US Patent 8376868 Rotation shaft vibration damping mechanism

A vibration damping mechanism of a rotation shaft that is not likely to be subject to the limitation in layout and that is capable of stably maintaining damping properties by a frictional contact portion without variation for a long term is provided. The vibration damping mechanism includes a shaft for outputting torque inputted from its input side end portion to its output side end portion, and a damping member having a fixed portion fixed to the shaft and a frictional contact portion held in frictional contact with the shaft, in which the frictional contact portion is provided with a clamping band for urging the frictional contact portion toward the shaft to be held in frictional contact with the shaft at a predetermined contact pressure.