Hollow piston pump

Abstract

A positive displacement pump is provided. The pump comprises at least one piston operable to be powered by a power source and to pressurize a fluid. The at least one piston comprises an at least partially hollow piston wherein a flow of fluid is induced into and through the piston and a surrounding piston chamber. The piston preferably comprises a direct-mounted outlet valve for controlling a flow of fluid into and out of the piston.

What is claimed is: 
     
         1 . A fluid pump comprising:
 a housing having a fluid inlet, a fluid outlet, a crankcase, and a cylinder chamber having a predetermined diameter;   an elongated piston translatable within the cylinder chamber;   wherein the elongated piston is operable to be driven in a substantially reciprocating motion within the cylinder chamber;   wherein the elongated piston comprises a hollow portion and an aperture extending through a sidewall of the hollow portion of the elongated piston;   a first valve provided on an end of the elongated piston, wherein the first valve is operable to control a fluid flow between an internal volume of the hollow portion of the piston and an internal volume of the cylinder chamber; and   a second valve provided at an outlet of the cylinder chamber, wherein the second valve is operable to control a fluid flow between the internal volume of the cylinder chamber and the fluid outlet of the pump.   
     
     
         2 . The fluid pump of  claim 1 , wherein the fluid pump comprises a plurality of elongated pistons. 
     
     
         3 . The fluid pump of  claim 1 , wherein the first valve comprises a spring-loaded valve mounted to an end of the elongated piston. 
     
     
         4 . The fluid pump of  claim 1 , wherein the second valve comprises a spring-loaded valve. 
     
     
         5 . The fluid pump of  claim 1 , wherein the aperture of the elongated piston is provided within a fluid flow path. 
     
     
         6 . The fluid pump of  claim 1 , wherein the elongated piston comprises a second aperture extending through a sidewall of the elongated piston such that fluid is allowed to pass through the elongated piston. 
     
     
         7 . The fluid pump of  claim 1 , wherein the first valve comprises a biasing member, and wherein the first valve is operable to be provided in a closed position while the elongated piston is translated in a first direction and is operable to be provided in an open position while the elongated piston is provided in a second direction. 
     
     
         8 . A fluid pump comprising:
 a housing having a fluid inlet, a fluid outlet, and a cylinder chamber;   an elongated piston translatable within the cylinder chamber;   wherein the elongated piston is operable to be driven in a substantially reciprocating motion within the cylinder chamber;   wherein the elongated piston comprises a hollow portion and an aperture extending through a sidewall thereof, the aperture allowing for fluid to communicate with the hollow portion;   a valve provided on an end of the elongated piston, wherein the valve is operable to control a fluid flow to and from the hollow portion of the piston;   the valve comprising a biasing member that is operable to bias the valve toward a closed position.   
     
     
         9 . The fluid pump of  claim 8 , wherein the valve is operable to control a fluid flow between the hollow portion of the piston and an internal volume of the cylinder chamber. 
     
     
         10 . The fluid pump of  claim 8 , wherein the biasing member comprises a spring. 
     
     
         11 . The fluid pump of  claim 8 , wherein the fluid pump comprises a plurality of elongated pistons. 
     
     
         12 . The fluid pump of  claim 8 , wherein the valve comprises a cage valve mounted to the elongated piston. 
     
     
         13 . The fluid pump of  claim 8 , further comprising a second valve provided at an outlet of the cylinder chamber, wherein the second valve is operable to control a fluid flow between an internal volume of the cylinder chamber and the fluid outlet of the pump. 
     
     
         14 . The fluid pump of  claim 8 , wherein the aperture of the elongated piston is provided within a fluid flow path of the housing. 
     
     
         15 . The fluid pump of  claim 8 , wherein the elongated piston comprises a second aperture extending through a sidewall of the elongated piston. 
     
     
         16 . A fluid pump comprising:
 a housing having a fluid inlet, a fluid outlet, and a cylinder chamber;   an elongated piston translatable within the cylinder chamber;   wherein the elongated piston is operable to be driven in a substantially reciprocating motion within the cylinder chamber;   wherein the elongated piston comprises an internal volume having a hollow portion and an aperture extending through a sidewall thereof;   a valve provided on a distal end of the elongated piston, wherein the valve is operable to regulate a fluid flow between the cylinder chamber and the internal volume of the piston;   the valve comprising a biasing member that is operable to bias the valve toward a closed position, wherein fluid is not allowed to flow through the valve, and wherein the valve is operable to be provided in an open position when the elongated piston is provided in a suction state.   
     
     
         17 . The fluid pump of  claim 16 , wherein the fluid pump comprises a plurality of elongated pistons. 
     
     
         18 . The fluid pump of  claim 16 , wherein the valve comprises a cage valve mounted to the elongated piston. 
     
     
         19 . The fluid pump of  claim 16 , further comprising a second valve provided proximal to an outlet of the cylinder chamber, wherein the second valve is operable to control a fluid flow between an internal volume of the cylinder chamber and the fluid outlet of the pump. 
     
     
         20 . The fluid pump of  claim 16 , wherein the elongated piston comprises a second aperture extending through a sidewall of the elongated piston.