Affiliations: [a] Department of Electrical Engineering, Chosun University, Gwangju, Korea | [b] School of Information and Communication Engineering, Sungkyunkwan University, Suwon, Korea
Correspondence:
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Corresponding author: Yong-Jae Kim, Electrical engineering, Engineering College, Chosun University, Korea. E-mail: kimyj21@chosun.ac.kr
Abstract: A magnetic gear, which can transfer torque without contact, has many advantages over mechanical gears. These advantages include high-efficiency and high-reliability. Consequently, the magnetic gear is utilized in many different fields of study. However, because the magnetic gear uses NdFeB permanent magnets (PMs) for high power density, eddy-current loss can occur. Eddy-current loss is very problematic because it is the main factor that reduces torque transfer efficiency. Therefore, in the present study, we calculated the eddy-current loss from PMs at different rotational velocities by using a nonlinear finite element method (FEM) based on a three-dimensional numerical analysis, and analyzed how the eddy-current loss affects the torque transfer efficiency. Furthermore, we proposed a new geometry for the magnetic gear to reduce the eddy-current loss of PMs and improve the torque transfer efficiency.
Keywords: Magnetic gear, permanent magnet (PM), eddy-current loss, torque transfer efficiency, finite element method (FEM)
