Pump utilizing dissimilar materials to compensate for temperature change
AssigneeCaterpillar Inc.
InventorBryan E. Nelson
Life of this patent
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Abstract
A pump includes a pump housing that defines an inlet and an outlet. Within the pump housing, there is a barrel that is adjacent to at least one reciprocating piston. A sleeve surrounds the annular outer surface of the piston and is movable. The temperature change within the pump is compensated for by making at least one of the sleeve and the barrel of a material with a lower coefficient of thermal expansion than the material of the piston. A clearance defined by an inner surface of the sleeve and the annular outer surface of the piston increases when the temperature is low and decreases when the temperature is high.
Claims19
A pump comprising:
- a pump housing defining an inlet and an outlet;
- a barrel at least partially positioned in the housing;
- at least one piston that reciprocates in the pump housing and is positioned at least partially in the barrel;
- a sleeve surrounding an annular outer surface of each piston and being movable;
- and
- the sleeve being comprised of a material with a lower coefficient of thermal expansion than a material comprising the piston.
A method of compensating for temperature change within a pump comprising the steps of:
- increasing a clearance between an annular outer surface of a piston and at least one of an inner surface of a sleeve and a barrel when a temperature within the pump is low;
- and
- decreasing the clearance between the annular outer surface of the piston and at least one of an inner surface of the sleeve and the barrel when the temperature within the pump is high.
A sleeve metered pump comprising:
- a pump housing defining an inlet and an outlet;
- a barrel at least partially positioned in the housing;
- at least one piston that reciprocates in the pump housing and is positioned at least partially in the barrel;
- a sleeve surrounding each piston at a position between opposite ends of the piston, and being movable with respect to the barrel;
- and
- said sleeve being comprised of a material with a lower coefficient of thermal expansion than a material comprising the piston.
Dependencies are inferred from the claim text.