This article presents some case studies relating to the dynamics of the large machines on spring isolated foundations. The studies comprise both vibration calculations and measurements also introducing the accuracy of numerical methods available in practical engineering. A summary of the pros and cons of spring isolated foundations in power plants is included. The cases described are from the lately built power plants of the IVO-group. The auxiliary feed water pump analysed consists of an electric motor (7 MW), a gear and two pumps. During the trial runs, severe vibrations were observed calling for thorough vibration measurements. The modelling of the whole vibrating entity in the rotating machinery, including the shaft train, oil films of bearings and the foundation is demonstrated by a turbine generator set of 100 MW. Finally, some results of a test comparing the acoustic emission and traditional vibration measurements for recognizing the rub between the shaft and the hydrodynamic bearing are presented. (orig.) 6 refs.
Puttonen, J. Luukkanen, P.  
- IVO Power Engineering Ltd., Vantaa (Finland)
- Imatran Voima Oy, Vantaa (Finland)