Spherical Roller Bearings
Spherical roller bearings have barrel-shaped rollers-between the inner ring, which has two raceways, and the outer ring which has one spherical raceway. Since the center of curvature of the outer ring raceway surface coincides with the bearing axis, they are self aligning in a manner similar to that of self-aligning ball bearings. Therefore, if there is deflection of the shaft or housing or misalignment of their axis, it is automatically corrected so excessive force is not applied to the bearings. Spherical roller bearings can take, not only heavy radial loads, but also some axial loads in either direction. They have excellent radial load carrying capacity and are suitable for use where there are heavy or impact loads. Some bearings have tapered bores and can be mounted directly on tapered shafts or cylindrical shafts using adapters or withdrawal sleeves. Pressed steel and machined brass cages are generally used.
In spherical bearings the rollers are guided by the raceways, the cage and a non-integral guide ring which is positioned between the two rows of rollers. These bearings operate at lower temperatures or can accommodate heavier axial loads. To facilitate efficient lubrication, spherical roller bearings feature an annular groove and three lubrication holes in the outer ring as standard. The spherical roller bearings are manufactured to normal tolerances and have normal internal radial clearance. These bearings are also available with internal radial clearance C3 (greater than normal).