Vibration Isolation Design and Test Research of Powerpack for Hybrid Electric Multiple Units
The powerpack which is suspended under the car body of the EMU generates an exciting force with large amplitude and complex frequency during operation.It will affect its own operation and cause the running comfort and safety problems of the car body.Therefore,the Powerpack needs to be vibration-isolated.A dynamic model of double-layer vibration isolation system with multi substructure is established.According to the Monte Carlo sensitivity method,the design variables are selected.The vibration isolation efficiency of the system is used as a constraint condition.The vibration intensity of the diesel generator set and the dynamic reaction force transmitted to the car body are taken as the optimization objectives.Then,the enumeration method is used to optimize the dynamic stiffness of the vibration isolation system.In order to verify the rationality of design dynamic stiffness,the ADAMS rigid-flexible coupling model of the package is established.Finally,the vibration intensity and vibration isolation efficiency tests are carried out.The test results show that the vibration intensity of the diesel generator set is less than 18mm/s,and the vibration isolation efficiency of the vibration isolation system is more than 85%at different rotary speed.It means that the vibration isolation design method can be effectively applied to the vibration isolation design of a double-layer vibration isolation system with multiple substructures.