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中期檢查報(bào)告
題目 神野牌輕型載貨汽車變速器設(shè)計(jì)
院（系） 專業(yè) 班
學(xué)生姓名
學(xué) 號(hào)
指導(dǎo)教師
年 月 日
自 檢 報(bào) 告
(要點(diǎn):1.設(shè)計(jì)工作任務(wù)的進(jìn)展情況 2.未按計(jì)劃完成工作任務(wù)的原因 3.工作中所遇到的問(wèn)題 4.下一步工作打算)
一、設(shè)計(jì)工作任務(wù)的進(jìn)展情況
1）2月27日至3月 3 日：熟悉課題，收集和整理關(guān)于神野牌輕型載貨汽車變速器的相關(guān)資料。
2）3月 6 日至3月10日：提出研究方案，準(zhǔn)備開題。
3）3月13日至3月31日：設(shè)計(jì)計(jì)算，開題答辯，在實(shí)驗(yàn)室對(duì)變速器進(jìn)行拆裝，對(duì)變速器的結(jié)構(gòu)和裝配有了更加深刻的了解。
4）4月 3 日至4月14日：確定變速器各檔位的傳動(dòng)比。對(duì)各檔位齒輪的齒數(shù)進(jìn)行確定，設(shè)計(jì)計(jì)算并確定齒輪的各項(xiàng)參數(shù)，并對(duì)每一個(gè)齒輪的接觸應(yīng)力、彎曲應(yīng)力進(jìn)行校驗(yàn)。確定中間軸各齒輪處的直徑，對(duì)中間軸的剛度和強(qiáng)度進(jìn)行校驗(yàn)。
5）4月17日至5月 5 日：繪制二維裝配圖，進(jìn)行外文翻譯（2000單詞以上）。
二、未按計(jì)劃完成工作任務(wù)的原因
無(wú)
三、工作中所遇到的問(wèn)題
在進(jìn)行中間軸的設(shè)計(jì)過(guò)程中，發(fā)現(xiàn)自己掌握的不夠扎實(shí)，又重新學(xué)習(xí)了《機(jī)械設(shè)計(jì)》中有關(guān)軸設(shè)計(jì)的介紹，必須滿足軸的工藝性合理，同時(shí)又要保證與軸配合的齒輪的定位準(zhǔn)確。在進(jìn)行齒輪設(shè)計(jì)過(guò)程中，又查看了《機(jī)械原理》關(guān)于直齒輪和斜齒輪的介紹，對(duì)比了一下各自的優(yōu)缺點(diǎn)，然后進(jìn)行選擇和設(shè)計(jì)。
在進(jìn)行齒輪參數(shù)的確定時(shí)反復(fù)計(jì)算和校驗(yàn)了許多遍，軸的強(qiáng)度剛度校核時(shí)也出現(xiàn)了類似問(wèn)題，多次校驗(yàn)后才使之成功。專業(yè)課知識(shí)還不夠熟練，在計(jì)算過(guò)程中需要花大量的時(shí)間在加強(qiáng)專業(yè)課知識(shí)的學(xué)習(xí)上。
四、下一步工作打算
在前期工作完成的基礎(chǔ)上，今后的工作計(jì)劃如下：
1）5月 8 日至6月 2 日：繪制三維裝配圖。
2）6月 5 日至6月16日：繪制三維裝配圖。
3）6月19日至6月23日：撰寫設(shè)計(jì)計(jì)算說(shuō)明書。
4）6月26日至6月 30 日：準(zhǔn)備答辯。
學(xué)生簽字：
年 月 日
指導(dǎo)教師意見：
指導(dǎo)教師簽字：
年 月 日
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教研室主任簽字:
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2
Manual transmission
1.Introduction
The purpose of the transmission in an automobile is to transfer the power created by the engine to the wheels via a drive shaft or half-axles. Differing gears in the transmission allow for different levels of torque to be applied to the wheels depending on the speed at which the vehicle is traveling. In order to change the level of torque the gears in the transmission need to be shifted either manually or automatically. In the beginning all transmissions were manual.French inventors Louis-Rene Panhard and Emile Levassor are credited with the development of the first modern manual transmission. They demonstrated their three-speed transmission in 1894 and the basic design is still the starting point for most contemporary manual transmissions.Panhard and Levassor used a chain drive on their original transmission. In 1898 auto maker Louis Renault used their basic design, but substituted a drive shaft for the drive chain and added a differential axle for the rear wheels to improve performance of the manual transmission.By the beginning of the 20th century most cars manufactured in the United States featured a non-synchronized manual transmission based on the Panhard/Levassor/Renault design. The next major innovation occurred in 1928 when Cadillac introduced the synchronized manual transmission, which significantly reduced gear grinding and made shifting smoother and easier.Manual transmissions were the standard on most vehicle for the first half of the 20th century, but automatic transmissions were being developed as far back as 1904. General Motors introduced the clutchless automatic transmission under the moniker, Hydra-Matic, in 1938, but the first true fully automatic transmission didn't appear until 1948 with the Buick Dynaflow transmission.
2.Background
Americans tend to prefer automatic transmission in their vehicles while Western Europe is--and is expected to remain--the largest market for manual transmissions through 2014. Eastern Europe and Asia are also large markets for manual transmission although Japan appears to be embracing more automatic transmissions. In the United States, more manual transmissions are found in the Northern states than in the Southern states. It is surmised that manual transmissions give better control on icy roads and are thus more useful in the North where the winters are more harsh.
Sports cars are often equipped with manual transmissions because they offer more direct driver involvement and better performance, though this is changing as many automakers move to faster dual-clutch transmissions, which are generally shifted with paddles located behind the steering wheel. For example, the 991 Porsche 911 GT3 uses Porsche's PDK. Off-road vehicles and trucks often feature manual transmissions because they allow direct gear selection and are often more rugged than their automatic counterparts.
Conversely, manual transmissions are no longer popular in many classes of cars sold in North America, Australia and some parts of Asia, although they remain dominant in Europe, Asia, Africa and Latin America. Nearly all cars are available with an automatic transmission option, and family cars and large trucks sold in the US are predominantly fitted with automatics, however in some cases if a buyer wishes he/she can have the car fitted with a manual transmission at the factory. In Europe most cars are sold with manual transmissions. Most luxury cars are only available with an automatic transmission. In most cases where both transmissions are available for a given car, automatics are an at cost option, but in some cases the reverse is true. Some cars, such as rental cars and taxis, are nearly universally equipped with automatic transmissions in countries such as the US, but the opposite is true in Europe. As of 2008, 75.2% of vehicles made in Western Europe were equipped with manual transmission, versus 16.1% with automatic and 8.7% with other.
Some trucks have transmissions that look and behave like ordinary car transmissions—these transmissions are used on lighter trucks, typically have up to 6 gears, and usually have synchromesh.
3. Composition for Manual Transmission.
Manual transmissions often feature a driver-operated clutch and a movable gear stick. Most automobile manual transmissions allow the driver to select any forward gear ratio ("gear") at any time, but some, such as those commonly mounted on motorcycles and some types of racing cars, only allow the driver to select the next-higher or next-lower gear. This type of transmission is sometimes called a sequential manual transmission.
In a manual transmission, the flywheel is attached to the engine's crankshaft and spins along with it. The clutch disk is in between the pressure plate and the flywheel, and is held against the flywheel under pressure from the pressure plate. When the engine is running and the clutch is engaged (i.e., clutch pedal up), the flywheel spins the clutch plate and hence the transmission. As the clutch pedal is depressed, the throw out bearing is activated, which causes the pressure plate to stop applying pressure to the clutch disk. This makes the clutch plate stop receiving power from the engine, so that the gear can be shifted without damaging the transmission. When the clutch pedal is released, the throw out bearing is deactivated, and the clutch disk is again held against the flywheel, allowing it to start receiving power from the engine.Manual transmissions are characterized by gear ratios that are selectable by locking selected gear pairs to the output shaft inside the transmission.
Contemporary automobile manual transmissions typically use four to six forward gear ratios and one reverse gear, although consumer automobile manual transmissions have been built with as few as two and as many as seven gears. Transmissions for heavy trucks and other heavy equipment usually have 8 to 25 gears so the transmission can offer both a wide range of gears and close gear ratios to keep the engine running in the power band. Operating aforementioned transmissions often use the same pattern of shifter movement with a single or multiple switches to engage the next sequence of gear selection.
3.1 Transmission shaft
Like other transmissions, a manual transmission has several shafts with various gears and other components attached to them. Typically, a rear-wheel-drive transmission has three shafts: an input shaft, a countershaft and an output shaft. The countershaft is sometimes called a layshaft.In many transmissions the input and output components of the mainshaft can be locked together to create a 1:1 gear ratio, causing the power flow to bypass the countershaft. The mainshaft then behaves like a single, solid shaft: a situation referred to as direct drive.Even in transmissions that do not feature direct drive, it's an advantage for the input and output to lie along the same line, because this reduces the amount of torsion that the transmission case has to bear.Under one possible design, the transmission's input shaft has just one pinion gear, which drives the countershaft. Along the countershaft are mounted gears of various sizes, which rotate when the input shaft rotates. These gears correspond to the forward speeds and reverse. Each of the forward gears on the countershaft is permanently meshed with a corresponding gear on the output shaft. However, these driven gears are not rigidly attached to the output shaft: although the shaft runs through them, they spin independently of it, which is made possible by bearings in their hubs.
3.2 Synchromesh
Most modern manual-transmission vehicles are fitted with a synchronized gear box. Transmission gears are always in mesh and rotating, but gears on one shaft can freely rotate or be locked to the shaft. The synchronizer has to overcome the momentum of the entire input shaft and clutch disk when it is changing shaft rpm to match the new gear ratio. It can be abused by exposure to the momentum and power of the engine, which is what happens when attempts are made to select a gear without fully disengaging the clutch. This causes extra wear on the rings and sleeves, reducing their service life. When an experimenting driver tries to "match the revs" on a synchronized transmission and force it into gear without using the clutch, the synchronizer will make up for any discrepancy in RPM. The success in engaging the gear without clutching can deceive the driver into thinking that the RPM of the layshaft and transmission were actually exactly matched. Nevertheless, approximate rev. matching with clutching can decrease the difference in rotational speed between the layshaft and transmission gear shaft, therefore decreasing synchro wear.
In a synchromesh gearbox, to correctly match the speed of the gear to that of the shaft as the gear is engaged the collar initially applies a force to a cone-shaped brass clutch attached to the gear, which brings the speeds to match prior to the collar locking into place. The collar is prevented from bridging the locking rings when the speeds are mismatched by synchro rings (also called blocker rings or baulk rings, the latter being spelled balk in the U.S.). The synchro ring rotates slightly due to the frictional torque from the cone clutch. In this position, the dog clutch is prevented from engaging. The brass clutch ring gradually causes parts to spin at the same speed. When they do spin the same speed, there is no more torque from the cone clutch and the dog clutch is allowed to fall into engagement. In a modern gearbox, the action of all of these components is so smooth and fast it is hardly noticed.
3.3 Reverse
Reverse gear is usually not synchromesh, as there is only one reverse gear in the normal automotive transmission and changing gears into reverse while moving is not required—and often highly undesirable, particularly at high forward speed.
3.4 Clutch
Among many different types of clutches, a dog clutch provides non-slip coupling of two rotating members. It is not at all suited to intentional slipping, in contrast with the foot-operated friction clutch of a manual-transmission car.
The gear selector does not engage or disengage the actual gear teeth which are permanently meshed. Rather, the action of the gear selector is to lock one of the freely spinning gears to the shaft that runs through its hub. The shaft then spins together with that gear. The output shaft's speed relative to the countershaft is determined by the ratio of the two gears: the one permanently attached to the countershaft, and that gear's mate which is now locked to the output shaft.
Locking the output shaft with a gear is achieved by means of a dog clutch selector. The dog clutch is a sliding selector mechanism which is splined to the output shaft, meaning that its hub has teeth that fit into slots (splines) on the shaft, forcing that shaft to rotate with it. However, the splines allow the selector to move back and forth on the shaft, which happens when it is pushed by a selector fork that is linked to the gear lever. The fork does not rotate, so it is attached to a collar bearing on the selector. The selector is typically symmetric: it slides between two gears and has a synchromesh and teeth on each side in order to lock either gear to the shaft.
4.Fuel Economy
The manual transmission couples the engine to the transmission with a rigid clutch instead of the torque converter on an automatic transmission or the v-belt of a continuously variable transmission, which slip by nature. Manual transmissions also lack the parasitic power consumption of the automatic transmission's hydraulic pump. Because of this, manual transmissions generally offer better fuel economy than automatic or continuously variable transmissions; however the disparity has been somewhat offset with the introduction of locking torque converters on automatic transmissions. Increased fuel economy with a properly operated manual transmission vehicle versus an equivalent automatic transmission vehicle can range from 5% to about 15% depending on driving conditions and style of driving. The lack of control over downshifting under load in an automatic transmission, coupled with a typical vehicle engine's greater efficiency under higher load, can enable additional fuel gains from a manual transmission by allowing the operator to keep the engine performing under a more efficient load/RPM combination. This is especially true as between manual and automatic versions of older models, as more recent advances including variable valve timing reduce the efficiency disadvantages of automatic transmissions by allowing better performance over a broader RPM range. In recognition of this, many current models (2010 and on) come with manual modes, or overrides on automatic models, although the degree of control varies greatly by the manufacturer. Also, manual transmissions do not require active cooling and because they are, mechanically, much simpler than automatic transmissions, they generally weigh less than comparable automatics, which can improve economy in stop-and-go traffic.[16] However this gap in economy is being rapidly closed, and many mid to higher end model automatic cars now get better economy than their standard spec counterparts[citation needed]. This is in part due to the increasing impact of computers co-ordinating multiple systems, particularly in hybrid models in which the engine and drive motors must be managed.
手動(dòng)變速器
1.說(shuō)明
汽車傳動(dòng)的目的是通過(guò)驅(qū)動(dòng)軸或半軸將發(fā)動(dòng)機(jī)驅(qū)動(dòng)車輪的動(dòng)力傳遞給車輪。在變速器中不同的齒輪允許不同程度的扭矩被施加到車輪上，這取決于車輛行駛的速度。為了改變變速器中的齒輪的轉(zhuǎn)矩的水平，需要手動(dòng)或自動(dòng)移動(dòng)。在開始時(shí)，所有的傳輸都是手動(dòng)的。法國(guó)發(fā)明家路易斯雷內(nèi)潘哈德和埃米爾勒瓦索被認(rèn)為是第一個(gè)促進(jìn)現(xiàn)代手動(dòng)變速器的發(fā)展的人。他們?cè)?894年展示了他們的三擋變速器，其基本的設(shè)計(jì)仍然是現(xiàn)代的手動(dòng)變速器的起點(diǎn)。潘哈德和勒瓦索在原來(lái)傳輸?shù)幕A(chǔ)上改用鏈傳動(dòng)。1898年，汽車制造商路易斯雷諾使用他們的基本設(shè)計(jì)，但是使用了驅(qū)動(dòng)軸取代了驅(qū)動(dòng)鏈，并在后橋增加了一個(gè)差速器，以提高手動(dòng)變速器性能。在第二十世紀(jì)初美國(guó)制造的大多數(shù)汽車采用了美國(guó)特色的非同步手動(dòng)變速器都是基于潘哈德/勒瓦索/雷諾設(shè)計(jì)。下一個(gè)重大創(chuàng)新發(fā)生在1928年，當(dāng)凱迪拉克推出同步手動(dòng)變速器，這大大減少齒輪磨削，使換檔更順暢，更容易。在二十世紀(jì)上半年手動(dòng)變速器的標(biāo)準(zhǔn)被大多數(shù)車輛采用，但自動(dòng)變速器的開發(fā)可追溯到1904年。在1938年，通用汽車為生產(chǎn)的離合器自動(dòng)變速器取名為Hydra-Matic，但第一個(gè)真正的全自動(dòng)變速器的出現(xiàn)直到1948年的別克流體動(dòng)力傳輸?shù)某霈F(xiàn)。
2.背景
2014年調(diào)查顯示，美國(guó)人更傾向于在他們的車上安裝自動(dòng)變速器，而西歐預(yù)計(jì)保持最大的手動(dòng)變速器市場(chǎng)。東歐和亞洲也有大量的手動(dòng)變速器市場(chǎng)，日本似乎擁有更多的自動(dòng)變速器。在美國(guó)，手動(dòng)變速器在北方各州比在南部各州更廣為使用。據(jù)推測(cè)，手動(dòng)變速器可以更好地控制在結(jié)冰的路面上的行駛，從而更有效的適應(yīng)更惡劣的北方冬天。
跑車往往配備手動(dòng)變速箱，因?yàn)樗麄兲峁└嗟闹苯域?qū)動(dòng)的參與和更好的性能，盡管這是許多汽車制造商將更快的雙離合器變速箱的變化，它通常是位 于方向盤槳移。例如，991保時(shí)捷911 GT3使用保時(shí)捷的PDK。越野車和卡車經(jīng)常采用手動(dòng)變速器，因?yàn)樗鼈冊(cè)试S直接齒輪的選擇，而且往往比他們的自動(dòng)變速器更堅(jiān)固耐用。
相反，在北美 國(guó)、澳大利亞以及亞洲的一些地區(qū)，手動(dòng)變速器不再流行，雖然它們?cè)跉W洲、亞洲、非洲和拉丁美洲都是占主導(dǎo)地位的美國(guó)。幾乎所有的汽車都可以與自動(dòng)變速器的 選擇，家庭轎車和大卡車在美國(guó)銷售的主要配備自動(dòng)化，但是在某些情況下，如果買方希望他/她能把車裝在工廠的手動(dòng)變速器。在歐洲，大多數(shù)汽車都是用手動(dòng)變 速器出售的。大多數(shù)豪華車只能用一種自動(dòng)變速器。在大多數(shù)情況下，傳輸，可用于一個(gè)給定的汽車，自動(dòng)變速器是一個(gè)在成本的選擇，但在某些情況下是正確的。 一些汽車，如出租汽車和出租車，幾乎全世界都配備了自動(dòng)變速器，如美國(guó)，但相反的是真實(shí)的，在歐洲，2008，75.2%的車輛在西歐，配備手動(dòng)變速器， 與16.1%與自動(dòng)和其他8.7%。一些卡車變速器的外觀和行為像普通汽車變速器這些傳輸用于輕卡車，通常有6個(gè)齒輪，通常有同步。
3.變速器組成.
手動(dòng)變速器通常有一個(gè)驅(qū)動(dòng)操縱離合器和一個(gè)可移動(dòng)的撥叉。大多數(shù)汽車的手動(dòng)變速器允許司機(jī)在任何時(shí)候選擇任何前進(jìn)檔位，但有些，如一般安裝在摩托車和某些類型的賽車，只允許司機(jī)選擇下一個(gè)或下一個(gè)較低的檔位。這種類型的傳輸有時(shí)被稱為順序手動(dòng)變速器。在一個(gè)手動(dòng)變速器，飛輪是連接到發(fā)動(dòng)機(jī)的曲軸和旋轉(zhuǎn)一起。離合器盤在壓力板與飛輪之間，并在壓力下與飛輪保持在一起。當(dāng)發(fā)動(dòng)機(jī)運(yùn)轉(zhuǎn)時(shí)，離合器接合，飛輪轉(zhuǎn)動(dòng)離合器盤。由于離合器踏板是凹陷的，這會(huì)導(dǎo)致壓力板停止向離合器盤施加壓力。這使得離合器停止接收發(fā)動(dòng)機(jī)的功率，使變速器可以換擋，而不損壞傳輸。當(dāng)離合器踏板被釋放時(shí)，分離軸承被停用，離合器盤再次被與飛輪接合，允許它開始從發(fā)動(dòng)機(jī)接收功率。手動(dòng)變速器的特點(diǎn)是通過(guò)鎖定選定的齒輪副的傳動(dòng)比，從而決定傳輸?shù)妮敵鲚S的齒輪比。
現(xiàn)代汽車的手動(dòng)變速器通常采用（4+1）檔，或者（6+1）檔。雖然消費(fèi)者的汽車手動(dòng)變速器已經(jīng)建立了七個(gè)檔位。而且重型卡車和其他重型設(shè)備的變速器通常有8至25個(gè)檔位，因此變速器可以同時(shí)提供一個(gè)較大范圍的齒輪比，以保持發(fā)動(dòng)機(jī)在最佳功率運(yùn)行。操作上述變速器經(jīng)常使用相同的模式。即選用一個(gè)或者多個(gè)操縱桿來(lái)進(jìn)行檔位的選擇。
3.1 變速器軸
與其它變速器一樣，手動(dòng)變速器軸上包含不同的齒輪和其它連接部件。通常情況下，后輪驅(qū)動(dòng)的變速器有三個(gè)軸：輸入軸、中間軸和輸出軸。副軸有時(shí)被稱為中間軸。許多變速器的輸入和輸出的主軸組件可以被鎖在一起，創(chuàng)建一個(gè)1:1的傳動(dòng)比，使功率流繞過(guò)副軸。主軸然后像一個(gè)單一的實(shí)心軸：這種情況稱為直接驅(qū)動(dòng)。直接驅(qū)動(dòng)時(shí)輸入和輸出沿一條直線是一個(gè)很大的優(yōu)勢(shì)，因?yàn)檫@降低了扭矩，變速箱承受量。一個(gè)可能的設(shè)計(jì)，變速器的輸入軸只有一個(gè)小齒輪，從而帶動(dòng)副軸。沿中間軸安裝不同尺寸的齒輪，輸入軸轉(zhuǎn)動(dòng)時(shí)。這些齒輪對(duì)應(yīng)的正向速度和反向。每一個(gè)前進(jìn)檔中間軸上永久嚙合輸出軸上的相應(yīng)齒輪。然而這些從動(dòng)齒輪不剛性連接到輸出軸：雖然軸運(yùn)行通過(guò)他們，他們獨(dú)立地旋轉(zhuǎn)，這時(shí)由軸承在高速旋轉(zhuǎn)。
3.2 變速器同步器
大多數(shù)現(xiàn)代的手動(dòng)變速器都配有一個(gè)同步齒輪箱。變速器齒輪總是在嚙合和旋轉(zhuǎn)，但在一個(gè)軸上的齒輪可以自由旋轉(zhuǎn)或被鎖定到軸上。同步器克服了整個(gè)輸入軸和離合器盤在改變軸的轉(zhuǎn)速來(lái)匹配新的齒輪比。它可以通過(guò)暴露于發(fā)動(dòng)機(jī)的動(dòng)力選擇一個(gè)齒輪來(lái)?yè)Q擋，但沒(méi)有完全分離離合器。這會(huì)導(dǎo)致環(huán)和套筒額外的磨損，減少他們的使用壽命。當(dāng)司機(jī)試圖嘗試換擋，匹配的轉(zhuǎn)速在同步傳輸和力成齒輪不使用離合器，同步將彌補(bǔ)換擋時(shí)轉(zhuǎn)速的差異。不過(guò)近似配合，能降低中間軸和傳動(dòng)齒輪軸之間的轉(zhuǎn)速差，因此降低同步磨損。
在一個(gè)同步器變速箱，正確匹配的齒輪轉(zhuǎn)速，軸的齒輪嚙合齒圈最初施加力到錐形黃銅離合器連接到齒輪，它匹配的齒圈鎖定到之前帶來(lái)的速度。衣領(lǐng)是防止連接鎖定環(huán)時(shí)速度不匹配同步環(huán)。同步環(huán)輕微旋轉(zhuǎn)，由于摩擦扭矩從錐形離合器到這個(gè)位置，離合器被阻止接合。黃銅離合器環(huán)逐漸使零件以相同的速度旋轉(zhuǎn)。當(dāng)它們旋轉(zhuǎn)相同的速度，有沒(méi)有更多的扭矩從錐形離合器和離合器被允許進(jìn)入接觸。在現(xiàn)代的齒輪箱，所有這些組件的作用是如此的平穩(wěn)和快速，幾乎沒(méi)有注意到。
3.3 倒檔
倒檔齒輪通常是不同步的，因?yàn)槠胀ǖ钠囎兯倨髦挥幸粋€(gè)倒檔，并且汽車正常行駛時(shí)不需要經(jīng)常換到倒檔，尤其是在高速行駛時(shí)。
3.4 離合器
在眾多不同類型的離合器中，齒式離合器是提供非滑動(dòng)耦合的雙旋轉(zhuǎn)的成員。它不限滑的，相反，干式摩擦離合器的手動(dòng)變速器是限滑的。
同步器不接合或脫離永久嚙合齒輪齒。同步器的作用是把一個(gè)自由旋轉(zhuǎn)的齒輪鎖定在軸上，通過(guò)它的中心，然后軸與齒輪一起旋轉(zhuǎn)。輸出軸的速度相對(duì)于副軸是由兩齒輪的比值決定：一個(gè)永久連接到中間軸，且相嚙合的齒輪現(xiàn)在鎖定到輸出軸。鎖定輸出軸與齒輪是通過(guò)一個(gè)離合器實(shí)現(xiàn)。離合器的機(jī)理是通過(guò)花鍵與輸出軸實(shí)現(xiàn)，這意味著它的樞紐已融入槽齒（花鍵）在軸上，通過(guò)軸轉(zhuǎn)動(dòng)它。然而，花鍵允許花鍵轂在軸上來(lái)回移動(dòng)，當(dāng)它被一個(gè)與齒輪桿相連的撥叉推的時(shí)候，撥叉不旋轉(zhuǎn)，所以它是連接到一個(gè)衣領(lǐng)軸承上的選擇器。選擇器器通常是對(duì)稱的：它位于兩檔齒輪之間并有一個(gè)同步器把每側(cè)齒輪鎖到齒輪軸。
4.燃油經(jīng)濟(jì)性
手動(dòng)變速器與離合器剛性連接，而不是像自動(dòng)變速器、無(wú)級(jí)變速器的帶液力變矩器傳輸引擎。手動(dòng)變速器也缺乏自動(dòng)變速器的液壓泵的保存功率消耗功能。因此，手動(dòng)變速器一般提供比自動(dòng)或無(wú)級(jí)變速器更好的燃油經(jīng)濟(jì)性；然而，差距已經(jīng)有所抵消，引進(jìn)的自動(dòng)變速器鎖定扭矩轉(zhuǎn)換器。增加燃油經(jīng)濟(jì)性與適當(dāng)?shù)牟倏v技巧，手動(dòng)變速器汽車等效自動(dòng)變速器的車輛，根據(jù)駕駛條件和駕駛風(fēng)格可以在5%到15%的范圍。在低檔載荷下自動(dòng)變速器控制的不足，再加上一個(gè)典型的汽車發(fā)動(dòng)機(jī)的效率更高的負(fù)載，可以使手動(dòng)變速器從額外的收益燃料允許經(jīng)營(yíng)者保持引擎執(zhí)行U在一個(gè)更有效的負(fù)荷/轉(zhuǎn)速組合。這是特別真實(shí)的手動(dòng)和自動(dòng)版本的舊機(jī)型，隨著越來(lái)越多的最新進(jìn)展，包括可變氣門正時(shí)減少自動(dòng)變速器的效率的缺點(diǎn)，允許更好的性能在更廣泛的轉(zhuǎn)速范圍。認(rèn)識(shí)到這一點(diǎn)，許多現(xiàn)有的模型（2010）來(lái)自手動(dòng)模式、自動(dòng)模式或重寫，雖然控制程度差別很大。另外，手動(dòng)變速器不需要主動(dòng)冷卻，因?yàn)樗麄兪菣C(jī)械，比自動(dòng)變速器簡(jiǎn)單得多，一般體重小于可比的自動(dòng)化，從而提高經(jīng)濟(jì)在走走停停的交通。但是這種經(jīng)濟(jì)差距正在迅速關(guān)閉，很多中高端的模型自動(dòng)車現(xiàn)在得到比標(biāo)準(zhǔn)規(guī)格的同行更好的經(jīng)濟(jì)。這部分是由于計(jì)算機(jī)協(xié)調(diào)多個(gè)系統(tǒng)的影響越來(lái)越大，特別是在混合動(dòng)力車型的發(fā)動(dòng)機(jī)和驅(qū)動(dòng)電機(jī)必須管理。