Lip seal


The seal is shown in the top half of the drawing. It is a spring loaded elastomer seal commonly used to seal bearings.

These seals have a useful life of less than 2000 hours (83 days) and they will damage the shaft under the rubber lip. Please see “fretting.”

This is the standard method used by most manufacturers to seal the lubricant in a bearing. A better choice would be:

  • labyrinth seal shown in the bottom half or
  • A bearing face seal

Grease seals are notorious for damaging the rotating shaft under the lip. See “fretting” for an explanation of why this happens.

A positive face seal like the type used in the water pump of your car would be the best. Check with your distributor for the availability of face seals for your application.


  • On February 16, 2018