Spherical roller bearings have two raceways on inne ring,spherical raceway on outer ring and spherical rollers. Since the center of the are raceway on the outer ring is the same as the center of the whole bearing arrangement, so these bearings are self-aligned and automatically adjust the eccentricity arose from the error of mounting bearings in housings or from the bending of the shafts. The bearings can normally run when the acute angle between the centric lines of outer ring and inner ring ranges within 1° -2.5° The bearings can accommodate radial load and axial load in double directions. The especial radial load carrying capability makes these bearing suitable for heavy load and shock load carrying.