Patent ID: 7535140

Claim:
An alternator to be mounted on a vehicle and adapted to be driven by an engine of the vehicle via a belt, comprising: a rotor driven by the engine for generating rotating magnetic fluxes; a stator having armature windings for generating electromotive forces in response to the rotating magnetic fluxes; a housing by which the stator is fixedly supported; a pulley fixedly secured to the rotor to transfer belt drive power to the rotor; bearings fixedly supported by the housing and rotatably supporting the rotor; and a bush made of an iron member and formed to have a cylindrical form with a cylindrical inner surface and an outer surface from which a plurality of protrusions extend, the bush fixedly secured to the housing at the outer surface thereof by casting formation; wherein one of the bearings, placed closer to the pulley, comprises an inner race, an outer race and rolling elements, all of which are made of iron members, and the outer race is press fitted to the inner surface of the bush with given interference.