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US 9,068,578 B2Granted
Hydraulic system having flow combining capabilities
AssigneeCaterpillar Inc.
InventorPatrick Opdenbosch
Life of this patent
Estimating the term…
Abstract
A hydraulic system hydraulic system includes a variable displacement pump, and a variable displacement first travel motor selectively fluidly connected to the pump in a closed-loop manner. The system also includes a first switching valve associated with the first travel motor and configured to selectively switch a flow direction of fluid passing through the first travel motor from the pump. The system further includes a variable displacement second travel motor selectively fluidly connected to the pump in a closed-loop manner. The system also includes a second switching valve associated with the second travel motor and configured to selectively switch a flow direction of fluid passing through the second travel motor from the pump.
Claims12
A hydraulic system, comprising:
- a first variable displacement pump;
- a variable displacement first travel motor selectively fluidly connected to the first variable displacement pump in a closed-loop manner in a first hydraulic circuit;
- a first switching valve associated with the first travel motor and configured to selectively switch a flow direction of fluid passing through the first travel motor from the first variable displacement pump;
- a variable displacement second travel motor selectively fluidly connected to the first variable displacement pump in a closed-loop manner;
- a second switching valve associated with the second travel motor and configured to selectively switch a flow direction of fluid passing through the second travel motor from the first variable displacement pump,
- a linear actuator selectively fluidly connected to the first variable displacement pump in a closed-loop manner, and a third switching valve associated with the linear actuator, the third switching valve configured to change a speed of the linear actuator independent of the speed of the first and second travel motors, wherein the first variable displacement pump is configured to provide fluid to the first and second travel motors and the linear actuator simultaneously, and
- a second hydraulic circuit selectively fluidly connected to the first hydraulic circuit via at least one combining valve, the second hydraulic circuit including a second variable displacement pump, wherein the at least one combining valve is configured to direct fluid from the first and second pumps to the linear actuator.
4 more elements
A hydraulic system, comprising:
- a first hydraulic circuit, the first hydraulic circuit including
- a variable displacement first pump,
- a variable displacement first travel motor selectively fluidly connected to the first pump in a closed-loop manner,
- a first switching valve associated with the first travel motor and configured to change a speed of the first travel motor,
- a variable displacement second travel motor selectively fluidly connected to the first pump in a closed-loop manner, and
- a second switching valve associated with the second travel motor and configured to change a speed of the second travel motor independent of the speed of the first travel motor, wherein the first pump is configured to provide fluid to the first and second travel motors simultaneously,
- wherein the first hydraulic circuit further comprises
- a linear actuator selectively fluidly connected to the first pump in a closed-loop manner, and a third switching valve associated with the linear actuator, the third switching valve configured to change a speed of the linear actuator independent of the speed of the first and second travel motors, wherein the first pump is configured to provide fluid to the first and second travel motors and the linear actuator simultaneously, and
- further comprising a second hydraulic circuit selectively fluidly connected to the first hydraulic circuit via at least one combining valve, the second hydraulic circuit including a second variable displacement pump, wherein the at least one combining valve is configured to direct fluid from the first and second pumps to the linear actuator.
6 more elements
A method of controlling a hydraulic system, comprising:
- providing fluid to a variable displacement first travel motor in a closed loop manner with a variable displacement pump;
- simultaneously providing fluid to a variable displacement second travel motor in a closed loop manner with the pump;
- and
- changing a speed of the second travel motor independent of a speed of the first travel motor,
- providing fluid to a linear actuator in a closed loop manner with the pump, wherein the fluid is provided to the first and second travel motors and the linear actuator simultaneously,
- changing a speed of the linear actuator independent of the speeds of the first and second travel motors, and
- selectively providing fluid from a second pump in a second closed loop circuit to the linear actuator.
4 more elements
Dependencies are inferred from the claim text.