Taper roller bearings can be separated by the inner circle roller, keep frame together components and outer ring can be installed separately. Roller and groove in the fixed line contact contact can reduce stress concentration. Taper roller bearings can withstand the big radial direction load and the axial load. Due to the circular cone roller bearings can only transfer one-way axial load, therefore, to transfer the opposite direction of the axial load will need another with the installation of symmetric circular cone roller bearings