Torsional vibration damper

A torsional vibration damper, comprising:

• a rotary member that rotates by being inputted with a torque;
• an inertia body disposed on an outside in a radial direction of the rotary member so as to rotate freely in a circumferential direction centered on a rotational center axis of the rotary member;
• and
• a rolling member that couples the rotary member and the inertia body in a relatively-rotatable manner,
• wherein torsional vibration of the rotary member is suppressed by relative rotation of the inertia body with respect to the rotary member,
• the rotary member includes in its outer circumferential section a plurality of support sections by which the rolling member is restricted in a rotating direction of the rotary member and is engaged movably in the radial direction of the rotary member, and
• the inertia body includes:
• a pair of mass sections that project toward both sides in a direction of the rotational center axis of the rotary member with respect to the rotary member;
• and
• a pair of raceway surfaces that are respectively provided on an inside in the radial direction of the pair of mass sections in a manner enabling the pair of raceway surfaces to be abutted on by the rolling member, the pair of raceway surfaces having a center of curvature in a place deviating from a rotational center of the rotary member.