▲ Hong Do-gwan, a senior researcher at the Korea Electrotechnology Research Institute, explains ‘non-contact magnetic power transmission technology.’



Propulsion efficiency and energy saving effect ↑

No noise or vibration, interest from land, sea and air

Dr. Hong Do-kwan's team at the Korea Electrotechnology Research Institute (KERI) presented the world's first 'non-contact magnetic gear-based counter-rotating propeller propulsion' technology at the Korea Electric Power Industry Exhibition.

The Korea Electrotechnology Research Institute introduced the research institute's key areas of focus, including electric power equipment, electric propulsion, and industrial application technology, at the Korea Electric Power Industry Fair held at COEX in Seoul from the 17th to the 19th.

The technology of the 'non-contact magnetic gear-based counter-rotating propeller propulsion' developed by Dr. Hong Do-kwan's team at the Electric Power System Research Center, which can improve the propulsion efficiency of ships and aircraft by more than 10%, also attracted attention.

'Upper half rotation A 'propeller' is two propellers arranged axially, rotating in opposite directions.

While conventional thrusters are equipped with only one propeller, pushing 70% of the propulsive force backwards and 30% flowing sideways, wasting energy, the 'contra-rotating propeller' recovers and recycles the rotational energy from the front propeller by having the rear propeller rotate in the opposite direction, so it improves propulsive force and propulsion efficiency for the same power requirement, and reduces power requirement for the same propulsive force, resulting in an energy-saving effect.

▲ Counter-rotating propeller principle (Image source: Korea Electrotechnology Research Institute)

Previously, creating a mechanism to turn two propellers in opposite directions required the use of mechanical gears.

Dr. Hong's team developed a 'non-contact magnetic gear' that can create the propulsive force of a counter-rotating propeller by transmitting power without contact between gear parts by utilizing the mutual pushing and pulling force of the north and south poles of a magnet, and applied it to underwater and aerospace propulsion systems.

Recently, we even completed a demonstration test of an underwater propulsion device that achieved a maximum efficiency of 99% using non-contact magnetic gears in a reservoir near KERI Changwon headquarters.

Since it utilizes the power of non-contact magnets, it is expected to receive significant attention in the defense field as it produces almost no noise or vibration. Another great advantage is that it has a semi-permanent lifespan and therefore requires little maintenance.

Dr. Hong Do-kwan said, “We will not stop here, but will develop technology for unmanned autonomous navigation to enable smart autonomous navigation at sea.” He added, “We will focus on research and development so that our non-contact magnetic power transmission technology can be expanded to various mobility fields beyond underwater and aerial use.”

The non-contact magnetic gear-based counter-rotating propeller currently developed by the research team has a 3kW output level for unmanned vehicles.

Dr. Hong also announced a goal to achieve a 10kW-class unmanned vehicle by 2022, and a performance of over 100kW, enough to carry dozens of people, by next year.

Meanwhile, the Korea Electrotechnology Research Institute received much attention from visitors at the Electric Power Industry Expo by exhibiting various technologies in key areas of promotion, including △core electric propulsion technology for next-generation urban mobility aircraft and △electric vehicle charging control and communication technology.