摘要 |
1,243,434. Toothed gearing. SVENSKA KULLAGERFABRIKEN A.B. 26 June, 1969 [27 June, 1968], No. 32434/69. Heading F2Q. Rotation of a shaft 3 is transformed into translational movement of a frame structure 22 by mechanism comprising a multi-thread screw member 1 on shaft 3 meshing a plurality of screw-threaded planet rollers 4 carried in a cage 6, 7, the rollers 4 meshing a fixed half-nut 17 of length greater than that of the screw member 1 and meshing a half-nut 19 of length corresponding substantially to that of screw member 1 and secured to frame structure 22. The rollers 4 are provided with toothed ends 13, 14 which mesh teeth 15, 16 on annular members 8, 11 secured to the ends of screw member 1. The pitch of the nut 19 is so selected that the pitch of the assembly comprising the driving screw member 1, the planet rollers 4, and the nut 19 is zero. The driving screw member 1 may consist of two externally screw-threaded half-rings adapted to slide without rotating on a common shaft in order to take up play. |