ROTOR WITH PULLEY OF ELECTROMAGNETIC CLUTCH AND MANUFACTURE OF THE SAME

PURPOSE:To simplify the manufacturing and reduce the weight by making a coil case unit and a pulley unit in an integral structure comprising a plastically deformed mold of a single material. CONSTITUTION:After a coil case material 18 consisting of a circular body with a U-shaped cross section is formed of a hollow disk material 10, a rotor is manufactured via a first intermediate material 19, a second intermediate material 20 and a third intermediate material 21, so that when the rotor is worked by cool indentation during a third process for obtaining the intermediate material 20 and a fourth process for obtaining the intermediate material 21, indentation amounts in both directions are relatively adjusted to permit an attaching position of a pulley unit 12 to a coil case unit 11 and a relative position of the pulley unit 12 to the coil case unit 11 to be varied as desired. This manufacturing method comprises plastic deformation molding in any process and it is possible to manufacture without a process for joining plural members such as a welding process, so that high strength can be obtained and also an amount of materials to be used can be reduced.