As illustrated in FIG. 7, the inner circumferential surface 26a of the rotor outer edge 26 arranged on the outer side in the radial direction of the yoke 22 has a recess 91. The recess 91 is larger than the protrusion 163 of the caulking dowel portion 160 protruding to the outer side in the radial direction from the outer circumferential surface 22c of the yoke cylindrical portion 22a when viewed in the axial direction. The six recesses 91 are arranged at intervals of 60° in the circumferential direction. Therefore, the six recesses 91 and the protrusions 163 of the caulking dowel portion 160 protruding from the outer circumferential surface 22c can oppose each other in the radial direction. Each of the recesses 91 has an opposing portion 92 that opposes the protrusion 163 protruding from the outer circumferential surface 22c in the circumferential direction. Each of the opposing portions 92 overlaps the protrusion 163 of the caulking dowel portion 160 protruding from the outer circumferential surface 22c in the circumferential direction.

The six recesses 91 and the protrusions 163 of the caulking dowel portion 160 protruding from the outer circumferential surface 22c can oppose each other in the radial direction, and each of the opposing portions 92 overlaps the protrusion 163 protruding from the outer circumferential surface 22c in the circumferential direction, and thus, the yoke 22 and the rotor outer edge 26 are positioned relative to each other in the circumferential direction. Therefore, when the rotor 13 rotates, the yoke 22 and the rotor outer edge 26 rotate integrally.