Improvement in efficiency and life of ultrasonic motor by introducing lubrication mechanism

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K13896
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Dynamics/Control
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Nakamura Kentaro 東京工業大学, 科学技術創成研究院, 教授 (20242315)
• Research Collaborator: Wei Qiu Technical University of Denmark, Post-doctoral fellow
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 超音波 / 超音波モータ / 摩擦駆動 / 潤滑 / 潤滑油 / 効率 / トルク / 圧電素子

Outline of Final Research Achievements

Ultrasonic motor is an actuator driven by high frequency vibration through friction force, and provides quick response and high torque-to-weight ratio. But its application has been restricted to special areas such as auto-focusing in camera and other precise positioning systems because its efficiency and life were limited. To overcome this problem, this study introduced lubricant in the friction interface between the rotor and vibrator, and then succeeded in developing efficient and durable ultrasonic motor. We carefully researched on the conditions of preload and vibration amplitude. The efficiency has been improved from 40% to 70% in hybrid transducer-type ultrasonic motors. Our experiments also proved that the life was successfully extended, and the operation stability was improved. In addition, the effects of the lubricant characteristics and the materials of contacting surfaces were experimentally investigated.

Free Research Field

超音波工学