>> P.72
■FitAstheouterringisthin,thecorrectdimensionsandaccuracyofShellTypeNeedleRollerBearingsareobtainedonlyaftertheyhavebeenpress-fittedintothehousingbore.Bearingaccuracyisdirectlyaffect-edbyhousingdimensions,shapeandrigidity.Thisshouldbetakenintoaccountwhenconsideringfitandaccuracy.Theradialclearanceafterfittingthebear-ingtotheshaftandthehousingborevarieswiththeirtolerances.Table4showstherecommendedfitforShellTypeNeedleRollerBearings.Table5showsacalculationexampleofradialclear-anceafterfitting.Thiscalculationappliestobearingswithoutinnerringtobefittedintorigidsteelorcastironhousings.Whenthehousingismadeoflightalloyorathinsteelpipe,itisnecessarytocheckdimensionsbyactualmeasurement.Generally,whenmakingtheradialclearancesmaller,ittheshaftdiameterbeincreased,withoutdecreasingthehousingborediam-eter.recommendedthatisTable4RecommendedfitTypeofbearingHousingmaterialTA…Z,BA…Z,BHA…Z,TAM,BAM,BHAM,YT,YB,YBHTLA…Z,TLAM,YTL,TLA…UUSteelCastironLightalloy(Thinsteelpipe)SteelCastironLightalloy(Thinsteelpipe)ToleranceclassShaft(1)WithoutinnerringWithinnerringh6h6h6h6k5(j5)k5(j5)k5(j5)k5(j5)HousingboreJ7M7(N7)N7R7(S7)Note(1)Whenhousingsaremadeoflightalloyorathinsteelpipe,therollersetborediameterisgreatlyaffectedbythehousingthicknessandtheamountofdimensionalTherefore,beforemass-productionassembly,assemblytestsshouldbecarriedoutshape.changeandtodeterminethetoleranceoftheshaftwhichwillgivenormalclearances.toconfirmCalculationprocedureExampleofTLA2020ZDimensionofrollersetborediameterofbearingafterithasbeenpress-fittedintotheringgauge.1Dimensionofringgauge(D0):SeeTables2.1and2.2onpageB4.Max.valueofrollersetboredia.(Fwmax):No-godimensionofpluggaugeMin.valueofrollersetboredia.(Fwmin):GodimensionofpluggaugeFromTable2.1onpageB4=25.972D0Fwmax=20.028Fwmin=20.007Dimensionofhousingbore2Max.valueofhousingbore(Dmax):Seethedimensiontable.Min.valueofhousingbore(Dmin):Seethedimensiontable.FromthedimensiontableonpageB14,Dmax=25.993Dmin=25.972DFwDimensionofrollersetborediameterofbearingafterithasbeenpress-fittedintothehousingbore3Max.valueofrollersetboredia.(Fwemax)=(Dmax-D0)+FwmaxMin.valueofrollersetboredia.(Fwemin)=(Dmin-D0)+FwminFromtheequations,Fwemax=20.049Fwemin=20.007rGFTable5Calculationexampleofradialclearanceafterfittingunit: mmDimensionofshaft4Max.valueofshaftdia.(Fmax):Seethedimensiontable.Min.valueofshaftdia.(Fmin):Seethedimensiontable.Radialclearanceaftermounting5Max.valueofradialclearance(Grmax)=Fwemax-FminMin.valueofradialclearance(Grmin)=Fwemin-FmaxDFwFGr:Housingborediameter:Rollersetborediameter:Shaftdiameter:RadialclearanceB5FromthedimensiontableonpageB14,Fmax=20.000Fmin=19.987Fromtheequations,Grmax=0.062Grmin=0.007Theradialclearanceaftermountingbecomes0.007~0.062mm.
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