>> P.82
1-6MalfunctionSymptoms,Causes,andCountermeasuresInthecaseofabnormalitiesinthedevicewiththebearingmounted,ordamagetothebearing,thesymptomscanbeaguidetothecause.Belowaresometypicalabnormalitiesandtheircountermeasures.Abnormalitysymptoms/statusSymptoms/statusBearingdamagestatus/suspectedcauses,etc.DamageexamplesCountermeasureBrinellingonracewaygrooveRoughness/wearContinuousnoiseScratches(indentation)duetoracewaygroovecontaminationAbnormalnoiseFrettingcorrosionElectriccorrosion31246Reviewofbearinghandling,assemblywork,devicetransportwork(possibleoverloadorimpactload)Reviewoflubricant,bearingsize,preload,sealReviewofbearingsealing,workenvironmentReviewofvibratinprevention,packaging/conveyanceInsulationmeasures:UseceramicballsResonanceofcomponentsReviewofcomponentdimensions(thickness)/materialsIntermittentnoiseScratchesonballsReviewofworkenvironmentandprocess(possiblecontaminationoroverload)ContaminationbitedamageReviewofbearingsealing,workenvironmentInsufficientpreloadEffectsoflubricant(grease)(amount,type)Reviewofpreloadamountbasedonload/rotationconditions,etc.Reviewofgrease,improvement(increaseddrivepower,etc.)ofdriveparts(motorparts,etc.)ContaminationoradhesiveingressReviewofworkenvironmentandmethodsNorotationorsluggishrotationLargeinterferenceLubricationrunsdryRotationdefectsFlakingPartcontactHeatgenerationUnsuitabletypeandamountofgreaseReviewoffitReviewoflubricant,increasedgreaseamountReviewofgreasetype/amount7Confirmationofload/rotationconditionsSelectionoflargerbearingReviewofworkanddesignReviewofgreaseOverloadReviewofloadresistanceandfitShortlifeUnsuitableenvironment/operatingconditions,etc.MisalignmentRacewaysurfacedeformationUnsuitablepreloadFallenpreloadLargeinternalclearanceCreepUnsuitabletypeandamountofgreaseLargevibration/runoutGreaseleakReviewofenvironment/operatingconditionsReviewofpartdimensions/tolerances,clanliness,workReviwofbearingorhousigmachinedaccuracy(roundness),reviewofadhesiveandadhesiveapplicationworkReviewofpreloadamountbasedonload/rotationconditions,etc.Reducedbearinginternalclearance5ReviewoffitReviewofgreaseUnsuitableselectionofshield/sealReviewofshield/sealEnvironmentalstresscracking(ESC)Reviewoflubricant,stressmiigation,reselectionofresinResinmaterialdamage(split)ExcessinterferenceWeldlinesNote:Damageexamplesarenumberedinorderoffrequency82ReviewoffitReviewofmoldingconditions,gateposition