Load characteristics of ultrasonic rotary motor using a longitudinal-torsional vibration converter with diagonal slits. Large torque ultrasonic rotary motor

The characteristics of an ultrasonic rotary motor using a longitudinal-torsional vibration converter with a large torque are studied. To obtain a large torque, ultrasonic motors using a slitted longitudinal-torsional vibration converter are proposed. The converters have rather simple structures and are driven using only a longitudinal vibration transducer. The vibration converters have 8 to 16 diagonal slits of 45 Alpha degrees and 0.5 to 1.0 mm width. The designed ultrasonic motors consist of a vibration converter with a driving part at its free edge, and a rotor part pressed statically to a driving surface using corned disk springs. Characteristics of these motors are measured under loading by various weights. Maximum torques over 0.3 to 23 Nm were obtained by converters of 15 to 60 mm in diameter and of 56 to 23 kHz in frequency. Maximum revolution obtained was over 290 r.p.m. using a 15 mm diameter motor of 56 kHz.