Nippon Kayaku Co., LTD. (KAYAKU) and the Japan Aerospace Exploration Agency (JAXA) successfully developed a motor coil that can maintain its maximum power more than two times longer than a conventional model by using thermal conductive heat-resistant insulating material. Technology to extend the time duration of motor’s maximum power is imperative for the practical use of an electric aircraft.

JAXA has been engaging in research and development of an electric aircraft as one of the most promising aviation technologies for future aircraft. For an electric aircraft to efficiently take off, it is important to maintain maximum power for a brief period. However, a conventional motor cannot sustain maximum power for a long time or the coil will burn out due to the temperature increase. Thus the necessary output power was secured by using a bigger motor system, limit the operation time and maximum power of the motor, or by introducing a cooling system. Therefore, in order to realize a smaller high-performance electric aviation motor, JAXA has been seeking a coating for the motor coil that has both insulation properties and strength while promoting thermal conductivity.

On the other hand, KAYAKU, by using reactive Polyamide resin as a base, has been developing a thermal conductive heat-resistant insulating material that can be used at up to 250 degrees Celsius with high thermal conductivity and strong adhesive properties.

In a joint research collaboration that was launched in fiscal year 2011, KAYAKU applied the thermal conductive heat-resistant insulating material to the electric aviation motor coil, while JAXA tested and evaluated the motor. Consequently, a motor coil capable of doubling the time duration of maximum power with approximately 1% improvement in maximum efficiency compared with a conventional model was successfully developed.

This technology helped develop a larger power motor system, and it can also enable us to have a lighter system if we maintain the same power as that of the conventional one, thus it is expected to be applied not only to aircraft but also to large-size automobiles and various electric industrial devices that require a higher power.

—
Electric aviation motor coil using thermal conductive heat-resistant insulating material
http://www.jaxa.jp/press/2013/05/20130514_motor_coil_e.html#ref