This type of ball bearing is recommended when alignment of the shaft and housing is difficult and the shaft may flex. The outer ring has a spherical raceway and its center of curvature coincides with that of the bearing; therefore, the axis of the inner ring, balls and cage can deflect to some extent around the bearing center. Pressed steel cages are usually used. Since the contact angle is small, the axial load capacity is low. The permissible dynamic misalignment is approximately 0.07 to 0.12 radian (4 to 7 degrees) under normal loads.

Self Aligning Ball Bearings Specifications & Standards

• Standard cage types - All bearing series are equipped with a pressed cage, except 2322S, which is equipped with a machined cage.
• Dimensions -The dimensions are as per the ISO recommendations.
• Misalignment - They are designed to adjust to the angular misalignment from one bearing to the other within the permissible limits.
• Tolerance - They are usually meant for normal tolerance but can be enhanced.
• Ball protrusion - Bearings with part numbers listed in the diagram below have balls which protrude slightly from the bearing face. Their degree of protrusion is listed below:

• Allowable misalignment angle - Allowable misalignment under normal loads (loads equivalent to 0.09 Cr): 0.07 rad (4°).This degree of allowable misalignment may be limited by the design of structures around the bearing.