4 Industrial Robot Bearings 4.1 Bearing Type The reducer is the core component of industrial robots, and the bearing is the key part of the reducer. The reducers for industrial robots include RV reducers, harmonic reducers, cycloid reducers, planetary reducers, etc., with the largest amount and the highest level of technology being RV reducers and harmonic reducers. The technology of the reducer bearing has also mastered the highest technology of the industrial robot reducer. As shown in Figure 11, the RV reducer bearings include thin-walled angular contact ball bearings as the main bearing of the reducer, thin-walled tapered roller bearings for eccentric shaft positioning and main body support, and cylindrical rollers for cycloid support (Needle roller) cage assemblies and thin-walled deep groove ball bearings for gear support. 1- spur gear; 2-shaft; 3-housing; 4-pin teeth; 5-RV gear; 6-main bearing; 7-support flange; 8-input gear; 9-crankshaft. Fig. 11 RV reducer bearings Fig. 11 RV reducer bearings As shown in Fig. 12, harmonic reducer bearings include thin-walled crossed cylindrical roller bearings for rigid wheels and flexible bearings for flexible wheels. Fig.12 Harmonic reducer bearings4.2 Key technologies The installation space of industrial robot bearings is limited, and lightweight thin-walled bearings and special-shaped bearings must be used. In addition, the high load, high rotation accuracy, high running stability, high positioning speed, high repeat positioning accuracy, long life and high reliability performance of industrial robots require that the supporting bearings must also have high bearing capacity, high precision, high rigidity, Low friction torque, long life, high reliability performance. The contradiction between lightweight and high performance must be considered comprehensively: 1) In product design, not only the rated dynamic load is used as the objective function, but the rated dynamic load, stiffness and friction torque and other indicators are used as the objective function. The multi-objective optimization design is carried out, and the finite element analysis method of thin-walled bearing based on ring deformation is adopted. 2) In terms of manufacturing process and equipment, develop and apply thin-walled bearings that are easy to deform, difficult to install and clamp, and difficult to process, as well as special processing technologies for ring forging, turning, heat treatment, grinding, super-finishing and assembly of special-shaped bearings and process equipment; develop high-precision detection technology for dynamic quality of robot bearings, precision grinding process of bearing rings based on grinding metamorphic layer control, and heat treatment process for micro-deformation of thin-walled bearing rings; research and development of thin-walled bearing negative clearance and protrusion Precise control technology, precision assembly technology and ferrule non-contact measurement technology. 4.3 Market Analysis From the perspective of the global market, Europe and Japan are the main suppliers of industrial robots, and ABB, KUKA, FANUC, and YASHAWA occupy the main market share of industrial robots, accounting for about 50% of the global market share. More than 70% of the market share of robot reducers is monopolized by Japan's Nabtesco (Nabtesco, which produces RV reducers) and Harmonic Drive (Harmonic drive, which produces harmonic reducers). It can be seen from Table 6 that my country's industrial robot market and domestic industrial robot sales are in a stage of rapid development: in 2014, the national industrial robot sales were 5.7 × 104 units, and the domestic industrial robot sales were 1.7 × 104 units, accounting for 29.8%; in 2016, the national industrial robot sales 8.9×104 units, domestic industrial robots sold 2.9×104 units, accounting for 32.6%; in 2020, national industrial robots sold 23.7×104 units, domestic industrial robots sold 8.3×104 units, accounting for 35%. Table 6 Sales of industrial robots in China Tab.6 Sales of industrial robots in China Take a 6-axis industrial robot as an example to analyze, it needs to be equipped with 4 RV reducers and 2 harmonic reducers, and the number of supporting bearings is 66 sets ( Table 7), worth about 6,000 yuan. In 2020, the national demand for industrial robots is about 23.7×104 sets, and 1 564×104 sets of supporting bearings are required, worth 1.4 billion yuan, of which 8.3×104 sets of domestic industrial robots are required, and 548×104 sets of supporting bearings are required, worth 500 million yuan; 2025 The national demand for industrial robots is 47 × 104 sets, and 3 100 × 104 sets of supporting bearings are required, worth 2.8 billion yuan, of which 20 × 104 domestic industrial robots are required, and 1320 × 104 sets of supporting bearings are required, worth 1.2 billion yuan. Table 7 Type and quantity of bearings for industrial robot reducer