| 摘要 |
PURPOSE:To enable steel balls of circulating smoothly and noiselessly by providing a nut which is screwed on the external periphery of a screw shaft, with a deflector which has on the internal periphery thereof a concaved part transversely running the screw thread which is formed on the nut to connect both the adjacent screws. CONSTITUTION:A nut 4 which is screwingly engaged via steel balls 5 on a screw shaft 2 on which a screw thread 3 is formed at a specified pitch has the screw thread 6 shaped on the internal periphery thereof, the pitches P1 and P2 between the bottoms of the screw thread 6, 6 on the middle side of the nut being longer than the other pitches P3 and P4. The nut has ellipsoidal through-holes 7 and 8 which are axially deviated at the top part and the bottom part of the internal periphery thereof and a deflector 9 is engaged and settled in each of the holes 7 and 8. This deflector 9 has a concaved part 9b having the curved bottom part 9a and the depth of the concaved part 9b is greater than the diameter of each of the steel balls 5. An angular contact ball bearing 12 which bears the axial and the radial loading is mounted on the external peripheral face of the nut 4. |
