Considerations in the choice of main dimensions of stators of electrical machines in relation to their vibration characteristics

The manner in which the values of the various resonance frequencies of stators vary with changes in the length of stator-core, core thickness, frame thickness and frame material is investigated in this paper. The encased construction of stators, which is commonly used these days, is adopted for carrying out the investigations. The present study is of a general nature and is applicable to small and medium machines as well as to large machines. The investigations are not confined to the lowest resonance frequency associated with a given mode, but all the other important resonance frequencies associated with that mode are considered. In the course of the study, an attempt is made to give physical interpretation of the results.