A mounting structure includes a damper (10) consisting of two damper pieces (16) capable of being disposed around a rotary shaft (14) and two sets of bolts (13a) and nuts (13b). The damper (10) is mounted on the rotary shaft (14) by connecting the two damper pieces (16) through the bolts (13a) and nuts (13b). Each of the damper pieces (16) has a mass portion (17a) having an inner peripheral surface (20) diverging toward an opening end and being out of contact with the rotary shaft (14) and a mounting portion (17b) having rigidity lower than that of the mass portion (17a) and mounted on the rotary shaft (14).
