Spherical roller bearings have two rows of rollers, which mainly bear radial loads and can also withstand axial loads in either direction. With the high capacity of radial load, it is especially suitable for work under heavy load or vibration load but can not bear pure axial load. The raceway of the outer ring of this type of bearing is spherical, so its self-aligning performance is good and can compensate the error of coaxiality.