18 January 2024

Sumitomo Electric Industries, Ltd. (Headquarters: Chuo-ku, Osaka; President: Osamu Inoue; hereinafter referred to as “Sumitomo Electric”) has announced that its powder magnetic cores for axial flux motors are being used in the industry-first flat DC motor for the home air purifier “Humidifying Streamer Air Purifier MCK904A,” which was released by Daikin Industries, Ltd. (Headquarters: Kita-ku, Osaka; President and CEO: Masanori Togawa; hereinafter referred to as “Daikin”) on November 8, 2023.



By incorporating Sumitomo Electric's patented double-flanged powder magnetic cores into their flat DC motor, Daikin has increased the opposing surface area between the stator and rotor while maintaining the winding space, thereby achieving a thinner design without sacrificing performance.




Comparison between the new and conventional motor models (data provided by Daikin)

■ Reference: Press release from Daikin:
Launch of home air purifier “Humidifying Streamer Air Purifier (MCK904A)”
(Press release in Japanese only; https://www.daikin.co.jp/press/2023/20230920_1)

■ Features of axial flux motors
Amidst growing demand for lighter and higher-performance motors, axial flux motors are increasingly attracting attention thanks to their lighter weight, thinner shape, and higher power density, all properties which have been achieved by innovating the basic structure of conventional (radial flux) motors. Axial flux motors excel in output density and efficiency when compared to conventional radial flux motors, especially when thinness of the motor is a priority. In short, this allows for design of thinner and lighter motors, while maintaining the same level of performance in terms of torque and maximum efficiency.

■ Features of Sumitomo Electric powder magnetic cores for axial flux motors
Powder magnetic cores (FMCM series) are components made by molding and heat-treating iron powder coated with a nano-order insulating film which exhibit excellent soft magnetic properties in the low to high frequency range. With outstanding three-dimensional design flexibility, these cores are well-suited for use as stator cores of axial flux motors.

■ Features of double-flanged powder magnetic cores
To further enhance axial flux motor performance, Sumitomo Electric pursued a core design that would allow for greater opposing surface area between the stator and rotor, while still maintaining the winding space. To this end, the company developed a new process to press-form a powder magnetic core with a flange on each end (double-flanged powder magnetic core) as a single integrated unit. The main advantages of this process are as follows:
1. A smooth flange shape can be achieved with a single molding stroke, resulting in high productivity.

* There is no need to prepare multiple molds with different shapes, as would be required with a progressive pressing process.

2. Flanges can be extended in all directions, namely, on the slot sides, inner side, and/or outer side, enabling further enhancement of axial flux motor performance.

3. It is possible to form a pseudo-arc shape in the winding section.



Now, for the first time in the industry, these advantages of Sumitomo Electric’s double-flanged powder magnetic core have been adopted for use in a mass-produced product.

Sumitomo Electric is committed to utilizing its extensive mass production experience to continue to develop its material and process technologies for powder magnetic cores. With this ongoing development, the company will remain a trusted supplier of crucial high-performance magnetic core components for various electric devices, including axial flux motors, thereby further increasing the added value of our customers’ products.

■ About registered trademarks
・“Streamer” is a registered trademark of Daikin Industries, Ltd.

(Reference)
■ Features of axial flux motors
https://sumitomoelectric.com/products/softmagneticcomposite/axialfluxmotor

■ Axial flux MotorsーThe Conceptual Evolution of Motor Structures / Sumitomo Electric Industries, Ltd.
https://www.youtube.com/watch?v=lG_qZSX0J_c