Thread Content
This post was last edited by qy576100527 on 2018-10-1 10:11. When an oil seal leak is detected, the location of the leak should be identified first; if it is not caused by an oil seal leak, it is sometimes mistaken for a leak due to reasons other than leakage, such as the presence of grease. The main reasons for oil seal leakage: 1. Deformation of the static sealing surface where the outer edge of the oil seal meets the cavity, due to dimensional tolerances that do not meet standard specifications ； 2. Cracking of the material due to overly harsh operating conditions, especially cracking on the sealing edge of the oil seal ； 3. Increased rubber hardness due to overly harsh operating conditions and incompatibility between the rubber elastomer and the working medium, or the elastomer having too high a hardness ； 4. The sealing medium causes the rubber to swell, reducing its hardness and thus leading to premature aging and wear of the oil seal ； 5. Corrosion from the shaft to the seal lip area will create permanent defects that can affect the sealing performance of the sealing system ； 6. The lubricant fails, causing the system to operate in a dry condition and resulting in rapid wear of the sealing lip ； 7. Comprehensive aging: both the rubber elastomer and the sealing medium age ； 8. The formation of “oil-carbon” dirt at the seal lip causes the seal lip to be lifted, leading to leakage in the sealing system ； 9. The sealing lip of the oil seal no longer follows the vibrations of the shaft surface or the shaft’s runout ； 10. Pollutants permanently embed themselves on the sealing edge, both on the inside and outside of the seal, resulting in premature wear of the shaft surface and the sealing lip ； 11. Irregular assembly procedures lead to damage of the contact surface on the shaft, resulting in premature wear of the sealing lip ； 12. The sealed edge was damaged during storage, transportation, and assembly. When an oil seal leaks, it is necessary to carefully analyze the different types of leakage in order to take appropriate measures. Leakages at different stages of the oil seal should be classified as follows: 1. Water-tight, with no moisture visible on the oil seal ； 2. Moisture: A moisture film appears in the sealed edge area without affecting the sealing performance, but this moisture film does not spread to the back side ； 3. Humid: A layer of moisture spreads to the back side, forming water droplets, but they have not yet started to drip continuously ； 4. Measurable leakage: It is possible to observe tiny streams of liquid flowing out from the back side of the oil seal on the outside of the chamber (WeChat official account: Pump Manager) ； 5. Temporary leaks, short-term failures of the sealing system – for example, those caused by contaminant particles under the sealing edge – can be washed away as long as the device continues to be used ； 6. Significant leakage; temporary leaks occur due to an excessive amount of lubricant applied between the sealing lip and the dust cover lip. The oil that overflows appears as obvious leaks outside the system. Additionally, the cause of leakage is analyzed based on the operating time history of the oil seal; for example, early failure resulting in leakage right from the start of use ； Premature failure resulting in leakage after short use ； After being used for an extended period of time, issues such as leakage and damage occur during operation, as well as leakage and damage at the end of the service life of the oil seal design.