ROTATING DEVICE AND ELECTROMAGNETIC CLUTCH

PROBLEM TO BE SOLVED: To prevent noises generated from a bearing by the collision between balls and inner and outer rings by allowing the balls arranged in a single line to be kept in contact with the inner and outer rings at two points respectively. SOLUTION: When engine rotation is transferred to a pulley 1 via a belt 110 and the pulley 1 and a rotor 2 are invariably rotated, the line of action E of the tension D of the belt 110 and the radial center line A of a bearing 3 are displaced in the axial direction of the bearing 3, and an outer ring 32 receives such moment that it is slightly rotated CCW and inclined. A so-called single-line four-point contact ball bearing is used for the bearing 3 so that individual balls 33 are kept in contact with the inner ring 31 at two points. Even when the outer ring 32 is slightly rotated, individual balls 33 are invariably kept in contact with the inner and outer rings 31, 32 at least at one point respectively. Noise generation from the bearing 3 can be reliably prevented.