Rolling Bearing Damage 

The life of a rolling bearing depends on the total number of stress cycles and the loads incurred by rolling elements and raceways. The standardized calculation method for dynamically stressed bearings is based on material fatigue (pitting) causing the damage. Normal fatigue manifests itself by flaking or spalling of the rolling surfaces. An increasing local stress may result in fracture of the ring. If the bearing fails earlier than predicted by the life calculation, it should be checked for overloading. With this failure cause excluded, faulty mounting or poor maintenance or wear might be the cause for the damage. The following pages describe some of the more common forms of bearing damage and their causes.

Corrosion Corrosion in rolling bearings may occur in various forms and have different causes. The damage shows in an uneven and loud running noise. The rust abraded by the rolling elements causes wear.

Possible causes: 

Inadequate sealing against moisture, 

Ccid fumes, 

Lubricants containing acids, 

Condensation, 

unsuitable storage of the rolling bearings in the warehouse. 

False brinelling is identified by marks in the raceways at rolling element spacing. In contrast to the rolling element indentations caused by incorrect mounting, they have no raised edges. The increased number of indentations shown in is a result of occasional turning of the bearing. 

False brinelling is caused by vibrations in the contact areas of parts while these are stationary, resulting in wear. Susceptible to such dam age are machines which are subjected to vibrations while stationary or during transportation. 

Possible remedy: Securing by wedges or similar means for transportation or keeping the bearing in rotation (e. g. on ships). Fretting corrosion, however, occurs at the fitting surfaces, i. e. in the bearing bore or at the bearing outside diameter. It is caused by relatively loose fits or too soft mating components. Minute motions (micro-slipping) in the fitting joint may cause heavy wear resulting in an impeded floating bearing function or fracture of the shaft due to notch stresses. Possible remedy: Tight bearing fits or reinforcement of mating structure.

References;

CATALOGO NO. Publ. No. WL 80 100/3 EA,Mounting and DismountingFAG Rolling Bearings,,» Germany, 2004.