Abstract: A torsional vibration damping assembly, comprising a rotating driving disk and a driven disk having a jacket surface with a polygonal cross-section. The driven disk is arranged coaxially with the driving disk and rotates in the same direction as the driving disk. The driving disk has an overlapping ring-shaped portion that partly grips over the driven disk. A plurality of radial pockets having wedge-shaped ends are disposed around the circumference of the inside face of the ring-shaped portion of the rotating driving disk. A pair of wedge-shaped thrust pistons are arranged in each of the radial pockets. The pistons are slightly curved or planar on their sides facing the jacket surface of the driven disk. There is at least one pressure spring arranged in each pocket that keeps the pistons apart from one another. There is also a plurality of devices such as pressure springs for effecting a reset moment from the driving disk to the driven disk during idle run, that exerts almost no frictional force.

Abstract: A torsional oscillation damper includes a primary part resiliently secured via tangential compression springs to a secondary part mounted on a driven member. Provided between the primary part and the secondary part is a friction unit which is so acted upon by a rotating actuator that the value of friction decreases with increasing speed.