A pedestrian conveyor includes a torsional vibration damper system, the torsional vibration damper system including a shaft, a cylindrical housing attached to the shaft and being configured to dampen vibrations of the shaft, a first gear, and a second gear.

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.

A method for protecting a dual mass flywheel DMF, by detecting, when the engine in running, that the DMF is entering into resonance, the DMF being arranged between an internal combustion engine and a gearbox of a vehicle, comprising the following steps: Determining the average rotational speed (Vvil.sub.moy) of the crankshaft, over time, over a predetermined given period, as a first parameter constituting a risk of the DMF entering into resonance, Measuring the maximum instantaneous rotational speed and the minimum instantaneous rotational speed of the crankshaft, the difference defining the maximum amplitude (Amp.sub.Vvil) of the rotational oscillations of the crankshaft, over the period, as a second parameter constituting a risk of the DMF entering into resonance, Detecting when the DMF is entering into resonance from a determined combination of values of the first and second parameters, over the period, limiting or cutting off the fuel injection in the cylinders after said detection.

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 damper device according to one embodiment, for example, includes: a rotating member that is rotatable about a rotational axis, the rotating member including a base portion that is plate-like and support portions that is attached to the base portion and extends in an axial direction of the rotational center; and a plurality of weight members disposed partially overlapping each other in the axial direction, the weight members being provided with tracks in respective overlapped parts of the weight members, the tracks guiding the support portion to be swingable with respect to the rotating member, wherein the support portion is shared in the tracks provided in the weight members.

A centrifugal pendulum having a pendulum flange, a first pendulum mass and a second pendulum mass and a spring arrangement, wherein the first pendulum mass and the second pendulum mass are positioned side-by-side in the circumferential direction, wherein the first pendulum mass is coupled with the pendulum flange by a first slotted guide and the second pendulum mass is coupled with the pendulum flange by a second slotted guide. The first slotted guide guides the first pendulum mass along a first oscillation path and the second slotted guide guides the second pendulum mass along a second oscillation path in an oscillating motion. The spring arrangement at least partially couples the first pendulum mass with the second pendulum mass, wherein at least one of the two pendulum masses has a receptacle. The spring arrangement includes a spring element and a protective device, wherein the protective device is positioned at least partially in the receptacle of the pendulum mass.

Vibration absorbers comprising torsional viscous damper of the tube-type are tuned using one or more elastic members to improve the ability of the vibration absorbers to reduce problematic torsional vibrations. The torsional stiffness of the vibration absorbers is designed to meet a requirement between the frequency to be removed and the polar moment of inertia of the tube-type damper.

A damper (10) includes a housing (11) and a rotor (16) combined with the housing (11) so as to be capable of rotating relative to the housing (11). The damper (10) includes an attenuating medium (90) filled in a rotation area inside the housing (11) wherein the rotor (16) rotates, and added with viscoelasticity by a viscoelasticity treatment; and an enclosure portion (80) provided outside the rotation area of the rotor (16), and communicating with the rotation area.

A dynamic vibration absorbing device for an automobile can be on an output-side member of a torque converter. The dynamic vibration absorbing device includes a rotary member, a mass part, and an elastic member. The rotary member is fixed to the output-side member. The rotary member can be rotated about a rotational center of the output-side member. The mass part includes a first accommodation part. The mass part is for attenuating vibration of the output-side member by rotating about the rotational center relative to the rotary member. The elastic member is held by the first accommodation part. The elastic member elastically couples the rotary member and the mass part in a rotational direction. The elastic member is for generating a hysteresis torque by sliding against the first accommodation part in rotation of the rotary member.

A damper device according to one embodiment, for example, includes: a rotating member that is rotatable about a rotational axis, the rotating member including a base portion that is plate-like and support portions that is attached to the base portion and extends in an axial direction of the rotational center; and a plurality of weight members disposed partially overlapping each other in the axial direction, the weight members being provided with tracks in respective overlapped parts of the weight members, the tracks guiding the support portion to be swingable with respect to the rotating member, wherein the support portion is shared in the tracks provided in the weight members.