| 摘要 |
A high helix, multi threaded screw shuttle transfer assembly (l0) for transferring high load devices at high speeds includes a screw (l8) having threads (23). Standoff brackets (26) and bearing housing (36) rotatably support and journal the ends (20,22) of the screw (l8). A drive motor (50) connected by a belt (52) to a pulley (48) on the screw (l8) rotates the screw (l8). A nonrotatable nut (54) having threads (56) coactive with the threads (23) of the screw (l8) travels along the longitudinal length of the screw (l8) during rotation thereof. The assembly (l0) is characterized by the threads (23,56) of the nut (54) and the screw (l8) each being high helixed and multithreaded. The threads (56) of the nut (54) are formed about the threads (23) of the screw (l8) for providing multipoint full thread contact completely about the screw (l8) and minimizing tolerances between the threads (23) of the screw (l8) and the threads (56) of the nut (54) to move the nut (54) at high speeds between the ends (20,22) of the screw (l8). Further, a method of forming the threads (56) of the nut (54) on the lead screw (l8) of the nut drive and lead screw assembly (l0) is provided. |
