Miniaturization And Application Of Hybird Ultrasonic Motor Using Longitudinal And Torsional Vibration Modes

This important project was granted by the project of the National Natural Science Foundation ofChina （No.50735002） and Youth Science and Technology Innovation Fund （No.56V1028）.Hybrid ultrasonic motor using longitudinal-torsional vibration modes （LTUSM） has manyadvantages such as large torque/volume ratio, strong controllability, positive characteristics consistent,good stability at low speed and good performance of dynamic response which earn broad applicationprospects in devices’ drive and control technology. The working principle, the miniaturization design,experiments and an application of the stress-type LTUSM are studied in this article. The maincontributions of the dissertation were summarized as follows:The working principle of the stress-type LTUSM was studied, analysis of the piezoelectric effectof piezoelectric ceramic and its assembly method was analyzed, two kinds of miniaturization researchdirection of the motor was promoted.Based on the simulation and experimental research of support structure, processing and assemblyrequirements, the preload, longitudinal and torsional frequency consistency regulation and frictionmaterial selection of Φ10mm stress-type LTUSM, the output properties of the motor was analyzed forthe reference of miniaturization design of the motor. Several prototypes were made and the maximumtorque of them is0.12N m.A contact model of was established and the relationship between the preload and torque androtation speed and the output torque was studied. The comparison of stimulation results of the modeland the experimental results of a Φ20mm prototype of the stress-type LTUSM showed the accuracyand the prediction ability of the model.A new type of the stress-type LTUSM based on the d₃₁effect of PZT8ceramics is developed.Finite element analysis was accomplished to optimize the structure of the motor. A prototype wasmanufactured and tests on the prototype validated the feasibility of the new excitation theory.A shutter driving mechanism was designed for the intelligent sunshading system according toadvantages of the stress-type LTUSM which showed the superiority in structure driven applications.