毕业设计（论文）外文文献翻译
译文题目 Hydraulic System
专 业机械设计制造及其自动化 班 级 09机制一班
姓 名 汪康 学 号 *************
指导教师 王霞
机械工程学院
Hydraulic System
There are only three basic methods of transmitting power：Electrical，mechanical．and fluid power．Most applications actually u a combination of the three methods to obtain the most efficient overall system．To properly determine which principle method to u。it is important to know the salient features of each type．For example，fluid systems call transmit power more economically Over greater distances than Can mechanical types．However。fluid systems are restricted to shorter distances than are electrical systems．
Hydraulic transmission there are many outstanding advantages, it is widely ud, such as general industrial u of plastics processing machinery, the pressure of machinery, machine tools, etc.; operating machinery engineering machinery, construction machinery, agricultural machinery, automobiles, etc.; iron and steel industry metallurgical machinery, lifting equipment, such as roller adjustment device; civil water projects with flood control and dam gate devices, bed lifts installations, bridges and other manipulation of institutions; speed turbine power plant installations, nuclear power plants, etc.; ship from the deck heavy machinery (winch), the bow doors, bulkhead valve, stern thruster, etc.; special antenna technology giant with control devices, measurement buoys, movements
such as rotating stage; military-industrial control devices ud in artillery, ship anti- rolling devices, aircraft simulation, aircraft retractable landing gear and rudder control devices and other devices.
The role of the hydraulic system to increa the force by changing the pressure. A hydraulic system is good or bad depends on the system design is reasonable, the merits of the performance system components, system, pollution prevention and treatment, while the last point is particularly important. In recent years, China's domestic hydraulic technology has greatly improved, not simply using hydraulic technology from abroad for processing.
A complete hydraulic system consists of five parts, namely, power components, the implementation of components, control components, auxiliary components (Annex) and the hydraulic oil.
The role of dynamic components is the original motivation of the mechanical energy into fluid pressure energy, the hydraulic system of pumps, which provide power to the entire h
ydraulic system. Structures of hydraulic pumps generally have gear pumps, vane pumps and piston pumps.
Implementation of components (such as hydraulic cylinders and hydraulic motors) is to pressure the liquid can be converted to mechanical energy to drive the load for a linear reciprocating movement or rotational movement.
Control components in the hydraulic system control and regulation of fluid pressure, flow and direction. According to the different control functions, hydraulic valves can be divided into pressure control valves, flow control valves and directional control valve. Pressure control valve is divided into benefits flow valve (safety valve), pressure relief valve, quence valve, pressure switch, etc.; flow control valves including throttle, adjusting valves, flow diversion valve asmbly; Directional control valve includes a check valve, check valve, shuttle valve, valve and so on. Under the control of different ways, hydraulic valves can be divided into switching control valves, control valves and the fixed value proportional control valve.
Auxiliary components, including fuel tanks, filters, tubing and pipe joints, als, quick couplings, high pressure ball valve, ho asmbly, pressure fittings, pressure gauge, oil level, oil temperature meter and so on.
Hydraulic system of hydraulic oil is the work of the energy transfer medium, a variety of mineral oil, emulsion, oil hydraulic molding Hop categories
The role of the hydraulic system is to help humanity work. Mainly by the implementation of components to rotate or pressure into a reciprocating motion.
Hydraulic principle ：It consists of two cylinders of different sizes and composition of fluid in the fluid full of water or oil. Water is called "hydraulic press"; the said oil filled "hydraulic machine." Each of the two liquid a sliding piston, if the increa in the small piston on the pressure of a certain value, according to Pascal's law, small piston to the pressure of the pressure through the liquid pasd to the large piston, piston top will go a long way to go. Bad cross-ctional area of the small piston is S1, plus a small piston in the downward pressure on the F1. Thus, a small piston on the liquid pressure to P = F1/SI, Can be the s
ame size in all directions to the transmission of liquid. "By the large piston is also equivalent to the inevitable pressure P. If the large piston is the cross-ctional area S2, the pressure P on the piston in the upward pressure generated F2 = PxS2 Cross-ctional area is a small multiple of the piston cross-ctional area. From the type known to add in a small piston of a smaller force, the piston will be in great force, for which the hydraulic machine ud to suppress plywood, oil, extract heavy objects, such as forging steel.
The cret of hydraulic systems success and widespread u is its versatility and manageability．Fluid power is not hindered by the geometry operations when the potential difference between the tool and the work piece is sufficiently high, a transient spark discharges through the fluid, removing a very small amount of metal from the work piece of the machine as is the ea in mechanical systems．Also，power can be transmitted in almost limitless quantities becau fluid systems are not so limited by the physical 1imitations of materials as are the electrical systems．For example，the performance of an electromagnet is limited by The saturation limit of steel．On the other
hand，the power limit of fluid systems is 1imited only by the strength capacity of the material．
Industry is going to depend more and more on automation in order to increa productivity．This includes remote and direct control of production operations，manufacturing process。and materials handling．Fluid power is the muscle of automation becau of advantages in the following four major categories．
