农用拖拉机车辆外文文献翻译、中英文翻译、外文翻译

1、FARMTRACTORThehistoryoftractordevelopmentistolangtorelatehere.LandmarksalongtheroadincludethefiresuseofaninternallcombustionengineStatesin1890;the'Ivel'Fordof1917,andtheInternationalDuringthe1930s,theuseoflowsoonbecamepopular,andtheinatractorintheUnitedtractorof1901;theAmerican'Farmall&#

2、39;of1923.-pressurepneumatictyresfirstFergusonsystemtracrorsincorporatingthree-pointlinkagewithhydraulicdraughtcontrolwereintroduced.Classificationoftractortypes.Tractorsasnowmanufacturedcanbeclassifiedasfollows:A. Accordingtomethodofsecuringtractionandself-propulsion:1. Wheeltractorsa. Threetractor

3、sb. Fourwheels2. Track-typetractorsB. Accordingtoutility:1. General-purposeorutility2. All-purposeorrow-croptypeWheeltractors.Thewheel-typetractoristhepredomingatingtype,particularlyforagriculturalpurposes.Wheeltractorsaremadeeitherwiththreewheelsorwithfourwheels.Theusualarrangementconsistsoftworear

4、-drivewheelsandoneortwofrontsteeringmembers.Track-typetractors.Thetractionmechanisminthetrack-typetractorconsistsessentiallyoftwoheavy,endless,metal-linkeddevicesknownastracksthemselvesbyreducingthemovementofonetrackbelowthespeedoftheother.General-purposeorutilitytractor.Ageneral-purposetractorisone

5、ofmoreorlessconventinaldesignsuchasanordinaryfour-wheelmachineoratrack-typemachine.Thistypeisalsoreferredtoasautilitytroctor.Itismadetoperformonlytheusualtractorjops,includingbothfieldandbeltworksuchasplowing,harrowing,roadgrading,combining,feedgrinding,andthelike.All-purposetractors.Anall-purposeor

6、row-croptypeisatractordesignedtohandlepracticallyallthefieldandbeltjopsontheaveragefarm,includingtheplantingandintertillageofrowcrops.Theconventionaltractorconsistsbasicallyoftwoengine-driwenwheels,usuallyattherear,andtwosupportwheelsstthefront.Thetypeoftheengineusedtopowertheheartofthetractor;itish

7、erethatthefuel,thechemicalpotentialenergy,isconvertedintothemechanicalemergywhichcausesthewheelstoturn.Thedifferencebetweenninternalandexternalcombustionengineissimplythatinaninternalcombustionengine,theconversionofpotentialenergyintomechanicalenergytakesplacewhollyinthecylinder,whereaswithexternalc

8、ombustionthefuelisburntoutsidethecylinder.Asteamengineoragasturbineisagoodexampleofthelatter.Howcanliquidfuelbechangedintorotationalmechaanicalenergy?Thisisachievedbyaccuratelymixingthefuelwithairandthenburningitincontrolledcondition.Whenthismixtureburns,itexpandsandpressurebuildsupforcingthepistont

9、omovedownthecylinderinastraightline.Itissaidtorotarymotion.Thislinearmotionisconvertedintorotarymotionbyaconnectingrodandcrankarrangementjoinedtothepiston.Tobeabletousethisenergyeffectively,theburningandcombustionproceandtheforceofexpansionhavetobecontrolled.Todothis,theenginemusthave:1. Atubeorcyli

10、nderclosedatoneend,inwhichthemixtureoffuelandaircanbecompressedandburnt.2. Apiston,whichslidesfreelyandyetfitscloselyinthecylinder,sothattheexpandinggasforceitdownthecylinder,anddonotescapepastit.3. Twopassagesorportsinthecylinder.Oneforthemixtureoffuelandairtoenterthecylinder,theinletprot,andtheoth

11、ertoallowtheusedgasestoescape,theexhaustport.4. Twovalves,theinletvalvetocontrolthethemovementofthemixturetothecylinder,andtheexhaustvalvetocontroltheescapeoftheusedgases.Bycarefullytimingtheignitionofthemixtureinrelationoftheopeningandclosingofthevalvesandthepositionofthepiston,itispossibletomaketh

12、epistonmoveupanddownthecylindercontinuously.Theworkingofaninternalcombusitionengine,onceitisstarted,involvesasequenceorcycleofoperationsineachcycleandthetwo-strokecycle.Inthefour-strokecycle,thecrankshaftcompletestworevolutionsandthepistonfourstrokes,astrokebeingthemovementofthepistonfromoneendofthe

13、cylindertotheother.Inthetwo-strokecycle,thecrankshaftmakesonerevolutionandthepistontwostrokesineachcycle.Yourtractorprobablyhasacompleteelectricsystemwhichprovideselecticutyfortheself-starter,forignitingthefuel,andforlights.Insomedesignselectricityisalsousedforcertainotheraccessorycircuits.Suchcompl

14、etesystemscompriseseveralcircuits(1)generatorcircuit,(2)startingmotorcircuit,(3)lighingcircuit,(4)ignitioncircuit.Thestoragebatterymaywellbeconsideredthebasisofthecompletesystembacauseitisconnectedtoandworkswithallfouroftheseprincipalcircuits.Wemustreducetherelativelyfastspeedoftheengineandtransmiti

15、tspowertothedrivingmenberstoobtainsuitablespeedsandpullingpowerforthedifferentfarmjops.Youmaywantafstforwardspeedforhaulingformthefieldoronthehighwaybutamuchslowerfortions.Aslo,youmsuthavesomemeansofreversingthedirectionofrotationofthedrivingmembers.Muchofthenecessryspeedreductionisaccomplishedbythe

16、sliding(speed-changing)gearsoftheassemblywhichisususllycalledthe"transmission."Furtherreductionissecuredatthedifferentialandbythefinaldrivepinionsandbullgears(Fig.9).Fig.9Youselectthespeedyouwantbyshiftingoneoftheslidinggears,whicharesplinedtobetransmissionshaft.Withthegearshiftlever,youca

17、nmovethenforwardorbackward;youcanmeshanycertainslidinggearwithit'smatinggearonthecounter-shaft.Intheschematicdiagram(Fig.9),gearsC,E,G,angKareslidinggears.GearA,attheendofthedriveshaft,andgearB,ontheciuntershaft,areinconstantmesh.Hence,thecountershaftandallit'srigidlyconnectedgearsareinmotio

18、nwheneverthedriveshaftrevolves.Whenyoudisengagetheclutch,allgearsareatrestandnopoweristransmittedtothedrivewheels.However,whenyoumoveoneoftheslidinggears,suchasC,intomeshwithD,thenbyengagingtheclutch,youcompletetheconnectionbnetweentheengineandthedrivewheels.ContactbetweengearsCandD(asshown)wouldgiv

19、elow,orfirst,speed;engaginggearsEandFwouldgivesceondspeed;gearGandHwouldgivethirdspeed.Whennoneoftheslidinggersisinmeshwithit'scountershaftgear,thegearsaresaidtobein“neutral.”Reversespeedisobtainedbytheuseofasmall/pinionRbetweenthecountershaftgearIandtheslidinggearK,whichcausesthetransmissiondri

20、veshafttibedrivenintheoppositedirection.Intoday'stractorstherearestillmoregearcombingationsgivingmoreforwardspeeds;theseareneededforthemanyoperationsnowperformedwithfarmtractors.Insometractormodels,anadditionalspeed-reducingandtoedue-increasingunitisinstalledbetweentheenginecluthandthetransmisio

21、ndrivinggear.Thisunitiscontrolledwithaseparatelevernearthetractorseat.Whentheunitincereasesthe“torque"orpullingforceobtainedfromthatspeed.Whenyouusethisunit,yougetaratioofaboutthreetotwobetweentheenginecrankshaftandthetransmissiondrivegear(whenyouarenotusingityouhavetheusualdirectratiobetweenth

22、esetwoparts).Becausethis“torqueamplifier"isaheadoftheregularspeed-changinggears,itreduceseachspeedyouobtainfromthevariousgearcombinations.Soitdoublesthenumberofavailablespeeds,Eachspeedisreducedaboutone-thirdandthetorque,orpullingforce,fromsuchslowerspeedisincreasedby45percent.Thisisveryhelpful

23、whenplowingthroughtoughspotsordiskdingthroughwetspots.Youcanengagethetorqueamplifier-reducespeedandincreasepull-withoutstopping.And,whenthroughtheheavypull,youcandisengageitandreturntonormalspeedwithoutstopping.农用拖拉机拖拉机的发展历史很长，在这里不再赘述。拖拉机发展史上的几个里程碑是：1890年内燃机在美国拖拉机上的首次使用；1901年Ivel拖拉机的问世；1917年美国福特拖拉机以

24、及1923年万国公司Farmall拖拉机的相距出现。30年代，低压充气轮胎的应用迅速普及，并且推广了第一批Forguson系统的拖拉机，这种拖拉机配有力调节的三点液压悬挂装置。拖拉机的分类。目前制造的拖拉机可分类如下：A.按照获得牵引力及自身推进的方法分：1.轮式拖拉机1 )三轮拖拉机。2 )四轮拖拉机。2.履带式拖拉机B.按照用途分：1 .通用型，即多用型拖拉机。2 .万能型，即中耕型拖拉机。轮式拖拉机：轮式拖拉机是主要的拖拉机类型，特别是在农用方面。现在制造的轮式拖拉机有三轮的或四轮的。通常的配置是在两个后驱动轮及一个或两个前导向轮。履带式拖拉机：履带式拖拉机的牵引机构实质上由两条成为履带

25、的重型封闭金属链条装置构成。每以条履带在两个铁轮上运转，其中一个铁轮具有链齿，用作驱动轮，另一个用作惰轮。转向是通过履带本身来完成的，即通过减慢其中一条履带的运动速度使之低于另一条的速度的办法来完成的。通用型即多用型拖拉机：通用型拖拉机基本上是一种传统设计的拖拉机，例如普通的四轮拖拉机或履带式拖拉机。这种类型也被成为多用型拖拉机，它仅用来完成一般的拖拉机作业，包括田间作业和皮带作业，例如耕地、耙地、平路、联合收获、饲料粉碎等等。万能型拖拉机：万能型拖拉机即中耕型拖拉机，用来完成一般的农场的几乎所有的田间作业和皮带作业，包括中耕作物的播种和中耕在内。传统的拖拉机通常有两个用发动机驱动的后轮和两个

26、支重的前轮。用来为拖拉机提供动力的发动机类型是内燃机。发动机是拖拉机的心脏。正是在这里燃料的化学年能被转化为使轮子转动的机械能。内燃机和外燃机的区别仅仅是在：在内燃机力，势能转化为机械能完全与空气精确的混合，然后在控制的条件下燃烧。这种混合燃烧时就会膨胀，压力增大，推动活塞沿着气缸直线地向下运动。我们就说活塞作直线运动。该直线运动通过与活塞连接的连杆和曲柄机构转变为旋转运动。为了能有效地利用这种能量，对燃烧过程和膨胀压力必须加以控制。为此发动机必须具有：1 .一端密闭的管子即气缸，在这里燃油和空气的混合气被压缩和燃烧2 .活塞，它可以在气缸里只有滑动，但又与气缸配合严密，这样，膨胀的气体就能推

27、动活塞沿着气缸向下运动而不从周围漏掉。3 .气缸的两个同期道：一个是燃料和空气的混合气进入气缸的进气口，另一个是排泄废气的排气口。4 .两个阀门：控制混合气进入气缸的进气门和控制废气排放的排气门。根据阀门的开笔和活塞的位置，使混合气正时点火，就可以使活塞连续地在气缸里上下运动。内燃机一旦运动，具工作过程就是指每个气缸里所发生的一系列的动作。一般有两种不同的循环：四行程循环和二行程循环。在四冲程循环中，曲柄转两圈，活塞完成四个行程，一个行程就是指活塞自气缸的一端运动到另一端。在二行程循环中，每一个循环曲柄转一圈，活塞完成两个行程。拖拉机大概都有一套完整的电系来为电动机、燃料点火和照明设备供电。在有些拖拉机的设计上还要为其它一些辅助线路供电。一套完整的电系包括下面几条线路：（1）发电线路；（2）电起动机线路；（3）照明线路；（4）点火线路。因为蓄电池与所有这四条主要线路连接并为其供电，所以完全可以把它看作是整个电系的基础。为了获得适合各种农业工作的速度和牵