Flaking occurs as a
result of normal fatigue, i.e. the bearing has reached the end of its normal life span.
However, this is not the commonest cause of bearing failure. The flaking detected in
bearings can generally be attributed to other factors. If the flaking is discovered at an
early stage, when the damage is not too extensive, it is frequently possible to diagnose
its cause and take the requisite action to prevent a recurrence of the trouble. The path
pattern of the bearing may prove to be useful, see path
patterns and their interpretation.
Fig 1 - Flaked cone and rollers of taper roller bearing. Heavy loading and inadequate lubrication are the causes of this damage.
Figure 2 - Outer ring of a self-aligning ball bearing that has been driven too far up its tapered seating. The bearing had only performed a few revolutions when the damage was detected. Flaking would soon have occurred if the bearing had been put into service.
Flaking caused by oval compression
Figure 3 - Flaking in the outer ring of spherical roller bearing that has been mounted in a housing with oval bore.
Flaking caused by axial compression