| 摘要 |
PURPOSE:To provide a tube tunnel-type ball screw which can smoothly run a ball in a pipe by forming a substantially semicircular return pipe fitted to the outer periphery of a nut and forming opening portions for scooping up a ball on both ends of the pipe. CONSTITUTION:A return pipe 10 is formed in a substantially semicircle having a radius (r), and tangue pieces 11, 12 are formed on opening portions thereof for scooping up a ball 13. On the other hand, a nut 14 of a ball screw having a screw groove 15 formed on the inner periphery thereof is provided with through holes 16, 17 formed thereon for guiding a ball 13 in the pipe to the opening portions 11, 12. Semicircular vertical walls 18 are formed on the through holes 16, 17 at the outward side of the nut 14, and semicircular curved walls 19 are formed on the inward side thereof. A return pipe presser 20 is fixed to a flat surface 21 by a vis 22. This results in that the ball 13 is scooped up by the tangue piece 11 with rotation of a screw shaft 23 to smoothly run in the return pipe 10 and move the nut 14. |
