As the name implies, the bearing is the general term for the components that support various shaft structures (such as rotating shafts, spindles, and transmission shafts). In principle, a bearing connects two components that have relative rotation or allows relative rotation to achieve a supporting effect efficiently and smoothly. Bearings are as indispensable as the joints that realize the movement of the limbs. People vividly compare it to the "joints" of the mechanical system.

It is worth pointing out that the embryonic form of the bearing has been formed very early. In ancient societies without large power equipment, in order to move large stones, people usually placed a number of logs on the bottom of the stones to push the stones and use the rolling of the logs to move the stones forward. The basic principles contained in this simple thought are consistent with the original intention of modern rolling bearing design. Da Vinci, the great painter and scientist of the Renaissance, showed the bearing he conceived in his manuscripts. It can be seen that this design is very close to the structure of modern rolling bearings.

Generally speaking, rolling bearings are composed of rolling elements, cages, inner raceways and outer raceways. In addition, in order to prevent the leakage and contamination of lubricating oil, seals are also parts that many rolling bearings will be equipped with. Rolling bearings can be classified into different categories according to the structural shapes, materials, and assembly forms of rolling elements, cages, inner raceways, and outer raceways. For example, according to the structural shape of the rolling elements, rolling bearings can be divided into: deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings, spherical roller bearings, tapered roller bearings and thrust tapered roller bearings. In addition, in order to be able to withstand larger loads, some rolling bearings will be made into two or more rows, such as double row angular contact ball bearings and four row tapered roller NACHI bearings.Aero engine is a master of modern industrial technology, and bearings play an important role in aero engines. Considering the requirements of transmission efficiency, structural reliability, vibration, lubrication, etc., the bearings used in aero engines are mainly rolling bearings