English: Self-aligning ball bearings have two rows of balls and a common sphered raceway in the outer ring. The bearings are insensitive to angular misalignment of the shaft relative to the housing. This type of ball bearing is recommended when alignment of the shaft and housing is difficult and the shaft may flex. They are designed to work in applications where severe misalignment exists whether from mounting or shaft deflection.It aligns itself correctly with the shaft and assembly without causing undue stress on the rest of the bearing assembly. 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. It generates less friction than any other type of rolling bearing, which enables them to run cooler even at high speeds.