Finite Element Analysis of SMC Core Magnetic Gear for Vehicle Powertrain Systems

Abstract

The utilization of gears as intermediary components for power transmission in electric drive systems addresses the insufficiency of electric machines in handling torque loads effectively. Gears, commonly employed in the industry, can be either mechanical or magnetic, allowing for the balanced transfer of torque and speed at specified ratios. The mechanical and electrical actuation of in-vehicle accessories persists both in traditional and next-generation vehicles. Particularly concerning safety and the sustainability of spare part production and supply, various electrical accessories continue to operate at the 12 V level in modern vehicles. In this context, the use of the Lundell alternator (claw pole) also continues in next-generation vehicles. While the mechanical accessories are driven by a belt-pulley system connected to an internal combustion engine in conventional vehicles, in next-generation vehicles, both belt-pulley systems and x-drive by wire are present. The low efficiency and operational costs of belt-pulley power transmission systems necessitate the adoption of more efficient transmission systems. This study focuses on the development of a soft magnetic composite (SMC) core magnetic gear power transmission system that can serve as an alternative to belt-pulley systems in both traditional and next-generation vehicles. In the proposed system, mechanical power transfer to the Lundell alternator is realized through the intended magnetic gear. The gear ratio is determined to ensure a speed of 1800 rpm at the input of the Lundell alternator while the drive system operates at 6000 rpm. To achieve low volume and high efficiency for the proposed magnetic gear, the SMC material is considered, and a comprehensive analysis using the Ansys Maxwell finite element software is conducted. As a result of the analyses, in the magnetic gear designed with a transmission ratio of 3:1, when a torque of 11.7547 Nm is applied to the input shaft, a torque transmission of 35.9806 Nm has been achieved with an efficiency of 84.73% through the output shaft.

Keywords

• Magnetic gear
• soft magnetic composite (SMC)
• power transmission systems
• vehicle powertrain systems.

References

1. [1] K. Atallah, D. Howe. “A novel high performance magnetic gear.” K. Atallah, D. Howe. "A novel high performance magnetic gear." IEEE transactions on magnetics, vol.37. 4, 2001, pp 2844-2846.
2. [2] P. O. Rasmussen, T. O. Andersen, F. T. Jorgensen, O. Nielsen, "Development of a high-performance magnetic gear," IEEE Transactions on Industry Applications, vol. 41. 3, 2005, pp. 764-770.
3. [3] J. W. K. Atallah, D. Howe, "A high-performance linear magnetic gear," Journal of applied physics 97, vol. 10. 516, 2005.
4. [4] S. Nielsen, R. K. Holm, N. Berg, P. O. Rasmussen, "Magnetically geared conveyor drive unit - an updated version," IEEE Energy Conversion Congress and Exposition (ECCE), 2020.
5. [5] L. Jian, K. T. Chau, "Analytical calculation of magnetic field distribution in coaxial magnetic gears," Progress in Electromagnetics Research, vol. 92, 2009, pp. 1-16.
6. [6] A. B. W. Hafla, W. Rucker, "Efficient design analysis of a novel magnetic gear on a high performance computer," The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 26. 3, 2007, pp. 712-726.
7. [7] K. T. Chau, Z. Zhang, "Novel design of double-stator single-rotor magnetic-geared machines," IEEE Transactions on Magnetics, vol. 48. 11, 2012, pp. 4180-4183.
8. [8] P. Alotto, E. Armando, "Design, Analysis and Realisation of a Magnetic Gear Prototype with Experimental Validation," 23rd International Conference on the Computation of Electromagnetic Fields, 2022.

9. [9] L. Dimauroa, E. Bonisolia, M. Velardocchiaa, M. Repettob, P. Alottoc, M. Filippinic, R. Torchioc "Magnetic gearbox for automotive power transmissions: an innovative industrial technology," Engineering Science and Technology an International Journal, 2023.
10. [10] D. Wong, H. Baninajar, B. Dechant, J. Bird, "Designing a Magnetic Gear for an Electric Aircraft Drivetrain," IEEE Energy Conversion Congress & Expo, 2020.
11. [11] S. C. K. Atallah and D. Howe, "High-performance magnetic gears," Journal of Magnetism and Magnetic Materials, 2004, pp. 272-276.
12. [12] G. Duan, T. Gupta, E. Sutton, M. Wang; M. C. Gardner, "Cycloidal Magnetic Gear Combining Axial and Radial Topologies," IEEE Transactions on Energy Conversion Vol.37, 3, 2022, pp.1-1.
13. [13] M. Filippini, P. Alotto, V. Cirimele, M. Repetto, C. Ragusa, L. Dimauro, E. Bonisoli, "Magnetic Loss Analysis in Coaxial Magnetic Gears," Journals Electronics Vol. 8, 11, 2019.
14. [14] N. Frank, H. Toliyat, "Gearing ratios of a magnetic gear for marine applications," in IEEE Electric Ship Technologies Symposium, ESTS., 2009.
15. [15] N. Frank, H. Toliyat, "Gearing ratios of a magnetic gear for wind turbines," in IEEE International Electrical Machines and Drives Conference, IEMDC'09., 2009.
16. [16] M. F. A. Halim, E. Sulaiman, M. Jenal, R. N. F. K. R. Othman, S. M. N. S. Othman, "Preliminary analysis of eddy current and iron loss in magnetic gear in electric vehicle," International Journal of Electrical and Computer Engineering (IJECE) 12(2):1161, 2022.
17. [17] Y. Tian, G Liu, W. Zhao, J. Ji, "Design and Analysis of Coaxial Magnetic Gear Considering Rotor Losses," IEEE Transactions on Magnetics 51(11):1-1, 2015.
18. [18] E.J. Park, S.Y. Jung, Y.J. Kim, "Comparison of Magnetic Gear Characteristics Using Different Permanent Magnet Materials," IEEE Transactions on Applied Superconductivity Vol. 30, 4, 2020.
19. [19] E. Mese, M. Ayaz, M. Tezcan, K. Yilmaz, "Design of dual winding permanent magnet synchronous machines for hybrid electric vehicle accessory drives." International Journal of Vehicle Design, 69(1-4), 185- 207, 2015.
20. [20] Y. Öner, "Rüzgar türbinleri icin; düşük hızlı, sürekli mıknatıslı, yumuşak manyetik kompozit malzemeli, senkron generator tasarımı, optimizasyonu ve üretimi," Doktora Tez, 2013.
21. [21] O. Ocak, "Sürekli mıknatıslı senkron motorlarda moment kalitesini artırmaya yönelik melez mıknatıs yerleşimli yeni bir rotor yapısı tasarımı ve deneysel doğrulaması," Doktora Tez, 2021.
22. [22] Kocaer, T. & Öner, Y. (2022). Axial Flux Motor Design for Ventilation Fans Used in The Automotive Industry . Balkan Journal of Electrical and Computer Engineering , 10 (3) , 295-299.