Abstract: A twin mass flywheel which has an input flywheel mass (11) arranged to be coupled to an engine, an output flywheel mass (12) arranged to be coupled to a drive-line, a main rolling bearing (14) for mounting the flywheel masses for relative rotation and having inner (14B) and outer (14A) race members with rolling bearing elements therebetween, and a torsional vibration damping means (17) acting between the masses to oppose relative rotation. At least one of the bearing races is located axially relative to one of the flywheel masses by an annular retaining member (25, 29) which is secured to said one flywheel mass and engages a circumferential groove (26, 30) in the bearing race. Other bearing retaining arrangements are disclosed including the use of tapering races.

Abstract: A twin mass flywheel (10) in which first (11) and second (12) flywheel masses can rotate relative to each other about an axis (C) under the control of one or more connection means (50, 31, 41) whose center of gravity moves radially with respect to the rotation axis as the flywheel masses rotate relative to each other. The centripetal loads acting on the connection means (50, 31, 41) as the twin mass flywheel rotates, tend to bias the first and second flywheel masses towards a pre-determined relative rotational position to provide speed sensitive damping of the relative rotation. The connection means may take the form of a mass (50) which moves along a first track (31) associated with the first flywheel mass (11) and a torque transmitting connection acting between the mass (50) and the second flywheel mass (12) in the form of a second track (41) also followed by the mass (50). Numerous other forms of connection means are also disclosed some of which us links (570) in place of one of the tracks.

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.

Abstract: A twin mass flywheel (10) having a friction damper (50) and a friction plate (55) with a shaped radially outer (55a) or radially inner first periphery which cooperates with a similarly shaped first periphery of a further component (54) of the damper to transfer torque between the friction plate (55) and the further component, the first periphery of the friction plate comprising a plurality of drive surfaces (55B), at least one of which is substantially tangential or chordal to the friction plate (55). The friction plate (55) may additionally have a second periphery with second drive surfaces tangential or chordal to the friction plate or it may additionally have drive formations formed as axially projecting lugs on an axially orientated surface of the friction plate. The friction plate (55) may be manufactured by sintering techniques or may have a sintered coating applied to its friction surface.

Abstract: A twin mass flywheel (10) in which two co-axially arranged flywheel masses (11,12) are mounted for limited angular rotation relative to each other and a plurality of pivotal linkages (40) interconnect the two flywheel masses. Each linkage comprises a first link (41) pivotally connected (43) to one (12) of the flywheel masses, a second link (42) pivotally connected (44) to the other (11) of the flywheel masses, and a pivot (45) for pivotally connecting the first and second links. A resilient member in the form of an elastomeric torsion unit (46) or spring (36) is associated with the pivotal connection (44) of at least one link (42) with its associated flywheel (11) for controlling the relative rotation of said flywheel masses (11, 12).