Pump Piston Device

Abstract

A pump piston device is for reciprocating movement in a pump cylinder. Between the pump piston and the pump cylinder, an annular space is formed which is defined by a first seal and a second seal, the annular space being pressurized, and the first seal and the second seal being in a common piece of material which constitutes the pump piston.

1 . A pump piston device for reciprocating movement in a pump cylinder in which there is formed, between the pump piston and the pump cylinder, an annular space which is defined by a first seal and a second seal, the annular space being pressurized, and the first seal and the second seal being in a common piece of material which constitutes the pump piston, wherein a compensation piston is movable in a compensation cylinder in the pump piston, the compensation piston communicating, by its first end portion, with the pressure side of the pump piston, and, at its second end portion, with the annular space via a piston channel. 
     
     
         2 . The device in accordance with  claim 1 , wherein the annular space is supplied with pressure fluid via a check valve and a cylinder channel.