城轨列车齿轮系统变速载工况扭振特性

Dynamic Characteristics of Torsional Vibration of Urban Rail Vehicle Gear System Under the Condition During Variable Speed Process

城轨列车实际运行工况是变速载的,传统的定常转速齿轮研究不能满足动态特性分析的需要。为此,提出一种新的时变速载齿轮系统动态特性研究方法。综合考虑时变啮合刚度、时变外部激励、静态传递误差、随机位移激励以及非线性侧隙的影响,建立城轨列车时变速载齿轮系统扭振模型。通过分析直齿轮啮合过程,修正齿轮啮合频率计算公式。基于微元法思想,计算城轨列车惰行工况、牵引工况和制动工况的速度、转速以及转角,得到时变啮合刚度的变化规律。研究结果揭示牵引工况的齿轮扭振运动在这三种运行工况中的扭振功率密度最低。在惰行工况下,齿轮系统低速运行呈现分频的现象,高速运行有陷入混沌运动的趋势;在牵引工况下,齿轮系统随转速的提高稳定性有所下降;在制动工况下,齿轮系统的扭振不显示含啮合频率的影响。

Urban rail vehicle works under the conditions of the variable speed, and the traditional method of gear system under constant speed condition cannot meet the needs of the dynamic characteristics analysis. Therefore, a new method of gear system under the time-varying load and speed condition is proposed to investigate the dynamic characteristics. Considering the influences of the time-varying mesh stiffness, time-varying external excitation, the static transmission error, random displacement excitation and nonlinear backlash, the torsional vibration model of the gear system is established. The calculation formula of gear meshing frequency is corrected by analyzing the meshing process of spur gears. Based on the cumulative integral method, the velocity, the rotational speed and the angle of the shaft are calculated for the conditions of the coasting, traction and braking, respectively. The results reveal that the power density of the gear torsional vibration in the traction condition is the lowest among the three working conditions. Under the coasting condition, the gear system presents fractional frequency phenomenon at low speed, and it has a trend of turning into chaos at high speed; under the traction condition, the stability of the gear system is decreased with the rotational speed; under the braking condition, the torsional vibration of the gear system does not show the influence of the meshing frequency.