A miniaturized resonant-type smooth impact drive mechanism actuator

A smooth impact drive mechanism (SIDM) is one type of piezoelectric actuator that has been put into practical use. In previous SIDMs, soft-type multilayered piezoelectric elements with low mechanical quality factors were utilized, which meant it was difficult to generate high output power, and the multilayered structure was an obstacle to further miniaturization. We have proposed a resonant-type SIDM actuator, which has a simple structure, and uses combined resonant vibrations to achieve high output power. In the present study, a simple plate transducer was designed to realize the resonant-type SIDM principle. This compact actuator was composed of a hard-type single-layer piezoelectric element. The stator transducer was 10 mm long and 2 mm wide. Instead of a linear slider, a small bearing (6 mm in diameter) was used as a moving part and was successfully driven based on the resonant-type SIDM principle. The voltage frequency was 288.0 kHz for the first mode and 576.0 kHz for the third mode, which was twice that of the first mode. By adjusting the preload and the phase difference between each voltage, the bearing was rotated at 400 rpm. In addition, the driving direction could be reversed by modifying the phase difference.