Elastic Wave Suppression of Permanent Magnetic Motors by Pole/Slot Combination

Abstract

This work investigates the influence of the pole/slot combination on the elastic wave deformation of permanent magnetic motors. To this aim, the local wave superposition and distributed wave interaction methods are used during investigation. The methods borrow ideas from other fields such as the planetary gears, the turbines, and so on because of the inherent mechanical and magnetic symmetry of the motor. More precisely, the symmetry naturally presents some interesting and useful results without specifying the magnetic pulls/waves or even their magnitudes. The analysis results explicitly show that the elastic wave deformations only depend on whether particular algebraic relations are satisfied by the combination of pole number, slot number, magnetic pull order, and wave number. The predicted relationship and the wave suppression effectiveness are verified by the finite element method and a comparison with an existing literature. The relationship naturally provides simple guidelines for the elastic wave deformation suppression only by using the proper pole/slot combination.

Magnetically induced rotor vibration in dual-stator permanent magnet motors

“…It needs to be noted that some of these results, especially the rigid and elastic vibration for n¼ 0 and 71, are scattered in the literature, such as a recent paper [35]. Whether they are excited or not depends on the forcing terms on the right hand side, like those in motor, gear and other cyclically symmetric power-transmission systems [11,12,14,24,27]. …”

“…In this sense, the analytical results agree well with those by using concentrated force in Refs. [11,12,14].…”

“…Given the structural and force complexes, the scope is limited to the lower speed motors such as the direct drive one. Main findings are obtained by analytical derivation and verified by comparison with those from superposition method [12,14] and FEM. Fig.…”

“…Since the motors are characterized as symmetric topology with moving loads [29], one can make full use of the symmetry to help capture vibration nature. Motivated by the similarities between power-transmission systems [23][24][25][26][31][32][33], authors of this work proposed superposition and modulation methods to deal with the typical rigid-elastic vibrations of conventional motors [11,12]. Also authors employed the superposition method to address the typical vibration by incorporating cyclic symmetry [27].…”

Analytical Treatment With Rigid-Elastic Vibration of Permanent Magnet Motors With Expanding Application to Cyclically Symmetric Power-Transmission Systems

“…Chen et al [13] utilized an elastic shell to simulate a slotted stator and obtained the relationships between a slot/magnet combination and dominant vibration. Based on mechanical and magnetic symmetries, the authors of this work investigated the relationships using the superposition treatment [14]. Jang and Lieu [15] employed the finite element method to deal with the stator's response with an aim to examine the vibration source and its transmission through the stator to the surrounding system.…”