Step-type outer-diameter self-sealing double-row tapered roller bearing

The utility model belongs to the technical field of manufacturing of rail transit bearings, and particularly relates to a stepped outer-diameter self-sealing double-row tapered roller bearing which comprises an inner ring, an outer ring, a retainer and double-row rollers, and the double-row rollers are retained between the inner ring and the outer ring through the retainer. The two sides of the inner wall of the outer ring are each provided with a sealing groove used for assembling a sealing assembly, the two sides of the outer wall of the outer ring are each provided with a groove concave inwards in the radial direction, the groove in each side corresponds to the corresponding sealing groove, the axial length of each groove is larger than the axial length from the corresponding sealing groove to the end face of the outer ring, and a center part is arranged between the grooves in the two sides. The grooves on the two sides are connected with the central part to form a complete outer wall of the outer ring, an