ELECTROMAGNETIC CLUTCH AND METHOD FOR PRODUCING ARMATURE FOR ELECTROMAGNETIC CLUTCH

摘要

Provided is an electromagnetic clutch whereby the contact area between an armature and a rotor can be increased to thereby increase the attractive force between the armature and the rotor, without increasing the outer diameters of the armature and rotor. An electromagnetic clutch in which a rotor contact surface (46a) of the armature (42) is segmented into a plurality of ring shapes in the radial direction by annular grooves (44) for magnetic flux cutoff formed concentrically with the armature (42), and magnetic force of an electromagnetic coil attracts the armature (42) to a contact surface of the rotor (43) to integrally bond the two and transmit power. The armature (42) is manufactured through a material manufacture step for obtaining an armature material (42) in which are formed the grooves (44) of a width (w1), and a narrowing processing step for narrowing the width of the grooves to a width (w2) less than (w1) by applying a pressing force to a pressed section (47) on the periphery of the grooves (44) of the armature material (42) and causing a plastic flow to occur in the planar direction of the armature material (42).