Influence of the symmetric structure of a wheel hub drive on the vibro-acoustic behaviour of electric vehicles due to magnetic forces

Magnetic forces in electrical machines cause vibrations on the structure and its connected components. This leads to undesired noise and vibration in the total system. This paper deals with explanation and reduction of alternating force generation at the connection point of a motor due to radial forces acting on the stator teeth with an electric wheel hub drive being used as example. These alternating forces have a disturbing effect on the driver in the form of noise or vibrations. In our research, we developed a multi-physical simulation of the system which is compared with an operational vibration analysis from an experiment. The simulation shows that the main cause is the axially asymmetric structure of the housing. We reduced the alternating forces at the connection point by using an axially symmetric structure. An axially symmetric design also of other electric machines is to be expected to significantly improve the vibro-acoustic behaviour.