| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a linear actuator using piezoelectric elements with a simple structure capable of reducing the number of parts. <P>SOLUTION: A first screw member 12 and a second screw member 11 are configured to be mutually screwed. When the edges of a plurality of piezoelectric elements 13 abut against the outer circumference of the first screw member 12 to apply an AC voltage to the piezoelectric elements 13 and generate a progress wave, the first screw member 12 rotates relative to the second screw member 11 and moves in an axis L direction. At this time, resiliency generated by a torsion spring 14 gives a torque around an axial line L to the first screw member 12. Therefore, the screw threads of the first and second screw members 12, 11 are brought into intimate contact with each other and concurrently a preload to press the first screw member 12 onto the edges of the plurality of piezoelectric elements 13 can be generated. As a result, the progress wave can be effectively generated on the first screw member 13 by the piezoelectric elements 13 with a minimum number of parts. Further, the progress wave is effectively conveyed from the first screw member 12 to the second screw member 11 to enable the first and second screw members 12, 11 to be relatively rotated. <P>COPYRIGHT: (C)2010,JPO&INPIT |
