A drive system for a pump includes a housing and a fluid displacer and a reciprocator configured to mechanically displace the fluid displacer through respective suction strokes. The housing and fluid displacer define an internal pressure chamber configured to be filled with a working fluid having a charge pressure. The internal pressure chamber is configured such that the working fluid exerts the charge pressure on the fluid displacer during both the suction stroke and a pressure stroke of the fluid displacer.

A thick matter pump includes a hydraulically-driven two-cylinder piston-pump configured to generate a thick matter delivery pressure. The thick matter pump also includes a hydraulic pump configured to apply hydraulic fluid to the two-cylinder piston-pump via a drive line. The hydraulic pump includes a pressure regulator that is adjustable to a target value of pressure of the hydraulic fluid for limiting the thick matter delivery pressure, and the thick matter delivery pressure is adjustably limited. The pressure of the hydraulic fluid is limited in the drive line, via an adjustable pressure-limiting valve, to an adjustable maximum pressure. The target pressure of the pressure regulator and the maximum pressure of the hydraulic fluid are adjustable through a joint adjusting element.

A hydraulic piston pump includes a reciprocal piston disposed in a blind housing bore of a piston housing to generate a pumping action. To accommodate the piston, a piston cartridge is installed in each of the housing bores. The piston cartridge includes a piston sleeve having an inner sleeve periphery, a first outer sleeve periphery, and a second outer sleeve periphery. The inner sleeve periphery is configured to establish sliding contact with the piston. The first outer sleeve periphery has a first outer sleeve diameter that is larger than a second outer sleeve diameter of the second outer sleeve periphery. To seal against the blind housing bore, a liner cap having a cylindrical liner wall and an axial liner cover is disposed over the first outer sleeve periphery. The axial liner cover abuts a housing bore ceiling of the blind housing bore and can receive hydraulic fluid there through.

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.

The invention provides an apparatus for compressing a first fluid. The apparatus comprises a compressor piston comprising a piston cylinder and a piston assembly slidably mounted therein. The piston assembly comprises first and second spaced apart piston members defining a space therebetween. The space is configured to contain a second fluid used to cause compression of the first fluid. The piston assembly further comprises means for feeding second fluid to the space between the first and second piston members.

A drive system for a pump includes a housing defining an internal pressure chamber, a working fluid disposed within and charging the internal pressure chamber, and a reciprocating member disposed within the internal pressure chamber. The reciprocating member has a pull chamber. A pull is secured within the pull chamber, and a fluid displacement member is coupled to the pull.

A method of displacing fluid includes pulling a pump displacement member through a suction stroke with a pull, the pull configured to transmit only tensile forces to the fluid displacement member. A working fluid disposed in an internal pressure chamber drive the fluid displacement member through a pumping stroke. The pull is prevented from transmitting any compressive forces to the fluid displacement member, such that the pull does not drive the fluid displacement member through the pumping stroke.

A cryogenic fluid pump includes a plurality of pumping elements, each of the plurality of pumping elements having an actuator portion that is associated with and configured to selectively activate one end of a pushrod in response to a command by an electronic controller, an activation portion associated with an opposite end of the pushrod, and a pumping portion associated with the activation portion. For each of the plurality of pumping elements, the pumping portion is activated for pumping a fluid by the activation portion, which activation portion is activated by the actuator portion. The electronic controller is configured to selectively activate each of the plurality of pumping elements such that a flow of fluid from the cryogenic fluid pump results from continuous activations of the plurality of pumping elements at selected dwell times between activations of successive pumping elements.

A cryogenic fluid pump includes an outlet tube extending along the pump centerline, the outlet tube having an outlet passage that is fluidly in communication with the combined outlet and with a pump outlet opening, and a shroud that extends concentrically along the outlet tube and has an inner diameter that is larger than an outer diameter of the outlet tube such that a gap is formed in a radial direction between an inner surface of the shroud and an outer surface of the outlet tube, the gap extending along at least a portion of the outlet tube.

A hydraulic piston pump includes a piston disposed in a blind housing bore of a piston housing and that reciprocates to generate a pumping action. To accommodate the piston, a piston cartridge is installed in each of the housing bores. The piston cartridge includes a piston sleeve having an inner sleeve periphery, a first outer sleeve periphery, and a second outer sleeve periphery. The inner sleeve periphery is configured to establish sliding contact with the piston. The first outer sleeve periphery has a first outer sleeve diameter that is larger than a second outer sleeve diameter associated with the second outer sleeve periphery. To seal against the blind housing bore, a liner cap having a cylindrical liner wall and an axial liner cover is disposed over the first outer sleeve periphery. The axial liner cover abuts a housing bore ceiling of the blind housing bore and can receive hydraulic fluid there through.