A method of actuating a double-action pump assembly with a reciprocating plunger includes signaling the reciprocating plunger to stop for a changeover period; while the pump is stopping, signaling the first inlet and outlet valves to close; while the first inlet and outlet valves are closing, signaling the second inlet and outlet valves to open, such that the second inlet and outlet valves begin to mechanically open at least a dwell period after the first inlet and outlet valves have entirely closed; and signaling the reciprocating plunger to begin moving while the second inlet and outlet valves are closing.

A method of actuating a double-action pump assembly with a reciprocating plunger includes signaling the reciprocating plunger to stop for a changeover period; while the pump is stopping, signaling the first inlet and outlet valves to close; while the first inlet and outlet valves are closing, signaling the second inlet and outlet valves to open, such that the second inlet and outlet valves begin to mechanically open at least a dwell period after the first inlet and outlet valves have entirely closed; and signaling the reciprocating plunger to begin moving while the second inlet and outlet valves are closing.

A piston pump, in particular for a motor vehicle, includes a piston that is movably mounted in a housing. The piston pump further includes a linear actuator for moving the piston in a first direction. The piston pump further includes a return spring for moving the piston in a second direction. The end face of a first end of the piston delimits a first pressure chamber that is associated with a first hydraulic circuit. The end face of a second end of the piston delimits a second pressure chamber.

A piston pump, in particular for a motor vehicle, includes a piston that is movably mounted in a housing. The piston pump further includes a linear actuator for moving the piston in a first direction. The piston pump further includes a return spring for moving the piston in a second direction. The end face of a first end of the piston delimits a first pressure chamber that is associated with a first hydraulic circuit. The end face of a second end of the piston delimits a second pressure chamber.

A pump comprises a drive mechanism, a tube coupled to the drive mechanism, a filament coupled to the tube and extendable into the tube by the drive mechanism and at least one check valve coupled to the tube. As the filament is forced by the drive mechanism into the tube, fluid contained in the tube is forced by the filament through the at least one check valve and out of the tube.

The invention relates to the special configuration of a compression device of a refrigeration system and to its actuation method. The device consists of a pair of dual-action cylinders (8-9) connected together by means of the movable rod (11) thereof, such that the first cylinder (8) acts as an element for compressing coolant fluid, for which purpose the rod is moved through the second cylinder (9), being fed by a pressurised fluid which, by means of a series of branches and valves controlled using limit switches of the rod (11), allow the flow of coolant fluid in the first cylinder and the flow of pressurised fluid of the second cylinder at the outlet of both devices to be constant. Thus, a completely autonomous device that does not need electricity or any type of fuel is obtained.

The invention relates to the special configuration of a compression device of a refrigeration system and to its actuation method. The device consists of a pair of dual-action cylinders (8-9) connected together by means of the movable rod (11) thereof, such that the first cylinder (8) acts as an element for compressing coolant fluid, for which purpose the rod is moved through the second cylinder (9), being fed by a pressurised fluid which, by means of a series of branches and valves controlled using limit switches of the rod (11), allow the flow of coolant fluid in the first cylinder and the flow of pressurised fluid of the second cylinder at the outlet of both devices to be constant. Thus, a completely autonomous device that does not need electricity or any type of fuel is obtained.

A vehicle-mounted electric oil-free air compressor, including a motor, a box body, a piston, and a flywheel shaft. The motor is fixed on the box body, a cylinder cover is at the top of the box body, a main shaft of the motor includes a coupling driving end, the flywheel shaft is driven by an elastic body to rotate. The piston includes a primary intake valve piece and a primary exhaust valve piece, the box body is provided with a secondary cavity, a secondary exhaust valve piece is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece is also a secondary intake valve piece of the compressor, increasing the exhaust pressure. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.

A reciprocating piston pump assembly comprises a cylinder housing with two internal chambers separated by a piston. The piston is coupled with a pushrod that reciprocates back and forth between two positions. The piston's position is tracked to measure the volume of fluid passing through the pump assembly. The pump assembly has two inlets, two outlets, two inlet passages, and two outlet passages. A first valve is positioned on the pushrod at a junction between the first inlet passage and first outlet passage. A second valve is positioned on the pushrod at a junction between the second inlet passage and second outlet passage. The pushrod can be positioned in a neutral position to simultaneously close both valves.

A method for a system having a plurality of primary fluid sources and a fluid output with a common pump includes halting pumping of a first fluid, isolating the common pump from the fluid output and the primary fluid sources, connecting an inlet of the common pump to a solvent source and a compressed air source, and an outlet of the common pump to a waste fluid dump, filling the common pump with a first purge volume of solvent, cycling the common pump in a flush mode, operating the common pump in a timed flow mode, and connecting an inlet of the common pump to a second primary fluid source, and an outlet of the common pump to the output line, and starting pumping of a second fluid from the second primary fluid source through the output line.