| 摘要 |
PURPOSE:To improve transfer accuracy by fitting and fixing a pair of magnets arranged at a certain interval onto a feed nut and fixing and fixed onto a movable part, allowing an intermediate magnet to be interposed between the both magnets, thus preventing the error on the driving side such as a feed-screw shaft, etc. to be transmitted to the movable part. CONSTITUTION:A feed nut 12 is screwed with a feed screw shaft 11 revolved by a motor, etc., and two housings 13 and 15 are fixed at a certain interval in the axial direction onto the outer periphery of the nut 12. The first and the second annular magnets 14 and 18 are fixed into the circular concaved parts which are formed so as to be opposed to each other into the housings 14 and 15, respectively. A stop device 19 for the turn of the feed nut 12 is installed into the housing 13. A housing 21 fixed onto a movable part 20 is interposed between the both housings 13 and 15, keeping a proper gap for the housings 13 and 15, and an intermediate magnet 23 having the magnetic poles which repel the respective magnets 14 and 18 is fixed in the housing 21. |
