Timken Industrial Seal Catalog

Oil Seals Appendix D – Failure Analysis
Fractured Carrier Spring
Problem
Ineffective sealing due
to distortion or cracking
of the carrier spring
Potential Cause Potential Solution
• Improper installation • Change installation
technique to
prevent damage
• Excessive load • Do not allow seal to carry
the weight of the shaft
Excessive Leakage (Shaft/Seal Element)
Problem
Leakage occurs between shaft and seal lip
Potential Cause Potential Solution
• Incorrect seal/shaft size • Use correct seal size
• Rough surface finish • Refinish shaft surface
on shaft to seal specifications
• Too much lubricant used • Reduce amount of
during installation installation lubricant
• Shaft machined lead • Refinish shaft surface
(spiral grooves) to seal specifications
• Cocked seal installation • Install seal squarely
into housing bore
• Excessive shaft • Move seal closer to
movement (TIR) bearing
• Previously mentioned • Reference previously
failure modes mentioned sources/
solutions
Excessive Leakage (Bore/Seal Case)
Problem
Leakage occurs between bore and seal case
Potential Cause Potential Solution
• Incorrect seal/bore size • Use correct seal size
• Rough surface finish • Refinish bore surface
on bore to seal specifications
• Use of lubricant during • Do not use lubricant
installation during installation (not
recommended for the
bore and seal case)
• Cocked seal installation • Install seal squarely into
housing bore
Seal Damage Analysis – Appendix D Oil Seals
Excessive Seal
Element Wear
Problem
Wider than normal wear
pattern on the surface of
seal element
Potential Cause Potential Solution
• Excessive internal • Clean drain ports and
pressure chamber vents or upgrade
to seal with higher
pressure capabilities
• High misalignment/ • Upgrade to seal with
runout higher misalignment/
runout capabilities
• Rough surface finish • Refinish surface of shaft
on shaft to seal specifications
• Insufficient lubrication • Properly lubricate the seal
• Extended seal service • Upgrade to extended
service element material
or change maintenance
schedule to accommodate
new seal life requirements
• Oversized shaft • Use proper seal size
Rolled Seal Element
Problem
Seal was rolled
Potential Cause Potential Solution
• Damage during • Change installation techinstallation
nique or use proper tools
to prevent seal damage
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