外文翻译--组合式机械变速器的现状和发展.doc

附录1组合式机械变速器的现状和发展重型汽车装载质量大，使用条件复杂，欲保证其具有良好的动力性、经济型和加速性，则必须扩大传动比范围并增加挡数。传统结构三轴式变速器档位数一般最多为5个前进挡和1个倒档，最大输出转矩为8400Nm。近几年重型汽车发动机功率200350kw，输出转矩9002200Nm，需要爬行档速比1017，要求档位间隔小，速比阶小于30%，这就需要更多档位（816个前进挡）。先让传统结构的三轴式变速器远不能满足上述要求，分段式配档（倍档）和插入式配档（半档）的组合式变速器应运而生。倍档组合式变速器是在主变速器后部串联安装一个2档（高档和低档）副变速器，是主变速器的档位数增加1倍，所增加的档位传动比数值等于主变速器传动比和副变速器传动比的乘积，而且齿轮对数少于档位数，因此箱体尺寸缩短，轴的长度减短，刚度增大，所以增大了变速器的容量。例如在一个5档组变速器后端，串联安装一个具有高、低2档的副吧变速器，即可组成10档（或9档）倍档组合式机械变速器。增加倍档组合式变速器最大输入扭矩和最低档传动比的技术难点是副变速器齿轮强度容量不足，超出齿轮轮齿的承载能力。解决的办法将有一个齿轮承受的载荷分流给几个齿轮来承受。这样，输入齿轮扭矩不变，每个齿轮的负荷将等于同时接触齿轮的平均数值。倍档组合式变速器的副变速器功率分流方法有两种：一种是采用形象齿轮系的传动方法。这种结构非常紧凑，体积小而扭矩容量大，直到现在仍广泛应用；另一种方法是采用双中间轴传动结构。双中间轴传动最大工艺难点是保证主传动齿轮能和所啮合的双中间轴齿轮的轮齿同时接触问题，解决的办法是用浮动主传动齿轮的方法来消除齿轴对位的制造误差，确保齿轮同时接触，达到功率分流的目的。与此相适应的换挡同步器也要有一定的浮动量。半档组合式变速器是将副变速器传动比均匀的插入传动比间隔大的主变速器各档传动比之间，式变速器的档位数增加1倍。半档副变速器串联在主变速器前部，它只有一对齿轮副和同步器。早起的半档副变速器由单独的一个箱子组成，近年来发展成将半档齿轮副直接放到变速器之内，既缩短变速器长度由简化半档结构。半档副变速器由一对类似一轴常啮合齿轮副组成，齿圈套在动力输入轴上自由转动，当动力输入轴上的齿圈与住变速器一轴结合时，各档传动比均由主变速器一轴齿轮副组成。当齿圈与动力输入轴上的结合齿轮的齿圈连接时，常啮合齿轮与主变速器上的中间轴连接，因此主变速器中间轴也旋转，由此组成的各档传动比均匀地插入主变速器各档位传动比之间。因为半档组合式变速器的长度小于倍档组合式变速器，而且他的结构简单、成本低、维修保养容易深受用户青睐。国外货车采用组合式变速器的情况是：发动机的功率在200kw以下的汽车基本上采用半档组合式变速器；发动机功率在200kw以上的多采用倍档（或倍档加半档）组合式变速器。附录2CombinedmechanicaltransmissionofthepresentandthefutureHeavydutytruckmountqualityconditionsfortheuseoflarge,complex,andtoensureitsexcellentdynamicperformance,economicalandAcceleration,youmustexpandthescopeofthetransmissionratioandincreasethenumberofguards.Traditionalstructureofthree-shaftgearboxstallnumberusuallyuptofiveforwardvisorand1reversegear,maximumoutputtorquefor8400Nm.Inrecentyears,heavydutytruckenginepower200350kw,outputtorque9002200Nm,crawlingstallsratio1017,stalls,speedratio-orderintervalislessthan30%,andthisrequiresmorestalls(816forwardgear).Letthetraditionalstructureofthree-shaftgearboxisfarfromabletosatisfytheaboverequirements,thesegmentaldistributionoutlets(doublestalls)andinsert-withfile(file)ofacombinedtransmissioncameintobeing.Timesthestalliscombinedinthemaintransmissiongearboxback-lineinstalleda2stalls(high-gradeandlow-grade)Deputytransmission,istheprimarytransmissiongearnumberdoubled,theincreaseinstallspeedratiovalueequaltothemaintransmissiongearratioandtheproductofDeputytransmissiongearratioandthenumberofgear,thelogarithmislessthanthestallsoboxsizereducedthelengthoftheshaft,stiffnessincreasereduced,increasingthetransmissioncapacity.Forexample,ina5stallsgrouptransmissionbackend,in-lineinstallationofahighandlowsidebar2stalls,composedof10transmissionstostall(or9stalls)timesthestallcombinedmechanicaltransmission.IncreasetimesstalltranmisssionmaxinputtorqueandlowtransmissionratiooftechnicaldifficultyisDeputytransmissiongearstrengthcapacityisinsufficient,excessgearcarryingcapacity.Thesolutionwillhaveagearbearloadshunttoseveralgeartobear.Inthisway,theinputgeartorqueconstant,eachgearloadwillbeequaltotheaveragecontactgearatthesametime.Timesthestallsofthecombinedtransmissiontransmissionpowersplittwoways:oneistheimageofthedrivegeartrains.Thisstructureisverycompact,smallandbigtorquecapacityuntilnowisstillwidelyused；thealternativeistousetwointermediateshafttransmissionstructure.DoubleMiddleshaftdrivemaximumprocessdifficultiesisthatmaindrivegearandthemeshofthetwin-shaftgearteethatthesametime,contacts,thesolutionistousefloatingmethodmaindrivegeartoeliminatetoothshaftalignmentofmanufacturingerrors,ensurethatthegearatthesametime,meetthepowersplitends.AdapttoshiftingtheSynchronizershouldalsohaveacertainamountoffloating.HalfstallsiscombinedtransmissiontransmissiongearratioevenViceinsertratiospacingoftheprimarytransmissionbetweenvariousstallstransmissionratio,thenumberoftransmissionsofstallsdoubled.Half-stallsontheprimaryDeputytransmission-linetransmissionfront,itisonlyapairofgearsandSynchronizer.Earlyhalfgearpairtransmissionfromasinglebox,inrecentyearsdevelopedintohalf-gearpairdirectlyonthetransmission,whichshortenthetransmissionlengthfromahalfstallsstructure.simplificationHalfstallsVicetransmissiongearboxbyasimilaroneaxisconstantgearpair,toothsnaresindynamicinputshaftrotatefreely,whenpowerinputshaftgearandlivetransmissionwithanaxis,thestallspeedratioofthemaintransmissionashaftgears.Whentheringgearandpowerinputshaftonthecombinationofgeartoothringconnection,gearandmaintransmissiononintermediateshaftconnection,thereforethemaintransmissiongearboxshaftisrotated,constitutingthestallspeedratioevenlyintothemaintransmissionbetweenthestallspeedratio.Becausehalfthelengthofacombinedtransmissionspeedislessthandoublestallscombinedgearbox,andhissimp