自動變速器-畢業(yè)論文外文翻譯

1、AUTOMATICTRANSMISSIONThemodernautomatictransmissionisbyfar，themostcomplicatedmechanicalcomponentintoday’sautomobile.Itisatypeoftransmissionthatsiftsitself.Afluidcouplingtqueconverterisusedinsteadofamanuallyoperatedclutch

2、toconnectthetransmissiontotheengine.Therearetwobasictypesofautomatictransmissionbasedonwhetherthevehicleisrearwheeldrivefrontwheeldrive.Onarearwheeldrivecar，thetransmissionisusuallymountedtothebackoftheengineislocatedund

3、erthehumpinthecenterofthefloboardalongsidethegaspedalposition.Adriveshaftconnectsthetransmissiontothefinaldrivewhichislocatedintherearaxleisusedtosendpowertotherearwheels.Powerflowonthissystemissimplestraightfwardgoingfr

4、omtheengine，throughthetqueconverter，thentroughthetransmissiondriveshaftuntilitreachesthefinaldrivewhereitissplitsenttothetworeartransmission.Onafrontwheeldrivecar，thetransmissionisusuallycombinedwiththefinaldrivetofmwhat

5、iscalledatransaxle.Theengineonafrontwheeldrivecarisusuallymountedsidewaysinthecarwiththetransaxletuckedunderitonthesideoftheenginefacingtherearofthecar.Frontaxlesareconnecteddirectlytothetransaxleprovidepowertofrontwheel

6、s.Inthisexample，powerfloesfromtheengine，throughthetqueconvertertoalargerchainthatsendsthepowerthrougha180degreeturntothetransmissionthatisalongsidetheengine.Fromthere，thepowerisroutedthroughthetransmissiontothefinaldrive

7、whereitissplitsenttothetwofrontwheelsthroughthedriveaxles.Thereareanumberofotherarrangementsincludingfrontdrivevehicleswheretheengineismountedfronttobackinsteadofsidewaysthereareothersystemsthatdriveallfourwheelsbutthetw

8、osystemsdescribedherearebyfarthemostpopular.Amuchlesspopularrearisconnectedbyadriveshafttothetqueconverterwhichisstillmountedontheengine.ThissystemisfoundonthenewCvetteisusedindertobalancetheweightevenlybetweenthefrontre

9、arwheelsfimprovedperfmancehling.Anotherreardrivesystemmountseverything，theengine，transmissionfinaldriveintherear.ThisrearenginearrangementispopularonthePsche。pack.Surroundingtheoutsideofthedrumisabthatcanbetightenedaroun

10、dthedrumwhenrequiredtopreventthedrumwiththeattachedsungearfromturning.Theclutchpackisused，inthisinstance，tolocktheplacarrierwiththesungearfcingbothtoturnatthesamespeed.Ifboththeclutchpackthebwerereleased，thesystemwouldbe

11、inneutral.Turningtheinputshaftwouldturntheplagearsagainstthesungear，butsincenotingisholdingthesungear，itwilljustspinfreehavenoeffectontheoutputshaft.Toplacetheunitinfirstgear，thebisappliedtoholdthesungearfrommoving.Toshi

12、ftfromfirsttohighgear，thebisreleasedtheclutchisappliedcausingtheoutputshafttoturnatthesamespeedastheinputshaft.Manymecombinationsarepossibleusingtwomeplaarysetsconnectedinvariouswaytoprovidethedifferentfwardspeedsreverse

13、thatarefoundinmodernautomatictransmission.2）ClutchpackAclutchpackconsistsofalternatingdisksthatfitinsideaclutchdrum.Halfofthedisksaresteelhavesplinesthatfitintogrovesontheinsideofthedrum.Theotherhalfhaveafrictionmaterial

14、bondedtotheirsurfacehavesplinesontheinsideedgethatfitgrovesontheoutersurfaceoftheadjoininghub.Thereisapistoninsidethedrumthatisactivatedbyoilpressureattheappropriatetimetosqueezetheclutchpacktogethersothatthetwocomponent

15、sbecomelockedturnasone.3）OnewayClutchAonewayclutch(alsoknownasa“sprag”clutch)isadevicethatwillallowacomponentsuchasringgeartoturnfreelyinonedirectionbutnotintheother.Thiseffectisjustlikethatbicycle，wherethepedalswillturn

16、thewheelwhenpedalingfward，butwillspinfreewhenpedalingbackward.Acommonplacewhereaonewayclutchisusedisinfirstgearwhentheshifterisinthedriveposition.Whenyoubegintoacceleratefromastop，thetransmissionstartsoutinfirstgear.Buth

17、aveyouevernoticedwhathappensifyoureleasethegaswhileitisstillinfirstgearThevehiclecontinuestocoastasifyouwereinneutral.Now，shiftintoLowgearinsteadofDrive.Whenyouletgoofthegasinthiscase，youwillfeeltheengineslowyoudownjustl