(1) Choose appropriate sealing material and hydraulic oil, as well as adaptability to working temperature and compatibility with oil.
(2) The geometric position accuracy (concentricity) of the sliding parts relative to the seal is high, and the material is good (such as hard chrome plating) and the surface roughness is fine, which can extend the service life.
① For the oil seals used in hydraulic pumps and motor shaft necks, it is not only required that the roughness of the sliding surface be within 0.25m Ra, but also that the surface be plated with hard chromium. In specific use, the radial spring force of the oil seal lip needs to be adjusted appropriately according to the specific situation to make it moderately tight. In addition, a mounting sleeve or thin gasket should be used to protect the sealing ring during installation to prevent the lip from curling or twisting, causing the spring to slide out.
② The commonly used rolling processing method for the inner surface of hydraulic cylinder barrel not only improves the surface roughness, but also conducts cold work hardening treatment on its surface, which is beneficial for extending the service life of the sealing ring. In addition, the pressure used, the length and type of sliding surface also have a significant impact on the service life. Therefore, the "scheduled inspection" time should be determined based on these conditions.
③ Require good lubrication of the sealing surface to prevent dirt from entering. It is also necessary to use oil that meets the prescribed cleanliness level and use the correct installation method.