Abstract: A hydraulic screw machine having a housing employing a screw assembly with a drive screw and cooperating idler screws. The drive screw is sealably connected to a shaft extending beyond the housing on the high pressure side and has associated therewith a balance piston for acting on the screw drive. The drive screw is journalled to the shaft via bearings in the form of a self-adjusting plate surrounding the shaft. The plate is disposed between abutment surfaces connected to the housing for limiting its axial movement. A leakage channel between the piston and the housing is connected to the high pressure side of the machine and is determined by the balance piston.

Abstract: A screw pump includes a screw unit having a drive screw and two impeller screws arranged symmetrically around the drive screw. The screws are enclosed in a housing having mutually intersecting passages for accommodating the screws, and the unit is constructed so that the screws seal against each other and against the housing to form chambers in which liquid is carried from the suction side to the pressure side during rotation of the screws. On the pressure side in the passage accommodating one of the impeller screws there is formed a recess which extends from the pressure side and the length of which is such that each chamber is opened at separate time intervals with respect to the two impeller screws instead of simultaneously.