口齿式定子驱动的平面超声电机特性分析

Property Analysis of Planar Ultrasonic Motor Driven by Teeth-shaped Stator

推出口齿形定子驱动的压电平面电机,选定子的面外弯振、面内横齿弯振、面内纵齿弯振作为工作模态,利用面外弯振分别与面内纵齿弯振、面内横齿弯振的振动耦合,分别在纵、横齿驱动足上生成沿xOz、yOz面行进的椭圆轨迹,以推动动子沿x、y向移动,阐明了电机的运动原理。基于频率一致性目标优化了定子尺寸,并厘定电机最适驱动频率为30 800 Hz。建立了定子机电耦合分析模型,计算出定子的瑞利阻尼,模拟出驱动足的椭圆轨迹,仿真得到在250 V电压激励时驱动足的x、y、z向振幅分别为2.1μm、2.6μm和2.0μm。探析了驱动电压、频率、相位差对电机振幅的影响。

A piezo-plane motor driven by the teeth-shaped statoris presented in this paper.The out-of-plane bending vibration,in-plane transverse tooth bending vibration,and in-plane longitudinal tooth bending vibration were selected as the working modesof the stator.Through the vibration coupling of the out-of-plane bending vibrationwith the in-plane longitudinal tooth bending vibration and the in-plane transverse tooth bending vibration respectively,the elliptical trajectories along the xOz and yOz planesare generated on the longitudinal and transverse teeth driving feet respectively to drive the movers to move along the x and y directions.The motion principle of the motor is introduced.The stator size is optimized based on the frequency consistency objective,and the optimum driving frequency of the motor is determined to be 30 800 Hz.An electromechanical coupling analysis model of the stator is established.The Rayleigh damping of the stator is calculatedand the elliptical trajectories of the driving feet are simulated.The simulation results show that the amplitudes of the driving feet at the x -direction,y -direction and z -direction are 2.1 μm,2.6 μm and 2.0 μm respectively at 250 V of voltage excitation.The influences of the drive voltage,frequencyand phase difference on the motor amplitude are analyzed.