A method determines a service life condition of a torsional vibration damper or absorber having a primary mass and a secondary mass, and a working chamber arranged between the primary mass and the secondary mass that is filled with a viscous damping medium. The vibration damper is arranged on a crankshaft of an engine in order to dampen or eliminate torsional vibrations of this crankshaft. The method includes: operating the engine; determining at least one operating parameter of the engine; simulating a temperature distribution of the viscous damping medium in the working chamber; and determining a lifetime condition of the vibration damper based on the operating parameter of the engine and the result of simulating the temperature distribution of the viscous damping medium.

One embodiment described herein is a damper for a rotor system, the damper comprising a cylindrical housing having a hollow interior; a piston disposed within the hollow interior and extending along a central axis of the housing; a first attachment member disposed on a first end of the damper and connected to the housing; a second attachment member disposed on a second end of the damper and connected to the piston; and a conductive cover wrapped around a portion of an exterior surface of the housing between the first attachment member and the second attachment member.

Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.

An apparatus for damping vibrations includes an inertial mass disposed in a cavity in a rotatable downhole component, the rotatable component configured to be disposed in a borehole in a subsurface formation, such as a resource bearing formation, the inertial mass coupled to a surface of the cavity by a damping fluid and configured to move within the cavity relative to the downhole component. The apparatus also includes a damping fluid disposed in the cavity between the inertial mass and an inner surface of the cavity, where rotational acceleration of the rotatable downhole component causes shear in the damping fluid to dissipate energy from rotational acceleration of the rotatable downhole component and causing the rotational acceleration to be reduced.

An articulated working machine vehicle, such as an articulated hauler, including a front section and a rear section pivotally connected via a connection arrangement configured to control a pivot angle between the front and rear sections for steering of the vehicle, the connection arrangement further being configured to allow the front and rear sections to rotate in relation to each other about a longitudinal axis of the vehicle. The connection arrangement comprises a rotation damper device arranged to transfer dampened relative rotation between the front section and the rear section of the vehicle.

A vibration isolating coupler including a first coupler portion, a second coupler portion including an external surface and an internal surface portion, and a vibration isolating portion extending between the first coupler portion and the second coupler portion. The vibration isolating portion including a first solid annular portion and a second solid annular portion. The vibration isolating portion including a plurality of slots extending from the first solid annular portion toward the second solid annular portion forming a plurality of vibration isolating elements. Each of the plurality of vibration isolating elements is disconnected from adjacent ones of the plurality of vibration isolating elements by a corresponding one of the plurality of slots. The plurality of vibration isolating elements enabling torsional rotation of the first coupler portion relative to the second coupler portion.

An isolator comprising a pulley having a pulley stop, a plate attached to the pulley, a shaft, the pulley journalled to the shaft, a torsion spring attached to the shaft, a damping member attached to the torsion spring, the damping member disposed between the plate and the pulley, and the damping member compressing a damping fluid against the pulley stop.

An isolator comprising a pulley having a pulley stop, a plate attached to the pulley, a shaft, the pulley journalled to the shaft, a torsion spring attached to the shaft, a damping member attached to the torsion spring, the damping member disposed between the plate and the pulley, and the damping member compressing a damping fluid against the pulley stop.

Disclosed is a hydraulic damping device level riding platform with adjustable resistance, which comprises a frame body, a shaft mechanism, a flywheel and a hydraulic damping mechanism, the shaft mechanism is arranged on the frame body, one end of the shaft mechanism is connected with the hydraulic damping mechanism and another end of the shaft mechanism is connected with the flywheel. The hydraulic damping mechanism comprises: a cavity; a rotating disc provided with blades, the rotating disc is arranged in the cavity; and a liquid level height adjusting mechanism movably connected inside the cavity to control a liquid level height in the cavity. The liquid level height of the liquid in the cavity is controlled through the liquid level height adjustment mechanism, so as to realize the control of the resistance of the rotating disc to the liquid.

A stabilizer (10) includes a base (20) fixed on a motion reduction target (1); a gimbal (40) supported by the base to be rotatable around a first axis (RA); a damper mechanism (30) disposed to damp a relative rotary motion of the gimbal (40) to the base (20); a flywheel (50) disposed to be rotatable around a second axis (RB) orthogonal to the first axis (RA). The damper mechanism (30) is a passive-type damper mechanism. A first value (D1) of a damping coefficient (D) of the damper mechanism (30) when an angular velocity of the gimbal (40) is a first angular velocity is larger than a second value (D2) of the damping coefficient (D) of the damper mechanism (30) when the angular velocity of the gimbal (40) is a second angular velocity smaller than the first angular velocity.