Calculation and Analysis for Multidimensional Natural Frequencies of Cylindrical Motors Based on Precise Analytical Model Considering Distinct Additional Ribs and Anisotropic Material Parameters

The rapid and accurate calculation of stator natural frequencies is a principal foundation for electromagnetic vibration prediction, analysis, and suppression. In response to the shortcomings of existing calculation methods for stator multidimensional natural frequencies that cannot give attention to both rapidity and accuracy, a general and precise analytical model for stator multidimensional natural frequencies of cylindrical motors based on reasonable equivalent models of stators and accurate equivalent method for anisotropic material parameters is established, and the stator multidimensional natural frequencies under different boundary conditions, and dimensional and material parameters are quickly obtained. In addition, the detailed finite element simulation and prototype testing are performed to verify the proposed analytical method (AM) for multidimensional natural frequencies of different types of stator cores and casings, and the comparison shows that the proposed AM has high accuracy and universality for both axially and circumferentially slotted stator cores and casings with longitudinal and ring heat dissipation ribs. Finally, the variation laws of stator multidimensional natural frequencies under different boundary conditions, and dimensional and material parameters are explored and summarized, the analysis reveals that the multidimensional natural frequencies of axially slotted stator cores can be adjusted by changing the yoke average radius and thickness, and those of circumferentially slotted stator cores are sensitive to not only yoke average radius and thickness but also the number and height of teeth, which lays the foundation for adjusting the multidimensional natural frequencies of cylindrical motors and suppressing electromagnetic vibrations.