Patent ID: 8640564

Claim:
A ball screw having circulation elements, comprising: a screw, being formed with a spiral rolling trough at an outer edge thereof; a cap nut, being formed with a through hole for the screw to insert through, an inner edge of the through hole formed with a rolling trench relative to the rolling trough, the rolling trench and the rolling trough forming a loading path, the loading path having a lead angle, and the cap nut having a circulation hole, being formed through two ends of the cap nut along an axial direction, and two mounting troughs, being respectively formed at two ends of the circulation hole and connecting with the rolling trench; two circulation elements, being formed at the mounting troughs, respectively, each of the circulation elements being formed with a circulation passage, two ends of the circulation passage connecting to the loading path and the circulation hole to form a circulation path; and a plurality of rolling elements, being formed at the circulation path; wherein each of the mounting troughs is formed with an inclined plane, the inclined plane is approximately parallel to a lead angle of the loading path, each of the circulation elements is formed with a mating surface, the mating surface of each circulation element is formed relatively to the inclined plane of the corresponding mounting through, and wherein each of the mounting troughs is further formed with a first leaning surface and a second leaning surface respectively extending from two sides of the inclined plane, and a normal direction of the first leaning surface and the second leaning surface is parallel to the axial direction of the screw.