Seal-less piston pump for liquefied gas

摘要

A fuel supply system for a vehicle uses a seal-less piston LPG injunction pump which pumps fluid from a storage tank to an engine. The pump uses the vehicle's pneumatic air system, wherein the pressurized air of this system alternatingly drives an actuator magnetically coupled to a piston.

主权项

1. A piston pump for a fluid, comprising:
a housing unit comprising an enclosed, tubular pump housing, which is formed as a pump tube having a tube wall that internally defines an inner pump bore; a piston wholly contained within said inner pump bore wherein said piston subdivides said inner pump bore into first and second piston chambers, said piston being reversibly movable within said inner pump bore in a reversible pumping direction so as to alternatingly expand and contract respective first and second volumes of said first and second piston chambers during piston movement; a main body located outside of said pump housing, wherein said main body is reversibly movable along said pump housing and is magnetically coupled to said piston through said tube wall solely by a magnetic attraction between said main body and said piston, a drive actuator located on said housing unit externally of said pump housing, said drive actuator being operatively connected to said main body to effect reciprocating movement of said main body along said pump housing with said piston moving with said main body within said inner bore to vary said respective first and second volumes; and said housing unit including inlet and outlet passages for supplying an inlet fluid to an expanding one of said first and second pump chambers and receiving a pressurized fluid from a contracting one of said first and second pump chambers, said housing unit including first and second end caps which include pump housing bores that sealingly seat opposite ends of said pump housing therein, said first and second end caps including said inlet and outlet passages therein which communicate with said first and second pump chambers through said pump housing bores, said housing unit including a plurality of guide tubes extending along and parallel to said pump tube, said main body being slidably supported on said guide tubes so as to reciprocate along said pump tube and said guide tubes having opposite ends seated within guide tube bores formed in said end caps, said guide tubes being hollow and disposed in fluid communication with said said inlet and outlet passages.