Boom potential energy recovery of hydraulic excavator

• US 10,358,797 B2
• Filed: 08/15/2016
• Issued: 07/23/2019
• Est. Priority Date: 08/14/2015
• Status: Active Grant

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: Parker-Hannifin Corporation
• Inventors: White, Nicholas N., Howland, James, Zhang, Hao, Carl, Blake
• Primary Examiner(s): Lazo, Thomas E
• Application Number:
  US15/747,266
• Publication Number:
  US 20180216317A1
• Time in Patent Office: 1,072 Days
• 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 9/2225 using pressure-compensating valves
• CPC Class Codes: E02F 9/2267 Valves or distributors position of valves arrangements on upper-structures E02F9/0875
• CPC Class Codes: E02F 9/2271 Actuators and supports therefor and protection therefor
• 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 1/024 used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
• CPC Class Codes: F15B 13/021 Valves for interconnecting the fluid chambers of an actuator
• 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 2211/20546 variable capacity
• CPC Class Codes: F15B 2211/20576 with multiple pumps

Abstract

A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Claims

1. A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle, comprising:

first and second actuators configured to be coupled to the load implement for controlling raising and lowering of the load implement; and

control valving that is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power said one or more of the first and second actuators to raise the load implement;

wherein in the first position the control valving directs hydraulic fluid from a piston side of the other of the first and second actuators to rod sides of the first and second actuators to back fill the first and second actuators;

further comprising a proportional valve for controlling the amount of flow of hydraulic fluid from the piston side of the other actuator to the rod sides of the first and second actuators.

2. The hydraulic system of claim 1, wherein in the first position the control valving directs hydraulic fluid from only the one actuator to the accumulator to charge the accumulator.

3. The hydraulic system of claim 1, wherein in the second position the control valving directs hydraulic fluid from the accumulator to both the first and second actuators to power said first and second actuators to raise the load element.

4. The hydraulic system of claim 1, wherein in the second position the control valving (65) directs hydraulic fluid from the accumulator to only one of the first and second actuators to power said one of the first and second actuators to raise the load implement.

5. The hydraulic system of claim 1, further comprising a pump connected to the control valving, wherein in the second position the control valving (65) directs hydraulic fluid from the accumulator to one of the first and second actuators and directs hydraulic fluid from the pump to the other of the first and second actuators to raise the load implement.

6. The hydraulic system of claim 1, further comprising a metering valve disposed between the control valving and the accumulator, wherein when the control valving is in the first position the metering valve proportionately meters the hydraulic flow to control the rate of lowering the load implement and/or force on the load implement, and wherein when the control valving is in the second position the metering valve proportionately meters the hydraulic flow to control the rate of raising the load implement and/or force on the load implement.

7. The hydraulic system of claim 1, wherein in the first position the control valving directs hydraulic fluid from a piston side of the one actuator to the accumulator to charge the accumulator.

8. The hydraulic system of claim 1, wherein in the second position the control valving directs hydraulic fluid from the accumulator to piston sides of the one or more of the first and second actuators to raise the load implement.

9. The hydraulic system of claim 1, further comprising a pump connected to the control valving, wherein in the first position the control valving directs hydraulic fluid from the pump to rod sides of the first and second actuators to back fill the first and second actuators.

10. The hydraulic system of claim 1, further comprising a pump connected to the control valving, wherein in the second position the control valving directs hydraulic fluid from the pump to the first and second actuators to power the first and second actuators to raise the load implement.

11. The hydraulic system of claim 10, wherein the control valving combines the hydraulic fluid from the accumulator and the pump and directs the combined hydraulic fluid to the first and second actuators to power the first and second actuators to raise the load element.

12. The hydraulic system of claim 10, further comprising a second proportional valve configured to equalize pressure between the accumulator and the pump.

13. The hydraulic system of claim 1, wherein the load implement and control valving are part of a boom circuit, and further comprising a swing circuit and a valve, wherein the valve is configured to selectively share flow from the boom circuit to the swing circuit.

14. A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle, comprising:

an actuator configured to be coupled to the load implement for controlling raising and lowering of the load implement;

a hydraulic pressure transformer configured to transform a relatively lower-pressure/higher-flow hydraulic fluid received from the actuator to a relatively higher-pressure/lower-flow hydraulic fluid and to expel the higher-pressure/lower-flow hydraulic fluid to an accumulator to charge the accumulator; and

control valving that is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from the actuator to the hydraulic pressure transformer to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to the actuator to power the actuator to raise the load implement;

wherein the hydraulic pressure transformer includes a reciprocating linear actuator that has a relatively larger area chamber that receives the higher-pressure/lower-flow hydraulic fluid from the actuator and a relatively smaller area chamber from which the relatively higher-pressure/lower-flow hydraulic fluid is expelled to the accumulator.

15. The hydraulic system of claim 14, further comprising a prime mover pump connected to the control valving, and a flow passage that combines the hydraulic fluid from the accumulator and the prime mover pump and directs the combined hydraulic fluid to the actuator to power the actuator to raise the load implement.

16. The hydraulic system of claim 14, further comprising a prime mover pump connected to the control valving, wherein in the first position the control valving directs hydraulic fluid from the prime mover pump to a rod side of the actuator to back fill the actuator.

17. The hydraulic system of claim 14, wherein the load implement and control valving are part of a boom circuit, and further comprising a swing circuit and a valve, wherein the valve is configured to selectively share flow from the boom circuit to the swing circuit.

18. A method of recovering potential energy of a load implement of a mobile construction vehicle, comprising:

using first and second actuators configured to be coupled to the load implement to control raising and lowering of the load implement;

during a lowering of the load implement, directing hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and directing hydraulic fluid from a piston side of the other of the first and second actuators to rod sides of the first and second actuators to back fill the first and second actuators, including proportionally controlling the amount of flow of hydraulic fluid from the piston side of the other actuator to the rod sides of the first and second actuators; and

directing hydraulic fluid from the accumulator to one or more of the first and second actuators to power said one or more of the first and second actuators to raise the load implement.

19. The method of claim 18, further including, during the lowering of the load implement, directing the hydraulic fluid from only the one actuator to the accumulator to charge the accumulator.

20. The method of claim 18, further including directing the hydraulic fluid from the accumulator to both the first and second actuators to power said first and second actuators to raise the load element.