Although the size deviation and rotation accuracy of domestic bearings are very close to those of imported bearings. However, there is still a certain gap in dispersion with bearings imported from Germany. Foreign countries have already begun to study and apply such a fine index of rotary accuracy as "non-repeatable runout", but the research in this field in China is still blank.
2. Vibration, noise and abnormal sound.
Silent and ultra-quiet bearings have been introduced in Japan, but the ultimate vibration level of bearings in China is generally more than 10dB different from that of Japanese bearings.
3. In terms of longevity and reliability.
Taking deep groove ball bearings as an example, the life of foreign famous brand products is generally more than 8 times (up to 30 times) of the calculated life, and the reliability is over 98% (or pursuing the same life as the main engine), while the life of China bearings is generally only 3 to 5 times of the calculated life, and the reliability is about 96%.
Extended data:
At present, China's bearing industry mainly faces three outstanding problems: low production concentration, low R&D and innovation ability, and low manufacturing technology level.
First, the concentration of industrial production is low. In the global bearing sales of about $30 billion, the world's eight multinational companies account for 75% ~ 80%. Germany's two major companies account for 90% of its national total, Japan's five major companies account for 90% of its national total, and the United States 1 company accounts for 56% of its national total. However, the sales of the largest 10 bearing enterprises in China only account for 24.7% of the whole industry, and the production concentration of the top 30 enterprises is only 37.4%.
Second, the ability of R&D and innovation is low. The basic theoretical research of the whole industry is weak, and the ability to participate in the formulation of international standards is weak, with few original technologies and few patented products.
At present, the design and manufacturing technology is basically in the imitation state, and the product development ability is low, which shows that although the matching rate of domestic main engines reaches 80%, the matching and maintenance bearings of important main engines such as high-speed railway passenger cars, middle and high-grade cars, computers, air conditioners and advanced rolling mills are basically imported.
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