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三轴式 刚性 支承 结构 变速器 设计 长安 SC6371

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三轴式刚性支承结构变速器设计【长安之星SC6371】,三轴式,刚性,支承,结构,变速器,设计,长安,SC6371

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本科学生毕业设计三轴式刚性支承结构变速器设计 系部名称： 汽车工程系 专业班级：车辆工程B05-17班学生姓名： 刘旭蕊 指导教师： 石美玉 职 称： 副教授 黑 龙 江 工 程 学 院二九年六月The Graduation Design for Bachelors DegreeThe Design of Three-axis Rigid Support TransmissionCandidate: Liu Xurui Specialty: Vehicle EngineeringClass: B05-17 Supervisor: Associate Prof.Shi MeiyuHeilongjiang Institute of Technology2009-06HarbinSY-025-BY-3毕业设计（论文）开题报告学生姓名刘旭蕊系部汽车工程系专业、班级车辆工程B05-17班指导教师姓名石美玉职称副教授从事专业车辆工程是否外聘是否题目名称三轴式刚性支承结构变速器设计一、课题研究现状、选题目的和意义 1、研究现状 汽车变速器发展经历了100多年，从最初采用侧链传动到手动变速器，到现在的液力自动变速器和电控机械式自动变速器，再向无级自动变速器方向发展。变速器是汽车传动系的重要组成部分，其发展无疑代表着汽车工业的发展，它的设计也是汽车设计的一个重要部分。手动变速器（MT）主要采用齿轮传动的降速原理，变速器内有多组传动比不同的齿轮副，汽车行驶时的换挡就是通过操纵机构使变速器内不同的齿轮副工作。我国汽车工业采用CAD技术，从无到有，至今已有十年的历史。与其他机械产品相比，汽车行业在计算机应用的投入比较多。各汽车厂纷纷引进软硬件并逐步建立了计算机辅助系统。AutoCAD在用户的心目中也变成了二维设计软件的缩影。微型汽车从20世纪80年代引入我国，以其价格便宜，经济实用，机动灵活等优点，在我国吸引了大量消费者，在我国汽车市场中占有较大的份额。随着消费者对汽车安全性、舒适性、经济性和动力性要求的提高及国家排放法规的限制，微型汽车的技术含量不断提高，新型后驱动变速器的设计将会满足车厂和用户更高层次的要求。 2、目的和意义 变速器浮动式结构的齿轮轴，工作时会产生挠度。因此，一方面降低了输出轴的刚性，另一方面造成了啮合齿轮啮合不良，致使齿轮强度降低，增加了运转噪音，影响了整机的性能。为了使变速器结构更加紧凑、合理，承载能力较大，满足匹配发动机之所需，并使齿轮承载能力高，运转噪音低，传递运动平稳，而设计三轴式刚性支承结构变速器，以进一步提升后驱动变速器的性能，增加后驱动微型车市场满足不同层次的需求。二、设计（论文）的基本内容、拟解决的主要问题1、研究的基本内容（1）三轴式刚性支承结构变速器传动机构布置方案（2）变速器基本参数的确定（3）各挡齿轮的设计及校核（4）传动轴的设计及校核（5）轴承的选择及校核（6）同步器和操纵机构的设计选用（7）变速器箱体的设计（8）CAD绘制装配图及零件图2、拟解决的主要问题（1）刚性支承方案（2）参数的确定（3）主要零部件设计及校核（4）AutoCAD绘制装配图及零件图三、技术路线（研究方法）收集资料，知识准备选择车型，确定基本性能参数变速器传动机构布置方案挡数及各挡传动比的确定CAD绘制装配图、零件图完成设计说明书变速器箱体的设计同步器和操纵机构的设计选用主要零部件的设计及计算齿轮参数确定及各挡齿轮齿数分配轮齿强度计算轴的设计及校核轴承的选择及校核轴向尺寸的确定变速器中心距的确定变速器基本参数的确定四、进度安排 （1）知识准备、调研、收集资料、完成开题报告 第1、2周（3.2-3.13） （2）整理资料、提出问题、撰写设计说明书草稿、绘制装配草图 第35周（3.16-4.3） （3）理论联系实际分析问题、解决问题，完成各挡传动比等参数确定；各挡齿轮的设计及校核；传动轴的设计及校核；轴承的选择及校核；同步器和操纵机构的设计选用；变速器箱体设计；CAD绘图等大部分设计内容，中期检查 第69周（4.6-5.1） （4）改进完成设计，改进完成设计说明书，指导教师审核，学生修改 第1014周（5.4-6.5） （5）毕业设计审核 第15周（6.8-6.12） （6）毕业设计修改 第16周（6.15-6.19） （7）毕业设计答辩准备及答辩 第17周（6.22-6.26）五、参考文献1刘惟信.汽车设计M.清华大学出版社，2001.72臧杰，阎岩.汽车构造M.北京：机械工业出版社，2006.7 3王望予.汽车设计（第4版）M.北京：机械工业出版社，2007.9 4余志生.汽车理论（第4版）M.北京：机械工业出版社，2008.1 5王宝玺，贾庆祥.汽车制造工艺学（第3版）M.北京：机械工业出版社，2008.1 6杨可桢，程光蕴，李仲生.机械设计基础（第五版）M.北京：高等教育出版社，2006.5 7殷玉枫.机械设计课程设计M.北京：机械工业出版社，2006.6 8蔡春源.简明机械零件手册M.北京：冶金工业出版社，1996.3 9徐灏.机械设计手册（3）M.机械工业出版社，1991 10刘品.机械精度设计与检测基础（第5版）M.哈尔滨：哈尔滨工业大学出版社，2007.9 11栾焕明.新型后驱动变速器传动系统设计与优化D.哈尔滨工程大学硕士学位论文，2007.3：2045 12向立明.汽车变速器的发展历史及未来趋势J.公路与汽运，2007.1（1）：2141 13宁斌.474汽车变速器倒档锥度环的结构改进J.装备制造技术，2007（1）：7782 14李卉.微型汽车变速器齿轮降噪研究J.中南林学院学报，2000，20（1）：6878 15Liu Weixin,Ge Ping,Li Wei.Study of Optimal Matching Between Automobile Transmission Parameters and Engine,Transportation Systems-1990-,AMD-Vol.108.The Winter Annual Meeting of The ASME,Dallas,Texas,Nov.2530，1990 16John Fenton.Hand Book of Vehicle Design Analysis.Warrendale,PA.,USA:Society of Automotive Engineer,Inc.6571，1996六、备注指导教师意见：签字： 年 月 日附 录How Manual Transmissions WorkIf you drive a stick-shift car, then you may have several questions floating in your head.How does the funny H pattern that I am moving this shift knob through have any relation to the gears inside the transmission? What is moving inside the transmission when I move the shifter? When I mess up and hear that horrible grinding sound, what is actually grinding? What would happen if I were to accidentally shift into reverse while I am speeding down the freeway? Would the entire transmission explode? In this article, well answer all of these questions and more as we explore the interior of a manual transmission.Cars need transmissions because of the physics of the gasoline engine. First, any engine has a redline - a maximum rpm value above which the engine cannot go without exploding. Second, if you have read How Horsepower Works, then you know that engines have narrow rpm ranges where horsepower and torque are at their maximum. For example, an engine might produce its maximum horsepower at 5,500 rpm. The transmission allows the gear ratio between the engine and the drive wheels to change as the car speeds up and slows down. You shift gears so the engine can stay below the redline and near the rpm band of its best performance.Ideally, the transmission would be so flexible in its ratios that the engine could always run at its single, best-performance rpm value. That is the idea behind the continuously variable transmission (CVT).A CVT has a nearly infinite range of gear ratios. In the past, CVTs could not compete with four-speed and five-speed transmissions in terms of cost, size and reliability, so you didnt see them in production automobiles. These days, improvements in design have made CVTs more common. The Toyota Prius is a hybrid car that uses a CVT.The transmission is connected to the engine through the clutch. The input shaft of the transmission therefore turns at the same rpm as the engine.A five-speed transmission applies one of five different gear ratios to the input shaft to produce a different rpm value at the output shaft.A Very Simple TransmissionTo understand the basic idea behind a standard transmission, the diagram below shows a very simple two-speed transmission in neutral:Lets look at each of the parts in this diagram to understand how they fit together: The green shaft comes from the engine through the clutch. The green shaft and green gear are connected as a single unit. (The clutch is a device that lets you connect and disconnect the engine and the transmission. When you push in the clutch pedal, the engine and the transmission are disconnected so the engine can run even if the car is standing still. When you release the clutch pedal, the engine and the green shaft are directly connected to one another. The green shaft and gear turn at the same rpm as the engine.) The red shaft and gears are called the layshaft. These are also connected as a single piece, so all of the gears on the layshaft and the layshaft itself spin as one unit. The green shaft and the red shaft are directly connected through their meshed gears so that if the green shaft is spinning, so is the red shaft. In this way, the layshaft receives its power directly from the engine whenever the clutch is engaged. The yellow shaft is a splined shaft that connects directly to the drive shaft through the differential to the drive wheels of the car. If the wheels are spinning, the yellow shaft is spinning. The blue gears ride on bearings, so they spin on the yellow shaft. If the engine is off but the car is coasting, the yellow shaft can turn inside the blue gears while the blue gears and the layshaft are motionless. Now, lets see what happens when you shift into first gear. First GearIn this picture, the green shaft from the engine turns the layshaft, which turns the blue gear on the right. This gear transmits its energy through the collar to drive the yellow drive shaft. Meanwhile, the blue gear on the left is turning, but it is freewheeling on its bearing so it has no effect on the yellow shaft. When the collar is between the two gears (as shown in the first figure), the transmission is in neutral. Both of the blue gears freewheel on the yellow shaft at the different rates controlled by their ratios to the layshaft. From this discussion, you can answer several questions: When you make a mistake while shifting and hear a horrible grinding sound, you are not hearing the sound of gear teeth mis-meshing. As you can see in these diagrams, all gear teeth are all fully meshed at all times. The grinding is the sound of the dog teeth trying unsuccessfully to engage the holes in the side of a blue gear. The transmission shown here does not have synchros (discussed later in the article), so if you were using this transmission you would have to double-clutch it. Double-clutching was common in older cars and is still common in some modern race cars. In double-clutching, you first push the clutch pedal in once to disengage the engine from the transmission. This takes the pressure off the dog teeth so you can move the collar into neutral. Then you release the clutch pedal and rev the engine to the right speed. The right speed is the rpm value at which the engine should be running in the next gear. The idea is to get the blue gear of the next gear and the collar rotating at the same speed so that the dog teeth can engage. Then you push the clutch pedal in again and lock the collar into the new gear. At every gear change you have to press and release the clutch twice, hence the name double-clutching. You can also see how a small linear motion in the gear shift knob allows you to change gears. The gear shift knob moves a rod connected to the fork. The fork slides the collar on the yellow shaft to engage one of two gears. In the next section, well take a look at a real transmission.A Real TransmissionThere are three forks controlled by three rods that are engaged by the shift lever. Looking at the shift rods from the top, they look like this in reverse, first and second gear: Keep in mind that the shift lever has a rotation point in the middle. When you push the knob forward to engage first gear, you are actually pulling the rod and fork for first gear back. You can see that as you move the shifter left and right you are engaging different forks (and therefore different collars). Moving the knob forward and backward moves the collar to engage one of the gears。Reverse gear is handled by a small idler gear (purple). At all times, the blue reverse gear in this diagram is turning in a direction opposite to all of the other blue gears. Therefore, it would be impossible to throw the transmission into reverse while the car is moving forward - the dog teeth would never engage. However, they will make a lot of noise! 手动变速器如何工作如果你驾驶一台手动小轿车，那么你可能会有几个问题漂浮在脑海中。当移动换挡操纵杆时，是怎样通过变速器中齿轮的联系实现有趣的“H”模式？当我移动操纵杆时，变速器里面是如何工作的呢？当我换错挡并听到可怕的摩擦声时，实际是什么在磨削呢？如果我在高速公路上急行时，突然换倒档会发生什么情况呢？变速器会爆炸吗？在本篇文章中，我们将回答所有这些问题，更要探索手动变速器内部。由于物理学的汽油发动机，故汽车需要传输动力。首先，任何发动机都有一条红界限转速超过最大值时，发动机不会运行也不会爆炸。第二，如果你知道马力是如何工作的，那么你一定知道当马力和扭矩达到最大值时，发动机的转速范围缩小。例如，发动机可能产生的最大马力为5500转。变速器使发动机和驱动车轮之间的传动比变小，以使汽车加速行驶。你变速行驶时，发动机能停留在红界限或界限附近以达到最佳行驶状态。最理想的是，变速器以非常灵活的比率使发动机可以始终运行在单一的、最高性能的转速。这种想法基于连续的变速传动（无级变速器）。无级变速器有近无穷的传动比范围。在过去，无级变速器在成本、大小和可靠性上不能与四档和五档变速器相比，所以没有大量运用于汽车生产中。近年来，无级变速器的改进设计更为常见。丰田普锐斯是一辆使用无级变速器的混合动力型汽车。变速器通过离合器与发动机相连。因此，变速器输入轴与发动机以同样的转速转动。五档变速器适用于五个不同的传动比的汽车，它把输入轴产生的不同转速值传给输出轴。一个非常简单的变速器为了理解一台标准变速器的原理，下面的图表显示了一个非常简单的中间轴式双速传动变速器：让我们看一看图表中的每一部分，理解他们是怎样结合在一起的：发动机的动力通过离合器传给输入轴。输入轴和输入齿轮以一个单个单元连接。（离合器是一种装置，它可以连接和断开发动机和变速器。当你踏下离合器踏