ELEKTROHYDRAULISCHES GERAET

摘要

An electrohydraulic machine for generating a force on a vertically movable piston rod (5) linked to the piston (4) of a cylinder (3) has a first centrifugal pump (17, 18) arranged in the part of the cylinder (3) opposite to the piston rod (5) and linked by a shaft (15) to an electric motor (2), as well as a housing for the cylinder and centrifugal pump that delimits a reservoir for the working fluid. A second centrifugal pump (18, 19) is arranged underneath the first centrifugal pump (17, 18) and both centrifugal pumps (17, 19; 18, 19) are in communication with the reservoir (14) through a duct (21, 22). The cylinder chamber (6) is closed above the piston (4) in relation to the reservoir (14) and is linked to the second centrifugal pump (18, 19) by means of a pressure line (24). When the electric motor (2) turns in a predetermined direction of rotation, the first centrifugal pump (17, 19) is driven by the shaft (15) and when it turns in the opposite direction of rotation the second centrifugal pump (18, 19) is driven by the shaft (15), whereas, in each case, the other centrifugal pump runs freely, so that the piston (4) may be moved both upwards and downwards.