Claims
- 1. A power machine, comprising
- a base;
- a boom coupled to the base;
- a hydraulic boom actuator coupled to the boom to move the boom relative to the base;
- an arm coupled to the boom;
- a hydraulic arm actuator coupled to the boom and the arm to move the arm relative to the boom;
- a tool coupled to the arm;
- a tool actuator coupled to the tool to move the tool relative to the arm;
- a traction actuator coupled to the base to drive the power machine;
- a hydraulic power circuit including a first pump providing hydraulic fluid under pressure and a second pump providing hydraulic fluid under pressure;
- a traction valve mechanism coupled to the traction actuator to receive hydraulic fluid under pressure from one of the first and second pumps and selectively provide the hydraulic fluid to the traction actuator;
- a boom valve coupled to the first pump and to the boom actuator to receive hydraulic fluid under pressure from the first pump and selectively provide the hydraulic fluid to the boom actuator;
- an arm valve coupled to the second pump and the arm actuator to receive hydraulic fluid under pressure from the second pump and selectively provide the hydraulic fluid to the arm actuator; and
- a tool valve coupled in parallel with the arm valve and to the tool actuator to receive hydraulic fluid under pressure from the second pump and selectively provide the hydraulic fluid to the tool actuator;
- wherein at least one of the boom valve and the parallel connected arm valve and tool valve are coupled down stream of, and in series with, the traction valve mechanism.
- 2. The power machine of claim 1 wherein the traction actuator comprises:
- a first traction motor; and wherein the traction valve mechanism comprises:
- a first traction valve coupled to the first traction motor and coupled between the boom valve and the first pump, the first traction valve selectively providing hydraulic fluid from the first pump to the first traction motor.
- 3. The power machine of claim 2 wherein the traction actuator further comprises: a second traction motor; and wherein the traction valve mechanism comprises:
- a second traction valve coupled to the second traction motor and coupled between the second pump and the parallel connected arm valve and tool valve, and the second traction valve selectively providing hydraulic fluid from the second pump to the second traction motor.
- 4. The power machine of claim 3 wherein the hydraulic power circuit includes a third pump providing hydraulic fluid under pressure, and further comprising:
- a boost valve coupled to receive hydraulic fluid from the third pump and coupled to the first and second traction valves to selectively provide hydraulic fluid from the third pump to the first and second traction valves such that the first traction valve receives hydraulic fluid from the first and third pumps and the second traction valve receives hydraulic fluid from the second and third pumps.
- 5. The power machine of claim 4 wherein the third pump has a larger capacity than the first and wherein the third pump has a larger capacity than the second pump.
- 6. The power machine of claim 5 and further comprising:
- an operator support portion coupled to the base;
- a hydraulic slew motor coupled to move the operator support portion relative to the base; and
- a slew valve coupled to the third pump and coupled in series with at least one additional power actuator valve to receive the hydraulic fluid under pressure from the third pump and coupled to the slew motor to selectively provide hydraulic fluid to the slew motor.
- 7. The power machine of claim 6 and further comprising a boom offset cylinder coupled to the boom to pivot the boom relative to the base portion and wherein the at least one additional power actuator valve comprises a boom offset valve coupled to the boom offset cylinder to selectively provide hydraulic fluid to the boom offset cylinder, the boom offset valve being coupled down stream of the slew valve.
- 8. The power machine of claim 1 wherein the parallel-connected tool valve and arm valve are coupled down stream of the boom valve to receive hydraulic fluid from the first pump which is not diverted to the boom actuator by the boom valve, and further comprising:
- a pressure build-up valve coupled down stream of the parallel-connected tool valve and arm valve, the pressure build-up valve impeding hydraulic fluid flow from the first and second pumps to tank until a fluid pressure threshold is reached.
- 9. An excavator, comprising:
- a base;
- a first drive mechanism coupled to the base;
- a first traction motor coupled to drive the first drive mechanism;
- a second drive mechanism coupled to the base;
- a second drive motor coupled to drive the second drive mechanism;
- a hydraulic power circuit including a first pump providing hydraulic fluid under pressure, a second pump providing hydraulic fluid under pressure, and a third pump providing hydraulic fluid under pressure, and further comprising:
- a first traction valve coupled to the first pump and the first drive motor to selectively provide the hydraulic fluid from the first pump to the first drive motor;
- a second traction valve coupled to the second pump and the second drive motor to selectively provide the hydraulic fluid from the second pump to the second drive motor; and
- a boost valve coupled to the third pump and to the first and second drive motors to selectively provide the hydraulic fluid from the third pump to the first and second drive motors.
- 10. The excavator of claim 9 and further comprising:
- a first check valve coupled between the boost valve and the first drive motor; and
- a second check valve coupled between the boost valve and the second drive motor.
- 11. The excavator of claim 9 wherein the third pump has a larger capacity than the first and second pumps.
- 12. The excavator of claim 9 and further comprising:
- a boom coupled to the base;
- a hydraulic boom actuator coupled to the boom to move the boom relative to the base; and
- a boom valve coupled to the first traction valve and coupled to the boom actuator to receive hydraulic fluid under pressure from the first pump through the first traction valve and selectively provide the hydraulic fluid to the boom actuator.
- 13. The excavator of claim 12 and further comprising:
- an arm coupled to the boom;
- a hydraulic arm actuator coupled to the boom and the arm to move the arm relative to the boom;
- a tool coupled to the arm;
- a tool actuator coupled to the tool to move the tool relative to the arm;
- an arm valve coupled to the second pump and the arm actuator to receive hydraulic fluid under pressure from the second pump and selectively provide the hydraulic fluid to the arm actuator; and
- a tool valve coupled in parallel with the arm valve and to the tool actuator to receive hydraulic fluid under pressure from the second pump and selectively provide the hydraulic fluid to the tool actuator.
- 14. The excavator of claim 13 wherein the parallel-connected arm valve and tool valve are connected down stream of the boom valve such that hydraulic fluid from the first pump which is not diverted to the boom actuator is provided to the parallel-connected arm valve and tool valve.
- 15. The excavator of claim 9 and further comprising:
- an operator support portion coupled to the base;
- a hydraulic slew motor coupled to move the operator support portion relative to the base; and
- a slew valve coupled to the third pump and coupled upstream of the boost valve and in series with the boost valve and coupled to the slew motor to selectively provide hydraulic fluid from the third pump to the slew motor.
- 16. The excavator of claim 15 and further comprising:
- a boom offset cylinder coupled to the boom to pivot the boom relative to the base; and
- a boom offset valve coupled to the boom offset cylinder and coupled in parallel with the boost valve to selectively provide hydraulic fluid to the boom offset cylinder.
- 17. The excavator of claim 16 wherein the first and second traction valves, the boom valve, the arm valve and the bucket valve are all formed in a single physical valve stack.
- 18. An excavator, comprising:
- a base;
- a first drive mechanism coupled to the base;
- a first traction motor coupled to drive the first drive mechanism;
- a second drive mechanism coupled to the base;
- a second drive motor coupled to drive the second drive mechanism;
- a hydraulic power circuit including a first pump providing hydraulic fluid under pressure, a second pump providing hydraulic fluid under pressure, and a third pump providing hydraulic fluid under pressure; and
- a valve configuration coupled to the first, second and third pumps to selectively provide hydraulic fluid from the first pump to the first drive motor, from the second pump to the second drive motor and from the third pump to both the first and second drive motors.
- 19. The excavator of claim 18 wherein the first, second and third pumps each have a pump outlet providing the hydraulic fluid, and wherein the valve configuration comprises:
- a first traction valve having an inlet and an outlet, the inlet being operatively coupled to the first pump and the outlet being operatively coupled to the first drive motor to selectively provide the hydraulic fluid from the first pump to the first drive motor;
- a second traction valve having an inlet and an outlet, the inlet being operatively coupled to the second pump and the outlet being operatively coupled to the second drive motor to selectively provide the hydraulic fluid from the second pump to the second drive motor; and
- a boost valve having an inlet and an outlet, the inlet being operatively coupled to the third pump and the outlet being coupled for one-way fluid communication with the outlets of the first and second pumps to selectively provide the hydraulic fluid from the third pump to the first and second drive motors.
- 20. The excavator of claim 19 wherein the outlet of the boost valve is coupled for fluid communication with the outlets of the first and second pumps through first and second check valves, respectively.
REFERENCE TO CO-PENDING APPLICATION
This application is a continuation-in-part of application Ser. No. 08/623,168 filed Mar. 28, 1996, now abandoned, entitled MULTIFUNCTION VALVE STACK, and assigned to the same assignee as the present invention.
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Jun 1996 |
EPX |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
623168 |
Mar 1996 |
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