High pressure water pump, has regulated secondary hydraulic oil circuit used for driving reciprocating piston within double-action hydraulic cylinder

摘要

The water pump has a reciprocating piston (2) displaced within the pump cylinder (1), e.g. a double-action hydraulic cylinder, with a regulated secondary hydraulic oil circuit (6) used for the piston drive, containing a 4/2-way valve (8) for controlling the movement direction of the piston. The latter has a H-shaped cross-section with an outer annular piston surfaces (21) and an inner cylindrical piston surfaces (22).