双十字压电振子同型弯振模态驱动的平面超声电机

为了丰富平面超声电机的型式，提出一种双十字压电振子同型弯振模态驱动的平面超声电机。利用双十字压电振子的纵杆面内、面外弯振耦合以及横杆面内、面外弯振耦合，分别在两杆的驱动足上合成沿xoz、yoz面行进的两相椭圆轨迹，以交替地推动动子沿x、y向移动。分析了该平面超声电机的驱动机理，并推导出两相椭圆轨迹方程。建立了双十字压电振子机电耦合模型，对其三相工作模态的振型进行仿真分析，并在结构优化的基础上实现了三相工作模态频率一致，使它们分别为43 468，43 552和43 569 Hz。仿真了双十字压电振子的频响特性并实现了干扰模态分离，当驱动电压为250 V时，驱动足x、y、z向振幅分别为1.3，0.8和0.9 μm，满足电机驱动要求。模拟得到定频激励下双十字压电振子驱动足的两相椭圆运动轨迹，验证了所设计平面超声电机驱动机理的有效性。该平面超声电机可输出较大速度与动力，具有广阔的应用前景。

Planar ultrasonic motor driven by same type bending modes of dual-cross piezoelectric vibrator

In order to enrich the structure of planar ultrasonic motor, a planar ultrasonic motor driven by same type bending of dual-cross piezoelectric vibrator was proposed. With the in-plane and out-of-plane bending coupling of the longitudinal bars and crossbars of the dual-cross piezoelectric vibrator, two elliptical trajectories along xoz and yoz planes were synthesized on the two-rod driving feet to alternately push the mover along the x, y directions. The driving principle of the planar ultrasonic motor was analyzed, and the elliptial trajectory equation was derived. The electromechanical coupling model of the dual-cross piezoelectric vibrator was established, and the three-phase working modes were simulated. Based on structure optimization, the frequencies of three-phase working modes were consistent, which was 43 468, 43 552 and 43 569 Hz. The frequency nesponse characteristics of the dual-cross piezoelectric vibrator were simulated and the interference mode separation was realized. When the driving voltage was 250 V, the amplitude in x, y and z direction of the driving foot were 1.3, 0.8 and 0.9 μm, respectively, which met the motor drive requirements. The two elliptical trajectories of the dual-cross piezoelectric vibrator driving foot under the constant frequency excitation was simulated，which verified the effectiveness of the driving principle for the designed planar ultrasonic motor. This planar ultrasonic motor is expected to output greater speed and power, which has broad application prospects.