Stepped floating oil seal saves material and labor, the lubrication performance of the working face is good, the heat dissipation effect is good, but the total width of the working face is narrow and the service life is limited. The cross-section of the bell mouth floating oil seal is bell-shaped, and the seal is completed by its bright band. Its advantages are similar to the ladder type, and the disadvantages are also the same, but the difference is that the bell mouth type floating oil seal is slightly wider than the ladder type, so the service life is also relatively Be longer. The advantage of the wide spherical oil seal is that the total width of the working face is large and the service life is long, but the cost is higher than the stepped and bell mouth.