基于磁流变液的客车缓速器设计

摘要

The advantages and disadvantages of the traditional eddy current and hydraulic retarder were analyzed in this paper.There exists no lag time in eddy current retarders.However, the large operating current will shorten the battery life.The hydraulic retarder, with low maintenance costs, can provide a larger brake torque with comparatively low weight.The composition and effect of magnetorheological fluid were also described in this paper.With zero magnetic field, the magnetic particles in magnetorheological fluid are very randomly dis-tributed.But there are rules in applied magnetic field for particles to be aligned along the direction of magnetic force lines, showing a chainlike distribution beam.The stronger the magnetic field is, the more obvious the chain packing of the particles and the stronger the shear yield strength of magnetorheological fluid.At last, a coach magnetorheological retarder sketch was proposed, which could work under compression plus shear mode. It is estimated that the vehicle magnetorheological retarder could work with lower current than eddy current re-tarders and work faster than hydraulic retarders.%首先,分析传统电涡流缓速器及液力缓速器优缺点,电涡流缓速器工作时没有时间上的滞后性,但工作电流非常大,使蓄电池很快损坏;液力缓速器能以较小的质量提供较高的制动力矩,维修成本低,但液力缓速器结构复杂,加工装配困难,开始工作及断开时有时间滞后性. 其次,阐述磁流变液组成及效应,在零磁场下磁流变液中的磁性颗粒杂乱无章随机分布,在施加磁场后颗粒规则排列,沿着磁力线方向显示出成束的链状分布. 磁场越强,颗粒的链状排列越明显,磁流变液的剪切屈服强度越强. 最后,设计客车磁流变缓速器结构原理图,该磁流变缓速器工作在压缩与剪切相结合的模式下.据估计,该客车磁流变缓速器能够克服电涡流缓速器工作电流大及液力缓速器时间滞后的缺点 .