It is comprised of double row combinate with roller and ball in upper and lower layers, inner ring and outer ring, spacer, lubricating and seal fittings. The inner ring and outer ring are in two separate structures and two half rings need to be fixed by joint bolts. Due to the upper and lower rows of steel balls, the bearing can carry radial force, axial force and tilting moment simultaneously. Mostly, the bearing is working under axial force and tilting moment together.