Design Aspects of Bearingless Torque Motors

In this paper novel topologies of multiphase bearingless motors featuring outstanding motor effciency and high radial force capacity are presented. For a systematic layout a simple design guideline is provided. These motors are especially suitable for applications where high torque at relatively low speed is demanded, therefore this configuration is referred to as bearingless torque motor. Since there are no dedicated bearing and motor windings the winding scheme becomes very simple and is furthermore characterized by concentrated coils only. Motor designs with different pole and slot configurations are compared by means of appropriate performance indexes. For the most promising design a demonstrator was manufactured and tested.