基于十字压电超声换能结构的平面超声电机研究

Planar Motor Driven by Cross Structured anUltrasonic Transducer

为了丰富平面超声电机的驱动原理及结构型式,提出十字形压电超声换能式定子驱动的平面超声电机。选定该定子横向杆的面内弯振、纵向杆的面内弯振以及定子的面外弯振作为电机的工作模态。通过面外弯振模态分别与横向杆的面内弯振、纵向杆的面内弯振进行振动耦合,在驱动足上生成沿yoz面和xoz面行进的椭圆轨迹,推动动子交替沿x、y向平移。阐明了该电机的工作原理,基于定子频率一致性工作模态要求,并厘定出最适合驱动频率为24 650 Hz,优化了定子尺寸为25.5 mm×5 mm×5.9 mm。建立定子的FEM模型,对电机进行瞬态分析,当驱动电压250 V时,得到驱动足的x、y、z向振幅可达到3.1、6.2、4.3μm。该电机可望产生较大动力与速度。

Due to the output amplitude of the planar motor driven by an X-shaped piezoelectric vibrator was fairly smaller, a planar motor resonantly driven by a cross-structure stator was proposed. It selected all the in-plane bending vibration mode of the transverse bar, the in-plane bending mode of longitudinal bar, and the out-of-plane bending mode of the stator as working modes. By coupling out-of-plane bending mode with transverse bar ’s in-plane bending mode and the longitudinal bar ’s in-plane bending mode, the elliptical trajectories along the yoz and xoz planes respectively were generated in the driving feet, so that the slider could be pushed to move along x, y directions. The working principle of the motor is explained. According to the requirement of working modal frequency consistency, the size of stator is optimized to be 25.5 mm × 5 mm × 5.9 mm.A FEM model for the stator was established,with which the optimal driving frequency was calculated to be 24 650 Hz, Transient analysis was also carried out which exhibited that the driving feet vibration amplitude along x, y, and z directions could reach 3.1, 6.2 and 4.3 μm when 250 V voltage was applied.It was shown that the stator hadproduced greater power and speed.