～Reducing fuel consumption and electricity consumption of ICE, HEV, PHEV, EV, etc.～
• Reduce rolling friction by optimizing the number of rollers
• Achieve an average friction torque reduction of 20% across all speeds, lowering and power consumption in vehicles
• "Number of rollers optimization" is also applicable to improving existing low-friction tapered roller bearings, with a sales target of 5 billion yen by 2030
NSK Corporation (hereinafter referred to as NSK) has successfully developed the 7th generation of its "Low Friction Tapered Bearings." This product reduces the average friction torque across all speeds by 20%, thereby lowering fuel and power consumption and extending the range. NSK aims to achieve of 15 billion yen for this product by 2030.
Development background
Most of the tapered roller bearings are used in the low-speed and heavy-load environment on the wheel side. Therefore, reducing the friction torque of tapered bearings can effectively improve the efficiency of the transmission system.
The application sites of tapered roller bearings in transmissions and eAxles
NSK has been striving to achieve low friction in tapered roller bearings since around 1980 through various means. In recent years, electrification of automobiles, aimed at realizing a low-carbon society, has been accelerating, increasing the demand for low friction. Additionally, Japan adopted the international fuel measurement method, the WLTC mode*1, in 2017, which has further reduced fuel consumption. Therefore, there is a growing need for friction performance in tapered roller bearings across all speed ranges.
*1 WLTC mode: An international fuel consumption measurement method introduced in Japan by the Ministry of Land, Infrastructure, Transport and Tourism in 217. The previous fuel consumption representation (JC08 mode) was measured as an overall average of low to high vehicle speeds, while the WLTC mode fuel consumption at different speeds for urban areas, suburbs, and highways.
Product features
1) Optimization of the number of rollers to reduce rolling friction, achieving an average reduction of 20% in friction torque across all speeds (ared to existing products)
The friction torque of existing products and developed products
2) This bearing can be produced using existing equipment, allowing for quick customer proposals and early market entry.
3) The "roller number optimization" this time can also be applied to improve existing low-friction tapered roller bearings.
Product technology
1)Focusing on the life advantage of tapered roller bearings, the number of rollers is optimized.
The tapered roller bearings have high durability in harsh environments and show significant life advantages. The results of validation tests also indicate that the actual life of tapered bearings is longer than the calculated life.
2) Solve problems related to the optimization of the number of rollers.
NSK utilized its long-accumulated special camber technology and cage technology for thin lubrication environments to solve the problems of excessive pressure on the heads and welding due to the optimization of the number of rollers.
