A torque limiter, fixed to a flywheel including an annular portion to which knock pins each including a trunk portion are fixed, is disclosed. The torque limiter includes a first plate, a second plate axially opposed to the first plate, a friction disc disposed between the first and second plates, a pressing member, and a third plate. The pressing member presses the second plate onto the friction disc. The third plate holds the pressing member together with the second plate therebetween. The third plate includes knock pin through holes such that the knock pin are fitted therein. The third plate is attached at an attachment surface thereof to the flywheel. A length between a surface of the pressing member, facing an interior of an accommodation portion of the flywheel, and the attachment surface of the third plate is shorter than a length of the trunk portion of each knock pin.

A torque limiter fixed to a flywheel including an annular portion and an accommodation portion is disclosed. The torque limiter includes a first plate, a second plate axially opposed to the first plate, a friction disc disposed between the first and second plates, a pressing member, and a third plate. A torque is inputted to the first plate. The pressing member presses the second plate onto the friction disc. The third plate supports the pressing member with the second plate therebetween while the pressing member is compressed. The third plate includes a support portion supporting the pressing member and a tubular portion provided in an outer peripheral part of the support portion. The tubular portion covers an outer peripheral surface of the friction disc. The tubular portion axially extends and is opposed to an inner peripheral surface of the annular portion of the flywheel, and includes first openings circumferentially aligned.

A torsional vibration reduction apparatus has coil springs. The coil springs are received in paired input member side coil spring receiving portions and an output member side coil spring receiving portion. The paired input member side coil spring receiving portions comprise forward rotation side and reverse rotation side guide portions between forward rotation side and reverse rotation side spring pedestals. The output member side coil spring receiving portion comprises forward rotation side and reverse rotation side guide portions between forward rotation side and reverse rotation side spring pedestals. In forward rotation and reverse rotation, since the displacement of the coil springs under the centrifugal force is received by the guide portions and the vertical component force of the elastic force is small, sliding resistance is suppressed, the hysteresis torque is reduced, additive components are not required, and the installation positions of the coil springs cannot be restricted.

A torque limiter fixed to a flywheel including an annular portion and an accommodation portion is disclosed. The torque limiter includes a first plate, a second plate axially opposed to the first plate, a friction disc disposed between the first and second plates, a pressing member, and a third plate. A torque is inputted to the first plate. The pressing member presses the second plate onto the friction disc. The third plate supports the pressing member with the second plate therebetween while the pressing member is compressed. The third plate includes a support portion supporting the pressing member and a tubular portion provided in an outer peripheral part of the support portion. The tubular portion covers an outer peripheral surface of the friction disc. The tubular portion axially extends and is opposed to an inner peripheral surface of the annular portion of the flywheel, and includes first openings circumferentially aligned.

A torque limiter, fixed to a flywheel including an annular portion to which knock pins each including a trunk portion are fixed, is disclosed. The torque limiter includes a first plate, a second plate axially opposed to the first plate, a friction disc disposed between the first and second plates, a pressing member, and a third plate. The pressing member presses the second plate onto the friction disc. The third plate holds the pressing member together with the second plate therebetween. The third plate includes knock pin through holes such that the knock pin are fitted therein. The third plate is attached at an attachment surface thereof to the flywheel. A length between a surface of the pressing member, facing an interior of an accommodation portion of the flywheel, and the attachment surface of the third plate is shorter than a length of the trunk portion of each knock pin.

The present invention relates to a torsional vibration reduction apparatus which uses coil springs and can obtain expected torsional vibration reduction performance by reducing the hysteresis torque caused by the sliding of coil springs (50) without restricting the layout and requiring the additive components. The coil springs (50) are received in paired input member side coil spring receiving portions (44) and an output member side coil spring receiving portion (48). The paired input member side coil spring receiving portions (44) comprise forward rotation side and reverse rotation side guide portions (44-1a) and (44-1b) between forward rotation side and reverse rotation side spring pedestals (44a) and (44b). The output member side coil spring receiving portion (48) comprises forward rotation side and reverse rotation side guide portions (48-1a) and (48-1b) between forward rotation side and reverse rotation side spring pedestals (48a) and (48b). In both the forward rotation and the reverse rotation, since the displacement of the coil springs (50) under the centrifugal force is received by the guide portions (44-1a), (48-1b); and (44-1b), (48-1a) and the vertical component force of the elastic force is small, the sliding resistance is suppressed, the hysteresis torque is reduced, the additive components is not required, and the installation positions of the coil springs (50) cannot be restricted.