Torque fluctuation absorber

A torque fluctuation absorber comprising:

• a disc fixed to a flywheel to which a driving force is transmitted from a drive source;
• a hub arranged on a radially inner side of the disc and fixed to an input shaft of a transmission;
• first and second side plates fixed to the disc so as to sandwich the disc;
• a damper member accommodated in window portions of the first and second side plates and cut portions of the hub and absorbing torque fluctuations transmitted from the side plates to the hub;
• first and second control plates provided at axial both sides of the hub and arranged between the first and second side plates respectively, the first and second control plates being riveted by a stopper pin;
• a first hysteresis mechanism axially arranged between the first control plate and the hub and between the second control plate and the hub and including first and second low friction members, the first hysteresis mechanism generating a small hysteresis by biasing the first and second low friction members towards one of the control plates and the hub;
• a second hysteresis mechanism axially arranged between the first control plate and the first side plate and between the second control plate and the second side plate and including first and second high friction members, the second hysteresis mechanism generating a large hysteresis greater than the hysteresis generated by the first hysteresis mechanism by biasing the first and second high friction members towards one of the side plates and the control plates;
• and
• the hub including a flange portion having a through-hole into which the stopper pin is inserted, a relative rotational angle between the control plates and the hub being defined by a clearance formed between the through-hole and the hub in a relative rotational direction of the hub and the control plates, the first hysteresis mechanism being activated when the relative rotational angle is defined within the clearance.