Research Of The Fault Diagnosis For CRH5EMU Train Transmission System

Rail transportation gradually been recognized by people owing to the convenience and environmental, and it is widely used all over the world. CRH5is a new type emu train designed and manufactured in China after introducing the foreign leading technology on high sped train. Its electric machine is hanged under the train body, the electric machine transmit the driving force by cardan shaft. When the dynamic unbalance of the cardan shaft is overweight, it will be high-speed rotating eccentricitily, the cross cardan bear on the both ends will severe wear, which leads to the cardan shaft and gear box failure, then weaken the security of the transport. So focusing on the fault diagnosis of the transmission system has the practical significance.This thesis introduce the CRH5emu train drive system, its failure mode, test scheme and the time-frequency characteristics of the vibration signals, Then formulate the total fault diagnosis scheme include vehicle module and background analysis module. The following characteristic parameters are used in this vehicle module:RMS combined with kurtosis in time domain, Le’s frequency and mean frequency in frequency domain. Background fault diagnosis mainly uses the EMD method, using the Hilbert-Huang to calculate the average instantaneous amplitude and the time-frequency entropy of Hilbert spectrum, establish long-term health monitoring database. Through the comparison of data, we can master the state of the transmission system and the trend of fault, and also, it can be useful for designing the structure of the transmission system and formulate the maintenance cycle in the future. This thesis used the simulation, bench test and the line test to verify the effectiveness of the EMD method, and it proved that these characteristic parameters are sensitive to the dynamic unbalance of cardan shaft. Research shows that the scheme can diagnosis the fault of the CRH5emu train transmission effectively.