| 摘要 |
<p>A ball screw, wherein wear is hard to occur on a bilge-shaped picking part even if the ball screw is rotated at high speeds with a high DN value, and a movement guiding device. The bilge-shaped picking part (42) having a groove (41) gradually narrowed toward the inside of a circulation passage (25) is formed on the circulation member (28) of the ball screw. Balls (23) rolling in the ball rolling groove (21a) of a screw shaft (21) are picked up to the inside of the circulation passage (25) of the circulation member (28) while holding them by both sides of the groove (41) of the bilge-shaped picking part (42). A lip part (43) projecting into the ball rolling groove (21a) of the screw shaft (21) is formed on the bilge-shaped picking part (42). Both the bilge-shaped picking part (42) and the lip part (43) are brought into contact with the ball (23) at a picking point P where the bilge-shaped picking part (42) starts to pick up the ball (23) from the ball rolling groove (21a) of the screw shaft (21).</p> |
