Tapered roller bearings belong to separated bearings, the inner and outer rings of the bearings have tapered raceways. Roller is cylindrical, roller and raceway for linear contact, can bear heavy radial and axial joint the larger the contact angle, the higher the axial load carrying capacity; conversely, the smaller the contact angle, the higher the axial load carrying capacity. the smaller the contact angle, the lower the axial load carrying capacity, tapered roller bearing contact roller number, can be divided into single the number of contact rollers can be divided into single row, double row and four rows of tapered roller bearings and other different forms, the bearings are also more practical inch series products.