An analysis of abnormal vibration and noise caused by shaft coupling misalignment of high-speed train

Abstract

This study conducts on-site testing and simulation analysis of the abnormal noise phenomenon generated during the operation of high-speed trains. The sound pressure characteristics in the cabin and the vibration of different vehicle components are recorded and subjected to comprehensive analysis. Test results indicate that significant abnormal noise occurs inside the cabin at the speed of 250 km/h, with frequencies of 87 Hz, 173 Hz, 259 Hz, and 346 Hz. Through sound source identification, vibration transmission analysis and theoretical derivation, it has been determined that the abnormal noise primarily originates from the transmission system, and it is further speculated that these abnormal vibrations and noises may be correlated with the shaft coupling misalignment within the transmission system. To verify the conjecture, a high-speed vehicle electromechanical coupling simulation model was established, incorporating the shaft coupling misalignment in the transmission system. The vibration characteristics of vehicle components were analyzed, confirming that shaft coupling misalignment leads to uneven meshing forces in gears, resulting in significant vibration and noise that affect the riding comfort of the vehicle. We propose replacing the shaft coupling to solve this problem, the test results showed that the abnormal vibration amplitudes of the transmission system at 87 Hz, 173 Hz, 259 Hz, and 346 Hz were significantly reduced after replacing the shaft coupling, and the amplitude of the corresponding frequencies on the cabin floor decreased by 91 %, 78 %, 98 %, and 66 %, respectively. The issue of abnormal noise has been effectively resolved.