A controllable magneto-rheological device includes an annular cylinder formed by inner and outer walls connected at first and second opposing ends and forming an inner shaft configured to receive an operational component of an engine, generator or other device including one or more rotating structures. A magneto-rheological fluid is provided to fill a volume between the inner and outer walls of the annular cylinder. A plurality of electro-magnetic coils are positioned around the outer wall of the annular cylinder. One or more current controllers are coupled to the plurality of electro-magnetic coils for introducing a current through each of the electro-magnetic coils and corresponding magnetic flux through the magneto-rheological fluid. A level of current provided to each of the plurality of electro-magnetic coils directly affects the viscosity of the magneto-rheological fluid and thus the stiffness and damping levels of the controllable magneto-rheological device.

A controllable magneto-rheological device includes an annular cylinder formed by inner and outer walls connected at first and second opposing ends and forming an inner shaft configured to receive an operational component of an engine, generator or other device including one or more rotating structures. A magneto-rheological fluid is provided to fill a volume between the inner and outer walls of the annular cylinder. A plurality of electro-magnetic coils are positioned around the outer wall of the annular cylinder. One or more current controllers are coupled to the plurality of electro-magnetic coils for introducing a current through each of the electro-magnetic coils and corresponding magnetic flux through the magneto-rheological fluid. A level of current provided to each of the plurality of electro-magnetic coils directly affects the viscosity of the magneto-rheological fluid and thus the stiffness and damping levels of the controllable magneto-rheological device.

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.

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.

A torsional vibration damper in the form of a two-mass flywheel for a motor vehicle, the dual-mass flywheel having a primary mass that is connected to the drive shaft of a drive engine in a torsionally rigid manner and revolves therewith, at least one energy storage element, and a secondary mass which is driven in a torsionally flexible manner by the primary mass via the energy storage element. The torque fed into the primary mass via the drive shaft is transmitted to at least one further link of the motor vehicle drive train arranged in a housing via an output shaft of the secondary mass. The primary mass is designed as a rotationally symmetrical hollow body that is concentric to its axis of rotation, open at least on one side, surrounds the secondary mass.

A damping actor selector may be configured to transition a multi-actor damping system from a first damping actor configuration to a second damping actor configuration. The multi-actor damping system may be used in a shock strut assembly to alter a damping curve of the shuck strut assembly. The damping actor selector may be coupled to a metering pin of a shock strut assembly. The damping actor selector may be configured to rotate the metering pin to transition the multi-actor damping system from a first damping actor configuration to a second damping actor configuration. The first damping actor configuration may correspond to a first damping curve. The second damping actor configuration may correspond to a second damping curve. The first damping curve being different than the second damping curve.

A method and system to isolate vibrations, including a first pair of fluid chambers disposed to isolate first vibrations between a first body and a second body, wherein the first vibrations are parallel to a first axis, wherein the first body is a propeller hub, a rotor hub, a pylon attachment, or an engine, and wherein the second body is a propeller shaft, a rotor mast, or a body attachment; a second pair of fluid chambers disposed to isolate second vibrations between the first and second bodies, wherein the second vibrations are parallel to a second axis perpendicular to the first axis; first and second inertia tracks disposed to place the first and second pairs of chambers in fluid communication, respectively; and a plurality of elastic energy storage devices coupled to the first body and the second body and disposed to isolate vibrations between the first and second bodies.

A torsional vibration damper or torsional tuned mass damper having a rotating system having a primary mass, which is arranged, or preferably fixable for conjoint rotation on a rotatable shaft, such as a crankshaft of a motor, for example, in particular an internal combustion engine, and having a secondary mass, which is movable relative to the primary mass. An assembly for vibration dampening and/or tuned vibration dampening of the relative motion between the primary mass and the secondary mass is formed in part outside of the rotating system of the torsional vibration damper or torsional tuned mass damper.

A liquid damper system for restraining vibrations generated in a rotating body includes: a liquid damper which is coaxially rotatable with the rotating body and includes a collision member, the collision member being provided in a casing in which liquid is enclosed and the liquid colliding with the collision member when moving in the circumferential direction; and a relative rotation unit configured to cause the liquid damper to rotate relative to the rotating body. Vibrations of a rotating body are effectively suppressed when a rotating body steadily rotates at a main resonance frequency, in the liquid damper system.