Structure Simulation And Fault Feature Analysis Of High-speed Train Gearbox

In recent years,China’s railway industry has developed rapidly,and high-speed railways have become one of China’s "four new inventions".The operating speed of China’s high-speed rail has reached the world’s advanced level,and gearboxes play a vital role in high-speed train operation.Once the gearbox fails,it will cause serious accidents.From the practical point of view,the following research has been carried out on the gearbox of high-speed trains:(1)According to the physical size and related parameters,building a gearbox assembly model in Solid Works;according to the Workbench analysis,the maximum stress of the box under the starting load occurs at the inner bend where the upper end of the box contacts the C-frame,and the stress value is far less than the yield strength of the box material;the maximum strain occurs at the inner bend where the lower end of the box is in contact with the C-frame,and the strain value is less than the 2%elongation required for box casting;analyzing the restraint mode of the box body,it was found that the more obvious swing at the bottom tank of the lower box body is more likely to affect the safety performance of the box body.(2)Establish a rigid-flexible coupled dynamic model of transmission system rigidity and box flexibility in ADAMS/view.The simulation results of the gear speed and meshing force in the normal gear simulation results are compared with the theoretical calculations,and the results show that the error is small,indicating that the model is more accurate;analyzing the vibration response of the box under internal excitation,it is found that the vibration displacement of the top of the upper box and near the large bearing seat is more obvious,the vibration velocity response near the upper housing pinion bearing housing and the lower housing near the large housing is relatively obvious,and the vibration acceleration near the small gear bearing seat and near the upper box observation port is more obvious.When optimizing the structure of the gearbox,the above areas should be taken into consideration.(3)Set tooth surface wears and gears broken teeth in the model to simulatereal-life faults.In MATLAB,the characteristics of the vibration signal of the box under the three conditions of normal gear,tooth surface wear and gear broken gear are analyzed,and the results show that the amplitude of the vibration signal is significantly increased when the gear is broken,and there is an impact phenomenon;in the frequency domain diagram,there are wide and high modulation sidebands near the higher harmonics,meshing frequencies and doubling frequencies of the frequency conversion.There are modulation phenomena in the detailed spectrum diagram,and peaks appear at the second harmonic.Through the research on the above content,it can provide a certain reference for the optimization of the structure of the box and the fault diagnosis of the gear,which has a guarantee significance for the safe operation of the high-speed train.