In this study we investigate cylindrical dynamic damper to reduce electro-magnetic vibration of electric rotating machinery as turbine generator. In a turbine generator, the rotating electro-magnetic pull force of the rotor causes the stator core vibration of the oval deformation rotating synchronously with the rotation speed of the rotor. Applying a cylindrical dynamic damper to the stator core, one of the responses of the oval natural modes can be reduced, and we get the stationary deformation shape on the stator core for the electro-magnetic force. Then the transmission of the electro-magnetic vibration to the base of the generator from the stator core can be efficiently reduced by supporting the stator core at the node points of the stationary oval deformation mode. The cylindrical dynamic damper is very suitable to install in the turbine generator.
