Damage, Cause, Remedy

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

FlakingFlaking on one side of entire racewayExcessive axial load by poor fitting or linear expansionUse clearance fit on non-rotating bearing outer ring
Flaking at rolling element pitch on racewaysRaceways brinelled during fittingCareful fitting
Corrosion during down timeApply corrosion protective
Premature flaking of raceway and rolling element surfacesExcessive load

Check fitting

Correct clearance

Use correct lubricant quantity

Clearance too small
Poor lubrication
Poor fitting
Flaking across the racewayPoor fitting and eccentricityFitting and centering with care
Shaft deflectionUse bearing with larger internal clearance
Geometric inaccuracy of shaft and housingShaft and abutments to be square
Flaking around raceway
Poor housing accuracyCheck geometric accuracy of housing bore
IndentationsIndentations on raceway at rolling element pitchShock loads during fitting or poor handlingHandling with care
Excessive static loadCheck static load
OverrollingIngress of foreign matterEnsure cleanliness of components and integrity of seals

Discolouration of raceway and rolling element surface

Softening of surfaces

Excessive loadCheck fitting
Clearance too smallCorrect clearance
Poor lubricationUse correct lubricant quantity
Poor fittingCheck fitting method
Electrical erosionRaceway eroded at regular intervalsArcing due to bearing conducting electricity

Ground the bearing

Insulate the bearing

FractureRaceway surface fractureExcessive shock loadsCorrect loading
High interference fitProper fitting
Increase of flaking and softening;welding of inner ring to shaftEnsure correct geometry of shaft and housing
Corner fillet radii too largeCorrect fillet radii
Rolling element fracture Excessive shock loadsCorrect loading
Excessive internal clearanceCheck fitting and clearance
Cage fractureTilting momentsFit with care
High speed impulse and high accelerationEnsure uniform rotation
Incorrect lubricationCheck lubricant and lubrication method
Ingress of foreign matter in bearingImprove sealing
SkiddingScoring of raceway and rolling element surfacesHard greaseUse soft grease
High start-up accelerationControl acceleration
AbrasionExtreme abrasion of raceway,rolling element and cageIngress of foreign matterImprove sealing

Improve lubrication
Poor lubrication
CreepLoose fitCorrect tolerances and fitting
Incorrectly fixedCorrect fixing
Fretting corrosionSmall movements between surfacesIncrease interference fit
False brinellingVibration in non-rotating bearingInsulate bearing from vibration

Use oil as lubricant

Apply preload
Small oscillations in application
CorrosionRust inside bearingPoor storageCareful storage and handling
Rust on fitting surfaceFrettingIncrease interference fit
Fluctuating loadUse oil as lubricant
CorrosionIngress of acid, alkali or gasCheck sealing
Chemical reaction with lubricantUse correct lubricant