A power tool includes a housing, an auxiliary handle, and a vibration damping assembly. The auxiliary handle includes a front end and a gripping portion. The vibration damping assembly includes a mass member and an elastic element. The auxiliary handle further includes an end cap arranged at a rear end of the gripping portion where the rear end is far away from the housing relative to a front end of the gripping portion. An accommodating cavity for accommodating the vibration damping assembly is formed around the gripping portion. The elastic element is arranged between a mass member and a cavity wall of the accommodating cavity. A ratio of a natural frequency W1 of the vibration damping assembly to a rotation frequency W2 of an output shaft in rotation is greater than or equal to 0.7 and less than or equal to 1.3.

A spring casing of a starter device of an internal combustion engine has a base body provided with a spring receptacle. A cover plate is provided to cover at least partially the spring receptacle. A connecting device is provided that connects the cover plate and the base body to each other. The connecting device secures the cover plate against a movement relative to the base body in a direction of a center axis of the spring casing. The connecting device only has a first part that is a component of the base body and a second part that is a component of the cover plate and has no further parts. A starter device with such a spring casing is provided.

A torsional vibration damper that a torsional vibration damper having a planetary gear unit, and a manufacturing method of the torsional vibration damper for limiting damages on gears of the planetary gear unit due to dimension errors. In the planetary gear unit, at least one of a sun gear, a ring gear, and a set of planetary gears is/are formed by a press forming method. The gear formed by the press forming method is engaged with the remaining gears in such a manner that a thinner portion of each tooth is individually engaged with a thicker portion of the adjacent teeth of the remaining gears.

A damper device for transmitting power to an output-side member is disclosed. The damper device includes input-side and output-side rotors, a plurality of elastic members, and a hysteresis generating mechanism. The input-side rotor, to which power is inputted, is rotatable. The output-side rotor is rotatable relative to the input-side rotor. The output-side rotor includes a hub and a plurality of flanges. The hub is coupled to the output-side member. The plurality of flanges extend radially outward from the hub. The plurality of flanges are disposed at predetermined intervals in a circumferential direction. The plurality of elastic members are disposed circumferentially between the plurality of flanges, and elastically couple the input-side rotor and the output-side rotor in the circumferential direction. The hysteresis generating mechanism is disposed axially between the input-side rotor and the plurality of flanges, and configured to generate a hysteresis torque between the input-side rotor and the output-side rotor.

A torque fluctuation inhibiting device is disclosed. The torque fluctuation inhibiting device includes an input member, an elastic member, a mass body and a centrifugal element. The input member includes a pair of input plates disposed in axial alignment. The input member is disposed to be rotatable. The elastic member is held by the pair of input plates. The mass body is disposed to be rotated with the input member and be rotatable relative to the input member. The centrifugal element is disposed to be radially movable by a centrifugal force acting thereon in rotation of the input member. The centrifugal element is disposed between the pair of input plates.

A torque fluctuation inhibiting device is disclosed. The torque fluctuation inhibiting device includes an elastic member, an input member, a mass body and a centrifugal element. The input member is a member to which a torque is inputted through the elastic member. The input member is disposed to be rotatable. The mass body is disposed to be rotated with the input member and be rotatable relative to the input member. The centrifugal element is disposed radially outside the elastic member. The centrifugal element is disposed to be radially movable by a centrifugal force acting thereon in rotation of the input member.

A torque transmission assembly including a hydrodynamic torque convener able to be coupled to a crankshaft on the one hand, and able to be coupled to a gearbox input shaft on the other, the torque converter including a primary element and a secondary element which are rotationally mobile about an axis of rotation, and damping means including a transmission member and a bearing element, the transmission member including an elastic leaf rotating as one with the primary element or with the secondary element, and the bearing element being home by the secondary element or by the primary element respectively, the elastic leaf being capable of flexing and of transmitting a rotational torque between the primary element and the secondary clement, the flexing of the elastic leaf being accompanied by a relative rotation between the primary and secondary elements.

The present damper device includes a large hysteresis mechanism, generating a large hysteresis torque, and a hysteresis inhibiting mechanism. In a positive-side torsional region, when relative rotation is performed until reaching a maximum torsion angle from a neutral position, the hysteresis inhibiting mechanism deactivates the large hysteresis mechanism until the relative rotation reaches a first torsion angle from the neutral position, but activates the large hysteresis mechanism until the relative rotation reaches the maximum torsion angle from the first torsion angle; and when the relative rotation is performed until reaching the neutral position from the maximum torsion angle, the hysteresis inhibiting mechanism deactivates the large hysteresis mechanism until the relative rotation reaches a second torsion angle less than the first torsion angle from the maximum torsion angle, but activates the large hysteresis mechanism until the relative rotation reaches the neutral position from the second torsion angle.

A decoupler assembly comprises a torque equalizer and a one-way clutch bearing. The torque equalizer comprises an inner member having a rotational axis, an outer member disposed concentrically and surrounding the inner member, and two arcuate spring elements arranged between the inner member and the outer member, and configured to transmit torque between the inner and outer members. The inner member is rotationally displaceable relative to the outer member at least 30 degrees upon compression of the two arcuate spring elements. The one-way clutch bearing is located in the same radial plane as torque equalizer and rotationally connected to the inner member or the outer member. The one-way clutch bearing comprises an outer race, an inner race, and a plurality of individual wedging locking elements that are disposed between the inner and outer races. The decoupler assembly may comprise a single spiral spring element or a rubber-based spring element.

A torsional vibration damper comprises an axially movable locking piston including a piston plate, a torque input member including a cover plate, a support plate disposed axially opposite the cover plate and a supporting member mounted to both the cover and support plates, and a unitary radially elastic output member pivotable relative to and elastically coupled to the torque input member. The output member is disposed axially between the cover plate and the piston plate. The output member includes an output hub and a curved elastic blade configured to elastically and radially engage the supporting member and to elastically bend in the radial direction upon rotation of the cover plate with respect to the output member. The cover plate at least partially covers an axially first outer surface of the output member. The support plate partially covers an axially second outer surface of the output member.