Mining Machinery Fan Blades,Aluminum Fan Blades For Excavator,Axial Fan Impeller For Mining Loader,6 Blades Die-Casting Aluminum Impeller Changzhou Keyleader Fan Technology Co. Ltd. , https://www.keyleaderfan.comThe Use of Metal Self-Correcting Materials on Bearings (1)
Self-correcting materials for metal wear are made from a group of ultra-fine natural ore powders. When added to lubricating grease or oil, these materials undergo a chemical reaction under the heat generated by friction during bearing operation. This process leads to the formation of an iron-based silicate wear-resistant layer—essentially a ceramic coating—on the surfaces of the rolling elements and raceway. As a result, the service life of the bearing is significantly extended.
Since the reform and opening-up policy, China's bearing industry has made remarkable progress. By 2000, China had become the fourth-largest bearing producer globally, after Japan, the United States, and Germany. Annual output exceeds 2 billion sets, with a value of about 24 billion yuan. More than half of the production is exported, generating approximately 700 million U.S. dollars in foreign exchange annually. In recent years, Chinese bearings have shown significant improvements in scale accuracy, rotational precision, noise levels, and reliability. However, compared to bearings from developed countries, there is still a noticeable gap in both variety and quality.
To bridge this gap, further development in product types, quality control, testing, and application is necessary. The use of self-correcting materials in domestic bearings enhances reliability, reduces friction between the rolling elements and raceway, and greatly extends the bearing’s lifespan. This advancement moves general bearings closer to the concept of "infinite life," offering substantial economic benefits.
**First, the Quality of Bearing Products in China:**
From 1997 to 1999, according to the National Supervision and Inspection Product Catalogue issued by the State Bureau of Quality and Technical Supervision, the pass rate for rolling bearings was 68% over three years. In 2000, the pass rate increased by 6 percentage points, showing the positive impact of quality supervision. Compared to leading international manufacturers, Chinese bearings still lag behind in several key areas:
1. **Limited Variety and Low Output:** China produces around 20,000 types of bearings, while the total number of types produced by the global top five companies (SKF, NSK, KOYO, NTN, NMB) far exceeds this. Domestic companies also struggle with low production volumes and limited specialized products.
2. **Large Variations in Precision:** Although China has improved its scale and rotational accuracy, there is still a significant gap in dimensional tolerance compared to foreign brands.
3. **Noise and Vibration Issues:** The oscillation level of Chinese bearings is more than 10 dB higher than that of foreign brands. For example, the noise level of a 6202 bearing from a foreign brand is around 26 dB, while domestic samples range from 37.5 dB.
4. **Shorter Lifespan and Lower Reliability:** Foreign deep groove ball bearings often last 8–30 times their calculated life, with a reliability of up to 0.98. In contrast, Chinese bearings typically last only 3–5 times the calculated life, with a reliability of around 0.96.
Due to these shortcomings, China must import many high-quality bearings each year for use in home appliances, automobiles, textile machines, and other industries. These imported bearings include low-noise ball bearings, long-life automotive bearings, high-speed spindle bearings, and railway car bearings. In 1999, China imported 640 million sets; by 2001, the number had risen to 720 million.
Because of the shorter lifespan of domestic bearings, they cannot match the performance of electromechanical equipment, leading to frequent replacements, reduced equipment utilization, and higher maintenance costs. To address this, advanced bearings in developed countries now focus on "infinite life" and "zero failure" goals. Chinese bearings must continue to improve in life span and reliability to meet global standards.
**Recommended Reading:**
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- Tips for selecting high-quality bearings for general machinery
This article is linked from http://www.chinabearing.net
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The use of metal self-correcting materials on bearings (1)
Source: China Bearing Network | Date: May 23, 2013