Screw rotor machine having means for axially biasing at least one of the rotors

摘要

A helical screw rotor machine is provided which has at least one trunnion having an axial thrust surface located in a chamber filled with pressure medium and actuated axially by the pressure medium. A casing is closely fitted around the trunnion. The casing has an outer end which is connected to a bottom wall that includes a hole in its center, and the casing is rotatably and slidably mounted on the trunnion and is movable between a first axial position in which the bottom wall is spaced from an end wall of the chamber and a second axial position in which the bottom wall is in abutment with said end wall. A supply channel is connected to an opening in the end wall of the chamber opposite the hole in the bottom wall of the casing for controlled delivery of the pressure medium into the casing.