A damper device includes a hub flange, an input rotor, an elastic member, and a contact assist mechanism. The hub flange includes internal teeth meshed with external teeth of a power transmission shaft. The input rotor is disposed to be rotatable relative to the hub flange. The elastic member elastically couples the input rotor and the hub flange. The contact assist mechanism is configured to cause contact between the internal teeth of the hub flange and the external teeth of the power transmission shaft.

A power transmission device includes a flywheel and a torque limiter unit fixed to the flywheel. The flywheel includes an annular portion and an accommodation portion provided on an inner peripheral side of the annular portion to accommodate the torque limiter unit. The torque limiter unit includes a first plate, a second plate, a friction disc disposed between the first and second plates, and a pressing member. A torque is inputted to the first plate. The first plate includes first engaging portions. The second plate is axially opposed to and non-rotatable relative to the first plate. The second plate includes second engaging portions engaged with the first engaging portions. The pressing member presses the second plate onto the friction disc. The annular portion of the flywheel is provided with recesses on the inner peripheral surface thereof. The recesses are recessed radially outward in opposed positions to the second engaging portions.

A damper device includes a first rotor, a second rotor, a plurality of elastic members and a stopper mechanism. The stopper mechanism includes a plurality of first cutouts, a plurality of second cutouts and a plurality of stop members. A pair of the first and second cutouts is provided on both circumferential sides of each of a plurality of accommodation portions of the second rotor so as to circumferentially extend therefrom. The stop members are fixed to the first rotor. Each stop member is circumferentially movable within the pair of the first and second cutouts. The second rotor includes a first protruding portion circumferentially protruding on one of a pair of pressing surfaces of each accommodation portion. Each of the first cutouts, which is a hole, extends at an end thereof located closer to each accommodation portion toward the first protruding portion.

A damper device includes a first rotor, a second rotor, a plurality of elastic members and a stopper mechanism. The stopper mechanism includes a plurality of first cutouts, a plurality of second cutouts and a plurality of stop members. A pair of the first and second cutouts is provided on both circumferential sides of each of a plurality of accommodation portions of the second rotor so as to circumferentially extend therefrom. The stop members are fixed to the first rotor. Each stop member is circumferentially movable within the pair of the first and second cutouts. The second rotor includes a first protruding portion circumferentially protruding on one of a pair of pressing surfaces of each accommodation portion. Each of the first cutouts, which is a hole, extends at an end thereof located closer to each accommodation portion toward the first protruding portion.

A damper device includes a first rotor, a second rotor, a plurality of elastic members, and a spring seat. The spring seat includes an end surface support portion and an outer periphery support portion. The end surface support portion includes a recess on a radially middle part thereof. The recess is recessed toward at least one of the elastic members. The end surface support portion supports one end surface of the at least one of the elastic members. The end surface support portion is supported by a pressing surface of a first accommodation portion of the first rotor and a pressing surface of a second accommodation portion of the second rotor. The outer periphery support portion supports part of a radially outer part of the at least one of the elastic members.

A torque converter includes a front cover arranged to receive a torque and a lock-up clutch engaged with the front cover. The torque converter further includes a damper assembly engageable with the lock-up clutch. The damper assembly includes an inner spring assembly, an outer spring assembly arranged radially outside of the inner spring assembly, and a lower cover plate supporting the inner spring assembly. The lower cover plat includes a chamfer configured to retain the outer spring assembly in a spring window.

A damper device includes first and second rotors, a first pre-damper, and a first main elastic member. The second rotor includes a hub and a flange. The first pre-damper elastically couples the hub and the flange in a rotational direction, and is actuated in a first range of torsion angle between the first and second rotors. The first main elastic member elastically couples the first and second rotors in the rotational direction, and is actuated in a greater second range of torsion angle. The first pre-damper includes first and second subordinate elastic members. The first subordinate elastic member is compressed in a neutral state, and urges the flange to a first side in the rotational direction with respect to the hub. The second subordinate elastic member is compressed in the neutral state, and urges the flange to a second side in the rotational direction with respect to the hub.

A torsional vibration damper for a drive train includes an axis of rotation, a multi-flange damper for damping torsional vibrations, a torque limiter unit for limiting a maximum transmissible torque, an outer hub connecting the multi-flange damper to the torque limiter unit for torque transmission, and an inner hub for connection to a transmission input shaft. The multi-flange damper has a plurality of flanges. The torque limiter unit is arranged radially inside the multi-flange damper and includes an inner plate and an outer plate. The outer hub is arranged radially between the multi-flange damper and the torque limiter unit and the inner hub is arranged radially inside the torque limiter unit. The outer hub includes an external toothing engaged with each of the plurality of flanges and an internal toothing engaged with the outer plate.

A torsion damper is configured to be disposed inside a coil spring. The torsion damper includes a body and a helical groove. The body is made of resin. Besides, the body has a columnar shape. The helical groove is provided on the outer peripheral surface of the body.

An isolator comprising a pulley having a pulley stop, a plate attached to the pulley, a shaft, the pulley journalled to the shaft, a torsion spring attached to the shaft, a damping member attached to the torsion spring, the damping member disposed between the plate and the pulley, and the damping member compressing a damping fluid against the pulley stop.