Abstract: Setting up radial mechanisms was the main measure to solve the contradiction between serpentine stability and curve passing performance of railway vehicles. However, the conventional lever-type forced-guided steering rack operated in a low-equivalent taper state, where the presence of the linkage exacerbated the vehicles primary-hunting, which in turn led to a decrease in vehicle stability. Aiming at the above-mentioned defects of the traditional lever-type forced-guided bogie, a composite radial mechanism was proposed. This radial mechanism enabled the vehicle to operate in small radius curves with the function of forced guidance, and the vehicle operated in large radius curves or straight lines so that the function of forced guidance was invalidated, thus the shortcomings of the traditional forced-guided bogies were overcome. Based on the working principle of the composite radial mechanisms, the numerical simulation model and control module of the mechanisms were established. Then MATLAB/Simulink was used to jointly simulate the numerical models of the composite radial mechanisms and the dynamics models of the subway vehicles to study the effects on the dynamics performance of the vehicle systems. Then the results were verified by bench testing. The results show that the composite hydraulic radial mechanisms ensure the vehicle has good curve passing performance, and greatly improves the stability of the vehicles.

Key words: metro vehicle, radial bogie, curve passing performance, composite radial mechanism, serpentine smoothness

摘要： 设置径向机构是解决铁道车辆蛇行稳定性与曲线通过性能之间矛盾的主要措施，然而，传统的杠杆式迫导向转向架在低等效锥度状态下运行时，由于连杆的存在加剧了车辆的一次蛇行，进而导致车辆的稳定性下降。针对传统杠杆式迫导向转向架存在的上述缺陷，提出了一种复合型径向机构，该径向机构使车辆在小半径曲线运行时具有迫导向的功能，车辆在大半径曲线或直线上运行时迫导向功能失效，从而克服了传统杠杆式迫导向转向架存在的不足。基于复合型径向机构的工作原理，建立了该机构的数值仿真模型和控制模块，然后采用MATLAB/Simulink对复合型径向机构数学模型和地铁车辆动力学模型进行联合仿真，研究它对车辆系统动力学性能的影响，并进行了台架试验验证。结果表明，复合型液控径向机构不但可以保证车辆具有良好的曲线通过性能，而且可大幅度提高车辆的稳定性。

关键词: 地铁车辆, 径向转向架, 曲线通过性能, 复合型径向机构, 蛇行运动稳定性