Abstract: A pump assembly. The pump assembly may comprise a motor portion for driving a fluid pumping portion via a piston. The motor portion may comprise: a spool and a spool housing assembly having a spool chamber. The spool may be disposed within the spool chamber. The spool may comprise an upper portion and a lower portion, wherein the diameter of the lower portion is larger than the diameter of the upper portion. The spool may also comprise: (1) two support groove portions for cradling two slide valves and (2) two spool bores, which are in fluid communication with the two slide valves. The piston of the pump assembly may comprise a valve stem having a valve stem bore and valve stem openings. The valve stem openings may be funnel-shaped or may inwardly slope into the valve stem bore to prevent or minimize cutting or shredding of a blown seal.

Abstract: A zero emission reciprocating drive pump. The reciprocating drive pump may comprise: a spool and housing assembly. The housing assembly may comprise a flange, spool housing, first chamber, second chamber, and first seal. The flange may attached to a proximal end of the spool housing. The first chamber may be within the flange. The second chamber may be within the spool housing. The spool may be substantially disposed in and reciprocally movable in the second chamber. A proximal end portion of the spool may move reciprocally into and out of the first chamber. The first seal may be positioned substantially adjacent to the first chamber and the second chamber and may contact the proximal end portion of the spool. The flange may comprise a lip that extends substantially along a width of a distal end of the first seal, such that the first seal does not pop out of place.

Abstract: A reciprocating drive mechanism. The reciprocating drive mechanism may comprise: a spool assembly and a spool housing. The spool assembly may be reciprocally movable within a spool chamber of the spool housing. The spool housing may comprise a first seal, a second seal, and a third seal. When the spool assembly is within the spool chamber, the first seal, the second seal, and the third seal may divide the spool chamber into a distal chamber, an intermediate chamber, a supply chamber, and a proximal chamber, respectively. The spool assembly may comprise a first spool vent that is in fluid communication with the distal chamber. The spool housing may comprise a first housing vent that is in fluid communication with the intermediate chamber. The first spool vent may be in fluid communication with the first housing vent when an outlet of the first spool vent is aligned within the intermediate chamber.