【正文】 ng or coasting. A higher to rque should be applied to the wheels to set an automobile in motion or move uphill with a full load than to keep it rolling after it gets under way on level stretches of the road, when inertia is high and tractive resistance is low. To meet these variable torque requirements, special gear boxes are used. Such gear boxes are called fixedratio transmissions.In a gear train consisting of a driving gear and a driven gear, the torque at the driven gear will increase as many times as the number of teeth of the driven gear is larger than that of the driving gear.The figure obtained by dividing the number of driven gear teeth by that of the driving gear is called gear ratio. If a train consists of several pairs of gears, the overall ratio is the product of the gear ratios of all the gear pairs in the train.To provide the different torques required under the varying operating conditionsof a vehicle, the transmission incorporates several pairs of gears with different gear ratios. If an intermediate gear is introduced between the driving gear and the driven gear, the rotation of the driven gear will be reversed.The transmission consists of a housing, an input shaft and gear, an output and gear, an idler shaft, a reverse gear, a cluster of gears and a gear shift mechanism.The cast iron housing has upper and side covers and bores for the installation of shafts. The bottom and side walls are provided with holes for filling and draining oil.The input shaft is made of steel integral with the driving gear and the rim. The front end of the input shaft is installed on the bearing in the bore of the crankshaft, while the rear end rotates in the bore of the front wall of the housing. The input shaft is arranged so that only the driving gear and the rim are acmodated inside the housing while the splined potion of the shaft protruding from the transmission carries the hub of the clutch driven disk. The output shaft is splined and rests with its front end on a roller bearing installed in the bore of the input shaft. The other end of the output shaft rotates in a ball bearing in the transmission housing wall. The output shaft splines carry the sliding gears. The output shaft is coaxial with the input shaft.The idler shaft carries a cluster of gears of different sizes. The cluster is mounted in the roller bearings on an axle or, together with the shaft, on bearings in the housing wall bores. The idler shaft constantly rotates with the input shaft because their gears are in constant mesh. The reverse gear(a single gear or a twogear cluster) rotates on an axle secured in the holes of the housing walls. The gear shift mechanism is designed for engaging gears, setting them neutral and engaging the reverse speed. The speeds are changed by shifting the gears or sleeves along the output shaft. The transmission type depends on the number of the sliding gears or sleeves. The transmission with two sliding gears or synchronizer sleeves is called tworange, with three gears, threerange. Depending on the number of forward speeds there are three,four and fivespeed transmissions. The gear shift mechanism is mounted on the top cover. The shift lever is arranged on the cover or on the bracket of the lever support.。根據(jù)向前的速度的大小，由5速度的變速器。 齒輪軸安放著一組不同齒數(shù)比的齒輪。變速器有機(jī)殼、輸入軸和齒輪、輸出軸和齒輪、惰輪軸、回轉(zhuǎn)齒輪、齒輪組及換檔機(jī)構(gòu)組成。變速器便是實(shí)現(xiàn)這些功能。當(dāng)發(fā)動(dòng)機(jī)速度增加時(shí)，滾輪的楔形物自動(dòng)進(jìn)入壓力盤和外殼之間，這樣離合器轉(zhuǎn)動(dòng)的越快，施加在壓力盤上的壓力便越大。 在Estick裝配中，壓力盤杠桿嚙合離合器盤而不是分離的。主氣缸供應(yīng)一個(gè)附有杯子的活塞。離合器外殼是一個(gè)鋼鐵沖壓，由螺釘裝載調(diào)速器上。 離合器是通過(guò)摩擦獲得運(yùn)行的。到活塞到達(dá)上止點(diǎn)時(shí)，氣缸內(nèi)被燃燒過(guò)的氣體被清除掉?；鸹ㄓ牲c(diǎn)火系統(tǒng)產(chǎn)生?？刂浦M(jìn)氣閥的凸輪的突出部分已經(jīng)從閥門下面移走。 如果整個(gè)循環(huán)過(guò)程需要四次活塞運(yùn)動(dòng)，那么該發(fā)動(dòng)機(jī)就叫做四沖程發(fā)動(dòng)機(jī)，或四行程發(fā)動(dòng)機(jī)。 閥門是通過(guò)發(fā)動(dòng)凸輪軸上的凸輪被打開(kāi)的。 在動(dòng)力產(chǎn)生的過(guò)程中燃料系統(tǒng)起著重要的作用，因?yàn)樗o發(fā)動(dòng)機(jī)氣缸提供汽油。（3） 傳動(dòng)系，它將來(lái)自發(fā)動(dòng)機(jī)的動(dòng)力（經(jīng)過(guò)離合器、調(diào)速器、傳動(dòng)軸、差分器和車軸）傳送到車輪。汽車發(fā)動(dòng)機(jī)廣泛地應(yīng)用于配有巨大動(dòng)力的機(jī)械中，如農(nóng)業(yè)、建筑業(yè)、制造業(yè)。汽車行業(yè)也匯聚了千千萬(wàn)萬(wàn)的人。（2） 框架，它支持發(fā)動(dòng)機(jī)、車輪、操縱和剎車系統(tǒng)，以及機(jī)身。然后動(dòng)力經(jīng)過(guò)傳動(dòng)系傳送到發(fā)動(dòng)機(jī)再到車輪，這樣車輪轉(zhuǎn)動(dòng)，汽車便開(kāi)始運(yùn)行。當(dāng)他們被打開(kāi)時(shí)，氣體可以流通到端口。凸輪軸通過(guò)齒輪或鏈條齒和齒條受到機(jī)軸的驅(qū)動(dòng)。 當(dāng)活塞在進(jìn)口端移到下止點(diǎn)時(shí)，進(jìn)氣閥關(guān)閉?；鸹ㄈ举|(zhì)上是兩個(gè)粗鋼絲電極。這時(shí)，活塞又一次被返回，它推動(dòng)氣缸內(nèi)被燃燒過(guò)的氣體。在裝配有手工傳動(dòng)的汽車系統(tǒng)中，這可以通過(guò)一個(gè)機(jī)械離合器獲得成功。 除了壓力盤和驅(qū)動(dòng)盤，離合器還包含有一個(gè)外殼、釋放桿、釋放軛、壓力彈簧和一個(gè)控制連接。 液壓制動(dòng)離合器分離裝置由一個(gè)踏板、分離彈簧、主氣缸、氣力調(diào)壓器、管道、軟管、分離叉的桿組成。一個(gè)德國(guó)的汽車制造者設(shè)計(jì)了一個(gè)自動(dòng)的離合器系統(tǒng)叫做Hydrak，它由一個(gè)液力飛輪連接著一個(gè)干燥的轉(zhuǎn)盤。叫做半離心式離合器，壓盤有六個(gè)圓柱滾輪，它在離心力的作用下向外運(yùn)動(dòng)，直至觸到外殼。同樣需要一個(gè)速比以避免高速公路上過(guò)高的發(fā)動(dòng)機(jī)轉(zhuǎn)速/每分鐘。如果在主動(dòng)齒輪和從動(dòng)齒輪之間引進(jìn)中間齒輪，從動(dòng)齒輪的轉(zhuǎn)動(dòng)方向?qū)?huì)變化。輸出端的另一端在變速器機(jī)身的滾動(dòng)軸承中做旋轉(zhuǎn)運(yùn)動(dòng)。有兩個(gè)滑動(dòng)齒輪或同步嚙合套的叫做2范圍，三個(gè)齒輪的叫做3范圍