Design and Analysis of Magnetic Gear for Advanced Air Mobilities

In recent years, electrification has rapidly advanced in various fields toward realizing a decarbonized society, and the performance improvement of electric motors is strongly required. Especially in advanced air mobility (AAM), electric motors are required to have high power density and high reliability. Magnetic gears can transmit speed and torque without mechanical contact. Therefore, there is less vibration, noise, wear, and frictional heat generation. These features provide high reliability and are desirable for AMM. This paper describes the design and analysis of a flux-modulated-type magnetic gear that has back yokes and pole pieces made of amorphous alloy to suppress iron loss even at 30,000 rpm. Moreover, the paper demonstrates the multi-polarization for increasing the power density. The designed magnetic gear has a torque density of 39.5 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{N}\cdot \mathrm{m}/\text{kg}$</tex>, 162.8 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{N}\cdot \mathrm{m}/\mathrm{L}$</tex>, and a power density of 23.3 kW/kg at 30,000 rpm.