Cylinder pump systems and methods for pumping and measuring fluids

Abstract

Cylinder pump systems and methods for pumping and measuring fluids are provided. The pump system includes a piston cylinder pump, a linear actuator, and a motor assembly. The piston cylinder pump includes a piston located within a cavity of a cylinder body and dividing the cavity into a first adjustable chamber and a second adjustable chamber and a rod coupled to the piston. The linear actuator includes a shaft coupled to the rod and the linear actuator converts rotational motion to linear motion to linearly move the rod. The motor assembly is coupled to the linear actuator and operable to drive the linear actuator.

What is claimed is: 
     
         1 . A pump system, comprising:
 a piston cylinder pump comprising a piston located within a cavity of a cylinder body and dividing the cavity into a first adjustable chamber and a second adjustable chamber and a rod coupled to the piston;   a linear actuator comprising a shaft coupled to the rod, wherein the linear actuator converts rotational motion to linear motion to linearly move the rod; and   a motor assembly coupled to the linear actuator and operable to drive the linear actuator.   
     
     
         2 . The pump system of  claim 1 , wherein:
 the piston comprises a first side opposite a second side;   the rod is coupled to the first side of the piston;   the first adjustable chamber is located between the first side of the piston and a first inner surface of the cylinder body; and   the second adjustable chamber is located between the second side of the piston and a second inner surface of the cylinder body.   
     
     
         3 . The pump system of  claim 2 , wherein the piston is linearly moveable away from the linear actuator during a first stroke at a first stroke speed and linearly moveable toward the linear actuator during a second stroke at a second stroke speed, wherein the second stroke speed is greater than the first stroke speed. 
     
     
         4 . The pump system of  claim 3 , wherein:
 the first adjustable chamber has a first minimum volume at a start of the first stroke;   the second adjustable chamber has a second minimum volume at a start of the second stroke, and   the first minimum volume is less than the second minimum volume.   
     
     
         5 . The pump system of  claim 3 , further comprising a first port in fluid communication with the first adjustable chamber, a second port in fluid communication with the second adjustable chamber, and wherein the first port and the second port discharge a fluid at substantially the same flowrate. 
     
     
         6 . The pump system of  claim 1 , further comprising a control system operably coupled to the motor assembly, and wherein the motor assembly comprises an electric motor. 
     
     
         7 . The pump system of  claim 6 , wherein:
 the control system operable to sequentially switch between a first stroke at a first stroke speed of the piston and a second stroke at a second stroke speed of the piston;   the first adjustable chamber comprises a first minimum volume at a start of the first stroke and a first maximum volume at an end of the first stroke and the second adjustable chamber comprises a second minimum volume at a start of the second stroke and a second maximum volume at an end of the second stroke;   the first minimum volume is less than the second minimum volume;   the first maximum volume is less than the second maximum volume; and   the second stroke speed is greater than the first stroke speed.   
     
     
         8 . The pump system of  claim 1 , wherein the piston cylinder pump further comprises:
 a first valve fluidly coupled to and between the first adjustable chamber and a first feed line;   a second valve fluidly coupled to and between the first adjustable chamber and a first discharge line;   a third valve fluidly coupled to and between the second adjustable chamber and a second feed line; and   a fourth valve fluidly coupled to and between the second adjustable chamber and a second discharge line.   
     
     
         9 . The pump system of  claim 1 , further comprising a first port in the cylinder body and in fluid communication with the first adjustable chamber, a first feed line, and a first discharge line; and a second port in the cylinder body and in fluid communication with the second adjustable chamber, a second feed line, and a second discharge line. 
     
     
         10 . The pump system of  claim 9 , wherein a first pair of valves controls the fluid communication between the first port and the first feed line and the first discharge line, and wherein a second pair of valves controls the fluid communication between the second port and the second feed line and the second discharge line. 
     
     
         11 . The pump system of  claim 10 , wherein the first pair of valves comprises a first valve located between the first port and the first feed line and a second valve located between the first port and the first discharge line, and wherein the second pair of valves comprises a third valve located between the second port and the second fluid source, and a fourth valve located between the second port and the second fluid discharge. 
     
     
         12 . The pump system of  claim 1 , wherein the linear actuator comprises a screw actuator, a hydraulic actuator, a pneumatic actuator, or any combination thereof. 
     
     
         13 . The pump system of  claim 1 , wherein the linear actuator comprises a ball screw actuator. 
     
     
         14 . The pump system of  claim 1 , further comprising a position feedback sensor coupled to at least one of the piston cylinder pump, the linear actuator, and the motor assembly. 
     
     
         15 . The pump system of  claim 1 , wherein the motor assembly comprises a servomotor. 
     
     
         16 . A pump system, comprising:
 a piston cylinder pump comprising a piston located within a cavity of a cylinder body and dividing the cavity into a first adjustable chamber and a second adjustable chamber, wherein the piston comprises a first side opposite a second side and a rod coupled to the first side of the piston;   a linear actuator comprising a shaft coupled to the rod, wherein the linear actuator converts rotational motion to linear motion to move the rod linearly; and   an electric motor assembly coupled to the linear actuator and operable to drive the linear actuator;   wherein the piston is moveable linearly in a two-stroke cycle that comprises a first stroke away from the linear actuator and a second stroke toward the linear actuator, wherein the first stroke is slower than the second stroke.   
     
     
         17 . The pump system of  claim 16 , wherein:
 the first adjustable chamber has a first minimum volume at a start of the first stroke and a first maximum volume at an end of the first stroke;   the second adjustable chamber has a second minimum volume at a start of the second stroke and a second maximum volume at an end of the second stroke; and   the first maximum volume is less than the second maximum volume.   
     
     
         18 . The pump system of  claim 16 , wherein the piston cylinder pump further comprises:
 a first port defined in the cylinder body and in fluid communication with the first adjustable chamber;   a second port defined in the cylinder body and in fluid communication with the second adjustable chamber;   a third port defined in the cylinder body and in fluid communication with the first adjustable chamber;   a fourth port defined in the cylinder body and in fluid communication with the second adjustable chamber;   a first valve fluidly coupled to and between the first port and a first feed line;   a second valve fluidly coupled to and between the second port and a first discharge line;   a third valve fluidly coupled to and between the third port and a second feed line; and   a fourth valve fluidly coupled to and between the fourth port and a second discharge line.   
     
     
         19 . The pump system of  claim 18 , wherein each of the valves is a check valve. 
     
     
         20 . A method for pumping a fluid, comprising:
 sequentially switching between a first stroke at a first stroke speed and a second stroke at a second stroke speed of a piston located within a cylinder body of a piston cylinder pump, wherein the second stroke speed is greater than the first stroke speed, and wherein the piston cylinder pump comprises a first adjustable chamber and a second adjustable chamber separated from each other by the piston;   linearly moving the piston in a first direction to adjust from a first minimum volume of the first adjustable chamber at a start of the first stroke to a first maximum volume of the first adjustable chamber at an end of the first stroke;   linearly moving the piston in a second direction opposite of the first direction to adjust from a second minimum volume of the second adjustable chamber at a start of the second stroke to a second maximum volume of the second adjustable chamber at an end of the second stroke; and   discharging fluid from the first and second adjustable chambers at substantially the same flowrate.