Patent ID: 7810406

Claim:
A circulating assembly for a ball screw being disposed on a nut having a circulating hole for guiding balls between the nut and the screw into and out of the circulating hole, the circulating assembly comprising a cassette and a separator; wherein: the cassette is formed with a main return path for connecting to the circulating hole of the nut, a fitting hole extends outward from the main return path; and the separator is inserted in the fitting hole of the cassette, a sub-return path is formed at a front end of the separator and is connected to the main return path, and the sub-return path cooperates with the main return path to guide the circulation of the balls; the nut including the circulating hole and a helical groove winding around inner surface of the nut, a recess being formed in an end surface of the nut and located correspondingly to the helical groove and the circulating hole; the cassette further includes a nail portion inserted in the helical groove of the nut, the main return path is connected between the circulating hole of the nut and the helical groove, the fitting hole is a through hole extending outward from the main return path; and the separator includes an inserting rod to be inserted in the fitting hole of the cassette, and the sub-return path is located at a front end of the inserting rod.