According to the structure, the track roller can be divided into single flange and double flange, which adopt sliding bearings and rolling shafts. The supporting wheel flanges are all quenched, and their hardness reaches 355-440 HB. In the excavator and bulldozer frame, especially when the partition is installed to improve the rigidity, some cavities formed are easy to be blocked by soil and hinder the rotation of the roller; when running on soaked soil, it is also easy to block the roller. Therefore, some crawler bulldozers are equipped with stiffened roller guards on the outside of the trolley frame. The supporting roller is mainly composed of shell, bushing bronze, collar, seal, lock pin, o-ring, plug, shaft,