考虑轴箱轴承表面波纹度的高速车辆振动特性分析

采用SIMPACK动力学软件,建立一高速车辆出现轴箱轴承表面波纹度缺陷的动力学计算模型,将轴承假设为只有外圈和内圈两者之间的相互作用,轴承中的滚子直接等效成若干个力元,分别考虑轴承的内、外圈以及滚子表面波纹度对车辆振动特性的影响。仿真结果表明:当轴承出现波纹度缺陷时,轴箱振动加速度会增大,而构架的加速度变化不大;对于外圈表面波纹度,会在特定频率及其倍频处出现峰值,且当纹度波数等于或接近滚子数目相或其倍数关系时,轴箱会出现严重的振动;对于内圈表面波纹度,当波纹度数N_w≠iZ±1且N_w≠iZ±1(其中i为正整数)时,在所仿真的波数下可能会出现多种基频及其倍频成分,否则只会产生特定的基频及其倍频成分;对于滚子表面波纹度,当滚子波纹度数目为偶数时,只会出现特定的基频及其倍频成分,且在特征频率旁边存在着调制边带;随着滚子波纹度数目的变化,三种情况下的轴箱振动加速度幅值会在波纹度数目等于滚子数目处产生峰值点,且随着波纹度幅值的增加,三种情况下的轴箱的振动均变得越来越剧烈。

Vibration Performance of High-speed Vehicles under Axle Box Bearing Surface Waviness

A computational model for a high speed vehicle with surface waviness in axle box roller bearings is established using the dynamic package SIMPACK. It is assumed that there only existed interactions between the outer ring and inner ring for the bearing, so that the bearing rollers are directly equivalent as several force elements. Then,the waviness located on the inner and outer rings and roller surfaces are considered and their influences on the vertical vibrations of the vehicle system are analyzed. The simulation results show that the axle box bearing surface waviness can increase the axle box acceleration, but has little effect on the bogie frame acceleration. When the waviness is located on the outer ring surface, the peak amplitude of vibration appears at a particular frequency and its multiple frequency. And the sever vibrations occurs when the number of balls and waves are equal or nearly equal. When the waviness is located on the inner ring surface, for the number of waves is not equal iZ?1 or iZ , the peak amplitude of vibration appears at many particular frequencies and its multiple frequencies, otherwise the peak amplitude of vibration appears at a particular frequency and its multiple frequency. When the waviness is located on the roller surface and the number of wave is even, the peak amplitude of vibration appears at a particular frequency and its multiple frequency with a sideband . As the number of wave change , the axle box acceleration amplitude will appears peak value when the number of waviness is equal to the number of rollers under the three cases, and with the increase of waviness amplitude, the vibration of the axle box also become more and more intense.