弯扭复合模态超声电机设计与实验研究

发布时间：2018-08-05 18:10

【摘要】：超声波电机是一种典型的振动学、材料学、物理学等多个学科综合的超声驱动设备，其高精度、快速响应等优点使其在很多领域有较好的应用价值。目前我国的超声波电机普遍存在输出效率较低、扭矩较小，寿命短等问题，还没能够实现产业化。夹心式复合型驻波超声电机多用于实现直线运动，因其结构灵活、输出力矩大、速度高等特点，是近年来超声电机领域的研究热点。复合型驻波超声电机多利用压电陶瓷的d33模式或d15模式，要求压电陶瓷具有尽量高的压电常数和机电耦合系数，，高机械品质因数Qm和低介质损耗因数tan等特点。切向极化的扭振压电陶瓷，采用平面切变d15模式，具有压电应变常数较大，机电耦合系数k15较高等诸多优点，直接用于驱动，输出能力更优，较适合在驻波型直线超声电机中应用。然而其在超声电机中应用研究还相对较少，尤其是对于弯振模态和扭振模态复合型的超声电机还很少见，因此本文提出了一种弯振模态和扭振模态复合型的超声电机新构型。弯振模态采用厚度伸缩的d33模式用于提供正压力，扭振模态采用平面切变的d15模式，直接用于驱动，使得电机在驱动效率和驱动输出能力上具有很大的优势。首先对弯扭复合模态超声电机构型进行设计，对压电陶瓷的极化和安装布置进行研究，对弯扭复合型超声电机的椭圆轨迹形成和驱动机理进行分析。对电机各部分的选材以及等效电路模型进行了研究，导出扭振共振频率方程，然后以此为基础，建立电机的有限元模型，选择电机合适的振型模态，通过变幅杆加等截面驱动足的设计方法实现弯扭模态的频率简并，通过瞬态分析对定子驱动端的振动轨迹进行分析。最后进行弯扭复合模态超声电机实验样机的研制，并进行性能测试，电机空载最大输出速度为380mm/s，最大推力为13N。
[Abstract]:Ultrasonic motor (USM) is a typical ultrasonic driving device in many fields, such as vibration, materials, physics and so on. It has the advantages of high precision and fast response, so it has good application value in many fields. At present, the ultrasonic motor in our country has many problems, such as low output efficiency, low torque, short life and so on. Sandwich composite standing wave ultrasonic motor is widely used to realize linear motion. Because of its flexible structure, large output torque and high speed, it is a hot research topic in the field of ultrasonic motor in recent years. The composite standing wave ultrasonic motor usually uses the d33 mode or d15 mode of piezoelectric ceramics, which requires piezoelectric ceramics to have as high piezoelectric constant and electromechanical coupling coefficient as possible, high mechanical quality factor QM and low dielectric loss factor (tan). Torsional piezoelectric ceramics with tangential polarization, which adopt plane shear d15 mode, have many advantages, such as high piezoelectric strain constant, high electromechanical coupling coefficient k15, and so on. It is suitable for application in standing wave linear ultrasonic motor. However, the research of its application in ultrasonic motor is relatively few, especially for ultrasonic motor with combined mode of bending vibration and torsional vibration. Therefore, a new configuration of ultrasonic motor with combined mode of bending and torsional vibration is proposed in this paper. The bending mode is used to provide the positive pressure with the thickness expansion of D33 mode, and the torsional vibration mode is the plane shear d15 mode, which is directly used to drive the motor, which makes the motor have a great advantage in driving efficiency and driving output ability. Firstly, the configuration of bending-torsional composite mode ultrasonic motor is designed, the polarization and installation of piezoelectric ceramics are studied, and the ellipse track formation and driving mechanism of bending-torsion composite ultrasonic motor are analyzed. The material selection and equivalent circuit model of each part of the motor are studied, and the resonance frequency equation of torsional vibration is derived. Based on this, the finite element model of the motor is established, and the suitable mode of the motor is selected. The frequency degeneracy of the bending and torsional modes is realized by the design method of variable amplitude bar with constant cross section driving foot, and the vibration trajectory of the stator driving end is analyzed by transient analysis. Finally, the experimental prototype of bending-torsional mode ultrasonic motor is developed, and its performance is tested. The maximum output speed of the motor is 380 mm / s and the maximum thrust is 13 N.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM302

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