Today, hydraulic systems are widely used in various industries and machinery. As a transmission technology, hydraulic mode than the traditional mechanical methods, has the following advantages: 1, can produce great force, and easy to control; 2, in a wide range of continuously variable speed; 3, it is easy to prevent overload, Safety; 4, the size of small output, the installation location can be freely selected; 5, the output force of the control simple and accurate, remote control. Although the hydraulic system has the above advantages, but its automatic reciprocating system has not been able to effectively and reliably solve. Many devices in many industries, such as mud pumps in geological drilling equipment, high pressure pumps in desalination plants, fire pumps for high-rise buildings, etc., require continuous output of high pressure, high flow fluid media, System automatically reciprocates the problem, still using the traditional mechanical methods, resulting in its bulky equipment, energy consumption and low efficiency. The project "hydraulic automatic reciprocating cylinder" is a national utility model patent, successfully solved the hydraulic system automatically reciprocating problem, making the above equipment using hydraulic technology to become a reality. The technology is the hydraulic system of the main actuator - cylinder redesign, auxiliary to the external control valve to achieve automatic cylinder reciprocating, and reliable, simple structure, low cost. Applications 1, geological drilling hydraulic mud pump existing mud pump is the use of motor driven crankshaft, connecting rod to promote the piston output of mud. This kind of structure has been used for many years and is backward in technology. As a result, the volume of the mud pump is large, the output pressure of the mud fluctuates, the flow rate is unstable, and the maximum power of the mud pump is limited. Generally, the pressure can only reach 3 ~ 4Mpa. The hydraulic mud pump manufactured by using the patented technology has the volume of the mud pump being only 1/2 to 1/3 of that of the existing mud pump at the same output power and the energy consumption is about 80% of that of the existing mud pump. Although the manufacturing costs slightly increased, but the hydraulic mud pump design without power constraints, the output pressure can reach tens of Mpa, unlimited flow expansion, and the output pressure and flow stability. 2, desalination of the hydraulic high-pressure pump using reverse osmosis technology is a high efficiency, easy-to-large-scale use of desalination technology, water shortage in today, has broad application prospects. High-pressure pump is reverse osmosis desalination technology in the application of a key equipment. The existing high-pressure pump is basically a mechanical structure. Common types of pumps are single-stage, high-speed centrifugal pumps, piston pumps and multistage centrifugal pumps. Usually, single-stage centrifugal pumps have the lowest efficiency and the plunger pump has the highest efficiency. In large systems, multistage centrifugal pumps are often used. In China, there is no professional manufacturer of desalination high pressure pump. The main reason is that in order to achieve high efficiency in high-pressure pumps, some important components must be processed to a high degree of machining precision, which requires very specialized and expensive processing equipment and a large processing cost. Therefore, the price of imported high-pressure pump is very high. Hydraulic automatic reciprocating cylinder high pressure pump, compared with the mechanical high-pressure pump, piston pump has greatly improved work efficiency, high power is very easy to achieve. Compared with the imported similar products, the greater the pump power, the lower the cost of production, the greater the magnitude of its price decline. 3, high-pressure cleaning equipment 4, high-rise building water supply (fire pump) In short, automatic reciprocating hydraulic system, broaden the scope of the hydraulic system, making the hydraulic system to efficient, flexible, high-power, low cost advantage to be more play , The application will bring tremendous economic and social benefits to the enterprise.