| 摘要 |
PROBLEM TO BE SOLVED: To realize a processing cost reduction with a good mass productivity of nuts in the case of a large amount of lot articles. SOLUTION: In the ball screw 1 comprising a thread shaft 2 and a nut 3, the nut 3 is made of a sintered alloy. Such a nut made of a sintered alloy is obtained by plastically preparing a metal powder and sintering it after injection molding. A sintered alloy with a possible cementation hardening is preferable as the sintered alloy. The injection molding is easily applied in the case of a part having a small diameter and therefore, it is desirable that the nut 3 is divided and formed to a nut body 3a and a flange 3b. In the case where the nut body 3a in which a top 7 for circulating a ball is engaged with a top window 8, the top window 8 is also simultaneously molded at the time of the injection molding. |
