外文翻译--手动变速器如何工作.docx

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1、附录HowManua1TransmissionsWorkIfyoudriveastick-shiftcar,thenyoumayhavesevera1questionsf1oatinginyourhead.Howdoesthefunny,HpatternthatIammovingthisshiftknobthroughhaveanyre1ationtothegearsinsidethetransmission?WhatismovinginsidethetransmissionwhenImovetheshifter?WhenImessupandhearthathorrib1egrindingso

2、und,whatisactua11ygrinding?Whatwou1dhappenif1weretoaccidenta11yshiftintoreversewhi1eIamspeedingdownthefreeway?Wou1dtheentiretransmissionexp1ode?Inthisartic1e,we11answera11ofthesequestionsandmoreasWeexp1oretheinteriorofamanua1transmission.Carsneedtransmissionsbecauseofthephysicsofthegaso1ineengine.Fi

3、rst,anyenginehasared1ineamaximumrpmva1ueabovewhichtheenginecannotgowithoutexp1oding.Second,ifyouhavereadHowHorsepowerWorks,thenyouknowthatengineshavenarrowrpmrangeswherehorsepowerandtorqueareattheirmaximum.Forexamp1e,anenginemightproduceitsmaximumhorsepowerat5,500rpm.Thetransmissiona11owsthegearrati

4、obetweentheengineandthedrivewhee1stochangeasthecarspeedsupands1owsdown.Youshiftgearssotheenginecanstaybe1owthered1ineandneartherpmbandofitsbestperformance.Idea11y,thetransmissionwou1dbesof1exib1einitsratiosthattheenginecou1da1waysrunatitssing1e,best-performancerpmva1ue.Thatistheideabehindthecontinuo

5、us1yvariab1etransmission(CVT).ACVThasanear1yinfiniterangeofgearratios.Inthepast,CVTscou1dnotcompetewithfour-speedandfive-speedtransmissionsintermsofcost,sizeandre1iabi1ity,soyoudidn,tseetheminproductionautomobi1es.Thesedays,improvementsindesignhavemadeCVTsmorecommon.TheToyotaPriusisahybridcarthatuse

6、saCVT.Thetransmissionisconnectedtotheenginethroughthec1utch.Theinputshaftofthetransmissionthereforeturnsatthesamerpmastheengine.Afive-speedtransmissionapp1iesoneoffivedifferentgearratiostotheinputshafttoproduceadifferentrpmva1ueattheoutputshaft.AVerySimp1eTransmissionTounderstandthebasicideabehindas

7、tandardtransmission,thediagrambe1owshowsaverysimp1etwo-speedtransmissioninneutra1:1ets1ookateachofthepartsinthisdiagramtounderstandhowtheyfittogether:Thegreenshaftcomesfromtheenginethroughthec1utch.Thegreenshaftandgreengearareconnectedasasing1eunit.(Thec1utchisadevicethat1etsyouconnectanddisconnectt

8、heengineandthetransmission.Whenyoupushinthec1utchpeda1,theengineandthetransmissionaredisconnectedsotheenginecanrunevenifthecarisstandingsti11.Whenyoure1easethec1utchpeda1,theengineandthegreenshaftaredirect1yconnectedtooneanother.Thegreenshaftandgearturnatthesamerpmastheengine.)Theredshaftandgearsare

9、ca11edtheIayshaft.Thesearea1soconnectedasasing1epiece,soa11ofthegearsontheIayshaftandtheIayshaftitse1fspinasoneunit.Thegreenshaftandtheredshaftaredirect1yconnectedthroughtheirmeshedgearssothatifthegreenshaftisspinning,soistheredshaft.Inthisway,theIayshaftreceivesitspowerdirect1yfromtheenginewhenever

10、thec1utchisengaged.Theye11owshaftisasp1inedshaftthatconnectsdirect1ytothedriveshaftthroughthedifferentia1tothedrivewhee1softhecar.Ifthewhee1sarespinning,theye11owshaftisspinning.Theb1uegearsrideonbearings,sotheyspinontheye11owshaft.Iftheengineisoffbutthecariscoasting,theye11owshaftcanturninsidetheb1

11、uegearswhi1etheb1uegearsandtheIayshaftaremotion1ess.Now,1et,sseewhathappenswhenyoushiftintofirstgear.FirstGearInthispicture,thegreenshaftfromtheengineturnstheIayshaft,whichturnstheb1uegearontheright.Thisgeartransmitsitsenergythroughtheco11artodrivetheye11owdriveshaft.Meanwhi1e,theb1uegearonthe1eftis

12、turning,butitisfreewhee1ingonitsbearingsoithasnoeffectontheye11owshaft.Whentheco11arisbetweenthetwogears(asshowninthefirstfigure),thetransmissionisinneutra1.Bothoftheb1uegearsfreewhee1ontheye11owshaftatthedifferentratescontro11edbytheirratiostotheIayshaf1.Fromthisdiscussion,youcananswersevera1questi

13、ons:Whenyoumakeamistakewhi1eshiftingandhearahorrib1egrindingsound,youarenothearingthesoundofgearteethmis-meshing.Asyoucanseeinthesediagrams,a11gearteetharea11fu11ymeshedata111imes.Thegrindingisthesoundofthedogteethtryingunsuccessfu11ytoengagetheho1esinthesideofab1uegear.Thetransmissionshownheredoesn

14、othave,synchros,(discussed1aterintheartic1e),soifyouwereusingthistransmissionyouwou1dhavetodoub1e-c1utchit.Doub1e-c1utchingwascommonino1dercarsandissti11commoninsomemodernracecars.Indoub1e-c1utching,youfirstpushthec1utchpeda1inoncetodisengagetheenginefromthetransmission.Thistakesthepressureoffthedog

15、teethsoyoucanmovetheco11arintoneutra1.Thenyoure1easethec1utchpeda1andrevtheenginetotherightspeed.1Therightspeedistherpmva1ueatwhichtheengineshou1dberunninginthenextgear.Theideaistogettheb1uegearofthenextgearandtheco11arrotatingatthesamespeedsothatthedogteethcanengage.Thenyoupushthec1utchpeda1inagain

16、and1ocktheco11arintothenewgear.Ateverygearchangeyouhavetopressandre1easethec1utchtwice,hencethenamedoub1e-c1utching.Youcana1soseehowasma111inearmotioninthegearshiftknoba11owsyoutochangegears.Thegearshiftknobmovesarodconnectedtothefork.Theforks1idestheco11arontheye11owshafttoengageoneoftwogears.Inthenextsection,we11takea1ookatarea1transmission.ARea1TransmissionTherearethreeforkscontro11edbythreerodsthatareengagedbytheshift1ever.1ookin