Used in heavy, medium radial and axial loads (bidirectional, medium-speed, self-aligning performance requirements (is) very high degree of coaxial occasion. 1, carrying capacity, 2, the main radial load, can withstand the axial load, but unable to bear pure axial load, 3, self-aligning performance is good, can compensate the coaxial tolerance of error, 4, speed is low.