外文翻译(汽车差速器)(适用于毕业论文外文翻译+中英文对照)_第1页
外文翻译(汽车差速器)(适用于毕业论文外文翻译+中英文对照)_第2页
外文翻译(汽车差速器)(适用于毕业论文外文翻译+中英文对照)_第3页
外文翻译(汽车差速器)(适用于毕业论文外文翻译+中英文对照)_第4页
外文翻译(汽车差速器)(适用于毕业论文外文翻译+中英文对照)_第5页
全文预览已结束

下载本文档

版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领

文档简介

WFAILUREANALYSISOFANAUTOMOBILEDIFFERENTIALPINIONSHAFTABSTRACTDIFFERENTIALISUSEDTODECREASETHESPEEDANDTOPROVIDEMOMENTINCREASEFORTRANSMITTINGTHEMOVEMENTCOMINGFROMTHEENGINETOTHEWHEELSBYTURNINGITACCORDINGTOTHESUITABLEANGLEINVEHICLESANDTOPROVIDETHATINNERANDOUTERWHEELSTURNDIFFERENTLYPINIONGEARANDSHAFTATTHEENTRANCEAREMANUFACTUREDASASINGLEPARTWHEREASTHEYAREINDIFFERENTFORMSACCORDINGTOAUTOMOBILETYPESMIRRORGEARWHICHWILLWORKWITHTHISGEARSHOULDBECOMEFAMILIARBEFORETHEASSEMBLYINCASEOFANYBREAKDOWNTHEYSHOULDBECHANGEDASAPAIRGENERALLYINTHESESYSTEMSTHEREAREWEARDAMAGESINGEARSTHEGEARINSPECTEDINTHISSTUDYHASDAMAGEASAFORMOFSHAFTFRACTUREINTHISSTUDYFAILUREANALYSISOFTHEDIFFERENTIALPINIONSHAFTISCARRIEDOUTMECHANICALCHARACTERISTICSOFTHEMATERIALAREOBTAINEDFIRSTTHENTHEMICROSTRUCTUREANDCHEMICALCOMPOSITIONSAREDETERMINEDSOMEFRACTOGRAPHICSTUDIESARECARRIEDOUTTOASSESTHEFATIGUEANDFRACTURECONDITIONSKEYWORDSDIFFERENTIALFRACTUREPOWERTRANSFERPINIONSHAFT1INTRODUCTIONTHEFINALDRIVEGEARSMAYBEDIRECTLYORINDIRECTLYDRIVENFROMTHEOUTPUTGEARINGOFTHEGEARBOXDIRECTLYDRIVENFINALDRIVESAREUSEDWHENTHEENGINEANDTRANSMISSIONUNITSARECOMBINEDTOGETHERTOFORMANINTEGRALCONSTRUCTIONINDIRECTLYDRIVENFINALDRIVESAREUSEDATTHEREAROFTHEVEHICLEBEINGEITHERSPRUNGANDATTACHEDTOTHEBODYSTRUCTUREORUNSPRUNGANDINCORPORATEDINTHEREARAXLECASINGTHEFINALDRIVEGEARSAREUSEDINTHETRANSMISSIONSYSTEMFORTHEFOLLOWINGREASONS1ATOREDIRECTTHEDRIVEFROMTHEGEARBOXORPROPELLERSHAFTTHROUGH90ANDBTOPROVIDEAPERMANENTGEARREDUCTIONBETWEENTHEENGINEANDTHEDRIVINGROADWHEELSINVEHICLESDIFFERENTIALISTHEMAINPARTWHICHTRANSMITSTHEMOVEMENTCOMINGFROMTHEENGINETOTHEWHEELSONASMOOTHROADTHEMOVEMENTCOMESTOBOTHWHEELSEVENLYTHEINNERWHEELSHOULDTURNLESSANDTHEOUTERWHEELSHOULDTURNMORETODOTHETURNINGWITHOUTLATERALSLIPPINGANDBEINGFLUNGDIFFERENTIALWHICHISGENERALLYPLACEDINTHEMIDDLEPARTOFTHEREARBRIDGECONSISTSOFPINIONGEARMIRRORGEARDIFFERENTIALBOXTWOAXLEGEARANDTWOPINIONSPIDERGEARSASCHEMATICILLUSTRATIONOFADIFFERENTIALISGIVENINFIG1THETECHNICALDRAWINGOFTHEFRACTUREDPINIONSHAFTISALSOGIVENINFIG2FIG3SHOWSTHEPHOTOGRAPHOFTHEFRACTUREDPINIONSHAFTANDTHEFRACTURESECTIONISINDICATEDINDIFFERENTIALSMIRRORANDPINIONGEARAREMADETOGETUSEDTOEACHOTHERDURINGMANUFACTURINGANDTHESAMESERIALNUMBERISGIVENBOTHOFTHEMARECHANGEDONCONDITIONTHATTHEREAREANYPROBLEMSINTHESESYSTEMSTHECOMMONDAMAGEISTHEWEAROFGEARS24INTHISSTUDYTHEPINIONSHAFTOFTHEDIFFERENTIALOFAMINIBUSHASBEENINSPECTEDTHEMINIBUSISADIESELVEHICLEDRIVENATTHEREARAXLEANDHASAPASSENGERCAPACITYOF15PEOPLEMAXIMUMENGINEPOWERIS90/4000HP/RPMANDMAXIMUMTORQUEIS205/1600NM/RPMITSTRANSMISSIONBOXHASMANUALSYSTEM5FORWARD1BACKTHEDAMAGEWASCAUSEDBYSTOPPINGANDSTARTINGTHEMINIBUSATATRAFFICLIGHTSINTHISDIFFERENTIALENTRANCESHAFTWHICHCARRIESTHEPINIONGEARWASWBROKENVARIOUSSTUDIESHAVEBEENMADETODETERMINETHETYPEANDPOSSIBLEREASONSOFTHEDAMAGETHESEARESTUDIESCARRIEDOUTTODETERMINETHEMATERIALOFTHESHAFTSTUDIESCARRIEDOUTTODETERMINETHEMICROSTRUCTURESTUDIESRELATEDTOTHEFRACTURESURFACETHEREISACLOSERPHOTOGRAPHOFTHEFRACTUREDSURFACESANDFRACTUREAREAINFIG4THEFRACTUREWASCAUSEDBYTAKINGOUTCIRCULARMARKGEARSEENINTHEMIDDLEOFSURFACESFIG1SCHEMATICOFTHEANALYSEDDIFFERENTIALFIG2TECHNICALDRAWINGOFTHEANALYSEDPINIONSHAFTWFIG3THEPICTUREOFTHEUNDAMAGEDDIFFERENTIALPINIONANALYSEDINTHESTUDYFIG4PHOTOGRAPHSOFFAILEDSHAFT2EXPERIMENTALPROCEDURESPECIMENSEXTRACTEDFROMTHESHAFTWERESUBJECTEDTOVARIOUSTESTSINCLUDINGHARDNESSTESTSANDMETALLOGRAPHICANDSCANNINGELECTRONMICROSCOPYASWELLASTHEDETERMINATIONOFCHEMICALCOMPOSITIONALLTESTSWERECARRIEDOUTATROOMTEMPERATURE21CHEMICALANDMETALLURGICALANALYSISCHEMICALANALYSISOFTHEFRACTUREDDIFFERENTIALMATERIALWASCARRIEDOUTUSINGASPECTROMETERTHECHEMICALCOMPOSITIONOFTHEMATERIALISGIVENINTABLE1CHEMICALCOMPOSITIONSHOWSTHATTHEMATERIALISALOWALLOYCARBURISINGSTEELOFTHEAISI8620TYPEHARDENABILITYOFTHISSTEELISVERYLOWBECAUSEOFLOWCARBONPROPORTIONTHEREFORESURFACEAREABECOMESHARDANDHIGHLYENDURINGANDINNERAREASBECOMESTOUGHBYINCREASINGCARBONPROPORTIONONTHESURFACEAREAWITHCEMENTATIONOPERATIONTHISISTHEKINDOFSTEELWHICHISGENERALLYUSEDINMECHANICALPARTSSUBJECTEDDOTORSIONANDBENDINGHIGHRESISTANCEISOBTAINEDONTHESURFACEANDHIGHFATIGUEENDURANCEVALUECANBEOBTAINEDWITHCOMPRESSIVERESIDUALSTRESSBYMAKINGTHESURFACEHARDER57INWHICHALLOYELEMENTSDISTRIBUTETHEMSELVESINCARBONSTEELSDEPENDSPRIMARILYONTHECOMPOUNDANDCARBIDEFORMINGTENDENCIESOFEACHELEMENTNICKELDISSOLVESINTHEAFERRITEOFTHESTEELSINCEITHASLESSTENDENCYTOFORMCARBIDESTHANIRONSILICONCOMBINESTOALIMITEDEXTENTWITHTHEOXYGENPRESENTINTHESTEELTOFORMNONMETALLICWINCLUSIONSBUTOTHERWISEDISSOLVESINTHEFERRITEMOSTOFTHEMANGANESEADDEDTOCARBONSTEELSDISSOLVESINTHEFERRITECHROMIUMWHICHHASASOMEWHATSTRONGERCARBIDEFORMINGTENDENCYTHANIRONPARTITIONSBETWEENTHEFERRITEANDCARBIDEPHASESTHEDISTRIBUTIONOFCHROMIUMDEPENDSONTHEAMOUNTOFCARBONPRESENTANDIFOTHERSTRONGERCARBIDEFORMINGELEMENTSSUCHASTITANIUMANDCOLUMBIUMAREABSENTTUNGSTENANDMOLYBDENUMCOMBINEWITHCARBONTOFORMCARBIDESIFTHEREISSUFFICIENTCARBONPRESENTANDIFOTHERSTRONGERCARBIDEFORMINGELEMENTSSUCHASTITANIUMANDCOLUMBIUMAREABSENTMANGANESEANDNICKELLOWERTHEEUTECTOIDTEMPERATURE8PRELIMINARYMICROSTRUCTURALEXAMINATIONOFTHEFAILEDDIFFERENTIALMATERIALISSHOWNINFIG5ITCANBESEENTHATTHEMATERIALHASAMIXEDSTRUCTUREINWHICHSOMEFERRITEEXISTPROBABLYASARESULTOFSLOWCOOLINGANDHIGHSICONTENTHIGHSICONTENTINTHISTYPEOFSTEELIMPROVESTHEHEATTREATMENTSUSCEPTIBILITYASWELLASANIMPROVEMENTOFYIELDSTRENGTHANDMAXIMUMSTRESSWITHOUTANYREDUCTIONOFDUCTILITY9IFTHEMICROSTRUCTURECANNOTBEINVERTEDTOMARTENSITEBYQUENCHINGAREDUCTIONOFFATIGUELIMITISOBSERVEDTABLE1CHEMICALANALYSISOFTHEPINIONGEARMATERIALWTFECSIMNPSCRMONI969202350252078600440016048101510517ANDFRACTURESURFACESFIG5MICROSTRUCTUREOFTHEMATERIAL200THEREAREAREASWITHCARBONPHASEINFIG5ATHEREISTHETRANSITIONBOUNDARYOFCARBURISATIONINFIG5BANDCSHOWSTHEMATRIXREGIONWITHOUTCARBURISATIONASFARASITISSEENINTHESEPHOTOGRAPHSTHEPIECEWASFIRSTCARBURISEDTHENTHEQUENCHINGOPERATIONWASDONEANDTHANTEMPEREDTHISSITUATIONCANBEUNDERSTOODFROMBLINDMARTENSITEPLATES22HARDNESSTESTSTHEHARDNESSMEASUREMENTSARECARRIEDOUTBYAMETTESTHTTYPECOMPUTERINTEGRATEDHARDNESSTESTERTHELOADIS1471NTHEMEDIUMHARDNESSVALUEOFTHEINTERIORREGIONSISOBTAINEDAS43HRCMICROHARDNESSMEASUREMENTSHAVEBEENMADETODETERMINETHECHANCEOFHARDNESSVALUESALONGTHECROSSSECTIONBECAUSEOFTHEHARDENINGOFSURFACEAREADUETOCARBURISATIONTHERESULTSOFVICKERSHARDNESSMEASUREMENTUNDERALOADOF4903NAREILLUSTRATEDINTABLE223INSPECTIONOFTHEFRACTUREWTHEDIRECTOBSERVATIONSOFTHEPIECEWITHFRACTUREDSURFACESANDSEMANALYSESAREGIVENINTHISCHAPTERTHECRACKSTARTEDBECAUSEOFAPOSSIBLEPROBLEMINTHEBOTTOMOFNOTCHCAUSEDTHESHAFTTOBEBROKENCOMPLETELYTHECRACKSTARTEDONTHEOUTERPARTAFTERSOMETIMEITCONTINUEDBEYONDTHECENTREANDTHEREWASONLYALITTLEPARTLEFTANDTHISPARTWASBROKENSTATICALLYDURINGSUDDENSTARTINGOFTHEVEHICLEATTHETRAFFICLIGHTSASACHARACTERISTICOFTHEFATIGUEFRACTURETHEREARETWOREGIONSINTHEFRACTUREDSURFACETHESEAREASMOOTHSURFACECREATEDBYCRACKPROPAGATIONANDAROUGHSURFACECREATEDBYSUDDENFRACTURETHESETWOREGIONSCANBESEENCLEARLYFORTHEENTIREPROBLEMASINFIG4THEFATIGUECRACKPROPAGATIONREGIONCOVERSMORETHAN80OFTHECROSSSECTIONTABLE2MICROHARDNESSVALUESDISTANCEFROMSURFACELM50100200400CENTERVALUESHV4903N588410293286263FIGFIG6SEMIMAGEOFTHEFRACTURESURFACESHOWINGTHEDUCTILESHEARWFIG7SEMIMAGEOFTHEFRACTURESURFACESHOWINGTHEBEACHMARKSOFTHEFATIGUECRACKPROPAGATIONSHAFTWORKSUNDERTHEEFFECTOFBENDINGTORSIONANDAXIALFORCESWHICHAFFECTREPEATEDLYDEPENDINGONTHEUSAGEPLACETHEREISASHARPFILLETATLEVELONTHEFRACTUREDSECTIONFORTHISREASONSTRESSCONCENTRATIONFACTORSOFTHEAREAHAVEBEENDETERMINEDKT24VALUEFORBENDINGANDTENSIONANDKT19VALUEFORTORSIONHAVEBEENACQUIREDACCORDINGTOCALCULATIONSTHESEAREQUITEHIGHVALUESFORAREASEXPOSEDTOCOMBINEDLOADINGTHESEOBSERVATIONSANDANALYSISSHOWTHATTHEPIECEWASBROKENUNDERTHEINFLUENCEOFTORSIONWITHLOWNOMINALSTRESSESANDMEDIUMSTRESSCONCENTRATION10THESCANNINGELECTRONMICROSCOPYSHOWSTHATTHEFRACTUREHASTAKENPLACEINADUCTILEMANNERFIG6THEREARESOMESHEARLIPSINTHECRACKPROPAGATIONREGIONWHICHISAGLUEOFTHEPLASTICSHEARDEFORMATIONSFIG7SHOWSTHEBEACHMARKSOFTHEFATIGUECRACKPROPAGATIONTHEDISTANCEBETWEENANYTWOLINESISNEARLY133NM3CONCLUSIONSAFAILEDDIFFERENTIALPINIONSHAFTISANALYSEDINTHISSTUDYTHEPINIONSHAFTISPRODUCEDFROMAISI8620LOWCARBONCARBURISINGSTEELWHICHHADACARBURISINGQUENCHINGANDTEMPERINGHEATTREATMENTPROCESSMECHANICALPROPERTIESMICROSTRUCTURALPROPERTIESCHEMICALCOMPOSITIONSANDFRACTOGRAPHICANALYSESARECARRIEDOUTTODETERMINETHEPOSSIBLEFRACTUREREASONSOFTHECOMPONENTASACONCLUSIONTHEFOLLOWINGSTATEMENTSCANBEDRAWNTHEFRACTUREHASTAKENPLACEATAREGIONHAVINGAHIGHSTRESSCONCENTRATIONBYAFATIGUEPROCEDUREUNDERACOMBINEDBENDINGTORSIONANDAXIALSTRESSESHAVINGHIGHLYREVERSIBLENATURETHECRACKOFTHEFRACTUREISINITIATEDPROBABLYATAMATERIALDEFECTREGIONATTHECRITICALLOCATIONTHEFRACTUREISTAKENPLACEINADUCTILEMANNERPOSSIBLELATERFAILURESMAYEASILYBEPREVENTEDBYREDUCINGTHESTRESSCONCENTRATIONATTHECRITICALLOCATIONW汽车差速器小齿轮轴的失效分析摘要差速器的作用是根据车辆合适的角度通过将运动转向为运动传输减速或者提供瞬间加速这个运动来自引擎到车轮去使内外车轮转动不同。开口处的游星齿轮和轮轴是作为单一零件的,但是根据车辆型号有不同的形状。和这个齿轮一起工作的镜面齿轮应该在组装前就磨合好。一旦发生故障,它们应该成对更换。一般来说,在这些系统中齿轮都存在磨损损坏。本文中检查的齿轮损坏具体说是轮轴断裂。本研究进行了差速器小齿轮轴的失效分析。首先,取得材料的机械特点,然后确定其微观结构和化学成分,还要做一些显微镜观察研究来评估其疲劳和破损状况。关键词差速器破损;动力分配装置;小齿轮轴简介最终传动齿轮可能直接或间接地由齿轮箱的输出齿轮驱动。当引擎和传输设备结合在一起,形成统一结构时,就需要使用直接驱动的最终传动齿轮。间接驱动最终传动齿轮或者借助一些装置附在汽车后端,或者并入后桥壳。最终驱动齿轮由于如下原因被使用在传输系统中A为了使齿轮箱或者传动轴的动力90转向B为了提供引擎和驱动轮之间永久的齿轮减速。在汽车中,差速器是将运动从引擎传输到车轮的主要部件。在平坦的道路上,运动会平均分配给两个轮子。内侧车轮应该程度小一些外侧车轮转向程度应该大一些这样转弯才不会侧滑。差速器通常置于后桥中部,由游星齿轮、镜面齿轮、差速器箱、轴齿轮和两个游星蜘蛛齿轮构成。图表一是差速器的示意图,图表二是断裂的小齿轮轴的技术图解,图表三是断裂的小齿轮轴的图片,表示出了断裂部分。在差速器里,人们生产时将镜面和流星齿轮制作得相互适应,并且使用相同的序列号。出现问题的话,二者都要更换。在这些系统中,常见的损伤是齿轮磨损。本研究检查了一辆小型巴士的差速器小齿轮轴。该小型巴士是后轴驱动的柴油汽车,可搭载15名乘客。发动机最大功率是,最大扭转力是。传动箱里有手动系统5个向前,一个向后。损伤是由巴士在交通灯出停止和启动引起的。在差速器中,驱动流星齿轮的输入轴断裂。人们做了各种各样的研究来确定这种损伤的类型和可能的原因。它们是确定轮轴材料的研究确定微观结构的研究与断裂面相关的研究图四是断裂表面和断裂区域的近距离照片。这个断裂是将表面中心的圆形标记齿轮取走形成的。W图1进行分析的差速器的图解图2进行分析的小齿轮轴的技术图解图3研究中进行分析的完好小齿轮轴的图片图4失效轮轴的照片W实验步骤从轮轴中取得的样本要接受各种各样的测试,包括硬度测试,金相和扫描电子显微镜以及化学成分的确定。左右测试均在室温下进行。化学和冶金分析断裂差速器材料的化学分析是使用光谱仪完成的。该材料的化学成分如表一所示。化学成分显示该材料是美国钢铁协会8620型的一种低合金碳化钢。这种钢的淬硬性很低,因为碳含量比例较低。因而,需要通过渗碳处理增加表面区域的碳比例,使表面区域变得坚硬,非常耐用,内部区域变得坚韧。这种钢一般用在需要扭转和弯曲的机械部件中。通过使表面变硬,用残余应力使表面获得高阻力性,获得高疲劳承受值。合金元素怎样掺入碳钢主要取决于每种元素的化合倾向和形成碳化物的倾向。镍溶解于钢的铁酸盐,因为它比铁更不容易形成碳化物。硅与钢中的氧在一定程度上结合形成非金属内含物,不然的话则溶于铁酸盐。铬比铁更容易形成碳化物一些,会在铁酸盐和碳化物阶段之间分解。掺入铬取决于碳含量以及是否没有钛、钶这样更易形成碳化物的元素存在。如果有足够的碳并且没有钛、钶这样更易形成碳化物的元素存在,钨和钼可以和碳形成碳化物。锰和镍可以降低共析混合物的温度。失效差速器材料的初步微观检验如图五所示。可

温馨提示

  • 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
  • 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
  • 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
  • 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
  • 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
  • 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
  • 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

评论

0/150

提交评论