变速器的毕业设计

中文摘要商用车作为汽车家族的主要成员，在现代交通运输中发挥着不可替代的作用。近年来，以其前所未有的发展势头，成为客运、货运用车的主力军。轻型客车作为一种常用商用车型，为我们的日常生活带来了许多方便。变速器是汽车传动系统中一个比较关键的部件，它设计的好坏直接影响到汽车的实际使用性能。本文主要说明了轻型客车变速器的设计计算过程,主要分为两大部分——设计部分和工艺部分。设计部分叙述了轻型汽车手动机械变速器的功用、要求，比对了变速器各种结构方案，说明了变速器主要参数的确定方法、齿轮的几何计算和校核过程、轴的尺寸确定和校核过程、轴承等标准零件的选用方法和同步器的选用方法。同时分析设计了与之相适应的操纵机构，最后给变速器壳体的设计方案图纸。计算过程采用MATLAB编程来进行，主要包括齿轮强度校核程序，轴的强度校核程序和轴的刚度校核程序。主要电算程序和计算结果将另附一册进行详细说明。机械加工工艺是实现产品设计，组织生产，加工操作，保证产品质量的重要依据技术保证。本文的工艺部分主要对典型零件的工艺过程进行了分析，包括轴类零件、齿轮类零件、壳体类零件、叉类零件及其他类零件，并选取有代表性的零件，确定了各类零件的材料，制定了工艺过程卡片。另外，对装配过程也给出了详细的说明。关键词手动变速器齿轮轴同步器壳体工艺MATLABTitleThetransmissiondesignforthelight-dutycoachAbstractAsamainkindofmodernautomotivevehicle,thecommercialvehicleisplayinganimportantroleintransportationwhichcannotbeplacedbyothersnowadays.Inresentyears,thecommercialvehicleiswidelyusedforfreightandpassengertransportation.Asacommontypeofcommercialcar,thelight-dutycoachmakesourlivingmoreconvenient.Thetransmissionisakeycomponentinthedrivelineofanautomotivevehicle.Thispaper,whichmainlyconsistsoftwoparts—thepartdesignandthemachining,introduceshowthemanualtransmissionforlight-dutycoachisdesignedandproduced.Thefirstpartintroducesthefunctionofthetransmissionandthedemand.Bycomparingsomekindsofalinements,thepapermadeanoptimization.Thepaperalsointroduceshowtochoosethemainparametersoftransmission,thegears,theshafts,thesynchronizersetc.ThepapergivessomeMATLABprogramstocheckthegearsandshaftsinordertoensurethattransmissionissafeenoughwhenitisworking.Themainprogramofthecalculationandtheresultwillbeexplainedindetailsinanotherappendix.Whatismore,abriefintroductiontothedesignofshiftmechanicsandthedrawingsisgiven.Thesecondpartintroducestheprocessingofmachining.Machiningisanimportantguaranteeandproofforsucceedofproductdesign,manufacturing,processingoperationandhighquality.Thispartmainlyanalyzesthemachiningprocessingoftypicalcomponents,suchasshafts,gears,shells,picksandsoon.Italsotakessomeofthetypicalcomponentsasexamplestoshowhowtomakeachoiceofthematerialsforvariesofcomponentsandmakestheflowchartfortheprocessing.Finally,theassemblyprocesswillbeexplainedindetails.KeywordsManualtransmissionGearShaftSynchronizerHousingMachiningMATLAB目录1绪论................................................................11.1毕业设计任务及要求.............................................11.2变速器的功用和设计要求..............................................................................................12变速器结构方案的选择................................................32.1两轴式变速器和中间轴式变速器................................................................................32.2齿轮的安排.........................................................................................................................42.3换挡结构形式....................................................................................................................62.4倒挡的结构方案及倒挡的位置.....................................................................................83变速器主要参数的选择...............................................103.1变速器挡数及各挡传动比.............................................................................................103.2中心距A..............................................................................................................................103.3外形尺寸.............................................................................................................................114变速器齿轮参数的确定...............................................124.1模数......................................................................................................................................124.2压力角.................................................................................................................................124.3螺旋角.................................................................................................................................124.4齿宽......................................................................................................................................134.5各挡齿轮齿数的分配......................................................................................................135同步器的设计计算...................................................186变速器结构元件.....................................................216.1齿轮......................................................................................................................................216.2轴及相关零件...................................................................................................................216.3变速器壳体....................................................237零件的校核.........................................................247.1齿轮的校核....................................................247.2轴的校核......................................................268变速器操纵机构.....................................................309工艺分析...........................................................319.1壳体加工工艺...................................................................................................................319.2拨叉加工工艺..........................