外文翻译--基本额定动负荷与寿命.doc

英文原文BasicDynamicLoadRatingandLifeLifeRollingbearingswillsufferdamageduetovariouscausesduringservice.Damagesuchasabnormalwear,seizure,andcracksiscausedbyimproperuse,includingincorrectmounting,lackofoil,dustintrusionandsoon,andcanbeavoidedbyremedyingthesecauses.However,bearingswilleventuallybedamagedduetofatigue-flakingevenifusedproperly.Whenabearingrotatesunderload,theracewaysandtherollingelementsaresubjectedtorepeatedstress-esconcentratedonthepartclosetothesurface.Fatigue,therefore,occursinthesurfacelayer,producingdamageintheformofscaling.Thisiscalledflaking(spalling).Whenthisoccurs,thebearingcannolongerbeused.BearingLifeBearinglifeisdefinedasthetotalnumberofrevolutions(ortotalservicehoursataconstantrotationalspeed)beforeasignofthefirstflakingappearsontherollingsurfaceofracewayorrollingelements.However,evenwhenbearingsofthesamesize,structure,materialandheattreatmentaresubjectedtothesameconditions,thebearingliveswillshowvariation.Thisresultsfromthestatisticalnatureofthefatiguephenomenon.Inselectingabearing,itisincorrecttotakeanaver-agelifeforallbearingsasthedesignstandard.Itismorepracticaltoconsiderabearinglifethatisreliableforthegreaterproportionofbearingsused.Therefore,thebasicratinglifedefinedinthefollowingisused.BasicratinglifeThebasicratinglifeisdefinedasthetotalnumberofrevolutionsthat90%ofagroupofidenticalbearingscanbeoperatedindividuallyunderthesameconditionsfreefromanymaterialdamagecausedbyrollingfatigue.Forrotationataconstantrotationalspeed,thebasicratinglifecanberepresentedbythetotalservicehours.BasicdynamicloadratingThebasicdynamicloadratingisdefinedastheconstantradialload(inthecaseofradialbearings)ortheconstantaxialloadactingalongthebearingcentralaxis(inthecaseofthrustbearings)thatallowsabasicratinglifeof1,000,000revolutionsIKOCamFollowersarebearingswithastudincorporatingneedlerollersinathickwalledouterring.Thesebearingsaredesignedforouterringrotation,andhavesuperiorrotationalperformancewithasmallcoefficientoffrictionandhighloadcapacity.Asstudsalreadyhavethreadsorsteps,theyareeasytomount.CamFollowersarefollowerbearingsforcammechanismsandlinearmotionsandhavehighrigidityandhighaccuracy.Theyare,therefore,usedwidelyformachinetools,industrialrobots,electronicdevices,andOAequipment.StainlesssteelmadeCamFollowersaresuperiorincorrosionresistanceandsuitableforapplicationsinenvironmentswhereoilcannotbeusedorwatersplashed,andincleanrooms.Types1、StandardTypeCamFollowersThesearethebasictypebearingsinIKOCamFollowerseries.Modelswithstuddiametersrangingfrom3to30mmareprepared,andaresuitableforawiderangeofapplications.2、SolidEccentricStudTypeCamFollowersThestudofthesebearingsiseccentrictothecenteraxisoftheouterring.Thus,thepositionoftheouterringintheradialdirectioninrelationtothematingtracksurfacecaneasilybeadjustedbyturningthestud,andtheloaddistributiononanumberofcamfollowerouterringsusedonthesametracksurfacecanbemadeuniform.Theseareeccentriccamfollowerswithaone-piecestudthatcanbemountedinthesamemountingholesasthoseforStandardTypeCamFollowers.Eccentricityis0.25mm0.6mm.3、EccentricTypeCamFollowersInthesebearings,aneccentriccollarisassembledwiththeCamFollowerstud,enablingtheouterringtobepositionedeasilyintheradialdirectionagainstthematingtracksurface.Eccentricityis0.41.5mm.4、ThrustDiskTypeCamFollowersThesebearingshavespecialresinthrustdiskwash-erssuperiorinwearandheatresistancebetweentheslidingsurfacesofouterringshoulders,studheadandsideplate.Thesediskwashersreducefrictionandwearduetoaxialloadscausedbymisalignment,etc.5、CentralizedLubricationTypeCamFollowersThesebearingshaveoneortwopipe-threadedholesinthestud.Thus,thisseriesissuitablewhencentralizedlubricationisrequired.6、EasyMountingTypeCamFollowersThesebearingshaveasteppedtaperedportiononthestud.WhenmountingtheCamFollower,itiseasytofixitslocationbytighteningasetscrewtothesteppedportion.Thus,thistypeissuitablewhenalargenumberofCamFollowersareusedinamachinesuchasapalletchanger.7、C-lubeCamFollowerThesebearingsarelubricatedwithanewlydevelopedthermosettingsolid-typelubricantwhichfillstheinnerspaceofthebearing.Thislubricantprovideslong-termmaintenancefree.8、HeavyDutyTypeCamFollowersThesebearingsarefullcomplementtypebearingsincorporatingdoublerowsoffullcomplementcylindricalrollersintheouterring,andcanwithstandlargeradialloadsandsomeaxialloads.9、MiniatureTypeCamFollowersThesearecompactlydesignedbearings,incorporatingverythinneedlerollersinanouterringwithasmalloutsidediameter.Theyareusedinelectronicdevices,OAequipment,smallindexdevices,etc.10、InchseriesCamFollowersTwotypes,CRandCRH,areavailableintheInchseriesCamFollowers.BlackoxidefilmtreatmentismadeonCRHmodels.MaximumAllowableStaticLoadTheapplicableloadonCamFollowersis,insomecases,limitedbythebendingstrengthandshearstrengthofthestudandthestrengthoftheouterringinsteadoftheloadratingoftheneedlerollerbearing.Therefore,themaximumallowablestaticloadthatislmitedbythesestrengthsisspecified.TrackCapacityTrackcapacityisdefinedasaloadwhichcanbecontinuouslyappliedonaCamFollowerplacedonasteeltracksurfacewithoutcausinganydeformationorindentationonthetracksurfacewhentheouterringoftheCamFollowermakescontactwiththematingtracksurface(plane).Iflubricationbetweentheouterringandthematingtracksurfaceisinsufficient,seizureand/orwearmayoccurdependingontheapplication.Therefore,attentionmustbepaidtolubricationandsurfacerough-nessofthematingtrackespeciallyforhigh-speedrotationssuchascammechanisms.OperatingTemperatureRangeTheoperatingtemperaturerangeforCamFollowersis-20.C+120C.However,themaxi-mumallowabletemperatureforthefollowingtypesisdifferent.ThemaximumallowabletemperaturefortheMetricCFserieswithastuddiameterd1of4mmorlessandCFS2is+110C,and+100Cwhentheyarecontinuouslyoperated.Themaximumallowabletemperatureforthesealedtypewithastuddiameterd1of5mmorlessis+80C.Mounting1、MakethecenteraxisofthemountingholeperpendiculartothemovingdirectionoftheCamFollowerandmatchthesideshoulderaccuratelywiththeseatingsurfaceindicatedbydimensionfinthetableofdimensions.Then,fixtheCamFollowerwiththenut.DonothittheflangeheadoftheCamFollowerdirectlywithahammer,etc.Thismayleadtoabearingfailuresuchasirregularrotationorcracking.2、TheIKOmarkontheflangeheadofthestudindicatesthepositionoftheoilholeontheraceway.Avoidlocatingtheoilholewithintheloadingzone.Thismayleadtoashortbearinglife.Theholelocatedinthemiddlepartofthestudperpendiculartothestudcenteraxisisusedforgreasingorlocking3、Whentighteningthenut,thetighteningtorqueshouldnotexceedthevaluesshowninthetableofdimensions.Ifthetighteningtorqueistoolarge,itispossiblethatthethreadedportionofthestudwillbebroken.Whenthereisapossibilityofloosening,aspecialnutsuchasalocknut,springwasher,orself-lockingnutshouldbeused.4、InthecaseofSolidEccentricStudTypeCamFollowersandEccentricTypeCamFollowers,theouterringpositioncanbeadjustedappropriatelybyturningthestudwithascrewdriverorhexagonbarwrenchusingthescrewdriverslotorhexagonholeofthestudhead.Thestudisfixedwithanutandaspringwasher,etc.Thetighteningtorqueshouldnotexceedthevaluesofmaximumtighteningtorqueshowninthetableofdimensions.Whenshockloadsareappliedandtheadjustedeccentricityhastobeensured,itisrecommendedtomakeholesinthehousing,studandeccentriccollar,andfixthestudwithadowelpinasshowninfollowing.However,whenthestuddiameterislessthan8mm(Eccentriccollardiameter11mm),itisdifficulttomakeaholeinthestudbecausethestudisthrough-hardened.5、IncaseofEccentricTypeCamFollowers(CFE),thelengthofthemountingholeshouldbemorethan0.5mmlongerthanthedimensionofEccentriccollarwidth.6、FormountingEasyMountingTypeCamFollowers,itisrecommendedtofixthefixingscrewfromtheuppersidetothesteppedportionofthestud.InspectionofbearingCleaningofbearingWheninspectingabearingafterremoval,theappear-anceofthebearingshouldberecordedfirst.Then,aftertheresidualamountoflubricantischeckedandasampleoflubricantiscollected,thebearingshouldbecleaned.Forcleaning,lightoilorkeroseneiscommonlyused.Cleaningisdividedintoroughcleaningandfinalcleaning,andwiregauzeissetasaraisedbottominacontainertopreventthebearingfromtouchingthebottomofthecontainer.Lubricatinggreaseandadheringsubstancessuchasforeignparticlesareremovedwithabrush,etc.,usingoilforroughcleaning.Careshouldbetakenduringthisprocess,becauseifthebearingisturnedwithforeignparticlesattached,theracewaysurfacesmaybescratched.Finalcleaningiscarriedoutbyturningthebearingincleaningoil.Itisdesirablethatthecleaningoiliskeptcleanbyfiltering.Immediatelyaftercleaning,thebearingmustbeprotectedagainstcorrosion.InspectionandevaluationofbearingThejudgmentastowhethertheremovedbearingisreusabledependsontheinspectionaftercleaning.Conditionsoftheracewaysurfaces,rollingelementsandfittingsurfaces,wearconditionofthecage,increaseofbearingclearance,dimensions,rotationalaccuracy,etc.shouldbecheckedfordamageandabnormalities.Theevaluationisperformedbasedontheexperiencetakingintoconsiderationthedegreeofdamage,machineperformance,importanceofthemachine,operatingconditions,perioduntilthenextinspection,andothersuchfactors.MaintenanceandinspectionMaintenanceandinspectionarecarriedouttomain-taingoodperformanceofbearingsinstalledinthemachine.Maintenanceisperformedbycheckingthemachineoperatingconditions,checkingandreplenishingorreplacingthelubricant,checkingthebearingandrelatedpartsbyperiodicdisassemblyandothersuchprocedures.Itemsforinspectionofarunningbearinginamachineincludethebearingtemperature,noise,vibrationandconditionoflubricant.Damage,causesandcorrectiveactionRollingbearingscangenerallybeusedfullyuptotheirrollingfatiguelifeiftheyareproperlyselected,mounted,operatedandmaintained.However,theymayactuallybedamagedearlierthantheirexpectedlifetimescreatingproblemsoraccidents.Commoncausesofdamageincludeimpropermountingorhandling,insufficientlubricationandpenetrationofforeignparticles.Itmaybedifficulttodeterminetheexactcauseofaproblembycheckingonlythedamagedbearing.Theconditionsofthemachinebeforeandaftertheoccurrenceofthedamage,thelocationandtheoperatingandambientconditionsofthebearing,thestructurearoundthebearing,etc.shouldalsobeexamined.Itthenbecomespossibletoassessthecauseofthedamagebylinkingtheconditionsofthedamagedbearingtotheprobablecausesarisingfromthemachineoperation,andtopreventtherecurrenceofsimilarproblems.