Research On Wheelset Rolling Radius Difference Maintenance Limits Of CRH2High-speed Train Bogie

The EMU maintenance always been an important part of the railway transport work. In China, the framework of EMU maintenance system as "Planned Preventive Maintenance". Therefore, components overhaul timing is determined based on the maintenance limit. Scientific and rational maintenance limits can not only guarantee the EMU in good technical condition, but also save costs. The paper focuses on the key component of EMU——wheelset, to study the most common failure——rolling radius difference. Combined with wheel wear, optimized the maintenance limit and wheels lathing cycle of existing repair procedures. The specific work done as follows:1. Taking8wheels in same compartment as the research object, the paper introduces the root cause of wheel diameter difference, the basic form of the distribution and international research on it.2. In the depot of Beijing Railway Bureau, collected wheel wear profile data, analysis and fitted. Trace test with two kinds of vehicle, got wheel diameter data for statistical analysis.3. By means of multi-body dynamics software SIMPACK, established CRH2dynamic model. Through the dynamic simulation calculation, studying on the wheel diameter difference impact on vehicle stability, stable, security of curve passing and wheel/rail wear. Get the critical state of its existence.4. Based on the service limit, put forward a more scientific, reasonable middle repair limit(including wheel assembly and one, two or three level maintenance). At the same time, transform the parameters as wheel profile, rail lines and rail excitation, to analysis the safety. Results verify that the recommended value can guarantee the vehicle operating condition. At the same time, extend the wheel life, has the economic efficiency and the feasibility of great.5. On this basis, according to the the vehicle dynamics performance of different operation mileage with wheel diameter difference and wheel flange wear exist together, studying on the lathing cycle.The paper is combined with practical application data, proposed more reasonable maintenance limit, discussed the feasibility of extending the lathing cycle. The research content of this paper to extend the wheel life, reduce repair costs has the important meaning. At the same time, to further improve the CRH2maintenance has a certain reference value.