Research On Locking Device Driven By Ultrasonic Motor For Magnetic Bearing Flywheel

With the development of the spacecraft attitude control system, the magnetic bearing flywheel asits superior control precision and long life stand out by the growing number of applications. But a gapexists between the stator and the rotor of the magnetic bearing flywheel, and the flywheel isnon-contact support. So a locking device is used to eliminate the gap in order to prevent it from shockand vibration. Since the present locking devices driven by initiating explosive device or magneticmotor have the disadvantages such as heavy weight, large size, and complex structure. Taking theadvantage of ultrasonic motors such as high torque, small size, and light weight, ultrasonic motor isconsidered as the ideal actuator. So a new kind of locking device driven by ultrasonic motor formagnetic bearing flywheel was designed and evaluated. The main research contents and results are asfollows:1. The concept of the magnetic bearing flywheel system was introduced, and research statusabout locking device for magnetic bearing flywheel was described. The classification, characteristicsand applied research of ultrasonic motor were summarized.2. The locking device driven by the ultrasonic motor was designed. The type of ultrasonic motorwas selected and the motor was improved and optimized based on aerospace applicationrequirements.3. A drive and control system of ultrasonic motor for locking device was designed. Theautomatic control including locking and unlocking of locking device was realized.4. Experiments were carried out. The key performance parameters of ultrasonic motor weretested, such as modal testing for stator， the electrical performance, and temperature risecharacteristics. The vibration environment experiment and locking effect test of locking device werecarried out. It was showed that the locking device driven by ultrasonic motor could effectivelycomplete the locking and unlocking tasks.