摘要 |
A ball circulating member (12) constructed in an external face of a nut (2) is provided with ball scooping sections (15,16) for scooping up balls (6) rolling on between ball screw grooves (3,4) of a screw shaft (1) and the nut (2), along a line tangent to a center orbital circle of the balls. The path length (L) of a ball scooping path section (19) formed in the ball scooping sections is set to be 1/2 or greater of the diameter of the ball (6). |