Gouda Yasuyuki, Nakamura Kentaro, Ueha Sadayuki
Precision and Intelligence Laboratory, Tokyo Institute of Technology, R2-25 4259 Nagatutacho Midori-ku Yokohama-shi, Kanagawa 226-8503, Japan.
Ultrasonics. 2006 Dec 22;44 Suppl 1:e617-20. doi: 10.1016/j.ultras.2006.05.015. Epub 2006 Jun 2.
Multi-degree-of-freedom ultrasonic actuator has been studied for robot arms and multidimensional precision table and so on because of its simple structure, silent operation, and holding force. In this study, we aim to miniaturize multi-degree-of-freedom ultrasonic actuator for fabrication on a substrate. This actuator consists of a stainless steel cylinder and a PZT ring. The cylinder is fixed on a substrate and the PZT ring is glued to the substrate near the cylinder. The 1st longitudinal vibration and the 2nd bending vibration are simultaneously excited in the cylinder to make elliptical motion at the top of the cylinder and a ball rotor placed on the cylinder rotates because of the friction force. Length of the cylinder was decided so as to tune the resonance frequency of the 1st longitudinal vibration to the 2nd bending one. Actuator performances are evaluated experimentally using a 14 mm height and 7 mm diameter stainless steel cylinder with a 0.5 mm thickness PZT ring. The rotation about the cylinder axis is tested using the two orthogonal bending vibrations with 90 degrees phase difference. Also, the rotation about horizontal axes were investigated using the combination of the longitudinal vibration and one of two bending vibrations. We measured the rotation speed of a steel ball and obtained 15.8 rps using a 6 mm diameter ball rotor.
多自由度超声致动器因其结构简单、运行静音和具有保持力等特点，已被用于机器人手臂和多维精密工作台等领域的研究。在本研究中，我们旨在将多自由度超声致动器小型化，以便在基板上制造。该致动器由一个不锈钢圆柱体和一个PZT环组成。圆柱体固定在基板上，PZT环粘贴在圆柱体附近的基板上。在圆柱体内同时激发第一纵向振动和第二弯曲振动，使圆柱体顶部产生椭圆运动，放置在圆柱体上的球形转子因摩擦力而旋转。圆柱体的长度是为了将第一纵向振动的共振频率调谐到与第二弯曲振动的共振频率相同而确定的。使用高度为14毫米、直径为7毫米的不锈钢圆柱体和厚度为0.5毫米的PZT环对致动器性能进行了实验评估。利用相位差为90度的两个正交弯曲振动测试了绕圆柱体轴线的旋转。此外，利用纵向振动和两个弯曲振动之一的组合研究了绕水平轴的旋转。我们测量了钢球的转速，使用直径为6毫米的球形转子时获得了15.8转/秒的转速。
