A lock-up device includes a clutch part and a damper part. The clutch part is disposed between a front cover and a turbine. The clutch part transmits or blocks torque. The damper part transmits torque from the clutch part to the turbine, and absorbs torsional vibration. The damper part includes an input member, an output member, a plurality of elastic members, and a support member. The input member is connected to the clutch part. The output member is rotatable relative to the input member and is connected to the turbine. The elastic members are accommodated in the input member, and elastically connect the input member and the output member in a rotational direction. The support member has a connecting part and a plurality of support parts. The connecting part is connected to the input member. The plurality of support parts support inner peripheral surfaces of the plurality of elastic members.

An integrated gear and torsional vibration damper assembly (10, 20, 30, 30) includes a gear (11, 21, 31, 41) having a toothed portion (11a, 21a, 31a, 41a) and a torsional vibration damper (12, 22, 32, 42) supported on the gear (11, 21, 31, 41) for limited rotational and dampened movement relative to each other. The gear (11) may include a hub portion (11b), and the torsional vibration damper (12) may be supported on the hub portion (11b) of the gear (11). Alternatively, the gear (21) may include a hub portion (21b), an intermediate ring (23) may be supported on the hub portion (21b) of the gear (21), and the torsional vibration damper (22) may be supported on the intermediate ring (23). Alternatively, the gear (31) may include a toothed portion (31a) and a hub portion (31b) that extends radially inwardly from the toothed portion (31a) and has an opening (31c) extending therethrough, and the torsional vibration damper (32) may extend through the opening (31c). Alternatively, the gear (41) may include an inner circumferential surface that engages and supports an outer circumferential surface of the torsional vibration damper (41).

A engine starting method is carried out to start an engine of a vehicle. The vehicle includes a first hub, a second hub, and a damper. The damper connects the first hub and the second hub in a power transmission path between the engine and a generator capable of power generation and powered travel. The engine starting method determines whether or not the engine needs to be started, begins to crank the engine via the generator when the engine needs to be started, performs a first ignition when torque fluctuation caused by torsion in the first hub and the second hub is in a range of being absorbable by the damper during the cranking, and suppresses engine torque generated by the first ignition below engine torque generated by second and subsequent ignitions.

A damper assembly for a torque convert includes: a first cover plate; a second cover plate; a first spring; and second spring; an intermediate flange; and a hub flange. The first cover plate is arranged to receive a torque. The second cover plate is non-rotatably connected to the first cover plate. The first cover plate and the second cover plate define a spring window. The first spring and the second spring are each disposed in the spring window and circumferentially spaced from each other. The hub flange is disposed axially between the first cover plate and the second cover plate. The hub flange is directly engaged with the first and second springs and includes a first travel stop. The intermediate flange is disposed axially between the hub flange and the first cover plate. The intermediate flange is directly engaged with the first and second springs and includes a second travel stop having a tab extending axially towards the first cover plate. The tab is engageable with the first travel stop.

Proposed is an elastic body having variable rigidity, wherein the elastic body is used in a series elastic actuator module, connects an input and an output, and has a rigidity that varies according to the applied torque. The elastic body having variable rigidity comprises: a connection part which receives torque from the input side or the output side; and a spring part connected to and receiving torque from the one selected from among the input side and the output side which is different from the connection part, wherein the spring part is formed integrally with the connection part and has a rigidity that varies as the connection part and the spring part come into contact with each other due to deformation caused by the applied torque.

A damper device includes: an input element coupled to an engine via a clutch; an intermediate element; an output element coupled to an input shaft of a transmission; a first elastic body that is disposed between the input element and the intermediate element; and a second elastic body that is disposed between the intermediate element and the output element and that acts in series with the first elastic body. When a total moment of inertia of the output element and a rotation element that rotates integrally with the output element on the engine side with respect to the input shaft is J.sub.2, and a total moment of inertia of all rotation members included between the input shaft and a differential gear coupled to an output shaft of the transmission is J.sub.TM, 0.12≤J.sub.2/(J.sub.2+J.sub.TM)≤0.5 is satisfied.

A shock-absorbing twisting structure includes a first seat and a second seat. The first seat includes an elastic member. A stop member is arranged at one side of the first seat. The second seat is formed with a receiving chamber that is fit over the first seat, such that the elastic member is set in elastic engagement with and is supported between the first seat and the second seat. A main axle penetrates through the second seat and is received in the first seat to set the second seat in a rotatable condition. An elastic unit is arranged at each of two sides of the receiving chamber and the stop member.

Proposed is an elastic body having variable rigidity, wherein the elastic body is used in a series elastic actuator module, connects an input and an output, and has a rigidity that varies according to the applied torque. The elastic body having variable rigidity comprises: a connection part which receives torque from the input side or the output side; and a spring part connected to and receiving torque from the one selected from among the input side and the output side which is different from the connection part, wherein the spring part is formed integrally with the connection part and has a rigidity that varies as the connection part and the spring part come into contact with each other due to deformation caused by the applied torque.

A damper device includes a first rotor, a second rotor, a plurality of elastic members and a stopper mechanism. The stopper mechanism includes a first stopper hole, a second stopper hole and a plurality of stop members. The first and second stopper holes are provided on both circumferential sides of each of a plurality of first window holes of the second rotor so as to circumferentially extend therefrom. One or both of the first and second stopper holes communicates at one end thereof with each first window hole and extends at the other end thereof to a position radially outside one of a plurality of second window holes of the second rotor. The stop members are fixed to the first rotor. Each stop member axially penetrates each of the first and second stopper holes and is circumferentially movable within each of the first and second stopper holes.

A power transmission device includes a flywheel and a damper device. The flywheel includes a plurality of fixation holes. The damper device includes an input rotary member, an output rotary member, and a pair of first elastic members. The input rotary member and output rotary member each include a plurality of assembling holes disposed in corresponding positions to the plurality of fixation holes of the flywheel. The plurality of assembling holes are arranged in a circumferential direction such that two pairs of the assembling holes, each pair including two adjacent assembling holes, are each disposed at a larger interval than remaining assembling holes to produce a pair of accommodation spaces. A pair of first accommodation portions, accommodating the pair of first elastic members, is disposed radially outside the pair of accommodation spaces.