Research And Design Optimization On Disk Bearingless PM Motor

A new type of bearing-less disc PM motor is investigated. The motor consists of two functions, one part is a general short-span structure permanent motor and the other is the so-called hybrid type active magnetic bearing. The motor realizes the radial suspension by one permanent magnet biased radial bearings, and realizes the suspension of the other 3 freedom degrees by reluctance force.The function theory of the motor is introduced in this text. The motor's control independence of rotation and levitation is analysed. The mathematical model for the radial force is worked out. To improve the capability of the bearing-less slice permanent motor, to reduce the ullage of the motor and the badly additive torque, I design optimization the structure of the rotor PM, and two projects are proposed. One is four pieces rotor PM which is the same magnetized and the other is eight pieces rotor PM which is different magnetized direction. To improve the capability of the electric system, a three-level PWM power amplifier and Backboard of the control-box is designed, which are applicable to the bearing-less slice PM motor. Finally, a disc motor is designed and fabricated,and the static levitation of the rotor is successfully performed.