SCREW ROTOR

摘要

PURPOSE:To exhibit a large resistance against a force acting in a swing direction by engraving grooves or forming protrusions, on a metallic shaft, for including lead angles opposing to the lead angle possessed by a rotor. CONSTITUTION:A male screw rotor 1 comprises a metallic shaft 2 and a synthetic resin made rotor 3 for covering the shaft 2. The synthetic resin made rotor 3 is formed on the metallic shaft 2 by injection molding and equipped with 4 lines of screw on its periphery. Four lines of grooves 4 having lead angles opposite to the direction of the lead angles possessed by the rotor 3 engraved along the total length of the portion to be covered by the rotor 3 are engraved on the surface of the metallic shaft 2. When the synthetic resin made rotor 3 is under the process of injection molding, the synthetic resin enters the grooves 4 engraved on the surface of the metallic shaft 2 and hardens there.