Patent ID: 7934870

Claim:
A circulating structure for a linear guideway being arranged in a circulating assembly of the linear guideway, the linear guideway comprising: a slide rail being provided with at least one rolling groove at each of two opposite sides thereof; a slide block being movably mounted on the slide rail and provided with rolling channels opposite to the rolling grooves of the slide rail, the rolling channels and the rolling grooves defining a loaded path including two first guiding grooves, the slide block being further provided with a circulating hole which doesn't intersect with the rolling channels, the circulating hole being provided with two second guiding grooves; two circulating assemblies being respectively arranged at two opposite ends of the slide block, each circulating assembly being provided with a circulating channel, both ends of the circulating channel of each circulating assembly being linked up with the loaded path and the circulating hole to define a closed circulating path, the circulating channel of each circulating assembly being provided with two third guiding grooves, which are linked up with the second guiding grooves and the first guiding grooves to define a closed guiding groove system with a constant width; and plural rolling elements being installed in a rolling element chain to form a rolling element system, the rolling element chain being provided for separating the rolling elements from one another, the rolling element chain including at least one spacer and one linking portion, the rolling element system being arranged in the loaded path, the circulating hole and the circulating channels, the linking portion of the rolling element chain being arranged in the guiding groove system, a width of the guiding groove system being larger than a width of the linking portion, a return route along which the linking portion circulates overlapping with a center line of each of the third guiding grooves; wherein: the rolling elements within the respective circulating channels include a return radius of curvature R, a rolling element return center O, a part of the rolling element chain within the circulating channel includes a return radius of curvature Rc of the linking portion of the rolling element chain, the center line Y of each of the third guiding grooves includes two end points at two ends of the return route, between the two end points of the center line Y of each of the third guiding grooves and the rolling element center O are the rolling element return radius of curvature R and the return radius of curvature Rc of the linking portion of the rolling element chain, respectively; the return radius of curvature Rc of the linking portion of the rolling element chain, the rolling element return radius of curvature R, a diameter D of the rolling elements and a closest distance H between two rolling elements satisfy the relation: R C =√{square root over ( R 2 −( D/ 2 +H/ 2) 2 )}.