Development of the Basic Dynamical Model of a Squirrel Cage Motor

This paper deals with the basic dynamical model of electromotor whose creation was motivated by problems of electromotor vibrations and its subsequent fatigue. The model is characterized by a flexible shaft with mounted packet of sheet metals that are equipped with parallel copper bars connected by end shortcircuit rings. Finite element analysis is used for the discretization of the shaft, while the sheet metal packet of cylindrical shape is modelled as a set of rigid bodies joined using chosen viscoelastic forces and torques. The shortcircuit rings are supposed to be rigid in this basic dynamical model and the pieces of copper bars are substituted by massless springs of calculated properties. Problematic model parameters are identified by means of performed experimental modal analysis.