Abstract: A reciprocating fluid pump includes a drive section and a pump section. The drive section has a pair of coils which may be energized to cause displacement of a reciprocating assembly. Each coil is a reluctance gap arrangement in which a magnetic circuit is interrupted by a gap towards which an armature of the reciprocating assembly is drawn when energizing current is applied to the coil. The reciprocating assembly includes an element which is extended into and retracted from a pump chamber during its reciprocating motion, causing fluid to be drawn into and expelled from the pump chamber. The pump is particularly well suited for use in cyclic pumping applications, such as internal combustion engine fuel injection. Cycle times in such applications may be reduced by appropriate control of the current waveforms applied to the coils.

Abstract: A downhole pumping system includes a downhole pump that is coupled to a downhole motor. The downhole motor includes a motor protector that utilizes one or more retractable and extensible pistons, instead of an elastomeric bag, to accommodate motor oil contraction and expansion. The motor protector may also include one or more contamination containment sections for processing contaminants in downhole fluid to reduce contamination of the motor oil.