基于磁流变和电涡流效应的汽车新型缓速器的设计与试验

Design and Test of Novel Vehicle Retarder Based on Magnetorheological and Eddy-current Effects

随着汽车向重大型化发展,制动安全问题日益突出。加装辅助制动装置是实现重大型车辆安全制动的重要途径之一。磁流变制动器具有制动力矩稳定、噪声小和体积质量小等特点,能有效弥补传统辅助制动装置低速性能差等不足。本文中提出利用磁流变效应与电涡流效应进行联合缓速制动的新思路,分析新型磁流变缓速器的工作原理,设计并研制双盘式对称结构的新型缓速器,建立其制动力矩数学模型并从理论上分析不同参数对制动性能的影响。根据重大型汽车大功率制动的工作特点,搭建制动性能测试平台,进行制动力矩特性试验。理论分析与试验结果表明:新型磁流变缓速器具有低速制动性能稳定、高速制动力矩大的特点,其制动力矩特性满足重大型汽车制动要求。

With motor vehicle developing toward heavy and large-size,its braking safety issue becomes increasingly prominent.Additionally installing auxiliary braking device is one of the important ways to achieve the safety braking for heavy-duty vehicles.Magnetorheological(MR)brake has advantageous features of stable braking torque,low noise and small volume and mass etc.,so is able to remedy the inadequacies of traditional auxiliary braking devices,e.g.the poor performance at low speeds.A new idea of combined retarding braking by utilizing both MR and eddy-current effects is put forward,the working principle of novel MR retarder is analyzed,the double-disk symmetric structure of novel retarder is designed and developed,the mathematical model for its braking torque is established and the effects of different parameters on braking performance are theoretically analyzed.According to the working features of high-power braking in heavy-duty vehicles,a testing platform for braking performance is constructed,and a test on braking torque characteristics is conducted.The theoretical analysis and test results show that the novel MR retarder has the features of stable braking performance at low speed and large braking torque at high speed,with its braking torque characteristics meeting the braking requirements of heavy-duty vehicles.