Silicon nitride ceramic sealing ring is used to prevent the leakage of fluid or solid particles between adjacent critical interfaces and to prevent impurities or residues from the outside, such as invisible dust and moisture from the parts and components of mechanical equipment. Below we sum up what should be noted for using silicon nitride ceramic sealing ring.
1. Select appropriate sealing materials and hydraulic oil, and pay attention to the temperature environment and oil compatibility.
2. The concentricity of the geometric position of the parts relatively sliding to the seal, good material quality and finer surface furnishing can extend the lifetime.
3. The oil seal used for the hydraulic pump and motor not only requires the furnishing of the sliding surface to be within Ra 0.25m, but also requires hard chrome plating on the surface. Meanwhile the lip diameter of the oil seal needs to be properly adjusted accordingly. The spring force makes it moderately tight, and the sleeve or gasket is used to protect the sealing ring during installation so that the lip does not curl or twist, causing the spring to slide out.
4. The inner surface of cylinder is usually produced by processed rolling, which not only improves the surface furnishing, but also makes the surface cold hardened, which helps extend the seal ring’s lifetime. In addition, the pressure, the length and type of sliding surface have a great impact on the lifetime. Therefore, the "inspection" frequency should be determined according to these conditions.
5. The sealing surface should be in good lubrication condition to prevent dirt from entering. Using the oil clean enough and correct installation method are required.
