| 摘要 |
<p>An ultrasonic motor with an increased driving force is provided. There is provided a bimorph type piezoelectric actuator 1 formed by integrally stacking six piezoelectric elements 11, 12, 13, 14, 15 and 16. The piezoelectric element 12 is thinner than the piezoelectric element 11, and expands and contracts in the same direction as that of the piezoelectric element 11 at the same voltage, and the piezoelectric element 13 is thinner than the piezoelectric element 12, and expands and contracts in the same direction as that of the piezoelectric element 11 at the same voltage. The piezoelectric element 14 contracts and expands oppositely to the piezoelectric element 11 at the same voltage; the piezoelectric element 15 is thinner than the piezoelectric element 14, and contracts and expands in the same direction as that of the piezoelectric element 14 at the same voltage; and the piezoelectric element 16 is thinner than the piezoelectric element 15 and contracts and expands in the same direction as that of the piezoelectric element 14 at the same voltage. Therefore, the expansion and contraction of each of the piezoelectric elements 11, 12, 13, 14, 15 and 16 contribute to a driving force without interfering with the expansion and contraction of the other piezoelectric elements. Since the piezoelectric actuator 1 therefore has a simple structure and has higher output and efficiency than those available in the prior art, its size and power consumption can be smaller compared to those of conventional devices having the same output. <IMAGE></p> |
