Hydraulic regeneration system

• US 7,444,809 B2
• Filed: 01/30/2006
• Issued: 11/04/2008
• Est. Priority Date: 01/30/2006
• Status: Expired due to Fees

• Current Assignee: Caterpillar Sarl (Caterpillar Incorporated)
• Original Assignee: Caterpillar Incorporated, Shin Caterpillar Mitsubishi Ltd. (Caterpillar Incorporated)
• Inventors: Smith, David P., Mather, Daniel T.
• Primary Examiner(s): LOPEZ, FRANK D
• Application Number:
  US11/341,630
• Publication Number:
  US 20070186548A1
• Time in Patent Office: 1,009 Days
• Field of Search: 604/13, 604/14
• US Class Current: 60/414
• 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;

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;

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

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.

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

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

a fifth valve mechanism disposed between the accumulator and the first actuator, wherein the fourth and fifth 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 wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

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

5. 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.

6. 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.

7. The hydraulic system of claim 4, wherein the second actuator is configured to selectively expel fluid to the first actuator.

8. 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, 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;

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

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

a third 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.

9. The hydraulic system of claim 8, further including:

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

a fifth valve mechanism disposed between the accumulator and the first actuator, wherein the fourth and fifth 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.

10. The hydraulic system of claim 8, wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

11. The hydraulic system of claim 8, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

12. The hydraulic system of claim 8, 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.

13. The hydraulic, system of claim 12, wherein the second actuator is configured to selectively expel fluid to the first actuator.

14. 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;

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;

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

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.

15. The hydraulic system of claim 14, further including:

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

a fifth valve mechanism disposed between the accumulator and the first actuator, wherein the fourth and fifth 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.

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

17. The hydraulic system of claim 14, further including a transmission unit configured to receive fluid from and expel fluid to the accumulator.

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;

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;

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

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

a third 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.

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

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

a fifth valve mechanism disposed between the accumulator and the first actuator, wherein the fourth and fifth 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, wherein the energy recovery device includes a driving element and a driven element connected by a common shaft.

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

22. 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;

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

a tenth valve mechanism configured to fluidly communicate the first and third chambers;

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.

23. A 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;

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

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.

24. The machine of claim 23, further including:

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

a fifth valve mechanism disposed between the accumulator and the first actuator, wherein the fourth and fifth 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.

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

26. The machine of claim 23, 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.

27. The machine of claim 23, 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.