A high-speed hysteresis motor spindle for machining applications

Abstract

An analysis of suitable drive technologies for use in a new high-speed machining spindle was performed to determine critical research areas. The focus is on a hysteresis motor topology using a solid, inherently-balanced D2 steel shaft. An analytical model of the motor is devised in order to make performance predictions and optimization, and an experimental apparatus is constructed in order to verify the predictions of the model and investigate speed limits. The model's limitations due to a still-incomplete understanding of the vector hysteresis properties of magnetic steels are noted, and a proposal for an experiment to resolve this limitation is presented. The model predicts that the motor performance is optimized for a very thin ring of hysteretic steel. The experimental apparatus used a solid rotor. It was run up to a speed of 11,000 RPM and torque-speed curves with various drive parameters are measured.