车用永磁缓速器磁-热耦合建模与试验研究

Modeling and Experimental Study of Vehicle Permanent-magnet Retarder with Magneto-thermal Coupling

针对重载货车制动负荷严重超限的问题,提出了一种基于永磁涡流制动原理的车用辅助制动装置—永磁缓速器,其制动力矩可无级调节。为解决永磁缓速器长时间制动产生高温导致的制动力矩衰退、永磁体失磁等问题,采用磁-热双向耦合方法,以涡流盘磁导率和电导率为物理场相互影响因子,建立了缓速器磁-热耦合物理场模型,研究了考虑温度影响的缓速器制动力矩特性,为缓速器优化设计提供理论支持。试制了不同涡流盘材料和散热结构的多个永磁缓速器样机,并进行了台架拖动试验。结果表明,采用磁-热双向耦合时的制动力矩仿真值和试验值吻合更好。

Aiming at the seriously overload braking problem of heavy truck,a permanent-magnet retarder based on the principle of permanent-magnet eddy-current braking is proposed as an auxiliary braking device,whose braking torque can be continuously adjusted.To solve the problem of braking torque decline and the magnet loss of permanent-magnet caused by high temperature due to long-time braking,a scheme of magneto-thermal two-way coupling is adopted and a magneto-thermal coupled model of the retarder is established with the magnetic permeability and conductivity of eddy disk as the mutual influencing factors in physical fields,and the braking torque characteristics of the retarder is studied with consideration of the effects of temperature,providing theoretical supports for the optimization design of the retarder.The trial manufacture and subsequent motoring bench test of several retarder prototypes with different materials and heat dissipation structures of eddy disk are conducted and the results show that with magneto-thermal two-way coupling,the simulated braking torque agree better with the tested one.