The disclosure provides a drive device including a gear, a bearing, and a motor rotor. The gear includes an installation hole. The bearing is disposed in the installation hole of the gear and includes a rotation hole, a sliding groove, and a drive assembly. The sliding groove communicates with the rotation hole, and the drive assembly is movably disposed in the sliding groove. The motor rotor rotatably passes through the rotation hole of the bearing. The drive assembly is moved to lock the bearing by the rotation of the motor rotor, and the torsion force of the motor rotor is transmitted to the gear through the bearing.

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 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 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 isolating torque coupler includes a drive element assembled between annular cage elements of a driven element. The cage elements each include a plurality of aligned voids. The drive element includes a hub portion and a plurality of lobes with each of the lobes including a first edge and a second edge. Openings in the drive element are aligned with the voids of the cage elements to accommodate isolator springs. Each isolator spring is a helical coil compression spring having squared ends. A first edge of each of the lobes of the drive element is parallel to a second end of the corresponding one of the voids of the driven element. A second edge of each of the lobes of the drive element is non-parallel to a first end of the corresponding one of the voids of the driven element.

A turbine damper assembly, for a torque converter, includes a driven plate and an intermediate plate. The driven plate engages and drives the intermediate plate through elastic drive elements. The driven plate includes an axially extended, circumferentially oriented, driven plate flange that both centers the intermediate plate with respect to the drive plate and also assists in containing the elastic drive elements in circumferential curved cavities during and after assembly of the turbine damper assembly.

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.

A drive assembly for a vehicle drive train includes a base assembly including a base hub configured for non-rotatably connecting to an outer circumferential surface of a transmission input shaft. The base assembly includes a torsional damper fixed to the base hub. The torsional damper includes an input section and an output section drivingly connected by springs. The springs allow relative rotation between the input section and the output section. The output section of the torsional damper is non-rotatably fixed to the base hub. A hub assembly extension is configured for non-rotatably connecting to an engine crankshaft. The hub assembly extension is non-rotatably fixed to the input part of the torsional damper at an engine side of the torsional damper. The torsional damper allows relative rotation between the hub assembly extension and the base hub.

A method of assembling a damper device includes overlapping a first support portion of a first rotor and a first accommodation portion of a second rotor to eliminate an axial offset therebetween; disposing a first elastic member in the first support portion and the first accommodation portion; overlapping a second support portion of the first rotor and a second accommodation portion of the second rotor to eliminate an axial offset therebetween by simultaneously compressing the first elastic member and rotating the second rotor relative to the first rotor to a first-side in a rotational direction; disposing a second elastic member in the second support portion and the second accommodation portion; and simultaneously compressing the second elastic member and rotating the second rotor relative to the first rotor to a second-side in the rotational direction by angle corresponding to the offset between the first support portion and the first accommodation portion.

In a power transmission device, a dynamic damper is provided in a power transmission path having at least one damper disposed therein, and has an inertial rotating body that can rotate relative to a transmission rotating member forming part of the power transmission path, and a dynamic damper spring that can provide connection between the transmission rotating member and the inertial rotating body. A preset load is applied to the dynamic damper spring in a non-transmitting state of the power transmission path. The dynamic damper spring is supported on either one of the transmission rotating member and the inertial rotating body so as to apply the preset load to the dynamic damper spring in the non-transmitting state, and a gap is set in a rotational direction in the non-transmitting state between the dynamic damper spring and an other one of the transmission rotating member and the inertial rotating body.