Excavators are used to excavate materials and transport them to the storage yard. As one of the most important construction machinery, excavator improves project efficiency and saves labor cost. IBC bearing group provides customized and precision bearings for mining machinery manufacturers. At present, it mainly produces NN series. The double row cylindrical roller is composed of inner ring, outer ring, double row cylindrical roller and cage. This kind of bearing is used in the front end of the spindle of NC lathe. It is the most important precision part of this type of lathe.