ABOUT THE DESIGN OF VERY HIGH-FREQUENCY INDUCTION-MOTORS FOR SPINDLE APPLICATIONS

In the paper the authors deal with induction motors used in electrical spindles and fed by high frequency inverters. The design problems of high frequency machines are analyzed by the electromagnetic, the mecha nical and the thermal points of view. The possibility to use the class ical relations adopted to calculate the equivalent circuit parameters for standard motors at 50 Hz is carried out and the results are compar ed with the experimental ones. A brief overview of problems related to the mechanical design (bearings, lubrication, shaft stiffness) and to the thermal design is reported. Finally, starting from both the simul ation and the experimental results, some specific criteria for the ele ctromagnetic design are well focused.