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Independently rotating wheels with planetary drive

Imported: 24 Feb '17 | Published: 06 Jan '04

I-Chao Chung, Leonard R. Elliott, Michael E. Johnson

USPTO - Utility Patents

Abstract

A wheel end assembly having a dual wheel configuration includes independently rotating wheel hubs to reduce tire wear. The wheel end includes a first planetary gear assembly with a sun gear driven by a differential side gear and a ring gear for driving one wheel hub. A second planetary gear assembly with a sun gear driven by a differential side gear and a ring gear drives another wheel hub. A differential assembly is coupled to the first and second sun gears to allow the first and second wheel hubs to rotate relative to one another as the vehicle executes turning maneuvers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic view of a typical off-highway vehicle powertrain.

FIG. 1B is a schematic view of a typical on-highway vehicle powertrain.

FIG. 2 is a cross-sectional view of a top half of one embodiment of a wheel end assembly incorporating the subject invention.

FIG. 3 is a cross-sectional view taken along lines

3

3 of FIG.

2.

FIG. 4 is a cross-sectional view of a top half of an alternate embodiment of a planetary drive assembly incorporating the subject invention.

Claims

1. A wheel end apparatus comprising:

2. An apparatus as set forth in claim 1 including an axle housing joined to said spindle.

3. An apparatus as set forth in claim 1 wherein said input member is in direct driving engagement with said axle shaft.

4. An apparatus as set forth in claim 1 wherein said first output is independent from said second output.

5. An apparatus as set forth in claim 1 wherein said input member includes first and second sun gears driven by a differential assembly and said first output includes a first ring gear coupled to said first wheel hub and said second output includes a second ring gear coupled to said second wheel hub.

6. An apparatus as set forth in claim 5 wherein said first ring gear and said first wheel hub are integrally formed as one piece and said second ring gear and said second wheel hub are integrally formed as one piece.

7. An apparatus as set forth in claim 5 including a first planetary gear set in meshing engagement with said first sun gear and said first ring gear and a second planetary gear set in meshing engagement with said second sun gear and said second ling gear wherein said first and second planetary gear sets include a plurality of planet gears supported on planet shafts.

8. An apparatus as set forth in claim 7 wherein said planet shafts are fixed to said spindle.

9. An apparatus as set forth in

7 wherein said spindle includes a first set of slots through which said first planetary gear set extends and a second set of slots through which said second planetary gear set extends wherein said first and second sets of slots are wider than said first and second planetary gear sets to permit said planet gears to rotate freely relative to said spindle.

10. An apparatus as set forth in claim 7 wherein said differential assembly is driven by said axle shaft to drive first and second sun gears.

11. An apparatus as set forth in claim 10 wherein said differential assembly is positioned between said first and second sun gears.

12. An apparatus as set forth in claim 10 wherein said differential assembly includes a first differential side gear mounted for rotation with said first sun gear, a second differential side gear mounted for rotation with said second sun gear, and differential pinions in meshing engagement with said first and second differential side gears to allow rotational speed differential between said first and second wheel hubs.

13. An apparatus as set forth in claim 12 wherein said first sun gear and said first differential side gear are integrally formed as one piece and said second sun gear and said second differential side gear are integrally formed as one piece.

14. A wheel end apparatus comprising:

15. An apparatus as set forth in claim 14 including a first planetary gear set having a first plurality of planet gears in meshing engagement with said first sun gear and said first ring gear and a second planetary gear set having a second plurality of planet gears in meshing engagement with said second sun gear and said second ring gear.

16. An apparatus as set forth in claim 14 including a first planetary gear set having a first plurality of planet gears in meshing engagement with said first sun gear, a second planetary gear set having a second plurality of planet gears in meshing engagement with said first ring gear and coupled to said first plurality of planet gears, a third planetary gear set having a third plurality of planet gears in meshing engagement with said second sun gear, and a fourth planetary gear set having a fourth plurality of planet gears in meshing engagement with said second ring gear and coupled to said third plurality of planet gears.

17. An apparatus as set forth in claim 14 wherein said differential assembly includes a first differential side gear mounted for rotation with said first sun gear, a second differential side gear mounted for rotation with said second sun gear, and differential pinions in meshing engagement with said first and second differential side gears to allow rotational speed differential between said first and second wheel hubs.

18. An apparatus as set forth in claim 17 including a differential spider driven by said axle shaft and supports said differential pinions for rotation.

19. An apparatus as set forth in claim 5 wherein each of said planet gears is mounted on a planet shaft fixed to said spindle.

20. An apparatus as set forth in claim 19 wherein each of said planet shaft supports one of said planet gears from said first planetary gear set and one of said planet gears from said second planetary gear set.

21. An apparatus as set forth in claim 19 wherein said planet gears do not rotate about said axis.