The self-aligning roller bearing has two rows of rollers, which mainly bear axial load and radial load at the same time. It has high radial bearing capacity, and is not suitable for working under heavy load or vibration load, but can not bear pure axial load. The outer raceway of this kind of bearing is spherical. It has good alignment performance and can compensate the coaxiality error.

Self aligning roller bearings are divided into symmetric spherical roller and asymmetric spherical roller according to the cross-section shape of roller. Asymmetric self-aligning roller bearing is an early product, mainly for the main engine maintenance service. In the new design of main engine, symmetrical self-aligning roller bearing is seldom used. The internal structure is improved and the parameters are optimized. Compared with the early production of centring roller bearings, they can withstand more axial load. The working temperature of the bearing is low, which can meet the requirements of higher speed. It can be divided into type C and type Ca according to the difference of inner ring and cage. The point of C-type bearing is that the inner ring has no rib and the cage is pressed with steel plate. The point of Ca Ryan bearing is the rib on both sides of inner ring and the solid cage made by automobile. In order to improve the lubrication of the bearing, the user can be provided with a central roller bearing with an outer ring with an annular oil groove and three oil holes, as shown in the rear code / W33 of the bearing.