微型化矩形振子近似行波型直线超声波电动机

摘要

With the aim of realizing quasi-traveling wave drive in ultrasonic linear micromotor, a novel quasi-traveling wave ultrasonic linear motor using a ring type rectangular vibrator with the size of 39 mmx6 mmxl2. 7 mm was proposed. Combined with the finite element modal analysis, the motor operating principle was described, that the traveling wave was excited and propagated along the ring type rectangular vibrator depending on the superposition of two orthogonal flexural-vi-bration modes with a spatial phase shift of 90 degrees. 7 piezoelectric ceramic elements were used to excite two working modes of the vibrator. In order to amplify the amplitude, the comb-tooth structure was designed in the bottom of the vibrator. The vibrator structure was designed and eigenfrequency degeneration was realized by Finite Element Analysis ( FEA) method. The modal test showed that the design scheme was tenable. The excitation and propagation of quasi-traveling wave was proved by tip rotation direction test. The trial motor gave a maximum driving velocity of 162. 5 mm/s and a maximum load of 8. 5 N,while the excitation frequency was 66 kHz and voltage peak-peak was 160 V. The motor can satisfy the preliminary design objective.%探索了在微型直线超声波电动机中实现近似行波驱动的途径,研制了一种外形尺寸为39 mm×6 mm×12.7 mm的环状矩形振子近似行波型直线超声波电动机.结合电机振子的有限元模态分析,阐述了依靠激发空间相位差为90°的两个正交弯曲振动模态,实现行波在环状矩形振子上被激发和传播的电机运动原理.使用7块压电陶瓷片来分别激发振子的两个工作模态.在振子底部设计了梳齿状结构,以放大振幅.利用有限元法进行结构设计,使两个工作模态的频率简并.通过激光测振,证实了电机振子设计方案的有效性.通过对实际样机的驱动齿旋向测试,初步证实近似行波的形成及传播的存在.初步的样机特性实验表明:在频率为66 kHz和160 V峰峰电压激励下,电机最大速度为162.5 mm/s,最大预压力负载为8.5N.该电机初步达到设计目标.