Molybdenum disulfide grease is a commonly used high-temperature lubricant. Its use temperature and application range depend on the type of its base oil.
For lithium molybdenum disulfide-based grease produced from mineral oil, its operating temperature range is between -20°C and 120°C, which is the most common type. Higher-level molybdenum disulfide grease use a composite soap, called molybdenum disulfide facility lithium oil, and its operating temperature level range is -20 ° C to 160 ° C. This composite type of molybdenum disulfide lubricant is used in practical applications. The most extensive.
In addition, there are fully synthetic high-temperature greases made of molybdenum disulfide produced from synthetic base oils, with operating temperatures ranging from -40°C to 220°C. Although this grease is not used much, its performance is impressive.
Molybdenum disulfide grease is suitable for a variety of applications, including automotive, construction and mining, agricultural equipment, bearings and ball joints, and universal joints. It resists wear, oxidation and the ability to withstand shock loads, providing excellent lubrication for a variety of industrial and vehicle applications.
However, please note that molybdenum disulfide extreme pressure grease is not suitable for lubrication of constant velocity joints on front-wheel drive vehicles. During use, we need to select the appropriate molybdenum disulfide grease according to specific working conditions and needs to ensure the best lubrication effect.
As we all know, China's high-speed rail has rushed out of the country and into the world, becoming an area many Chinese people are proud of. No country in the world can build such a safe, efficient and wide-covering high-speed rail network.
Surprisingly, although China is the world's leading infrastructure power, we must import even one bearing. According to data, in 2022 alone, China imported 1.579 billion sets of bearings, spending US$2.693 billion in foreign exchange. ; there you may wonder, thousands of bearing companies in China; why do high-speed railways still need to rely on imported bearings? What is the reason that makes us helpless and unable to be self-sufficient in one bearing?
Bearings are vital components in the field of mechanical engineering. In various machines and equipment, bearings play a key role in supporting and reducing friction. You can think of it as a "joint" of a mechanical device. Just like the joints of the human body allow our bodies to move flexibly, bearings can make the machine run more smoothly, reduce energy loss, and extend the machine's service life.
The application range of bearings is very wide, covering almost all fields of machinery and equipment in daily life. They are commonly found in various industries, such as industrial manufacturing, transportation, power energy, and aerospace. Whether it is large-scale industrial equipment or small household appliances, they are inseparable from the support of bearings. However, the bearing is not a simple component but a high-precision product. From a theoretical level, bearings involve knowledge from multiple disciplines, such as mathematics, physics, material science, heat treatment technology, precision machining and measurement technology, CNC technology, etc. Moreover, powerful computer technology is required to support it.
So, how many bearings a country can produce yearly can intuitively reflect the country's industrial strength and technological competitiveness.
Western countries have developed in the bearing industry for a long time, with more than 100 years of accumulated technical experience. The world's major bearing powers include the United States, Europe, Japan and South Korea. China is a big country in bearings; why is it not a strong country in bearings?
2019, China's bearing output was 19.6 billion sets, ranking third economically. Like the machine tool industry, we have always had huge production capacity and scale, but only a few cutting-edge fields have broken through foreign blockades, and many high-end products still rely on imports.
Unlike other mechanical parts, high-end bearings have particularly stringent requirements for materials, processing technology, and experience because these indicators determine the future reliability and life of the bearing. For example, deep groove ball bearings are bearings with steel balls between two steel rings. The reliability of foreign products is more than 98%, and the actual life is 8 to 30 times the calculated life, while the reliability of Chinese bearings is only 96%. , the actual life is 3 to 5 times the calculated life, which means that "usable" and "easy to use" are completely different concepts. This is why large aircraft such as C919, Y-20, and high-speed rail use imported bearings.
Since 2004, China has begun to focus on developing high-speed railways and locomotive equipment, introducing advanced technology and jointly designing and producing. The Ministry of Railways of China introduced high-speed trains from Siemens at 350km/h and obtained the full vehicle manufacturing technology. China High-speed Railway We have begun to have independent intellectual property rights and can export without restrictions. However, this does not mean all parts of the high-speed rail body have been localized. Our core competitiveness is mainly in vehicle manufacturing, traction power supply systems, and operation. Control systems, etc. In the era of market globalization, you cannot require a company or a country to master all types of technologies in high-end fields.
Although the high-speed rail bearing is only a small part, it affects the whole body. Bearings are mainly divided into two categories: rolling bearings and sliding bearings. Rolling bearings used in high-speed rail are generally divided into five grades: P0, P2, P4, P5 and P6. The bearing accuracy increases with the grade. For example, the spindles of high-end CNC machine tools use P5 and P6 grades, while high-tech fields such as aviation and high-speed rail use P4 grades. In the past ten years, the high-end bearings used in China's high-speed railways have been mainly imported from companies such as SKF, NTN, and German FAG.
In the high-end bearings of these companies, we can find two basic issues: "high-performance materials" and "high-quality processing." The material used to make high-speed rail bearings is bearing steel, known as the "King of Steels." It is one of the most stringent steel types in high-speed rail smelting. How to build birthing steel with "high purity" and "high uniformity" and manage the oxygen material in the steel to a minimum has constantly been a problem faced by Chinese steel companies.
However, after decades of research, we have overcome many difficulties in the production process and become a major bearing steel producer. The key lies in adding rare earths to the steel smelting step, which makes large-size inclusions that affect the fatigue life of steel. Materials are reduced by 50%, so the bearing steel produced is also called high-end rare earth-bearing steel. Although we can currently make bearing steel, it is generally electro slag bearing steel, and its high quality and purity need to be improved. Our following goal is ultra-high-purity bearing steel made by vacuum cleaner degassing smelting modern technology taken on abroad.
After the high-performance materials are solved, the rest is high-quality processing. High-speed rail bearing manufacturing involves many disciplines. Europe and the United States can produce high-quality bearings due to their mastery of ultra-long-life steel technology, fine-grained heat treatment technology, and advanced sealing and lubrication technology. This has also led to high-speed rail bearings at home and abroad in terms of precision and bearings. There are still certain gaps in vibration, life and reliability.
For example, rollers, the core component of bearings, cannot mass produce grade 0 cylindrical rollers used in high-end bearings due to insufficient systematic integration and digitalization capabilities in China. But this does not mean that China has no way to produce Chinese-made high-speed rail bearings.
With the rise of China's manufacturing industry, China's bearing manufacturing industry has also developed rapidly. There are thousands of bearing companies in China, many of which have strong production scale and technical strengths. While providing bearing products for the domestic market, these companies also export to the global market, winning a certain reputation for the Chinese bearing industry.
To enhance the competitiveness of Chinese-made bearings, Chinese bearing companies are actively conducting technology research, development, and innovation. They have increased their investment in material science, manufacturing processes, and design theory and strive to enhance the quality and performance of their products. By strengthening teamwork with universities and scientific research study organizations and presenting sophisticated foreign modern technologies, Chinese bearing companies are slowly tightening the void with the global innovative degree.
Recently, China's large-scale high-speed railway bearing test bench was officially delivered and accepted in Luoyang. The completion of this test bed marks that China will be able to conduct bearing tests on high-speed rails with speeds of 350-500 kilometers per hour in the future. This will greatly accelerate the localization process of China's high-speed rail bearings and is also an important foundation for achieving the development goals of China's industry in 2025.
However, compared with flagship products in developed countries, Chinese bearings still have gaps, especially in bearing vibration, noise and service life. To this day, the vibration limit value of Chinese-made bearings is still about 10 decibels different from that of Japanese products, and the difference in service life is nearly three times. These data may make us uneasy, but we must face these challenges bravely while recognizing our shortcomings.
China's bearing manufacturing industry has undergone a long development process and made certain achievements. Although we still rely on imported bearings in some areas, we are confident that we will gradually narrow the gap with the international advanced level through technological research and development and the improvement of competitiveness. With the country's continued support for technological innovation and industrial upgrading, China's bearing manufacturing industry will usher in a brighter future.
TRUNNANO is a globally recognized manufacturer and supplier of compounds with more than 12 years of expertise in the highest quality nanomaterials and other chemicals. The company develops a variety of powder materials and chemicals. Provide OEM service. If you need Molybdenum Disulfide, please feel free to contact us. You can click on the product to contact us.
