Derivation of torque equation for magnetic-geared motors considering magnetic interaction and application to small-scale electric vehicles

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01302
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Tohoku University
• Principal Investigator: Nakamura Kenji 東北大学, 工学研究科, 教授 (70323061)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 磁気ギヤードモータ / 磁気的相互作用 / 電気自動車 / インホイールドライブ方式

Outline of Final Research Achievements

The magnetic-geared motors, which integrate a permanent magnet (PM) motor with a magnetic gear, are suitable for small and flat structures and can achieve high torque at low speeds. Thus, it is expected to be applied to in-wheel drive electric vehicles. In this study, a torque equation that takes into account the magnetic interaction between the PM motor and the magnetic gear is derived to clarify the drive method that can improve torque and efficiency. Moreover, analytical design and prototype tests of a large-scale 500 N-m class magnetic-geared motor for application to small-scale electric vehicles are conducted. Torque density of 83 N-m/L was achieved by the prototype magnetic-geared motor.

Free Research Field

電気機器工学

Academic Significance and Societal Importance of the Research Achievements

磁気的相互作用を考慮した磁気ギヤードモータのトルク式導出し、トルクや効率を向上可能な駆動方法を明らかにしたことは、今後の磁気ギヤードモータの分野のさらなる発展につながるため、学術的意義は高いと判断できる。また、小型電気自動車への応用を想定した500N・m級の大型の磁気ギヤードモータの実証実験が成功したことは、今後の産業応用につながる成果であるため、社会的意義も極めて高いと考える。