A damper device includes a first rotor, a second rotor, a plurality of elastic members and a stopper mechanism. The stopper mechanism includes a first stopper hole, a second stopper hole and a plurality of stop members. The first and second stopper holes are provided on both circumferential sides of each of a plurality of first window holes of the second rotor so as to circumferentially extend therefrom. One or both of the first and second stopper holes communicates at one end thereof with each first window hole and extends at the other end thereof to a position radially outside one of a plurality of second window holes of the second rotor. The stop members are fixed to the first rotor. Each stop member axially penetrates each of the first and second stopper holes and is circumferentially movable within each of the first and second stopper holes.

A vibration damping device for a machine tool spindle is provided. An annular support plate is mounted at a lower portion of a distal end of the spindle, a plurality of support bars is fixed to the support plate in a vertical direction and installed in a longitudinal direction of the spindle adjacent to an outer periphery of the spindle, a pair of weight disks stacked by a plurality of arc-shaped disks made of a tuned mass member is fixed to be in close contact with the outer periphery of the spindle, facing each other, and a damping sheet made of an elastic member is inserted between the outer periphery of the spindle and the weight disks. The vibration damping device of the present invention may maximize a vibration damping effect by installing the vibration damping device at a position closest to the spindle where a vibration occurs. Furthermore, the vibration damping device of the present invention may effectively attenuate a variety of vibration phenomena having various resonant frequencies of a machine tool spindle by constituting the vibration damping device in a plurality of modular types which have different resonant frequency bands, respectively.

A damper device includes a first rotor, a second rotor, a plurality of elastic members and a stopper mechanism. The stopper mechanism includes a first stopper hole, a second stopper hole and a plurality of stop members. The first and second stopper holes are provided on both circumferential sides of each of a plurality of first window holes of the second rotor so as to circumferentially extend therefrom. Each of the first and second stopper holes communicates at one end thereof with each first window hole and extends at the other end thereof to a position radially outside one of a plurality of second window holes of the second rotor. The stop members are fixed to the first rotor. Each stop member axially penetrates each of the first and second stopper holes and is circumferentially movable within each of the first and second stopper holes.

A mass damper system is provided with a damper mass carrier at which damper masses are relatively movably received and a stop is fastened. The damper masses are arranged radially outwardly of the stop and provided at their radial sides facing the stop with contact areas that cooperate with profile areas provided at the stop and which are provided at radial sides facing the damper masses. The stop has at least one stop carrier and at least one stop damper connected to the stop carrier via a radial securing element.

A mass damper system is provided with a damper mass carrier at which damper masses are relatively movably received and a stop is fastened. The damper masses are arranged radially outwardly of the stop and provided at their radial sides facing the stop with contact areas that cooperate with profile areas provided at the stop and which are provided at radial sides facing the damper masses. The stop has at least one stop carrier and at least one stop damper connected to the stop carrier via a radial securing element.

The invention relates to a flywheel for stabilising the position of a spacecraft, comprising a hub means (1) for fastening the flywheel, a flywheel ring (4), which externally surrounds the hub means (1) circumferentially at a distance, a support means (3) for supporting the flywheel ring (4) on the hub means (1), and a vibration damping device (6, 8) having a tuned mass damper means (8) which is axially movable back and forth relative to the flywheel ring with respect to a rotation axis of the flywheel.

In a damper device, a dynamic damper is coupled to a first intermediate member, first and second inner-side springs that act in series with each other are straight coil springs disposed between a second intermediate member and a driven member so that outward movement of the springs in a radial direction of the damper device is restricted at respective both ends, and a gap is formed between each body portion of the first and the second inner-side springs and the second intermediate member or a spring abutment portion of the driven member.

A dual deflection ring system includes a pair of components that rotate relative to one another about an axis of rotation. One or more deflection rings are disposed between the components. The deflection ring(s) include two sets of pockets configured to provide two levels of compressibility in-series between the components. The two sets of pockets project radially relative to the axis of rotation and are compressible between the components.

A passive oscillation damper (8), in particular for a switch cabinet (2), includes a supporting structure (12) having a longitudinal direction (y) and a transverse direction (x) and with a central oscillating mass (14) mounted by means of spring elements (20, 22, 24, 26) so as to be able to oscillate in the longitudinal direction (y) and in the transverse direction (x). At least one peripheral oscillating mass (40, 42) is mounted on the central oscillating mass (14) so as to be slidable in the longitudinal direction (y) and to be movable relative to the central oscillating mass (14). At least one peripheral oscillating mass (44, 46) is mounted on the central oscillating mass (14) so as to be slidable in the transverse direction (x) and to be movable relative to central oscillating mass (14).

A self-adaptive torsional vibration reducer is provided, which includes an inner casing, an outer casing and resonance bodies provided between the inner casing and the outer casing. Each of the resonance bodies includes a mass-block and constraining springs supporting the mass-block between the inner casing and the outer casing. The resonance bodies are provided in pairs and are symmetrically distributed around a center of the rotating shaft. In a case that a frequency of an excitation force on the rotating shaft is coincided with the resonance frequency, the resonance bodies absorb torsional vibration energy at the frequency to reduce vibration. A diesel engine including the self-adaptive torsional vibration reducer is also provided.