Fluid-transfer system
AssigneeCaterpillar Inc.
InventorsJian YE, Zhenyu LI
Life of this patent
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Abstract
A fluid-transfer system includes a pump, a valve member for metering fluid pumped by the pump, and controls that regulate the position of the valve member. The controls may include an electric actuator operable to generate movement of the valve member in a first direction using activation current. The controls may also include one or more springs that provide resistance force that urges the valve member in a second direction, opposite the first direction. A spring rate of the resistance force may vary as a function of the position of the valve member in such a manner that a relationship between a flow rate of the fluid pumped through the pump and the activation current is more linear than a relationship between a position of the valve member and the activation current.
Claims20
A fluid-transfer system, comprising:
- a pump;
- a valve member for metering fluid pumped by the pump;
- controls that regulate the position of the valve member, including
- an electric actuator operable to generate movement of the valve member in a first direction using activation current;
- one or more springs that provide resistance force that urges the valve member in a second direction, opposite the first direction, wherein a spring rate of the resistance force varies as a function of the position of the valve member in such a manner that a relationship between a flow rate of the fluid pumped through the pump and the activation current is more linear than a relationship between a position of the valve member and the activation current.
A fluid-transfer system, comprising:
- a pump;
- a valve member for metering fluid pumped by the pump;
- controls that regulate the position of the valve member, including
- an electric actuator operable to generate movement of the valve member in a first direction using activation current, wherein a relationship between a position of the valve member in the first direction and a rate of flow of the pumped fluid is nonlinear;
- one or more springs that provide resistance force that urges the valve member in a second direction, opposite the first direction, wherein a spring rate of the resistance force varies as a function of the position of the valve member.
The fluid-transfer system of claim 13, wherein one or more of the plurality of springs contribute to the resistance force over only a portion of a range of travel of the valve member in the first direction.
A method of transferring fluid, the method comprising:
- pumping fluid with a pump;
- and
- metering the flow rate of the pumped fluid with a valve member, including controlling the position of the valve member at least in part by
- activating an electric actuator to urge the valve member in a first direction by supplying activation current to the electric actuator, and
- resisting movement of the valve member in the first direction with resistance force from one or more springs, including producing nonlinearity in a relationship between the position of the valve member and the activation current by varying a spring rate of the resistance force as a function of the position of the valve member.
Dependencies are inferred from the claim text.