Analysis and determination of mechanical bearing load caused by unbalanced magnetic pull

One common mechanical fault in electrical drives applied to industrial processes are related to bearing damage [1]. These faults can be brought forward by mechanical and thermal stress during the operation. This paper focuses on the radial electromagnetic forces, which are known as static and dynamic unbalanced magnetic pull (UMP), caused by rotor eccentricities. In particular in this paper the interaction of the rotor position and the amplitude of the static and dynamic eccentricity, the slot harmonics and saturation effects in the entire operational range of a permanent magnet synchronous machine (PMSM) are studied.