Get to know bearing better
- Bearing Failures and Counter Detecting and Correcting Irr Inspection of Bearings
Operation Inspection
After the mounting has been completed, a running test should be conducted to determine if the bearing has been mounted correctly. Small machines may be manually operated to assure that they rotate smoothly. Items to be checked include sticking due to foreign matter, visible flaws, uneven torque caused by improper mounting or an improper mounting surface and excessive torque caused by an inadequate clearance, mounting error, or seal friction. If there are no abnormalities, powered operation may be started.
Large machines, which cannot be turned by hand, can be started after examination with no load, and the power immediately cutoff and the machine allowed to coast to a stop. Confirm that there is no abnormality such as vibration, noise, contact of rotating parts, etc. Powered operation should be started slowly without load and the operation should be observed carefully until it is determined that no abnormalities exist, then gradually increase the speed, load, etc. to their normal levels. Items to be checked during the test operation include the existence of abnormal noise, excessive rise of bearing temperature, leakage and contamination of lubricants, etc. If any abnormality is found during the test operation, it must be stopped immediately and the machine should be inspected. If necessary, the bearing should be dismounted for examination.Irregularities
Possible Causes
Countermeasures
Noise
Loud
Metallic
Sound
Abnormal Load
Incorrect mounting
Insufficient
or improper
LubricantContact of rotating parts
Improve the fit, internal clearance,
preload, position of housing shoulder, etc.
the machining accuracy and
Improvealignment of shaft and housing, accuracy
of mounting method.
Replenish the lubricant or select another
lubricant.
Modify the labyrinth seal, etc.Loud
Regular
Sound
Flaws,corrosion,or scratches
on racewaysBrinelling
Flaking on raceway
Replace or clean the bearing, improve the
seals, and use clean lubricant.
the bearing and use care when
Replace
handling bearings.Replace the bearing.
Irregular
Sound
Excessive clearance
Penetration of foreign particles
Flaws or flaking on ballsImprove the fit, clearance and preload.
Replace or clean the bearing, improve
the seals, and use clean lubricant.Replace the bearing.
Abnormal
Temperature
Rise
Excessive amount of lubricant
Insufficient
or improper lubricant
Abnormal load
Incorrect mounting
on fitted surface, excessive
Creepseal friction
Reduce amount of lubricant, select stiffer grease.
Replenish lubricant or select a better one.
Improve the fit, internal clearance, preload,
position of housing shoulder.
the machining accuracy and
Improve
alignment of shaft and housing,
accuracy of mounting, or mounting method.
Correct the seals, replace the bearing,
correct the fitting or mounting.Vibration
(Axial
runout)
Brinelling
Flaking
Incorrect mounting
of foreign particles
PenetrationReplace the bearing and use care when
handling bearings.
Replace the bearing.Correct the squareness between the shaft
and housing shoulder or side of spacer.
Replace or clean the bearing, improve the seals.Leakage or
Discoloration
of Lubricant
Too much lubricant, Penetration
by foreign matter or abrasion chipsReduce the amount of lubricant, select a
stiffer grease. Replace the bearing or
lubricant. Clean the housing and
adjacent parts.