A crankshaft arrangement for an internal combustion engine includes a crankshaft, a torsional vibration damper having a primary mass and a flywheel, wherein the primary mass is connected fixedly to the crankshaft, and the flywheel and the primary mass are coupled via a viscous fluid. The torsional vibration damper is attached to an output end of the crankshaft. The primary mass is coupled to a secondary coupling via an elastomer coupling ring. The torsional vibration damper is coupled to the secondary coupling via a feedback device. The feedback device has a negative stiffness.

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.

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.

A torsional vibration damper with a housing defining an annular space. A cover is mounted on the housing. The cover and the housing define an annular working chamber. A first mass inertia ring is disposed inside and configured to rotated relative to the annular working chamber. A second mass inertia ring is disposed inside the annular working chamber. The second inertia mass ring is configured to rotate inside the annular working chamber independently with respect to the first inertia mass ring. A viscous damping media is disposed inside the annular working chamber. A hub is configured to extend from the housing in an axial direction. The hub is configured for attaching the damper to a crankshaft

Airfoil vibration damping apparatus are disclosed. An example apparatus includes a metallic airfoil including a cavity, and a dilatant material disposed in the cavity to dampen vibrations of the metallic airfoil.

Airfoil vibration damping apparatus are disclosed. An example apparatus includes a metallic airfoil including a cavity, and a dilatant material disposed in the cavity to dampen vibrations of the metallic airfoil.

A crankshaft assembly which is designed for a reciprocating-piston machine of an internal combustion engine includes a crankshaft, a torsional vibration damper for damping resonance torsional vibrations of the elastic torsion modes of the crankshaft, and an output. The torsional vibration damper has a primary mass inertia and a secondary mass inertia, the primary mass inertia being rigidly connected to a crankshaft and the secondary mass inertia being coupled as a seismic mass with a viscous liquid to the primary mass inertia. The torsional vibration damper is configured to assume the function of a flywheel for reducing rotational non-uniformity in addition to the function of reducing the resonance torsional vibrations of the crankshaft. The torsional vibration damper is attached to an output end of the crankshaft, and the torsional vibration damper forms a centrifugal mass which is divided into a primary mass inertia and a secondary mass inertia, wherein the three functions of a clutch functional section, a flywheel and a torsional vibration damper are integrated into the torsional vibration damper.

A crankshaft assembly which is designed for a reciprocating-piston machine of an internal combustion engine includes a crankshaft, a torsional vibration damper for damping resonance torsional vibrations of the elastic torsion modes of the crankshaft, and an output. The torsional vibration damper has a primary mass inertia and a secondary mass inertia, the primary mass inertia being rigidly connected to a crankshaft and the secondary mass inertia being coupled as a seismic mass with a viscous liquid to the primary mass inertia. The torsional vibration damper is configured to assume the function of a flywheel for reducing rotational non-uniformity in addition to the function of reducing the resonance torsional vibrations of the crankshaft. The torsional vibration damper is attached to an output end of the crankshaft, and the torsional vibration damper forms a centrifugal mass which is divided into a primary mass inertia and a secondary mass inertia, wherein the three functions of a clutch functional section, a flywheel and a torsional vibration damper are integrated into the torsional vibration damper.

A vibration damping device for use with a downhole tool having a tool axis may comprise a device housing mechanically coupled to the downhole tool, wherein the device housing defines a receptacle having a volume and an inner surface; an inertia element movably supported in the receptacle and having a volume, a mass, and a non-zero moment of inertia about the tool axis; wherein the inertia element volume is greater than the receptacle volume and an interstitial volume is defined between the inertia element and the receptacle, and wherein the interstitial volume is occupied by a fluid or an elastomer. The device may include a longitudinal bearing and/or a radial bearing between the inertia element and the receptacle. The device may also include a pressure compensation device in fluid communication with the receptacle and positioned within or an integral part of the device housing.

A viscous torsional-vibration damper has a damper housing with an axis of rotation, an annular working chamber filled with a damping medium, an inertia ring arranged inside the working chamber, and a cover for media-tight closure of the working chamber. The cover is connected to the damper housing peripherally on one side by a sequence of a butt seam and an overlap seam.