Roller-type linear sliding block

A roller-type linear sliding block, comprising a base block, two circulation-guiding blocks coupled to two opposing ends of the base block and a plurality of rollers received in the base block, the base block having a sliding groove corresponding to a linear sliding rail and a pair of load-bearing tracks formed at two sides of the sliding groove;

• the base block being formed with a cover member by molding, the cover member being formed with a pair of non-load tracks beside the pair of load-bearing tracks and a pair of retainers at two sides of each of the load-bearing tracks;
• each of the circulation-guiding blocks comprising an inner circulation member which is integrally formed with an end of the cover member of the base block, a middle spacer coupled to the inner circulation member and an outer circulation member, the middle spacer and the outer circulation member being connected to an outer side of the inner circulation member in series, the inner circulation member cooperating with the middle spacer to form a first circulation track, the middle spacer cooperating with the outer circulation member to form a second circulation track, the first circulation track and the second circulation track being interlaced.