非接触压电微马达的仿真与实验研究

Simulation and experimental study of non-contact piezoelectric micromotor

提出了一种基于四区和八区2种激振方式的新型非接触压电微马达,并进行了振动模态的有限元数值模拟。利用ANSYS有限元软件对定子进行模态分析,并用激光测振仪对四区和八区2 种激振方式下的定子进行位移扫频和振型测试,得出:最优驱动频率分别为34.4 kHz和46.3 kHz,相应的模态分别为B21和B22,二者结果吻合较好。对微马达的输出性能进行了实验研究,结果表明:三叶片和六叶片转子在八区最优模态激振下转子的转速约是四区的2倍。说明了增加定子的分区数不仅改变了定子的最优驱动频率而且能够明显提高转子的转速。而且当A B间相位差从90°调谐到270°时,行波的传播方向发生了改变,从而实现了转子的换向。实验还表明,转子的正反转的转速基本一致。

A new non-contact piezoelectric micromotor was presented, based on four-sector and eight-sector excited by electric signals. The mode analysis of the stator was carried out to compute the natural frequency and the corresponding vibration mode by finite element method. The frequency sweep and the vibration mode test were done with a laser Doppler vibrometer. It is shown that the optimum driving frequencies of the stators divided into four-sector and eight-sector arc 34.4 kHz and 46.3 kHz, and the corresponding vibration mode were B21 mode and B22, respectively. It is found that the finite element simulation results were in good agreement with experiment. The output characteristics of micromotor were tested. The conclusion is that the revolution speed of the optimum driving frequency of eight-sector is about double than four-sector for three blades and six blades rotors. These demonstrate that the increase of the sector number of stator can not only change the optimum driving frequency, but also increase the revolution speed of rotors obviously. When the difference between A and B phase is changed between 90° and 270°, the direction of the traveling wave along circumferential direction is shifted, so the rotation direction of rotor is also changed, the experiment shows that the non-contact piezoelectric micromotor offers identical performance to different rotation directions.