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Hydraulic cylinder is one of the more mature hydraulic products in China. The industry has maintained rapid growth for many years, has formed a relatively mature supply and demand chain, with a larger market size. According to the data from the liquid and air tight industry association, the sales revenue of China's hydraulic cylinder industry increased from 3.1 billion yuan in 2005 to nearly 11 billion yuan in 2010, with a five-year compound growth rate of 28.83%. However, and the same hydraulic industry, the proportion of oil cylinder in the national industrial output value is still low, far lower than the level of foreign developed countries. At the same time, China has strong market demand, low cost and other advantages, is expected to become the world's hydraulic industry and cylinder industry focus.

Along with the hydraulic technology thorough popularization and the application domain, the occasion expands day by day, to the hydraulic cylinder work performance, the structure, the use scope, the manufacture precision, the appearance, the material, the test method all puts forward the new request unceasingly, therefore unceasingly impels the hydraulic cylinder the development and the progress. Its general trend is: 1, high pressure, miniaturization. High pressure is an effective way to reduce the radial size of hydraulic cylinder, reduce weight and reduce the volume of the whole hydraulic device. 2. New material, lightweight. Along with the high pressure, miniaturization, the hydraulic cylinder service environment test and so on, the new material, the lightweight also became one of the solutions. 3. Compound novel structure. In order to adapt to the expansion of the scope of application of hydraulic cylinders, a variety of new structure of hydraulic cylinders, such as automatic hydraulic cylinder, self-locking hydraulic cylinder, steel cable hydraulic cylinder, peristaltic hydraulic cylinder and compound hydraulic cylinder. 4. High performance and variety. 5. Energy saving and corrosion resistance.

With the development and application of computer technology, the strength of hydraulic cylinder is calculated by finite element method. But compared with the mechanical transmission parts, the structure and strength design theory of hydraulic cylinder is lagging behind. In the design of hydraulic cylinder, some common basic formula is not reasonable, can only be used for rough calculation. Sometimes conservative calculation method is adopted, or a larger safety factor is taken to make up for some shortcomings in the calculation. For example, when checking the stability of the hydraulic cylinder, it is conservative to regard the hydraulic cylinder as an integral bar with equal sectional area and directly refer to euler's formula for calculation, resulting in increased material consumption, volume and weight. On the hydraulic cylinder stress estimation is insufficient, although the selected safety factor is larger, still inevitable unsafe situation. Therefore, to further improve the computer automatic design and check of hydraulic cylinder remains to be studied and developed.

High pressure is one of the main trends in the development of hydraulic cylinders. At present, the larger working pressure of hydraulic cylinder has exceeded 14OMPa. High pressure is an effective method to reduce the radial dimension of hydraulic cylinder. A 30 ton press with a working pressure of 70MPa can be made as delicate as a bench drill. 2000-3000 tons of hydraulic machine if the use of 100MPa above the ultra-high pressure hydraulic cylinder, than the ordinary high pressure hydraulic machine can reduce the weight of 1/2~2/3. The industry has maintained rapid growth for many years, has formed a relatively mature supply and demand chain, with a larger market size. According to the data, the sales revenue of China's hydraulic cylinder industry increased from 3.1 billion yuan in 2005 to nearly 11 billion yuan in 2010, with a five-year compound growth rate of 28.83%. However, and the same hydraulic industry, the proportion of oil cylinder in the national industrial output value is still low, far lower than the level of foreign developed countries.