An arrangement reduces oscillation of an oscillatory structure. The arrangement has: a structure having at least one mode in at least one direction; and an oscillation-reducing device. The oscillation-reducing device includes a housing on the structure; a cavity; and a body. The body is configured to make impact contact with a first surface portion and a second surface portion of an inner wall of the housing and disposed is in the cavity such that the body can make impact contact with the first surface portion and the second surface portion of the inner wall of the housing at least temporarily for as long as the structure is excited in the at least one mode in the at least one direction. The first surface portion or the second surface portion of the inner wall of the housing has a curved profile.

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 vibration damping device including a supporting member rotating with a rotation element around a rotation center of the rotation element; a restoring force generation member coupled to the supporting member to transfer torque to and from the supporting member and configured to swing with rotation of the supporting member; and an inertia mass body coupled to the supporting member via the restoring force generation member and swinging around the rotation center with the restoring force generation member with rotation of the supporting member, in which the restoring force generation member swings around a swing center so that a relative position with respect to the inertia mass body does not change, and a distance between a center of gravity of the restoring force generation member and the swing center changes with a change in a swing angle of the restoring force generation member with respect to the inertia mass body.

A hybrid module for a motor vehicle power train, including an input side for connecting to an internal combustion engine, an output side for connecting to a drive wheel, an electric drive motor comprising a stator and a rotor and a torque transfer device arranged between the roto and the output side. The transfer device is designed to reduce rotational irregularity.

A fluid transmission device is capable of transmitting power between a first rotating element and a second rotating element by kinetic energy of a fluid and capable of transmitting power between the first rotating element and the second rotating element via a lock-up clutch. The device includes a first damping mechanism and a coupling mechanism. The first damping mechanism is disposed in a path for transmitting power between the first rotating element and the second rotating element via a lock-up clutch for restraining variations in rotation of the second rotating element. The coupling mechanism is configured to release the first damping mechanism from the first rotating element and the second rotating element when the lock-up clutch is released and couple the first damping mechanism to the first rotating element and the second rotating element when the lock-up clutch is engaged.

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 vibration damping device includes a support member that rotates, together with a rotary element to which torque from an engine is transmitted, about a center of rotation of the rotary element, a restoring force generation member that is coupled to the support member to transmit torque to and receive torque from the support member and that is swingable along with rotation of the support member, and an inertial mass body that is coupled to the support member via the restoring force generation member and that swings about the center of rotation in conjunction with the restoring force generation member along with rotation of the support member. The support member is disposed between at least a part of the restoring force generation member and at least a part of the inertial mass body in an axial direction.

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.

A torsional vibration damper having improved durability, whose vibration damping performance is ensured irrespective of machining error. The torsional vibration damper comprises: a rotary member rotated by torque; a retainer formed on the rotary member to protrude radially outwardly; a rolling member held in the retainer while being allowed to reciprocate in the retainer; and an inertia body arranged around the rotary member while being allowed to rotate relatively to the rotary member. An elastic member is arranged on any one of inner surfaces of the retainer to push a shaft of the rolling member toward the other one of the inner surfaces of the retainer.

A torsional vibration damper having improved abrasion resistance at a portion of a rotary member to which a rolling mass is contacted, and a manufacturing method thereof. The torsional vibration damper comprises: a rotary member; an inertia body oscillating around the rotary member; and a retainer formed on the rotary member to hold a rolling mass between a pair of stoppers. A hardness of an inner surface of at least one of the stoppers is increased higher in a radially outer portion than in a radially inner portion, within a reciprocating range of the rolling mass.