Bar-shaped ultrasonic linear motor using traveling wave along rod with bimorph transducers

By using a pair of bimorph transducers, we have already miniaturized a traveling-wave-based ultrasonic linear motor and achieved a diameter of <; 10 mm, but its motor performances were not sufficient for practical applications. In this study, in order to improve its performances, the motor structure is optimized with the two methods: by reducing the thickness of the transmission bar, and by increasing the number of the bimorph transducers. The highest motor speed of 118 mm/s is achieved with the former, while the largest motor thrust of 0.5 N is obtained with the latter. These values are approximately 25 and 15 times as large as those in our previous experiments.