② The floating seal ring must be made of the same material, and the hardness of the sealing end surface is 60～72HRC. If the material and hardness are inconsistent, the oil seal will fail due to uneven wear.

③ The flatness of the sealing end face of the floating seal ring The sealing of the floating oil seal is ensured by the rigid contact of the sealing end face of the floating seal ring. Because the two floating seal rings rotate relative to each other, the unevenness of the seal end face cannot be filled by elastic and plastic deformation; The flatness accuracy is high, and a thin and complete oil film can be formed on the end face, so that the sealing end faces of the two floating seal rings are in a suspended state, reducing wear.