NSK Develops World’s Fastest Ball Bearing for EV Motors

 

World’s first cage designed with topology optimization and leading edge simulation technology

NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President & CEO: Akitoshi Ichii) has developed a third generation ultra high speed ball bearing for electric vehicle (EV) motors capable of operating at over 1.8 million dmN*1. The new bearing is the world’s fastest grease-lubricated deep groove ball bearing for automotive applications, enabling longer vehicle range and higher energy (fuel) economy. The bearing also facilitates motor and component downsizing for gains in vehicle interior space.

NSK is targeting 12 billion yen in sales by 2030.

*1 dmN: A measure of bearing rotational performance. The product of bearing pitch diameter (dm) in millimeters and rotational speed (N).

Background

Protecting the environment is vital to the continued prosperity of societies around the world. To enhance sustainability, the automotive industry is rapidly moving to help achieve a carbon neutral society by expanding the development and production of electric vehicles, hybrids, and other new energy vehicles. However, maximum range on a single charge remains a concern for consumers.

In light of consumer and environmental demands, automakers are pursuing smaller and lighter automotive components, and developing faster, higher output motors operating at higher efficiencies. Accordingly, bearings used in powertrains, especially in electric motors, are being subjected to increasingly higher speeds and performance demands.

NSK has been engaged in development efforts on an ongoing basis and completed development of the second generation ultra high speed ball bearing (1.4 million dmN) in March 2020. The second generation design featured significant advancements in cage and anti-seizure technology. Today, NSK announced the third generation model aligned with demand for bearings capable of even higher speeds in electric motors for EV.

Product Features

1. World’s First Cage Designed with Topology Optimization
Topology optimization contributed to reducing weight to the utmost limit by removing parts that do not contribute to the strength and rigidity of the cage, and to deriving the optimal cage shape for high-speed rotation. The cage was developed with a very short turn around by utilizing leading edge simulation technology to verify performance and production considerations.
2. Proprietary NSK Grease for Superior Seizure Resistance
The bearing is filled with a special NSK grease that reduces churning resistance and heat generated therefrom, prolonging both grease and bearing life as well as reducing the risk of seizure.
3. New High Rigidity Cage Material
The cage is made with a new high rigidity resin material that is more effective at suppressing deformation during high-speed rotation than conventional materials.

The proprietary NSK grease and newly developed cage enables bearing operation at over dmN 1.8 million.

                                                                    Design steps for new cage

Customer Benefits

NSK’s newly developed bearing offers the highest permissible speeds in the world*2 for automotive motors. This enables customers to develop and implement electric motors that operate at significantly higher speeds. Higher motor output contributes to improving fuel economy (reducing power consumption per unit distance), increasing maximum vehicle range, and contributing to enhanced user comfort.

Higher speeds also enable utilization of smaller motors, reducing vehicle weight and increasing space for other components, more battery cells, or a larger vehicle interior.

*2: Based on NSK investigation of grease filled automotive bearings.