Torque limiter and power transmission device

A torque limiter fixed to a flywheel including an annular portion to which a plurality of knock pins each including a trunk portion are fixed and an accommodation portion provided on an inner peripheral side of the annular portion, the torque limiter disposed in an interior of the accommodation portion except for a part thereof fixed to the flywheel, the torque limiter comprising:

• a first plate to which a torque is inputted from the flywheel;
• a second plate axially opposed to the first plate;
• a friction disc disposed between the first plate and the second plate;
• a pressing member configured to press the second plate onto the friction disc;
• and
• a third plate configured to interpose and hold the pressing member together with the second plate therebetween, the third plate provided with a plurality of knock pin through holes in an outer peripheral part thereof such that the plurality of knock pins are fitted therein at the trunk portions thereof, the outer peripheral part attached at an attachment surface thereof to the annular portion of the flywheel, wherein
• a length between a surface of the pressing member and the attachment surface of the third plate is shorter than a length of the trunk portion of each of the plurality of knock pins, the surface of the pressing member facing the interior of the accommodation portion,
• the annular portion of the flywheel includes a plurality of attachment portions circumferentially aligned, each of the plurality of attachment portions including a protruding portion protruding radially inward,
• the third plate includes
• a support portion configured to support the pressing member,
• a tubular portion provided in an outer peripheral part of the support portion, the tubular portion covering an outer peripheral surface of the friction disc, the tubular portion axially extending and opposed to an inner peripheral surface of the annular portion of the flywheel, and
• a fixation portion provided with the plurality of knock pin through holes, the fixation portion fixed to the flywheel, and
• the tubular portion includes a plurality of openings circumferentially aligned, each of the plurality of openings disposed in a corresponding position to the protruding portion so as to avoid interference between the third plate and the protruding portion.