A first end contact portion of a first frame end contacts one end surface of a stator core. A second end contact portion of a second frame end contacts the other end surface of the stator core and includes an inner tubular part, which contacts the other end surface of the stator core, and a fixing part, which projects radially outward from the inner tubular part and contacts the other end surface. A through-bolt is threaded into the fixing part. An outer diameter of the one end surface is smaller than an outer diameter of an opposing surface of the first end contact portion. An outer diameter of an opposing surface of the inner tubular part is smaller than an outer diameter of the other end surface. A yoke of the stator core includes a relief groove, into which a portion of the through-bolt is fitted.