Moving Analysised On Piezoelectric Coupling Of The Ultrasonicmotor Stator

Ultrasonic motor (RTWUSM) is a new-type motor, which uses the converse piezoelectriceffect of piezoelectric ceramic excited by ultrasonic vibration, using elastomer resonanceamplification, through a friction coupling to generate rotating movements or linear motion. Itsdistinguishing feature including low speed, high torque, electromagnetic compatibility, goodpower, and self-locking function etc. It has a broad application in the micro-Electromechanicalsystems, aerospace and medical field, which was sensitive at magnetic or the field withrequirements of high positioning accuracy.Based on the finite element analysis and structure characteristic of small wave-typeultrasonic motor stator, studied the structural vibration mode, structural optimization design andthe particle motion of the stator. The main works are evidenced as follows:1. A summarize introduction of some basic content to the study, including piezoelectriceffect, material parameter of piezoelectric ceramic, wave-type ultrasonic motor structure, statorstructure, and vibration frequency of the stator.2. Introduced the question needed attention when using ANSYS at the analysis ofpiezoelectric coupling, and verified the analysis method is useful by the coupled analysis ofpiezoelectric bimorph. Studied the mechanics of travelling wave and the characteristic of statorsurface wave. By changing the structure of the bimorph and applying couple sine voltage to thebimorph, gained the travelling wave motion.3. Taking RTWUSM60 as an example, stator model including no-tooth stator model andstator with tooth structure model. The stator surface partical moving track equation for eachmodel was given in the theory. FEM models were built and modal analysis, harmonic responseanalysis and transient analysis were used in this paper. The best vibration mode of stator can be obtained by modal analysis; the amplitude-frequency curves of surface partical was found byharmonic response analysis, and using transient analysis, the stator surface partical moving trackcan be obtained. The stator tooth with amplitude amplification effect and surface partical movingtrack was ellipse can be proved by analysis results.4. The stator is composed of piezoelectric ceramic, bonding layer and elasto metal body, thestructural vibration mode was sensitive to the structure of stator. Through changing the structureparameters of RTWUSM50 stator, the best vibration mode and working frequency were obtainedand structural optimization design was done. Model was built based on optimization parameters,the changing law of surface partical amplitude in the radial direction was studied. At last, theinfluence of piezoelectric materials and stator tooth structure to the amplitude of surface partical...