Impact of magnet shape and material on the magnet stress

• Published in: IET electric power applications Vol. 18; no. 7; pp. 813 - 825
• Main Authors: Cao, Li, Hu, Yan, Wang, Bohan, Wu, Wenkun, Shi, Daolong, Zhuo, Liang
• Format: Journal Article
• Language: English
• Published: Wiley 01.07.2024
• Subjects: permanent magnets; rotors; stress analysis
• ISSN: 1751-8660; 1751-8679
• DOI: 10.1049/elp2.12434

Magnet cracking is a common issue in external rotor motors. To investigate the causes of magnet cracking and propose solutions, the authors consider the effects of magnet shape, magnet and yoke material fit on the motor rotor magnets, perform a static analysis of the motor rotor. The simulation and test results show that the stress distribution of tile‐shaped magnets is better than that of rectangular magnets. The highest safety margin of 56.41% is achieved for the magnet and yoke material fit of DT4/N35(EH). The maximum force of the permanent magnet (PM) exceeds 22.38% of the stress limit when the material fit is DT4/SmCo28, which can lead to cracks in the PM. The results of this paper have important reference significance for the structural design of the external rotor motor and their safe and reliable operation. In order to investigate the causes of magnet cracking and propose solutions, the authors consider the effects of magnet shape, magnet and yoke material fit on the motor rotor magnets and perform a static analysis of the motor rotor. The simulation and test results show that the stress distribution of the magnets with tile‐shaped magnets is better than that of rectangular magnets. The highest safety margin of 56.41% is achieved for the magnet and yoke material fit of DT4/N35(EH). The maximum force of the permanent magnet exceeds by 22.38% of the stress limit when the material fit is DT4/SmCo28, which can lead to cracks in the permanent magnet. The results of this paper have important reference significance for the structural design of the external rotor motor and the safe and reliable operation of the motor.