To facilitate attaching work in a device for attaching an excitation apparatus.

A fitting projection 32 as the side part of the excitation apparatus 10 is fitted to a plate 30, which is provided as the side part of a wheel and an apparatus body 12 of the excitation apparatus 10 is rotated. A second tapered member 72 is drawn in the apparatus body 12, accompanied by the rotation of the apparatus body 12, to be fitted in the taper gap between tapered surfaces 84 and 92. A first tapered member 70 is expanded in its diameter, and an outer peripheral surface 60 is fitted tightly to the inner peripheral surface 56 of the plate 30 and the apparatus body 12 of the excitation apparatus 10 is clamped to the plate 30. Since the apparatus body 12 can be clamped to the plate 30 by its rotation, attaching work is facilitated.