【正文】 一個剛性整體外殼或空心梁。整體鑄造式橋殼的強度和剛度較大，但質(zhì)量大，加工面多，制造工藝復雜，主要用于中、重型貨車上。鋼板沖壓焊接式和擴張成形式橋殼質(zhì)量小，材料利用率高，制造成本低，適用用于大量生產(chǎn)，結(jié)構(gòu)簡單，制造工藝性好，主減速器支承剛度好，拆裝、調(diào)整、維修方便，廣泛用于轎車和中、小型貨車上。分段式橋殼比整體式易于鑄造，加工簡便，但維修不方便 。 本次設計為中型貨車驅(qū)動橋設計。 汽車以最大牽引力行駛時的橋殼強度計算作用在左右驅(qū)動車輪上的轉(zhuǎn)矩所引起的地面對左、右驅(qū)動車輪的最大切向反作用力共為 = （51）式中：——發(fā)動機最大轉(zhuǎn)矩，N==驅(qū)動橋殼承受著水平方向的彎矩為= Nm橋殼還承受因驅(qū)動橋傳遞驅(qū)動轉(zhuǎn)矩而引起的反作用力矩，這時在兩鋼板彈簧座間橋殼承受的轉(zhuǎn)矩為 = Nm ——傳動系的最低擋傳動比； —傳動系的傳動效率。m危險斷面處為圓管形則 從而危險斷面處靜彎曲應力為 通過以上計算說明本方案設計的橋殼滿足強度要求。mm；——軸的抗扭載面模量，≈；——主動齒輪軸的初選值。=34MPa滿足≤［］＝30～40MPa　、從動齒輪上的力軸向力： =(　　　　　　　　?。?2）=(　　　　　　　　徑向力： 　　　 ()　　　　　　　（63）()式中：——主動齒輪齒面寬中點處的圓周力＝N/mm； ——從動齒輪齒面寬中點處的圓周力=N/mm； 式中：——作用在主動齒輪上的轉(zhuǎn)矩，=15159N；——該齒輪齒面寬中點的分度圓直徑，=320mm；＝N==——主動齒輪輪齒兩側(cè)法向壓力角, =176。；——主動齒輪的中點螺旋角，=176?！鲃育X輪的面錐角，=176。；——主動齒輪的節(jié)錐角，=176。=(==(=()=()= 圖61 軸承載荷分析如上圖所示主動齒輪則主動齒輪軸承的徑向載荷為 （64） 則第二級軸承得徑向載荷為當量動載荷計算：Q=XR+YA　　　　　　　　　　　　　　　　　　　　　　?。?5）式中：X是徑向系數(shù)； Y是軸向系數(shù)；軸承壽命計算：　　　　　　　　　　　　　　　　?。?6）式中：C————額定動載荷N； ————溫度系數(shù)； ————載荷系數(shù)；對于車輛=~ ————壽命指數(shù)；對于滾子軸承主動齒輪的軸承壽命計算：==1925871Km第二級的軸承壽命計算：==1255922Km==2595978Km通過以上計算說明本方案所設計的軸承的壽命均達到了汽車行業(yè)所規(guī)定的載貨汽車的軸承壽命不低于250000Km的要求.結(jié)論本次設計是對中型貨車驅(qū)動橋為研究對象，對驅(qū)動橋、主減速器、差速器、半軸、橋殼布置進行了設計及計算。并應用MATLAB軟件進行編程。二、設計內(nèi)容：1. 主減速器和差速器的設計在主減速器和差速器的設計中，參數(shù)的選取和計算按照劉惟信主編的《汽車設計》中的計算方法。差速器的設計方法和思路與主減速器的設計基本類似，本次設計選用了工作平穩(wěn)、結(jié)構(gòu)簡單的普通錐齒輪式差速器。此部分對驅(qū)動橋殼的功用和結(jié)構(gòu)方案進行了介紹和分析，采用整體式橋殼，因為其具有較大的強度和剛度，拆裝、調(diào)整方便等優(yōu)點。參考文獻[1] 劉惟信. : 清華大學出版社, 2001[2] 王望予. 汽車設計（: 機械工業(yè)出版社, [3] 陳家瑞. 汽車構(gòu)造（第4版. 北京: 人民交通出版社, [4] 張洪欣 . 汽車設 .北京：機械工業(yè)出版社 . 1999 [5] 紀峻嶺. 傳動軸、差速器、驅(qū)動橋及車橋. 北京: 化學工業(yè)出版社, 2005[6] 汽車標準匯編（第四卷）. 中國汽車技術(shù)中心, 2004 [7] 郝京順. 汽車設計標準資料手冊. 長春: 吉林科技出版社, 1992[8] 吳克堅. 機械設計. 北京: 高等教育出版社, 2003[9] 孫恒, （第六版）. 北京: 高等教育出版社, 2001 [10] 孫志禮. : 東北大學出版社, [11] 龔微寒 . ：人民交通出版社 . 1995 [12] 劉維信. 圓錐齒輪與雙曲面齒輪傳動. 北京：人民交通出版社， 1980[13] 頓德安. , 2000[14] 張玉， 劉平. : 東北大學出版社, [15] 齒輪手冊編委會. 齒輪手冊(第二版).北京：機械工業(yè)出版社， [16] 吉林工業(yè)大學汽車教研室 . ：機械工業(yè)出版社 . 1981[17] 機械設計手冊編委會. 機械設計手冊(3).北京: 機械工業(yè)出版社, [18] 小林明. 汽車工程手冊 (第二分冊).北京: 機械工業(yè)出版社, 1984[19] Reimpell J, stoll H. The Automotive Chassis: Engineering Principles. Warremdale, PA 15096, SA, SAE, 1996 致謝大學四年的美好生活即將以這篇畢業(yè)論文劃上一個句號，回首這段畢業(yè)設計過程，心中滿是感恩之情，在此特地表達誠摯的謝意。我要感謝我的指導教師XXX老師。他的治學嚴謹?shù)膽B(tài)度、謙虛扎實的工作作風使我深受教育和啟迪，讓我深深感覺到教師的偉大。最后說聲，XXX老師，您辛苦了！最后，我要感謝我的同學和朋友。在這次設計即將完成之際，我要忠心的謝謝你們！附 錄1Differential and Rear AxlesThe differential is part of the rearaxlehousing assembly, which includes the differential, rear axles, wheels, and bearings. If the car were to be driven in a straight line without having to make turns, then no differential would be necessary. However, when the car rounds a turn, the outer wheel must travel farther than the inner wheel. The differential permits the two rear wheels to rotate different amounts when the car goes around a turn, while still delivering power to both rear wheels.The rear axles are attached to the wheels and have bevel side gears on their inner ends. The differential case is assembled on the left axle but can rotate on a bearing independently of the differential case supports the differentialpinion gear on a shaft, and this gear meshes with the two bevel gears. The ring gear is attached to the differential case so that the case rotates with the ring gear when the later is driven by the drive driving power enters the differential through the drive pinion on the end of the propeller shaft. The drive pinion is meshed with a large ring gear so that the ring gear revolves with the pinion.Attached to the ring gear (through the differential case) is a differentialpinion shaft on which are assembled two differentialpinion gears. Each rear car wheel has a separate axle, and there are two side gears splined to the inner ends of the two wheel axles. The two differentialpinion gears mesh with these two side gears. When the car is on a straight road, the two differentialpinion gears do not rotate on the pinion shaft, but they do exert pressure on the two side gears so that the side gears turn at the same speed as the ring gear, causing both rear wheels to turn at the same speed, differential case is supported in the carrier by two taperedroller side bearings. This assembly can be adjusted from side to side to provide the proper backlash between the ring gear and pinion and the required side bearing preload. This adjustment is achieved by threaded bearing adjusters on some units and the placement of selective shims and spacers on others.The differential case is supported in the carrier by two taperedroller side bearings. This assembly can be adjusted from side to side to provide the proper backlash between the ring gear and pinion and the required side bearing preload. This adjustment is achieved by threaded bearing adjusters on some units and the placement of selective shims and spacers on others.Transaxle final drive gears provide the means for transmitting transmission output torque to the differential section of the transaxle. The differential section of the transaxle has the same ponents as the differential gears in a RWD axle and basically operate in the same way. The power flow in transversely mounted power trains is in line with the wheels and therefore the differential unit does not need to turn the power 90 degrees.When the car rounds a curve, the outer wheel must turn faster than the inner wheel. To permit this, the two pinion gears rotate on their pinion shaft, transmitting more turning movement to the outer side gear than to the inner side gear. Thus, the side gear on the outerwheel axle turns more rapidly than the side gear on the innerwheel axle. This permits the outer wheel to turn more rapidly while the car is rounding the are two basic types of axle: dead axles and live axle. The dead axle does not ro