The internal structure of cylindrical roller bearing adopts parallel arrangement of rollers, and there are interval retainers or isolation blocks between rollers, which can prevent the inclination of rollers or mutual friction between rollers, and effectively prevent the increase of rotation torque. The cylindrical roller and raceway are linear contact bearings. Large load capacity, mainly bearing radial load. The friction between the rolling element and the ring flange is small, so it is suitable for high-speed rotation. According to whether the ring has rib or not, it can be divided into single row cylindrical roller bearings such as Nu, NJ, NUP, N and NF, and double row cylindrical roller bearings such as NNU and NN.