Strength Simulation And Test Research Of High Speed EMU New Design Gearbox Housing

The gearbox of highspeed EMU bogie,the key load-bearing rotationunit,is used as the main traction and braking load transfer unit of the whole vehicle,itsapplication reliability strongly affects the safety of the whole vehicle operation and the passengers'lives ortheir properties.Considering the present applicaion shortages on present four importedgearboxes platforms of EMU,i.e.,the obvious differences on the technical parameters and structural dimensions,complex structures,terrible environment operation conditions,damages on the gearbox housing crack or failure of de bears or the emulsification of the oil and the oil leakage during long-term service operation,it is necessary to study or develop the new gearbox for Chinese Standard EMU on structural design,strength simulation,real gearbox bench testing and real vehicle operation testing as follows.Firstly,comparing the falure causes of the existing highspeed EMU.The failure case of gearbox is analyzed by metallographic analysis,strength mode simulation and dynamic stress test,and the causes of failure are analyzed from the aspects of structure design,manufacturing,quality control and operation environment.The strength of the gearbox housing,the vibration characteristics of the gearbox and the research status of aluminum alloy casting process are briefly introduced.Secondly,designing and structural strength or modal simulating on new gearbox.According to the requirement of highspeed EMU gearbox,the structure of the gearbox is optimizedby CATIA software,and joggles betweengearbox housingand frame,axle,coupling are researched,and focused on boommounting seat,oil level window,observation hole and other parts of the detailed structure.Furthermore,using Hyper Mesh software to optimize the boom mounting seat and oil level window.In addition,ANSYS finite element method is used to analyze the static strength and fatigue strength of the gearbox,in order to ensure the safety and reliability of the structural strength of the box.By means of modal simulation analysis,the natural vibration characteristics are mastered.Thirdly,studying on real gearbox bench testing at static strength and vibration modof the new type gearbox.On the experimental platform,the strength of the gearbox is verified through the short circuit torque test of the new gearbox housingand the stress test on the important parts.Next,in order to study its vibration characteristics,the modal frequencies of the gearbox are tested under the freestate.Lastly,studying on real vehicle operation tests at strength and vibration characteristics.Based on the finite element analysis and experimental results,a new type of dynamic stress test scheme is developed.Though the key point arrangement of strain gauges on gearbox housing and acceleration sensor on wheel set,gearbox,frame,the time and frequency characteristics of the test data are analyzed.At last,the service life of the box is evaluated,through the verification of the strength and vibration characteristics of the new gearbox.The above research efferts is of great significance on self-reliance and self-renovation gearbox for Chinese Standard EMU development.