Due to the simple structure of automobile bearings, the difference in appearance is often not obvious. However, looking at the history of bearing technical characteristics from the 1980s to the present, it can be found that the basic performance of bearings continues to develop under the expectation of market demand. This article introduces the latest developments in automotive bearing (deep groove ball bearings, tapered roller bearings) technology in terms of low fuel consumption (low torque). 1 Development History of Automobile Bearings 1.1 Deep Groove Ball Bearings In order to meet the market demand of high-efficiency multi-stage automatic transmissions and continuously variable transmissions, the functions of deep groove ball bearings mainly used in transmissions have been improved, including high-speed and low-torque applications. In addition to the requirements of compactness, light weight and long service life, the drive motor bearings of electric vehicles also face similar technical requirements. Low torque requirements and compact, lightweight designs are achieved through changes in materials, heat treatment, internal design parameters, and improvements such as seals, cages, and greases (Figure 1). Figure 1 Deep groove ball bearings and their characteristics The structure and performance characteristics of different types of deep groove ball bearings are shown in Table 1. By comparing torque, the technical history of deep groove ball bearings since the 1980s is shown in Figure 2. Table 1 Characteristics of deep groove ball bearings Figure 2 Development and evolution of deep groove ball bearings The deep groove ball bearings used in transmissions are usually open bearings without dust covers or seals. However, contact seals (LU/LH seals) are currently used to prevent the intrusion of hard foreign matter into the lubricating oil, resulting in reduced bearing service life. Due to the influence of the sliding properties of the seals, contact sealed bearings have higher torque than open bearings. Therefore, open bearings are often used where low torque is a critical requirement. Improvements in materials and heat treatment techniques enable bearings to have a longer service life in ambient conditions where foreign matter is intruded. The newly developed LE seal has improved sealing material and sealing lip structure to obtain low torque while ensuring sealing performance. These improvements allow LE seals to have as low torque as non-contacting seals in oil-lubricated conditions. 1.2 Tapered Roller Bearings Tapered roller bearings for transmissions or differentials have more design elements than deep groove ball bearings. Therefore, various properties of these design parameters are explored. In addition to low torque, improvements in materials and heat treatment have also resulted in a long service life (Figure 3). Figure 3 Tapered roller bearings and their characteristics This section discusses the transition to lower torques due to improvements in internal design and material/heat treatment. In order to improve the internal design, the ST series was established to reduce the torque by improving the sliding characteristics of the rollers. This is mainly achieved by the special shape and processing of the inner ring rib. In terms of material/heat treatment improvement, special heat treatment is carried out on the basis of carburized steel. Thanks to this special heat treatment technique, the retained austenite on the raceway surface is increased, which helps to prolong the service life. The calculation results of the compaction effect torque are shown in Fig. 4. Figure 4 Development of tapered roller bearings With the improvement of the inner/outer raceway micro-curvature (camber), and combining this technology with other materials/heat treatment technologies for product development, the ECO-Top series is obtained. In addition, changing the steel cage design can significantly reduce the stirring resistance of the lubricating oil. In the latest series, ULTAGE tapered roller bearings for automobiles meet the needs of lightweight and compact applications in modern hybrid/electric vehicles (HEV/EV) by improving the crown design and establishing batch processing technology. ULTAGE® is NTN's name for a bearing that combines 'ultimate' (excellence) and 'stage' (series bearing versatility). Additionally, ULTAGE® is the umbrella term for a new generation of bearings that NTN is known for for its industry-leading performance. In addition, a long-life heat treatment 'FA process' has been developed based on globally available bearing steel. Compared to the standard series, ULTAGE tapered roller bearings achieve longer service life and significantly reduced torque (fig. 4). Improvements, such as the optimization of contact stress distribution mentioned later, contribute to longer life. 2. Introduction of next-generation automotive bearings Next, we will introduce the next-generation deep groove ball bearings and the newly developed tapered roller bearings for low-fuel-consumption vehicles. 2.1 Ultra-low friction sealed ball bearings In order to prevent the bearing life from being reduced in harsh environments with hard foreign bodies in the transmission lubricating oil, contact seals are usually used to improve the ability to resist foreign bodies (such as abrasive particles from gears). However, due to the sliding resistance of the seal, the contact seal bearing has a large torque. LE seals optimize seal shape and material to achieve low torque while maintaining a contact seal. This seal successfully reduces torque and increases limit line speed. LE seals achieve these effects by promoting the formation of a fluid lubricant film between the seal lip and the inner ring sliding surface by the wedge pressure effect of the arcuate (semi-cylindrical) microconvex (Fig. 5) provided in the sliding area of ​​the seal lip (Table 2, Image 6). Figure 5 Features of ultra-low friction sealed ball bearings The features of the developed products are: 1) Compared with contact seals, the torque is reduced by more than 80%; 2) Supports high linear speeds ≥ 50 m/s; 3) Prevents harmful foreign body intrusion