NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President & CEO: Toshihiro Uchiyama) has developed a new tapered roller bearing for use in electric vehicles (including hybrid, fuel cell, and battery electric vehicles) that offers long-life even under severely lean lubrication conditions.
The newly developed bearings dramatically boost seizure resistance under lean lubrication, improving gearbox reliability (transmission reliability, etc.), enabling the use of smaller lubrication systems, increasing efficiency, and facilitating smaller, more compact gearbox designs.
NSK is targeting 2 billion yen in sales by 2025.
NSK is exhibiting the new tapered roller bearing alongside a host of new mobility and EV technologies at Tokyo Motor Show 2019 (Oct 24 – Nov 4).
Development Background
As public awareness of and concern for the environment continues to increase, consumers and businesses around the world are demanding better fuel economy from motor vehicles, leading to the rapid development of EVs (including hybrid, fuel cell, and battery electric vehicles).
Improving the efficiency of the gearbox and reducing the size/weight of components is essential to extending the maximum driving range of EVs. To improve efficiency and reduce size, bearings need to be small and offer low energy loss. To this end, tapered roller bearings can bear relatively large loads for their size, but have rollers held in place by a rib, which contacts the roller’s end.
As lubrication amount is reduced, conventional tapered roller bearings more frequently seize due to damage from sliding contact in this region, making it difficult to significantly simplify lubrication systems and reduce the amount of oil used. Accordingly NSK developed a new tapered bearing to overcome this hurdle and open the path to further progress.
Features
To overcome lean lubrication conditions, NSK developed a special cage that retains and distributes oil in fine grooves via capillary action. The oil is held in the cage near the roller end, and when lubrication is low, the oil seeps out of the fine grooves to the area most in need of lubrication.
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SOURCE: NSK
