【摘要】 为提高铁路运输的安全与效率,以货运列车制动闸瓦上下端的压力分布来评价闸瓦磨耗程度,提出可行的改善措施.首先,对闸瓦制动单元的力学模型进行理论分析,发现对称性结构设计是闸瓦偏磨的主要原因.然后,将闸瓦组件设计成非对称结构,使其作用面上的压力重新分布,达到改善偏磨的效果.最后,在Recur Dyn多体动力学软件环境中构建制动系统的刚柔耦合动力学模型,通过仿真实验,对比分析改善前后制动闸瓦上下端的应力分布.闸瓦制动单元的理论分析表明,当非对称闸瓦的偏心距取27 mm时,理论上闸瓦上下端压力比由1.19降为1.00.仿真结果也说明,对称性闸瓦上下端压力分布很不均匀,改进设计后的非对称闸瓦,其偏磨得以明显改善.研究成果为铁路货车制动系统的性能改进提供理论依据及技术支持.更多还原

【Abstract】 For improving the safety and efficiency of railway transportation,the pressure distributions of brake shoes on upper and lower ends are employed to evaluate the degree of wear,and then a feasible improvement method is proposed. Firstly,theoretical derivation is performed according to the mechanical model of the brake unit,discovering that the symmetrical structure design is a major cause of eccentric wear. Then,an unsymmetrical brake shoe is presented,which makes the pressures on upper and lower ends redistribute and alleviates the degree of eccentric wear accordingly. Finally,constructing a rigid-flexible coupling dynamic model for the braking system in Recur Dyn. Through comparative simulation experiments,the stress distributions on the upper and lower ends of brake shoes is delerminated. Theoretical analysis of the brake shoe unit indicates that when the offset distance is 27 mm,the ratio of pressures declines from 1. 19 to 1 ideally. Besides,simulation results also prove that the pressure distribution on the symmetrical brake shoes is quite nonuniform,and the eccentric wear reduces significantly with unsymmetrical structure shoes. The results provide theoretical foundation and technical support for the performance improvement of the braking system.更多还原