Among the most common causes of oil seal failure are:
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Regular maintenance and inspection of the oil seal are essential to ensure its continued effectiveness. Any signs of wear or damage should be addressed promptly to prevent oil leaks and potential damage to the machinery or equipment.
Figure 6: Recommended housing bore chamfers (shouldered bore)
: spiral shaped, ensures constant pressure and maintains the optimal force to the shaft.
Case study 2: Silicone oil leakage
First, an elastomer, most often nitrile, is vulcanised to a metal ring. This creates a stiffening effect that includes a specialised metal tension spring directly behind the sealing lip, keeping the oil seal firmly in place against the moving part.
Car Oil Seal Types and Applications


Standard 3760/3761
In addition to size and material, the design and construction of the oil seal are also crucial factors to consider. The 65x90x10 oil seal is typically constructed with a metal casing, a rubber sealing lip, and a spring for added tension. This design helps to create a tight seal and prevent oil from leaking out, even under high pressures and temperatures.
oil seal 65x90x10


Out-gassing
DIN


Other important factors are ensuring the hardness and roughness of the shaft are correct. A shaft hardness of HRC 45 is recommended for a rubber sealing lip, with a roughness of Ra 0.4-0.8. A higher shaft hardness of HRC 60 and shaft roughness of Ra 0.1-0.4 is recommended for a PTFE lip.
Jiri George Drobny, in Fluoroelastomers Handbook (Second Edition), 2016