Load data calculation in electric axle drives and fatigue assessment for the electric motor subsystem

In the present work, a fatigue assessment of the electric motor within the electric axle drive (electric axle) was developed using virtual load data. Now that the electric axle with torque vectoring function has been integrated into multiple vehicle classes, it is possible to create simulation models which allow the drive train to be mapped in various driving scenarios. Validation is performed by means of optical measurement methods (object tracking) which allow to determine load data for subsystems and components under variable torque and speed scenarios (e.g., handling course). In this paper, a load spectrum was created and used for fatigue analysis of the subsystem, namely the traction motor (EM) and torque vectoring motor. Based on the local stress, a finite element analysis (FEA) was carried out on the rotor, and investigations of strength and fatigue were performed on thin sheets of electrical steel. These S-N diagrams consider various factors such as material, temperature, and influence of specimen dimensions and are the basis for fatigue assessment based on the load spectrum from simulation.