【作者】 叶乐志；

【导师】 李德胜；

【作者基本信息】 北京工业大学 ， 机械工程， 2012， 博士

【摘要】 汽车缓速器是一种非摩擦性的辅助制动装置，它在车辆制动之前消耗大部分行驶动能，可以有效提高车辆行驶的安全性和连续制动性能，降低车辆使用成本。上世纪中期许多欧洲国家已颁布交通法规，将缓速器列为汽车的标准配置。近年来，国内随着相关法规的颁布，汽车缓速器也逐步获得应用推广。目前，电涡流缓速器和液力缓速器是国内外应用最广泛的两种产品，但电涡流缓速器制动力矩热衰退严重，体积重量大且耗能高，而液力缓速器价格高，在性价比方面难以满足国内重型货车的要求，致使国内重型货车的缓速器安装率不足1%。因此，研究开发具有自主知识产权的高性价比缓速器，对于打破国外缓速器技术垄断，保障行车安全，提高国产汽车的自主创新能力具有重要意义。上世纪90年代，日本首次研制成功了一种革命性的永磁缓速器，具有不耗电、重量轻、结构紧凑等优点，但没有得到大规模推广。本文针对永磁缓速器制动力矩小和持续工作能力差等问题，系统研究了永磁缓速器设计的理论和关键技术，提出了一种采用永磁涡流制动原理和水冷散热技术相结合的新型汽车缓速器——水冷式永磁缓速器，并进行了大量的台架和实车试验，形成了水冷式永磁缓速器性能评价体系，取得了许多重要成果。本论文主要章节和内容安排如下：第一章绪论部分概述了汽车辅助制动装置作用，安装必要性，国内外法规和应用情况，以及研究意义。介绍了各种汽车缓速器的种类、工作原理、性能比较以及永磁缓速器设计理论和结构的研究进展。通过总结缓速器存在的共性技术问题，提出永磁缓速器的发展方向。综述涡流制动理论和多物理场理论的研究进展，从而提出永磁缓速器设计理论的研究方法。第二章提出水冷式永磁缓速器结构及原理。先详细介绍了日本传统永磁缓速器的结构、工作原理、控制方法、安装方法、特点以及使用效果。为克服传统永磁缓速器热衰退严重的问题，提出了一种采用水冷散热的新型永磁缓速器，并介绍了其基本结构和工作原理。该缓速器能够保持较低的工作温度，持续工作时基本不发生制动力矩热衰退，大大提高永磁缓速器的制动性能和持续工作能力。根据整车安装要求，提出了三种适配于重型货车和大型客车的水冷式永磁缓速器结构。研究了水冷式永磁缓速器与整车的电气、散热和制动性能等方面的匹配特性，设计了缓速器电子控制单元和整车冷却系统水管布置方案，并提出了水冷式永磁缓速器制动力矩与车重的匹配关系。第三章建立了水冷式永磁缓速器的数学模型。从制动减速度和制动距离两方面评价了缓速器对汽车制动性能的影响，详细分析了新型缓速器单独制动和联合制动时的制动过程。基于电枢反应理论和迭代法求解了缓速器瞬态涡流场，得到了制动力矩和制动功率的解析公式，揭示永磁缓速器制动过程中瞬态电磁场变化规律，建立永磁缓速器的电磁场数学模型。通过分析水冷式缓速器热量传递过程的换热方式、传递路径和边界条件，建立了永磁缓速器温度场的数学模型。分析涡流去磁场和比磁导分布，得到永磁体动态工作点，从而建立永磁体高温失磁的数学模型，提出了分析永磁缓速器中永磁体失磁分析方法。第四章建立了永磁缓速器多场耦合模型。建立和数值求解电-磁-热场耦合模型，应用电磁场分析软件得到了磁场和涡流分布图，可视化揭示了永磁缓速器涡流制动的机理。建立和数值求解热-流场耦合模型，应用计算流体力学（CFD）分析软件获得了缓速器定子和永磁体温度场分布图，可视化揭示了定子水道内液体冷却规律。采用半拉格朗日运动坐标系方法建立永磁缓速器的电-磁-热-流场耦合模型，通过试验表明，多场耦合计算结果比单场分析结果更接近试验值。第五章研究了永磁缓速器设计的关键技术。通过搭建涡流制动实验平台，发现缓速器低速区制动力矩与吸力近似呈线性的规律，提出一种静态吸力设计方法。利用数值模拟方法求解了缓速器定子材料的电导率、磁导率、铜或铝材料以及镀覆层对制动力矩的影响，并得到了制动力矩与气隙长度、定子厚度、永磁体形状、屏蔽转子厚度之间的关系曲线。通过试验设计法和Rosenbrock法优化了缓速器结构，开发了汽车永磁缓速器集成设计平台。第六章研究了永磁缓速器试验方法。设计了水冷式永磁缓速器的台架试验和底盘测功机试验方案，提出了车载道路试验系统和方法，将所研制的水冷式永磁缓速器进行了台架、底盘测功机和车载道路试验，形成了水冷式永磁缓速器制动性能评价体系。最后为本文的结论部分以及未来研究展望。更多还原

【Abstract】 Auto retarder, which is a non-contact auxiliary braking device for vehicle, canreduce the driving costs. It consumes most of the vehicle kinetic energy before itbrakes, so it can effectively improve driving safety and continuous brakingperformance. Many European countries have enacted the retarder laws at themid-nineteenth century, which required the retarder as standard auto parts. Recently,retarders are applied and popularized gradually in China as the promulgation ofrelevant laws and regulations. At present, eddy current retarder (ECR) and hydraulicretarder (HR) have been used widely at home and abroad. ECR has manydisadvantages, such as the severe hot recession of braking torque, bulk density andhigh energy consumption. HR’s price is so high that few heavy vehicles install it. It isdifficult to meet the requirements of the domestic heavy vehicle, so the retarderinstallation rate of heavy vehicles is less than1%. Therefore, it is great significance toresearch highly cost-effective retarder that has independent intellectual property. Itcan break the monopoly of foreign retarder, ensure the safety of heavy vehicle, andimprove the independent innovation capability of domestic cars.In the1990s, Japan developed a novel air-cooled permanent magnet retarder(PMR) for the first time, which has no power-consumption, light weight and compactstructure. However, it doesn’t get large-scale promotion. In order to overcome thebraking performance thermal recession problem of PMR, a new type PMR is designusing water-cooled method in this dissertation. The systemic theory and keytechnology of water-cooled PMR are researched, and lots of bench and real vehicletests are made. Performance evaluation system of water-cooled PMR is formed, andmany important results are obtained. Main chapters of the dissertation are as follows:Chapter I introduces the role of auxiliary braking device for vehicle, thenecessary of installation, the domestic and foreign laws, the application, and researchsignificance. Retarder types, working principles, performance comparisons, andprogress in PMR design theory and structure are introduced. The developmentdirection of PMR is proposed by summing up common technical problems of theretarder. The progress of eddy current braking and multi-physics coupling theory arereviewed, and the research methods of PMR design theory are proposed.Chapter II proposes a structure and principle of water-cooled PMR. At first, thestructure of Japanese traditional PMR, the working principle, the control method, theinstallation method, the characteristics and the used effects are described in detail. Thebasic structure and working principle of water-cooled PMR are introduced. The water-cooled PMR maintains low working temperature, braking performance does notoccur thermal recession and the continuing work capacity is improved greatly.According to the vehicle installation requirements, three kinds of water-cooled PMRstructure which meet the requirement of heavy vehicles and buses are proposed. Thematching characteristics of water-cooled PMR with the electrical, cooling and brakingperformance of the vehicle are studied. The electronic control unit and vehicle coolingsystem pipes layout of PMR are designed, and the matching relationship between thebraking torque and vehicle weight are proposed.Chapter III builds a mathematical model of water-cooled PMR. The PMRbraking performance for vehicles is evaluated by the brake deceleration and brakingdistance. The PMR braking process of the separate braking and combined braking isanalyzed. The transient eddy current field of PMR is solved by armature reactiontheory and iterative methods, and the analytic formulas of the braking torque andbraking power are obtained. The change law of the transient electromagnetic field isrevealed in braking process of PMR, and the mathematical model of PMRelectromagnetic fields is established. A temperature mathematical model of PMR isestablished by the analysis of the heat transfer process, heat transmission path andboundary conditions. In order to analyze permanent magnet (PM) demagnetization onhigh-temperature in PMR, PMR mathematical model is established firstly, and theboundary conditions of finite element analysis are determined. Then eddy currentfield distribution is gained by solving eddy current demagnetization field, and PMdynamic permeance coefficient is obtained. Combined with the PM demagnetizationcurve analysis, the demagnetization properties are analyzed.Chapter IV builds a multi-physics coupling model of water-cooled PMR. Theelectric-magnetic-thermal field coupling model is established and solved numerically.The eddy current braking mechanism of PMR is visualized by electromagneticsoftware and the magnetic field and eddy current distribution are obtained. Theheat-fluid field coupling model is established and solved numerically. Thewater-cooling law in the stator is visualized by computational fluid dynamics (CFD)software. The temperature distribution of PMR is obtained. Theelectric-magnetic-thermal-fluid coupling model is established by semi-Lagrangemoving coordinate system. The tests show that the multi-field coupling calculationresults are closer to experimental values.Chapter V studies the key technology of PMR design. The approximate linearrelationship between low-speed braking torque and suction is found by eddy current brake experiment platform. The design method of static suction is proposed. Thebraking torque influence of stator material conductivity, permeability and the platinglayer is discussed by finite element method, and the relationships between brakingtorque and air gap length, stator thickness, PM shape, shielded rotor thickness areobtained. PMR structure is optimized by experimental design method and theRosenbrock method, and the integrated design platform of PMR is developed.Chapter VI studies the test methods of water-cooled PMR. The test bench andchassis dynamometer test program for water-cooled PMR are designed. The systemand method of vehicle road tests for PMR are proposed. The water-cooled PMR istested by bench, chassis dynamometer and car road. The braking performanceevaluation system of water-cooled is formed.Finally, the dissertation conclusion and future research outlook are proposed.更多还原