Vibration Characteristic Research On The EMU Gear Transmission System

As one of the most widely used form of transmission, gear transmission has developed to the direction of high-speed and heavy load, meanwhile, vibration characteristic research on gear transmission system has become increasingly popular topic. This study relies on the National Natural Science Foundation of China and the Ministry of Railways High Speed Rail Infrastructure Research Foundation (U1234208), combined with vibration theory and finite element method, make study for the following aspects.First, establish the model of the EMU gear transmission system based on the 3D solid modeling software Solidworks and research the method to establish precise helical gear and it’s bound manner. Through the ANSYS Workbench software, the finite element model is established with simplify the model according to the actual situation and the simulation calculation requirement.Secondly, study the static characteristics of the gear transmission system. Analysis the maximum contact stress and it’s distribution form and contrast the result with the helical gear stress calculations according to the classical theory of Hertz. Find the maximum stress position of the gearbox under limit load condition, therefor, provide a theoretical basis for the box design and optimization and troubleshooting and analysis. The result showed that the maximum stress occurs at the box pinion near the bearing hole, but the overall stress level is not high, the structural strength is meet the demand.Then, study the dynamic characteristics of the gear transmission system. Modal analysis result shows that at low-frequency, vibration mainly for the large gear and gearbox shows local vibration at several frequency. Transient structural analysis shows that the stress wave is under 15% coursing by the internal incentive. Harmonic analysis on gearbox shows that the box showed obvious vibration at 630Hz frequency.Finally, study the vibration characters of the system under the extrinsic incentives. Results show that the casing vibration response increased with train speed increase, and the acceleration shows differences between the different parts of the gearbox. Along with the speed increase, vibration energy also gradually to increase high frequency area.