Method for producing polymer rotors

摘要

The invention relates to a method of manufacturing a rotor (12) for a helical screw machine that includes a metal shaft (2) and helical lobes (9) mutually separated by intermediate grooves (13), comprising the steps of providing the shaft (2) with a blind axially extending passageway (10); connecting the passageway (10) with the barrel surface of the shaft (2) by means of at least one channel (11) extending outwardly from the shaft; inserting the rotor shaft (2) in a mold (1) that includes two mutually spaced end-walls (4, 5) which have respective rotor shaft receiving openings (6 and 7), said openings (4, 5) embracing the rotor shaft (2, 19) at least in a generally sealing fashion; heating the mold (1) and the shaft (2) to the curing temperature of the polymer; delivering polymer-forming materials to the mold (1); maintaining the barrel wall (3) of the mold (1) at said curing temperature until the polymer has cured; and removing the rotor from the mold (1). The method is characterized by the further steps of disposing the outwardly extending channel (11) on the shaft (2) such that said channel will be located generally in the middle of the mold (1) when the shaft (2) is inserted therein; and pressing the polymer into the axially extending passageway (10) at an overpressure of at least 1 bar.