Self-aligning ball bearings

The outer ring raceway of self-aligning ball bearings forms a spherical surface whose center is common to the bearing center. The inner ring of the bearing has two raceways. The balls, cage, and inner ring of these bearings are capable of a shifting in order to compensate for a certain degree of misalignment with the outer rings. As a result, the bearing is

able to align itself and compensate for shaft/ housing  finishing unevenness, bearing fitting error, and other sources of misalignment. However, since axial load capacity is limited, self-aligning ball bearings are not suitable for applications with heavy axial loads. If an adapter is used on the tapered bore of the inner diameter, installation and disassembly are much simpler and for this reason adapters are often used on equipment with drive shafts.