Patent ID: 6409004
Filing Date: 2002-06-25
Classification: F16D

Abstract:
An electromagnetic clutch comprising:a clutch rotor having a flange portion; an armature opposed to the flange portion; and an exciting coil held in the clutch rotor and adapted to form in the clutch rotor and the armature a magnetic flux for attaching the armature to the flange portion when supplied with current, the flange portion including arcuate outside slits and arcuate inside slits, formed individually on the respective circumferences of a plurality of concentric circles, and a plurality of magnetic pole portions defined in the radial direction of the flange portion by the outside slits and the inside slits, the flange portion having a step portion and a concave surface continuous with the step portion, formed in a region corresponding to a specific one of the magnetic pole portions formed between the outside slits and the inside slits so as to be situated more remote from the armature than the other magnetic pole portions, the step portion serving to restrain the specific magnetic pole portion from touching the armature when the magnetic flux is formed.