中文摘要：

研制了一种新型螺纹式空心超声电机,用于驱动光阑并控制和调节光束.由于光阑仅需有限角度转动,故采取螺纹方式连接超声电机定子和转子来施加轴向预压力和实现转子周向运动的耦合.电机仅由转子、定子和底座组成;其中转子与光阑定圈固定,实现了与光阑的一体化设计.运用有限元软件对定子进行了模态分析,选定工作频率为38.26kHz.受可加工螺纹螺距尺寸的限制,电机轴向运动使电机预压力变化较大,电机转动角度小,不能驱动光阑完成闭合或开启,故对转子进行了柔性化设计.仿真实验表明,在转动90°范围内,定、转子预压力变化在27％之内.试验研究表明：设计的电机定子振动特性良好,干扰模态距工作模态5 kHz以上;阻抗值变化不超过10％.得到的结果验证了预压力变化对电机影响小;电机驱动光阑开启时间为5 s,闭合时间为4.4s,开启、闭合直径与电机运行时间呈线性关系.该空心电机满足了光阑调节需求,具有结构简单、零部件少等特点.

英文摘要：

A new type of hollow ultrasonic motor connected by a screw was proposed to drive an aperture and control and adjust the intensity of the beam.According to the characteristics of a limited angle of rotation for the aperture,the screw was used to connect the stator and the rotor of the ultrasonic motor to apply a pre-pressure to the axial and to implement the circumferential movement of the coupling.The motor is consist of a rotor,a stator and a base and the rotor and aperture were fixed in a setting ring,by which the diaphragm integrated design was realized.The stator modal was analyzed at an operating frequency of 38.26 kHz by using the finite element software.As motor pre-axial movement brings greater pressure changes,the motor has a smaller rotory angle and can not drive the aperture to open or close.To overcome the pre-pressure changes,flexible design of the rotor was performed.Simulation results show that,at default rotation 90 ° range,pre-pressure changers are within 27％ of the variation.Tests show that the stator has excellent vibration characteristics,and its interference from work modal is 5 kHz or more; the impedance variation is not more than 10％,and the pressure change has a little effect on the motor.Furthermore,opening time of the aperture is 5 s,and its dosing time is 4.4 s.The diameter of the aperture shows a linear relationship with motor run time.The motor meets the demands of aperture adjustment,and is charaterized by simpler structure and a few aparts.