Meterless hydraulic system having flow sharing and combining functionality
AssigneeCaterpillar Inc.
InventorsPatrick Opdenbosch, Lawrence J. Tognetti, Bryan J. Hillman
Life of this patent
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Abstract
A hydraulic system includes a variable-displacement first pump, an over-center variable-displacement first travel motor selectively connected to receive fluid pressurized by the first pump in a closed loop manner, and an over-center variable-displacement second travel motor selectively connected to receive fluid pressurized by the first pump in parallel with the first travel motor in a closed loop manner. The hydraulic system also includes a linear actuator selectively connected to receive fluid pressurized by the first pump in parallel with the first and second travel motors in a closed loop manner.
Claims18
A hydraulic system comprising:
- a variable-displacement first pump;
- an over-center variable-displacement first travel motor selectively connected to receive fluid pressurized by the first pump in a closed loop manner;
- an over-center variable-displacement second travel motor selectively connected to receive fluid pressurized by the first pump in parallel with the first travel motor in a closed loop manner;
- a linear actuator selectively connected to receive fluid pressurized by the first pump in parallel with the first and second travel motors in a closed loop manner;
- at least one first isolation valve configured adjust a flow of the pressurized fluid from the first pump to the first travel motor;
- and
- at least one second isolation valve configured adjust a flow of the pressurized fluid from the first pump to the second travel motor.
A hydraulic system comprising:
- a variable-displacement first pump;
- a variable-displacement second pump;
- an over-center variable-displacement first travel motor selectively connected to receive fluid pressurized by the first pump in a closed loop manner;
- an over-center variable-displacement second travel motor selectively connected to receive fluid pressurized by the first pump in parallel with the first travel motor in a closed loop manner;
- a linear actuator selectively connected to receive fluid pressurized by the first pump in parallel with the first and second travel motors in a closed loop manner;
- a third motor selectively connected to receive fluid pressurized by the second pump in a closed loop manner;
- and
- at least one combiner device configured to selectively allow pressurized fluid from the first pump to combine with pressurized fluid from the second pump so that a combined flow from the first and second pumps is supplied to at least one of the first travel motor, the second travel motor, the third motor, and the linear actuator.
A method of operating a hydraulic system, the method comprising:
- pressurizing fluid with a first variable-displacement pump, the first pump being capable of simultaneously supplying pressurized fluid in parallel to an over-center variable-displacement first travel motor, an over-center variable-displacement second travel motor, and a linear actuator;
- selectively directing fluid pressurized by the first pump in parallel to at least two of the first travel motor, the second travel motor, or the linear actuator in a closed loop manner;
- returning the pressurized fluid to the first pump;
- pressurizing fluid with a second variable-displacement pump, the second pump being capable of simultaneously supplying pressurized fluid in parallel to the first travel motor, the second travel motor, the linear actuator, and a variable-displacement third, motor;
- and
- selectively directing fluid pressurized by the second pump in parallel to at least two of the first travel motor, the second travel motor, or the linear actuator in a closed loop manner via at least one combiner device.
Dependencies are inferred from the claim text.