An ultrasonic motor using transmission line and horn with oblique slits driven by a Langevin transducer

An ultrasonic micro-motor usually has small torque because of its small size of the transducer. If the micro-motor is driven by large size transducer, we can expect better motor characteristics. In this research, a Langevin transducer with 31.5 mm in diameter is used to drive a rotor with 5 mm in diameter. Newly designed horn with oblique slits is used for vibration mode conversion, then elliptical motion at the driving surface is obtained for friction drive. The driving frequency was about 48.9 kHz. The maximum revolution speed of about 102 r.p.m. at applied voltage of 50 Vp-p, the maximum torque of about 86 μNm at 50 Vp-p and 60 Vp-p, and the maximum driving efficiency of about 0.018 % at 40Vp-p were obtained.