| 摘要 |
PURPOSE:To prevent reduction of the damping effect due to invasion of the lubrication oil by forming a fitting part provided on a free edge of a feed screw shaft to be supported by a base table in a canti-lever manner, and a recessed part to remove the lubrication oil invading from the outside to either of the abutting surfaces of a damping member which is freely inserted into this fitting part. CONSTITUTION:A belt pulley 5 to which the driving force is transmitted is fixed to a part projecting from an upstanding part 2 of a feed screw shaft 4 one end part of which is supported by the upstanding part 2 of the base table 1, and a ball nut 6 to be fixed to a slide table 8 is screwed to the intermediate part of the feed screw shaft 4. In this feed screw mechanism, a small- diametered fitting part 9 is formed on the free end of the feed screw shaft 4, a ring member 10 (20) as a damping member is freely inserted thereinto, and when the feed screw shaft 4 is vibrated, damping is executed by colliding of the ring member 10 with the fitting part 9. A screwed groove 22 is formed to the internal circumferential surface 21 of a through hole of the ring member 20 so as to function as a removing part of the lubrication oil, maintaining an appropriate clearance between the ring member 20 and the fitting part 9. |
