Hydraulic systems change power from one form to another. This process is accomplished by using a closed liquid as a medium. A science that processes the transfer of force or motion through a closed liquid is called hydraulics, which comes from the Greek word “hydros”, it means water. The science of hydraulics is a young science—only centuries old. It began with the hydraulic lever drive principle discovered by a man named Bryce Pascal. This principle was later called Pascal's Law. Pascal made the discovery, but it was another man named Joseph Blam who made the hydraulic press in 1795 for the first time. The liquid used as a medium in this hydraulic press is water.
After World War I (1914-1918), hydraulic transmission was widely used, Especially after 1920, The development is more rapid. Hydraulic components in the late 19th century ,20th century, Only then began to enter the formal industrial production stage. And in 1925 F.Vikers invented a pressure - balanced vane pump, For the modern hydraulic components industry or hydraulic transmission gradually established a foundation. A theoretical and practical study of energy fluctuation transfer by G•Constantimsco in the early 20th century; Contribution to hydraulic transmission (hydraulic coupling, torque converter, etc.) in 1910, These two areas have been developed.
World War II (1941-1945), Hydraulic transmission is used in 30% of American machine tools. It should be noted that, The development of Japanese hydraulic transmission is nearly 20 years later than that of Europe and America. Around 1955, Rapid development of hydraulic transmission in Japan, In 1956, the "Hydraulic Industry Association ". For nearly 20~30 years, The rapid development of Japanese hydraulic transmission, Leading the world. Hydraulic transmission has many outstanding advantages, So it's widely used, Such as general industrial plastic processing machinery, pressure machinery, machine tools; Construction machinery, construction machinery, agricultural machinery, automobiles, etc; Metallurgical machinery, lifting device, roll adjusting device, etc. used in steel industry; Flood gate and dam device, river bed lifting device, bridge control mechanism, etc; Power plant turbine speed regulating device, nuclear power plant and so on; Deck lifting machinery (winch), bow door, bulkhead valve, stern thruster, etc; Giant antenna control device for special technology, measuring buoy, lifting and rotating stage, etc; Artillery control device, ship anti-roll device, aircraft simulation, aircraft landing gear retractable device and rudder control device for military industry.