>> P.274
G3ModelcodeDimensionsNAXI17Typeofbearing30Examplesofidenti(cid:16)cationnumberExample1Example2ModelcodeDimensionsNATA59Typeofbearing05ZP6SupplementalcodeClassificationsymbolBearingborediameter(17mm)DimensionseriesBorediameternumberWithdustcoverAccuracyclass(Class6)Assembledbearingwidth(30mm)TheidentificationnumberofCombinedTypeNeedleRollerBearingsconsistsofamodelcode,dimen-sions,anysupplementalcodesandaclassificationsymbol.Someexamplesareshownbelow.■IdentificationNumberNeedleRollerBearingswithThrustRollerBearingInthisseries,needlerollerbearingsarecombinedwiththrustrollerbearingstoreceivethrustloads.Theiraxialloadratingsaregreaterthanthoseofbear-ingsthatarecombinedwiththrustballbearings.Also,elasticdeformationoftherollingcontactsurfacesunderloadisminimal.Furthermore,thethrustbear-ingsectionisfinishedtohighaccuracy,andthereforehighrotationalaccuracyisobtainedinthecaseofbothverticalandhorizontalshafts.Liketheneedlerollerbearingswiththrustballbearing,thisseriesalsoincludesbearingswithadustcoverandbearingswithaninnerring.NeedleRollerBearingswithAngularCon-tactBallBearingInthisseries,cagedneedlerollerbearingsarecom-binedwithangularcontactballbearingstoreceivethrustloads.Thesebearingsconformtotheinterna-tionaldimensionseries#59,whichisbasedontheISOStandard.Theycanwithstandheavyradialloadsandunidirectionalaxialloadssimultaneously.Whentheaxialloadexceeds25%oftheradialload,theradialloadwillbeinducedintheangularcontactballbearing,andbearinglifewillbeaffected.Therelationshipbetweenthetwoloadsmustthereforebetakenintocarefulconsideration.NeedleRollerBearingswithThree-pointContactBallBearingThesebearingscanwithstandheavyradialloadsandbi-directionalaxialloadsatthesametimeduringhigh-speedrotation.Sincethenon-interchangeableinnerringsaresepa-ratedatthecenteroftheballracewaysurface,theymustbefirmlytightenedagainsttheshaftintheaxialdirection.Theaxialclearanceofthisbearingis0.1〜0.3mm,andlikeNATA59,theaxialloadshouldnotexceed25%oftheradialload.■AccuracyDimensionalaccuracyandrotationalaccuracyofCombinedTypeNeedleRollerBearingsarebasedonTable2belowandTables12and13onpageA31.ThetolerancesforthesmallestsinglerollersetborediameterofbearingswithoutinnerringarebasedonTable14onpageA33.ThicknessvariationsofthrustringsofNAX(I)andNBX(I)arebasedonTable2.4onpageF5.BorediameterofthesmallwidthinnerringofNATB59ismadeforatransitionfitwithk5toleranceshaft.
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