Patent ID: 10274061

Abstract:
Provided is a ball screw capable of reducing unevenness of load distribution of balls and extending a service life of the ball screw. In the ball screw, one end part 6 of a nut 2 on a flange 2-2 side is closer to an end 9 of a screw shaft 1 on a fixed side than the other end part 7 of the nut 2 on a side opposite the flange 2-2 is, two or more circulation paths 5a to 5c are arranged in an axial direction of the nut 2, and a diameter of a ball 3a in the circulation path 5a closest to the flange 2-2 of the nut 2 is smaller than a diameter of a ball 3c in the circulation path 5c remotest from the flange 2-2 of the nut 2.