The invention relates to a torsion damping device including: a first coaxial part and a second coaxial part, springs acting circumferentially between the first coaxial part and the second coaxial part, a plurality of seats, at least one of the seats is a seat that can be mounted in a first orientation and in a second orientation, this seat being a worn seat mounted in the second orientation and exhibiting traces of wear caused by previous use in the first orientation.

A damper device including an input element and an output element; an elastic body transmitting torque between the input element and the output element; and a rotary inertia mass damper having a mass body. The rotary inertia mass damper includes a sun gear, a carrier rotatably supporting pinion gears, and a ring gear that meshes with the pinion gears and serving as the mass body. A pair of washers is located on both sides of each pinion gear axially. The ring gear includes an annulus gear having internal teeth meshing with the pinion gears and a weight body fixed to the annulus gear such that the weight body is in contact with a side surface of the annulus gear. An inner circumferential surface of the weight body is supported in a radial direction by a tip of the pinion gear or an outer circumferential surface of the washer.

A torsional-vibration-reducing-device manufacturing method includes: molding an input rotating member and an output rotating member through punching press machining and bending press machining performed on plate materials; performing heat treatment on the molded input rotating member and the molded output rotating member; and assembling a damper product that includes, as components, the input rotating member and the output rotating member on which heat treatment has been performed, and a coil spring. The molding includes drilling processing for forming a hole opened in an outer-diameter direction with respect to the center line of rotation, at a position of at least one rotating member of the input rotating member and the output rotating member, the position serving as a spring holding section for holding the coil spring. The method further include cleaning the damper product with a cleaning solution and removing the cleaning solution remaining after the cleaning.

A lock-up device includes an input-side rotary member, an output-side rotary member, an outer peripheral side torsion spring, a restriction member and a float member. The restriction member is attached to the output-side rotary member. The restriction member includes a first restriction part. The first restriction part is disposed at an interval from the output-side rotary member in an axial direction. The float member is rotatable relatively to the input-side rotary member and the output-side rotary member. An inner peripheral end of the float member is disposed between the output-side rotary member and the first restriction part in the axial direction.

A lock-up device includes an input-side rotary member, an output-side rotary member, an outer peripheral side torsion spring, a restriction member and a float member. The restriction member is attached to the output-side rotary member. The restriction member includes a first restriction part. The first restriction part is disposed at an interval from the output-side rotary member in an axial direction. The float member is rotatable relatively to the input-side rotary member and the output-side rotary member. An inner peripheral end of the float member is disposed between the output-side rotary member and the first restriction part in the axial direction.

A seat member includes a pressing part to be pressed by at least either of a first rotary member and a second rotary member. The seat member also includes a sliding part. The seat member is disposed to be changeable in posture between a first posture and a second posture, the first posture causing a radially outer part of the pressing part to be contacted to the at least either of the first rotary member and the second rotary member when an absolute value of a rotational angle of the second rotary member with respect to the first rotary member is less than a predetermined value, the second posture causing the sliding part to partially slide against the first rotary member when the absolute value of the rotational angle of the second rotary member with respect to the first rotary member is greater than or equal to the predetermined value.

A damper device includes a first rotor, a second rotor, an elastic coupling part elastically coupling the first and second rotors in a rotational direction, and a hysteresis generating mechanism. The hysteresis generating mechanism generates a hysteresis torque and includes a friction member. The friction member is configured to make frictional contact with the first or second rotor. The friction member does not make frictional contact with the first and second rotors in a first torsion angular range where torsion is caused from a neutral condition to a first side and a second side in the rotational direction. The friction member makes frictional contact with the first or second rotor so as to generate a hysteresis torque in a second torsion angular range exceeding the first torsion angular range. The friction member is set in a neutral position by actuation of the elastic coupling part in the neutral condition.

A damper device includes a first rotor, a second rotor, an elastic coupling part elastically coupling the first and second rotors in a rotational direction, and a hysteresis generating mechanism. The hysteresis generating mechanism generates a hysteresis torque and includes a friction member. The friction member is configured to make frictional contact with the first or second rotor. The friction member does not make frictional contact with the first and second rotors in a first torsion angular range where torsion is caused from a neutral condition to a first side and a second side in the rotational direction. The friction member makes frictional contact with the first or second rotor so as to generate a hysteresis torque in a second torsion angular range exceeding the first torsion angular range. The friction member is set in a neutral position by actuation of the elastic coupling part in the neutral condition.

A damper device includes a first rotor, a second rotor, an elastic coupling part having first and second elastic members, and a hysteresis generating mechanism. The hysteresis generating mechanism includes a friction member, and generates a hysteresis torque. The friction member does not make frictional contact with the first and second rotors in a first torsion angular range where the torsion is caused between the first and second rotors by a first torsion angle from a neutral condition, makes frictional contact with the first or second rotor in a second torsion angular range exceeding the first torsion angle so as to generate the hysteresis torque, and does not make frictional contact with the first and second rotors in a predetermined torsion angular range within the second torsion angular range. In the neutral condition, the friction member is set in a neutral position by actuation of the elastic coupling part.

A damper device includes a first rotor, a second rotor, an elastic coupling part having first and second elastic members, and a hysteresis generating mechanism. The hysteresis generating mechanism includes a friction member, and generates a hysteresis torque. The friction member does not make frictional contact with the first and second rotors in a first torsion angular range where the torsion is caused between the first and second rotors by a first torsion angle from a neutral condition, makes frictional contact with the first or second rotor in a second torsion angular range exceeding the first torsion angle so as to generate the hysteresis torque, and does not make frictional contact with the first and second rotors in a predetermined torsion angular range within the second torsion angular range. In the neutral condition, the friction member is set in a neutral position by actuation of the elastic coupling part.