A fluid damper device may include a tube-shaped case with a bottom wall, a tube part and a partitioning protruded part protruded from the tube part, a turning shaft provided with a body part which faces a first end face of the partitioning protruded part and a flange part enlarged to an outer side in the radial direction from the body part and faces a second end face of the partitioning protruded part, a valve body supported on an outer side of the body part, and fluid filled on an inner side of the case. A face of the flange part is provided with a first region structured to contact the partitioning protruded part and a second region where a distance between the second end face and the flange part is set to be wider than the first region along one direction in a circumferential direction.

A fluid damper device may include a tube-shaped case including a bottom wall, a tube part extended from the bottom wall, and a partitioning protruded part protruded to an inner side from an inner peripheral face of the tube part, and a turning shaft including a body part facing a first end face of the partitioning protruded part, and a flange part which is enlarged from the body part and faces a second end face of the partitioning protruded part, a valve body supported by the body part, and fluid filled within the case. The first end face of the partitioning protruded part is provided with a first rib protruded toward the body part and extended in the axial line direction and a second rib protruded toward the body part and extended in the axial line direction at a position separated in a circumferential direction from the first rib.

The present disclosure provides vibratory compactor comprising an active isolation apparatus for reducing a vibration generated during the rotation of an eccentric shaft having an eccentric weight attached thereto. The active isolation apparatus comprises a drum, a propulsion motor configured to rotate the drum, a drive plate disposed between the propulsion motor and the drum in such a way as to be connected to the propulsion motor to transmit a rotating force to the drum, and a drum support configured to rotatably support the drum. The active isolation apparatus further comprises a first active isolation mass disposed between the drum support and the drum, a second active isolation mass disposed between the drive plate and the drum, an eccentric shaft configured to be rotated while penetrating through the first active isolation mass, the drum, and the second active isolation mass, a primary eccentric weight attached to the eccentric shaft inside the drum, an active isolation eccentric weight attached to each of the eccentric shaft inside the first active isolation mass and the second active isolation mass, and a vibration motor configured to rotate the eccentric shaft. In accordance with the active isolation apparatus of the present disclosure, when the eccentric shaft is rotated, a phase of a vibration generated by the active isolation eccentric weights is opposite to that of a vibration generated by the primary eccentric weight, and the vibration generated by the active isolation eccentric weights cancels the vibration generated by the primary eccentric weight.

The present disclosure provides a rotational spring dampener that has a compression limiter, a first disk, and a second disk. The first disk is disposed at a first end of the compression limiter and the second disk is disposed at a second end of the compression limiter, where the second end is opposite the first end. The rotational spring dampener also has a tensile member. The tensile member is connected to the first disk and the second disk. The tensile member is composed of a block copolymer

A damper device includes a retaining plate, a plurality of first spring members and an output plate. The retaining plate has an annular shape. The plurality of first spring members are held by the retaining plate. The output plate is elastically coupled to the retaining plate through the plurality of first spring members. The retaining plate is circumferentially divided into a plurality of divided retaining plate pieces.

A pulley structure may be equipped with an outer rotating body, an inner rotating body, and a coil spring provided between the outer rotating body and the inner rotating body. The coil spring is configured so as to undergo torsional deformation in a diameter-expanding or a diameter-contracting direction, thereby engaging the outer rotating body and the inner rotating body and transmitting torque, and to undergo torsional deformation in the direction opposite the direction in which torque is transmitted, thereby entering a disengaged state in which the coil spring slides with the outer rotating body or the inner rotating body, thus interrupting the transmission of torque. The number of windings of the coil spring is in a range between [M-0.125] and M (both inclusive), where M is a natural number.

The disclosure relates to a torsional vibration damping assembly comprising a deflection mass carder capable of rotation about a rotational axis and deflection masses mounted following one another in a circumferential direction on the deflection mass carrier and deflectable from a basic relative position, wherein the radial position of the deflection masses with respect to the rotational axis changes on deflection from the basic relative position, with each deflection mass being mounted deflectably in both circumferential directions from the basic relative position by coupling formations on the deflection mass carrier, with a resiliently deformable stop formation being provided and assigned to each deflection mass to haft a deflection movement of the deflection mass once a stop deflection has been reached, with the resiliently deformable stop formation comprising a resilient stop material which is fixedly mounted with respect to the deflection mass carder, with the following ratio R being applicable in the assignment to each deflection mass: R=VE/E wherein VE is an effective stop material volume assigned to a deflection mass on reaching the stop deflection by deformation of the resilient stop material and E is an impact metric relative to the kinetic energy of a deflection mass on reaching the stop deflection, and wherein the following applies for the ratio R: 0.15×10−3 m2/kg≤R≤0.6×10−3 m2/kg.

A torsional vibration damper has an input, an output and an intermediate mass arranged therebetween, a first plurality of spring elements coupled between the input and the intermediate mass that form a first stage, a second plurality of spring elements coupled between the intermediate mass and the output that form a second stage of the torsional vibration damper, at least one damper mass to damp the vibration component of the rotational movement. The first stage of the torsional vibration damper has a progressive first characteristic with at least one transition point. The second stage of the torsional vibration damper has a progressive, second characteristic with at least one transition point. All of the transition points of the first characteristic and the second characteristic are spaced apart from one another with respect to torque.

An offset in-line four cylinder engine has reduced vibration generated by a secondary inertia couple based on lateral pressures from pistons. A reference line passes through a shaft center of a crankshaft and is parallel or substantially parallel to cylinder axes of four cylinders as viewed in the axial direction of the crankshaft. As viewed in the axial direction of the crankshaft, the direction in which the reference line extends is referred to as first direction, and the direction perpendicular to the first direction is referred to as second direction. A distance between the shaft center of a first balancer shaft and the reference line as measured in the second direction is different from the distance between the shaft center of a second balancer shaft and the reference line as measured in the second direction, or a magnitude of a first unbalancing portion is different from a magnitude of the second unbalancing portion.

A spring assembly for absorbing and attenuating a torsional vibration includes an outer coil spring and an inner coil spring. The inner coil spring is disposed in an interior of the outer coil spring. The inner coil spring has a shorter free length than the outer coil spring. The inner coil spring is chamfered on end surfaces of both ends thereof. The inner coil spring has an outer diameter set to be smaller at least at an endmost winding on each of the ends thereof than at other windings thereof.