Rolling bearings are designed to perform reliably and reach their intended service life when applied correctly. However, in many cases, they fail earlier than expected due to preventable issues. Common reasons for such failures include incorrect installation, poor handling practices, insufficient or improper lubrication, contamination from external particles, and excessive heat buildup. 

The following sections highlight typical bearing damage scenarios along with practical solutions. Use these examples as a reference when investigating the cause of bearing issues. 

Excessive Preload or Overload

Excessive loads usually cause premature fatigue. The solution is to use a bearing with greater capacity or reduce the load. 

Overheating

Overheating in bearings is often indicated by discolouration of the cage, rolling elements, or raceway rings. This heat exposure can lead to a loss of hardness in the bearing components, ultimately causing premature failure. To prevent this, it’s important to implement proper thermal management, monitor for overloads, and, if necessary, provide additional cooling.

Cage Damage

Incorrect installation or impact from dropping the bearing can lead to damage. Proper handling procedures should be implemented to prevent such issues.

False Brinelling

Elliptical wear marks in the axial direction at each ball position with a bright finish indicate excessive external vibration. The problem is corrected by isolating bearings from external vibration. 

True Brinelling

True brinelling occurs when loads exceed the elastic limits of the ring material. Marks show as indentations in the raceway. This is caused by improper bearing installation. Proper assembly requires professionalism, care, cleanliness, precision, and the correct tools. 

Tight Fits

Discoloured, wide ball path at the bottom of the raceway indicates a tight fit. Where interference fit exceeds the radial clearance, balls will become overloaded. Increased radial clearance or other corrective actions are required.

Improper Fit

Loose fits can cause relative motion between mating parts. If fit is improper, fretting occurs. This refers to wear and sometimes corrosion damage on mounting surfaces. Check recommended fits to avoid this problem.

Peeling

With this type of bearing failure, dull or cloudy spots appear on the surface. From such dull spots, tiny cracks are generated. This is caused due to a thin lubricant film from high loads/low RPM or elevated temperatures. Improvement of the surface finish of the rolling mating or proper lubricant selection is recommended.

Corrosion / Etching

Rusting and pitting caused by moisture or water exposure are red/brown areas on bearing parts. If bearings are used in a challenging environment, solutions like external seals, stainless steel, and surface treatments should be considered.

Foreign Material

Contamination is one of the most common causes of bearing failure. Large particles can get embedded into the soft cage, fine abrasive particle contamination or contamination from other fatigued parts is caused by inadequate sealing or poor maintenance. Proper assembly requires clean work areas, tools and fixtures.

Normal Fatigue Failure

Fatigue failure is the fracture of the running surfaces. This type of failure will always be accompanied by increased vibration. Replacement of the bearing is required or redesign to use a bearing with a longer calculated fatigue life.

Misalignment

Raceway ball tracks that are not parallel to the raceway edges are caused by inaccurate machining or wear of bearing seats. Appropriate corrective actions would be shaft and housing inspection, and using precision grade locknuts.

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