ENERGY MANAGEMENT SYSTEM FOR HEAVY EQUIPMENT

• US 20110233931A1
• Filed: 03/23/2010
• Published: 09/29/2011
• Est. Priority Date: 03/23/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Bucyrus International Incorporated (Caterpillar Incorporated)
• Inventors: Luvaas, John, WEBER, Robert, Helfrich, Joseph
• Granted Patent: US 8,362,629 B2
• Time in Patent Office: Days
• US Class Current: 290/7
• CPC Class Codes: E02F 9/2095 Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans control of hydraulic driven equipment E02F9/22
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: F04B 1/04 having cylinders in star- or fan-arrangement
• CPC Class Codes: F04B 17/03 driven by electric motors

Abstract

Equipment having an energy management system includes an articulated arm, a work implement, an energy management system, and a hydraulic circuit. The articulated arm includes hydraulic actuators designed to maneuver the articulated arm, and the work implement is fastened to the articulated arm. The energy management system is adjustable between a first configuration and a second configuration, and includes a hydraulic rotating machine and an electric rotating machine coupled to the hydraulic rotating machine. When the energy management system is in the first configuration, the hydraulic rotating machine and the electric rotating machine function as an electric motor powering a hydraulic pump. When the energy management system is in the second configuration, the hydraulic rotating machine and the electric rotating machine function as a hydraulic motor powering an electric generator. The hydraulic circuit is designed to supply a hydraulic fluid to drive the hydraulic actuators when the energy management system is in the first configuration, and is further designed to recover the hydraulic fluid from the hydraulic actuators and to generate electrical power when the energy management system is in the second configuration.

Claims

1. Equipment having an energy management system, comprising:

an articulated arm having hydraulic actuators configured to maneuver the articulated arm;

a work implement coupled to the articulated arm; and

an energy management system adjustable between a first configuration and a second configuration, wherein the energy management system comprises;

a hydraulic rotating machine, and

an electric rotating machine coupled to the hydraulic rotating machine,

wherein in the first configuration the hydraulic rotating machine and the electric rotating machine function as an electric motor powering a hydraulic pump, and

wherein in the second configuration the hydraulic rotating machine and the electric rotating machine function as a hydraulic motor powering an electric generator.

2. The equipment of claim 1, further comprising a hydraulic circuit configured to supply a hydraulic fluid to drive the hydraulic actuators when the energy management system is in the first configuration, and wherein the hydraulic circuit is further configured to recover the hydraulic fluid from the hydraulic actuators and to generate electrical power when the energy management system is in the second configuration.

3. The equipment of claim 2, wherein the hydraulic circuit comprises a cartridge valve system configured to direct the hydraulic fluid from the hydraulic rotating machine to the hydraulic actuators when the energy management system is in the first configuration, and to direct the hydraulic fluid from the hydraulic actuators to the hydraulic rotating machine when the energy management system is in the second configuration.

4. The equipment of claim 3, further comprising control circuitry configured to estimate a quantity of potential energy stored in the articulated arm and the work implement, and wherein the control circuitry is configured to change the direction of the hydraulic fluid through the cartridge valve system when the estimate exceeds a threshold value and the work implement is being lowered.

5. The equipment of claim 4, further comprising position measuring devices coupled to the hydraulic actuators, wherein the control circuitry is configured to use data from the position measuring devices to estimate the quantity of potential energy.

6. The equipment of claim 5, wherein the position measuring devices comprise linear position measuring devices.

7. The equipment of claim 4, further comprising angular position measuring devices coupled to joints of the articulated arm, wherein the control circuitry is configured to use data from the angular position measuring devices to estimate the quantity of potential energy.

8. The equipment of claim 7, wherein the angular position measuring devices comprise at least one of encoders or resolvers.

9. Equipment having an energy management system, comprising:

an articulated arm driven by one or more hydraulic actuators;

a sensor system coupled to the articulated arm;

a controller coupled to the sensor system, wherein data from the sensor system is used to produce an estimate of potential energy stored in the equipment;

a bi-directional valve, wherein the controller is configured to change a direction of a hydraulic fluid through the valve when the estimate exceeds a threshold value and the articulated arm is being lowered; and

an electric rotating machine coupled to a hydraulic rotating machine, wherein the electric rotating machine and the hydraulic rotating machine are configured to add energy to the hydraulic fluid, and to remove energy from the hydraulic fluid and generate electricity, depending upon the direction of the hydraulic fluid provided by the bi-directional valve.

10. The equipment of claim 9, wherein the sensor system comprises a linear position measuring device configured to sense a configuration of a hydraulic actuator used to maneuver the articulated arm.

11. The equipment of claim 9, wherein the sensor system comprises an angular position measuring device configured to sense a configuration of a joint of the articulated arm.

12. The equipment of claim 11, wherein the angular position measuring device comprises at least one of an encoder or a resolver.

13. The equipment of claim 9, wherein the bi-directional valve is a cartridge valve system.

14. Equipment having an energy management system, comprising:

an articulated arm driven by one or more hydraulic actuators;

a sensor system configured to detect a position of the articulated arm;

a controller coupled to the sensor system;

a bi-directional valve system, wherein the controller is configured to reverse a direction of a hydraulic fluid flowing through the valve system when the sensor system detects the articulated arm to be in a first position; and

a hydraulic rotating machine, wherein rotation of the hydraulic rotating machine in a first direction adds energy to the hydraulic fluid, and rotation of the hydraulic rotating machine in a second direction removes energy from the hydraulic fluid, and wherein the bi-directional valve system is configured to control the hydraulic fluid flowing to and from the hydraulic rotating machine.

15. The equipment of claim 14, further comprising an electrical rotating machine coupled to the hydraulic rotating machine and configured to power the hydraulic rotating machine, wherein rotation of the hydraulic rotating machine by the electrical rotating machine expends electricity, and rotation of the electrical rotating machine by the hydraulic rotating machine generates electricity.

16. The equipment of claim 15, further comprising an electrical generator and a combustion engine, the combustion engine configured to power the electrical generator and the electrical generator configured to supply electricity to the electrical rotating machine.

17. The equipment of claim 16, further comprising an electrical energy storage device, wherein the electrical energy storage device is configured to store electrical energy generated by the electrical rotating machine.

18. The equipment of claim 17, wherein the electrical energy storage device comprises at least one of a capacitor and a battery.

19. The equipment of claim 17, further comprising a torque feedback system coupled to the electrical rotating machine.

20. The equipment of claim 19, wherein data from the torque feedback system and data from the sensor system are used by the controller to provide an estimate of potential energy stored in the articulated arm, and wherein the estimate is used by the controller when determining whether to reverse the bi-directional valve system.