Motor Core Iron Loss Analysis Evaluating Shrink Fitting and Stamping by Finite-Element Method

We describe a method to analyze the effects of shrink fitting and stamping on the mechanical stress distribution and iron loss in motor cores. Shrink fitting and stamping are important processes in manufacture of motor cores from electrical steel. The mechanical stress distribution is evaluated by a structural finite-element method, and the iron loss is evaluated by combined analysis of the electromagnetic field (by a finite-element method) and mechanical stress. The method clearly shows that the iron loss becomes larger as the width of the shrink fit increases, an effect borne out by experiment. In regard to the effect of stamping, calculation results again agree well with experimental data