ねじれ/曲げモードに基づく回転式超音波モータにおいて高トルク密度と高パワー密度を達成した論文が IEEE Transactions on Industrial Electronics に掲載されました。中国の山東大学の呉助教が中心となって進めた共同研究の成果です。本ジャーナルの最新の Impact Factor は 7.5 以上です。
J. Wu, Y. Mizuno, and K. Nakamura, “A rotary ultrasonic motor operating in torsional/bending modes with high torque density and high power density,” IEEE Trans. Ind. Electron., vol. 68, no. 7, pp. 6109-6120 (2021).
To achieve high torque density and high power density of rotary ultrasonic motors (USMs), in this article, we develop a rod-shaped transducer operating in torsional/bending (T/B) modes and excite two elliptical motions on its bilateral ends to drive the rotor orthogonally pressed onto the transducer. Here, the torsional vibration, the driving structure, and the rod shape may enable the T/B motor to provide high driving force, large driving distance, and low weight, which facilitate the realization of high torque density and high power density. To assess the validity, first we construct a transducer 43 and 110 mm in diameter and length, respectively. Then we investigate the load characteristics of the T/B motor: When it works at the frequency of 21.64 kHz, the maximal torque and the maximal output power reach 10.1 N·m and 38.1 W, respectively. In the meantime, it yields the torque density and the power density of respectively 20.0 N·m/kg and 75.7 W/kg, which are, as predicted, relatively high compared to the values of most conventional rotary motors. This article not only validates the effectiveness of our proposal but also provides a new approach to design powerful rotary USMs.