Separated roller for sliding door or window

The utility model relates to a split pulley for sliding doors or windows, which comprises a separable outer shell and an inner shell fixed with a pulley, wherein the edge of the open end of the inner shell is provided with a positioning structure; the corresponding position of the outer shell is also provided with a fixing pin or a slotted hole or a lug boss matched with the positioning structure; the inner shell is arranged inside the outer shell aslant; the outer shell is provided with a height adjusting screw; the front end of the height adjusting screw pushes the declined lateral plane of the inner shell. With simple structure, the split pulley for sliding doors or windows can adjust the height of the pulley and the perpendicularity of the door and the window through adjusting the position of the screw on the declined lateral plane of the inner shell; the adjustment is very convenient and quick; the process production, the assembling and the disassembling are all easy.