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1. What is hydraulic?
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A complete hydraulic system consists of five parts, namely, power components, actuators, control components, no parts and hydraulic oil. Is the role of dynamic components can prime mover's mechanical energy is converted into liquid pressure, refers to the oil pump in the hydraulic system, it is to power the entire hydraulic system. The structure of hydraulic pump generally have gear pump, vane pump and piston pump. Executive components (such as hydraulic cylinders and hydraulic motors) role is to liquid pressure can be converted to mechanical energy, to drive the load for a straight line reciprocating movement or rotational motion. Control components (that is, the various hydraulic valves) in the hydraulic system to control and adjust the liquid pressure, flow and direction. According to the different control functions, hydraulic valve can be divided into the village of force control valve, flow control valves and direction control valves. Pressure control valve is divided into benefits flow valve (safety valve), pressure reducing valve, sequence valve, pressure relays, etc.; Flow control valves including collecting valve throttle valve, adjusting valve, tap, etc.; Direction control valves including check valve, hydraulic control one-way valve, shuttle valve, reversing valve, etc. According to different control mode, control valve, hydraulic valve can be divided into the switch type constant value control valve and proportional control valve. Auxiliary components including oil tank, oil filter, oil pipe and tube joint, seal, pressure gauge, oil level, oil temperature gauge, etc. Hydraulic oil is the working medium of transmit energy in hydraulic system, there are all sorts of mineral oil, emulsion and molding hydraulic oil and so on several major categories.3829
The principle of hydraulic
It is composed of two different sizes of hydraulic cylinder, the cylinder filled with water or oil. Water filling is called "press"; Oil-filled says "press". Two has a sliding in each cylinder piston, if add certain values in the small piston pressure, according to PASCAL's law, the piston will be big pressure by liquid pressure is transmitted to the piston, the piston top. A small cross-sectional area of the piston is S1, added to downward pressure on the small piston is F1. So the small piston of liquid pressure is P = F1 / SI, being able to size the same in all directions from a liquid transfer. "big piston pressure must also equal to P. If large cross-sectional area of the piston is S2, pressure P on the large piston upward pressure generated by the F2 = PxS2
Cross-sectional area is small piston cross-sectional area ratio. From the type, add a small force on the small piston, it got a lot of force on the piston, for this hydraulic press for pressing of plywood, oil, extract weight, forging steel, etc.
Hydraulic drive of the development
Hydraulic and pneumatic transmission called fluid drive, which is based on PASCAL hydrostatic pressure transmission principle put forward by the 17th century and developed a new technology, in 1795 the British Joseph Braman family (Joseph Braman, 1749-1814), in London's water as working medium, in the form of a hydraulic press is applied to industry, gave birth to the world's first hydraulic press. Working medium water instead of oil, in 1905 and has been further improved.
After the first world war (1914-1918), hydraulic transmission is widely used, especially after 1920, grows more rapidly. Hydraulic components for about 20 years in the late 19th century early 20th century, began to enter the formal stages of industrial production. 1925 vickers (F.V ikers) invented the vane pump pressure balance type, for modern industrial hydraulic components or hydraulic drive build laid a foundation. At the beginning of the 20th century konstantin loch grams (G • Constantimsco) fluctuations of energy transfer of theoretical and practical studies; 1910 of hydraulic drive, hydraulic coupling, hydraulic torque converter, etc.) aspects of the contribution, the developed areas of these two aspects.