Damage, Cause, Remedy

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

PROBLEM	DAMAGE	CAUSE	REMEDY
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
	Flaking at rolling element pitch on raceways	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
		Corrosion
	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
	Indentations on raceway at rolling element pitch	Excessive static load	Check static load
	Overrolling	Ingress of foreign matter	Ensure cleanliness of components and integrity of seals
Pick-up	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
	Rolling element fracture	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
Skidding	Scoring of raceway and rolling element surfaces	High start-up acceleration	Control acceleration
Abrasion	Extreme abrasion of raceway,rolling element and cage	Ingress of foreign matter	Improve sealing Improve lubrication
		Corrosion
		Poor lubrication
	Creep	Loose fit	Correct tolerances and fitting
	Creep	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
	False brinelling	Small oscillations in application
Corrosion	Rust inside bearing	Poor storage	Careful storage and handling
	Rust inside bearing	Condensation	Careful storage and handling
	Rust on fitting surface	Fretting	Increase interference fit
	Rust on fitting surface	Fluctuating load	Use oil as lubricant
	Corrosion	Ingress of acid, alkali or gas	Check sealing
	Corrosion	Chemical reaction with lubricant	Use correct lubricant