兩軸式變速器設(shè)計說明書

.PAGE8.第1章變速器主要參數(shù)的選擇與計算設(shè)計初始數(shù)據(jù)最高車速：=200Km/h發(fā)動機最大功率：=120KW最大轉(zhuǎn)矩：=238整備質(zhì)量：=1700Kg最大轉(zhuǎn)矩轉(zhuǎn)速：=3500r/min車輪：215/55R17變速器各擋傳動比的確定①滿足最大爬坡度〔1.1式中：G—作用在汽車上的重力,,—汽車質(zhì)量,—重力加速度,=20090N；—發(fā)動機最大轉(zhuǎn)矩,=238N.m；—傳動系效率,=90%；—車輪半徑,=0.3334m；—滾動阻力系數(shù),取=0.015；—爬坡度,取=20°帶入數(shù)值計算得②滿足附著條件：·φ〔1.2Φ為附著系數(shù),取值范圍為0.5~0.6,取為0.6為汽車滿載靜止于水平面,驅(qū)動橋給地面的載荷,這里取70%mg；計算得≤18.35；②由①②得11.59≤≤18.35；取=3.0；在計算范圍內(nèi)。=7.96km/h<10km/h,檢驗最低穩(wěn)定車速合格,故傳動比合適。其他各擋傳動比的確定：按等比級數(shù)原則,一般汽車各擋傳動比大致符合如下關(guān)系：〔1.3式中：—常數(shù),也就是各擋之間的公比；五檔設(shè)置為直接當故,因此,各擋的傳動比為：==1.32〔1.4所以其他各擋傳動比為：=3.0,==2.27,==1.72,=1.30,=1變速器傳動方案的確定圖2-1a為常見的倒擋布置方案。圖2-1b所示方案的優(yōu)點是換倒擋時利用了中間軸上的一擋齒輪,因而縮短了中間軸的長度。但換擋時有兩對齒輪同時進入嚙合,使換擋困難。圖2-1c所示方案能獲得較大的倒擋傳動比,缺點是換擋程序不合理。圖2-1d所示方案針對前者的缺點做了修改,因而取代了圖2-1c所示方案。圖2-1e所示方案是將中間軸上的一,倒擋齒輪做成一體,將其齒寬加長。圖2-1f所示方案適用于全部齒輪副均為常嚙合齒輪,換擋更為輕便。為了充分利用空間,縮短變速器軸向長度,有的貨車倒擋傳動采用圖2-61所示方案。其缺點是一,倒擋須各用一根變速器撥叉軸,致使變速器上蓋中的操縱機構(gòu)復雜一些。本設(shè)計采用圖2-1f所示的傳動方案。圖1-1變速器倒檔傳動方案因為變速器在一擋和倒擋工作時有較大的力,所以無論是兩軸式變速器還是中間軸式變速器的低檔與倒擋,都應(yīng)當布置在在靠近軸的支承處,以減少軸的變形,保證齒輪重合度下降不多,然后按照從低檔到高擋順序布置各擋齒輪,這樣做既能使軸有足夠大的剛性,又能保證容易裝配。倒擋的傳動比雖然與一擋的傳動比接近,但因為使用倒擋的時間非常短,從這點出發(fā)有些方案將一擋布置在靠近軸的支承處。圖1.2變速器傳動示意圖中心距A的確定初選中心距：發(fā)動機前置前驅(qū)的乘用車變速器中心距A,可根據(jù)發(fā)動機排量與變速器中心距A的統(tǒng)計數(shù)據(jù)初選,A=76mm齒輪參數(shù)模數(shù)對貨車,減小質(zhì)量比減小噪聲更重要,故齒輪應(yīng)該選用大些的模數(shù)；從工藝方面考慮,各擋齒輪應(yīng)該選用一種模數(shù)。嚙合套和同步器的接合齒多數(shù)采用漸開線。由于工藝上的原因,同一變速器中的接合齒模數(shù)相同。其取值范圍是：乘用車和總質(zhì)量在1.8～14.0t的貨車為2.0～3.5mm；總質(zhì)量大于14.0t的貨車為3.5～5.0mm。選取較小的模數(shù)值可使齒數(shù)增多,有利于換擋。表1.1汽車變速器齒輪法向模數(shù)車型乘用車的發(fā)動機排量V/L貨車的最大總質(zhì)量/t1.0≤V≤1.61.6＜V≤2.56.0＜≤14＞14.0模數(shù)/mm2.25～2.752.75～3.003.50～4.504.50~6.00表1.2汽車變速器常用齒輪模數(shù)一系列1.001.251.502.002.503.004.005.006.00二系列1.752.252.753.253.503.754.505.50——發(fā)動機排量為2.5L,根據(jù)表2.2.1及2.2.2,齒輪的模數(shù)定為2.75~3.00mm。壓力角和螺旋角理論上對于乘用車,為加大重合度降低噪聲應(yīng)取用14.5°、15°、16°、16.5°等小些的壓力角；對商用車,為提高齒輪承載能力應(yīng)選用22.5°或25°等大些的壓力角。國家規(guī)定的標準壓力角為20°,所以變速器齒輪普遍采用的壓力角為20°。實驗證明：隨著螺旋角的增大,齒的強度也相應(yīng)提高。在齒輪選用大些的螺旋角時,使齒輪嚙合的重合度增加,因而工作平穩(wěn)、噪聲降低。斜齒輪傳遞轉(zhuǎn)矩時,要產(chǎn)生軸向力并作用到軸承上。乘用車兩軸式變速器螺旋角：20°～25°齒寬直齒,為齒寬系數(shù),取為4.5～8.0,取7.0；斜齒,取為6.0～8.5。采用嚙合套或同步器換擋時,其接合齒的工作寬度初選時可取為2～4mm,取4mm。一檔和倒檔齒寬b=3×7=21mm二檔到五檔齒寬b=2.5×7=17.5mm齒頂高系數(shù)在齒輪加工精度提高以后,包括我國在內(nèi),規(guī)定齒頂高系數(shù)取為1.00.齒輪的設(shè)計計算與校核齒輪的設(shè)計與計算各擋齒輪齒數(shù)的分配一擋齒輪為斜齒輪,模數(shù)為3.0,初選=20°一擋傳動比為〔2.1為了求,的齒數(shù),先求其齒數(shù)和,斜齒〔2.2==47.61取整為48取=13=48-13=35對中心距進行修正因為計算齒數(shù)和后,經(jīng)過取整數(shù)使中心距有了變化,所以應(yīng)根據(jù)取定的和齒輪變位系數(shù)重新計算中心距,再以修正后的中心距作為各擋齒輪齒數(shù)分配的依據(jù)。==76.59mm〔2.3對一擋齒輪進行角度變位：端面嚙合角：tan=tan/cos=0.392〔2.4=21.42°嚙合角：cos==0.93〔2.5=21.29°變位系數(shù)之和〔2.6=0.03查變位系數(shù)線圖得：計算一擋齒輪9、10參數(shù)：分度圓直徑=3.0×13/cos20°=45.22mm=3.0×35/cos20°=106.59mm齒頂高=3.95mm=3.23mm式中：=〔76-76.59/3.0=-0.197=0.0254+0.197=0.2224齒根高=3.39mm=4.11mm齒頂圓直徑=52.22mm=111.99mm齒根圓直徑=38.44mm=98.37mm當量齒數(shù)=15.66=42.17二擋齒輪為斜齒輪,模數(shù)為2.5,初選=21°==56.76取整為57=18=39則,==2.17≈=2.27對二擋齒輪進行角度變位：理論中心距=76.28mm端面壓力角tan=tan/cos=21.31°端面嚙合角=變位系數(shù)之和=0查變位系數(shù)線圖得：0=0.09=二擋齒輪參數(shù)：分度圓直徑=48.06mm=104.13mm齒頂高=3.7mm=3.3mm式中：=0.11=-0.11齒根高 =2.8mm=3.4mm齒頂圓直徑=55.46mm=110.73mm齒根圓直徑=42.46mm=97.33mm當量齒數(shù)=22.14=47.97三擋齒輪為斜齒輪,初選=22°模數(shù)為2.5=1.72=56.37,取整為57得=20.96取整為21,=36==1.71≈=1.72對三擋齒輪進行角度變?yōu)椋豪碚撝行木?76.86mm端面壓力角tan=tan/cos=0.389=21.25°端面嚙合角==0.941變位系數(shù)之和=-0.31查變位系數(shù)線圖得：=0.19=-0.50三擋齒輪5、6參數(shù)：分度圓直徑=65.56mm=86.42mm齒頂高=2.87mm=2.64mm式中：=-0.344=0.034齒根高=3.48mm=4.02mm齒頂圓直徑=71.3mm=91.7mm齒根圓直徑=58.92mm=79.32mm當量齒數(shù)=26.35=45.17四擋齒輪為斜齒輪,初選=23°模數(shù)=2.5=取整為56=23.34,取整為24=32則：==1.33≈=1.30對四擋齒輪進行角度變位：理論中心距=76.09mm端面壓力角tan=tan/cos=0.396=21.60°端面嚙合角==0.930變位系數(shù)之和=-0.05查變位系數(shù)線圖得：=-0.02=-0.03四擋齒輪3、4參數(shù)：分度圓直徑=74.5mm=77.48mm齒頂高=2.82mm=2.71mm式中：=-0.04=0.01齒根高=3.38mm=3.49mm齒頂圓直徑=80.14mm=82.9mm齒根圓直徑=67.74mm=70.5mm當量齒數(shù)=30.77=41.03五擋齒輪為斜齒輪,初選=24°模數(shù)=2.5=1.0取整為56=28,取29=27則：==0.93≈=1.0對五擋齒輪進行角度變位：理論中心距=76.63mm端面壓力角tan=tan/cos=0.398=21.70°端面嚙合角==0.936變位系數(shù)之和=-0.05查變位系數(shù)線圖得：=-0.02=-0.03五擋齒輪1、2參數(shù)：分度圓直徑=86.42mm=65.56mm齒頂高=2.82mm=2.71mm式中：=-1.50=1.45齒根高=3.38mm=3.49mm齒頂圓直徑=92.06mm=70.96mm齒根圓直徑=79.66mm=58.8mm當量齒數(shù)=38.04=35.41確定倒擋齒輪齒數(shù)倒擋齒輪選用的模數(shù)與一擋相同,倒擋齒輪的齒數(shù)一般在21～23之間,初選后,可計算出中間軸與倒擋軸的中心距。=23,=14,則：==55.5mm取56mm為保證倒擋齒輪的嚙合和不產(chǎn)生運動干涉,齒輪12和11的齒頂圓之間應(yīng)保持有0.5mm以上的間隙,則齒輪11的齒頂圓直徑應(yīng)為=2×76－48－1=103mm取102mm=32為了保證齒輪11和12的齒頂圓之間應(yīng)保持有0.5mm以上的間隙,取=27計算倒擋軸和第二軸的中心距=82.5mm計算倒擋傳動比=1.64分度圓直徑=42mm=69mm=96mm齒頂高齒根高mm尺頂圓直徑d+248mmmmmm尺根圓直徑2mmmmmm變位系數(shù)的齒輪確立齒輪、當量齒數(shù)比根據(jù)當量齒數(shù)比,查《機械設(shè)計手冊》小齒輪變位系數(shù)為,則大齒輪變?yōu)橄禂?shù)為齒輪、當量齒數(shù)比=1.39根據(jù)當量齒數(shù)比,查《機械設(shè)計手冊》小齒輪變位系數(shù)為,則大齒輪變?yōu)橄禂?shù)為齒輪材料的選擇原則1、滿足工作條件的要求不同的工作條件,對齒輪傳動有不同的要求,故對齒輪材料亦有不同的要求。但是對于一般動力傳輸齒輪,要求其材料具有足夠的強度和耐磨性,而且齒面硬,齒芯軟。2、合理選擇材料配對如對硬度≤350HBS的軟齒面齒輪,為使兩輪壽命接近,小齒輪材料硬度應(yīng)略高于大齒輪,且使兩輪硬度差在30～50HBS左右。為提高抗膠合性能,大、小輪應(yīng)采用不同鋼號材料。3、考慮加工工藝及熱處理工藝變速器齒輪滲碳層深度推薦采用下列值：滲碳層深度0.8～1.2時滲碳層深度0.9～1.3時滲碳層深度1.0～1.3表面硬度HRC58～63；心部硬度HRC33～48對于氰化齒輪,氰化層深度不應(yīng)小于0.2；表面硬度HRC。對于大模數(shù)的重型汽車變速器齒輪,可采用25CrMnMO,20CrNiMO,12Cr3A等鋼材,這些低碳合金鋼都需隨后的滲碳、淬火處理,以提高表面硬度,細化材料晶面粒。計算各軸的轉(zhuǎn)矩發(fā)動機最大扭矩為192N.m,齒輪傳動效率99%,離合器傳動效率98%,軸承傳動效率96%。輸入軸==238N.m輸出軸==150×96%×99%=226.19N.m輸出軸一擋=226.19×2.69×0.96×0.99=578.27N.m輸出軸二擋=226.19×2.17×0.96×0.99=466.48N.m輸出軸三擋=226.19×1.71×0.96×0.99=367.60N.m輸出軸四擋=226.19×1.33×0.96×0.99=285.91N.m輸出軸五擋=226.19×0.93×0.96×0.99=199.93N.m倒擋=226.19××2.85=612.67N.m輪齒的校核輪齒彎曲強度計算1、倒檔直齒輪彎曲應(yīng)力圖2.1齒形系數(shù)圖〔2.7式中：—彎曲應(yīng)力〔MPa；—計算載荷〔N.mm；—應(yīng)力集中系數(shù),可近似取=1.65；—摩擦力影響系數(shù),主、從動齒輪在嚙合點上的摩擦力方向不同,對彎曲應(yīng)力的影響也不同；主動齒輪=1.1,從動齒輪=0.9；—齒寬〔mm；—模數(shù)；—齒形系數(shù),如圖3.1。當計算載荷取作用到變速器第一軸上的最大轉(zhuǎn)矩時,一、倒擋直齒輪許用彎曲應(yīng)力在400～850MPa,貨車可取下限,承受雙向交變載荷作用的倒擋齒輪的許用應(yīng)力應(yīng)取下限。計算倒擋齒輪11,12,13的彎曲應(yīng)力,,=21,=13,=37,=0.125,=0.142,=0.138,=612.67N.m,=226.19N.m=719.114MPa<400～850MPa==735.948MPa<400～850MPa==512.219MPa<400～850MPa斜齒輪彎曲應(yīng)力〔2.8式中：—計算載荷,N·mm；—法向模數(shù),mm；—齒數(shù)；—斜齒輪螺旋角,°；—應(yīng)力集中系數(shù),=1.50；—齒形系數(shù),可按當量齒數(shù)在圖中查得；—齒寬系數(shù)—重合度影響系數(shù),=2.0。當計算載荷取作用到變速器第一軸上的最大轉(zhuǎn)矩時,對乘用車常嚙合齒輪和高擋齒輪,許用應(yīng)力在180～350MPa范圍,對貨車為100～250MPa?！?計算一擋齒輪9,10的彎曲應(yīng)力,=13,=35,=0.16,=0.12,=578.27N.m,=226.19N.m,==344.38MPa<180～350MPa==245.26MPa<180～350MPa〔2計算二擋齒輪7,8的彎曲應(yīng)力=18,=39,=0.16,=0.12,=466.48N.m,=226.19N.m,==318.79MPa<180～350MPa==345.72MPa<180～350MPa〔3計算三擋齒輪5,6的彎曲應(yīng)力=21,=36,=0.15,=0.12,=367.60N.m,=226.19N.m==290.79MPa<180～350MPa==317.25MPa<180～350MPa〔4計算四擋齒輪3,4的彎曲應(yīng)力=24,=32,=0.14,=0.12,=285.91N.m,=226.19N.m==270.65MPa<180～350MPa==261.95MPa<180～350MPa〔5計算五擋齒輪1,2的彎曲應(yīng)力=29,=27,=0.16,=0.15,=226.19N.m,=199.93.m==194.50MPa<180～350MPa==176.81MPa<180～350MPa輪齒接觸應(yīng)力σj〔2.9式中：—輪齒的接觸應(yīng)力,MPa；—計算載荷,N.mm；—節(jié)圓直徑,mm；—節(jié)點處壓力角,°,—齒輪螺旋角,°；—齒輪材料的彈性模量,MPa；—齒輪接觸的實際寬度,mm；、—主、從動齒輪節(jié)點處的曲率半徑,mm,直齒輪、,斜齒輪、；、—主、從動齒輪節(jié)圓半徑<mm>。將作用在變速器第一軸上的載荷作為計算載荷時,變速器齒輪的許用接觸應(yīng)力見表3.2。彈性模量=210000N·mm-2,齒寬表2.2變速器齒輪的許用接觸應(yīng)力齒輪滲碳齒輪液體碳氮共滲齒輪一擋和倒擋1900～2000950～1000常嚙合齒輪和高擋1300～1400650～700〔1計算一擋齒輪9,10的接觸應(yīng)力=578.27N.m,=226.19N.m,,,=41.42mm,=u=111.41mm=8.02mm=21.58mm==1453.01<1900～2000MPa==1285.46MPa<1900～2000MPa〔2計算二擋齒輪7,8的接觸應(yīng)力=466.48N.m,=226.19N.m,,,=47.95mm,=104.05mm=9.41mm=20.42mm==1274.57MPa<1300～1400MPa==1369.03MPa<1300～1400MPa〔3計算三擋齒輪5,6的接觸應(yīng)力=367.60N.m,=226.19N.m,,,=56.09mm,=95.91mm=19.08mm=11.16mm==1017.11MPa<1300～1400MPa==949.94MPa<1300～1400MPa〔4計算四擋齒輪3,4的接觸應(yīng)力=285.91N.m,=226.19N.m,,,=65.24mm,=86.76mm=17.51mm=13.17mm==1057.22MPa<1300～1400MPa==988.06MPa<1300～1400MPa〔5五擋齒輪1,2的接觸應(yīng)力=226.19N.m,=199.93N.m,,,=78.76mm,=73.24mm=16.14mm=15.01mm=951.23MPa<1300～1400MPa==890.41MPa<1300～1400MPa〔6計算倒擋齒輪11,12,13的接觸應(yīng)力=612.67N.m,=226.19N.m,,,mmmmmm=6.67mm=20.01mm=10.77mm==1952.72MPa<1900～2000MPa==1508.00MPa<1900～2000MPa==352.91MPa<1900～2000MPa本章小結(jié)本章首先根據(jù)所學汽車理論的知識計算出主減速器的傳動比,然后計算出變速器的各擋傳動比；接著確定齒輪的參數(shù),如齒輪的模數(shù)、壓力角、螺旋角、齒寬、齒頂高系數(shù)；介紹了齒輪變位系數(shù)的選擇原則,并根據(jù)各擋傳動比計算各擋齒輪的齒數(shù),根據(jù)齒數(shù)重新計算各擋傳動比,同時對各擋齒輪進行變位。然后簡要介紹了齒輪材料的選擇原則,即滿足工作條件的要求、合理選擇材料配對、考慮加工工藝及熱處理,然后計算出各擋齒輪的轉(zhuǎn)矩。..軸的設(shè)計與計算及軸承的選擇與校核軸的設(shè)計計算軸的工藝要求倒擋軸為壓入殼體孔中并固定不動的光軸。變速器第二軸視結(jié)構(gòu)不同,可采用滲碳、高頻、氰化等熱處理方法。對于只有滑動齒輪工作的第二軸可以采用氰化處理,但對于有常嚙合齒輪工作的第二軸應(yīng)采用滲碳或高頻處理。第二軸上的軸頸常用做滾針的滾道,要求有相當高的硬度和表面光潔度,硬度應(yīng)在HRC58～63,表面光潔度不低于▽8。對于做為軸向推力支承或齒輪壓緊端面的軸的端面,光潔度不應(yīng)低于▽7,并規(guī)定其端面擺差。一根軸上的同心直徑應(yīng)可控制其不同心度。對于采用高頻或滲碳鋼的軸,螺紋部分不應(yīng)淬硬,以免產(chǎn)生裂紋。對于階梯軸來說,設(shè)計上應(yīng)盡量保證工藝簡單,階梯應(yīng)盡可能少。初選軸的直徑傳動軸的強度設(shè)計只需按照扭轉(zhuǎn)強度進行計算,輸入軸軸頸〔3.1其中k為經(jīng)驗系數(shù)取4.0~4.6所以d=24.36~28.01mm取d=26mm圖3.1軸的示意圖軸的強度計算〔1軸的剛度驗算若軸在垂直面內(nèi)撓度為,在水平面內(nèi)撓度為和轉(zhuǎn)角為δ,可分別用式計算〔3.2〔3.3〔3.4式中：—齒輪齒寬中間平面上的徑向力〔N；—齒輪齒寬中間平面上的圓周力〔N；—彈性模量〔MPa,=2.1×105MPa；—慣性矩〔mm4,對于實心軸,；—軸的直徑〔mm,花鍵處按平均直徑計算；、—齒輪上的作用力距支座、的距離〔mm；—支座間的距離〔mm。軸的全撓度為mm?！?.5軸在垂直面和水平面內(nèi)撓度的允許值為=0.05～0.10mm,=0.10～0.15mm。齒輪所在平面的轉(zhuǎn)角不應(yīng)超過0.002rad。變速器中一擋所受力最大,故只需校核一擋處軸的剛度與撓度輸入軸剛度圖3.2輸入軸受力分析圖一擋齒輪所受力N,Nmm,,mmmm〔3.6=0.089mm〔3.7=0.109=-0.00032rad0.002rad〔3.8輸出軸剛度圖3.3輸出軸受力分析圖N,Nmm,,mmmm=0.061mm=0.138=0.0012rad0.002rad輸入軸的強度校核〔2軸的強度計算變速器在一檔工作時：對輸入軸校核：計算輸入軸的支反力：NNN已知：a=86.125mm；b=194.875mm；L=281mm；d=27mm,1、垂直面內(nèi)支反力對C點取矩,由力矩平衡可得到A點的支反力,即：〔3.9將有關(guān)數(shù)據(jù)代入〔3.9式,解得：=2950.34N同理,對A點取矩,由力矩平衡公式可解得：2、水平面內(nèi)的支反力由力矩平衡和力的平衡可知：〔3.10〔3.11將相應(yīng)數(shù)據(jù)代入〔3.10、〔3.11兩式,得到：3、計算垂直面內(nèi)的彎矩B點的最大彎矩為：N·mmN·mmN·mmB點的最小彎矩為：N·mm4、計算水平面內(nèi)的彎矩N·mm5、計算合成彎矩N·mmN·mm軸上各點彎矩如圖3.4所示：作用在齒輪上的徑向力和軸向力,使軸在垂直面內(nèi)彎曲變形,而圓周力使軸在水平面內(nèi)彎曲變形。在求取支點的垂直面和水平面內(nèi)的支反力之后,計算相應(yīng)的彎矩、。軸在轉(zhuǎn)矩和彎矩的同時作用下,其應(yīng)力為<3.12>式中：〔N.m；——軸的直徑〔mm,花鍵處取內(nèi)徑；——抗彎截面系數(shù)〔mm3。將數(shù)據(jù)代入〔3.12式,得：MPaMPa在低檔工作時,400MPa,符合要求。圖3.4輸入軸的強度分析圖對輸出軸校核：計算輸出軸的支反力：齒輪受力如下：NNN已知：a=86.125mm；b=194.875mm；L=281mm；d=40mm,對C點取矩,由力矩平衡可得到A點的支反力,即：〔3.13將有關(guān)數(shù)據(jù)代入〔3.13式,解得：=2800.76N同理,對A點取矩,由力矩平衡公式可解得：2、水平面內(nèi)的支反力由力矩平衡和力的平衡可知：〔3.14〔3.15將相應(yīng)數(shù)據(jù)代入〔3.14、〔3.15兩式,得到：3、計算垂直面內(nèi)的彎矩B點的最大彎矩為：N·mmN·mmN·mmB點的最小彎矩為：N·mm4、計算水平面內(nèi)的彎矩N·mm5、計算合成彎矩N·mmN·mm軸上各點彎矩如圖3.5所示：圖3.5輸出軸的彎矩圖作用在齒輪上的徑向力和軸向力,使軸在垂直面內(nèi)彎曲變形,而圓周力使軸在水平面內(nèi)彎曲變形。在求取支點的垂直面和水平面內(nèi)的支反力之后,計算相應(yīng)的彎矩、。軸在轉(zhuǎn)矩和彎矩的同時作用下,其應(yīng)力為<3.16>式中：〔N.m；——軸的直徑〔mm,花鍵處取內(nèi)徑；——抗彎截面系數(shù)〔mm3。將數(shù)據(jù)代入〔3.16式,得：MPaMPa軸承的選擇與校核3.2.1輸入軸軸承選擇與校核初選軸承型號根據(jù)機械設(shè)計手冊選擇30205型號軸承KN,KN和30206型號軸承KN,KN1、變速器一檔工作時軸承的徑向載荷：N,N軸承內(nèi)部軸向力〔查機械設(shè)計手冊得：Y=1.6：NNN所以NN計算軸承當量動載荷查機械設(shè)計手冊得到7,查機械設(shè)計手冊得到；,查機械設(shè)計手冊得到當量動載荷：NN為支反力。查表,根據(jù)壽命計算公式h合格合格3.2.2輸出軸軸承的選擇與校核1.初選軸承型號根據(jù)機械設(shè)計手冊選擇軸承型號為：右軸承采用30205型號KN,KN左軸承采用30206型號KN,KN變速器一檔工作時：齒輪上的力：軸承的徑向載荷：N,N軸承內(nèi)部軸向力：查機械設(shè)計手冊得：Y=1.6NNN所以NN計算軸承當量動載荷查機械設(shè)計手冊得到7,查機械設(shè)計手冊得到；,查機械設(shè)計手冊得到當量動載荷：NN為支反力。查表,根據(jù)壽命計算公式h合格合格本章小結(jié)本章首先簡要介紹了軸的工藝要求,即滿足工作條件的要求。通過計算,確定軸的最小軸頸,通過軸承等確定軸的軸頸和各階梯軸的長度,然后對軸進行剛度和強度的驗算校核。通過軸頸,選擇合適的軸承,通過軸向力的大小對軸承進行壽命計算。參考文獻[1]郝京順.汽車變速器的發(fā)展[J].知識講座,2000<6>．[2]楊通順．變速器的黃金時代[J]．汽車與配件,2003．[3]王尚軍.DC6J80T六檔變速器設(shè)計[J].XX齒輪集團XX公司,2002<1>．[4]林紹義.一種汽車變速器設(shè)計[J].機電技術(shù),2004<1>．[5]吳修義.國內(nèi)組合式機械變速器的現(xiàn)狀與發(fā)展[J].現(xiàn)代零部件,2005<1>．[6]吳修義.機械變速器系列化及與車輛的匹配[J].變通世界,1999<9>．[7]殷浩東.工程機械驅(qū)動橋、變速器產(chǎn)品現(xiàn)狀與發(fā)展分析[J].工程機械與維修,2006<4>．[8]張洪欣．變速器優(yōu)化設(shè)計[J]．XX工業(yè)大學出版社,2003．[9]王望予.汽車設(shè)計[M].北京：機械工業(yè)出版社,2003．[10]陳家瑞.汽車構(gòu)造[M].北京：機械工業(yè)出版社,2005．[11]吳際璋．汽車構(gòu)造[M]．北京：人民交通出版社,2004．[12]張陽,席軍強,陳慧巖.半掛牽引車自動變速器換檔策略研究[J].北京理工大學機械與車輛工程學院,2006<2>．[13]余志生.汽車理論[M]．北京：機械工業(yè)出版社,2000．[14]劉惟信.汽車設(shè)計[M].北京：清華大學出版社,2001．[15]王三民.諸問俊.機械原理與設(shè)計[M].北京：機械工業(yè)出版社,2001．[16]王世剛,張秀親,苗淑杰.機械設(shè)計實踐[M].XX：XX工程大學出版社,2001．致謝通過本次設(shè)計,使我對變速器有了更多的了解,明白了變速器設(shè)計的重要性對變速器的現(xiàn)狀及未來有了更深刻的了解,綜合運用了《汽車構(gòu)造》、《汽車理論》《汽車設(shè)計》、《機械設(shè)計》、《液壓傳動》等課程知識,鞏固了所學知識。在本次畢業(yè)設(shè)計中,指導老師蘇清源一直關(guān)注著我的每一步進展,并給了我很多的意見和建議,同時也對我提出了嚴格的要求,我能夠順利的完成畢業(yè)設(shè)計,和蘇老師的指導師分不開的,在此特別感謝蘇老師對我指導與幫助。另外,在這次畢業(yè)設(shè)計時,遇到很多問題,車輛工程老師和同學也給了我很大幫助,非常感謝幫助過我的老師與同學。附錄ManualtransmissionOverviewManualtransmissionsoftenfeatureadriver-operatedclutchandamovablegearsele——ctor.Mostautomobilemanualtransmissionsallowthedrivertoselectanyforwardgearratio<"gear">atanytime,butsome,suchasthosecommonlymountedonmotorcyclesandsometypesofracingcars,onlyallowthedrivertoselectthenext-higherornext-lowergear.Thistypeoftransmissionissometimescalledasequentialmanualtransmission.Sequentialtransmissionsarecommonlyusedinautoracingfortheirabilitytomakequickshifts.Manualtransmissionsarecharacterizedbygearratiosthatareselectablebylockingsel—ectedgearpairstotheoutputshaftinsidethetransmission.Conversely,mostautomatictr—ansmissionsfeatureepicyclic<planetary>gearingcontrolledbybrakebandsand/orclutchpackstoselectgearratio.Automatictransmissionsthatallowthedrivertomanuallyselectt—hecurrentgeararecalledManumatics.Amanual-styletransmissionoperatedbycompute—risoftencalledanautomatedtransmissionratherthananautomatic.Contemporaryautomobilemanualtransmissionstypicallyusefourtosixforwardgearsandonereversegear,althoughautomobilemanualtransmissionshavebeenbuiltwithasfewastwoandasmanyaseightgears.Transmissionforheavytrucksandotherheavyequipmentusuallyhaveatleast9gearssothetransmissioncanofferbothawiderangeofg—earsandclosegearratiostokeeptheenginerunninginthepowerband.Someheavyvehi—cletransmissionshavedozensofgears,butmanyareduplicates,introducedasanacciden—tofcombininggearsets,orintroducedtosimplifyshifting.Somemanualsarereferredtobythenumberofforwardgearstheyoffer<e.g.,5-speed>asawayofdistinguishingbetweenautomaticorotheravailablemanualtransmissions.Similarly,a5-speedautomatictransmissi—onisreferredtoasa"5-speedautomatic"TheearliestformofamanualtransmissionisthoughttohavebeeninventedbyLouisR—enéPanhardandEmileLevassorinthelate19thcentury.Thistypeoftransmissionoffere—dmultiplegearratiosand,inmostcases,reverse.Thegearsweretypicallyengagedbysli—dingthemontheirshafts—hencetheterm"shiftinggears,"whichrequiredalotofcarefultimingandthrottlemanipulationwhenshifting,sothatthegearswouldbespinningatrou—ghlythesamespeedwhenengaged;otherwise,theteethwouldrefusetomesh.Thesetransm—issionsarecalled"slidingmesh"transmissionsandsometimescalledacrashbox.Mostne—wertransmissionsinsteadhaveallgearsmeshatalltimesbutallowsomegearstorotatef—reelyontheirshafts;gearsareengagedusingsliding-collardogclutches;thesearereferre—dtoas"constant-mesh"transmissions.Inbothtypes,aparticulargearcombinationcanonlybeengagedwhenthetwopartstoengage<eithergearsordogclutches>areatthesamespeed.Toshifttoahighergear,thetran—smissionisputinneutralandtheengineallowedtoslowdownuntilthetransmissionpart—sforthenextgearareataproperspeedtoengage.Thevehiclealsoslowswhileinneutralandthatslowsothertransmissionparts,sothetimeinneutraldependsonthegrade,wind,a—ndothersuchfactors.Toshifttoalowergear,thetransmissionisputinneutralandtheth—rottleisusedtospeeduptheengineandthustherelevanttransmissionparts,tomatchspe—edsforengagingthenextlowergear.Forbothupshiftsanddownshifts,theclutchisrelea—sed<engaged>whileinneutral.Somedriversusetheclutchonlyforstartingfromastop,andshiftsaredonewithouttheclutch.Otherdriverswilldepress<disengage>theclutch,sh—ifttoneutral,thenengagetheclutchmomentarilytoforcetransmissionpartstomatchtheenginespeed,thendepresstheclutchagaintoshifttothenextgear,aprocesscalleddoubleclutching.Doubleclutchingiseasiertogetsmooth,asspeedsthatareclosebutnotquitem—atchedneedtospeeduporslowdownonlytransmissionparts,whereaswiththeclutche—ngagedtotheengine,mismatchedspeedsarefightingtherotationalinertiaandpoweroftheengine.Eventhoughautomobileandlighttrucktransmissionsarenowalmostuniversallysync—hronised,transmissionsforheavytrucksandmachinery,motorcycles,andfordedicatedr—acingareusuallynot.Non-synchronizedtransmissiondesignsareusedforseveralreasons.Thefrictionmaterial,suchasbrass,insynchronizersismorepronetowearandbreakagetha—ngears,whichareforgedsteel,andthesimplicityofthemechanismimprovesreliabilitya—ndreducescost.Inaddition,theprocessofshiftingasynchromeshtransmissionisslowerthanthatofshiftinganon-synchromeshtransmission.Forracingofproduction-basedtran—smissions,sometimeshalftheteeth<or"dogs">onthesynchrosareremovedtospeedtheshi—ftingprocess,attheexpenseofgreaterwear.ShaftsLikeothertransmissions,amanualtransmissionhasseveralshaftswithvariousgearsa—ndothercomponentsattachedtothem.Typically,arear-wheel-drivetransmissionhasthre—eshafts:aninputshaft,acountershaftandanoutputshaft.Thecountershaftissometimescalledalayshaft.Inarear-wheel-drivetransmission,theinputandoutputshaftliealongthesameline,a—ndmayinfactbecombinedintoasingleshaftwithinthetransmission.Thissingleshaftiscalledamainshaft.Theinputandoutputendsofthiscombinedshaftrotateindependently,atdifferentspeeds,whichispossiblebecauseonepieceslidesintoahollowboreintheotherp—iece,whereitissupportedbyabearing.Sometimesthetermmainshaftreferstojustthei—nputshaftorjusttheoutputshaft,ratherthantheentireassembly.Insometransmissions,it'spossiblefortheinputandoutputcomponentsofthemain—shafttobelockedtogethertocreatea1:1gearratio,causingthepowerflowtobypasstheco—untershaft.Themainshaftthenbehaveslikeasingle,solidshaft,asituationreferredtoasdirectdrive.Evenintransmissionsthatdonotfeaturedirectdrive,it'sanadvantagefortheinputan—doutputtoliealongthesameline,becausethisreducestheamountoftorsionthatthetra—nsmissioncasehastobear.Mostfront-wheel-drivetransmissionsfortransverseenginemountingaredesigneddifferently.Foronething,theyhaveanintegralfinaldriveanddifferential.Foranother,theyusuallyhaveonlytwoshafts;inputandcountershaft,sometimescalledinputandoutput.Theinputshaftrunsthewholelengthofthegearbox,andthereisnoseparateinputpinion.Attheendofthesecond<counter/output>shaftisapiniongearthatmateswiththeringgearonthedifferential.Front-wheelandrear-wheel-drivetransmissionsoperatesimilarly.Whenthetransmissionisinneutral,andtheclutchisdisengaged,theinputshaft,clutchdiskandcountershaftcancontinuetorotateundertheirowninertia.Inthisstate,theengine,theinputshaftandclutch,andtheoutputshaftallrotateindependently.ShiftmodeMainarticle:GearstickA5speedgearleverInmanymodernpassengercars,gearsareselectedbymanipulatingaleverconnectedtothetransmissionvialinkageorcablesandmountedontheflooroftheautomobile.Thisiscalledagearstick,shiftstick,gearshift,gearlever,gearselector,orshifter.Movingtheleverforward,backward,left,andrightintospecificpositionsselectsparticulargears.AnaftermarketmodificationofthispartisknownastheinstallationofashortshifterwhichcanbecombinedwithanaftermarketshiftknoborWeightedGearKnob.Asamplelayoutofafour-speedtransmissionisshownbelow.Nmarksneutral,thepositionwhereinnogearsareengagedandtheengineisdecoupledfromthevehicle'sdrivewheels.Inreality,theentirehorizontallineisaneutralposition,althoughtheshifterisusuallyequippedwithspringssothatitwillreturntotheNpositionifnotmovedtoanothergear.TheRmarksreverse,thegearpositionusedformovingthevehiclerearward.Thislayoutiscalledtheshiftpattern.Becauseoftheshiftquadrants,thebasicarrangementisoftencalledanH-pattern.Whilethelayoutforgearsonethroughfourisnearlyuniversal,thelocationofreverseisnot.Dependingontheparticulartransmissiondesign,reversemaybelocatedattheupperleftextentoftheshiftpattern,atthelowerleft,atthelowerright,orattheupperright.Thereisusuallyamechanismthatonlyallowsselectionofreversefromtheneutralposition,toreducethelikelihoodthatreversewillbeinadvertentlyselectedbythedriver.Thisisthemostcommonfive-speedshiftpattern:Thislayoutisreasonablyintuitivebecauseitstartsattheupperleftandworkslefttoright,toptobottom,withreverseattheendofthesequenceandtowardtherearofthecar.Thisisanotherfive-speedshiftpattern,whichcanbefoundinSaabs,BMWs,someAudis,Volvos,Volkswagens,Opels,Hyundais,mostRenaults,somedieselFords,andmore:Dog-legfirstshiftpatternsareusedonmanyracecarsandonolderroadvehicleswiththree-speedtransmissions:Thenamederivesfromtheup-and-overpathbetweenfirstandsecondgears.Itsuseiscommoninracecarsandsportscars,butisdiminishingassixspeedandsequentialgearboxesarebecomingmorecommon.Thisisatypicalshiftpatternforasix-speedtransmission:Thougheight-speedtransmissionsdoexist,sixforwardspeedsiswidelyconsideredtobethemaximumthatcanbecontainedwithinavariationofthe"H"shiftpattern.Insuchacase,Reverseisplacedoutsideofthe"H",withacantedshiftpath,topreventtheshiftleverfromintrudingtoofarintothedriver'sspace<inleft-handdrivecars>whenreverseisselected.Thisisthemostcommonlayoutforasix-speedmanualtransmission.Mostfront-engined,rear-wheeldrivecarshaveatransmissionthatsitsbetweenthedriverandthefrontpassengerseat.Floor-mountedshiftersareoftenconnecteddirectlytothetransmission.Front-wheeldriveandrear-enginedcarsoftenrequireamechanicallinkagetoconnecttheshiftertothetransmission.References1."Synchronizers;graphicillustrationofhowtheywork"..Retrieved2007-07-18.

2.abU.S.DepartmentofEnergyvehiclefueleconomywebsite3.AnOverviewofCurrentAutomatic,ManualandContinuouslyVariableTransmissionEfficienciesandTheirProjectedFutureImprovements,KlugerandLong,SAE1999-01-12594.AnInvestigationintoTheLossMechanismsassociatedwithaPushingMetalV-BeltContinuouslyVariableTransmission,SamAkehurst,2001,Ph.DThesis,UniversityofBath.5.Ric