Patent ID: 7204761

Claim:
A torsional vibration damper comprising: a primary mass adapted to be coupled to an engine crankshaft for rotation about a rotational axis of the engine crankshaft, the primary mass defining a substantially ring-shaped chamber that is divided into at least two portions; a secondary mass relatively rotatably connected to the primary mass and connectable with a clutch; and a damping unit for coupling the primary and secondary masses to each other in a rotationally elastic manner, wherein the damping unit comprises: a plurality of elastic members situated in series and disposed one after the other within each divided portion of the ring-shaped chamber; a pair of end guides slidably disposed within each divided portion of the ring-shaped chamber and supporting outer ends of the end elastic members among the plurality of elastic members; a wedge-shaped friction member slidably disposed between neighboring elastic members in each divided portion of the ring-shaped chamber, the wedge-shaped friction member comprising an inner wedge and an outer wedge that are elastically supported by the neighboring elastic members such that the outer and inner wedges move in opposite directions; and a concentrated mass friction member slidably disposed between the neighboring elastic members in each divided portion of the ring-shaped chamber and comprising a concentrated mass at a center portion thereof.