Fluid pump

Abstract

A pump including a first piston positioned within a first chamber having a first inlet and a first outlet. A second piston is positioned within a second chamber and is secured to the first piston. The diameter of the first piston is larger than the diameter of the second piston. The second chamber has a second inlet and a second outlet. The second inlet is in communication with the first outlet of the first chamber. A drive system reciprocates the first and second pistons in unison within the first and second chambers such that fluid is pumped into the first chamber, from the first chamber to the second chamber, and then expelled from the second chamber.

1 . A pump comprising: 
 a housing having a first chamber and a second chamber, the first chamber having a first inlet and a first outlet, the second chamber having a second inlet and a second outlet, the second inlet being in communication with the first outlet of the first chamber;    a first piston positioned within the first chamber;    a second piston positioned within the second chamber and secured to the first piston, the first and second pistons each having a diameter, the diameter of the first piston being larger than the diameter of the second piston; and    a drive system for reciprocating the first and second pistons in unison within the first and second chambers such that when the first piston is moving in an expansion stroke, fluid can be drawn into the first chamber through the first inlet, and at the same time, the second piston is moving in a compression stroke where fluid can be expelled from the second chamber through the second outlet, and when the first piston is moving in a compression stroke, the second piston is moving in an expansion stroke where fluid can be expelled from the first chamber through the first outlet and into the second chamber through the second inlet.    
   
   
       2 . The pump of  claim 1  further comprising a connecting member for securing the first and second pistons together in a spaced apart manner along a common axis, and extending between the first and second chambers.  
   
   
       3 . The pump of  claim 2  in which the connecting member includes a threaded screw, the drive system including a rotatable nut engaged with the threaded screw and a reversible motor for alternately rotating the nut in opposite directions, to cause reciprocating linear translation of the connecting member and pistons.  
   
   
       4 . The pump of  claim 3  in which the nut is a ball screw nut.  
   
   
       5 . The pump of  claim 1  further comprising a check valve system for preventing back flow through the pump.  
   
   
       6 . The pump of  claim 5  in which the check valve system comprises a first check valve for preventing fluid from exiting the first chamber through the first inlet.  
   
   
       7 . The pump of  claim 6  in which the check valve system further comprises a second check valve for preventing fluid from exiting the second chamber through the second inlet.  
   
   
       8 . The pump of  claim 7  in which the check valve system further comprises a third check valve for preventing fluid from entering the second chamber through the second outlet.  
   
   
       9 . The pump of  claim 1  further comprising a piston position sensing system.  
   
   
       10 . The pump of  claim 1  further comprising a first pressure sensor for sensing pressure in the first chamber.  
   
   
       11 . The pump of  claim 10  further comprising a second pressure sensor for sensing pressure of fluid expelled from the second chamber.  
   
   
       12 . The pump of  claim 1  in which the diameters of the first and second pistons have a difference in size of about a 3.5 to 1 ratio.  
   
   
       13 . The pump of  claim 12  in which the first and second pistons have a stroke of about 6 inches.  
   
   
       14 . The pump of  claim 13  in which the pump is capable of pumping about 0.5 in. 3  of gas at about 2200 psi per cycle.  
   
   
       15 . A pump comprising: 
 a housing having a first chamber and a second chamber, the first chamber having a first inlet and a first outlet, the second chamber having a second inlet and a second outlet, the second inlet being in communication with the first outlet of the first chamber;    a first piston positioned within the first chamber;    a second piston positioned within the second chamber and secured to the first piston, the first and second pistons each having a diameter, the diameter of the first piston being larger than the diameter of the second piston;    a connecting member for securing the first and second pistons together in a spaced apart manner along a common axis, and extending between the first and second chambers, the connecting member including a threaded screw;    a drive system for reciprocating the first and second pistons in unison within the first and second chambers such that when the first piston is moving in an expansion stroke, fluid can be drawn into the first chamber through the first inlet, and at the same time, the second piston is moving in a compression stroke where fluid can be expelled from the second chamber through the second outlet, and when the first piston is moving in a compression stroke, the second piston is moving in an expansion stroke where fluid can be expelled from the first chamber through the first outlet and into the second chamber through the second inlet, the drive system including a rotatable ball screw nut engaged with the threaded screw and a reversible motor for alternately rotating the nut in opposite directions to cause reciprocating linear translation of the connecting member and pistons; and    a check valve system for preventing back flow through the pump.    
   
   
       16 . The pump of  claim 15  in which the check valve system comprises a first check valve for preventing fluid from exiting the first chamber through the first inlet.  
   
   
       17 . The pump of  claim 16  in which the check valve system further comprises a second check valve for preventing fluid from exiting the second chamber through the second inlet.  
   
   
       18 . The pump of  claim 17  in which the check valve system further comprises a third check valve for preventing fluid from entering the second chamber through the second outlet.  
   
   
       19 . The pump of  claim 15  further comprising a piston position sensing system.  
   
   
       20 . The pump of  claim 15  further comprising a first pressure sensor for sensing pressure in the first chamber.  
   
   
       21 . The pump of  claim 20  further comprising a second pressure sensor for sensing pressure of fluid expelled from the second chamber.  
   
   
       22 . The pump of  claim 15  in which the diameters of the first and second pistons have a difference in size of about a 3.5 to 1 ratio.  
   
   
       23 . The pump of  claim 22  in which the first and second pistons have a stroke of about 6 inches.  
   
   
       24 . The pump of  claim 23  in which the pump is capable of pumping about 0.5 in. 3  of gas at about 2200 psi per cycle.  
   
   
       25 . A method of pumping fluid comprising: 
 positioning a first piston within a first chamber in a housing, the first chamber having a first inlet and a first outlet;    positioning a second piston within a second chamber in the housing, the first and second pistons being secured to each other and each having a diameter, the diameter of the first piston being larger than the diameter of the second piston, the second chamber having a second inlet and a second outlet, the second inlet being in communication with the first outlet of the first chamber; and    reciprocating the first and second pistons in unison within the first and second chambers with a drive system such that when the first piston is moving in an expansion stroke, fluid is drawn into the first chamber through the first inlet, and at the same time, the second piston is moving in a compression stroke where fluid is expelled from the second chamber through the second outlet, and when the first piston is moving in a compression stroke, the second piston is moving in an expansion stroke where fluid is expelled from the first chamber through the first outlet and into the second chamber through the second inlet.    
   
   
       26 . The method of  claim 25  further comprising securing the first and second pistons together in a spaced apart manner along a common axis with a connecting member extending between the first and second chambers.  
   
   
       27 . The method of  claim 26  in which the connecting member includes a threaded screw, the drive system including a rotatable nut engaged with the threaded screw, the method further comprising alternately rotating the nut in opposite directions with a reversible motor to cause reciprocating linear translation of the connecting member and pistons.  
   
   
       28 . The method of  claim 27  further comprising rotating a ball screw nut.  
   
   
       29 . The method of  claim 25  further comprising preventing back flow through the pump with a check valve system.  
   
   
       30 . The method of  claim 29  further comprising preventing fluid from exiting the first chamber through the first inlet with a first check valve of the check valve system.  
   
   
       31 . The method of  claim 30  further comprising preventing fluid from exiting the second chamber through the second inlet with a second check valve of the check valve system.  
   
   
       32 . The method of  claim 31  further comprising preventing fluid from entering the second chamber through the second outlet with a third check valve of the check valve system.  
   
   
       33 . The method of  claim 25  further comprising sensing piston position with a piston position sensing system.  
   
   
       34 . The method of  claim 25  further comprising sensing pressure in the first chamber with a first pressure sensor.  
   
   
       35 . The method of  claim 34  further comprising sensing pressure of fluid expelled from the second chamber with a second pressure sensor.  
   
   
       36 . The method of  claim 25  further comprising forming the diameters of the first and second pistons to have a difference in size of about a 3.5 to 1 ratio.  
   
   
       37 . The method of  claim 36  further comprising providing the first and second pistons with a stroke of about 6 inches.  
   
   
       38 . The method of  claim 37  further comprising pumping about 0.5 in. 3  of gas at about 2200 psi per cycle.  
   
   
       39 . A method of pumping fluid comprising: 
 positioning a first piston within a first chamber in a housing, the first chamber having a first inlet and a first outlet;    positioning a second piston within a second chamber in the housing, the first and second pistons being secured to each other and each having a diameter, the diameter of the first piston being larger than the diameter of the second piston, the second chamber having a second inlet and a second outlet, the second inlet being in communication with the first outlet of the first chamber;    securing the first and second pistons together in a spaced apart manner along a common axis with a connecting member extending between the first and second chambers, the connecting member including a threaded screw;    reciprocating the first and second pistons in unison within the first and second chambers with a drive system such that when the first piston is moving in an expansion stroke, fluid is drawn into the first chamber through the first inlet, and at the same time, the second piston is moving in a compression stroke where fluid is expelled from the second chamber through the second outlet, and when the first piston is moving in a compression stroke, the second piston is moving in an expansion stroke where fluid is expelled from the first chamber through the first outlet and into the second chamber through the second inlet, the drive system including a rotatable ball screw nut engaged with the threaded screw and a reversible motor for alternately rotating the nut in opposite directions to cause reciprocating linear translation of the connecting member and pistons; and    preventing back flow through the pump with a check valve system    
   
   
       40 . The method of  claim 39  further comprising preventing fluid from exiting the first chamber through the first inlet with a first check valve of the check valve system.  
   
   
       41 . The method of  claim 40  further comprising preventing fluid from exiting the second chamber through the second inlet with a second check valve of the check valve system.  
   
   
       42 . The method of  claim 41  further comprising preventing fluid from entering the second chamber through the second outlet with a third check valve of the check valve system.  
   
   
       43 . The method of  claim 39  further comprising sensing piston position with a piston position sensing system.  
   
   
       44 . The method of  claim 39  further comprising sensing pressure in the first chamber with a first pressure sensor.  
   
   
       45 . The method of  claim 44  further comprising sensing pressure of fluid expelled from the second chamber with a second pressure sensor.  
   
   
       46 . The method of  claim 39  further comprising forming the diameters of the first and second pistons to have a difference in size of about a 3.5 to 1 ratio.  
   
   
       47 . The method of  claim 46  further comprising providing the first and second pistons with a stroke of about 6 inches.  
   
   
       48 . The method of  claim 47  further comprising pumping about 0.5 in. 3  of gas at about 2200 psi per cycle.