载货汽车主减速器外文文献翻译、中英文翻译

附录TruckMainReductionGearInthehighlycompetitiveperiodfollowingtheenergycrisisoftheearly1970's,theautomotiveindustryhadtoshiftattentionincreasinglytowardsimprovementofthequalityoftheproduct,yetstillkeepingitspricesaslowaspossible.PriortothatGKNAxlesLtd,totakeoptimumadvantageofeconomiesofscale,hadbeenproducingathighlycompetitivepricesastandardrangeofaxlesofdifferenttypesandsizes,fromwhichallcustomers'needscouldbesatisfied.Becausevehiclemanufacturershadnothithertohadtoplacesuchagreatemphasisonfueleconomy,andthereforeonlightweight,thesestandardaxlescouldcaterreliablyforallconditionslikelytobemetinawidevarietyofapplications.Nowvehiclemanufacturersrequireaxlesdesignedanddevelopedfortheirspecificapplications.Asaxledesignisbecomingincreasinglyspecialised,customersareincreasinglyraisingtheiraspirationsintermsofperformanceanreliability.Forthisreason,theyareturningtospecialistssuchasGKNAxlesLtdwhohavetheabilitytoprovideaxlesforawidevarietyofvehicles。Sincethe1970s,however,incommonwithvirtuallyallothersupplierstothehighvolumeproducersinthemotorindustry,GKNhasradicallymodifieditsapproachtosuittheprevailingconditionsastheychangethroughthe1980sandonintothe1990s.Itsaimnowisatsupplyingcompleteaxleassembles,including,forexample,thebrakes,alldesignedandfullydevelopedforandintegrated,asamatterofcourse,intospecificvehicledesignsincluding,inparticular,thoseforthespecialistmarket.

Emphasisisnowonrationalizationofmaterials,methodsandcomponents.Thisoverallchangehasbeennecessarybecauseofthegreatlyincreasedsophisticationdemandedofthemodernvehicle,intermsofoverallefficiency,compactness,lightweight,reliability,durability,refinementandmaintenance-freeoperation.AnotherareaintowhichGKNAxleshasexpandedisthesupplyofcomponentsandassembliessuchaslimited-slipdifferentials,ball-joints,transferboxes,gearsandsometypesofsuspension.

Foroff-roadoperation,thedutycyclesmaybeentirelydifferentinbothtorsionalandbeamloading-denpendingontheapplication.Forexample,sometypesofvehiclespendaconsiderableproportionoftheirrunningtimeathightorqueinlowgear.Inmostcircumstances,theterrainmaybesuchthatthetyrestendtoslipmorereadilythanontarmac;inothers,however,forexampleinfairlyfirmsandyscrees,itmayallowtyrestobiteintoit,andthusleadtotorsionalfatigueloadingsignificantlygreaterthanonsmoothroads.Verticalandlateralloading,too,maybemuchmoresevere,thoughthisdosedependtoamajorextentonspeeds.Shockloadingcanalsoaffectbrakingandaccelerationtorquesthough,again,sucheffectsarespeed-dependent.

Hypoidgearsystemsaremorecommonlyusedthanspiralbevels.Theirprincipleadvantagesarethatpinionsofaspecificratioarebigger,theirteethprofilesareoflargeradius,theyareinherentlystrongerandmoredurable,theirmeshingareasarelarger,andtheygeneratelessnoise

Hostreductiongeareffectistobeusedtoreducetherotationratethatthetransmissionshaftsendsinbuttoenhancerevolutionmomentoftorsion,changesdrivedirectionwithmomentoftorsion,passesontohalfaxesafterdifferentialmechanismand.Thehostreductiongearstructureformisthattheformisdifferentbutdifferentaccordingtogearwheeltype,reductiongearmainly.Hostreductiongeargearwheelhashelixconeformssuchasgearwheel,hypoidgear,columngearwheelandwormgearwormmainly.Pairoflevelhostreductiongeariscomparedwithsinglestage,thegapmaybe7~12transmissionratio,i0eachotheratthesametimeinsweartobeawayfromafield12.Butthedimension,massarewithoutexceptionbigger,costishigher.Itappliestomiddle,heavytypefreighttrain,go-anywherevehicleandmotorbusmainlygoahead.Dyadicoverallpairoflevelhostreductiongearhasthevariousstructurescheme:Firstorderisaconegearwheel,thesecondstageisacolumngearwheel;Firstorderisaconegearwheel,thesecondstageisepicyclicgear;Firstorderisepicyclicgear,thesecondstageisaconegearwheel;Firstorderisacolumngearwheel,thesecondstageisaconegearwheel.Horizontal,askew,faceanddroopovertothethreekindstofirstorderfortheconegearwheel,thesecondstagearethatpairofcolumngearwheellevelbetokensreductiongear,buthasdirectionarrangementscheme.Directionlevelarrangementcanusetheassemblydroopingovertooutlinedimensiondiminution,reducingtheautomobilequalityheartaltitudethereby,makesthedirectiondimensionincreasebybut,thattheuseonlongdistancebetweenshaftsautomobilebutappropriatediminutiontransmissionshaftlength,isharmfulforshortdistancebetweenshaftsautomobile'stoputarrangementtogetherbut,maymakeatransmissionshaftshort,leadstoauniversaltransmissionshaftintersectionangleenlarge.Droopovertoarrangingamessengertodrivethebridgedirectiondimensiondiminution,maydiminishauniversaltransmissionshaftintersectionangle,sincebuthostreductiongearshellfixessuperjacentinbridgeshell,makenotonlydroopoverenhancetooutlinedimension,andhavereducedbridgeshellstiffness,havebeenharmfulforgearwheeltowork.Thisarrangementbuteasytobeversedinstyledrivingabridgearrangement.Arrangingbridgeshellstiffnessandimprovingtothetransmissionshaftisslantingtoarrangementadvantageous.Whenassigningatransmissionratioinpairoflevelhostreductiongearhavingtheconegearwheelandthecolumngearwheel,thecolumngearwheelis1.4~liketheratioauxiliaryandboringsubsidiarygearwheeltransmissionratio2.0,andtheconegearwheelis1.7~likesubsidiarytransmissionratio3.3,suchaxialloadingmaydiminishaconewhenthegearwheelisengagedandeffectloadingonthedrivenconegearwheelandthecolumngearwheel,maymaketheactiveconegearwheeltoothnumberappropriateincreasingbyatthesametime,makewhosesupportingaxisneckdimensionappropriateenlarge,Toimprovewhosesupportingstiffness,improvefalling-instationarityandthejobreliability.

Formodernaxles,choiceofgearlubricantcanbecritical.Incarsoperatingathighspeedsonmotorways,axleoiltemperaturecanultimatelyriseevenhigherthan130℃,soventingofthecasingisimportant.Inprinciple,theoilinthebaseofthecastingissweptaroundoverthecrownwheelandthenforwardsthroughthetwobearingsthatcarrythepinion.Consequently,boththeshapesanddimensionsoftheclearancesbetweenthecrownwheelandcasingcanbecritical,andadequatedrainagehastobeprovidedfortheoiltoflow,throughchannelscoredinthepinionbearinghousings,backtothebaseofthecasing.

Withinthegearcarrierunit,taperrollerbearingsareemployedalmostuniversallyforcarryingtheinputpinion.Theyhavealargeloadcapacitywithinasmallenvelope,andcanbepreloadedforaccurateandstablepositioningofthegears.Forpinionflangesealswhereresistancetohightemperaturesatrelativelyhighspeedsisessential,polyarcylatemaybespecified,buttheabrasiveconditionsVitonisgenerallypreferred.Thattheconegearwheeltoothgoesoverwidthfacetofacecannotenhancegearwheelintensityandlife-span,isabletoleadtotoothditchunexpectedturnofeventssmallendbecauseofconegearwheelgearteethonthecontrarynarrowthecuttingknifethetopoftheheadfacewidtharousingistoonarrowandthepointofakniferoundangleistoosmall.Likethis,notonly,havediminishedthetoothradicalcircleradius,haveenlargedstrainalltogether,lifetimehavingreducedacutter.Besides,whenassembling,havelocationdeviationorwaitforcausesincefabrication,heattreatmentaredeformable,loadingconcentratesminoringearteethendwhenmakingagearwheelwork,isabletoarousegearteethholdinguntimelydamageandwearylossforashorttime.Thatbesides,thetoothgoesoverwidthfacetofacealsoisabletoarouseassemblingspacediminution.Theflankofatoothistoonarrowbut,thegearteethoutsideabrasionresistancemeetingreduces.Fortherunning-inimprovingthenewgearwheel,preventthepersonfromdyinginworkingtoModelTwearappearoninitialstage,bruising,gluingtogetherorbarking,conegearwheelbonderizingbeing0.005~0.020mminheattreatmentandfinishmachiningaftercrop,thicknesshandlesorthecopperfacing,thetinplatinghandle.Theballcarryingoutstrainontheflankofatoothgushingissoldatreducedprices,mayimprove25%'sgearwheellife-span.Tothehighspeedgearwheelsliding,maybeinprogressasulfuroozinghandlingtoimproveabrasionresistance.Rubafactorbutnotablesulfurqueenlesseningoozes,eveniflubricatingconditionisrelativelypoor,also,canpreventtheflankofatoothbruisefromfacing,barkstodieandgluetogether.载货汽车主减速器

在能源竞争激烈的二十世纪七十年代初，汽车业不得不将注意力越来越多地定格在改进产品的质量上，但仍然维持其价格尽可能低。在此之前，吉凯恩车桥有限公司占据最佳经济规模的优势，在价格允许范围内生产极具竞争力的不同类型车轴，使所有客户的需求可以得到满足。但由于汽车制造商并没有经历过这样一个非常注重燃油经济性的时期，因此，对重量轻的要求，这些标准车轴似乎可满足所有条件，满足各种各样的应用。现在汽车制造商需要车轴设计和开发的具体应用。轴设计正变得越来越专业化，在性能的可靠性方面，客户越来越多地提高自己的期望。出于这个原因，他们在找一个能提供各种车辆轴的公司。然而自二十世纪七十年代以来，在几乎所有其他汽车行业供应商的技术里，GKN从根本上改变了它的办法，以适应当前的条件，他们在二十世纪八十年代和九十年代的生产目的是提供完整的轮轴安装，其中包括，刹车、所有的设计和整合、具体的汽车设计，以及为专业市场特别设计的。

现在的重点是合理化的材料，方法和内容。总的改革是必要的，对于复杂性很大的现代汽车，考虑总体效率，紧凑，重量轻，可靠性，耐用性，完善和免维护运行。另一个领域，GKN提供的车轴是扩大了供应的部件和组件，如限滑差速器，球关节，齿轮和某些类型的悬挂架。

对于越野车，某些车辆设计公司花费了相当多的时间在较低齿轮但高扭矩的设计上。在大多数情况下，地形可能使这样的轮胎打滑。例如，在相当坚硬的沙质路面，它可能允许轮胎咬进去，从而使扭转疲劳显著大于在平稳的道路行驶。虽然在大程度上这取决于速度，但纵向和横向打滑时将更严重。冲击负荷也会影响刹车和加速扭矩，这种影响是取决于速度的。准双曲面齿轮传动是锥齿轮传动中的普遍形式，螺旋锥齿轮是它的一种特殊情况。他们的优点是齿轮的具体比例较大，其啮合区较大，而且低噪音,他们本质上是更强大，更持久和更耐用。主减速器的作用是用来降低传动轴传来的转速而增大旋转扭矩，并将扭矩改变传动方向，经差速器传给半轴。主减速器的结构形式主要是根据齿轮类型、减速器形式不同而不同。主减速器的齿轮主要有螺旋锥齿轮、双曲面齿轮、圆柱齿轮和蜗轮蜗杆等形式。双级主减速器与单级相比，在保证离地间隙