A torsional vibration damper that can reduce collision noise of an inertia body when a rotary member is stopped, and a control device therefore. In the torsional vibration damper, a rotary member is mounted on an output shaft of an engine such that none of rolling masses is situated within a predetermined angle range above a rotational center axis of the rotary member when the engine is stopped. Therefore, when the engine is stopped, the inertia body will not be supported by only one of the rolling masses situated within the predetermined angle range.

A pump system may include a pump, a driveshaft, driving equipment, and a vibration dampening assembly configured to reduce pump-imposed high frequency/low amplitude and low frequency/high amplitude torsional vibrations. The pump may have an input shaft connected to the driveshaft. The driving equipment may include an output shaft having an output flange connected to the driveshaft. The driving equipment may be configured to rotate the driveshaft to rotate the input shaft of the pump therewith. The vibration dampening assembly may include one or more flywheels operably connected to the input shaft and configured to rotate therewith.

A centrifugal pendulum damper in which a rolling mass can be lubricated by a simple structure without limiting vibration damping performance. The pendulum damper comprises: a rotary member; an inertia body arranged concentrically with the rotary member; a rolling mass held in a retainer on an outer circumference of the rotary member; a recess formed on an inner circumference of the inertia body; and a raceway surface formed on an inner circumference of the recess to which the rolling mass is contacted. In the centrifugal pendulum damper, oil remaining in the recess is discharged out of the recess through an oil passage.

Methods and systems for adjusting a tuning state of a pendulum damper are provided. In one example, an engine system is provided that includes a crankshaft coupled to a plurality of pistons in a plurality of cylinders. The crankshaft includes a plurality of pendulums coupled to a plurality of cheeks and a pendulum tuning mechanism coupled to an associated pendulum included in the plurality of pendulums or coupled to an associated pendulum in a torque converter and configured to tune damping characteristics of the associated pendulum based on an engine order.

A pump system may include a pump, a driveshaft, driving equipment, and a vibration dampening assembly configured to reduce pump-imposed high frequency/low amplitude and low frequency/high amplitude torsional vibrations. The pump may have an input shaft connected to the driveshaft. The driving equipment may include an output shaft having an output flange connected to the driveshaft. The driving equipment may be configured to rotate the driveshaft to rotate the input shaft of the pump therewith. The vibration dampening assembly may include one or more flywheels operably connected to the input shaft and configured to rotate therewith.

A dynamic damper includes a resilient material, an annular mass and a metallic split ring. The resilient material has a central bore formed therethrough dimensioned to receive a vehicle axle. The central bore defines a first inner diameter. The annular mass is surrounded and embedded in the resilient material. The annular mass defines a second inner diameter greater than the first inner diameter. The metallic split ring is embedded within the resilient material along a portion of the surface of the central bore with locking protrusions extending into the central bore. Ends of the locking protrusions define a third inner diameter smaller than the first inner diameter. The locking protrusions is dimensioned to extend into openings in the vehicle axle locking the metallic split ring, the resilient ring and the annular mass to the vehicle axle.

A pump system may include a pump, a driveshaft, driving equipment, and a vibration dampening assembly configured to reduce pump-imposed high frequency/low amplitude and low frequency/high amplitude torsional vibrations. The pump may have an input shaft connected to the driveshaft. The driving equipment may include an output shaft having an output flange connected to the driveshaft. The driving equipment may be configured to rotate the driveshaft to rotate the input shaft of the pump therewith. The vibration dampening assembly may include one or more flywheels operably connected to the input shaft and configured to rotate therewith.

A damping device is described that is designed to counter the transmission of vibrations to a further element and comprises: a beam element, which extends mainly parallel to an axis, is constrained to the further element and is designed to flexurally oscillate, in use, in a plane parallel to the axis to counter the transmission of vibrations to the further element; an actuator, which comprises a transmission element operatively connected to the beam element and extending mainly along the axis; the actuator being controllable to apply a direct tensile or compressive load along the axis on the transmission element that is variable according to the frequency of the vibrations to be dampened.

Vibration isolators can be dimensioned for securement between a rotational motion source and a rotational motion target. The vibration isolators can include a first end member and a second end member supported in substantially-fixed axial position but axially-rotatable relative to the first end member. An intermediate member can be disposed between and operatively engaging the first and second end members. A rotational motion-to-axial motion conversion system is operatively disposed between the intermediate member and the first end member such that rotation of the intermediate member and the second end member generates axial displacement of the intermediate member relative to the first and second end members. A biasing element can be operatively disposed between the intermediate member and one or more of the first and second end members to bias the intermediate member in an axial direction. Rotary power transmissions or system are also included.

A torsional vibration damper in which a vibration damping performance is enhanced without increasing a manufacturing cost. A torsional vibration damper damps torsional vibrations by a relative rotation between a rotary member and an inertia body. Hardness of the contact surface of any one of the inertia body and a rolling mass is harder than the contact surface of the other one. Smoothness of the contact surface of any one of the inertia body and the rolling mass is smoother than the contact surface of the other one.