ULTRASONIC VIBRATOR AND ULTRASONIC LINEAR MOTOR OR ULTRASONIC MOTOR USING IT

摘要

PROBLEM TO BE SOLVED: To improve the starting torque and thrust of an ultrasonic linear motor or ultrasonic motor by constituting a laminated piezoelectric element of a piezoelectric element having a specific mechanical quality factor. ;SOLUTION: The piezoelectric element used for a laminated piezoelectric element 12 is constituted by piling up several tens or hundreds of so-called hard type PZT piezoelectric elements having a size of 2mm×3.1mm×9mm. Each single plate 18 constituting the element 12 is provided with an electrode 19. In addition, insulating sections 17 of about 0.5-0.1mm are provided at three locations at the end section of the single plate 18 and, only at one end section, the electrode 19 is provided to the side edge. A piezoelectric ceramic having a mechanical quality factor (Qm) of ≥500 (when 1 Vp-p is measured) is used for forming the single plate 18. The element 12 is constituted by piling the single plates 18 upon another so that their directions of polarization can alternately become opposite to each other.;COPYRIGHT: (C)1997,JPO