Wheel end tire air pump

• US 20040216827A1
• Filed: 05/02/2003
• Published: 11/04/2004
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: ArvinMeritor Technology LLC (Meritor, Inc. (Nevada))
• Original Assignee: ArvinMeritor Technology LLC (Meritor, Inc. (Nevada))
• Inventors: Stanczak, Edmund A.
• Granted Patent: US 6,994,136 B2
• Time in Patent Office: Days
• US Class Current: 152/419
• CPC Class Codes: B60C 23/004 the control being done on the wheel, e.g. using a wheel-mounted reservoir
• CPC Class Codes: B60C 23/127 the pumps being mounted on the hubs

Abstract

A wheel end assembly includes a self-contained air pump mechanism that maintains tire pressure at a desired level. The pump mechanism includes a piston and cylinder assembly that rotate with the tire. A linkage assembly drives the piston within the cylinder as the wheel end assembly rotates to pump air into the tire via a valve. The linkage assembly includes a first link fixed to a non-rotating wheel end component and a second link that rotates relative to the first link and which is coupled to drive the piston within the cylinder. The tire valve is in fluid communication with the cylinder and automatically opens when air pressure in the tire falls below a predetermined level and automatically closes when the air pressure achieves the predetermined level. An atmospheric valve is in fluid communication with the cylinder, and automatically opens to recharge the cylinder once the initial pressure charge has been delivered to the tire.

Claims

1. A vehicle wheel end assembly comprising:

a non-rotating axle component defining a lateral axis;

a rotating axle component supported by at least one bearing for rotation relative to said non-rotating axle component about said lateral axis;

a pump mechanism including a first pump member fixed to said non-rotating axle component and a second pump member mounted for rotation with said rotating axle component; and

at least one valve adapted to be in fluid communication with a tire wherein said first pump member drives said second pump member to inflate the tire via said valve when pressure within the tire falls below a predetermined level.

2. The vehicle wheel end assembly as set forth in claim 1 wherein said pump mechanism is self-contained within said rotating and non-rotating axle components to operate solely at the tire.

3. The vehicle wheel end assembly as set forth in claim 1 wherein said non-rotating axle component comprises a trailer axle with a spindle and said rotating axle component comprises a wheel hub supported by said bearing on said spindle.

4. The vehicle wheel end assembly as set forth in claim 1 wherein said first pump member includes a pump drive shaft keyed to said non-rotating axle component and said second pump member includes a piston and a cylinder.

5. The vehicle wheel end assembly as set forth in claim 4 including a rotating shaft coupled at one end to said pump drive shaft and coupled at an opposite end to drive said piston.

6. The vehicle wheel end assembly as set forth in claim 5 wherein said pump mechanism defines a central pump axis that is spaced apart from and parallel to said lateral axis.

7. The vehicle wheel end assembly as set forth in claim 6 wherein said central pump axis is defined at a connection between said pump drive shaft and said rotating shaft.

8. The vehicle wheel end assembly as set forth in claim 6 wherein said piston remains at a constant predetermined distance from said central pump axis as said rotating axle component rotates.

9. The vehicle wheel end assembly as set forth in claim 1 wherein said pump mechanism rotates about an axis that is non-concentric with said lateral axis.

10. The vehicle wheel end assembly as set forth in claim 1 wherein said at least one valve comprises a first one-way check valve in fluid communication with the tire and a second one-way check valve in fluid communication with atmosphere.

11. The vehicle wheel end assembly as set forth in claim 10 wherein said pump mechanism automatically opens said first one-way check valve when the pressure within the tire falls below said predetermined level and said first one-way check valve automatically closes when the pressure within the tire achieves said predetermined level.

13. The vehicle wheel end assembly as set forth in claim 10 wherein said pump mechanism freewheels when tire pressure is greater than or equal to said predetermined level with said first and second one-way check valves held closed.

14. The vehicle wheel end assembly as set forth in claim 1 including at least one sensor for monitoring a vehicle characteristic wherein rotation of said rotating axle component relative to said first pump member generates a voltage to power said at least one sensor.

15. The vehicle wheel end assembly as set forth in claim 14 wherein said vehicle characteristic is tire pressure.

16. The vehicle wheel end assembly as set forth in claim 1 wherein said first pump member includes a pump drive shaft fixed to said non-rotating axle component and said second pump member comprises a rotary compressor pump.

17. The vehicle end assembly as set forth in claim 1 wherein said first pump member includes a pump drive shaft keyed to said non-rotating axle component and said second pump member includes a rotating casing operably coupled to a plurality of movable plates spaced apart from one another to define a plurality of compartments.

18. The vehicle wheel end assembly as set forth in claim 17 wherein each of said plurality of movable plates moves in a generally linear path and in a radial direction relative to said pump drive shaft to progressively increase compartment size during a first portion of one revolution of said rotating casing to draw in air at atmospheric pressure and to progressively decrease compartment size during a second portion of one revolution of said rotating casing to compress the air for delivery to the tire.

12. The vehicle wheel end assembly as set forth in 10 wherein said second pump member includes a pressure charge held within a chamber, said pressure charge being automatically delivered to the tire via said first one-way check valve when the pressure within the tire falls below said predetermined level and wherein said second one-way check valve automatically draws air into said chamber from the atmosphere once said chamber has been discharged into the tire.

19. An axle assembly with a pair of wheel ends comprising:

a beam defining a central axis;

a first wheel end including a first non-rotating spindle mounted to one end of said beam and a first wheel hub rotatably supported on said first non-rotating spindle;

a second wheel end including a second non-rotating spindle mounted to an opposite end of said beam; and

a second wheel hub rotatably supported on said second non-rotating spindle;

a first air pump mechanism including a first pump member fixed to said first non-rotating spindle, a second pump member, and at least one first valve in fluid communication with a first tire wherein said first pump member drives said second pump member as said first wheel hub rotates to inflate the first tire via said first valve when air pressure in the first tire falls below a first predetermined level; and

a second air pump mechanism including a third pump member fixed to said second non-rotating spindle, a fourth pump member, and at least one second valve in fluid communication with the second tire wherein said third pump member drives said fourth pump member as said second wheel hub rotates to inflate the second tire via said second valve when air pressure in the second tire falls below a second predetermined level.

20. The axle assembly as set forth in claim 19 wherein said first and second air pump mechanisms define first and second pump axes that are non-concentric with said central axis.

21. The assembly as set forth in claim 19 wherein said first and second air pump mechanisms operate automatically and independently frown each other.

22. The assembly as set forth in claim 21 wherein said beam comprises a non-drive trailer axle.

23. The axle assembly as set forth in claim 21 wherein said beam comprises an axle housing for a drive axle.

24. A trailer axle wheel end assembly comprising:

a spindle mounted to an axle beam defining a central axis;

a wheel hub rotatably supported on said spindle for rotation about said central axis; and

an air pump including a first link fixed to said spindle, a piston and cylinder assembly mounted for rotation with said wheel hub, and a second link interconnecting said first link to said piston and cylinder assembly such that as said wheel hub rotates said first link drives said second link which drives said piston and cylinder assembly to automatically pump air into a tire when air pressure within the tire falls below a predetermined level.

25. The trailer axle wheel assembly as set forth in claim 24 including at least one valve in fluid communication with the tire and wherein said piston and cylinder assembly includes a pressure chamber in fluid communication with said valve, said pressure chamber for holding a pressure charge.

26. The trailer axle wheel end assembly as set forth in claim 25 wherein said at least one valve includes a first one-way check valve that automatically opens when air pressure in the tire falls below said predetermined level to allow said pressure charge to be transferred into the tire.

27. The trailer axle wheel end assembly as set forth in claim 26 wherein said at least one valve includes a second one-way check valve in fluid communication with said pressure chamber and atmosphere, said second one-way check valve automatically opening to draw air into said pressure chamber from the atmosphere when said pressure charge is delivered to the tire via said first one-way check valve.

28. The trailer axle wheel end assembly as set forth in claim 27 wherein said first link is directly attached to said spindle.

29. The trailer axle wheel end assembly as set forth in claim 28 wherein said second link rotates relative to said first link with a connection between said first and second links defining a pump centerline that is non-concentric with said central axis.

30. The trailer axle wheel end assembly as set forth in claim 29 wherein said second link drives said piston and cylinder assembly in a direction transverse to said central axis.

31. The trailer axle wheel end assembly as set forth in claim 30 wherein said piston and cylinder assembly includes a cylinder that forms said pressure chamber and a piston with said cylinder moving relative to said pump centerline and said piston remaining at an approximately equal radial distance from said pump centerline as said wheel hub rotates.