Bearing re-lubrication intervals

 Lubricating greases slowly degrade and therefore have a limited life. Rolling bearings have to be relubricated if:

  • The grease life is shorter than the specified bearing life.
  • The grease becomes contaminated.

Grease life depends mainly on:

  • Bearing type and size
  • Grease type
  • Speed
  • Load ratio C/P
  • Operating temperature

Relubrication should occur frequently enough to avoid grease deterioration having an adverse effect on the bearing life. Therefore, the SKF relubrication interval, tf, is defined as the time at the end of which there is only a 1% probability that the bearing will fail because of grease degradation. This represents the L1 grease life. To compare grease life with the specified bearing life, you can use the L10 grease life, which represents a 10% probability failure because of grease degradation. You can find information about the grease life of sealed bearings in the relevant product sections. The L10 grease life can also be estimated by multiplying the relubrication interval (L1 grease life) by a factor of 2.7.





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