Bearing introduction and industry development
Bearing is an important part of contemporary machinery. Its main function is to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its rotation accuracy.
According to the friction properties of moving components, bearings can be divided into two categories: rolling bearings and sliding bearings. Among them, the rolling bearing has been standardized and serialized, but its radial size, vibration and noise are larger and the price is higher than that of the sliding bearing.
Rolling bearings generally consist of an outer ring, an inner ring, a rolling element and a cage. According to the shape of the rolling element, the rolling bearing is divided into two categories: ball bearing and roller bearing.
Bearings are components that fix and reduce the coefficient of friction of the load during mechanical transmission. It can also be said that when other parts move relative to each other on the shaft, the mechanism for reducing the coefficient of friction during power transmission and maintaining the center position of the shaft is fixed. Bearings are a very important part of contemporary machinery. Its main function is to support the mechanical rotating body to reduce the mechanical load friction coefficient of the equipment during the transmission process. According to the friction properties of moving components, bearings can be divided into rolling bearings and sliding bearings.
China is one of the first countries in the world to invent rolling bearings. In ancient Chinese books, the structure of axle bearings has long been recorded. From the archaeological relics and materials, China's oldest bearing with the prototype of modern rolling bearing structure appeared in Xuejiaya Village, Yongji County, Shanxi Province, from 221 to 207 BC (Qin Dynasty). After the founding of New China, especially since the 1970s, under the strong impetus of reform and opening up, the bearing industry has entered a new period of high quality and rapid development.
At the end of the seventeenth century, the British C. Vallo designed and manufactured ball bearings, and installed on the mail truck trial and the British P. Worth patented ball bearings. At the end of the eighteenth century, H.R. Hertz of Germany published a paper on the contact stress of ball bearings. On the basis of Hertz's achievements, R. Stebbeck of Germany and A. Palmer of Sweden conducted a large number of experiments, which contributed to the development of the design theory and fatigue life calculation of rolling bearings. Subsequently, N.P. Petrov of Russia applied Newton's law of viscosity to calculate bearing friction.
The British O. Renault conducted a mathematical analysis of Thor's discovery and derived the Reynolds equation, which laid the foundation for the fluid dynamic lubrication theory. In the early form of linear motion bearings, a row of wood poles was placed under a row of rafts. This technique may be traced back to the construction of the Great Pyramid of Giza, although there is no clear evidence. Modern linear motion bearings use the same principle of operation, except that balls are sometimes used instead of rollers. The earliest sliding and rolling element bearings were made of wood. Ceramics, sapphires or glass are also used. Steel, copper, other metals, plastics (such as nylon, bakelite, Teflon and UHMWPE) are commonly used.
From heavy-duty wheel axles and machine tool spindles to precision timepiece components, rotary bearings are required for many applications. The simplest rotary bearing is a bushing bearing, which is simply a bushing sandwiched between the wheel and the axle. This design was subsequently replaced by a rolling bearing that replaced the original bushing with a number of cylindrical rollers, each rolling body being like a separate wheel. The first practical rolling bearing with cage was invented by watchmaker John Harrison in 1760 for the production of the H3 chronograph.
An example of an early ball bearing was found on an ancient Roman ship found in Lake Nami, Italy. This wooden ball bearing is used to support a rotating table top. This ship was built in 40 BC. It is said that Leonardo da Vinci described a ball bearing around 1500. Among the various immature factors of ball bearings, it is important that collisions occur between the balls, causing additional friction. But this can be prevented by putting the ball in a small cage.
In the 17th century, Galileo made the earliest description of the "fixed ball" or "cage ball" ball bearings. But for a long time afterwards, mounting the bearings on the machine has not been achieved. The first patent on the ball channel was obtained by Carmarthen's Philip Vaughan in 1794.
In 1883, Friedrich Fisher proposed the use of a suitable production machine to grind steel balls of the same size and roundness. This laid the foundation for the creation of an independent bearing industry. The initials of "Fischers Automatische Guß stahlkugelfabrik" or "Fischer Aktien-Gesellschaft" became trademarks and were registered on July 29, 1905.
In 1962, the FAG trademark was revised and used today, and in 1979 became an integral part of the company.
In 1895, Henry Timken designed the first tapered roller bearing, and after three years patented and established Timken.
In 1907, Sven Winquist of SKF Bearing Factory designed the earliest modern self-aligning ball bearings.
Industry development
Bearings are important basic components of all kinds of mechanical equipment. Its accuracy, performance, longevity and reliability play a decisive role in the accuracy, performance, life and reliability of the main engine. In mechanical products, bearings are high-precision products, which not only require comprehensive support of many disciplines such as mathematics and physics, but also require materials science, heat treatment technology, precision machining and measurement technology, numerical control technology and effective numerical methods and powerful computers. Technology and many other disciplines serve it, so the bearing is a product that represents the strength of the country's science and technology.
After the outbreak of the international financial crisis in 2008, the state adopted a proactive fiscal policy of increasing infrastructure investment and stimulating economic development in response to the financial crisis. Benefiting from the development of related industries, the production and sales of bearings have expanded rapidly, the profit level has been improved, and the industry has accelerated significantly. According to the “China Bearing Manufacturing Industry Production and Demand Forecast and Transformation and Upgrade Analysis Report” released by the Prospective Industry Research Institute, in 2011, China’s bearing manufacturing industry scale (annual sales income of more than 20 million yuan) has 1,416 enterprises, achieving industrialization throughout the year. The total output value was 193.21 billion yuan, a year-on-year increase of 27.59%; the sales income was 191.907 billion yuan, a year-on-year increase of 30.30%; the total profit was 12.523 billion yuan, an increase of 26.54% over the previous year.
In recent years, world-renowned companies have entered the Chinese bearing market and established production bases, such as the Swedish SKF Group, the German Schaeffler Group, the American Timken Company, the Japanese NSK Company, and the NTN Company. These companies are not only globally operated, but also globally manufactured. They rely on the advantages of brand, equipment, technology, capital and production scale to compete fiercely with domestic bearing companies. Today, domestic companies are mainly engaged in the production of general-purpose bearings. There are fewer special-purpose and high-end bearing manufacturers, and the technology is still immature. Therefore, if domestic enterprises want to compete with foreign advanced bearing brands or even surpass them, they still need to go through a long period of development in technology and other aspects.
During the "Twelfth Five-Year Plan" period, the effects of the state's macroeconomic policies will continue to show, domestic economic growth will remain strong, the international market will also slowly recover, and the momentum of economic stabilization will gradually increase. The development of the national economy will boost investment in infrastructure construction, and promote the development of metallurgy, electric power, construction machinery, building materials, energy and other industries. At the same time, the country has introduced ten major industrial revitalization plans for the automotive, aerospace, machine tools, wind power and other industries. Development provides policy support, and the demand for bearings in these industries will gradually expand. In addition, the country's emphasis on equipment manufacturing and the trend of bearing localization are increasingly obvious, China's bearing market will usher in a broader space for development. At the same time, with the development of China's bearing mainframe industry, the product structure of the bushing will change, the proportion of its high-end products in the product will increase, and the unit price of sales will also increase. It is expected that by 2015, China's bearing output is expected to exceed 28 billion. The main business income is expected to reach 210 billion yuan, becoming the world's largest bearing production and sales base.
With the increasing competition in the bearing manufacturing industry, M&A integration and capital operation among large bearing manufacturing companies are becoming more and more frequent. Domestic excellent bearing manufacturers are paying more and more attention to the research of the industrial market, especially for the industrial development environment and product buyers. In-depth study. Because of this, a large number of domestic excellent bearing manufacturing brands have risen rapidly and gradually become the leader in the bearing manufacturing industry!
