Experimental characteristics of a bolt-clamped short-cylindrical torsional vibrator using shear mode piezoceramics inserted in the axial direction

A torsional vibrator using shear mode piezoceramics inserted in the axial direction, developed 20 years ago for use in a mechanical filter exhibits good vibration performance. The authors applied this torsional vibrator to a high-power transducer shaped as a short cylinder with a large diameter. In this case, the torsional vibrator can easily be fabricated by bolt-clamping in the radial direction, and the small number of parts is beneficial to the fabrication. The vibrational characteristics of the torsional vibrator were determined previously using finite element analysis. In this paper, we report the results of a trial fabrication of such a torsional vibrator. As a result, it is clarified that this torsional vibrator exhibits superior vibration performance such that it could be applied to an ultrasonic high-power transducer, and that the torsional and bending vibrations on the disk are easy to couple to each other according to the dimensions of the vibrator.