【正文】 這兩個(gè)差速副齒輪和兩個(gè)邊緣齒輪互相咬合。環(huán)行齒輪上（穿過差速裝置）是一個(gè)差速副齒輪柄，柄上是兩個(gè)差速副齒輪。通過驅(qū)動力作用于副齒輪的柄上，驅(qū)動力進(jìn)入差速器。差速器能使差速副齒輪作用于一個(gè)柄上，齒輪和兩個(gè)斜齒輪互相咬合。后車軸和輪子相連，并且在內(nèi)部的終端有傾斜齒輪。然而，車轉(zhuǎn)彎時(shí)，外面輪子的速度必須比里面的輪子快。 the wheel rotates on it. A mon example is the axle on a horse drawn wagon. Live axles are attached to the wheel so that both the wheel and the axle rotate together. Live axles are classified according to the manner in which they are supported: semifloating, threequarterfloating, and fullfloating.Propeller Shaft and Universal JointThe propeller shaft is a drive shaft to carry the power from the transmission to the rearwheel axles. It connects the transmission main, shaft carries through the propeller shaft to the differential at the rear axles. Rotary motion of the transmission main shaft carries through the propeller shaft to the differential, causing the rear wheels to rotate.The propellershaft design must take two facts into consideration. First, the engine and transmission are more or less rigidly attached to the car frame. Second, the rearaxle housing (with wheels and differential) is attached to the frame by springs. As the rear wheels encounter irregularities in the road, the springs press or expand. This changes the angle of drive and the distance between the transmission and the differential, and the propeller shaft may take care of these two changes. That is to say, as the rear axle housing, with differential and wheels, moves up and down, the angel between the transmission output shaft changes. The reason the propeller shaft shortens as the angel increases is that the rear axle and differential move in a shorter arc than the propeller shaft. The center point of the axlehousing arc is the rearspring or controlarm attachment to the frame. In order that the propeller shaft may take care of these two changes, it must incorporate two separate types of device. There must be one or more universal joints to permit variations in the angel of drive. There must also be a slip joint that permits the effective length of the propeller shaft to change.The propeller shaft may be solid or hollow, protected by an outer tube or exposed. Some applications include bearings at or near the propeller shaft center to support the shaft. The twosection propeller is supported by a center bearing and coupled together by universal joints. A universal joint is essentially a double hinged joint consisting of two Yshaped yokes, one on the driving shaft and the other on the driven shaft, and acrossshaped member called the spider. The four arms of the spider, known as trunnions, are assembled into bearings in the ends of the two shaft yokes. The driving shaft causes the spider to rotate, and the other two trunnions of the spider cause the driven shaft to rotate. When the two shafts are at an angel to each other, the bearings in the yokes permit the yokes to swing around on the trunnions with each revolution. A variety of universal joints have been used on auto mobiles, but the types now in most mon use are the spider and twoyoke, the constantvelocity, and the ballandtrunnion joints.A slip joint consists of outside splines on one shaft and matching internal splines in the mating hollow shaft, the splines cause the two shafts to rotate together but permit the two to move endwise with each other. This acmodates any effective change of length of the propeller shaft as the rear axles move toward or away from the car frame.差速器和后車軸差速器是后車軸體系的一部分，此體系包括差速器，后車軸，輪子和軸承。他們每天都和我一樣忙著畢業(yè)設(shè)計(jì)，但我有不會的地方請教時(shí)，他們馬上放下自己的設(shè)計(jì)幫我解除困雉。在每一次答疑的時(shí)候，他總是耐心地給我解答并將問題擴(kuò)展開來，讓我對其能夠真正的理解和掌握，讓我學(xué)到了好多知識，從中我看到了他淵博的知識和豐富的實(shí)際經(jīng)驗(yàn)。從設(shè)計(jì)題目的選擇到設(shè)計(jì)的完成，張老師都滲透了不少心血。在本設(shè)計(jì)完成之際，我要對多年幫助我的老師、同學(xué)和朋友表示忠心的感謝，是他們的關(guān)心和幫助給了我很大的動力，讓我更加順利的完成這次設(shè)計(jì)。綜上所述，本次設(shè)計(jì)基本達(dá)到預(yù)期目標(biāo)，完成了規(guī)定的任務(wù)。中型貨車采用全浮式半軸，從而確定了半軸的尺寸和材料，并對半軸進(jìn)行了強(qiáng)度計(jì)算。在主減速器設(shè)計(jì)中，首先對幾種主減速器進(jìn)行了比較，確定最終的主減速器形式，然后按照書中的設(shè)計(jì)方法進(jìn)行了有關(guān)參數(shù)確定計(jì)算，并進(jìn)行了校核，設(shè)計(jì)結(jié)果基本符合要求。 一、設(shè)計(jì)方案：我選擇了切實(shí)可行的方案，采用雙級雙曲面齒輪主減速器，提高了齒輪工作平穩(wěn)性，齒輪的接觸強(qiáng)度和彎曲強(qiáng)度，由于偏移距的存在，在保證一定離地間隙的情況下，可盡量使車身重心降低，有利于提高汽車行使平順性。并繪制了主減速器的裝備圖以及十字軸和從動錐齒輪的零件圖。主動齒輪的軸承壽命計(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的要求。=≤［］＝30～40MPa　、從動齒輪上的力軸向力： =(　　　　　　　 =(　　　　　　　　徑向力： 　 ()　　　　　　　()＝ = 式中：——主動齒輪齒面寬中點(diǎn)處的圓周力； ——從動齒輪齒面寬中點(diǎn)處的圓周力； ——作用在主動齒輪上的轉(zhuǎn)矩；——該齒輪齒面寬中點(diǎn)的分度圓直徑；——主動齒輪輪齒兩側(cè)法向壓力角；——從動齒輪輪齒兩側(cè)平均壓力角；——主動齒輪的中點(diǎn)螺旋角；——從動齒輪的中點(diǎn)螺旋角；——主動齒輪的根錐角；——從動齒輪的根錐角；——主動齒輪的節(jié)錐角；——從動齒輪的節(jié)錐角。 第6章 軸承的壽命計(jì)算1. 主動齒輪軸的強(qiáng)度計(jì)算對只承受轉(zhuǎn)矩或主要承受轉(zhuǎn)矩作用的傳動軸，其強(qiáng)度條件為≤［］　　　　　　　　　　　式中：——軸的扭剪應(yīng)力；——軸傳遞的轉(zhuǎn)矩；——軸的抗扭載面模量，≈；——主動齒輪軸的初選值。==驅(qū)動橋殼承受著水平方向的彎矩：= =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(shí)在兩鋼板彈簧座間橋殼承受的轉(zhuǎn)矩：= 式中：——發(fā)動機(jī)最大轉(zhuǎn)矩； ——傳動系的最低擋傳動比； —傳動系的傳動效率。 本次設(shè)計(jì)為中型貨車驅(qū)動橋設(shè)計(jì),采用鑄造整體式橋殼。分段式橋殼比整體式易于鑄造，加工簡便，但維修不方便 。鋼板沖壓焊接式和擴(kuò)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。整體鑄造式橋殼的強(qiáng)度和剛度較大，但質(zhì)量大，加工面多，制造工藝復(fù)雜，主要用于中、重型貨車上。1）整體式橋殼的結(jié)構(gòu)特點(diǎn)是一個(gè)剛性整體外殼或空心梁。5）在選擇橋殼的結(jié)構(gòu)型式時(shí)，還應(yīng)考慮汽車的類型、使用要求、制造條件和材料供應(yīng)等。3）結(jié)構(gòu)簡單，制造方便，以利于降低成本。驅(qū)動橋的設(shè)計(jì)應(yīng)滿足如下要求：1） 減小汽車的非簧載質(zhì)量以利于降低動載荷和提高汽車的行駛平順性。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。=16/=≤[]=490～588MPa 半軸桿部直徑：=(～) ==49mm式中： d——半軸桿部直徑； ——半軸的計(jì)算轉(zhuǎn)矩。全浮式半軸的計(jì)算載荷可按車輪附著力矩計(jì)算= 式中：、 見（22）（23）。全浮式半軸主要用于總質(zhì)量較大的商用車上。半軸根據(jù)其車輪端的支承方式不同，可分為半浮式、3/4浮式和全浮式。=第4章 車輪傳動裝置的設(shè)計(jì)接受從差速器傳來的轉(zhuǎn)矩并傳給驅(qū)動車輪。=（24）弦齒高： = +cos=+[60]176。（21）理論弧齒厚： === =/2() tan=() tan22176。= =+2cos=100+2=（20）節(jié)錐頂點(diǎn) =/2 sin=100/176。=176。= =176。176。=176。=+=176。+176。 =arctan(/)=arctan()=176。=arctan(/)=arctan(20/12)=176。30′（8）軸交角： ∑=90176。=2/(4205)= MPa＜980MPa符合要求。6）行星齒輪軸直徑及及支撐長度L通常取