CA6440輕型客車變速器設計【含5張CAD圖紙】

喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預覽哦。下載后都有，請放心下載，文件全都包含在內，有疑問咨詢QQ:1064457796 附錄 專業(yè)外文及翻譯Automatic TransmissionManual transmissions often feature a driver-operated clutch and a movable gear selector. 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. Sequential transmissions are commonly used in auto racing for their ability to make quick shifts.Manual transmissions are characterized by gear ratios that are selectable by locking selected gear pairs to the output shaft inside the transmission. Conversely, most automatic transmissions feature epicyclic (planetary) gearing controlled by brake bands and/or clutch packs to select gear ratio. Automatic transmissions that allow the driver to manually select the current gear are called Manumatics. A manual-style transmission operated by computer is often called an automated transmission rather than an automatic.Contemporary automobile manual transmissions typically use four to six forward gears and one reverse gear, although automobile manual transmissions have been built with as few as two and as many as eight gears. Transmission for heavy trucks and other heavy equipment usually have at least 9 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. Some heavy vehicle transmissions have dozens of gears, but many are duplicates, introduced as an accident of combining gear sets, or introduced to simplify shifting. Some manuals are referred to by the number of forward gears they offer (e.g., 5-speed) as a way of distinguishing between automatic or other available manual transmissions. Similarly, a 5-speed automatic transmission is referred to as a 5-speed automatic.Unsynchronized transmissionThe earliest form of a manual transmission is thought to have been invented by Louis-Ren Panhard and Emile Levassor in the late 19th century. This type of transmission offered multiple gear ratios and, in most cases, reverse. The gears were typically engaged by sliding them on their shafts hence the term shifting gears, which required a lot of careful timing and throttle manipulation when shifting, so that the gears would be spinning at roughly the same speed when engaged; otherwise, the teeth would refuse to mesh. These transmissions are called sliding mesh transmissions and sometimes called a crash box. Most newer transmissions instead have all gears mesh at all times but allow some gears to rotate freely on their shafts; gears are engaged using sliding-collar dog clutches; these are referred to as constant-mesh transmissions.In both types, a particular gear combination can only be engaged when the two parts to engage (either gears or dog clutches) are at the same speed. To shift to a higher gear, the transmission is put in neutral and the engine allowed to slow down until the transmission parts for the next gear are at a proper speed to engage. The vehicle also slows while in neutral and that slows other transmission parts, so the time in neutral depends on the grade, wind, and other such factors. To shift to a lower gear, the transmission is put in neutral and the throttle is used to speed up the engine and thus the relevant transmission parts, to match speeds for engaging the next lower gear. For both upshifts and downshifts, the clutch is released (engaged) while in neutral. Some drivers use the clutch only for starting from a stop, and shifts are done without the clutch. Other drivers will depress (disengage) the clutch, shift to neutral, then engage the clutch momentarily to force transmission parts to match the engine speed, then depress the clutch again to shift to the next gear, a process called double clutching. Double clutching is easier to get smooth, as speeds that are close but not quite matched need to speed up or slow down only transmission parts, whereas with the clutch engaged to the engine, mismatched speeds are fighting the rotational inertia and power of the engine.Even though automobile and light truck transmissions are now almost universally synchronised, transmissions for heavy trucks and machinery, motorcycles, and for dedicated racing are usually not. Non-synchronized transmission designs are used for several reasons. The friction material, such as brass, in synchronizers is more prone to wear and breakage than gears, which are forged steel, and the simplicity of the mechanism improves reliability and reduces cost. In addition, the process of shifting a synchromesh transmission is slower than that of shifting a non-synchromesh transmission. For racing of production-based transmissions, sometimes half the teeth (or dogs) on the synchros are removed to speed the shifting process, at the expense of greater wear.Heavy duty trucks use unsynchronized transmissions in the interest of saving weight.citation needed Military edition trucks, which do not have to obey weight laws, usually have synchronized transmissions, though this is also contingent upon the need for non trained personnel to be able to operate them in emergencies. Highway use heavy-duty trucks in the United States are limited to 80,000 pounds GVWR, and the lighter the curb weight for the truck, the more cargo can be carried; with a synchronizer adding weight to a truck that could otherwise be used to carry cargo, most drivers are simply taught how to double clutch, initially, and then most eventually gravitate to shifting without the clutch.citation needed In the United States, traffic safety rules refer to non-synchronous transmissions in classes of larger commercial motor vehicles. In Europe heavy duty trucks use synchronized gearboxes as standard.Similarly, most modern motorcycles use unsynchronized transmissions as synchronizers are generally not necessary or desirable. Their low gear inertias and higher strengths mean that forcing the gears to alter speed is not damaging, and the pedal operated selector on modern motorcycles is not conducive to having the long shift time of a synchronized gearbox. Because of this, it is necessary to synchronize gear speeds by blipping the throttle when shifting into a lower gear on a motorcycle.Synchronised transmissionTop and side view of a typical manual transmission, in this case a Ford Toploader, used in cars with external floor shifters.Most modern cars are fitted with a synchronised 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 locking mechanism for a gear consists of a collar (or dog collar) on the shaft which is able to slide sideways so that teeth (or dogs) on its inner surface bridge two circular rings with teeth on their outer circumference: one attached to the gear, one to the shaft. When the rings are bridged by the collar, that particular gear is rotationally locked to the shaft and determines the output speed of the transmission. The gearshift lever manipulates the collars using a set of linkages, so arranged so that one collar may be permitted to lock only one gear at any one time; when shifting gears, the locking collar from one gear is disengaged before that of another engaged. One collar often serves for two gears; sliding in one direction selects one transmission speed, in the other direction selects another.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, with the latter being spelt 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 in to engagement. In a modern gearbox, the action of all of these components is so smooth and fast it is hardly noticed.ShaftsLike 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 a rear-wheel-drive transmission, the input and output shaft lie along the same line, and may in fact be combined into a single shaft within the transmission. This single shaft is called a mainshaft. The input and output ends of this combined shaft rotate independently, at different speeds, which is possible because one piece slides into a hollow bore in the other piece, where it is supported by a bearing. Sometimes the term mainshaft refers to just the input shaft or just the output shaft, rather than the entire assembly.In some transmissions, its possible for the input and output components of the mainshaft to 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, its 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 transmissions 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. Reverse is typically implemented differently, see the section on Reverse.Most front-wheel-drive transmissions for transverse engine mounting are designed differently. For one thing, they have an integral final drive and differential. For another, they usually have only two shafts; input and countershaft, sometimes called input and output. The input shaft runs the whole length of the gearbox, and there is no separate input pinion. At the end of the second (counter/output) shaft is a pinion gear that mates with the ring gear on the differential.Front-wheel and rear-wheel-drive transmissions operate similarly. When the transmission is in neutral, and the clutch is disengaged, the input shaft, clutch disk and countershaft can continue to rotate under their own inertia. In this state, the engine, the input shaft and clutch, and the output shaft all rotate independently.SynchromeshIf the teeth, the so-called dog teeth, make contact with the gear, but the two parts are spinning at different speeds, the teeth will fail to engage and a loud grinding sound will be heard as they clatter together. For this reason, a modern dog clutch in an automobile has a synchronizer mechanism or synchromesh, which consists of a cone clutch and blocking ring. Before the teeth can engage, the cone clutch engages first which brings the selector and gear to the same speed using friction. Moreover, until synchronization occurs, the teeth are prevented from making contact, because further motion of the selector is prevented by a blocker (or baulk) ring. When synchronization occurs, friction on the blocker ring is relieved and it twists slightly, bringing into alignment certain grooves and notches that allow further passage of the selector which brings the teeth together. Of course, the exact design of the synchronizer varies from manufacturer to manufacturer.The synchronizer has to change the momentum of the entire input shaft and clutch disk. Additionally, it can be abused by exposure to the momentum and power of the engine itself, 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 general delta between layshaft and transmission and decrease synchro wear.手動變速器手動變速箱通常設有一個司機操縱離合器和一個可移動的齒輪選擇器。大多數(shù)汽車手動變速器允許在任何的時間選擇任何前進傳動比齒輪，但是一些裝在摩托車和某些類型的賽車上的手動變速器，只允許司機選擇下一個更高或下一個較低的傳動比齒輪。這種傳送方式有時也被稱為順序手動變速箱。順序傳輸，通常用于賽車上，使車有迅速轉變的能力。手動變速箱的特點是通過選擇內部齒輪比例鎖定輸出軸的傳動。相反，大多數(shù)自動變速器的行星齒輪傳動的特點是由剎車帶或離合器包選擇齒輪比。能讓駕駛者手動選擇當前擋位的自動變速箱，被稱為手自一體變速器。由計算機控制的變速器類型通常稱為電控自動變速器，而不是一般的自動變速箱。盡管現(xiàn)在汽車手動變速箱，有少達的兩個和多達8個齒輪，但現(xiàn)代汽車手動變速箱，通常使用4至6個前進檔和一個倒檔。重型卡車和其他重型設備的變速器通常有至少9個齒輪，這樣，傳動時可以同時提供一個廣泛和密切的齒輪傳動比，以保持發(fā)動機的功率頻帶上運行。一些重型汽車變速箱齒輪有幾十個，但很多是重復的，作為一個齒輪組相結合，以簡化結構。有些手冊所提到的數(shù)目，以前進檔為例（例如，5擋變速器）作為手動和自動變速器之間的一種可手動變速箱或其他的方式。同樣，一個5擋自動變速器是被稱為“5擋自動變速?！睙o同步換擋變速器最早形式的用手操作的變速變速器被認為是由圣路易斯的勒內潘哈德和埃米爾勒瓦索爾于19世紀發(fā)明。這種變速器提供多種傳動比，并在大多數(shù)情況下，能反向。齒輪是通過軸滑動來進行所謂“換擋”，這需要精心的操縱和油門，使齒輪將在大致相同的旋轉速度時進行換擋，否則，就不能掛上擋。這些變速器被稱為“滑移齒輪換擋”變速器。大多數(shù)較新的變速箱，并不是在任何時候都完全嚙合，但允許一些齒輪、齒輪軸他們自由的轉動；使用滑動齒輪換擋的齒式離合器，被稱為固定嚙合變速器。在這兩種類型，在同一速度下，一個特別的齒輪組合只能在兩個部分速度相同時接合。掛上一個更低的擋位上，先回到空擋，降速直到下兩齒輪在適當?shù)乃俣冗M行接合。該車輛在空檔時也會降低速度，并的降低各級傳動，因此在空檔的時間取決于等級、 風和其他等因素。轉移到較高擋的齒輪，先回到空擋，在空擋踩油門來加速引擎，從而使兩者速度能有相等時候。對于這兩個加減檔，離合器接合，在空擋。有些司機只習慣于從一開始就能接合離合器，離合器的接合變化卻不習慣做。其他司機會斷開離合器，轉到空擋在，然后進行短暫的分離，使傳動部件與發(fā)動機轉速匹配，然后再掛擋下一個齒輪，這個過程被稱為雙腳離合。雙腳離合是比較容易實現(xiàn)，因為速度是相當接近，但不匹配時需要加快或減慢傳動部件。而發(fā)動機，離合器的速度不匹配，損耗的是發(fā)動機的功率。盡管汽車和輕型卡車變速箱現(xiàn)在幾乎普遍同步，但在重型卡車和工程機械，摩托車以及專用賽車的變速器通常不同步。非同步器變速器的設計，通常有幾個方面。摩擦材料，如黃銅，在同步器上比齒輪更容易磨損，采用鍛鋼較簡單能提高可靠性和降低成本。此外，滑移同步器傳變速器換擋過程是一個較緩慢移動的非同步器變速箱。對于以賽車的變速器生產(chǎn)為基礎，有時一半的齒頂都被切削，更大的磨損加快換擋過程。重型貨車使用無同步的變速器以便減少傳動慣量。軍用汽車，不必須遵守規(guī)定的重量，通常有同步器，盡管這還取決于對非培訓的人員必須能夠在隊伍的緊急情況下操作好。在美國公路上重型卡車總質量限于80000英鎊，輕卡車重量小，可以載更多的貨物可以進行；大部分司機只是學習如何雙腳離合，最初，然后最終回歸到最沒有離合器轉移。在美國，交通安全規(guī)則是指在課堂上的無同步變速器的較大型的商業(yè)機動車輛。在歐洲，重型貨車使用同步變速箱作為標準。 同樣的，最現(xiàn)代化的摩托車一般沒有必要使用非同步傳輸?shù)耐狡鳎膊豢扇?。其低慣性和高強度齒輪意味著迫使齒輪改變速度時不會被破壞，踏板摩托車在現(xiàn)代經(jīng)營選擇，不利于有一個長的轉變時間來達到同步的變速箱。由于這一點，同步就必須在油門的關鍵位置成為一個較低的摩托車齒輪換檔速度。 同步變速器 大多數(shù)現(xiàn)代汽車裝有同步齒輪箱。傳動齒輪總是在嚙合旋轉，但齒輪可以在自由旋轉或被鎖定在軸上。對于一個齒輪鎖定機制由一個軸環(huán)或齒輪上的軸環(huán)，它能夠使側向滑動齒輪在其內表面的兩個圓環(huán)上的外周長鎖定：一個連接到齒輪，一個連接到軸。當鎖環(huán)與齒輪旋轉軸鎖定時，就能確定輸出的速度。換檔桿操縱的傳動機構能保證準確的在任一時刻鎖定只有一個齒輪，當“換擋”時，從一個齒輪鎖緊環(huán)脫離。一個鎖環(huán)常常是連接兩個齒輪，在一個方向滑動選擇一個傳動速度在另一個方向，選擇另一個。在同步器變速箱，正確匹配速度的齒輪軸，齒輪，是因為鎖環(huán)將能量動力傳過去的，一個錐形黃銅離合器齒輪是重點，這使能在速度相匹配到地方將它們鎖定。當鎖定速度不匹配時，通過同步環(huán)達到目的匹配。環(huán)的同步旋轉從錐形離合器的錐面上產(chǎn)生摩擦力矩。在這一點上，齒式換擋離合器是無法比擬的。黃銅離合器環(huán)逐漸使各部分以相同的速度旋轉。當他們以同樣的速度旋轉，沒有更多的錐形離合器扭矩，離合器和齒輪就會參與。在現(xiàn)代變速箱，所有這些組件的運動傳動是如此順利和迅速，是當時沒有想到的。倒檔，通常是不同步配合，因為是逆向而動的。軸像其他變速器一樣，手動變速器的齒輪和各種附加到他們上的軸。通常情況下，后輪驅動傳動有三個軸：輸入軸，一個中間軸和輸出軸。該中間軸有時被稱為副軸。在后輪驅動的變速器中，輸入和輸出軸沿同一路線布置，事實上可合并為一個單一的軸。這種單一軸稱為主軸。輸入軸和輸出軸兩端獨立旋轉，以不同的速度，這是可能的，因為輸出軸嵌入輸入軸的中空部。在某些變速器中，輸入軸和輸出軸組件被鎖定，共同創(chuàng)造一個1:1齒速比，使功率流繞過中間軸。該主軸像一個單一的，實心軸的整體，這種情況被稱為直接擋驅動。即使在變速功能下，不直接驅動，這個優(yōu)勢使輸入和輸出沿同一路線，因為這減少了扭矩的減少。下一個可能的設計，變速器的輸入軸只有一個小齒輪，它驅動中間軸。沿中間軸是安裝各種尺寸的齒輪，其中齒輪旋轉由輸入軸驅動。這些齒輪可以正向和反向旋轉。每個齒輪是永久的與輸出軸齒輪嚙合。但是，這些驅動齒輪是沒有硬性附加到輸出軸上，通過這些軸來旋轉，它獨立在軸上旋轉。大多數(shù)前輪驅動的橫置發(fā)動機變速器裝配設計不同。一方面，他們有一個很完整的最終動力輸出。另一方面，他們通常只有兩軸，輸入軸和輸出軸。輸入軸齒輪箱覆蓋整個長度，也沒有獨立的輸入小齒輪。前輪和后輪驅動變速箱的操作方式相似。當傳輸是中立的，是脫離離合器，輸入軸，離合器盤和副軸旋轉可以繼續(xù)根據(jù)自己的惰性。在這種狀態(tài)下，引擎，輸入軸和離合器，輸出軸都獨立地自轉。同步器所謂的爪型齒，是與齒輪接觸，但兩部分在不同的速度旋轉，爪齒將無法吸引被到磨削他們?；谶@個原因，在現(xiàn)代汽車離合器有爪型同步器同步機制，它包括一個錐形離合器和封鎖圈。從第一錐型離合器帶來齒輪使用相同的速度摩擦。此外，直到同步發(fā)生，使爪齒無法接觸。當同步發(fā)生時，在攔截器環(huán)摩擦稍有緩解，同時帶來一定的調整，使槽和缺口的選擇帶來進一步的爪齒一起嚙合。當然，準確的同步器設計各有不同生產(chǎn)廠家。同步器要改變整個輸入軸和離合器盤的動力傳輸。此外，它還可以通過接觸與發(fā)動機本身，這是什么時候發(fā)生的選一個沒有完全脫離離合器齒輪。這將導致環(huán)上的額外磨損，縮短其使用壽命。當驅動嘗試“匹配的轉速同步傳輸”，強迫不使用離合器齒輪，同步將彌補任何轉速差異。以為可以抓住的是，中間軸傳動轉速，實際上完全匹配的驅動齒輪是成功。盡管如此，近似轉速。匹配可以減少和中間軸之間的同步傳輸，減少磨損。