Energy recovery system having integrated boom/swing circuits

• US 9,290,912 B2
• Filed: 10/31/2012
• Issued: 03/22/2016
• Est. Priority Date: 10/31/2012
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Wen, Gang Victor, Ma, Pengfei, Zhang, Jiao, Shang, Tonglin
• Primary Examiner(s): Leslie, Michael
• Application Number:
  US13/665,384
• Publication Number:
  US 20140119867A1
• Time in Patent Office: 1,238 Days
• Field of Search: 604/13, 604/14, 604/21, 604/22
• US Class Current: 1/1
• CPC Class Codes: E02F 9/123 Drives or control devices specially adapted therefor E02F9/125 and E02F9/128 take precedence
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2242 including an electronic controller
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: F15B 1/027 having accumulator charging devices
• CPC Class Codes: F15B 1/0275 with two or more pilot valves, e.g. for independent setting of the cut-in and cut-out pressures
• CPC Class Codes: F15B 11/17 using two or more pumps
• CPC Class Codes: F15B 13/06 for use with two or more servomotors
• CPC Class Codes: F15B 21/14 Energy-recuperation means
• CPC Class Codes: F15B 2211/20576 with multiple pumps
• CPC Class Codes: F15B 2211/212 the pressure sources being accumulators
• CPC Class Codes: F15B 2211/6306 representing a pressure
• CPC Class Codes: F15B 2211/6313 the pressure being a load pressure
• CPC Class Codes: F15B 2211/7058 Rotary output members
• CPC Class Codes: F15B 2211/7135 Combinations of output members of different types, e.g. single-acting cylinders with rotary motors

Abstract

An energy recovery system for a machine is disclosed. The energy recovery system may have a boom circuit with at least a one linear actuator configured to move a work tool, and a boom accumulator configured to selectively collect pressurized fluid from the at least one linear actuator and to discharge pressurized fluid back to the at least one linear actuator. The energy recovery system may also have a swing circuit with a swing motor configured to move the work tool, and a swing accumulator configured to selectively collect pressurized fluid from the swing motor and discharge pressurized fluid back to the swing motor. The energy recovery system may further have a common accumulator passage fluidly connecting the boom accumulator and the swing accumulator.

Claims

1. An energy recovery system, comprising:

a boom circuit having;

at least a one linear actuator configured to move a work tool; and

a boom accumulator configured to selectively collect pressurized fluid from the at least one linear actuator;

a swing circuit having;

a swing motor configured to move the work tool; and

a swing accumulator configured to selectively collect pressurized fluid from the swing motor and discharge pressurized fluid back to the swing motor;

a common accumulator passage fluidly connecting the boom accumulator and the swing accumulator; and

a common accumulator disposed in fluid communication with the common accumulator passage.

2. The energy recovery system of claim 1, wherein:

the boom circuit further has;

a tank;

a first pump configured to draw fluid from the tank and pressurize the fluid; and

at least a first control valve movable to selectively direct pressurized fluid from the first pump to the at least one linear actuator and from the at least one linear actuator to the tank; and

the energy recovery system further includes a motor selectively driven by fluid discharged from the boom accumulator and the swing accumulator to power the first pump.

3. The energy recovery system of claim 2, wherein the first pump is engine driven, and the motor is further configured to selectively power an engine that drives the first pump.

4. The energy recovery system of claim 2, wherein:

the swing circuit further has;

a second pump configured to draw fluid from the tank and pressurize the fluid; and

at least a second control valve movable to selectively direct pressurized fluid from the second pump to the swing motor and from the swing motor to the tank; and

the motor is configured to power only the first pump.

5. The energy recovery system of claim 4, further including a control valve disposed within the common accumulator passage and selectively movable from a flow-blocking position against a spring bias toward a flow-passing position.

6. The energy recovery system of claim 5, wherein:

the boom accumulator and motor are connected to the common accumulator passage to receive fluid from the swing accumulator in parallel;

the control valve is a first control valve disposed between the swing accumulator and both of the boom accumulator and the motor; and

the energy recovery system further includes a second control valve disposed between the boom accumulator and both of the motor and the first control valve, the second control valve being movable from a flow-blocking position against a spring bias toward a flow-passing position.

7. The energy recovery system of claim 4, further including:

a common low-pressure passage connecting the at least a first control valve with the at least a second control valve and a makeup valve of the motor; and

a makeup accumulator fluidly connected to the common low-pressure passage.

8. The energy recovery system of claim 7, further including a pressure relief valve selectively fluidly connecting the common low-pressure passage with the tank.

9. The energy recovery system of claim 7, wherein the common low-pressure passage is further connected to a makeup valve of the swing motor.

10. The energy recovery system of claim 7, further including:

a common high-pressure passage fluidly connecting an output of the first pump with an outlet of the second pump; and

a combiner valve disposed within the common high-pressure passage.

11. The energy recovery system of claim 10, further including a pressure compensator disposed downstream of the common high-pressure passage and the first pump, and upstream of the at least a first control valve.

12. The energy recovery system of claim 4, further including:

a return passage extending from an outlet of the motor to the common accumulator passage; and

an outlet control valve disposed within the return passage and movable from a first position at which the outlet of the motor is fluidly connected to the tank, against a spring bias toward a second position at which the outlet of the motor is fluidly connected to the common accumulator passage.

13. The energy recovery system of claim 12, further including a pressure relief valve associated with the outlet of the motor.

14. The energy recovery system of claim 1, further including:

a first control valve disposed between the swing accumulator and the common accumulator; and

a second control valve disposed between the boom accumulator and the common accumulator.

15. A method of recovering energy, comprising:

directing pressurized fluid into a linear actuator to move a work tool;

storing pressurized fluid from the linear actuator in a boom accumulator;

directing pressurized fluid into a swing motor to move the work tool;

storing pressurized fluid from the linear actuator in a swing accumulator; and

selectively communicating the boom and swing accumulators via a common accumulator disposed in fluid communication with a common accumulator passage fluidly connecting the boom and swing accumulators.

16. The method of claim 15, further including selectively directing stored pressurized fluid from the boom and swing accumulators through a motor to drive a boom pump.

17. The method of claim 16, further including selectively directing stored pressurized fluid from the boom and swing accumulators through a motor to drive an engine.

18. The method of claim 17, wherein directing stored pressurized fluid from the swing accumulator through the motor includes directing stored pressurized fluid from the swing accumulator into a common accumulator and from the common accumulator through the motor.

19. A machine, comprising:

an undercarriage;

a boom pivotally connected to the undercarriage;

a work tool operatively connected to the boom;

a swing motor configured to swing the boom and work tool;

a pair of linear actuators configured to lift the boom and work tool;

a boom accumulator configured to selectively collect pressurized fluid from the pair of linear actuators;

a swing accumulator configured to selectively collect pressurized fluid from the swing motor and discharge pressurized fluid back to the swing motor;

a common accumulator passage fluidly connecting the boom accumulator and the swing accumulator;

a common accumulator disposed in fluid communication with the common accumulator passage;

a tank;

a pump configured to draw fluid from the tank and pressurize the fluid;

at least a first control valve movable to selectively direct pressurized fluid from the pump to the pair of linear actuators and from the pair of linear actuators to the tank;

a motor selectively driven by fluid discharged from the boom accumulator and the swing accumulator to power the pump; and

a return passage extending from an outlet of the motor to the common accumulator passage.