A novel in-plane mode rotary ultrasonic motor

• Published in: Chinese journal of aeronautics Vol. 27; no. 2; pp. 420 - 424
• Main Authors: Lu, Xiaolong, Hu, Junhui, Yang, Lin, Zhao, Chunsheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2014
• Subjects: Bearings; Excitation; In-plane vibration; Langevin transducers; Motors; No-bearing; Rotary driving; Screws; Space applications; Stators; Torque; Transducers; Ultrasonic devices; Vibration mode; 压电马达; 平面模式; 操作条件; 旋转; 空间应用; 航空航天环境; 超声波马达; 超声电机; Langevin transducers; Ultrasonic devices; Rotary driving; In-plane vibration; No-bearing
• ISSN: 1000-9361
• DOI: 10.1016/j.cja.2013.07.002

Ultrasonic motors have the merits of high ratio of torque to volume, high positioning precision, intrinsic holding torque, etc., compared to the conventional electromagnetic motors. There have been several potential applications for this type of motor in aerospace exploration, but bearings and bonding mechanism of the piezoelectric ring in the motors limit the performance of them in the space operation conditions. It is known that the Langevin type transducer has excel- lent energy efficiency and reliability. Hence using the Langevin type transducer in ultrasonic motors may improve the reliability of piezoelectric motors for space applications. In this study, a novel in-plane mode rotary ultrasonic motor is designed, fabricated, and characterized. The proposed motor operates in in-plane vibration mode which is excited by four Langevin-type bending vibra- tors separately placed around a ring-shaped stator. Two tapered rotors are assembled to the inner ring of the stator and clamped together by a screw nut. In order to make the motor more stable and convenient to fix, a thin cylindrical support is placed under the stator ring. Due to its no-bearing structure and Langevin transducer excitation, the prototype ultrasonic motor may operate well in aeronautic and astronautic environments.