Abstract: A power transmitting mechanism is provided in which a driving member rotatingly transmitting power and a driven member receiving the transmitted power are arranged concentrically for rotation relative to each other. A torsion member is accommodated between the driving member and the driven member. A first hysteresis mechanism including at least one friction member is provided on the inner peripheral side of a spacing accommodating the torsion mechanism. The friction member of the first hysteresis mechanism may be split into a plurality of portions each passing through, with clearance, a respective hole or cut-out in the driven member. A second hysteresis mechanism including at least one friction member is arranged outside the space accommodating the torsion mechanism. The second hysteresis mechanism generates hysteresis separate from that generated by the first hysteresis mechanism. The torsion member may be plural torsion springs with differing spring constants.

Abstract: A friction damping device (50) capable of generating friction torque for controlling the relative rotation of a first and a second flywheel mass of the twin mass flywheel (10), the friction damping device comprising a first (62) and a second (51) friction member operatively connected with one flywheel mass (12) via a common drive formation (cdf) which forms part of the second friction member. A third friction member (56) is sandwiched between the first and second friction members and is operatively connected with the other flywheel mass (11), and actuating means (61, 67) is operative to axially displace the first and second friction members relative to each other to modify the friction generated by the device upon rotation of the third friction member relative to the first or second friction members resulting from relative rotation of the flywheel masses.