【正文】 tion, etc. to control exact shift points as well as how soft or firm the shift should be. Once the puter receives this information, it then sends signals to a solenoid pack inside the transmission. The solenoid pack contains several electrically controlled solenoids that。t move. In this scenario, when we turn the ring gear, the plas will walk along the sun gear (which is held stationary) causing the pla carrier to mm the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction (similar to a car in first gear). If we unlock the sun gear and lock any two elements together, this will cause all three elements to turn at the same speed so that the output shaft will mm at the same rate of speed as the input shaft. This is like a car that is in third or high gear. Another way that we can use a Plaary gear set is by locking the pla carrier from moving, then applying power to the ring gear which will cause the sun gear to turn in the opposite direction giving us reverse gear. The clutch pack is used, in this instance, to lock the pla carrier with the sun gear forcing both to turn at the same speed. If both the clutch pack and the band were released, the system would be in neutral. Turning the input shaft would turn the pla gears against the sun gear, but since nothing is holding the sun gear, it will just spin free and have no effect on the output shaft. To place the unit in first gear, the band is applied to hold the sun gear from moving. To shift from first to high gear, the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft. Many more binations are possible using two or more plaary sets connected in various ways to provide the different forward speeds and reverse that are found in modem automatic transmissions. Some of the clever gear arrangements found in four and now, five, six and even sevenspeed automatics are plex enough to make a technically astute lay person39。s dynamic performance. It is usually required shifting gears rapidly and conveniently, saving force, and having a higher working efficiency and low working noises.The modern automatic transmission is by far, the most plicated mechanical ponent in today39。由于各位老師的幫助，使我們對(duì)畢業(yè)設(shè)計(jì)更加感興趣，使我們更加有信心地完成這次的畢業(yè)設(shè)計(jì)。通過(guò)本次設(shè)計(jì)，使所設(shè)計(jì)的變速器工作可靠，傳動(dòng)效率更高。為了使得汽車能夠適應(yīng)于不同工程的需要，使得汽車的應(yīng)用范圍更加的廣泛，本變速器帶有取力器。變速器采用中間軸式, 換檔形式采用的是同步器換檔和滑移齒輪換擋。mm）gK —齒寬系數(shù)cK —應(yīng)力集中系數(shù)，直齒輪 K =? ? 斜齒輪 K =K —重合度影響系數(shù)，主動(dòng)齒輪 K = 從動(dòng)齒輪 K = f fK —重合度影響系數(shù)，K =2? ?y—齒形系數(shù)取力器一軸雙聯(lián)齒輪二級(jí)齒輪的校核 mNTg??390max4???K1.?fb=25 ? 2472893max?dMFet N/mm N/?ybKFtfw? ??80~?2所以強(qiáng)度合格。取力器軸的強(qiáng)度計(jì)算：軸在垂直面內(nèi)撓度為 ，水平面為 ，轉(zhuǎn)角為 ，cfsf? ； ； ；EILbaFfc321?EILbaFs32???EILabF31??～為輪齒齒寬在中間平面上的圓周力。我所設(shè)計(jì)的取力器采用雙聯(lián)齒輪，同時(shí)考慮窗口的尺寸與形狀。其中中置式取力器又包括變速器上蓋取力、變速器側(cè)蓋取力、變速器后蓋取力。再有就是可實(shí)現(xiàn)系列化，盡量能滿足三化的要求。當(dāng)?shù)箵鯎懿孑S移動(dòng)掛擋時(shí)，另外兩個(gè)撥叉軸被鋼球瑣住?；ユi鎖裝置 ：當(dāng)中間換擋撥叉軸移動(dòng)掛擋時(shí)，另外兩個(gè)撥叉軸被鋼球瑣住。在振動(dòng)等條件影響下，操縱機(jī)構(gòu)應(yīng)保證變速器不自行掛擋或自行脫擋。直接操縱手動(dòng)換擋變速器：當(dāng)變速器布置在駕駛員座椅附近，可將變速桿直接安裝在變速器上，并依靠駕駛員手力和通過(guò)變速桿直接完成換擋功能的手動(dòng)換擋變速器，稱為直接操縱變速器。在振動(dòng)等條件影響下，操縱機(jī)構(gòu)應(yīng)保證變速器不自行掛擋或自行脫擋。軸的全撓度為 ； 2scff??在其作用下應(yīng)力為 3dMW??M～ ，W～為抗彎截面系數(shù)。二軸、中間軸最大直徑可取 d== 126==57mm?中間軸： d/L= 取為 L=315mm二軸： d/L= 取為 L=315mm軸在垂直面內(nèi)撓度為 ，在水平面為 ，轉(zhuǎn)角為 ，則cfsf? ； ； ；EILbaFfc321?EILbaFs32???EILabF31??為輪齒齒寬在中間平面上的圓周力， 為齒輪齒寬在中間面上的徑向力。為了防止變速器在工作中自動(dòng)脫檔,高通用性,有時(shí)變速器中幾組鎖銷式同步器要選用相同的同步器。6 齒套鎖銷孔和定位銷空的設(shè)計(jì)一般鎖銷孔的數(shù)量為 3 個(gè)～6 個(gè),中型車變速器取小值,重型車變速器取大值。根據(jù)摩擦錐面平均半徑 R 錐、摩擦系數(shù) μ、錐面角 α 和撥環(huán)半徑 R 鎖來(lái)確定合適的鎖銷角 β,通常取 β=35176。同步環(huán)錐面寬 B 與摩擦錐面的發(fā)熱有關(guān),一般取 B=R鎖/10～R 鎖/14(R 鎖為撥環(huán)半徑)。一般油槽寬為 2mm～4mm,數(shù)量 30 個(gè)～40 個(gè)。同步齒輪 摩擦錐盤 摩擦錐環(huán) 定位銷接合套 接合齒圈 鎖銷 花鍵轂 9。　　接合套、同步鎖環(huán)和待接合齒輪的齒圈上均有倒角（鎖止角），同步鎖環(huán)的內(nèi)錐面與待接合齒輪齒圈外錐面接觸產(chǎn)生摩擦。為了簡(jiǎn)化操作，并避免齒間沖擊，可以在換擋裝置中設(shè)置同步器。而輸入端在接觸錐面上產(chǎn)生的摩擦力矩作用下,克服輸入端被接合零件的等價(jià)慣性力矩,在最短時(shí)間內(nèi)使輸入端與輸出端的轉(zhuǎn)速達(dá)到同步?？紤]盡量減少軸向尺寸和質(zhì)量，齒寬應(yīng)小些，但齒輪傳動(dòng)平穩(wěn)性消弱，此時(shí)雖然可以用增加齒輪螺旋角來(lái)補(bǔ)償，但這時(shí)軸承的軸向力增大，使之壽命降低，齒寬窄還會(huì)使齒輪的工作應(yīng)力增加，選用寬些的齒寬，工作時(shí)因軸的變型導(dǎo)致沿齒寬方向受力不均勻并在齒寬方向磨損不均勻。而對(duì)于斜齒輪 ， 是當(dāng)量直齒標(biāo)準(zhǔn)齒輪不發(fā)生根切的i ?3cosvminvZ最小齒數(shù)。～26176。其次，斜齒輪傳遞轉(zhuǎn)矩時(shí)，要產(chǎn)生軸向力。選取斜齒輪的螺旋角應(yīng)注意以下問(wèn)題：首先，增大 β 角使齒輪嚙合的重合系數(shù)增加，工作平穩(wěn)、噪聲降低。降低噪聲對(duì)轎車有意義，減輕質(zhì)量對(duì)貨車比較重要。第三章 變速器各主要參數(shù)的設(shè)計(jì)計(jì)算 變速器傳動(dòng)比的確定（1）由最大爬坡度要求的變速器一檔轉(zhuǎn)動(dòng)比又 ， ， ，tmaxfiaxF=+emax10taxMiF=r?fmaxF=gcos?iamaxF=fgsin?則 e10aaxMgfcos+inr????（ ） 34i3??輪胎型式取 255/70R45140/137J 12in= 則即半徑為 ， ， ， ，=.9?=???m=9800kgm汽車總質(zhì)量g重力加速度max?道路最大阻力系數(shù)r驅(qū)動(dòng)車輪的滾動(dòng)半徑axeT為發(fā)動(dòng)機(jī)最大轉(zhuǎn)矩0i主減速比傳動(dòng)系的傳動(dòng)效率?（2）根據(jù)驅(qū)動(dòng)輪與路面的附著力確定一檔傳動(dòng)比 emax10MiNr?? ==?? N 驅(qū)動(dòng)輪垂直反力 取整車重量的 65% =～ 道路附著系數(shù) 取 ?由（1） 、 （2）相比較取較小的 故一檔傳動(dòng)比確定為： 1i= 其它各檔位的傳動(dòng)比而 ==165各檔傳動(dòng)比： 1maxi? 23q29 5465 min?1i而 .?各檔之比都小于 ～ 故合格 中心距的初步確定初選中心矩可用下式計(jì)算 取整 A=?????式中：A——中心距系數(shù)， 取值范圍 — 取 A=9AKaxeT——發(fā)動(dòng)機(jī)最大轉(zhuǎn)矩， NmTe3ax1i——變速器一擋傳動(dòng)比， ?——變速器傳動(dòng)效率， ?096?求得 A=126mm 軸的直徑的初步確定變速器的軸必須有足夠的剛度和強(qiáng)度。我目前的方案為除了變速器二軸長(zhǎng)嚙合齒輪與二軸之間的軸承以及取力器一軸采用滾針軸承外，其余的軸承均采用深溝球軸承。但結(jié)構(gòu)復(fù)雜、制造精度要求高、軸向尺寸大，多用于轎車和輕型貨車。（3）換擋型式：有直齒滑動(dòng)齒輪換擋、嚙合套換擋和同步器換擋三種型式。綜上所述中型專用汽車應(yīng)選用三軸式變速器。因此，直接擋的傳遞效率高，磨損及噪聲也最小，這是三軸式變速器的優(yōu)點(diǎn)。所以應(yīng)從齒輪的形式，軸的形式及布置的合理性等多方面分析，得到最佳方案。由于每擋齒輪組的齒數(shù)是固定的,所以各擋的變速比是定值。實(shí)現(xiàn)空擋,中斷發(fā)動(dòng)機(jī)傳遞給車輪的動(dòng)力,使發(fā)動(dòng)機(jī)能夠起動(dòng)、怠速。在這種情況下，傳動(dòng)裝置的設(shè)計(jì)，不但要滿足動(dòng)力性和經(jīng)濟(jì)性指標(biāo)，而且要求結(jié)構(gòu)緊湊、尺寸小、重量輕、傳動(dòng)效率高、工作可靠、壽命長(zhǎng)、噪音低等。s dynamic performance. It is usually required shifting gears rapidly and conveniently, saving force, and having a higher working efficiency and low working noises.The design of the five forward file plus a reverse of the transmission mediumsized special vehicle. In order to make the transmission more broad range of applications, application to a different project, make a check of the power transmission device. Transmission use of the middle axis, shifting the form of using the synchronizer gear shift and sliding to make the shift easy and reliable. Manipulation of institutions with selflocking and interlocking devices.Using the given basic parameters, it was firstly determined the transmission ratio of each shift, the shaft center distances, the gear modu