Multi-motor drive system for a work machine

• US 20060191168A1
• Filed: 02/28/2005
• Published: 08/31/2006
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Casey, Kent A., Moring, Rodger L.
• Granted Patent: US 7,441,623 B2
• Time in Patent Office: Days
• US Class Current: 37/348
• CPC Class Codes: B60K 17/046 with planetary gearing having orbital motion
• CPC Class Codes: B60K 17/34 for driving both front and rear wheels, e.g. four wheel drive vehicles arrangement or mounting of control devices for changing number of driven wheels B60K23/08
• CPC Class Codes: B60K 2007/0038 the motor moving together with the wheel axle
• CPC Class Codes: B60K 2007/0092 the motor axle being coaxial to the wheel axle
• CPC Class Codes: B60K 5/00 Arrangement or mounting of internal-combustion or jet-propulsion units B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60K 7/0015 the motor being hydraulic

Abstract

A multi-motor drive system for a work machine has a first traction device and a second traction device substantially aligned transversely of a primary travel-direction of the work machine. The drive system also has a first drive-group power-transfer system that connects the first traction device and the second traction device. The drive system may also include a third traction device and a fourth traction device substantially aligned transversely of the primary travel-direction of the work machine. Further, the drive system also includes a second drive-group power-transfer system that connects the third traction device and the fourth traction device. Additionally, the drive system has an inter-group power-transfer system that connects the first drive-group power-transfer system to the second drive-group power-transfer system. A first drive motor may operatively connect to the first drive-group power-transfer system separate of the inter-group power-transfer system. Moreover, the drive system may include a second drive motor operatively connected to the second drive-group power-transfer system separate of the inter-group power-transfer system.

Claims

1. A multi-motor drive system for a work machine, comprising:

a first traction device and a second traction device substantially aligned transversely of a primary travel-direction of the work machine;

a first drive-group power-transfer system that connects the first traction device and the second traction device;

a third traction device and a fourth traction device substantially aligned transversely of the primary travel-direction of the work machine;

a second drive-group power-transfer system that connects the third traction device and the fourth traction device;

an inter-group power-transfer system that connects the first drive-group power-transfer system to the second drive-group power-transfer system;

a first drive motor operatively connected to the first drive-group power-transfer system separate from the inter-group power-transfer system; and

a second drive motor operatively connected to the second drive-group power-transfer system separate from the inter-group power-transfer system.

2. The multi-motor drive system of claim 1, wherein the first drive-group power-transfer system includes a first differential unit and the second drive-group power-transfer system includes a second differential unit.

3. The multi-motor drive system of claim 2, wherein the inter-group power-transfer system connects to the first drive-group power-transfer system through the first differential unit and the inter-group power-transfer system connects to the second drive-group power-transfer system through the second differential unit.

4. The multi-motor drive system of claim 3, wherein the first traction device and the second traction device are pivotally steerable relative to the third traction device and the fourth traction device.

5. The multi-motor drive system of claim 2, further including:

a third drive motor operatively connected to the first drive-group power-transfer system separate from the inter-group power-transfer system and at a point such that the first differential unit is connected between the first drive motor and the third drive motor; and

a fourth drive motor operatively connected to the second drive-group power-transfer system separate from the inter-group power-transfer system and at a point such that the second differential unit is connected between the second drive motor and the fourth drive motor.

6. The multi-motor drive system of claim 1, wherein the first traction device and the second traction device are pivotally steerable relative to the third traction device and the fourth traction device.

7. The multi-motor drive system of claim 1, wherein the first drive-group power-transfer system includes a motion-conversion unit and a drive shaft, and an output shaft of the first drive motor connects to the drive shaft through components of the motion-conversion unit.

8. The multi-motor drive system of claim 1, further including:

an inter-group drive motor operatively connected to the inter-group power-transfer system.

9. A method of operating a drive system for a work machine, the drive system having a first drive-group with two traction devices substantially aligned transversely of a primary travel-direction of the work machine, a first drive-group power-transfer system that connects the two traction devices of the first drive-group, and a first drive motor operatively connected to the first drive-group power-transfer system, the drive system having a second drive-group spaced from the first drive-group in the primary travel-direction and including two traction devices substantially aligned transversely of the primary travel-direction and a second drive-group power-transfer system that connects the two traction devices of the second drive-group, and the drive system having an inter-group power-transfer system that connects the first drive-group power-transfer system to the second drive-group power-transfer system, the method including:

transferring power from the first drive motor, through at least part of the first drive-group power-transfer system, the inter-group power-transfer system, and at least part of the second drive-group power-transfer system, to at least one of the traction devices of the second drive-group.

10. The method of claim 9, further including:

accommodating a first speed differential between the traction devices of the first drive-group; and

accommodating a second speed differential between the traction devices of the second drive-group, wherein the second speed differential has a different magnitude than the first speed differential.

11. The method of claim 10, further including:

pivoting the traction devices of at least one of the first drive-group and the second drive-group to induce turning of the work machine relative to the primary-travel direction.

12. The method of claim 11, further including:

transferring power from a second drive motor to the second drive-group power-transfer system separately from the inter-group power-transfer system.

13. The method of claim 10, wherein the first drive-group power-transfer system includes a first differential unit that accommodates the first speed differential and the second drive-group power-transfer system includes a second differential unit that accommodates the second speed differential.

14. The method of claim 10, further including:

transferring power from a second drive motor to the second drive-group power-transfer system separately from the inter-group power-transfer system.

15. The method of claim 9, further including:

transferring power from a second drive motor to the second drive-group power-transfer system separately from the inter-group power-transfer system.

16. The method of claim 15, further including:

transferring power from a third drive motor, through at least part of the first drive-group power-transfer system, the inter-group power-transfer system, and at least part of the second drive-group power-transfer system, to at least one of the traction devices of the second drive-group; and

transferring power from a fourth drive motor to the second drive-group power-transfer system separately from the inter-group power-transfer system.

17. The method of claim 9, further including:

transferring power from an inter-group drive motor, through at least part of the inter-group power-transfer system and at least part of the second drive-group power-transfer system, to at least one of the traction devices of the second drive-group.

18. The method of claim 9, further including:

pivoting the traction devices of at least one of the first drive-group and the second drive-group to induce turning of the work machine relative to the primary travel-direction.

19. A work machine, comprising:

a power source;

a power-conversion unit operatively coupled to the power source;

a first traction device and a second traction device substantially aligned transversely of a primary travel-direction of the work machine;

a first drive-group power-transfer system, including a first differential unit, that connects the first traction device and the second traction device;

a third traction device and a fourth traction device substantially aligned transversely of the primary travel-direction of the work machine;

a second drive-group power-transfer system, including a second differential unit, that connects the third traction device and the fourth traction device;

an inter-group power-transfer system that connects the first drive-group power-transfer system to the second drive-group power-transfer system;

a first drive motor operatively connected to the first drive-group power-transfer system separate from the inter-group power-transfer system;

a second drive motor operatively connected to the first drive-group power-transfer system separate from the inter-group power-transfer system and at a point such that the first differential unit is connected between the first drive motor and the second drive motor;

a third drive motor operatively connected to the second drive-group power-transfer system separate from the inter-group power-transfer system; and

a fourth drive motor operatively connected to the second drive-group power-transfer system separate from the inter-group power-transfer system and at a point such that the second differential unit is connected between the third drive motor and the fourth drive motor.

20. The work machine of claim 19, wherein the inter-group power-transfer system connects to the first drive-group power-transfer system through the first differential unit and the inter-group power-transfer system connects to the second drive-group power-transfer system through the second differential unit.

21. The work machine of claim 20, wherein the first traction device and the second traction device are pivotally steerable relative to the third traction device and the fourth traction device.

22. The work machine of claim 19, wherein the first traction device and the second traction device are pivotally steerable relative to the third traction device and the fourth traction device.

23. The work machine of claim 19, further including:

an inter-group drive motor operatively connected to the inter-group power-transfer system.