It is the purpose of this paper to make clear the effect of typical torsional viscous-friction damper on the reduction of the axial, torsional and two directions of lateral vibrations from the analytical and experimental points of view.
At first, a typical type of the torsional viscous-friction damper is fitted to a high-speed diesel engine and the axial, torsional and two directions of lateral vibration displacements at the pulley end are measured in order to investigate the effect of the damper on the reduction of these vibrations in the three dimensional space of the engine shaftings from the experimental point of view.
Next, the characteristics of the axial, torsional and two directions of lateral vibrations of the engine shaftings are investigated by three dimensional analysis of forced vibration by the transfer matrix method, which has been developed by the authors. In the vibration model, the viscous medium part is replaced with a three dimensional model in consideration of the axial, torsional and two directions of lateral vibrations. This method enables the amplitude and phase per order of all the vibrations to be analyzed.
Finally, the effect of the typical torsional viscous-friction damper on the reduction of the vibrations in the three dimensional space is evaluated by comparing the experimental results with the calculated ones. It has been shown that the typical torsional viscous-friction damper has a great effect on the reduction of not only torsional vibration but also axial and two directions of lateral vibrations coupled with torsional vibration. But the reduction effect on the coupled axial vibration is not so much as on the coupled lateral vibrations. Also, it has been clarified that the damper has little effect on the reduction of the uncoupled axial vibration due to its structure.