Torsional oscillation damper

Abstract From the Canadian patent

A pair of concentric, rotatable shaft members which are assembled together in a shrink fit relationship. When one of the shafts is subjected to torsional oscillations, the other twists therewith until the frictional forces therebetween which cause simultaneousjrotation of both rotatable shafts is overcome by elastic torque accumulated in the other shaft causing relative motion between the two shafts and resulting in energy being dissipated by dynamic fiction thus limiting the amplitude of the torsional oscillations. To prevent fretting between the adjacent slippable surfaces, one on each shaft, a coating of nonfretting material is disposed on at least one of the two slippable surfaces, A …