Inner ring and outer ring of taper roller bearings has conical raceway. Tapered roller is set between raceway. If tapered face is extended, they will finally gather at one point of bearing axis.Taper roller bearings are mainly used for bearing radial and axial load joint with radial load as main load. Axial bearing capacity of bearing is decided by contact angle. The bigger angle value, the axial bearing capacity is bigger.Double row taper roller bearings mainly have two structural types,TDO Type and TDI Type.