Decoupling Optimum Design of Motor Suspension System for Metro Vehicles

The motor was considered as a rigid body with 6 degrees of freedom, the free vibration equation of the suspension system was established. Taking the decoupling degree as the optimization goal, the motor traverse and floatation frequency as the constraints, the three-dimensional stiffness of the rubber elements of the motor suspension system is optimized based on the genetic algorithm. Combined with a subway vehicle dynamics model and field tests, the vibration and stress of the bogie and car body were analyzed when the rigid suspension scheme and the decoupling optimum elastic suspending scheme were adopted. Results show that each rigid mode of the motor can obtain a good decoupling degree, the highest decoupling degree reached 100%, frequencies distribution and expected value are basically the same. Compared with the rigid suspension scheme, when the motor adopts the elastic suspension scheme with optimized decoupling, it can effectively reduce the vibration and dynamic load of the critical parts of the bogie, which effectively reduces the fatigue damage of the bogie. © 2017, Editorial Department of Journal of Tongji University. All right reserved.