The self-aligning roller bearing has double row rollers. The outer ring has one common spherical raceway and the inner ring has two raceways, which are inclined at an angle relative to the bearing axis. This ingenious structure makes it have automatic centering performance, so it is not easy to be affected by the error or shaft bending caused by the angle between the shaft and the bearing housing seat. It is suitable for the occasion of angle error caused by installation error or shaft deflection. The bearing can not only bear the radial load, but also bear the axial load of two-way action.

The inner holes of self-aligning roller bearings are cylindrical and conical, and the taper of conical hole is 1:30 and 1:12. This kind of conical inner hole bearing is equipped with tightening sleeve or withdrawal sleeve, so that the conical inner hole self-aligning ball bearing can be conveniently and quickly assembled on the optical shaft or stepped machine shaft.