Occurrence of secondary resonance in a dynamic damper device of a lock-up device is inhibited to improve effectiveness of the dynamic damper device. The lock-up device includes a drive plate, a driven plate coupled to a turbine, an intermediate member, a plurality of outer peripheral side and inner peripheral side torsion springs, and a dynamic damper device. The intermediate member is disposed between the outer peripheral side torsion springs and the inner peripheral side torsion springs. The outer peripheral side torsion springs elastically couple the drive plate and the intermediate member in a rotational direction. The inner peripheral side torsion springs elastically couple the intermediate member and the driven plate in the rotational direction. The dynamic damper device includes an inertia ring coupled to the intermediate member.

A damper apparatus for an alternator pulley uses a mass inertia body installed on a same axis as the alternator pulley to promote absorption of vibrations and removal of noises occurring due to a resonance of the alternator.

A torsional vibration damper for transferring torque between a first and a second rotatable element, having a rotatable pressure plate to transfer the torque from the first element, a rotatable output element to transfer the torque to the second element, and a vibration damper element to transfer the torque between the pressure plate and the output element, where the vibration damper element includes an energy-storing spring system. A driving element is formed in a single piece on the pressure plate to fit against the spring system.

A number of variations may include a torsional vibration damper having an input side, having an output side and having an energy store for the rotationally elastic coupling of the input and output sides in a circumferential direction, wherein, on the input or output side, there is arranged a mass part that is rotatable relative to the input or output side counter to the restoring force of a restoring apparatus.

The invention relates to a tuned mass damper or vibration damper which, with the aid of an assembly (2) of a plurality of stacked, specially shaped or bent leaf springs (2.1), can be adapted over a certain range to the disturbance frequencies acting on a component to be damped or of the vibration system to be damped, the position of the damper mass (1, 34) being changed essentially only slightly. The invention relates in particular to one- and two-dimensionally effective tuned mass dampers. The tuned mass dampers according to the invention are suitable in particular for installations, vehicles and machines that undergo frequent changes in rotational speed, resulting frequently in disturbance frequencies that become noticeable, in particular, in the form of structure-borne sound, or other vibrations.