A disk-type elastic coupling usable in a multi-mass flywheel in the drive train of a motor vehicle with an internal combustion engine, wherein:
- (a) a first elastic coupling half constitutes a first mass and has at least two mutually opposing side disks which have a common axis defining an axial direction, and which form a liquid-tight inner space which can be filled with a damping fluid;
- (b) within the inner space is a second mass which is guided against axial displacement by the side disks and is connected to the first mass via first elastic means;
- (c) within the inner space is a third mass representing a second elastic coupling half and being connected to the second mass via second elastic means;
- (d) the three masses are connected in series in the direction of transmission of the engine force via the first and second elastic means and are turnable to a limited extent with respect to each other;
- (e) at least one damping means for damping relative movement of said first and second masses comprises a plurality of fluid displacement chambers for said damping fluid which are arranged circumferentially in said inner space and said damping means is connected in parallel with the first elastic means;
- (f) the second mass has projections fixed thereon for rotation with it, each of them extending into one of the fluid displacement chambers;
- (g) said first elastic means comprises a plurality of elastic elements and each two adjacent projections form a pair of projections and enclose between them one of the elastic elements;
- (h) each two adjacent displacement chambers enclose between them a spring chamber;
- (i) each spring chamber has a greater inside diameter than the two adjoining displacement chambers in order to form an axial shoulder at each end of said spring chamber;
- (j) each elastic element is retained in its respective spring chamber by a pair of spring plates which rest against the axial shoulders so as to be movable into the spring chamber by respective adjacent projections, whereby said elastic elements retained between said spring plates are compressed by relative rotation of said first and second masses in a first direction;
- and said projections and fluid displacement chambers provide damping of relative rotation of said first and second masses in a second direction opposite said first direction;
- and
- (k) an additional damping means comprises an additional fluid displacement chamber, said additional fluid displacement chamber being at least partially defined by friction means comprising a pair of friction jaws secured to said first means, and means for applying an axial force to the two friction jaws within the additional fluid displacement chamber, which force presses said jaws against axial side surface of an additional projection on the outer region of the second mass for generating a frictional damping force.