Cylindrical roller bearing is a kind of rolling bearing with its rolling element is cylindrical roller, which divided into single-row cylindrical roller bearing and double-row cylindrical roller bearing. Generally speaking, single-row cylindrical roller bearing is used to bear radial load, higher radial load compared with deep groove ball bearing with the same size, meanwhile impact resistance and rigidity. However, it could not bear axial load, such kind of bearing is separable, thus mounting & dismounting is much more convenient, on the other hand, the axial lead for inner & outer ring is not allowed to tilted when installation, the processing precision and installation is higher for shaft and shell hole. The structure for double-row cylindrical roller bearing is impact with small deformation when withstanding radial load, particularly suitable to supplying machine tool spindle, this kind of bearing can separately install inner assembly and outer ring, but do not limit axial displacement of shaft or housing, meanwhile it could not bear axial load.