金属方柱压电片复合微型超声电机的研制

A novel ultrasonic motor with quadrate bar

研制了一款金属方柱压电片复合微型超声电机。相对于圆柱型电机,这种形式的电机的电场极化更充分,以及信号线的焊接更易实现。定子帽的材料用钢或铜。文中计算了整个电机定子换能器的模态和谐响应,理论上分析了不同方向转动惯量一致,可以形成椭圆运动的原理。实验测试了电机的共振频率、转速、转矩等。结果表明这款电机的自由共振频率约100kHz,无载转速可达到6000r/min以上,最大转矩可达60!Nm以上,理论和实验基本一致。该电机具有很好的实用化前景。

A novel miniature ultrasonic motor is described. The stator consists of a quadrate metal bar and 4 piezoelectric plates. The metal bar uses brass with a dimension of 1.6×1.6×6.6mm^3. The piezoelectric plates are made of PZT-4 and bonded to the sides of metal bar, all sized 1.6×6×0.3mm^3 and polarized in the direction of thickness. Compared with traditional cylindrical ultrasonic motors, the quadrate cross-section motor makes polarization more sufficient, and signal wires easier to be welded. Modal and harmonic analysis of the stator is performed using FEM. The paper also shows the principle that inertial moments are equal in different directions of quadrate bar, so the motion trace of surface particle can be ellipse. Output characteristics of the USM is measured and compared with the FEM. The resonance frequency, maximum torque, and unloaded revolution are more than 100 kHz, 60 mNm and 6000 rpm, respectively, basically in agreement with the theory. The miniature ultrasonic motor has potential applications.