In this article, to achieve high torque density and high power density of rotary ultrasonic motors (USMs), 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.

中文翻译：

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一种高扭矩密度和高功率密度的扭转/弯曲模式旋转超声波电机


在本文中，为了实现旋转超声电机（USM）的高扭矩密度和高功率密度，我们开发了一种以扭转/弯曲（T/B）模式工作的杆状换能器，并在其双边端激发两个椭圆运动来驱动转子正交地压在传感器上。这里，扭转振动、驱动结构和杆形状可以使T/B电机提供高驱动力、大驱动距离和低重量，有利于实现高扭矩密度和高功率密度。为了评估有效性，首先，我们构建了直径和长度分别为 43 毫米和 110 毫米的传感器。然后，我们研究了T/B电机的负载特性：当工作频率为21.64 kHz时，最大扭矩和最大输出功率分别达到10.1 N·m和38.1 W。同时，它产生的扭矩密度和功率密度分别为20.0 N·m/kg和75.7 W/kg，正如预测的那样，与大多数传统旋转电机的值相比相对较高。本文不仅验证了我们建议的有效性，而且提供了一种设计强大的旋转 USM 的新方法。