| 摘要 |
<p>PROBLEM TO BE SOLVED: To heighten the reliance upon setting of the rotation checking torque while setting the profile low. SOLUTION: An internal gear 2 and epicyclic external gear 3 are installed in a casing 1, and the rotation of an input shaft 4 having an eccentric circle part 11 is transmitted to an external gear 3 through the eccentric circle part 11, and the external gear 3 is left revolving and rotating round its own axis. The rotation is transmitted to the output shaft (valve stem) 5 through a hole 7, pin 6, output boss 14, when deceleration is made by an epicyclic gearing mechanism. The internal gear 2 is fitted to the casing 1 at the whole circumference of the oversurface by means of projection-recess fitting, wherein the fitting is maintained by a spring 18. If the torque from the input shaft 4 is below a certain value, the fitting will not be put loose, and the torque from the input shaft 4 is transmitted to the output shaft 5 upon being decelerated. If any reason causes the output shaft 5 to remain at a standstill, the torque working in the projection/recess fitting becomes over the specified value, and the internal gear 2 is depressed against the action of the spring 18, and the fitting is set off. Accordingly the eccentric motions of the external gear 3 rotate the internal gear 2 while no force is transmitted to the pin 6, and the output shaft 5 remains at a standstill. That is, the torque is shut off.</p> |
