a brand new proprietary lubrication mechanism considerably reduces the mandatory lubricant provide, contributing to longer eVTOL flight vary
NSK Ltd. has launched a brand new gasoline turbine generator bearing for eVTOLs1 together with giant drones, which is anticipated to increase drone flight vary.
The brand new product was used for the gasoline turbine generator of a giant drone (excessive payload emergency provide supply drone outfitted with a gasoline turbine generator) outfitted with an 80-kw hybrid drive system for a regional reconstruction and sensible improvement promotion venture in fiscal 2023, and delivered to Fukushima Prefecture on February 21, 2024.
NSK goals to realize annual gross sales of 1.0 billion yen by 2030 for this product.
1 eVTOL: electrical vertical take-off and touchdown plane
1. Background
In recent times, improvement of eVTOLs has been shifting ahead as a brand new technique of transportation, with a predicted market measurement of 20 trillion yen by 2035. Beforehand, mainstream eVTOL propulsion methods have been fully motorized, however to fulfill the rising want for longer flight vary and improved transportation capabilities, demand for high-output, compact, light-weight hybrid motors is anticipated to proceed rising. Gasoline turbine mills stand out from different hybrid motorized fashions as a result of they will use varied gas sources corresponding to biofuels and hydrogen, making them engaging from a carbon neutrality perspective. Now, gasoline turbine mills are the strongest contender for sensible propulsion mechanisms.
To contribute to longer flight vary, decreasing weight (i.e., making oil provide scavenge pumps and the lubricant tank lighter), and delivering high-speed revolution efficiency is required of gasoline turbine generator bearings. To fulfill this want, the market problem is making certain high-speed revolution efficiency (over 2.5 million dmn) with minimal lubrication.
2. Options
NSK has developed a brand new lubrication mechanism that reduces the quantity of lubricating oil the bearing requires whereas additionally reducing energy loss. This design ensures high-speed revolution efficiency (over 2.5 million dmn) with the optimum, minimal quantity of lubricating oil.
1) Decreasing the quantity of lubricating oil
The brand new product reduces the quantity of lubricating oil to 1 quarter of the traditional jet lubrication mechanism.
⇒Light-weight oil provide scavenge pumps and lubricant tank
2) Decreasing power loss (energy loss)
The brand new product reduces the facility loss to 2 thirds of the traditional jet lubrication mechanism.
3) Guaranteeing high-speed revolution efficiency (over 2.5 million dmn)
3. Expertise
1) Overview of the brand new lubrication mechanism
The issue with jet lubrication, a typical lubrication mechanism used for high-speed bearings, is that it requires a considerable amount of lubricating oil and causes excessive energy loss. NSK’s new product resolves this problem by incorporating under-race lubrication as utilized in increased revolution purposes, delivering lowered energy loss and lubricating oil quantity.
2) Points with the traditional lubrication mechanism
Jet lubrication makes use of extremely suitable components, spacers, within the oiling mechanism, making it versatile and cost-effective, however a big quantity of oil is forcibly equipped at excessive stress from exterior the bearing, leading to giant quantity lubricating oil utilization and vital energy loss.
Then again, under-race lubrication makes use of devoted movement channels within the shaft and bearing internal race to immediately provide oil, a way which has low versatility and excessive price. The profit is that, since solely the mandatory quantity of oil (minimal) is equipped through centrifugal drive, this methodology is affords minimal energy loss and oil utilization.
3) New lubrication mechanism
NSK’ new lubrication mechanism options an improved spacer form permitting for direct provide of the mandatory quantity of oil (minimal) to the within of the bearing utilizing centrifugal drive. This answer reduces the quantity of lubricating oil and energy loss, yielding a brand new extremely versatile, low-cost lubrication mechanism.
SOURCE: NSK
