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Table 12 Bearing Troubles and Causes
Phenomena
Condition
Cause
Remedy
Flaking
①
Flaking of rolling element
②
Local flaking of raceway track
③
Flaking over entire circumference
of raceway track
④
Flaking of place opposite to raceway
track
⑤
Flaking over entire circumference
off center of raceway track
⑥
Flaking diagonally crossing
raceway track
⑦
Rolling element pitch-like flaking
on raceway track
①
Excessive interference
②
Wrong selection of clearance
③
Operation clearance minus
④
Expansion due to temperature
Inclusion of dust, foreign matter or
rusting/dent
①
Elliptic distortion of shaft or bearing
housing
②
Faulty tightening
③
Faulty machining accuracy
④
Secular change, abnormal thrust load
①
Warp of shaft
②
Oblique installation of inner/outer rings
①
Vibration during stoppage
②
Rusting
①
Caution in assembling or making
shaft/bearing housing
②
Review of clearance
③
Handling care in assembling
④
Investigation of service condition
Investigation of machining accuracy of
shaft/bearing housing, investigation of
tightening amount
Investigation of design of bearing
surrounding
Investigation of design of bearing
surrounding
Investigation of service conditions
Electrolytic
corrosion
Crater-like concave, washboard-like
flaw
Current passing
Investigation of design of bearing
surrounding
Wear
①
Extreme wear of raceway
track/rolling element
②
Wear of cage
①
Foreign matter in lubricant
②
Rusting
Investigation of lubricant and lubrication
amount
Impression
①
Concave (raceway track, etc.)
②
Ground-like
③
Impact during handling
④
Flaw caused when assembling
Dust/foreign matter rolled between rolling
element and raceway track
Careless handling (dropping, etc.)
Careless assembling
Investigation of working conditions when
handling or assembling
Careful handling
Correct assembling
Damaged
cage
①
Damage
②
Biased wear
③
Wear of pocket portion
④
Galling
①
Moment load
②
High-speed rotation
①
Lubrication failure
②
Foreign matter
Careful handling and review of service
conditions
Investigation of lubrication amount or
lubricant
Seizure
①
Discoloring/softening of raceway
track ring/rolling element
②
Damage
①
Clearance is too small
②
Insufficient lubrication
③
Improper lubricant
Overload
①
Investigation of proper clearance
②
Investigation of lubrication amount and
lubricant
③
Review of service conditions
④
Investigation of handling
Smearing
Galling of raceway track or rolling
element surface
①
Lubrication failure
②
Inclination of rolling element
(skewing)
③
Selection of lubricant
Investigation of lubricant/lubricating
conditions
Creep
Wear, slipping, or discoloring of inside /
outside diameter surface
①
Insufficient interference of engagement
②
Insufficient tightening of sleeve
①
Investigation of tightening amount
②
Investigation of machining accuracy of
shaft/bearing housing
③
Design investigation
Cracking /
chipping
①
Cracking
②
Mis-cutting
①
Progress of impact/strike flaking
②
Large interference
Large R of installation
①
Careful handling
②
Investigation of tightening amount
③
Investigation of machining accuracy of
shaft/bearing housing
Rusting
①
Rusting over entire surface
②
Partial rusting
③
Contact corrosion of engaged
surface
①
Wrong storage condition
②
Leaving to stand
③
Improper cleaning
④
Rust preventive agent
①
Improper packing
②
Sweat
①
Insufficient interference
②
Fluctuating load
①
Investigation of storage place
②
Caution in handling
③
Investigation of rust preventive agent
①
Review of machining of shaft-bearing
housing
②
Review of service conditions
