NSK Develops Low Friction Hub Unit Bearings for EV
The new bearings maintain the high reliability of conventional products despite offering lower friction. The lower friction of the new HUBs improves fuel economy (reduces energy consumption), contributing to longer travel range in EV and other vehicles. NSK is targeting 30 billion yen in sales by 2026.
Protecting the environment and reducing CO2 emissions is vital to the continued prosperity of global society. To enhance sustainability, the automotive industry is accelerating the development and production of electric vehicles, hybrids, and other new energy vehicles. However, the limited range of these vehicles remains a significant barrier to adoption.
Reducing friction is an effective method of increasing maximum vehicle range on a single charge, especially in HUBs, which support the vehicle body and are a component vital to the smooth rotation of the wheels. Accordingly, NSK directed development efforts to focus on reducing friction in HUBs with the aim of contributing to increased vehicle range.
NSK implemented improvements to the base oil and thickener components of the lubricating grease used in HUBs, achieving a 30% reduction in friction without undermining the reliability compared to conventional products.
Improvements include reducing the base oil viscosity to reduce friction caused by resistance arising from balls rolling inside the bearing. A different type of thickener was adopted, further reducing resistance. This also made the grease harder, which facilitates the grease shifting to a more optimal position within the bearing, thereby reducing stirring resistance when the balls are rolling.
HUBs packed with the developed grease contribute to improving fuel economy, vehicle range, and reducing CO2 emissions. The HUBs can be employed in any kind of vehicle, and are ideal for EV, hybrids, and new energy vehicles.
Adopting the new HUBs can increase EV range by 0.6%, which is equivalent to reducing battery weight by 1.4 kg.
These HUBs are expected to contribute to reducing around 345 thousand tons of CO2 emissions by 2026.