein a direction in which the annular disc translates is changed through contact between the annular disc and the change members.

13. The axle assembly of claim 12 , wherein the axle shaft housing portion includes an axle tube and wherein the change members are discrete structures that are coupled to the axle tube.

14. The axle assembly of claim 12 , wherein the carrier housing portion includes a carrier housing and a pair of bearing caps, wherein the carrier housing defines a differential cavity, and wherein the differential assembly includes a differential case and a pair of bearings, the bearings being received between the carrier housing and the bearing caps and supporting the differential case for rotation in the carrier housing.

15. The axle assembly of claim 14 , wherein the differential cavity extends between one of the bearing caps and the axle shaft housing portion.

16. The axle assembly of claim 14 , wherein the change members are located outboard of the bearings.

17. The axle assembly of claim 12 , wherein the central aperture is a cylindrical hole.

18. The axle assembly of claim 12 , wherein the central aperture is defined by a contoured surface.

19. The axle assembly of claim 18 , wherein at least a portion of the contoured surface is defined by a radius.

20. The axle assembly of claim 18 , wherein at least a portion of the contoured surface is defined by a chamfer.

21. The axle assembly of claim 12 , wherein the change members are coupled to the axle shaft for rotation therewith.