High-speed machining can not only improve production efficiency and reduce production costs, but also help improve the surface quality of parts. In addition, with the development of material science, many new materials have been widely used, represented by aluminum and its alloys, many light metals and non-ferrous metals have been widely used in aviation, aerospace, automotive and other engineering fields to reduce the weight of parts , The processing of these materials requires high-speed cutting. Then the increase of cutting speed means the increase of the spindle speed of the machine tool. At the same time, the key matching parts of the spindle components are required to have the corresponding high-speed performance, which promotes the development of the spindle bearing technology. The structural type of the spindle bearing The common types of machine tool spindle bearings are deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings, two-way thrust angular contact ball bearings, tapered roller bearings and thrust ball bearings. Among them, angular contact ball bearings have high manufacturing precision, high limit speed, strong carrying capacity, and can bear radial and axial loads in one direction at the same time. Therefore, they are widely used in the support of high-speed machine tool spindles. High-speed angular contact ball bearings usually use 15° and 25° contact angles. Figure 1 shows the common structural types of spindle bearings for high-speed machine tools. Figure 1 　The structure type of high-speed machine tool spindle bearing. In Figure 1, the B7000-2 RZ type is a newly developed sealed angular contact ball bearing dedicated to grease lubrication by Luoyang Bearing Research Institute. The bearings of the same specification are interchangeable. This structure bearing has the characteristics of good high speed performance, good rigidity, low temperature rise and long life. The remaining three types of bearings can be used for oil lubrication and grease lubrication, and H7000 type bearings are more suitable for oil and gas lubrication.