Variable stroke length electrically operated diaphragm pump

Abstract

A variable stroke length EOD pump system is provided that includes a diaphragm pump and an electromagnetic linear actuator that operates the diaphragm pump. The linear actuator includes two stator halves, and an armature. The armature is supported for linear motion along an axis of and between field poles of the stator halves. Each stator half may also include a drive coil partially surrounded by a magnetically permeable core.

What is claimed: 
     
         1 . An electrically operated diaphragm pump system comprising:
 a diaphragm pump;   an electromagnetic linear actuator that operates the diaphragm pump;   wherein the linear actuator includes:
 two stator halves, and 
 an armature; 
   wherein the armature is supported for linear motion along an axis of and between field poles of the stator halves; and   wherein each stator half includes a drive coil partially surrounded by a magnetically permeable core.   
     
     
         2 . The pump system of  claim 1 , wherein the armature and the two stator halves are shaped and positioned such that a space between their closest surfaces forms parallel planes perpendicular to the armature's direction of motion. 
     
     
         3 . The pump system of  claim 1 , wherein an axial force acting on the armature is coupled to the pump's diaphragms through springs. 
     
     
         4 . The pump system of  claim 1 , wherein the armature of the electromagnetic linear actuator is movable to a range of positions relative to the backer plate when the diaphragm backer plate displacement is about equal to armature displacement as the diaphragm pump is operating in low restriction, and less than the armature displacement when the diaphragm pump is operating in high restriction. 
     
     
         5 . An electrically operated diaphragm pump system comprising: 
       a diaphragm pump;
 an electromagnetic linear actuator that operates the diaphragm pump; 
 wherein the linear actuator includes:
 two stator halves, and 
 an armature; 
 
 wherein the two stator halves include drive coils and magnetic cores; 
 wherein the armature is located in a space located between the two stator halves; 
 wherein the armature is supported for linear motion along an axis of and between field poles of the stator halves; and 
 a drive rod movable with the armature to move a pump diaphragm backer plate.