Mass portions of torsional dampers are annular surrounding corresponding elastic portions. The mass portion of the torsional damper has a first inclined face formed such that the elastic portion deforms in a sheared manner as the mass portion rotates in a rotational direction with respect to a companion flange and the elastic portion partially deforms in a compressed manner as the mass portion rotates in a direction other than the rotational direction. The mass portion of the torsional damper has second inclined faces formed such that the elastic portion deforms in a sheared manner as the mass portion rotates in the direction of the rotational axis of the companion flange and the elastic portion partially deforms in a compressed manner as the mass portion rotates in a direction other than the direction of the rotational axis.