Patent ID: 7602094

Claim:
A rotary electric machine comprising: a stator for generating a magnetic field therein; a rotor rotating inside the stator and including an armature core and armature coils held in the armature core; and a commutator connected to the rotor for supplying electric current to the armature coils, the commutator including a plurality of commutator segments, each having a brush contact surface held in sliding contact with brushes, and an insulating member unitarily molded with the plurality of commutator segments; wherein each of the commutator segments, having an embedded portion formed with a tab tail and molded to the insulating member, has one axial end formed with a riser portion, radially extending outward from the brush contact surface, to which end portions of the armature coils are electrically connected; and wherein the insulating member has one axial end formed with a large diameter portion, having a larger diameter than that of the brush contact surface, and an increased wall thickness portion, axially extending from the large diameter portion in a direction away from the riser portion, with a sum of axial wall thicknesses of the increased wall thickness portion and the large diameter portion lying in a value two times an axial wall thickness of the riser portion.