作为列车走行部的关键零部件，轴箱滚动轴承支承松动故障会直接影响到车辆的运行平稳性。针对高速列车滚动轴承内圈与轴颈配合的松动问题，提出一种车体-构架-悬挂-滚动轴承-轮轨的垂向耦合动力学模型，并采用优化的四阶Runge-Kutta数值积分及试验方法，研究不同松动间隙、不同行驶速度下，高速列车滚动轴承支承松动系统的非线性动力学特性。结果表明：理论计算与试验结果较吻合，松动间隙的大小对未松动侧轴箱的振动响应影响不大，但对松动侧轴箱的振动响应有较大影响，且可使得系统的运动状态由近拟周期运动发展为混沌运动。列车低速行驶时松动侧轴箱振动幅值和振动速度均比高速行驶时更大，轴箱振动响应的低频成分只与行驶速度有关，不随松动间隙的改变而改变。

As the key part of the train bogie,the rolling bearings with pedestal looseness will directly affect the vehicle running safety and smoothness. For the problem of the high-speed train rolling bearing subjected to looseness faults on the fitting surface between inner ring and shaft neck,the vertical coupled dynamic model of high-speed train car body-frame-suspension-rolling bearing-wheel/rail is proposed. Optimized Runge-Kutta numerical integral method and experimental method is constructed to study the nonlinear dynamic characteristics of the coupled system of high-speed train rolling bearing with pedestal looseness under different loosening clearance and speeds. The result shows that the theoretical calculation fit well with experimental results,and the size of the looseness gap value has negligible effect on the vibration response of the axle box on the side without loose,but it has a great influence on the vibration response of the loose axle box. The system motion state will be changed,which the nearly quasi motion turn to chaotic motion. When the train travel at low speed,the vibration amplitude and vibration velocity of the loose axle box is greater than that of its high speed. The low frequency component of the vibration response of the axle box is only related to the speed,which doesn’t change with the change of the looseness gap value.