Actuator control system and method

• US 7,621,123 B2
• Filed: 01/19/2007
• Issued: 11/24/2009
• Est. Priority Date: 01/20/2006
• Status: Expired due to Fees

• Current Assignee: Allen L. Rasmussen, Kenneth Sean Cowan, Michael Harry Jacobs
• Original Assignee: Allen L. Rasmussen, Kenneth Sean Cowan, Michael Harry Jacobs
• Inventors: Rasmussen, Allen L., Cowan, Kenneth Sean, Jacobs, Michael H.
• Primary Examiner(s): Lazo; Thomas E
• Application Number:
  US11/655,684
• Publication Number:
  US 20070204603A1
• Time in Patent Office: 1,040 Days
• Field of Search: 604/28, 604/31
• US Class Current: 60/428
• CPC Class Codes: F15B 21/087 Control strategy, e.g. with block diagram
• CPC Class Codes: F15B 2211/20515 Electric motor
• CPC Class Codes: F15B 2211/20538 constant capacity
• CPC Class Codes: F15B 2211/633 representing a state of the prime mover, e.g. torque or rotational speed
• CPC Class Codes: F15B 2211/6655 Power control, e.g. combined pressure and flow rate control
• CPC Class Codes: F15B 2211/6656 Closed loop control, i.e. control using feedback
• CPC Class Codes: F15B 2211/7053 Double-acting output members
• CPC Class Codes: F15B 2211/7058 Rotary output members

Abstract

Actuator control system and method comprising an electric motor driving a hydraulic pump in fluid delivery communication with a source of hydraulic fluid; a variable speed controller operatively coupled to the motor for driving the pump at variable speeds; an external hydraulic actuator in fluid delivery communication with the pump for receiving pressurized fluid flow from the pump; and a feedback loop operatively coupled from the motor to the controller for providing feedback signals correlative to a pressure of the pressurized fluid flow through the driven pump for driving the external hydraulic actuator in response to the feedback signals for providing electronic velocity and force control of actuation of the external hydraulic actuator. The actuator control system and method can operate on one or many high-pressure hydraulic linear and/or rotary actuators on different pieces of hydraulically driven equipment and with different velocity requirements actuating in different directions.

Claims

1. An actuator control system, comprising:

a source of hydraulic fluid;

a pump in fluid delivery communication with said source of hydraulic fluid;

an electric motor operatively coupled to said pump for driving said pump for supplying a pressured fluid flow of hydraulic fluid from said source of hydraulic fluid;

a solenoid operated directional valve in fluid delivery communication with said pump for receiving said pressurized fluid flow of hydraulic fluid supplied from said pump and allowing said pressurized fluid flow through said solenoid operated directional valve upon operation thereof;

a hydraulic actuator in fluid delivery communication with said pressurized fluid flow through said solenoid operated directional valve for moving a member of said hydraulic actuator at a velocity and force upon operation of said solenoid operated directional valve, wherein said hydraulic actuator is a rotary actuator and said member is a rotary member;

a variable speed controller operatively coupled to said electric motor; and

a motor feedback loop operatively coupled from said electric motor to said variable speed controller for providing feedback signals correlative to a pressure of said pressurized fluid flow for driving said member of said hydraulic actuator in response to said feedback signals for providing electronic velocity and force control of actuation of said member of said hydraulic actuator.

2. An actuator control system, comprising:

a reservoir of hydraulic fluid providing a source of hydraulic fluid;

a pump mounted in fluid delivery communication with said source of hydraulic fluid;

an electric motor operatively coupled to said pump for driving said pump for supplying a pressurized flow of hydraulic fluid from said source of hydraulic fluid;

a variable speed controller operatively coupled to said electric motor for driving said electric motor at variable speeds;

a hydraulic actuator in fluid delivery communication with said pump for receiving said pressurized flow of hydraulic fluid from said pump, wherein said hydraulic actuator is a rotary actuator;

a feedback loop operatively coupled from said electric motor to said variable speed controller for providing feedback signals from said motor to said variable speed controller for intermittently driving said motor between a first low torque and high velocity state in response to said feedback signals being correlative to a low load being placed on said hydraulic actuator and a second high torque and low velocity state in response to said feedback signals being correlative to a high load condition being placed on said hydraulic actuator;

a common enclosure enclosing said reservoir, said pump, said electric motor, said variable speed motor controller, and said feedback loop within said common enclosure; and

wherein said hydraulic actuator is external to said common enclosure.