NSK Ltd. has released a new gas turbine generator bearing for eVTOLs including large drones, which is expected to extend drone flight range. The new product was used for the gas turbine generator of a large drone (high payload emergency supply delivery drone equipped with a gas turbine generator) equipped with an 80-kw hybrid drive system for a regional reconstruction and practical development promotion project in fiscal 2023 and delivered to Fukushima Prefecture on February 21, 2024. 

In recent years, development of eVTOLs has been moving forward as a new means of transportation, with a predicted market size of 20 trillion yen by 2035. Previously, mainstream eVTOL propulsion systems were completely motorized, but to meet the growing need for longer flight range and improved transportation capabilities, demand for high-output, compact, lightweight hybrid motors is expected to continue growing. Gas turbine generators stand out from other hybrid motorized models because they can use various fuel sources such as biofuels and hydrogen, making them attractive from a carbon neutrality perspective. Now, gas turbine generators are the strongest contender for practical propulsion mechanisms.

To contribute to longer flight range, reducing weight (i.e., making oil supply scavenge pumps and the lubricant tank lighter), and delivering high-speed revolution performance is required of gas turbine generator bearings. To meet this need, the market challenge is ensuring high-speed revolution performance (over 2.5 million dmn) with minimal lubrication.

NSK has developed a new lubrication mechanism that reduces the amount of lubricating oil the bearing requires while also lowering power loss. This design ensures high-speed revolution performance (over 2.5 million dmn) with the optimal, minimal amount of lubricating oil.

nsk.com