Bearing maintenance and inspection stationary machines
When inspecting a bearing during periodic inspection of equipment, operating inspections, or replacement of adjacent parts, determine the condition of the bearing and if its continued service is advisable.
 
A record should be kept of the inspection and external appearance of dismounted bearings. After taking a grease sample and measuring the quantity of residual grease, the bearing should be cleaned. Also, determine whether abnormalities and damage exist in the cage, fitting surfaces, rolling element surfaces and raceway surfaces. Observation of running traces on the raceway surface.

When evaluating whether a bearing can be re-used or not, the following points need to be considered: degree of bearing damage, machine performance, critical nature of the application, operating conditions, inspection interval. If the inspection reveals bearing damage or abnormalities, then try to confirm the cause and determine a countermeasure and then carry out the countermeasure. If your inspection discovers any of the following kinds of damage, which would prevent the bearing from being reused, then the bearing must be replaced with a new one.
 
Typical observation for the following:
  • Cracks or chipping in the cage, rolling elements,or raceway ring.
  • Flaking in the rolling elements or raceway ring.
  • Notable scoring on the rolling elements, rib face (collar),or raceway surface.
  • Notable wear on the cage or loose rivets.
  • Flaws or rust on the rolling elements or raceway surface.
  • Notable dents on the rolling elements or raceway surface.
  • Notable creep of the outer ring outside surface or inner ring bore.
  • Discoloration due to heating.
  • Serious damage on shield or seal of grease packed bearings
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