Optimization of the stator of a rod shape ultrasonic motor using bending modes

摘要

In order to improve the performances of the ultrasonic motor developed by authors,a finite element (FE) optimization design of the stator is developed,which is an efficient way to meet the design requirements.First,a parametrization of the stator is carried out.Then,in order to reduce the number of design variables and their variation ranges,sensitivity analysis of stator's modes is performed.The rotational speed coefficient of the motor,as one of important parameters of motor output performances,is selected as the objective functions.Zero-order optimization method is chosen as the basic tool of structural updating of the stator.The optimization results show that the rotational speed of the optimum structure is 44.8% more than that of the initial structure.Moreover,the optimization method can improve the design efficiency of the motor.A prototype motor is manufactured using the optimized results.The optimized motor,20 mm in diameter,has shown some advantages such as high rotational speed (206r/min)and large torque (0.258 N.m ).