中文摘要：

设计了一种双振子自走型直线超声电机，电机的定子由2个同轴的对称布置的弯曲摇头型振子和中部带细颈的柔性振动块组成．2个振子的弯曲振动会激励出中间振动块的摇头振动，使驱动头上的质点产生椭圆运动轨迹，与导轨摩擦接触产生自走直线运动．测量得到定子上振动块的局部弯曲共振频率为20792Hz，定子的弯曲共振频率约为40420Hz．仿真发现，以振动块的局部弯曲共振模态作为工作模态能够得到更大的振幅．实验结果表明，在该模态频率下，电机可以提供较大的驱动速度，发热很少，较长时间工作仍旧稳定可靠．故被选作工作模态．在40420Hz附近电机能够驱动，但是振子发热严重，不易稳定工作．当两相驱动信号的频率为20．8kHz、相位差为90°、驱动信号电压的峰峰值为138V时，电机的驱动速度达到598mm／s，电机的最大驱动力达到1．94N．

英文摘要：

A self-driving linear ultrasonic motor with double vibrators was developed. The stator consists of two vibrators and a mass. The mass is in the middle of the stator. Each vibrator is symmetrically connected with one side of the mass by a slender shaft. The bending vibrations of two vibrators inspire a wobbling motion of the mass. Therefore, the locus of particles on the driving head is an ellipse. The friction force between the mass and the leader drives the motor moving itself. The measured local bending resonant frequency of the mass is about 20 792 Hz, and that of the stator is about 40 420 Hz. Emulation results showed that when the local bending resonant mode of the mass is used as working mode, the vibration amplitude of the mass is large. Experimental results showed that the driving speed of the motor is high and the motor can work stably with little temperature rise when the mass working in the local bending resonant mode. But when the bending resonant mode of the stator is used as working mode, the temperature rise of the stator is high, therefore the motor cannot work stably. The characteristics of the prototype motor were measured experimentally. The maximum speed of the motor is about 598 mm/s, and the maximum driving force is over 1.94 N, when the phase difference of the applied two signals is 90° and the peak tO peak driving voltage is 138 V at the frequency of 20.8 kHz.