【作者】 李秋泽；

【导师】 孙守光；

【作者基本信息】 北京交通大学 ， 车辆工程， 2016， 博士

【摘要】 在铁道部技术引进的四种动车组中,只有CRH5型动车组驱动系统采用体悬式结构,运营初期驱动系统暴露的故障比较多,主要表现在万向轴及其连接的齿轮箱小齿轮轴和牵引电机输出轴上。万向轴长1945mm,布置于车体和转向架间,因故障脱落后将导致车体"撑杆跳",严重影响动车组的安全运营。本文以CRH5型动车驱动系统万向轴为研究对象,从驱动系统的布置、万向轴运动特性、万向轴结构和制造等方面分析了万向轴失效的机理,提出了驱动系统和万向轴的结构优化方案,经实际线路测试、数据对比分析,验证了驱动系统的优化方案和新结构万向轴是可行的,主要内容如下:(1)统计和梳理了 CRH5型动车组驱动系统、万向轴在运用和检修中发生的典型故障,建立了驱动系统故障树,采用故障模式影响及危害性分析(FMECA)法重点分析了万向轴的典型故障。(2)研究双十字轴式万向轴运动特性,分析万向轴Z-W型布置时的附加力矩、附加载荷及轴的波动率,建立了 CRH5型动车驱动系统运动分析简图,计算万向轴空间运行姿态极限位置及相应位置时附加力矩和附加惯性力矩。(3)采用SIMPACK多体系统仿真软件,考虑齿轮箱组成及牵引电机的悬挂结构,建立带有万向轴驱动系统的CRH5型动车组车辆动力学模型,考虑万向轴驱动系统与车辆振动系统的耦合,分析驱动系统对动车组非线性稳定性的影响;分析列车在直线和曲线工况下万向轴回转力矩、角速度及角加速度、牵引电机的位移及加速度;分析驱动系统振动频率的变化和转动惯量变化对驱动系统动力学性能的影响。经动力学对比得知:驱动系统传动比由2,5改为2.22,降低系统转速,可使万向轴附加力矩、转角加速度降低8%-11.2%;驱动系统布置角度由4.41°降为2.91°,可使万向轴附加力矩、转角加速度降低2%-3%。(4)利用ANSYS软件建立CRH5型动车驱动系统的刚柔耦合模态分析模型,通过齿轮箱和牵引电机的响应分析确定万向轴的一阶弯曲频率为89.34Hz,万向轴对应的临界转速为5360rpm;对万向轴驱动系统进行台架测试,万向轴在系统中的自振频率为74Hz,对应的临界转速为4440rpm;采用传统公式计算得到的万向轴临界转速为5610rpm。对比分析可知:万向轴在驱动系统中临界转速为有限元分析法计算临界转速的82%左右,为传统公式计算临界转速的79%。(5)通过对万向轴本身结构研究得出其失效的主要影响因素:1)万向轴的动不平衡限值,通过试验证明减小动不平衡值,万向轴两端的振动幅值降低,可减小万向轴失效概率;2)滚针轴承是万向轴的薄弱环节,在结构设计时应考虑轴承衬套和滚针的接触压应力变化;3)万向轴在设计和制造时应重视润滑与密封的设计。(6)采用多目标函数优化法,确定了 CRH5型动车组万向轴驱动系统优化方案:1)优化万向轴驱动系统布置角度,由4.41°改为2.91°;2)优化万向轴驱动系统传动比,由2.5改为2.22;3)优化驱动系统悬挂件刚度;4)采用新结构万向轴,经线路测试数据对比和万向轴分解检查分析,验证万向轴驱动系统优化方案切实可行。更多还原

【Abstract】 In recent years,the Ministry of Railway imported four kinds of electric multiple units(EMU),of them only CRH5 used the body suspension structure for its drive system.During the initial stage of operation,this structure exposed a few problems and mainly expressed by the universal shaft,the gear box pinion shaft connected with it and the traction motor output shaft.The universal shaft’s length is 1945mm.It was fixed between the car body and the bogie.The falling off of the universal shaft will result in "pole vault"of the car body,which seriously affected the safety of train operation.This thesis takes CRH5 drive system universal shaft as research object,analyses the failure mechanism of universal shaft from different angles,and puts forward the optimization plan for universal shaft and drive system.The actual circuit test and the data from the test proved that the optimized plan is available.The main contents of this thesis are as follows:(1)The typical faults of drive system and universal shaft are calculated and analysed.The fault tree of drive system is constructed.The typical faults of universal shaft are emphatically analysed by FMECA method.(2)The movement characteristics of double cross universal shaft are studied.The additional load,additional moment and volatility of shaft are analysed when the universal shaft is decorated at Z-W type.A movement analysis diagram of CRH5 drive system is built up.The limit position of universal shaft and the additional moment,additional inertia moment at corresponding positions are calculated.(3)A dynamic model of CRH5 drive system is simulated by SIMPACK according to the structure of gear box and the suspension mode of traction motor.The influence caused by drive system on EMU nonlinear stability is analysed.The gyroscopic moment,angle velocity and angular acceleration of drive system and the displacement and acceleration of traction motor when the train is at straight and curve conditions are analysed.The influence on the drive system caused by the change of vibration frequency and inertia moment of drive system is analysed.According to the analysis above,we get that by changing the drive system ratio from 2.5 to 2.2 and reducing the revolving speed,the additional moment and rotating angular acceleration of universal shaft could be reduced by 8%-11.2%.By adjusting the arrangement angle of the drive system from 4.41° to 2.91°,the additional moment and rotating angular acceleration of universal shaft could be reduced by 2%-3%.(4)A rigid-flexible coupling modal analysis model of CRH5 drive system is established by ANSYS.The critical rotational speed of universal shaft corresponding to its first-order bending frequency is 5360rpm while the frequency is 89.34Hz.According to the engine bench test,the natural frequency of universal shaft in the drive system is 74Hz and the corresponding critical rotational speed is 4440rpm.We also can get a critical rotational speed 5610rpm according to the traditional formula.Based on the comparative analysis,we deduce that the critical rotional speed of universal shaft got by the bench test is about 82%of the speed calculated by finite element method and 79%of the speed calculated by traditional formula.(5)The influence factors of universal shaft failure caused by its structure are analysed:1)It was demonstrated that the vibration amplitude of ends of universal shaft can be reduced by decreasing the dynamic-unbalance value,which could decrease the failure probability of universal shaft.2)The needle roller bearing is the weak link of universal shaft,therefore,the compressive stress between the bearing bush and the needle roller should be considered while doing structure design.3)Design of lubrication and sealing needs to be emphasized while designing and manufacturing the universal shaft.(6)The optimization plan of CRH5 universal shaft drive system are put forward by multi-objective function optimization method:1)Adjust the arrangement angle of the drive system from 4.41° to 2.91°;2)Change the drive system ratio from 2.5 to 2.2;3)Optimize the stiffness of the suspention parts of the drive system;4)Use a new structural universal shaft.The data gathered by actual circuit test and analysis of the universal shaft proved that the optimized plan is available.更多还原