Energy recapture system for hydraulic elevators

Patent metadata

Field	Value
Publication number	US-9605694-B2
Application number	US-201414576862-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 20, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

In a method of driving a hydraulic system, a contracting force is applied to a hydraulic actuator, thereby causing hydraulic fluid from the hydraulic actuator to flow through a first hydraulic pump motor into a first accumulator, thereby causing the first hydraulic pump motor to apply rotational energy to a shaft. The rotational energy from the shaft is applied to a second hydraulic pump motor, thereby causing hydraulic fluid to be pumped from a second accumulator to a third accumulator so as to store energy in the third accumulator. Once energy is stored in the third accumulator, the second hydraulic pump motor is driven with hydraulic fluid stored in the third accumulator so as to apply rotational energy to the shaft, thereby driving the first hydraulic pump motor to pump hydraulic fluid from the first accumulator to the hydraulic actuator, thereby applying an expanding force to the hydraulic actuator.

First claim

What is claimed is:

1. A hydraulic system, comprising:
(a) a hydraulic actuator;
(b) a first accumulator;
(c) a first hydraulic pump motor in fluid communication with the first accumulator and in fluid communication with the hydraulic actuator, the first hydraulic pump motor including a first shaft coupling, the first hydraulic pump motor being configurable as a motor in which rotational energy is applied to the first shaft coupling as a result of hydraulic fluid moving from the first accumulator into the hydraulic actuator, the first hydraulic pump motor also being configurable as a pump in which rotational energy received from the first shaft coupling causes hydraulic fluid to be pumped from the hydraulic actuator into the first accumulator;
(d) a shaft mechanically coupled to the first shaft coupling;
(e) a second accumulator;
(f) a third accumulator; and
(g) a second hydraulic pump motor in fluid communication with the third accumulator and in fluid communication with the second accumulator, the second hydraulic pump motor including a second shaft coupling mechanically coupled to the shaft, the second hydraulic pump motor being configurable as a pump in which rotational energy received from the second shaft coupling causes hydraulic fluid from the third accumulator to be pumped from the third accumulator into the second accumulator thereby storing energy in the second accumulator, the second hydraulic pump motor also being configurable as a motor in which rotational energy is applied to the second shaft coupling as a result of hydraulic fluid from the second accumulator moving into the third accumulator, thereby releasing energy stored in the second accumulator to be applied to the shaft.

2. The hydraulic system of claim 1 , wherein the first hydraulic pump motor comprises an axial piston variable displacement hydraulic pump motor.

3. The hydraulic system of claim 1 , wherein the second hydraulic pump motor comprises an axial piston variable displacement hydraulic pump motor.

4. The hydraulic system of claim 1 , further comprising a control system configured to adjust displacement of at least one of the first hydraulic pump motor and the second hydraulic pump motor so as to control a rate of hydraulic fluid transfer therethrough.

5. The hydraulic system of claim 1 , further comprising an auxiliary motor, configured to provide supplemental energy to a selected one of the first hydraulic pump motor and the second hydraulic pump motor via the shaft.

6. The hydraulic system of claim 5 , wherein the auxiliary motor comprises an electric motor.

7. The hydraulic system of claim 1 , further comprising a first two way directional check valve that couples the first accumulator to the first hydraulic actuator that is configured to prevent oscillations in the hydraulic fluid.

8. The hydraulic system of claim 1 , further comprising a second two way directional check valve that couples the second accumulator to the third accumulator that is configured to prevent oscillations in the hydraulic fluid.

9. The hydraulic system of claim 1 , further comprising an elevator cab that is coupled to the hydraulic actuator.

10. A hydraulic system, comprising:
(a) a hydraulic actuator;
(b) a first accumulator;
(c) a first hydraulic pump motor in fluid communication with the first accumulator and in fluid communication with the hydraulic actuator, the first hydraulic pump motor including a first shaft coupling, the first hydraulic pump motor being configurable as a motor in which rotational energy is applied to the first shaft coupling as a result of hydraulic fluid moving from the hydraulic actuator into the first accumulator as a result of a contracting force being applied to the hydraulic actuator, the first hydraulic pump motor also being configurable as a pump in which rotational energy received from the first shaft coupling causes hydraulic fluid to be pumped from the first accumulator into the hydraulic actuator thereby applying an expanding force to the hydraulic actuator;
(d) a shaft mechanically coupled to the first shaft coupling;
(e) a second accumulator;
(f) a third accumulator; and
(g) a second hydraulic pump motor in fluid communication with the third accumulator and in fluid communication with the second accumulator, the second hydraulic pump motor including a second shaft coupling mechanically coupled to the shaft, the second hydraulic pump motor being configurable as a pump in which rotational energy received from the second shaft coupling causes hydraulic fluid from the second accumulator to be pumped into the third accumulator thereby storing energy in the third accumulator, the second hydraulic pump motor also being configurable as a motor in which rotational energy is applied to the second shaft coupling as a result of hydraulic fluid from the third accumulator into the second accumulator, thereby releasing energy stored in the third accumulator to be applied to the shaft.

11. The hydraulic system of claim 10 , wherein the first hydraulic pump motor comprises an axial piston variable displacement hydraulic pump motor.

12. The hydraulic system of claim 10 , wherein the second hydraulic pump motor comprises an axial piston variable displacement hydraulic pump motor.

13. The hydraulic system of claim 10 , further comprising a control system configured to adjust displacement of at least one of the first hydraulic pump motor and the second hydraulic pump motor so as to control a rate of hydraulic fluid transfer therethrough.

14. The hydraulic system of claim 10 , further comprising an auxiliary motor, configured to provide supplemental energy to a selected one of the first hydraulic pump motor and the second hydraulic pump motor via the shaft.

15. The hydraulic system of claim 14 , wherein the auxiliary motor comprises an electric motor.

16. The hydraulic system of claim 10 , further comprising a first two way directional check valve that couples the first accumulator to the first hydraulic actuator that is configured to prevent oscillations in the hydraulic fluid.

17. The hydraulic system of claim 10 , further comprising a second two way directional check valve that couples the second accumulator to the third accumulator that is configured to prevent oscillations in the hydraulic fluid.

18. The hydraulic system of claim 10 , further comprising an elevator cab that is coupled to the hydraulic actuator.

19. A hydraulic transformer, comprising:
(a) a first hydraulic pump motor having a first primary port, a first secondary port, and a first shaft coupling, the first hydraulic pump motor being configurable as a motor in which rotational energy is applied to the first shaft coupling as a result of hydraulic fluid moving from a high pressure environment at the first primary port through the first secondary port to a low pressure environment, the first hydraulic pump motor also being configurable as a pump in which rotational energy received from the first shaft coupling causes hydraulic fluid to be pumped from a low pressure environment at the first secondary port out through the first primary port to a high pressure environment;
(b) a first shaft portion mechanically coupled to the first shaft coupling;
(c)
(d) a second shaft portion mechanically coupled to the first shaft portion;
(e) a second hydraulic pump motor having a second primary port, a second secondary port, and a second shaft coupling mechanically coupled to the second shaft portion, the second hydraulic pump motor being configurable as a pump in which rotational energy receive

Assignees

• Georgia Tech Res Inst

Inventors

• Leamy Michael J
• Pena Oscar Rafael

Classifications

• Y02B50/146

  Cross-Sectional Technologies · mapped topic

• Y02B50/148

  Cross-Sectional Technologies · mapped topic

• F15B1/02

  Installations or systems with accumulators · CPC title

• F15B21/14 Primary

  Energy-recuperation means · CPC title

• B66B1/04

  hydraulic · CPC title