Drive system for a positive displacement pump

Abstract

A drive system for a pump includes a housing, first and second fluid displacement members, a solenoid disposed within the housing, and a reciprocating member configured to be driven by the solenoid. The reciprocating member is connected to the first and second fluid displacement members and is configured to mechanically displace the first and second fluid displacement members.

1 . A drive system for a displacement pump, the drive system comprising:
 a first housing;   a first fluid displacement member disposed at a first end of the first housing;   a second fluid displacement member disposed at a second end of the first housing;   a solenoid disposed within the first housing; and   a reciprocating member disposed within the solenoid and configured to be driven by the solenoid;   wherein the reciprocating member is connected to the first fluid displacement member and the second fluid displacement member to mechanically displace the first fluid displacement member and the second fluid displacement member.   
     
     
         2 . The drive system of  claim 1 , wherein the first fluid displacement member comprises a first diaphragm and the second fluid displacement member comprises a second diaphragm, wherein the first diaphragm, the second diaphragm, the reciprocating member, and the solenoid are disposed coaxially on a pump axis, and wherein the reciprocating member is configured to reciprocate on the pump axis. 
     
     
         3 . The drive system of  claim 2 , further comprising:
 a first fluid cover abutting the first end of the first housing, wherein a circumferential edge of the first diaphragm is retained between the first fluid cover and the first housing.   
     
     
         4 . The drive system of  claim 2 , wherein:
 the first diaphragm includes a first attachment screw;   the reciprocating member is connected to the first attachment screw.   
     
     
         5 . The drive system of  claim 1 , wherein the reciprocating member is connected to the first fluid displacement member by a first intermediate member and connected to the second fluid displacement member by a second intermediate member. 
     
     
         6 . The drive system of  claim 1 , wherein the solenoid and the reciprocating member are disposed between the first fluid displacement member and the second fluid displacement member. 
     
     
         7 . The drive system of  claim 1 , wherein the reciprocating member is configured to oscillate along a pump axis to drive the first fluid displacement member and the second fluid displacement member through respective suction strokes. 
     
     
         8 . The drive system of  claim 7 , wherein the reciprocating member comprises:
 an armature configured to be driven along a pump axis by an electrical field generated by the solenoid.   
     
     
         9 . The drive system of  claim 8 , wherein the reciprocating member further comprises:
 a first end member extending from the armature, wherein the first end member is connected to the first fluid displacement member; and   a second end member extending from the armature, wherein the second end member is connected to the second fluid displacement member.   
     
     
         10 . The drive system of  claim 7 , further comprising:
 a second housing disposed within the first housing;   wherein the solenoid is disposed within the second housing; and   wherein the first housing and the second housing are disposed coaxially on the pump axis.   
     
     
         11 . The drive system of  claim 10 , wherein the first housing defines an internal chamber within which the second hosing is disposed. 
     
     
         12 . The drive system of  claim 11 , further comprising:
 a first fluid cover abutting the first end of the first housing, wherein a circumferential edge of the first fluid displacement member is retained between the first fluid cover and the first housing;   a second fluid cover abutting the second end of the first housing, wherein a circumferential edge of the second fluid displacement member is retained between the second fluid cover and the first housing;   wherein the first fluid displacement member and the first fluid cover define a first fluid cavity therebetween;   wherein the second fluid displacement member and the second fluid cover define a second fluid cavity therebetween; and   wherein the first fluid displacement member sealingly separates the first fluid cavity from the internal chamber and the second fluid displacement member sealingly separates the second fluid cavity from the internal chamber.   
     
     
         13 . The drive system of  claim 7 , wherein the solenoid is configured to drive the reciprocating member in a first direction towards the first fluid displacement member and in a second direction towards the second fluid displacement member. 
     
     
         14 . The drive system of  claim 13 , wherein the first direction is away from the second fluid displacement member. 
     
     
         15 . A displacement pump comprising:
 a first cover having a first fluid inlet and a first fluid outlet;   a second cover having a second fluid inlet and a second fluid outlet;   a drive system comprising:
 a first housing disposed between the first cover and the second cover; 
 a solenoid disposed within the first housing; and 
 a reciprocating member disposed within the solenoid and configured to be driven by the solenoid along a pump axis; 
   a first diaphragm disposed between the first cover and the first housing, wherein the first diaphragm is configured to pump fluid through a first cavity defined between the first diaphragm and the first cover; and   a second diaphragm disposed between the second cover and the first housing, wherein the second diaphragm is configured to pump fluid through a second cavity defined between the second diaphragm and the second cover;   wherein the reciprocating member is configured to mechanically displace the first diaphragm and the second diaphragm.   
     
     
         16 . The displacement pump of  claim 15 , wherein the reciprocating member comprises:
 an armature disposed within the solenoid and configured to be driven along the pump axis by an electrical field generated by the solenoid;   a first connector extending from a first end of the armature and attached to the first diaphragm; and   a second connector extending from a second end of the armature and attached to the second diaphragm.   
     
     
         17 . The displacement pump of  claim 16 , further comprising:
 a first attachment screw extending from the first diaphragm, wherein the first attachment screw is attached to the first connector; and   a second attachment screw extending from the second diaphragm, wherein the second attachment screw is attached to the second connector.   
     
     
         18 . The displacement pump of  claim 15 , wherein the solenoid, the reciprocating member, the first diaphragm, and the second diaphragm are disposed coaxially on the pump axis. 
     
     
         19 . The displacement pump of  claim 15 , wherein:
 the solenoid and the reciprocating member are disposed between the first diaphragm and the second diaphragm;   the solenoid is configured to drive the reciprocating member in a first direction towards the first diaphragm and in a second direction towards the second diaphragm;   the reciprocating member is configured to pull the first diaphragm in the second direction to cause the first diaphragm to enter a suction stoke; and   the reciprocating member is configured to pull the second diaphragm in the first direction to cause the second diaphragm to enter a suction stroke.   
     
     
         20 . A method comprising:
 driving, with a solenoid, an armature along a pump axis in a first direction;   pulling, with the armature, a first fluid displacement member in the first direction such that first fluid displacement member enters a suction stroke, wherein the first fluid displacement member pulls fluid into a first fluid chamber defined between the first fluid displacement member and a first fluid cover during the suction stroke;   driving, with the solenoid, the armature along the pump axis in a second direction opposite the first direction;   pulling, with the armature, a second fluid displacement member in the second direction such that second fluid displacement member enters a suction stroke, wherein the second fluid displacement member pulls fluid into a second fluid chamber defined between the second fluid displacement member and a second fluid cover during the suction stroke;   wherein the first fluid displacement member is sealingly disposed between a first housing and the first fluid cover;   wherein the second fluid displacement member is sealingly disposed between the first housing and the second fluid cover.