Torsional vibration damping device

A torsional vibration damping device, comprising:

• a rotary member that is rotated by a torque;
• an inertial mass that is arranged on a radially outer portion of the rotary member while being allowed to be oscillated by torque pulses in a rotational direction of the rotary member;
• a raceway surface that is formed in the rotary member to which the inertial mass is centrifugally pushed while being allowed to be oscillated by the torque pulses;
• at least one chamber that is formed on the rotary member to hold the inertial mass and the raceway surface in a manner to allow the inertial mass to oscillate in the rotational direction of the rotary member;
• and
• a lubrication oil encapsulated in the at least one chamber;
• wherein a radially outer section of an inner face of the at least one chamber on which an oil film is formed centrifugally is situated at a radially outer side of the raceway surface;
• wherein an oscillating path of the inertial mass is adjusted in a manner such that during oscillation the inertial mass oscillated by one of the torque pulses along the raceway surface will not come into contact with the oil film of the lubrication oil centrifugally adhering to the radially outer section of the inner face of the at least one chamber throughout an entirety of the oscillation path.