The Vibration Isolation Design Of EMU Carbody And Traction Transformer Device

Design of train structure is developing to the trend of light weight,which often makes the weight ratio of the equipment under the train larger,especially the active equipment intensifying the vibration from itself.In this paper,traction transformer on high speed train hung i'n the bottom of the train body through six vibration isolator connected to the hanger.They made up traction transformer isolation system together.Research on the vibration isolation performance of the system is very necessary,because that performance of vibration isolation will directly affect the safety and comfort of motor train unit.In chapter 1,the research achievements and present situation about the vibration and vibration isolation of traction transformer were discussed in detail,the current traction transforner isolation method was analyzed,and the significance and research direction of traction transformer vibration isolation design was clearly identified.In chapter 2,vibration isolation system model was established.First,the motion differential equations of traction transformer isolation system were established and the expression about the force transfer rate of vibration isolator in vibration isolation system were derived.That realized in Matlab by encoding and in ADAMS by establishing corresponding physical models,in which vibration characteristics of different platform models were compared and the results validated the effectiveness of the model.In chapter 3,the range of total vertical stiffness was given based on principle of static deflection matching and frequency matching of SDOF and MDOF.Calculated conditions on both the suspension stiffness of traction transformer and multiple sets in vibration isolation system which could meet the requirements of the project were made.Second,the finite element model of car body-traction transformer was set up and modal analysis was carried out.The analysis of modal data contrast shows that the results of simulation calculation of the model meet the conditions of the engineering application.In chapter 4,through the simulation calculation and analysis about intensity of the train oscillation and transmissibility of force,comparative analysis among three aspects were analyzed respectively:influence from the change of the different stiffness distribution schemes in vibration isolation system to traction transformer vibration,influence from total suspension stiffness to vibration in the start process of draught fan on the traction transformer,influence from total suspension stiffness to vibration in status of half or full turn work condition of draught fan.The phenomenon was found that intensity of oscillation is only connected with the suspension stiffness of traction transformer,and has nothing to do with different stiffness distribution schemes in vibration isolation system.The intensity of oscillation got minimum when the suspension stiffness value was 7.5 MN/m.Different stiffness distribution schemes had little influence on transmissibility of total force,by calculating the summation of the transmissibility of force from the three groups,the total transmissibility of force got minimum when the suspension stiffness value was between 7.35 MN/m?7.50 MN/m.As a consequence,in the premise that synthesized intensity of oscillation and transmissibility of force,traction transformer isolation system will have a better effect if the suspension stiffness value was designed between 7.35 MN/m?7.50 MN/m.Finally,main content of this paper was summarized and the research conclusion was draw after which reasonable suggestions were put forward to the in-depth study of this topic in the future.