A self-aligning ball bearing is a bearing equipped with spherical balls between the inner ring of two raceways and the outer ring of a spherical raceway.

The curvature center of the outer raceway surface is consistent with the center of the bearing, so it has the same centering function as the automatic centering ball bearing. When the shaft or housing bends, it can be automatically adjusted without increasing the bearing burden. Spherical roller bearings can withstand radial loads and axial loads in two directions. Large radial load capacity, suitable for situations with heavy loads and impact loads. The inner diameter of the bearing is a tapered hole, which can be directly installed. Or use a tightening sleeve or a disassembly cylinder to install it on the cylindrical shaft. The retaining frame uses steel plate stamping retaining frame, polyamide forming retaining frame, and copper alloy car made retaining frame.

Self aligning ball bearings have two structures: cylindrical holes and conical holes, and the material of the cage includes steel plate, synthetic resin, etc. Its characteristic is that the outer raceway is spherical in shape and has automatic centering, which can compensate for the errors caused by different centering and shaft deflection in the centering ball bearing. However, the relative inclination of the inner and outer rings shall not exceed 3 degrees.

It can withstand large radial loads and also withstand certain axial loads. The outer raceway of this type of bearing is spherical, so it has centering performance. When the shaft is bent or tilted under force, and the relative inclination between the inner ring centerline and the outer ring centerline does not exceed 1 °~2.5 °, the bearing can still work.

There are two types of inner holes for self-aligning ball bearings: cylindrical and conical. The taper of the conical inner hole is 1:12 or 1:30. In order to enhance the lubrication performance of the bearing, an annular oil groove and three oil holes are machined on the outer ring of the bearing.