Most of cylindrical roller bearings are separable. This make it very convenient to mount and dismount. Cylindrical roller bearings can carry heavier radial load, and are suitable to be used in the condition of high speed. This type of bearings can allow a small angular error between inner axes and outer axes in the range of 2′ ～ 4′. Therefore, it requires higher machining precision on shaft and housing; otherwise, asymmetrical load and stress would be focused at the position of raceway. However, this situation can be improved by correcting the contacted generatrix of rollers or raceways. According to different rows, cylindrical roller bearings are divided into single row, double-row, and multi-row cylindrical rollers. These differences are also displayed on the design of flange position.