Due to the press-fitting tool, the oil seal is deformed after press-fitting; ②During the assembly process, the oil seal passes through threads or splines, causing scratches on the lip; ③Due to the low roughness of the oil seal position and excessive press-fitting force, the spring fails or lip flip.
Second, the skeleton reason
Due to material and manufacturing problems of the oil seal spring, its performance failed.The failure mode of the spring is: the spring is too tight or too loose. When the spring is too loose, the spring compression force is small and the sealing effect cannot be achieved. There is an oil spill.
3. Reasons for working medium
The working medium is oil.The choice of oil seal material should consider its compatibility with oil. If the compatibility between the two is poor, lip swelling, hardening, softening, cracking, etc. will occur, and oil leakage will eventually occur.
4. Causes of lip wear
Cleanliness problems: casting sand, machined iron filings, oil impurities, etc., a large amount of oil seal lip parts are accumulated, and abnormal wear occurs during operation; Abnormal wear; ③ The lip of the oil seal is poorly lubricated with lithium-based grease, and dry friction will occur, resulting in abnormal wear.
Five, the reason for the axis
The surface roughness and hardness of the rotating shaft are unreasonable. At present, the automotive industry generally chooses a roughness of not less than 0.8, and high-frequency quenching is used for the parts that cooperate with the oil seal, and the hardness is not lower than HRC55; ②The surface of the rotating shaft has defects, such as: corrosion, scratches Marks, directional knife marks, etc.
