The modern automatic transmission is by far , the most complicated mechanical component in today’s automobile . It is a type of transmission that sifts itself . A fluid coupling or torque converter is used instead of a manually operated clutch to connect the transmission to the engine .
There are two basic types of automatic transmission based on whether the vehicle is rear wheel drive or front wheel drive . On a rear wheel drive car , the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position . A drive shaft connects the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels . Power flow on this system is simple and straight forward going from the engine , through the torque converter , then trough the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear transmission .
對(duì)于現(xiàn)代的汽車，自動(dòng)變速器是一個(gè)復(fù)雜的組件，這種傳遞動(dòng)力的方式，是液力變矩期充當(dāng)離合器來(lái)連接發(fā)動(dòng)機(jī)和變速器。
兩個(gè)基本類型的自動(dòng)變速器基于該車輛是否是前驅(qū)動(dòng)或后驅(qū)動(dòng)。對(duì)發(fā)動(dòng)機(jī)前置后驅(qū)動(dòng)的汽車，變速器通常安裝在發(fā)動(dòng)機(jī)后底盤中心與油門配合。變速器輸出軸連接到后橋，把發(fā)動(dòng)機(jī)的動(dòng)力傳遞到后輪，動(dòng)力傳輸系統(tǒng)是直線的，從發(fā)動(dòng)機(jī)，通過(guò)液力變矩器、變速器、傳動(dòng)軸、最后直接到到達(dá)車輪。
對(duì)于發(fā)動(dòng)機(jī)前置前輪驅(qū)動(dòng)的汽車，變速器通常和差速器裝在一起。對(duì)于前驅(qū)動(dòng)的汽車，變速器安裝在發(fā)動(dòng)機(jī)一側(cè)，前車軸直接連接到差速器上，把動(dòng)力傳遞給前輪。在這個(gè)布置中，動(dòng)力來(lái)自于發(fā)動(dòng)機(jī)，通過(guò)液力變矩器、變速器輸出的動(dòng)力通過(guò)了一個(gè)180度大轉(zhuǎn)彎，經(jīng)過(guò)變速器沿發(fā)動(dòng)機(jī)側(cè)邊通過(guò)傳動(dòng)軸輸出到前輪。
還有其它的一些布置，發(fā)動(dòng)機(jī)前置前驅(qū)動(dòng)，發(fā)動(dòng)機(jī)橫向布置，裝設(shè)一個(gè)分動(dòng)器可以實(shí)現(xiàn)四輪驅(qū)動(dòng)。但這種形式目前是最常用的：發(fā)動(dòng)機(jī)中置后驅(qū)動(dòng)，可以使重量均勻的分布在前、后輪之間，改善了操作性能；發(fā)動(dòng)機(jī)后置后驅(qū)動(dòng)，發(fā)動(dòng)機(jī)、變速器、驅(qū)動(dòng)輪都在后方，這