Patent ID: 6506030
Filing Date: 2003-01-14
Classification: F04B

Abstract:
A reciprocating pump for liquids, said pump comprising: a cylinder including outer walls providing a closed interior compartment having opposed ends, a piston assembly having a dispensing end and an opposed end, said piston assembly being movably mounted within said compartment for movement in opposed linear directions along the central axis of the piston assembly and cylinder between the opposed ends of the closed interior compartment, a sealing member between said piston assembly and said cylinder to maintain a dynamic fluid seal between the piston assembly and said cylinder as said piston assembly is moved in said opposed linear directions between said opposed ends of said closed interior compartment, said sealing member separating said interior compartment into a dispensing chamber and a reservoir chamber; said dispensing end of the piston assembly being kept in the dispensing chamber during movement of the piston assembly in said opposed linear directions, a linear magnetic drive including an armature on the piston assembly and a stator cooperating with the armature and providing a linearly moving magnetic field, a power supply for imparting a modulating electric current to the stator for generating a linearly moving magnetic field that imposes a magnetic force on the piston assembly in opposed linear directions through said armature for moving the piston assembly in said opposed linear directions; a valve-controlled inlet conduit communicating with the dispensing chamber of the interior compartment for directing liquid into the dispensing chamber to fill the volume of the dispensing chamber as the piston assembly moves through a swept volume in one linear direction through a liquid-receiving suction stroke; a valve-controlled outlet conduit communicating with the dispensing chamber of the interior compartment for directing pumped liquid out of the dispensing chamber as the piston assembly is moved through a swept volume in a direction opposed to said one linear direction through a liquid dispensing stroke, an energy storage and release media for storing energy as a result of the movement of the piston assembly through the suction stroke by the magnetic force imparted to the piston assembly by the linear magnetic drive in the direction of the suction stroke and for releasing the stored energy to said piston assembly as the piston assembly is moved through said dispensing stroke by the combined force provided by the release of the stored energy and by the magnetic force imparted to the piston assembly by the linear magnetic drive in the direction of the dispensing stroke.