【正文】 在這次設(shè)計(jì)即將完成之際，我要忠心的謝謝你們！ 附 錄 1 Differential and Rear Axles The 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 rotate。最后說聲， XXX 老師，您辛苦了！ 最后，我要感謝我的同學(xué)和朋友。他的治學(xué)嚴(yán)謹(jǐn)?shù)膽B(tài)度、謙虛扎實(shí)的工作作風(fēng)使我深受教育和啟迪，讓我深深感覺到教師的偉大。 我要感謝我的指導(dǎo)教師 XXX 老師。 軸承載荷的計(jì)算 圖 61 軸承載荷分析 如上圖所示主動(dòng)齒輪則 軸承的徑向載荷為 則徑向載荷為 主動(dòng)齒輪軸承壽命計(jì)算 當(dāng)量動(dòng)載荷計(jì)算： Q XR+YA （ 65） 式中： X 是徑向系數(shù)； Y 是軸向系數(shù)； 軸承壽命計(jì)算： （ 66） 式中： C――――額定動(dòng)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(dòng)齒輪的軸承壽命計(jì)算： 1925871Km 第二級的軸承壽命計(jì)算： 1255922Km 2595978Km 通過以上計(jì)算說明本方案所設(shè)計(jì)的軸承的壽命均達(dá)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. 結(jié)論 本次設(shè)計(jì)是對中型貨車驅(qū)動(dòng)橋?yàn)檠芯繉ο?，對?qū)動(dòng)橋、主減速器、差速器、半軸、橋殼 Reimpell J, stoll H. The Automotive Chassis: Engineering Principles. Warremdale, PA 15096, SA, SAE, 1996 致謝 大學(xué)四年的美好生活即將以這篇畢業(yè)論文劃上一個(gè)句號，回首這段畢業(yè)設(shè)計(jì)過程，心中滿是感恩之情，在此特地表達(dá)誠摯的謝意。； ――主動(dòng)齒輪的節(jié)錐角， 176。 ――主動(dòng)齒輪的面錐角， 176。； ――主動(dòng)齒輪的中點(diǎn)螺旋角， 176。 34MPa 滿足≤〔〕＝ 30～ 40MPa 、從動(dòng)齒輪上的力 軸向力： （ 62） 徑向力： （ 63） 式中： ――主動(dòng)齒輪齒面寬中點(diǎn)處的圓周力 ＝ N/mm； ――從動(dòng)齒輪齒面寬中點(diǎn)處的圓周力 N/mm； 式中：――作用在主動(dòng)齒輪上的轉(zhuǎn)矩， 15159N； ――該齒輪齒面寬中點(diǎn)的分度圓直徑， 320mm； ＝ N ――主動(dòng)齒輪輪齒兩側(cè)法向壓力角 , 176。第 6 章 軸承的壽命計(jì)算 主減速器軸承的計(jì)算 主動(dòng)齒輪軸的強(qiáng)度計(jì)算 對只承受轉(zhuǎn)矩或主要承受轉(zhuǎn)矩作用的傳動(dòng)軸，其強(qiáng)度條件為 ≤〔〕 （ 61） 式中：――軸的扭剪應(yīng)力， MPa； ――軸傳遞的轉(zhuǎn)矩 , N??mm； ――軸的抗扭載面模量，≈ ； ――主動(dòng)齒輪軸的初選值。 驅(qū)動(dòng)橋殼承受著水平方向的彎矩為 N??m （ 52） ??m 橋殼還承受因驅(qū)動(dòng)橋傳遞驅(qū)動(dòng)轉(zhuǎn)矩而引起的反作用力矩，這 時(shí)在兩鋼板彈簧座間橋殼承受的轉(zhuǎn)矩為 N??m （ 53） 式中：――發(fā)動(dòng)機(jī)最大轉(zhuǎn)矩， N??m ――傳動(dòng)系的最低擋傳動(dòng)比； ―傳動(dòng)系的傳動(dòng)效率?？紤]其要有足夠的強(qiáng)度和剛度，具有一定的承載能力和離地間隙等方面，所以采用鑄造整體式橋殼。拆檢主減速器時(shí)，必須把整個(gè)驅(qū)動(dòng)橋從汽車上拆卸下來，目前已很少采用。 ，由螺栓連成一體。但其簧下質(zhì)量較大，對汽車的行駛平順性有不利的影響。按制造工藝的不同又可分為多種形式，常見的為整體鑄造、鋼板沖壓焊接式、中段鑄造兩端壓入鋼管和鋼管擴(kuò)張成形等形式。 驅(qū)動(dòng)橋殼結(jié)構(gòu)方案分析 驅(qū)動(dòng)橋殼從結(jié)構(gòu)上可分為整體式橋殼和分段橋殼兩類。 驅(qū)動(dòng)橋的設(shè)計(jì)應(yīng)滿足如下要求： 減小汽車的非簧載質(zhì)量以利于降低動(dòng)載荷和提高汽車的行駛平順性； 保證足夠的離地間隙； 3）結(jié)構(gòu)簡單，制造方便，以利于降低成本； 4 保證主減速器的拆裝、調(diào)整、維修和保養(yǎng)方便。由于硬化層本身的強(qiáng)度較高，加之在半軸表面形成大的殘余壓應(yīng)力，因此使半 軸的靜強(qiáng)度和疲勞強(qiáng)度大為提高，尤其是疲勞強(qiáng)度提高得更為顯著。近些年來采用高頻、中頻等感應(yīng)淬火的日益增多。本次設(shè)計(jì)半軸的材料選用 40MnB。 關(guān)于半軸的材料，過去大都采用含鉻的中碳合金鋼，如 40Cr、 40CrMnMo、35CrMnTi、 38CrMnSi、 42CrMo 等，后來推廣我國制出的的新鋼種如 40MnB 等作為半軸材料，效果很好。半軸的破壞形式多為扭轉(zhuǎn)疲勞破壞。 〈 157MPa 280MPa 全浮式半軸桿部直徑的初選 半軸桿部直徑： ～ （ 46） ≈ 52mm 式中 ： d――半軸桿部直徑， mm； T――半軸的計(jì)算轉(zhuǎn)矩， N??m； 靜扭安全系數(shù)： 滿足在 ～ 范圍內(nèi)。 390 N??m 半軸的強(qiáng)度計(jì)算 半軸扭轉(zhuǎn)應(yīng)力：