1、毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文译文题目： Automobile Transmission Design 汽车变速器的设计 学生姓名： 学 号： 专 业： 所在学院： 指导教师： 职 称： 20xx年 2月 27日说明：要求学生结合毕业设计（论文）课题参阅一篇以上的外文资料，并翻译至少一万印刷符（或译出3千汉字）以上的译文。译文原则上要求打印（如手写，一律用400字方格稿纸书写），连同学校提供的统一封面及英文原文装订，于毕业设计（论文）工作开始后2周内完成，作为成绩考核的一部分。外文原文Automobile Transmission DesignAbstractThe
2、 topic of this project is a design of transmissions for a medium-size truck. The adoption of suitable designs and layout enables the effective utilization of engine to improve the trucks motility and economy. The design was referred to parameters of Beijing Foton truck and relevant books. Via a comp
3、rehensive demonstration, the data was collected from various components of the transmission which were modeled by Solidworks. The transmission is a five-speed transmission, including five forward gears and one reverse gear, applying advanced monolithic structure of the intermediate shaft and the shi
4、ft lock ring-type synchronizer. The gearbox possesses a compact structure, a small size, high transmission efficiency, and a larger ratio range, with good economy and dynamic performance.Keywords: five-speed, intermediate shaft, synchronizer.1. IntroductionThe role of transmission:Transmission chang
5、es the speed of the engine and exports different rotational speed. At low rotational speed, high torque can be obtained. High speed has better efficiency but the torque is low. So, when you start a machine you need to start at low speed and after running then change high rotational speed maintaining
6、 a high efficiency.Specifically, in order to ensure good transmission performance, it should meet the following requirements.1) Choose the correct gear shift number and transmission gear ratios, and make the optimal matching of engine parameters to ensure that the car has good power and economy.2) S
7、et neutral to ensure the car engine and the transmission can separate for a long time.3) Set reverse, so that the car can travel backwards.4) Set the power output apparatus.5) Shift quickly, labor-saving, easily.6) Reliable. During driving, the transmission cannot out-of-mesh, random mesh.7) Transmi
8、ssion should have a high efficiency.8) Transmission should be simple, smooth, no noise.2. Demonstration program2.1 Select transmission typeThere are many types of transmissions.By the number of forward gears, transmissions can be divided into three, four,five-speed and the multi-speed transmission,
9、five speed transmission was chosen.According to the shaft of different form, transmission can be divided into fixed shaft and rotating shaft (often with planetary gear transmission) two kinds of transmissions. The main characteristic of fixed axis transmission is easy to realize automatic shift wide
10、ly used. Two shaft transmission for front engine front-wheel drive. The shaft of rotation type is mainly used for hydraulic mechanical transmission. Fixed shaft type was chosen.According to the number of different shafts, the transmission can be divided into two-shaft transmission, layshaft transmis
11、sion and multiple shafts transmission.2.1.1 Two-shaft transmissionIf the transmission ratio is small, we often choose two shaft types. It has the following characteristics.1. The gearbox output shaft and the main driving gear speed reducer make it an organic whole.2. When the engine is longitudinall
12、y mounted, the main reducer can use spiral bevel gear or hypoid gear, when the engine is held horizontally, it is tapped with a cylindrical gear, thereby simplifying the manufacturing process.3. The other gears adopt constant mesh gear transmission, except the reverse gear drive.4. Most of the synch
13、ronizer of gears at the end of the output shaft.5. If low gear transmission is relatively large, the size of the structure increases, it no longer has the above advantages, it can only drive relatively small conditions before using this program.6. Two-shaft transmission does not have directly gears,
14、 therefore, working at high speed, gears and bearings are bearing, gear noise, and easy to be damaged.2.1.2 Layshaft transmissionFrom a structural view, there are three shafts: the first and the second shaft are in the same line, and they are directly shifted. When using direct shift transmission, g
15、ears, bearings and the second shaft are not loading bearing. The engine torque through the first and second shaft have direct output, and the transmission has high transmission efficiency - up to 90 %. This means that it has less wear and long service life, thus, noise is also smaller. Because the efficiency of direct gear is higher than the other forward gears, it increases the life of the transmission. When the transmission power is transmitted through the first shaft (the intermediate gear shaft and
