本科畢業設計（論文） 英文資料翻譯 作 者 ：周 杰 指導教師 ：孫飛豹（副教授） 學科、專業：車輛工程 沈陽理工大學應用技術學院 2011 年 12 月 20 日 transmission used in automobiles A standard transmission or manual transmission is the traditional type of transmission used in automobiles. The manual or standard transmission consists of a series of gears, synchros, roller bearings, shafts and gear selectors. The main clutch assembly is used to engage and disengage the engine from the transmission. Heliacal cut gears are used to select the ratio desired the sector fork move gears from one to another by using the gearshift knob. Synchros are used to slow the gear to a stop before it is engaged to avoid gear grinding, the counter shaft hold the gears in place and against the main input and output shaft. A stick shift transmission has no torque converter so there is no need for a transmission cooler. A stick shift transmission needs a simple fluid change for proper service. (there is no transmission filter in a stick shift transmission). Transmission Shifter - 1 - Most manual transmissions have one reverse gear and four to six forward gears. Some cars also have eight forward gears while thirteen to twenty-four gears are present in semi trucks. To differentiate among the available standard transmissions, they are addressed by the number of forward gears. For example, if the standard transmission has five gears, it will be referred to as 5-speed standard transmission or 5-speed standard. Typical Standard Transmission Configuration Inside the transmission shafts contain all forward and reverse gears. Most transmissions contain three shafts: input shaft, output shaft and counter or lay shaft. Other than standard transmission, there are other transmissions like continuously variable transmission, automatic transmission and semi-automatic transmission. In the manual transmission, a pair of gears inside the transmission selects the gear ratios. Whereas, in an automatic transmission, combination of brake bands and clutch packs control the planetary gear which selects the gear ratio. If there is a provision to select a gear ratio manually in automatic transmissions, the system is called a semi-automatic transmission. The driver can select from any of the gears at any point - 2 - of time. In some automobiles like racing cars and motorcycles that have standard transmissions, the driver can select the preceding or the following gear ratio with no clutch operation needed. This type of standard transmission is known as sequential transmission. In this transmission the clutch is still used for initial take off. Clutch and Flywheel Assembly The main clutch plays the role of a coupling device which separates the transmission and the engine. If the clutch is absent and the car comes to a stop the engine will stall. In automobiles, the clutch can be operated with the help of a pedal located on the floor of the vehicle. In an automatic transmission instead of a clutch, a torque converter is used to separate the transmission and engine. - 3 - Typical Stick Shift Patterns A desired gear can be selected by a lever which is usually located on the floor in between the driver and passenger seat. This selector lever is called the gear lever or gear selector or gear shift or shifter. This gear stick can be made to move in right, left, forward and backward direction. When the gear is placed on the N position or neutral position, no gear will be selected. To move the car in the backward direction, the R gear or reverse gear should be selected. Standard transmissions are more efficient and less expensive to produce than automatic transmissions. A Standard transmission is about 15% more efficient compared to an automatic transmission. Standard transmissions are generally stronger than automatic transmissions and off road vehicles take advantage of a direct gear selection so they can withstand rough conditions. Less active cooling is also required in manual transmission system because less power is wasted. - 4 - Popular Problem Checks Car will not go into gear Clutch disc is broken completely Internal transmission damage Failed clutch master cylinder Seized clutch slave cylinder Broken clutch fork pivot Broken clutch cable Car goes into gear but it fades out or is slipping Clutch is worn out and needs replacement Clutch is oil soaked from a external engine oil leak Car makes grinding noise while operating or shifting gears One of the roller or thrust bearings has failed The gear synchro is worn out not forcing the gear stop before it is engaged causing a grinding gear. A counter or main shaft bearing has failed causing misalignment of the gears Troubleshooting Noise and Problems If the vehicle is running and a whirring sound is heard, then it goes away when the clutch is depressed, the transmission input bearing has failed. If the transmission is quiet in neutral but when you depress the clutch a squeaking noise is observed, a clutch throw out bearing has failed. Tips:Never let little noises go unattended； a small noise can cause a large noise and transmission operation failure. Never overload a vehicle or tow beyond the capacity this can cause premature transmission failure. - 5 - 汽車變速器 汽車傳統變速器是那種標準的手動變速器。標準手動變速器由一系列的齒輪、同步器、軸承、軸和換檔撥叉組成。主離合器總成是用來啟動和切斷傳動系與發動機。 齒輪組用來選擇理想的傳動比，通過換檔桿帶 動撥叉把齒輪從一個位置移到另一個位置來實現。同步器是用來在齒輪傳動裝置嚙合以前使齒輪減速，避免齒輪磨損。中間軸控制齒輪組在合適的位置并且使輸出軸與主動輸入在反向。手動變速器沒有變矩器，所以也沒有不要配冷卻系統，正確保養手動變速器只需要更換變速器油即可（手動檔變速器沒有自動變速器潤滑油過濾器）。 換檔桿 絕大多數手動變速器油一個倒檔齒輪組和 4 到 6 個前進檔齒輪組。一些汽車也有 8 個前進檔齒輪組，然而 13 到 24 齒輪組的只在半掛貨車上使用。區分手動變速器的有效途徑是他們確切的前進檔齒輪組數。例如，如果一個手動 變速器有 5 個前進檔齒輪組，它會叫 5 速度標準變速器，或標準 5 檔。 - 6 - 標準變速器典型配置 在變速器里面的傳動軸上，有全部的前進檔齒輪組和倒檔齒輪組。大多數的手動變速器都是三軸變速器：輸入軸、輸出軸和中間軸或副軸。除了標準手動變速器，還有其他變速器像無級變速器、自動變速器和半自動變速器。就手動變速器，靠，變速器內的齒輪副選擇傳動比。然而，在自動變速器里，靠組合制動器、離合器群控制行星齒輪組來選擇傳動比。 如果有一款能手動選擇傳動比的自動變速器，那么這個系統叫做半自動變速器。駕駛員可以在任何時候選擇傳動比。在 一些車輛上，像賽車和摩托車上安裝標準變速器，駕駛員能夠選擇上一個或下一個檔位而不需要離合器。這種類型的變速器以能連續變數著稱。在這種傳動裝置中離合器依然會用于起步。 離合器和飛輪總成 - 7 -