Study On The Failure Reason And Improvement Scheme Of Hanging Device Structure Of Gear Transmission System Used In The Railway Vehicle

Since the 21 st century,rapid development of rail transit in China,with the continuous increase of traffic density and train speed,which not only facilitates the life of the people,but also rail transit equipment manufacturing industry with market prospect and international competitiveness has become an advanced representative of national strategy,driving the economic vitality of all regions.Accordingly,its reliability has been put forward Strict and higher requirements.Bogie is the foundation of stable operation of train,and gear transmission system is the core component of bogie.The hanging device used to connect the bogie and the gear transmission system bears the wheel rail excitation caused by road irregularity,the dynamic force caused by vehicle body and frame vibration,the meshing excitation of gear pair in the process of power transmission and the dynamic load caused by its own factors.Under the action of the above loads alone or jointly,the hanging device is easy to shorten the service life due to fatigue damage,and becomes a hidden danger of train operation.Therefore,based on the fracture problem of the hanging device of a domestic urban rail gear transmission system in service,this paper studies the failure reasons and the improvement scheme by means of physical detection,numerical simulation and line measurement.The specific research contents are as follows:(1)This paper summarizes the research status of domestic and foreign rail vehicle gear transmission device,introduces the connection mode of several commonly used gear transmission system hanging devices,On this basis,a detailed study on the broken hanging device of a operation line is carried out,including the macroscopic and microscopic observation of the surface,the examination and analysis of the metallographic structure of the fatigue source area of the fracture,the analysis of the physical and chemical properties and the processing technology,and the preliminary failure reason is fatigue failure.(2)Establish the finite element analysis model of gear box and hanging device,determine the operation conditions,and calculate the mechanical properties.According to the results of simulation analysis and ASME viii-2 standard,the strength is checked to provide reference for structural optimization.(3)Test the dynamic stress,load and vibration acceleration of the hanging device under the actual application conditions,the dynamic stress of the gear transmission system box,and the vibration acceleration of the frame,gearbox and axle box,and evaluate the fatigue strength of the hanging device.(4)In view of the failure reason,through upgrading the material,optimizing the structure and adopting the better technology to improve the hanging device,the hanging device meeting the use requirements of complex lines is designed.(5)According to the fourth strength theory,the static strength of the improved hanging device is checked;according to the measured data of the operation line,the fatigue strength is checked by the fatigue limit method,the cumulative damage method and the test verification method respectively to ensure that the improved hanging device meets the use requirements.