Self-aligning 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 coinc-ides with the bearing axis, they are self-aligning in a manner similar to that of self-aligning ball bearings. Therefore,if there is reflection of the shaft or housing or misalignment of their axies, it is automatically corrected so excessiveforce is not applied to the bearings.Self-aligning 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 and maybe mounted directly on tapered shafts or cylindrical shafts using adapters or withdrawal sleeves.Pressed steel and machined brass cages are used.