Back to results
US 2011/0079006 A1Published application
Method and apparatus for controlling a variable displacement hydraulic pump
AssigneeCaterpillar Inc.
InventorHongliu Du
Life of this patent
Estimating the term…
Abstract
A control system for a variable displacement hydraulic pump is disclosed. The control system utilizes two flow control valves to provide a flow of hydraulic fluid to two control actuators. The control actuators create opposing moments on the pump swashplate to control swashplate orientation and pump displacement.
Claims20
A hydraulic system comprising:
- a variable displacement hydraulic pump having a swashplate rotatable about an axis;
- a first hydraulic actuator configured to rotate the swashplate a first direction about the axis;
- a second hydraulic actuator configured to rotate the swashplate a second direction about the axis;
- the second direction being opposite to the first direction;
- a first flow control valve configured to provide pressurized fluid to the first actuator;
- and
- a second flow control valve configured to provide pressurized fluid to the second actuator.
4 more elements
A machine comprising:
- a engine;
- a variable displacement hydraulic pump powered by the engine and having a swashplate rotatable about an axis;
- a first hydraulic actuator configured to rotate the swashplate a first direction about the axis;
- a second hydraulic actuator configured to rotate the swashplate a second direction about the axis;
- the second direction being opposite to the first direction;
- a first flow control valve configured to provide pressurized fluid to the first actuator;
- and
- a second flow control valve configured to provide pressurized fluid to the second actuator.
5 more elements
A method for controlling an orientation of a swashplate of a variable displacement hydraulic device comprising the steps:
- Step 1:
- configuring the variable displacement hydraulic device to act as a pump by directing pressurized fluid through a first flow control valve to a first control actuator to create a moment in a first direction on the swashplate;
- and
- Step 2:
- configuring the variable displacement hydraulic device to act as a motor by directing pressurized fluid through a second flow control valve to a second control actuator to create a moment in a second direction on the swashplate, the second direction being opposite to the first direction.
2 more elements
Dependencies are inferred from the claim text.