The Structure Design Of Miniature Linear Ultrasonic Motor

With the progress and development of science and technology, the miniaturization and integration of linear ultrasonic motor(LUSM) has become an important development direction of this domain. The research on patch type micro LUSM accordingly has been gained comprehensive attention among LUSMs. However, the patch type micro LUSM has almost no practical application at home, since some crucial performance parameters including the stability, output force and displacement resolution fail to meet the use requirements.Based on the U-shape patch type LUSM, a V-shape patch type LUSM is designed considering the structural design of the stator and the way of applying the preload. In this paper, the influences of the structure parameters of the stator on the mode consistency and the output performances of the motor are studied. The main contributions of this article are summarized as follows:1) The influence of different stator structures on the mode consistency of the stator is analyzed by using the finite element software Ansys Workbench15.0, and three V-shape patch type LUSMs with different angles of 45 degrees, 60 degrees and 90 degrees are fabricated. The experimental results show that the motor with V-shape stator has both better thrust and speed comparing with the motor with U-shape stator. Furthermore, the overall performance of the motor is the best when the angle of V-shape stator is 90 degrees. When the input voltage is 350 Vpp and the preload is 50 N;The maximal thrust of the motor can reach to 16 N and the maximal output speed can reach to 1.759m/s when the input voltage is 350 Vpp and the preload is 20 N.2) A mechanical model of the stator with hinged type beam clamping structure is established to analyze the influence of the preload spring stiffness on the performance of the motor, and the results are validated by experiments.3) Two symmetric arc-type clamps with different tangential stiffness are designed for V-shape motor with angle of 90 degrees, and the corresponding experimental investigations are carried out. The results indicate that the stability of the motor with symmetric flexible arc-type clamp has been improved dramatically comparing with the motor with asymmetric hinged type beam clam, though the output force of the latter is larger than that of the former.