摘要
轮轨粘着曲线负斜率会导致传动系统强烈的自激扭转振动,引起轮轨粘着系数周期性的变化,从而会导致轮对纵向振动,轮对纵向振动与轮对粘滑振动耦合作用导致机车复杂的动力学行为。建立机车单轮对传动系统简化模型,考虑轮对回转及纵向自由度。通过数值仿真,再现了平均蠕滑率超过临界蠕滑率时,传动系统扭转振动及轮对纵向振动相轨迹,并计算传动系统扭转和轮对纵向振动频率,利用图解法分析纵向振动机理。结果表明,当机车打滑时,轮对纵向振动为自激振动,轮对纵向振动频率为传动系统扭转固有频率整数倍,且为两倍时振动幅值最大。因此需要合理设置轮对纵向定位刚度等参数,避免打滑时引起的轮对强烈的纵向振动。
Roll-slip oscillation in locomotive is an unstable vehicle motion and it turns into strong self-excited torsional vibration of drives and is usually associated with a negative slop of adhesion curve. The periodic variation of adhesion coefficient between wheel and rail arises and it provokes longitudinal vibration of wheel set. A simplified mathematical model of single wheel-set drive system of locomotive whose rotary and longitudinal freedoms are taken into account is established. The phase trajectory of longitudinal vibration of wheel-set is drawn by numerical simulation and frequencies of vibrations are calculated on the condition that the mean creep ratio exceeds critical creep ratio. The formed mechanics of longitudinal vibration makes clear with help of graphical analysis. Results demonstrate that the longitudinal vibration is self-excited vibration during locomotive slippage. The longitudinal vibration frequency is integral multiple of nature frequency of torsion vibration and the amplitude of longitudinal vibration is the biggest when it is two times. Therefore, parameters such as longitudinal locating stiffness of wheel set should be set rationally to avoid strong longitudinal vibration of wheel set during slippage.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第7期199-203,共5页
Journal of Mechanical Engineering
基金
国家自然科学基金(50875219)
长江学者和创新团队发展计划(IRT0452)
牵引动力国家重点实验室自由探索自主研究课题(2008TPL-T05)资助项目
关键词
机车传动系统
轮对
纵向振动
车轮滑动
Drive system of locomotive Wheel set Longitudinal vibrations Wheel slippage
