In coaxial magnetic gear (CMG), magnetic modul ation ring is composed of a modulator and a connecting bridge. The torque performance of the magnetic gear are affected by the different structures of the magnetic modulation ring. In this paper, fifteen different kinds of magnetic modulation rings with different structures are proposed; they consist of three different shapes of modulators and five different locations of connection bridges. By using the two-dimensional finite element method (FEM), the magnetic flux density, magnetic line distribution, static torque, and steady-state torque of the CMG with different structures of magnetic modulation ring are analyzed. The results show that the innermost bridge has the least effect on the torque and torque ripple of the CMG, while the outermost bridge has the opposite effect. The torque capacity of the circular modulator and arc modulator is higher than that of the square modulator, and the circular modulator helps to reduce the inner torque ripple, while the square modulator helps to reduce the outer torque ripple. This paper can provide some references for the design of the magnetic modulation ring.
2. Tsurumoto, K. and S. Kikuchi, "A new magnetic gear using permanent magnet," IEEE T. Magn., Vol. 23, No. 5, 3622-3624, 1987.
3. Yao, Y. D., D. R. Huang, S. M. Lin, and S. J. Wang, "Theoretical computations of the magnetic coupling between magnetic gears," IEEE T. Magn., Vol. 32, No. 3, 710-713, 1996.
4. Filippini, M. and P. Alotto, "Coaxial magnetic gear design and optimization," IEEE T. Ind. Electron., Vol. 64, No. 12, 9934-9942, 2017.
5. Tsai, M. and C. Huang, "Development of a variable-inertia device with a magnetic planetary gearbox," IEEE/ASME Transactions on Mechatronics, Vol. 16, No. 6, 1120-1128, 2011.
6. Gerber, S. and R. Wang, "Design and evaluation of a magnetically geared PM machine," IEEE T. Magn., Vol. 51, No. 8, 1-10, 2015.
7. Zhu, X., L. Chen, L. Quan, Y. Sun, W. Hua, and Z. Wang, "A new magnetic-planetary-geared permanent magnet brushless machine for hybrid electric vehicle," IEEE T. Magn., Vol. 48, No. 11, 4642-4645, 2012.
8. Jing, L., T. Zhang, Y. Gao, R. Qu, Y. Huang, and T. Ben, "A novel HTS modulated coaxial magnetic gear with eccentric structure and halbach arrays," IEEE T. Appl. Supercon., Vol. 29, No. 5, 1-5, 2019.
9. Rasmussen, P. O., T. O. Andersen, F. T. Jorgensen, and O. Nielsen, "Development of a high-performance magnetic gear," IEEE T. Ind. Appl., Vol. 41, No. 3, 764-770, 2005.
10. Uppalapati, K. K., M. D. Calvin, J. D. Wright, J. Pitchard, W. B. Williams, and J. Z. Bird, "A magnetic gearbox with an active region torque density of 239N·m/L," IEEE T. Ind. Appl., Vol. 54, No. 2, 1331-1338, 2018.
11. Dragan, R. S., R. E. Clark, E. K. Hussain, K. Atallah, and M. Odavic, "Magnetically geared pseudo direct drive for safety critical applications," IEEE T. Ind. Appl., Vol. 55, No. 2, 1239-1249, 2019.
12. Iwasaki, N., M. Kitamura, and Y. Enomoto, "Optimal design of permanent magnet motor with magnetic gear and prototype verification," Electr. Eng. Jpn., Vol. 194, No. 1, 60-69, 2016.
13. Peng, S., W. N. Fu, and S. L. Ho, "A novel high torque-density triple-permanent-magnet-excited magnetic gear," IEEE T. Magn., Vol. 50, No. 11, 1-4, 2014.
14. Wang, R. and S. Gerber, "Magnetically geared wind generator technologies: Opportunities and challenges," Appl. Energ., Vol. 136, 817-826, 2014.
15. Zhu, X., L. Chen, L. Quan, Y. Sun, W. Hua, and Z. Wang, "A new magnetic-planetary-geared permanent magnet brushless machine for hybrid electric vehicle," IEEE T. Magn., Vol. 48, No. 11, 4642-4645, 2012.
16. Liu, X., Y. Zhao, Z. Chen, D. Luo, and S. Huang, "Multi-objective robust optimization for a dual-flux-modulator coaxial magnetic gear," IEEE T. Magn., Vol. 55, No. 7, 1-8, 2019.
17. Wang, Y., M. Filippini, N. Bianchi, and P. Alotto, "A review on magnetic gears: Topologies, computational models, and design aspects," IEEE T. Ind. Appl., Vol. 55, No. 5, 4557-4566, 2019.
18. Li, X., M. Cheng, and Y. Wang, "Analysis, design and experimental verification of a coaxial magnetic gear using stationary permanent-magnet ring," IET Electr. Power App., Vol. 12, No. 2, 231-238, 2018.
19. Kim, S. J., E. Park, S. Jung, and Y. Kim, "Transfer torque performance comparison in coaxial magnetic gears with different flux-modulator shapes," IEEE T. Magn., Vol. 53, No. 6, 1-4, 2017.
20. Abdelhamid, D. Z. and A. M. Knight, "The effect of modulating ring design on magnetic gear torque," IEEE T. Magn., Vol. 53, No. 11, 1-4, 2017.
21. Zhang, X., X. Liu, and Z. Chen, "A novel dual-flux-modulator coaxial magnetic gear for high torque capability," IEEE T. Energy Conver., Vol. 33, No. 2, 682-691, 2018.
22. Jian, L., Z. Deng, Y. Shi, J. Wei, and C. C. Chan, "The mechanism how coaxial magnetic gear transmits magnetic torques between its two rotors: Detailed analysis of torque distribution on modulating ring," IEEE/ASME Transactions on Mechatronics, Vol. 24, No. 2, 763-773, 2019.
23. Amrhein, M. and P. T. Krein, "Force calculation in 3-D magnetic equivalent circuit networks with a Maxwell stress tensor," IEEE T. Energy Conver., Vol. 24, No. 3, 587-593, 2009.