蜗轮箱体工艺及夹具设计(钻孔和镗孔）【全套含CAD图纸、文档说明书资料】
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全套含CAD图纸、文档说明书资料
工艺及镗孔夹具设计全套CAD图纸
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钻孔
镗孔
工艺及镗孔钻孔夹具设计【
蜗轮箱体
镗孔钻孔
工艺及镗孔夹具设计【
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机械与电气工程学院 毕业设计（论文）外文翻译 所在学院： 班 级： 姓 名： 学 号： 指导教师： 合作导师： 年 12 月 9 日原文：DESIGN AND USE OF AN EDDY CURRENT RETARDERIN AN AUTOMOBILEC. Y. LIU*, K. J. JIANG and Y. ZHANGSchool of Automobile Engineering, Jiangsu Teachers University of Technology, Changzhou 213001, China(Received 21 January 2010; Revised 13 December 2010)ABSTRACTIn this study, the structure and working principles of an eddy current retarder acting as an auxiliary brake set is introduced in detail. Based on the principle of energy conservation, a mathematical model was developed to design a retarder whose nominal brake torque is 1, 900 Nm. According to the characteristics of the eddy current retarder, an exclusive test bed was developed and used for brake performance measurements. The main technical parameters, such as the brake characteristics, temperature characteristics and power consumption, were measured with the test bed. The test data show that the brake torque of the eddy current retarder obviously decreased in the continuous braking stage and that there is a certain amount of brake torque in the normal driving state because of the remnant magnetism of the rotor plate. The mathematical model could be used to design an eddy current retarder. The exclusive test bed could be used for optimization of an eddy current retarder as well as for R&D of a series of products.KEY WORDS : Auxiliary brake, Eddy current retarder, Mathematical model, Design, Test1. INTRODUCTIONModern automobile design is focused on driving safety,comfort and environmental protection. With the increase in driving speeds and loads, the main brake system is no longer satisfactory for meeting the braking requirements of heavyduty vehicles and buses. Because of space constraints, it is hard to increase the braking efficiency of the main brake system through improved design. Traffic accidents usually occur when brake plates or brake drums become overheated after the main brake system has been working for a long time. This is especially true for long downhill routes.Technology laws have been put in place in many nations requiring that auxiliary braking devices must be installed for specific vehicles. Auxiliary braking devices include exhaust brakes, eddy current retarders, engine brakes and hydraulic retarders. The eddy current retarder is the most common type of auxiliary braking device.Because it is a non-contact, continuous type of brake set,the eddy current retarder can improve comfort, especially in the automobiles used in the urban setting that need to brake frequently in the normal course of driving. This device is not used for stopping an automobile; it is only used as a complement to the main brake system. After an eddy current retarder is installed in an automobile, the frequency of main brake system use decreases, so the life of the brakes is extended. Because most of brake load is taken on by the eddy current retarder, the temperature rise in the brake disc or drum is reduced, and the braking efficiency of the main brake system is improved. Therefore, the safety of the automobile is also enhanced. Because the main brake system gets used rarely, the brake noise and dust can also be reduced, so this system benefits the environment. Currently, in heavy automobiles and large-scale passenger cars, the eddy current retarder has a standard configuration. However, the design technology of eddy current retarders needs to be perfected and developed further.2. ANALYSIS MODEL2.1. Structure and Working Principle An eddy current retarder is made up of eight cores, an air gap, coils and rotor plates, as shown in Figure 1. A coil is installed on the cylindrical surface of a core. The coil creates the windings. There is an even number of windings,and they are distributed equally around the circumference of the core. When the windings of the eddy current retarder are electrified, the kinetic or potential energy of the automobile can be transformed into thermal energy and dissipated into the atmosphere by a wind tunnel cast in the rotor plate, according to the electromagnetic principle.3 TESTING AND ANALYSIS3.1. Test-bed Structure and Operation The developed test bed was made up of a frequency conversion DC motor, a raising gearbox, an adjustable inertia flywheel group, a speed regulating device, and a series of sensors, such as a temperature sensor and a current sensor. The principle diagram of the test bed is shown in Figure 4. A DC motor was used for driving the raising gearbox. The eddy current retarder was connected with the transmission shaft. When an automobile is in a normal driving state, its kinetic energy is equivalent to the kinetic energy of the raising gearbox and the adjustable inertia flywheel group, so the developed test bed could model an automobile under different loads. Three temperature sensors were used for measuring the temperature rise of the two rotor plates and the windings. The torque and speed sensor was used for measuring the brake torque generated in the braking process and the rotational speed of the main shaft. The excitation voltage and excitation current was Figure 3. Design example of an eddy current retarder.Table 1. Calculated values of the brake characteristics for the eddy current retarder.Characteristics Rotational speed (r/min) 200 400 600 800 1 000 1 200 Brake torque (Nm) 956 1468 1515 1529 1526 1506 Brake power (kW) 20.1 61.6 95.4 128.4 160.2 193.5 Figure 4. Principle diagram of the test bed。614 C. Y. LIU, K. J. JIANG and Y. ZHANG measured in order to study the excitation power and the power consumption characteristics of the eddy current retarder. Fans were used to simulate the wind speed in the process of running, and they also made it possible to simulate the actual thermal conditions of the eddy current retarder and could be used to cool the eddy current retarder rapidly. Test data were collected by the computercentralized control.The test bed is shown in Figure 5. The test-bed operation process was as follows: First, the DC motor was started to drag the main shaft up to the intended rotational speed. The moment of inertia of the flywheel group was used to simulate the equivalent kinetic energy of running an automobile as an energy input of the eddy current retarder.Second, the windings were electrified in different shifts for field excitation,then the parameters, including the brake torque performance, the temperature performance and others, were measured.3.2. Testing Capabilities and Test ItemsThe inertia of a 320 T full-load automobile could be simulated in the test bed. The rotational speed range of the main shaft was 0-3000 r/min. The following test items were performed on the test-bed. The brake torque rotational speed performance test: the brake torque generated by the eddy current retarder varied with the rotor speed. The brake torquetime characteristic, namely, the continuous brake performance test: the brake torque of the eddy current retarder varied with time at a constant rotational speed. The temperature rise-time performance test: the temperature in the rotor plates and the stator changed with time as the eddy current retarder worked. The brake torque-temperature performance test: the brake torque changed with temperature in the rotor plate. The power consumption performance test: the working current and voltage in the windings varied with time as the eddy current retarder worked.3.3.Analysis of the Test ResultsThe test ambient temperature was 20oC, and the air pressure was 0.1 MPa. The fourth brake shift of the retarder was used. From Figures 6 and 7, as the brake timeincreased, the temperature in the rotor plate went up rapidly and then rose slowly. Joule heat generated by the eddy current in the rotor plate reached its steady state with the heat dissipating capacity of the blades. The maximum temperature on the latter rotor plate surface was approximately 505.6oC, and the temperature on the stator went up slowly compared with that on the rotor plate.When the wire was selected, a certain level of temperature tolerance must be considered.4 CONCLUSIONA mathematical model of the eddy current retarder was developed. Based on this model, a brake torque retarder was designed. Many performance parameters were measured in an exclusive test bed. The major conclusions obtained are given below:(1) The eddy current retarder that was designed met the requirements, which indicates that the mathematical model of brake torque developed in this study could be helpful for designing the product.(2) Many performance parameters of the eddy current retarder could be measured in the test bed, and the test bed that was developed was based on design optimization of an eddy current retarder and R&D on a series of products.(3) The brake torque dropped by approximately 40% after the temperature in the rotor plate reached its maximum value on the continuous stage. On the one hand, an excessive decline in the brake torque had a serious effect on the braking stability. On the other hand, the temperature rise in the rotor plate affected the life of the eddy current retarder. Meanwhile, it was adverse to safe driving. Certain actions must be taken to limit the temperature rise, such as implementing temperatureprotection or time protection.译文： 在汽车中一个电涡流缓速器的设计与应用C. Y.刘*，K. J.江和Y张中国常州江苏技术师范学院，汽车工程学院（2010年1月21日，2010年12月13日修订）摘要-在这项研究中,结构和工作原理及一个电涡流缓速器制动组表演作为一种辅助进行了详细的介绍。根据能量守恒原理,开发了一个数学模型,设计了一种缓速器制动力矩的名义为1,900 N米。根据电涡流缓速器的特点,研制了专用实验床并用于制动性能的测量。主要技术参数,如制动特性、温度特性和能量消耗,与试验测定了床上。试验数据表明,制动器制动力矩的明显降低电涡流缓速器制动阶段连续且有一定的制动力矩在正常的驾驶状态因为残的磁转子盘。该数学模型可用于电涡流缓速器设计。独家测试床可以用于电涡流缓速器的优化，以及用于研发的系列产品。关键词:辅助刹车,电涡流缓速器的数学模型,设计、测试1 介绍现代汽车的设计是集中在行车安全、舒适、环保。新增的驾驶速度和荷载作用下,不再是主要制动系统的制动要求满足会议的heavyduty车辆和公共汽车。由于篇幅的限制,很难提高制动效率的主要制动系统,通过完善的设计。交通事故通常发生在主刹车系统已经很长一段时间的工作时，刹车片或制动鼓过热。这尤其适用于长坡的路线。科技法律已经到位, 需要特定的车辆必须安装辅助制动装置的，许多国家尤其如此。辅助制动装置包括排气制动器，电涡流缓速器，发动机制动系统和液压缓凝剂。电涡流缓速器辅助制动装置为最常见的类型。因为它是一种非接触式，连续式制动设置，电涡流缓速器可以提高舒适度，尤其是在城市环境中，需要在正常驾驶过程中经常刹车的汽车。此设备是用于停车的汽车;只用它作为主刹车系统的补充。经过电涡流缓速器是安装在汽车的制动系统使用跌幅的频率，所以刹车的寿命延长。由于大部分制动负载是电涡流缓速，刹车盘或鼓的温升降低，主刹车系统的制动效率提高。因此，汽车的安全性也增强。由于主制动系统很少被使用，刹车也可以减少噪音和灰尘，使这一制度有利于环境。目前，重型汽车和大型客车，电涡流缓速器的标准配置。然而，电涡流缓速器的设计技术需要进一步完善和发展。2 分析模型2.1。结构及工作原理的电涡流缓速器是由八个内核，气隙，线圈和转子板，如图1所示。线圈安装在圆柱表面的一个核心。线圈创建绕组。有一个绕组的偶数，和他们同样围绕核心的圆周分布。当绕组的电涡流缓速器是电气化，汽车的动能或势能可以转化为热能消散到大气中，在转子上的板蒙上了风洞，根据电磁原理。3测试与分析3.1试验台的结构和操作测试床是由一个直流电机,变频调速,可提高齿轮转动惯量飞轮组,调速装置,以及一系列的传感器,如温度传感器和一个电流传感器。原理图测试床被显示在图4。一个直流电机驱动的用于提高变速箱。电涡流缓速器并与传动轴。当一辆汽车是在一个正常的驾驶状态,其动能等效为动能增加变速箱和可调整的惯性飞轮集团
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