Torque improvement of ultrasonic motor with polymer-based vibrator

为了提高聚合物基超声波电机的性能，我们开发了一种三层振子，由聚合物，精细陶瓷，PZT层，因为精细陶瓷能够大大提高整个振子的刚度。正如预测的那样，三层电机的最大扭矩和最大输出功率分别是聚合物和PZT层电机的5倍和13倍。此外，由于精细陶瓷表现出良好的振动特性以及摩擦性能，我们采用氧化铝制作一种新型的超声波马达。这种直径为35 mm的超声波电机的最大扭矩和最大输出功率分别为1.56 Nm和26.0 W，这两者都大大超过了在相同振动模式下工作的超声波电机所能达到的值。本研究为提高超声波电机的性能提供了一条新的途径。除了对超声波电机的研究外，我们还对聚合物材料的机械衰减进行了基础性的研究。由于机械衰减对聚合物的结晶度影响很大，我们对聚合物进行热退火以改变其结晶度。实验结果表明，在聚苯硫醚的情况下，在150度下退火72小时后，其机械品质因数从400增加到800;这验证了我们的建议的有效性。

To improve the performance of polymer-based ultrasonic motors, we developed a triple-layered vibrator, consisting of polymer, fine ceramic, and PZT layers, since the fine ceramics are capable of greatly enhancing the stiffness of the entire vibrator. As predicted, the maximal torque and maximal output power with the triple-layered motor are 5 and 13 times the values of the previous motor with polymer and PZT layers. In addition, since fine ceramics exhibit good vibration characteristics as well as the frictional properties, we employed alumina to fabricate a new type of ultrasonic motors. This 35-mm-diameter ultrasonic motor provides a maximal torque and maximal output power of 1.56 Nm and 26.0 W, respectively, both of which greatly exceed the values achievable with the ultrasonic motors working in the same vibration modes. This study provides a new approach to improve the performance of ultrasonic motors.In addition to the study regarding ultrasonic motors, we conducted a fundamental investigation on the mechanical attenuation about polymers. Since mechanical attenuation greatly affects the crystallinity degrees of polymers, we carried out thermal annealing on polymers to change their crystallinity degrees. The experimental results show that, in the case of poly phenylene sulfide, its mechanical quality factor increased from 400 to 800 after a 72-hour annealing process at 150 degrees; this validates the effectiveness of our proposal.