Patent ID: 7015607

Claim:
An AC generator for a vehicle comprising a rotator mounted in a casing body so as to be freely rotatably supported through a rotational shaft, a cooling fan equipped to the rotator so as to vent outside air into a main body of the generator, and positive-electrode side and negative-electrode side support members disposed between the casing body and the cooling fan for supporting one-way conducting elements at the positive-electrode side and the negative-electrode side respectively, the positive-electrode side support member and the negative-electrode side support member being arranged on substantially the same plane perpendicular to the rotational shaft, wherein the inner peripheral surface of one of the positive-electrode side support member and the negative-electrode side support member which is located at a farther position from the rotational shaft is inclined so that the dimension in the radial direction thereof is increased from one end surface of the support member concerned at the casing body side to the other end surface of the support member concerned at the fan side, wherein the end surface at the casing body side of the support member located at a farther side from the rotational shaft is firmly fixed to the casing body, and the casing body on which the support member is fixed is provided with cooling fins projecting in the rotational shaft direction and inwardly in the radial direction, and wherein the ratio 1 c / 1 b of a length 1 c in the radial direction of the fixed end surface and a length 1 b from the outer diameter of the fixed end surface to the inner diameter of the fins satisfies 0.5< 1 c / 1 b <0.9.