Damage, Cause, Remedy

Incorrect handling of bearing can cause damage and shorten the life. The following shows typical causes and suggested remedies.

Flaking Flaking on one side of entire raceway Excessive axial load by poor fitting or linear expansion Use clearance fit on non-rotating bearing outer ring
Flaking at rolling element pitch on raceways Raceways brinelled during fitting Careful fitting
Corrosion during down time Apply corrosion protective
Premature flaking of raceway and rolling element surfaces Excessive load

Check fitting

Correct clearance

Use correct lubricant quantity

Clearance too small
Poor lubrication
Poor fitting
Flaking across the raceway Poor fitting and eccentricity Fitting and centering with care
Shaft deflection Use bearing with larger internal clearance
Geometric inaccuracy of shaft and housing Shaft and abutments to be square
Flaking around raceway
Poor housing accuracy Check geometric accuracy of housing bore
Indentations Indentations on raceway at rolling element pitch Shock loads during fitting or poor handling Handling with care
Excessive static load Check static load
Overrolling Ingress of foreign matter Ensure cleanliness of components and integrity of seals

Discolouration of raceway and rolling element surface

Softening of surfaces

Excessive load Check fitting
Clearance too small Correct clearance
Poor lubrication Use correct lubricant quantity
Poor fitting Check fitting method
Electrical erosion Raceway eroded at regular intervals Arcing due to bearing conducting electricity

Ground the bearing

Insulate the bearing

Fracture Raceway surface fracture Excessive shock loads Correct loading
High interference fit Proper fitting
Increase of flaking and softening;welding of inner ring to shaft Ensure correct geometry of shaft and housing
Corner fillet radii too large Correct fillet radii
Rolling element fracture Excessive shock loads Correct loading
Excessive internal clearance Check fitting and clearance
Cage fracture Tilting moments Fit with care
High speed impulse and high acceleration Ensure uniform rotation
Incorrect lubrication Check lubricant and lubrication method
Ingress of foreign matter in bearing Improve sealing
Skidding Scoring of raceway and rolling element surfaces Hard grease Use soft grease
High start-up acceleration Control acceleration
Abrasion Extreme abrasion of raceway,rolling element and cage Ingress of foreign matter Improve sealing

Improve lubrication
Poor lubrication
Creep Loose fit Correct tolerances and fitting
Incorrectly fixed Correct fixing
Fretting corrosion Small movements between surfaces Increase interference fit
False brinelling Vibration in non-rotating bearing Insulate bearing from vibration

Use oil as lubricant

Apply preload
Small oscillations in application
Corrosion Rust inside bearing Poor storage Careful storage and handling
Rust on fitting surface Fretting Increase interference fit
Fluctuating load Use oil as lubricant
Corrosion Ingress of acid, alkali or gas Check sealing
Chemical reaction with lubricant Use correct lubricant