Cylindrical rollers and raceways are line contact bearings. Load capacity, mainly bear radial load. The friction between the rolling element and the rib of the ferrule is small, which is suitable for high-speed rotation. According to whether the ring has ribs, it can be divided into single row cylindrical roller bearings such as NU, NJ, NUP, N, NF, and double row cylindrical roller bearings such as NNU and NN. The bearing has a detachable inner ring and outer ring.