The research team led by Hong Do-gwan at the Korea Electrotechnology Research Institute (KERI) announced on the 27th that they developed the world's first "non-contact magnetic gear applied counter-rotation propeller" technology. This technology aims to improve the efficiency of electric propulsion systems for vessels, focusing on reducing energy consumption while increasing thrust compared to conventional propellers.
The counter-rotation propeller operates with two propellers rotating in opposite directions, one at the front and the other at the back. The front propeller generates rotational energy that the rear propeller converts back into thrust, achieving more than 10% efficiency compared to existing single propellers. However, the conventional method using mechanical gears has disadvantages, such as significant heat, noise, and vibrations due to friction, as well as complicated maintenance.
In response, the research team applied the non-contact magnetic gear developed in 2022 to the counter-rotation propeller. The non-contact magnetic gear transmits power without friction by utilizing the pushing and pulling force between the north and south poles of magnets, marking a world-first development by the research team.
The research team tested the non-contact magnetic gear applied counter-rotation propellers rated at 3 kW (kilowatts, 4 horsepower) and 10 kW (13.5 horsepower) on a small unmanned vessel. Recently, they declared that they achieved a level of output suitable for four adult passengers, reaching up to 50 kW. This technology can drive electric propulsion vessels up to 8 meters in size and could be used in future water taxis or electric boats for tourism.
Currently, the research team is aiming to achieve an output of over 100 kW and plans to realize a "direct current distribution electric vessel system" that can transport dozens of people by equipping three 100 kW units for marine mobility. KERI anticipates that this achievement can be applied not only to eco-friendly mobility but also to defense, automation industries, and plans to commercialize it through technology transfer to related corporations.
Hong Do-gwan remarked, "Based on diverse research experience and know-how, we minimized trial and error through various efforts, including the design of key components," adding that it will greatly change the landscape of eco-friendly maritime mobility with its high thrust efficiency, fuel cost savings, low noise, low vibration, and the advantage of a semi-permanent lifespan that requires no maintenance.