Tapered roller bearings: they can bear both radial and axial loads. Double row tapered roller bearings can bear bidirectional axial loads.Because of the sliding friction between the large end of the taper roller and the inner ring baffle, the ultimate speed is usually lower than that of the cylindrical roller bearing of the same size.Hollow tapered roller bearings allow the roller to be cooled with oil, reducing the temperature rise and thus increasing the allowable speed.However, this kind of bearing manufacturing process is complex and requires a high degree of lubrication system for machine tools.