To prevent balls from bumping against each other when a nut moves down, to ensure smooth rolling of the balls when a ball screw is vertically used.
A cylindrical recess 13 is formed in a lower part of a straight path 11. The recess includes a ball delivering member 5 having a ball passing hole 6. A protrusion 61 for making the inner diameter of the ball passing hole 6 smaller than the diameter of the ball 3 is formed radially outside the ball passing hole 6 so as to be elastically deformed. The ball 3 falling from the straight path 11 temporally stops on the protrusion 61 in the ball delivering member 5. The protrusion 61 elastically deforms by the weight of the ball 3. The returning force of a movable piece 53 having opened outward delivers the ball 3 to a curved path 41. Each of the plurality of balls 3 is delivered to the curved path 41 at intervals.
| JPH08118186 | FEED SCREW MECHANISM |
| JPH11270646 | MULTIPLE THREAD BALL SCREW AND SEALING DEVICE THEREOF |
| JP6198111 | Sliding device |
Megumi Konishi
Hide Tanaka Tetsu
Ichi Hirose
Toru Miyasaka