| 摘要 |
PURPOSE:To obtain a pulley or the like excellent in surface smoothness and out of roundness without the necessity for performing afterwork, by forming a thin plastic layer to surfaces of a core material, made of material in high regidity and high strength, through the method of compression molding and other plastic molding. CONSTITUTION:In case of application to a pulley, this pulley A is prepared in such a manner that plastic, for instance, phenol resin, epoxy resin, etc., with the small linear expansion coefficient and high strength further with excellent chemical resistance, heat resistance and wear resistance, is integrally formed to the peripheral surface of a core material 2, amde from material in high rigidity and high strength like ceramics, metal, etc., by the method of compression molding, transfer molding, injection molding, etc. In this way, a high accurate pulley or cam, excellent in out of roundness, needless to say its surface smoothness, can be manufactured in a short molding time without the necessity for afterwork. |
