摘要 |
A rear frame has a fastening portion, which radially extends from an outer peripheral surface of the rear frame and receives a fastening force of a through bolt. A circuit board, which includes a control circuit, is installed to an axially outer surface of a main body of the rear frame. A reinforcing portion is provided in the fastening portion to limit deformation of the main body of the rear frame, which is induced by the fastening force of the through bolt. |