>> P.78
1-5HandlingBearingsPrecautionsforUseandAssemblyOilwipingItmaybenecessarytowipeofftherust-proofingoilappliedtothebearingouterandinnerdiameterbeforeinstalling;solvents,etc.,willenterthebearingandcauseabnormalnoiseandrotationdefects.•Useacleandust-proofcloth,etc.Keeptheproductcleanwithconsiderationfortheusagefrequency.•MinimizetheuseofsolventsWhileitisnormaltoapplysolventssuchasalcoholtotheclothbeforewipingclean,keeptheuseofsolventstoaminimum.Solventsusedinexcesswillcarrydustintothebearing,generatingnoise.FitsUnsuitablefitwillleadtocreep(slidingwear),rotationdefects(hightorque,vibration,heatgeneration),brinelling,etc.•Shaftandhousingroundness•ShaftandhousingchamferingBecarefulwiththeshaftandhousingroundness.Theshaftandhousingshapewillbetransferredtotheinnerandouterringrollingcontactgroove,worseningtheroundnessandgeneratingvibration,abnormalnoise,andrunout.Becarefulwiththesizeandshapeofthechamferedshaftandhousingpartsthathitthebearingends.Ifthechamferinginterferes,assemblyinthecorrectpositionwillnotbepossible,leadingtomisalignment(assemblyprecisiondefects).•Shaftandhousingdimensions•ShaftandhousingburrsandscratchesCheckthattheshaftandhousingdimensionsarecorrect.Excesspress-fittingonthefitsideduetodimensionaldefectswillleadtorotationdefects(torque,vibration,heatgeneration),brinelling,etc.•Shaftandhousingshape(designprecautions)Becarefulwiththeshaftandhousingshape.Discontinuityintheshaftouterperimeterorscrewsonthehousingendmayworsentheinnerandouterringroundness.Checkthattherearenoburrsorscratchesontheshaftandhousing.Ifburrsinterferewiththebearingcontactsurface,misalignment(assemblyprecisiondefects)maybegenerated;scratchesonthefitsurfacemayleadtoworsenedinnerandouterringrollingcontactgrooveroundness.MinebeaMitsumiprovidesvariousunitproducts(PMAproducts)combiningshaftsandhousingswithbearings.ForPMAproducts▶78