| 摘要 |
PURPOSE:To facilitate control and to decease the number of components by making a specific part of a rotary body abut on the internal circumferential surface of a cylinder body and converting the quality of displacement given to the rotary body by the expanding operation of piezoelectric elements into the quantity of feeding in straight direction. CONSTITUTION:A voltage applying means 8 applies reverse-directional voltages to piezoelectric elements 4 and 5 fixed so that they expand at right angles to the direction of the rotary shaft part 13 of the rotary body 3. Consequently, forces which are exactly as large as each other and in reverse directions between inertia bodies 6 and 7 operate on the elements 4 and 5. Thus, the rotary body 3 and the cylinder body 2 rotate with a shaft part 13 as one axis sand the force of rotary movement is sent to a converting means 9 to move an output member 20 linearly as shown by an arrow B. One rotation of the rotary body 3 is made in steps corresponding to one cycle of the expanding operation of the elements 4 and 5, which can be controlled in minimum steps to control desired fine feeding. |
