Method for producing a magnetic rotatable member for an electromagnetic

Abstract

A method for producing a magnetic rotatable member as a part of a pulley in an electromagnetic clutch is proposed. In order to reduce the producing time and the wasted material amount, the rotatable member is formed by press-drawing a magnetic circular plate to form an annular body consisted of an outer annular cylindrical portion, an inner annular cylindrical portion and an axial end annular plate portion connecting therebetween. Thereafter, the blank is subjected to ironing to form a radial annular rim on the outer surface of the outer annular cylindrical portion at the axial end, and also subjected to cutting-away and bending processes to cut away the outer edge of the inner annular cylindrical portion and to bend the resultant annular thin wall portion radially inwardly so that a radial flange is formed. The resultant magnetic rotatable member has an annular portion defined by the three portions in which an electromagnet should be stationarily contained, the radial annular rim for increasing the magnetic friction surface area and the radial flange for a stopper of a bearing on which the rotatable member should be mounted. The magnetic rotatable member has a high accurate dimension without machining.