Abstract:

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 or, 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.

Key words: high speed vehicle, vibration, waviness, bearing