【導讀】汽車電控自動變速器的故障診斷與分析【畢業(yè)設(shè)計，論。11變速器的發(fā)展狀況2. 12研究目的及意義3. 23自動變速器的特點5. 3液壓控制部分7. 液力變矩器的作用和組成7. 液力變矩器的工作原理8. 34換擋信號系統(tǒng)11. 4機械裝置及電控裝置17. 41組合式行星齒輪機構(gòu)17. 43故障自診斷和失效保護26. 54自動變速器的檢驗30. 55典型案例分析35. 6常見故障與排除方法36. 62自動變速器油易變質(zhì)37. 障診斷技術(shù)故障診斷技術(shù)提高了汽車的安全性和穩(wěn)定性對于保護人生安全具有。闡述診斷分析中應(yīng)注意的問題最后對變速器使用過程中常見故障給予分析處理。作易使駕駛員疲勞影響行駛安全而不同的駕駛技術(shù)水平對車輛的燃料經(jīng)濟性動。級階段發(fā)展的重要標志目前我國自動變速器在轎車城市客車高級旅游客車軍用。的不斷完善自動變速器已被廣泛地應(yīng)用于轎車大客車重型自卸車越野車貨車與。偶合器四個擋位的行星變速器和自動換擋系統(tǒng)組成的。器投入批量20年英國法國意大利原聯(lián)邦德國瑞典日本等國都已成立了一批自動

　　

【正文】 nuously Variable Transmission CVT Continuously variable transmissions may be in the form of mechanically infinitely variable transmission hydraulic or electric transmissions The basic technical criteria for continuously variable transmissions are size weight transmissionratio range transfer efficiency noise emissions and installation possibilities With regard to these aspects mechanical continuously variable converters in the form of chain driven transmissions with steel chains have provided the best results so far The conversion rage extends to 6 the efficiency reaching approx 059 This type of transmission is particularly suitable for frontwheeldrive passenger cars where axially offset transmission arrangements are easy to acmodate If chaindriven transmissions are not designed with power split they additionally require a driveaway element and a device for reversing the direction of rotation Automatic Transmission AT An automatic transmission is a device that provides gear reduction with resulting multiplication of torque The gear ranges are automatically selected to provide the most efficient operation and the best torque output 1Parts of an Automatic Transmission Automatic transmissions have three basic systemsa torque converter a gear system and a hydraulic system These fit together in a unit that fastens directly behind the engine The front section of the transmission houses the torque converter The torque converter is like the clutch in a manual transmission It is the coupling between the engine and power train that transmits power to the drive wheels In a manual transmission the clutch is a mechanical coupling The engine and drive train are physically fastened together when a driver engages the clutch A torque converter however is a hydrodynamic coupling The parts do not connect mechanically Instead a hydrodynamic transmits the power The gear section is behind the torque converter This has gears that change the gear ratios for torque multiplication and gear reduction The gear section has a number of part called clutches and bands These engage and release parts to change the gear ratios The gear section also has the input shaft and the output shaft needed to transmit power to the drive wheels The hydraulic system is below the gear section It uses fluid pressure for automatic control The hydraulic system is the brain of the transmission This section must know when to change from one gear to another It must also provide the fluid pressure needed to apply or release the parts of the gear section so that the gears shift at the correct time The hydraulic section uses such information to make the proper shifts 2Plaary Gear The gear system changes the ratios in the automatic transmission However the gear system in an automatic transmission is different from the gear system in a manual transmission Instead of a countershaft and gears an automatic transmission has a plaary gear system The plaary gear system has three partsthe sun gear the pla gears and carrier and the internal gear or ring gearThe internal teeth of the ring gear mesh with the pla gear teeth Thus the ring gear rotates with the other parts of the plaary gear system The plag gears are actually one set of gears joined together by a cage called the pla gear carrier or pla pinion carrier The carrier has pins that go through the center of each of the pla gears Thus all the pla gears move together when the pla carrier moves Each pla gear can turn around its pin when the pla gear carrieris stationary When the pla carrier moves the pla gears rotate about the sun gear When the pla carrier is stationary the pla gears rotate about their pins Now the pla gears idle 3How the Plaary System Works The plaary system works on the following principles With one part held stationary torque and power can be applied to a second member to make a third member rotate In other wordswith one of the three members held stationary torque is applied to either of the other two members and output torque is delivered from the third member Ring Gear Stationary Gear Reduction Hold the ring gear stationary The sun gear and pla gears and carrier are now the input and output gears of the system Imagine that input torque is applied to the sun gear to turn it The rotating sun gear causes the pla gears to walk around the outside of the sun gear and inside the ring gear The walking pla gears turn the pla carrier When you hold the ring gear and apply torque to the sun gear the pla carrier turns in the same direction as the sun gear However the carrier turns at a much slower speed The carrier makes less than half a revolution in the time the sun gear makes a plete revolution If the pla carrier were connected to an output shaft that shaft would also turn slower than the input shaft connected to the sun gear This causes gear reduction on the output shaft Of course the gear reduction also causes reduction also causes torque multiplication of the output shaft Sun Gear Stationary Gear Reduction Now hold the sun gear stationary and apply input torque to the ring gear The pla carrier again bees the driven member and the source of output torque In this case the pla gears walk around the sun gears The gear carrier turns more slowly than the ring gear The carrier makes a little more than half a revolution in the time the ring gear makes one plete revolution The ratio of these two parts depends on the numberof teeth in the pla gears and ring gear Since the output gear carrier rotates more slowly than the input ring gear there is gear reduction and gear reduction results in torque multiplication Pla Carrier stationary Reverse Now hold the pla carrier stationary and apply input torque to the sun gear Now the pla gears idle rotate in the opposite direction as the sun gear The rota