Abstract: A pump system for delivering cryogenic liquids is proposed that is suitable, for example, for refueling motor vehicles with H2. It consists of a container for receiving the cryogenic liquid, in which at least one pump is arranged that is designed as a reciprocating pump with connecting rod actuation and spring recover. Pump cylinder (10) of the reciprocating pump is divided by means of plunger (24, 37) into two chambers (a and b) that are arranged on the pressure side or the induction side. By exerting tensile forces on connecting rod (29), in the pressure stroke the cryogenic liquid that is located in the container is initially trapped in chamber (b). When connecting rod (29) is returned to its starting position by return spring (23), the liquid that is trapped in chamber (b) is then hurled without pressure into chamber (a). In the subsequent pressure stroke, the liquid is finally released via a gap (d) to a pressure housing and from there to the consumer by exerting tensile forces on connecting rod (29).

Abstract: A piston pump for conveying a fluid includes a cylinder which is not flanged to the pump casing, but rather is inserted in the pump casing and is retained in the longitudinal direction by a pretensioned spring. A seal is arranged between the cylinder jacket and the pump casing in order to seal the pressure side with respect to the suction side of the piston pump. An extremely compact piston pump results therefrom, suitable, in particular, for use in the low-temperature range due to very low cold losses.

Abstract: A piston pump for conveying cryogenic fluids, especially liquid hydrogen, permits reliable transport of relatively large amounts of the fluid at high conveying pressures even with horizontal operation of the pump. The actual pump is inserted in an inner casing pipe (3, 25) of a vacuum housing. The pump is connected by a thread at one end of the housing and sealed against the atmosphere by an O-ring. The cylinder of the piston pump is sealed with respect to the inner casing pipe on the high-pressure side as well as on the low-pressure side by means of synthetic resin gaskets.

Abstract: A piston pump having an intake valve whose valve member is approached by the pump piston. The piston magnetically attracts the valve member during the intake stroke to overcome the force of the spring biasing the valve member into its closed position.