汽车底盘构造-变速器

汽车底盘构造——

变速器与分动器主讲孟庆雨

第一节变速器的功用和类型

功用：（1）改变传动比，扩大驱动轮转矩和转速的变化范围，以适应经常变化的行驶条件，使发动机在有利的工况下工作。（2）在发动机旋转方向不变的前提下，使汽车倒退行驶。（3）利用空档中断动力传递，以使发动机能够起动、怠速，并便于变速器换档或进行动力输出。1.变速器的功用和组成2.变速器的类型1）按传动比变化方式不同：有级式变速器；用齿轮传动，有若干个定值传动比优点：效率高、结构简单、制造容易、工作可靠、维修容易、成本低缺点：１）频繁换档２）车辆的动力性和经济性差３）车辆的行驶性能差４）车辆的行驶平顺性和机件寿命低无级式变速器：采用电力或液力变矩器传动，传动比可在一定的数值范围内连续变化。优点：没有换档动作，方便，没有换档的顿挫感，传动效率高（比自动变速（85%左右）高很多（约95%），与手动变速接近），所以加速快，油耗低缺点：故障率相对较高，成本相对较高，不能用于高输出发动机。综合式变速器：由液力变矩器和行星齿轮式变速器组成，传动比可在几个范围内连续变化。2）按操纵方式不同：强制操纵式：靠驾驶员直接操纵变速杆换档。自动操纵式：换档自动进行。

半自动操纵式：常用的几个档位自动操纵；预选式

第一节变速器的功用和类型变速器组成变速传动机构：改变转速比、改变转矩、改变方向操纵机构：实现换档3.变速器的组成第一节变速器的功用和类型输入轴中间轴输出轴倒档轴变速齿轮结合套壳体第二节变速器的变速传动机构变速传动机构（按传动齿轮轴数）三轴式齿轮变速传动两轴式齿轮变速传动一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

第二节变速器的变速传动机构1.变速传动机构的组成

变速传动机构主要由齿轮、轴及变速器壳体等零部件组成。

输入轴中间轴输出轴倒档轴变速齿轮结合套壳体一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

2.变速传动机构的工作原理

1）利用不同齿数的齿轮对相互啮合，以改变变速器的传动比；

i12=n1/n2=z2/z1=M2/M1z1，n1，M1为主动齿轮的参数。 z2，n2，M2为从动齿轮的参数。从动轮2主动轮1i=主动齿轮齿数从动齿轮齿数第二节变速器的变速传动机构第二节变速器的变速传动机构Gearsareusedtomultiplyeithertorqueorspeedaspoweristransferredfromoneshafttoanother.Inthiscasethegearratiois40÷20or2:1.Thebluegearwillhavetwicethetorquebutone-halfthespeedasthegreengear.Input:20TeethOutput:40TeethGears一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

第二节变速器的变速传动机构ThemostcommongeartypesareSpur(left)andHelical(right)gears.Spurgearshavetheteethcutparalleltotheshaft.Theteethofahelicalgeararecutatanangle.Ahelicalgearrunsquieter,costsmore,andgeneratesasidethrustunderload.SpurGearsHelicalGearsGearTypes一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

第二节变速器的变速传动机构2）通过增加齿轮传动的对数，以实现倒档。一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

第二节变速器的变速传动机构AnIdlergear(orange)canbeputinageartraintoreversedirectionofrotation.Asimpleidler,asshown,willnotchangethegearratio.Inthiscase,thegearratiois40(blueoutputgear)dividedby20(greeninputgear)=2:1,andboththeinputandoutputrotateclockwise.ClockwiseRotationIdlerGear, CounterclockwiseRotationIdlerGears一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

第二节变速器的变速传动机构3．常见的换档方式（1）利用滑动齿轮换档冲击、噪声、损坏齿端面、舒适性降低。倒挡常用。（2）利用接合套换档同时承受换档冲击的齿数多，轮齿不参与换档，不会发生早期损坏。不能消除换档冲击。（3）利用同步器换档迅速、无冲击、无噪声换档；与熟练程度无关。加速性、经济性和行驶安全性提高。一、有级式变速器变速传动机构的组成、工作原理和常见的换档方式

二、两轴式变速器

ManualTransaxleOperation第二节变速器的变速传动机构二、两轴式变速器应用：FFRR特点：输入轴与输出轴平行，无中间轴。组成：输入轴、输出轴、倒档轴、轴承、变速齿轮第二节变速器的变速传动机构

第二节变速器的变速传动机构AmanualtransaxleisusedinmanyFWDvehicles.Itprovidesvariousgearratiosthatarenecessarytotransferpowerfromtheengineandclutchtothedriveshaftsandwheels.ToClutchToDriveshaftPurpose

二、两轴式变速器第二节变速器的变速传动机构Mosttransaxleshavethreemajorshafts: aninputshaftthatconnectstotheclutchdiscwiththedrivinggears, amain/intermediateshaftwiththedrivengears,and theoutputshaftwiththedifferentialInputShaftIntermediateShaftOutput:FinalDrive&DifferentialConstruction

二、两轴式变速器第二节变速器的变速传动机构Apairoftaperedrollerbearings(orange)areusedtosupporteachofthetwomajorshaftsanddifferential.Thistypeofbearingallowstheshafttorotatefreely,buteliminatesanyendplay.Sometransmissionsuseballbearingsforthissamepurpose.优点：直径较小；宽度较大；容量大；可承受高负荷；三元件基本位置关系能使滚子正确对中，轴承可靠性和寿命提高；轴和齿轮的刚度提高，齿轮噪声降低，减少脱档可能。Bearings

二、两轴式变速器SpeedGears&SynchronizersAsynchronizerassemblynormallyhasaspeedgearpositionedoneachsideofit.Thespeedgearsfloatontheshaft.Thesynchronizersleeveengagestheclutchingteethofthespeedgeartotransferitsmotiontotheshaft.1st

4th3rd

Rev.5th2nd

二、两轴式变速器第二节变速器的变速传动机构Oneofthegears,eitherthedrivingordrivengear,foreachgearratioisfixedsolidlytooneoftheshafts.Itmesheswithaspeedgeartoprovidethepropergearratio.Rev.5th2nd1st

4th3rd

二、两轴式变速器FixedGears第二节变速器的变速传动机构第二节变速器的变速传动机构Arathercomplexmechanismconnectsthegearshiftlevertotheshiftforksinsidethetransaxle.Theshiftforksmovethesynchronizersleevestomaketheshiftsfromonegearrangetoanother.ToShiftLeverShiftFork二、两轴式变速器ShiftingGears第二节变速器的变速传动机构Ifeachofthesynchronizersassembliesisinneutralandthereverseidlergearisnotinmesh,powerisnotabletogetfromtheinputshafttotheintermediateshaft.Theinputshaftandthespeedgearscanrotate,buttheintermediateshaftwillnotbedriven.Allsynchros.areinneutral,centerposition二、两轴式变速器Neutral1stGearThisisthelowestgearratiowiththesmallestgearontheinputshaftdrivingthelargestgearontheintermediateshaft.Inthisexamplea12toothgeardrivesa42toothgear. 42÷12=3.501stGear,Driving1stGear,Driven1-2Synchro.,Shiftedto1st二、两轴式变速器第二节变速器的变速传动机构2ndGearThe1-2synchronizerismovedtoengagethe2ndspeedgear.Nowa14toothgeardrivesa35toothgear.Theratiois:35÷14=2.502ndGear,Driving2ndGear,Driven1-2Synchro.,Shiftedto2nd

二、两轴式变速器第二节变速器的变速传动机构3rdGearWiththe1-2synchronizerinneutral,the3-4synchronizerismovedtoengagethe17toothspeedgear.Itdrivesa21toothgear.Theratiois21÷17=1.24:1.3rdGear,Driving3rdGear,Driven3-4Synchro.,Shiftedto3rd

二、两轴式变速器第二节变速器的变速传动机构The3-4synchronizerismovedtoengagethe19toothspeedgearthatisdrivesan18toothgear.Theratiois18÷19=0.95:1.Notethatthisisanoverdriveratiosotheintermediateshaftwillrotatefasterthantheinputshaft.4thGear,Driving4thGear,Driven3-4Synchro.Shiftedto4th

二、两轴式变速器第二节变速器的变速传动机构5thGearThe5thgearsynchronizerismovedtoengagethe15tooth5thspeedgear.Itisdrivenbya20toothgearsotheratiois15÷20=0.75:1,anotheroverdriveratio.5thGear,Driving5thGear,Driven5-RevSynchro.Shiftedto5th二、两轴式变速器第二节变速器的变速传动机构ReverseThe5-Reversesynchro.isshiftedintomeshwiththe42toothRev.speedgear.A12toothRev.Geardrivesit.Theidlergearisusedtochangethedirectionofrotation.Theratiois42÷12=3.50:1Rev.Gear,DrivingRev.Gear,Driven5-Rev.Synchro.ShiftedtoRev.Rev.IdlerGear二、两轴式变速器第二节变速器的变速传动机构OtherReverseTypesSometransaxlesconstructthe1-2synchronizersleevewiththereversegearteethsurroundingit.Thereverseidlergearisshiftedintomeshwiththereversedrivegearandthedrivengearonthesynchro.Sleeve.Thisisdifficulttoillustratebecausetheidlergearandshaftarepositionedbehindtheothergears.Rev.IdlerGearRev.DriveGear1-2Synchro.+1st&2ndSpeedGearsRev.DrivenGearInputShaft二、两轴式变速器第二节变速器的变速传动机构FinalDriveA20toothgearontheintermediateshaftdrivesthe80toothringgearonthedifferential.PoweristransferredfromtheringgeartothedifferentialcaseandthroughthedifferentialgearstotheCVjointsandfrontdriveshafts.Theratiois80÷20=4:1PinionGearRingGearDiff.SideGearDiff.PinionGearCVJoint二、两轴式变速器第二节变速器的变速传动机构OverallRatiosTheoverallratiobetweentheengineandthedrivewheelsiseffectedbybothgearratios.Theseratiosbecome: 1stgear:3.50X4=14:1 2ndgear:2.50X4=10:1 3rdGear:1.24X4=4.96:1 4thGear:0.95X4=3.80:1 5thGear:0.75X4=3:1 Reverse:3.50X4=14:1二、两轴式变速器第二节变速器的变速传动机构第二节变速器的变速传动机构桑塔纳轿车变速器结构简图桑塔纳轿车两轴式变速器结构分析： 一轴：一、二档齿轮与轴一体；三、四档齿轮与轴通过轴承空套轴上。 二轴：一、二档齿轮与通过轴承连接；三、四档齿轮与轴一体。一、二档传动路线三、四档传动路线倒档传动路线

三轴是指汽车前进时，传递动力的轴有第一轴、中间轴和第二轴，直接档除外。三、三轴式变速器第二节变速器的变速传动机构一轴中间轴二轴换档原理第二节变速器的变速传动机构三轴式变速器结构图第二节变速器的变速传动机构挂档方向传动方向结合齿圈结合套齿花键毂跳档方向四、防止自动跳档的措施

原因：利用接合套换档的变速器，由于接合套与齿圈的接合长度较短，同时汽车行驶时需要经常换档，频繁拨动接合套将使齿端发生磨损。汽车行驶中可能会因振动等原因造成接合套与齿圈脱离啮合，即发生自动跳档措施：（1）花键毂齿端的齿厚切薄

第二节变速器的变速传动机构第二节变速器的变速传动机构结合齿圈结合套齿花键毂结合齿圈传动方向（2）齿端制成倒斜面接合套和接合齿圈的齿端制成倒斜面四、防止自动跳档的措施

（3）接合套的齿端形成凸肩

结合套与结合齿圈齿超越结合或两接合齿的接合位置互相错开。挤压磨损形成凸肩，阻止自动退出结合。

四、防止自动跳档的措施第二节变速器的变速传动机构第二节变速器的变速传动机构

五、组合式变速器组合式变速传动机构的特点:由主变速器和副变速器组合（串联）而成为何采用组合式变速传动机构:重型载货汽车的装载质量大，使用条件复杂。欲保证重型车有良好的动力性、经济性和加速性，必须扩大传动比范围并增多档数。为避免变速器结构过于复杂和便于系列化生产，采用组合式变速器，即以四档或五档变速器为主体，通过更换齿轮副和配置不同副变速器(一般为两档)的方法，使变速器获得更多的档数和更宽广的传动比变化范围。第二节变速器的变速传动机构东风重型汽车采用的装有后置副变速器的伊顿RTX-11710B变速器传动机构示意图。该变速器采用了双中间轴结构，动力分流，提高了可靠性，同时缩小了变速器的轴向尺寸(齿轮应力减小-齿宽减小40%)、轴承负荷减小和传动轴的安装倾角。它的主变速器不带同步器，副变速器采用了同步器由前五档主变速器和串联安装在主变速器之后的两档(高速档和低速档)后副变速器组成。可得到10个前进档五、组合式变速器分段式配档第二节变速器的变速传动机构五、组合式变速器五、组合式变速器5-SpeedManualTransmissionPurposeAmanualtransmissionisusedinmanyRWDand4WDvehicles.Itprovidesthevariousgearratiosthatarenecessarytotransferpowerfromtheengineandclutchtothedriveshaftsandwheels.EngineClutchTransmissionDriveshaftDriveAxleConstructionManualtransmissionshavethreemajorshafts: aninputshaft/maindrivegearthatconnectstotheclutchdisc,acountershaftthatiscommonlycalledaclustergear,andthemainshaft/outputshaftwiththedrivengearsandsynchronizers.MainShaftInputShaftClusterGearBearingsThemaindrivegearandmainshaftareeachsupportedbyaballorrollerbearingwithapilotbearingwherethemainshaftfitsintothemaindrivegear.Theclustergearissupportedbyapairofbearings.Thesebearingsarecoloredorange.ClusterGearBearingsMainshaftbearingPilotBearingMainDriveGearBearingSpeedGears&SynchronizersAsynchronizerassemblynormallyhastwospeedgears,oneoneachsideofit.Thespeedgearsfloatonthemainshaft.Thesynchronizersleeveengagestheclutchingteethofaspeedgeartotransferitsmotiontotheshaft.1-2Synchro.3-4Synchro.5-Rev.Synchro.3rdSpeedGear2ndSpeedGear5thSpeedGear1stSpeedGearReverseSpeedGear6-SpeedMainShaft3-4Synchro.1-2Synchro.5-6DrivenGearRev.Synchro.OutputSpeedGearJournals:3rd2nd1stReverseThismainshafthas3splinedareasthatconnecttothesynchronizerhubs,asetofsplinesforthe5-6fixed/drivengear,1setofoutputsplinesforthedriveshaftslipjoint.And4smoothjournalsforthespeedgears.FixedGearsThemaindrivegearandclustergearsarenormallymadeaspartoftheirshaft.Thesearethedrivinggearsforeachofthegearranges.ShiftingGearsMostSUVandpickuptransmissionsincorporatetheshiftmechanismintothethetopoftheunit.Movementofthegearshitleverwillmoveoneoftheshiftforksconnectedtothesynchronizersleeve.ShiftLeverShiftRailShiftForkShiftDetentsMostdetentsarespring-loadedballs(red)thatarepushedintooneoftwoorthreenotchesinashiftrailorcam.Theyareusedtoholdtheshiftrailinanexactpositionwhichplacesthesynchro.sleeveorgearinanexactposition.Thecentershiftraildetentsareinbackoftherail.DetentBallDetentSpringShiftRailShiftForkShiftInterlocksThis5-speedtransmissionhasthreeshiftrailsthattransmitmotionfromtheshiftlevertotheshiftforks.Whenoneoftherailsismovedfromneutral,theplugsaremovedsidewaystolocktheotherrailsinplaceShiftRailsPlugPinPlugNeutralIfeachofthesynchronizersassembliesisinneutralandthereverseidlergearisnotinmesh,powerisnotabletogetfromthespeedgearstothemainshaft.Theinputshaft,clustergear,andspeedgearsrotatebutnotthemainshaft.AllSynchros.Inneutral,centerpositionNeutralInneutralwiththeclutchengaged,theinputshaftwillspin,buttherewillbenopowertransferred.InputfromclutchOutputtodriveshaftNeutralpowerflow5-SpeedgearboxDoubleReductionManualtransmissiongearratiosareeffectedbytwogearsets.Thefirst(input)istheratiobetweenthemaindrivegearandclustergear.Thesecondistheratiobetweenthedriveanddrivengearsforeachgearrange.15ToothMainDriveGear20ToothClusterGear1stGearsInputreduction:20÷15=1.33:1Reduction,1stGears:3:1 1stGearRatio:1.3X3=3.9:11stGearThe1-2synchronizerismovedtoengagetheclutchingteethonthe45tooth1stspeedgear.Itisdrivenbya15toothgearontheclustergear.The1stgearratiois3.9:1.1-2Synchro.Shiftedto1st

1stSpeedGear,Driven1stGear,Driving2ndGearThe1-2synchronizerismovedtoengagethe40tooth,2ndspeedgear.Itisdrivenbya20toothgearontheclustergear.Theclustertomainshaftratiois1.3:1,andthe2ndgearratiois2:1X1.3:1=2.6:1.2ndSpeedGear,Driven2ndGear,Driving1-2Synchro.Shiftedto2nd

3rdGearThe3-4synchronizerismovedtoengagethe20tooth3rdspeedgear.Itisdrivenbea15toothgearontheclustergear.Thegearratiois:1.3:1X1.3:1=1.69:1.3-4Synchro.Shiftedto3rd

3rdGear,Driving3rdGear,Driven4thGearThe3-4synchronizerismovedtoengagetheclutchingteethonthemaindrivegear.Poweristransmitteddirectlytothemainshaftsotheratiois1:1,directdrive.3-4Synchro.Shiftedto4th

MainDriveGearMainShaft5thGearThe5-Rev.synchronizerismovedtoengagethe20tooth5thspeedgear.Itisdrivenbya30toothgearthatispartoftheclustergear.Theratiois0.66:1X1.3:1=0.86:15thGear,Driving5-Rev.SynchroShiftedto5th5thGear,DrivenOther5thGearTypesThe5thdrivinggearinthistransmissionisaspeedgearmountedontheclustergearalongwiththe5thgearsynchronizer.The5thdrivengearisattachedtothemainshaft.5thDrivenGear5thGearSynchronizer5thSpeedGearReverseThe5-Reversesynchro.isshiftedintomeshwiththe45toothRev.speedgear.A15toothRev.gearontheclusterdrivesitthroughtheRev.idlergear.Theidlergearisusedtochangethedirectionofrotation.Thereversegearratiois3:1X1.3:1=3.9:1.5-Rev.Synchro.ShiftedtoRev.Rev.Gear,DrivingRev.IdlerGearRev.Gear,DrivenRev.Gear,DrivenOtherReverseTypesSome4&5speedtransmissionsuseareversedrivengearthatsurroundsthe1-2synchronizersleeve.Thereverseidlergear(mountedbehindtheothergears)isshiftedintomeshwiththereversedrivinggearontheclustergearandthereversedrivengear.Allthreeofthesegearsarespurgears.ReverseDrivenGearReverseDriveGearReverseIdlerGear第三节同步器无同步器时变速器的换档过程1、从低档换入高档脱离瞬间：V4=VJ

V5>VJ、V4保持空档片刻V5降低，VJ、V4变化不大在VJ与V5相等时挂入五档五档齿轮四档齿轮中间轴结合套花键毂结合齿圈2、从高档换入低档脱离瞬间：V5=VJ

V4<VJ、V5抬起离合器踏板，踩一下油门踏板，V4升高，VJ变化不大在VJ与V4相等时挂入四档五档齿轮四档齿轮中间轴结合套花键毂结合齿圈第三节同步器四档工作：V3=V4，欲换档—踩离合器—接合套左移—处空挡因V4<V2V3<V2；为避免齿轮冲击，不能立即换入五档两直线的交点为同步状态，此时挂档不会产生冲击在空挡时：V2下降很快，V3下降缓慢（整个汽车转动惯量大）第二节：同步器（一）低档换高档一、无同步器换档过程tV2V2V3V3t2t3V第三节同步器（二）高档换低档五档工作时：V3=V2，因V2>V4—V3>V4空档时：V4比V3下降得快，直线V3、V4不会有交点，不可能达到自然同步状态，驾驶员应在变速器退到空档后，立即抬起离合器，同时踩加速踏板，使发动机连同离合器和第一轴都从B点升速，让V4>V3，再踩离合器等到V3=V4，可以换档。V3V4t2t3tVBA’AV3V4第三节同步器第三节同步器1、功用：使结合套与待啮合齿圈迅速同步，缩短换档时间，同时防止啮合时齿间冲击。2、结构： 结合套、花键榖、对应齿轮上的结合齿圈、同步装置、锁止装置。3、同步器分类：常压式、惯性式、自增力式惯性式同步器分类：锁环式惯性同步器锁销式惯性同步器二、同步器构造及工作原理第三节同步器二、同步器构造及工作原理第三节同步器1.锁环式惯性同步器二、同步器构造及工作原理r为锁止面平均半径；β为锁止面锁止角;R摩擦锥面平均半径;α锥面半锥角二、同步器构造及工作原理第三节同步器1.锁环式惯性同步器欲保证锁止和滑动齿套不能继续移动，必须满足如下条件细牙螺旋槽滑块1.锁环式惯性同步器二、同步器构造及工作原理第三节同步器滑块锁环结合齿圈第三节同步器定位销、滑块锁环结合齿圈1齿厚第三节同步器环锁环式同步器特点：结构紧凑，径向尺寸小，锥面间产生的摩擦力矩较小锁止面是锁环的接合齿端面，使用中会使齿端磨损而失效，适用于传递转矩不大的轿车和轻型货车的变速器。在中型货车以上的变速器中，尤其是低速档最好采用锁销式惯性同步器。第三节同步器二、同步器构造及工作原理1.锁环式惯性同步器摩擦锥盘摩擦锥环定位销结合套钢球定位销锁销特点：直径较大的摩擦锥面，可产生较大摩擦力矩缩短同步时间。第三节同步器2.锁销式惯性同步器二、同步器构造及工作原理锁止角二、同步器构造及工作原理锁销受力2.锁销式惯性同步器第三节同步器SynchronizerOperationSynchronizersThis5-speedtransaxlehas3synchronizerassemblies.Eachonehasaneutralandtwoothergearpositions.3-4Synchro.Assembly1-2Synchro.Assembly5-RevSynchro.AssemblySynchronizerComponentsInputShaft3-4Synchro.BlockerRingsSpeedGearswithNeedleBearingsThehubofthis3-4synchronizerissplinedontotheinputshaftThe3rdand4thspeedgearsfitovertheneedlebearingsandtheinputshaft.Thisinputshaftalsohasdrivinggearsfor1st,2nd,andreverse.SynchronizerAssembly,ExplodedViewThissynchronizerassemblyhasbeentakenaparttoshowthemajorparts.Mostsynchronizershave3or4struts.EnergizerSpringsHubSleeveKey/Strut/InsertSynchronizerHubThekeys(green)andenergizersprings(red)fitintothehubsothespringswillexertanoutwardpressureonthekeys.Notethesplinesontheinsideofthehubtoconnectwiththeshaft.SynchronizerAssembly,AssembledViewThesleeve(orange)canslideonthehub(grey).Thekeys(green)arepushedoutward,againstthesleevebytheenergizersprings(red).SynchronizerSleeveTwoimportantfeaturesofasynchronizersleevearetheneutraldetentnotcharoundthecenterofthesplinesandthesplinelockbacktaperattheendsofeachspline.Theneutraldetentnotchengagesthehumponthekeys.Acompleteshiftplacesthebacktaperalongsideoftheclutchteethbacktaper.BackTaperNeutralDetentNotchSpeedGearsAspeedgearhasteeth(blue)thatdriveoraredrivenbyanothergear.Italsohasclutchingteeth(green)thatengagethesynchronizersleeve,asmoothconesurface(orange)fortheblockerring,andasmoothinnerbore(yellow)forthegeartorotateon.ClutchingTeethConeBlockerRingsAblockerringisalsocalledasynchronizerringorstopring.A1-piece,metalblockerringisusedinmostoldertransmissions.Notethegrooves(circled)andthreadsontheinnersurfacetoremovethelubricantfromthespeedgearcone.Theblockerringfloatsinthesynchronizerassemblyandisdrivenbythekeys,positionedinthethreenotches(red,triplearrow).3-PieceBlockerRingsOuterBlockerRingIntermediateConeSpeedGearInnerBlockerRingSomemoderntransmissionsusepaper-linedblockerringsforbettershifting.Theseare3-pieceunits.Theinnerandouterblockerringsareattachedtoeachotherandthesynchronizer.Theintermediateconeisattachedtothespeedgear.Thesetransmissionsusuallyrequireaspeciallubricant.BlockerRingOperationWhenthesleeveisshiftedtotheleft,thekeywillmovewithit.Afterasmallamountofmovement,thekeywillpushtheblockerringagainstthespeedgearcone,andtheblockerringwilltrytorotatewiththespeedgear.Notehowmuchbiggertheblockerringnotchisthanthekey;thisallowsthekeytorotateslightlytoblockthesleeve.SpeedGearSleeveBlockerRingKeyHubEnergizerSpringOperationDuringShiftSpeedGearTravelSleeveSplineMovementBlockerRingMovementSleevemovementatthebeginningofashift,movestheblockerringtocontactthespeedgearcone.Theblockerringthenrotatesslightlysoitsteethareblockingthesplinesinthesleeve.Furthershiftpressurepushestheblockerringagainstthespeedgearcone.Thisslowsthespeedgeartothesamespeedasthesynchronizer.CompletedShiftAfterthespeedgearslowsdown,theblockerringsmovesaside,andthesleevecanmoveovertheclutchteeth.Theshiftiscompletewhenthebacktapersaresidebysideasshowninthecenter.SpeedGearSleeveBackTapersClutchingTeethBackTaperThissectionofaspeedgearshowshowthebacksideoftheclutchingteeth(lightblue)aretaperedtobecomenarrower.Thistaperholdsthesynchronizersleeveinplaceandpreventsgear“jumpout”.第四节变速器操纵机构功用： 保证驾驶员能准确可靠地使变速器换入某个档位。要求： 自锁功能：防止自动换档、脱档。 互锁功能：保证变速器不会同时换入两个档位。 倒档锁：防止误换倒档。分类： 直接操纵式 远距离操纵式ShiftingGearsMostSUVandpickuptransmissionsincorporatetheshiftmech