Test study on vibration behavior and bearing load characteristics of high-speed train gearbox under internal excitation

Internal excitation is an important factor affecting vibration of gearbox and dynamic load of gearbox bearing of high-speed train. Here, with the help of a gearbox transmission system test bench, tests of gearbox body vibration response and gearbox bearing load testing of high-speed train were conducted under working conditions of various torques and rotating speeds. By analyzing vibration signals of different parts and positions of gearbox under various working conditions, it was shown that the gear meshing frequency at a specific rotating speed can stimulate modal resonance of gearbox body, while torque can affect frequency response characteristics of the system. The order tracking for gearbox vibration acceleration under accelerating working conditions was performed, and modal parameters of gearbox body were obtained by using the order-based operational modal identification method, it was shown that operational modal shapes of gearbox cause differences of vibration behaviors of gearbox at different rotating speeds; by comparing RMSs of gearbox vibration accelerations and measured bearing load variation coefficients under different working conditions, corresponding relations between gearbox bearing load dynamic characteristics and gearbox vibration behaviors are established. © 2023 Chinese Vibration Engineering Society. All rights reserved.