A spherical plain bearing is a bearing that permits angular rotation about a central point in two orthogonal directions.
The outer surface of the inner ring and the inner surface of the outer ring are spherical and are collectively considered the raceway and they slide against each other.
The centre point of the sphere in the outer ring raceway is at the bearing axis. Therefore, the bearings are self-aligning and insensitive to misalignment of the shaft relative to the housing, which can be caused, for example, by shaft deflection.
Spherical roller bearings are designed to accommodate heavy radial loads, as well as heavy axial loads in both directions.
