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汽车设计课程设计说明书课题：乘用车主减速器设计姓名：鱿鱼学号：222222222专业：车辆工程（汽车设计与制造）班级：本汽设091指导教师：二〇一二年七月摘要汽车正常行驶时，发动机的转速通常在2000至3000r/min左右，如果将这么高的转速只靠变速箱来降低下来，那么变速箱内齿轮副的传动比则需很大，而齿轮副的传动比越大，两齿轮的半径比也越大，换句话说，也就是变速箱的尺寸会越大。另外，转速下降，而扭矩必然增加，也就加大了变速箱与变速箱后一级传动机构的传动负荷。所以，在动力向左右驱动轮分流的差速器之前设置一个主减速器。主减速器的存在有两个作用，第一是改变动力传输的方向，第二是作为变速器的延伸为各个档位提供一个共同的传动比。变速器的输出是一个绕纵轴转动的力矩，而车轮必须绕车辆的横轴转动，这就需要有一个装置来改变动力的传输方向。之所以叫主减速器，就是因为不管变速器在什么档位上，这个装置的传动比都是总传动比的一个因子。有了这个传动比，可以有效的降低对变速器的减速能力的要求，这样设计的好处是可以有效减小变速器的尺寸，使车辆的总布置更加合理汽车主减速器最主要的作用，就是减速增扭。我们知道发动机的输出功率是一定的，根据功率的计算公式W=M*v（功率=扭矩*速度），当通过主减速器将传动速度降下来以后，能获得比较高的输出扭矩，从而得到较大的驱动力。此外，汽车主减速器还有改变动力输出方向、实现左右车轮差速或中后桥的差速功能。关键字：传动系；驱动轴；主减速器AbstractNormaldrivingofthecar,theenginespeedisusuallyaround2000to3000r/min,ifsuchahighspeedalonegearboxtoreducedown,thenthegearboxGearsgearthanyouneed,andthedrivegearpairratioincreases,theradiusofthetwogearsisgreater,inotherwords,isthegearboxsizelarger.Inaddition,thespeeddecreases,torqueboundtoincrease,willincreasethetransmissionloadofagearboxandgearboxtransmission.Therefore,priortothediversionofpowertotheleftandrightdrivingwheeldifferentialtosetupamaingearbox.Theexistenceofthemaingearboxhastworoles,thefirstistochangethedirectionofpowertransmission,andthesecondisasanextensionofthetransmissiontoprovideacommontransmissionratioforeachgear.Atransmissionoutputisaroundthelongitudinalaxisofrotationofthetorque,thewheelshavetogoaroundthehorizontalaxisrotationofthevehicle,whichrequiresadevicetochangethedirectionofthetransmissionofpower.Iscalledamaingearbox,becauseregardlessoftransmission,thegeartransmissionratioofthisdevicearethetotaltransmissionratioofafactor.Withthistransmissionratio,caneffectivelyreducetheabilitytoslowdowntransmission,thebenefitsofthisdesigncaneffectivelyreducethesizeofthetransmission,sothatthegeneralarrangementofthevehicleamorereasonableAutomaingearboxofthemostimportantroleistoslowtheincreaseintwist.Weknowthattheengineoutputpoweriscertain,togetarelativelyhighoutputtorque,largerdrivingforce.Inaddition,theautomotivemaingearboxtochangethedirectionofpoweroutput,leftandrightwheeldifferentialorrearaxledifferentialfeatures.Keywords:transmissionsystem;driveshaft;mainreducer目录1课程设计目的.....................................................12单级主减速器结构方案分析...................................................................................22.1主减速器的的结构形式....................................................................................22.1.1主减速器齿轮的类型.................................................................................22.1.2主减速器主动锥齿轮的支承型式及安置方法.........................................32.1.3主减速器从动锥齿轮的支承型式及安置方法.........................................42.1.4主减速器的轴承预紧及齿轮啮合调整.....................................................42.1.5主减速器的减速型式.................................................................................52.2主减速器的基本参数选择与设计计算............................................................72.2.1主减速比0i的确定....................................................................................72.2.2主减速齿轮计算载荷的确定.....................................................................82.3主减速器齿轮基本参数的选择......................................................................102.3.1齿数的选择...............................................................................................102.3.2节圆直径的选择.......................................................................................112.3.3齿轮端面模数的选择...............................................................................112.3.4齿面宽的选择...........................................................................................122.3.5双曲面齿轮的偏移距E...........................................................................122.3.6螺旋锥齿轮螺旋方向...............................................................................132.3.7螺旋角的选择...........................................................................................132.3.8齿轮法向压力角的选择...........................................................................162.4螺旋锥齿轮几何尺寸计算.............................................................................172.5主减速器螺旋锥齿轮强度计算......................................................................202.5.1计算圆周力.................................................................................................202.5.2轮齿弯曲强度：.........................................................................................212.5.3轮齿接触强度：.........................................................................................242.6锥齿轮的材料及热处理：................................................................................263主减速器轴承的计算...............................................................................................283.1作用在主减速器主动齿轮上的力....................................................................283.2主减速器轴承载荷的计算..................................................................................323.3主减速器轴承的当量载荷及寿命......................................................................334主减速器齿轮的材料及热处理.................................................................................36