Hydraulic regeneration system

• US 20070186548A1
• Filed: 01/30/2006
• Published: 08/16/2007
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Caterpillar Sarl (Caterpillar Incorporated)
• Original Assignee: CATERPILLAR INC. AND SHIN CATERPILLAR MITSUBISHI LTD.
• Inventors: Smith, David, Mather, Daniel
• Granted Patent: US 7,444,809 B2
• Time in Patent Office: Days
• US Class Current: 60/413
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: F15B 11/006 Hydraulic "Wheatstone bridge" circuits, i.e. with four nodes, P-A-T-B, and on-off or proportional valves in each link
• CPC Class Codes: F15B 21/14 Energy-recuperation means
• CPC Class Codes: F15B 2211/20523 Internal combustion engine
• CPC Class Codes: F15B 2211/30575 in a Wheatstone Bridge arrangement (also half bridges)
• CPC Class Codes: F15B 2211/625 Accumulators
• CPC Class Codes: F15B 2211/7053 Double-acting output members
• CPC Class Codes: F15B 2211/88 Control measures for saving energy

Abstract

A hydraulic system for a work machine is provided. The hydraulic regeneration system has a tank, a primary source, a first actuator, an accumulator, and a first valve mechanism. The tank is configured to hold a supply of fluid. The primary source is configured to pressurize the fluid and has a suction inlet and a discharge outlet. The first actuator is configured to receive pressurized fluid from the discharge outlet of the primary source. The accumulator is in fluid communication with the tank, the suction inlet of the primary source, and the first actuator. The first valve mechanism is disposed between the suction inlet of the primary source and the accumulator, and is movable between a first position at which fluid returning from the first actuator is directed to the suction inlet of the primary source, and a second position at which fluid returning from the first actuator is directed to only the accumulator.

Claims

1. A hydraulic system, comprising:

a tank configured to hold a supply of fluid;

a primary source configured to pressurize the fluid and having a suction inlet and a discharge outlet;

a first actuator configured to receive pressurized fluid from the discharge outlet of the primary source;

an accumulator in fluid communication with the tank, the suction inlet of the primary source, and the first actuator; and

a first valve mechanism disposed between the suction inlet of the primary source and the accumulator, wherein the valve mechanism is movable between a first position at which fluid returning from the first actuator is directed to the suction inlet of the primary source, and a second position at which fluid returning from the first actuator is directed to only the accumulator.

2. The hydraulic system of claim 1, further including:

a second valve mechanism disposed between the accumulator and the first actuator; and

a third valve mechanism disposed between the accumulator and the first actuator, wherein the second and third valve mechanisms are configured to allow fluid to flow from the first actuator to the accumulator and from the accumulator to the first actuator during a ride control mode of operation.

3. The hydraulic system of claim 1, further including an energy recovery device in fluid communication with the first actuator, the accumulator, and the primary source.

4. The hydraulic system of claim 3, further including:

a second valve mechanism disposed between the energy recovery device and the accumulator and first actuator; and

a third valve mechanism disposed between the suction inlet of the primary source and the energy recovery device, wherein the accumulator is selectively fluidly communicated with the suction inlet of the primary source at a location between the third valve mechanism and the suction inlet of the primary source.

5. The hydraulic system of claim 3, wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

6. The hydraulic system of claim 1, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

7. The hydraulic system of claim 1, wherein fluid from the first actuator is directed to the accumulator simultaneous to the direction of pressurized fluid from the primary source to the first actuator.

8. The hydraulic system of claim 1, further including a second actuator in communication with the tank, the primary source, the first actuator, and the accumulator, wherein the first actuator is configured to receive pressurized fluid from the primary source and simultaneously expel pressurized fluid to the second actuator.

9. The hydraulic system of claim 8, wherein the second actuator is configured to selectively expel fluid to the first actuator.

10. A hydraulic system, comprising:

a tank configured to hold a supply of fluid;

a primary source configured to pressurize the fluid and having a suction inlet and a discharge outlet;

a first actuator configured to receive pressurized fluid from the discharge outlet of the primary source; and

an accumulator in fluid communication with the tank, the suction inlet of the primary source, and the first actuator, wherein fluid from the first actuator is directed to the accumulator simultaneous to the direction of pressurized fluid from the primary source to the first actuator.

11. The hydraulic system of claim 10, further including:

a second valve mechanism disposed between the accumulator and the first actuator; and

a third valve mechanism disposed between the accumulator and the first actuator, wherein the second and third valve mechanisms are configured to allow fluid to flow from the first actuator to the accumulator and from the accumulator to the first actuator during a ride control mode of operation.

12. The hydraulic system of claim 10, further including an energy recovery device in fluid communication with the first actuator, the accumulator, and the suction inlet of the primary source.

13. The hydraulic system of claim 12, further including:

a second valve mechanism disposed between the energy recovery device and the accumulator and first actuator; and

a third valve mechanism disposed between the suction inlet of the primary source and the energy recovery device, wherein the accumulator is selectively fluidly communicated with the suction inlet of the primary source at a location between the third valve mechanism and the suction inlet of the primary source.

14. The hydraulic system of claim 12, wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

15. The hydraulic system of claim 10, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

16. The hydraulic system of claim 10, further including a second actuator in communication with the tank, the primary source, the first actuator, and the accumulator, wherein the first actuator is configured to receive pressurized fluid from the primary source and simultaneously expel pressurized fluid to the second actuator.

17. The hydraulic, system of claim 16, wherein the second actuator is configured to selectively expel fluid to the first actuator.

18. A hydraulic system, comprising:

a tank configured to hold a supply of fluid;

a primary source configured to pressurize the fluid;

a first actuator in communication with the tank and the primary source; and

a second actuator in communication with the tank, the primary source, and the first actuator, wherein the first actuator is configured to receive pressurized fluid from the primary source and simultaneously expel pressurized fluid to the second actuator.

19. The hydraulic system of claim 18, further including:

a second valve mechanism disposed between the accumulator and the first actuator; and

a third valve mechanism disposed between the accumulator and the first actuator, wherein the second and third valve mechanisms are configured to allow fluid to flow from the first actuator to the accumulator and from the accumulator to the first actuator during a ride control mode of operation.

20. The hydraulic system of claim 18, further including an energy recovery device in fluid communication with the first actuator, the accumulator, and the primary source.

21. The hydraulic system of claim 20, further including:

a second valve mechanism disposed between the energy recovery device and the accumulator and first actuator; and

a third valve mechanism disposed between the primary source and the energy recovery device, wherein the accumulator is selectively fluidly communicated with the primary source at a location between the third valve mechanism and the primary source.

22. The hydraulic system of claim 20, wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

23. The hydraulic system of claim 18, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

24. The hydraulic system of claim 18, wherein the second actuator is configured to selectively expel fluid to the first actuator.

25. A hydraulic system, comprising:

a tank configured to hold a supply of fluid;

a primary source configured to pressurize the fluid;

a first actuator in communication with the tank and the primary source; and

a second actuator in communication with the tank, the primary source, and the first actuator, wherein the first actuator is configured to selectively expel fluid to the second actuator, and the second actuator is configured to selectively expel fluid to the first actuator.

26. The hydraulic system of claim 25, further including:

a second valve mechanism disposed between the accumulator and the first actuator; and

a third valve mechanism disposed between the accumulator and the first actuator, wherein the second and third valve mechanisms are configured to allow fluid to flow from the first actuator to the accumulator and from the accumulator to the first actuator during a ride control mode of operation.

27. The hydraulic system of claim 25, further including an energy recovery device in fluid communication with the first actuator, the accumulator, and the primary source.

28. The hydraulic system of claim 27, further including:

a second valve mechanism disposed between the energy recovery device and the accumulator and first actuator; and

a third valve mechanism disposed between the primary source and the energy recovery device, wherein the accumulator is selectively fluidly communicated with the primary source at a location between the third valve mechanism and the primary source.

29. The hydraulic system of claim 27, wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

30. The hydraulic system of claim 25, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

31. A hydraulic system, comprising:

a tank configured to hold a supply of fluid;

a primary source configured to pressurize the fluid;

a first actuator in communication with the tank and the primary source, the first actuator having a first chamber and a second chamber;

a second actuator in communication with the tank, the primary source, and the first actuator, the second actuator having a third chamber and a fourth chamber;

a first valve mechanism configured to fluidly communicate the primary source and the first chamber;

a second valve mechanism configured to fluidly communicate the primary source and the second chamber;

a third valve mechanism configured to fluidly communicate the first chamber and the tank;

a fourth valve mechanism configured to fluidly communicate the second chamber and the tank;

a fifth valve mechanism configured to fluidly communicate the primary source and the third chamber;

a sixth valve mechanism configured to fluidly communicate the primary source and the fourth chamber;

a seventh valve mechanism configured to fluidly communicate the third chamber and the tank;

an eight valve mechanism configured to fluidly communicate the fourth chamber and the tank; and

a ninth valve mechanism configured to fluidly communicate the second and fourth chambers.

32. The hydraulic system of claim 31, further including a tenth valve mechanism configured to fluidly communicate the first and third chambers.

33. The hydraulic system of claim 32, further including:

an accumulator;

an eleventh valve mechanism disposed between the first chamber and the accumulator;

a twelfth valve mechanism disposed between the third chamber and the accumulator; and

a thirteenth valve mechanism disposed between the accumulator and the primary source.

34. A method of operating a hydraulic system, comprising:

pressurizing a fluid;

directing the pressurized fluid to first actuator;

selectively directing fluid from the first actuator to a source of the pressurized fluid; and

selectively directing fluid from the first actuator to only an accumulator.

35. The method of claim 34, further including directing fluid from the accumulator to the first actuator during a ride control mode of operation.

36. The method of claim 34, further including selectively directing fluid from the first actuator, the accumulator, and the source of the pressurized fluid to an energy recovery device.

37. The method of claim 34, further including:

directing fluid from a transmission unit to the accumulator; and

directing fluid from the accumulator to the transmission unit.

38. The method of claim 34, further including directing fluid from the first actuator to the accumulator simultaneous to the direction of pressurized fluid from the source of pressurized fluid to the first actuator.

39. The method of claim 34, further including expelling pressurized fluid from the first actuator to a second actuator simultaneous to the directing of fluid from the source of pressurized fluid to the first actuator.

40. The method of claim 39, further including expelling pressurized fluid from the second actuator to the first actuator.

41. A work machine, comprising:

a power source configured to produce a power output;

a traction device operatively driven by the power source;

a work tool;

a tank configured to hold a supply of fluid;

a primary source driven by the power source to pressurize the fluid and having a suction inlet and a discharge outlet;

a first actuator operatively connected to move the work tool and configured to receive pressurized fluid from the discharge outlet of the primary source;

an accumulator in fluid communication with the tank, the suction inlet of the primary source, and the first actuator;

a first valve mechanism disposed between the suction inlet of the primary source and the accumulator, wherein the valve mechanism is movable between a first position at which fluid returning from the first actuator is directed to the suction inlet of the primary source, and a second position at which fluid returning from the first actuator is directed to only the accumulator; and

an energy recovery device in fluid communication with the first actuator, the accumulator, and the primary source.

42. The work machine of claim 41, further including:

a second valve mechanism disposed between the accumulator and the first actuator; and

a third valve mechanism disposed between the accumulator and the first actuator, wherein the second and third valve mechanisms are configured to allow fluid to flow from the first actuator to the accumulator and from the accumulator to the first actuator during a ride control mode of operation.

43. The work machine of claim 41, further including:

a second valve mechanism disposed between the energy recovery device and the accumulator and first actuator; and

a third valve mechanism disposed between the suction inlet of the primary source and the energy recovery device, wherein;

the accumulator is selectively fluidly communicated with the suction inlet of the primary source at a location between the third valve mechanism and the suction inlet of the primary source; and

the energy recovery device includes a driving element and a driven element connected by a common shaft.

44. The work machine of claim 41, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

45. The work machine of claim 41, wherein fluid from the first actuator is directed to the accumulator simultaneous to the direction of pressurized fluid from the primary source to the first actuator.

46. The work machine of claim 41, further including a second actuator in communication with the tank, the primary source, the first actuator, and the accumulator, wherein:

the first actuator is configured to receive pressurized fluid from the primary source and simultaneously expel pressurized fluid to the second actuator; and

the second actuator is configured to selectively expel fluid to the first actuator.