Integrated system of motor-transmission for pure electric vehicles generally has the feature of high power density and high-speed of the motor

small volume of the system.This means that the thermal design of the system is crucial.In order to obtain an accurate thermal field and stress simulation of the system

electromagnetic thermal fields and structural field and temperature field are expected to be calculated in a coupled simulation.Coupling model is established based on theory of multifield coupling.The multi-field coupling analysis is achieved by calculating the loss of the system and using the load transfer method with ANSYS software.The results are compared with experimental data to validate the model.