| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw with a nut having a projection projecting from an end surface in an axial direction on a part in a circumferential direction, in which the center of gravity of the nut is brought near a rotation center line of the nut without forming a thinning hole machining part on the nut.SOLUTION: In a ball screw, a recess made by a top 3 disposed at the same position as a projection 13 in the circumferential direction of the nut 1 (namely, the structure of the recess constituting a ball return passage) eliminates or reduces a deviation of the center of gravity of the nut 1 from a rotation center line due to the projection 13. |
