Natural frequencies analytical modeling of small industrial radial flux permanent magnet motors

This paper addresses the accuracy of most encountered analytical models used for the determination of stator natural frequencies, for specific small industrial radial flux permanent magnet motors. External diameters are in the range of 30 to 90 mm. Two particularly different stators are investigated using ring and cylindrical shells analytical theories. Results are compared to finite elements and then validated thanks to measurements. Height of teeth and housing made of bearing shields (flange-mounted motor) without outer cylindrical frame are responsible for loss of accuracy between calculated and measured values.