Self-aligning Ball Bearings

Self-aligning ball bearings are double row, self-retaining units comprising outer rings with a concave raceway, inner rings with a cylindrical or tapered bore and ball and cage assemblies. The bearings are available in open and sealed designs.

They are recommended for applications where aligning the shaft and housing is difficult or where the shaft may bend, such as transmission shafts. The outer ring has a spherical raceway and its center of curvature coincides with that of the bearing, allowing the axis of the inner ring, balls, and cage to rotate freely around the bearing center. Pressed steel cages are typically used for this type.

Since they have a small contact angle, self-aligning ball bearings have low axial load capacity. Permissible dynamic misalignment is approximately 0.07 to 0.12 radian (4 to 7 degrees) under normal loads; however, such angles may not be allowable depending on the surrounding structure.

Features and Benefits

  • Accommodate static and dynamic misalignment
    The bearings are self-aligning like spherical roller bearings or CARB bearings.
  • Excellent high-speed performance
    Self-aligning ball bearings generate less friction than any other type of rolling bearing, which enables them to run cooler even at high speeds.
  • Minimum maintenance
    Because of low heat generation, the bearing temperature is lower, leading to extended bearing life and maintenance intervals.
  • Low friction
    Very loose conformity between balls and outer ring keeps friction and frictional heat at low levels.
  • Excellent light load performance
    Self-aligning ball bearings have low minimum load requirements.
  • Low noise
    Self-aligning ball bearings can reduce noise and vibration levels, for example, in fans.