Patent ID: 7859161

Claim:
A rotational electric machine comprising: a cylindrical yoke; and a field winding connected to an inner surface of the cylindrical yoke with a pole core having a boss portion and a supporting brim, the field winding being formed by coupling a formed coil to a bobbin, wherein: the bobbin comprises: a first flange for insulating the formed coil from the inner surface of the cylindrical yoke; a second flange for insulating the formed coil from the supporting brim of the pole core; and a pipe portion connecting the first flange and the second flange, either of the first flange or the second flange is formed all around the pipe portion, while the other of the first flange or the second flange is formed to extend only in a lateral direction of the pipe portion, the lateral direction being perpendicular to an axial direction of the cylindrical yoke, and a V-shaped cutout is formed at each axial end wall of the pipe portion, the V-shaped cutout being open at the other of the first or the second flange, wherein the V-shaped cutout is enlarged from the first flange to the second flange, and the first flange is configured to be connected to the inner surface of the cylindrical yoke.