| 摘要 |
PURPOSE:To increase the range of application of a rotary driving body, by a method wherein an annular oscillating element, generating the longitudinal wave of (n)th-order, higher than second-order, is employed to form the rotary driving body. CONSTITUTION:An annular oscillating element 1 consists of ceramics electrostriction elements and is provided with a whole surface electrode 2 on one surface thereof while the other surface of the same is divided into four equal sectors and respective sectors are provided with split electrodes 3a, 3b. Further, the electrodes are polarized in the direction of the thickness thereof so that the directions of the polarizations of the neighboring sectors are reversed with each other. Piezo-electric laminates 5a-5d are fixed on the partial surfaces of the whole surface electrode 2, corresponding to the split positions of the split electrodes 3a, 3b, through an insulation layer. Said piezo-electric laminate 5a is arranged so as to coincide with the maximum amplitude position of said oscillating element 1 and the end face thereof is abutted against a driven body 10. According to this constitution, neighboring two pieces of piezo-electric laminates are expanded sequentially and alternately by impressing alternated voltage on the opposing split electrodes 3a, 3b respectively, whereby a force having the same rotating direction is exert on the driven body 10. |
