Research On The New Rod-type Ultrasonic Motor Optimization Design

In view of the efficiency improvement of ultrasonic motors, the paper proposed a new type of rod-type bending traveling wave ultrasonic motor driven at the midpoint of the stator. Based on reducing the energy loss in rod-type ultrasonic motors, a new design of rod-type ultrasonic motor is scheduled. Firstly, by method of FEM software HyperWorks, the topology optimization design is researched based on the dynamic response of the stator and a preliminary conceptual topological shape of the stator is obtained. Then, based on the topological shape obtained, using the FEM software ANSYS a parametric stator is modeled and optimized. The results show the amplitude of the driving point on the stator is increased greatly and the efficiency of the new type motor is expected to improve to a certain extend.In this paper, a mathematic model of rod-type bending ultrasonic motors is built to deeply research the elliptical motion of the particle on the stator. The fact that there is no linear slip on the midpoint of the cylindrical stator is found based on decomposing the ellipse motion to the effective ellipse motion and the linear slip. Based on frequency response the topology optimization design of the stator is analyzed by the HyperWorks to reach an optimized geometric shape of the stator. The result of frequency response analyses to the optimized shape indicates that the amplitude of the midpoint on the stator multiplies. Using ANSYS, the harmonic analyse of the stator is done to research the relationship between the dimensions and the amplitude on the midpoint of the stator. A group of detail dimensions of the stator is optimized to increase the amplitude on midpoint, meanwhile, the amplitude at the endpoint of the stator decrease relatively. Finally, a mechanical structural of the stator of a rod-type ultrasonic motor driven by midpoint of the cylindrical stator is designed.