Calculation and Analysis of Motor Mechanical Stress for In-wheel Electric Vehicle Applications

The study of mechanical stress is of great significance for the improvement of reliability and durability of in wheel motor (IWM) in service. In the present research, there are still some problems, such as incomplete consideration of mechanical load, analysis out of the actual vehicle working condition (VWC), and isolation study of single component. Aiming at the problems, this paper takes a 15kW IWM as the research object. The mechanical loads such as vibration load from random road surface excitation (RSE), electromagnetic force, torque and centrifugal force are analyzed and determined firstly. Then, a coupling analysis model of electromagnetic field and structure field suitable for the mechanical stress analysis of the whole IWM is developed. And the effectiveness of the model is verified by experiments. Finally, the established model is used to quantitatively calculate and analyze the stress state of the IWM under different VWC, and to obtain the influence law of VWC on the mechanical stress of each IWM component. What’s more, this paper also studies the stress state of IWM under the action of various mechanical loads alone and together, and finds out the main inducing factors of mechanical stress of each component of the IWM.