| 摘要 |
569,245. Screw-and-nut mechanism. HOFFAR, H. S. Aug. 6, 1942, No. 10996. [Class 80 (iii)] In screw-aud-nut mechanism wherein loadcarrying balls are arranged in the threads, and balls of slightly smaller diameter alternate with these and are all circulated in a closed orbit, the curvature of the cross-section of the helical groove is complemental to the ball curvature and the diameter of the bearing balls is such that they seat in the bottoms of the helical grooves and are engaged by these grooves over arcs which, in the aggregate, comprise the greater portion of the ball circumference. The screw 1 has a helical groove 10 between which and the corresponding groove in the nut 2 are arranged load-carrying balls 3. and balls 30 of slightly smaller diameter, the grooves having a cross-section slightly less than a semicircle. The balls are circulated through a by-passage 21, at the ends of which are conical-ended deflecting screws such as 23. In a modification, Fig. 6, a keyway 24, of lesser depth than the helical groove, for engagement by a member movable lengthwise of the screw but rotatable with it. |
