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1、精选优质文档-倾情为你奉上Hydraulic SystemHydraulic presser drive and air pressure drive hydraulic fluid as the transmission is made according to the 17th century, Pascals principle of hydrostatic pressure to drive the development of an emerging technology, the United Kingdom in 1795 Braman Joseph (Joseph Braman
2、 ,1749-1814), in London water as a medium to form hydraulic press used in industry, the birth of the worlds first hydraulic press. Media work in 1905 will be replaced by oil-water and further improved.After the World War I (1914-1918) ,because of the extensive application of hydraulic transmission,
3、espec- ially after 1920, more rapid development. Hydraulic components in the late 19th century about the early 20th century, 20 years, only started to enter the formal phase of industrial production. 1925 Vickers (F. Vikers) the invention of the pressure balanced vane pump, hydraulic components for
4、the modern industrial or hydraulic transmission of the gradual establishment of the foundation. The early 20th century G Constantimscofluct- uations of the energy carried out by passing theoretical and practical research; in 1910 on the hydraulic trans- mission (hydraulic coupling, hydraulic torque
5、converter, etc.) contributions, so that these two areas of develo- pment.The Second World War (1941-1945) period, in the United States 30% of machine tool applications in the hydraulic transmission. It should be noted that the development of hydraulic transmission in Japan than Europe and the United
6、 States and other countries for nearly 20 years later. Before and after in 1955, the rapid development of Japans hydraulic drive, set up in 1956, Hydraulic Industry. Nearly 20 to 30 years, the development of Japans fast hydraulic transmission, a world leader.Hydraulic transmission There are many out
7、standing advantages, it is widely used, such as general industr- ial use of plastics processing machinery, the pressure of machinery, machine tools, etc.; operating machinery engineering machinery, construction machinery, agricultural machinery, automobiles, etc.; iron and steel indu- stry metallurg
8、ical machinery, lifting equipment, such as roller adjustment device; civil water projects with flo- od 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
9、machinery (winch), the bow doors, bulkhead valve, stern thruster, etc.; special antenna technology giant with control devices, measu- rement buoys, movements such as rotating stage; military-industrial control devices used in artillery, ship anti- rolling devices, aircraft simulation, aircraft retra
10、ctable landing gear and rudder control devices and other devi- ces.A complete hydraulic system consists of five parts, namely, power components, the implementation of co- mponents, control components, auxiliary components and hydraulic oil. The role of dynamic components of the original motive fluid
11、 into mechanical energy to the pressure that the hydraulic system of pumps, it is to power the entire hydraulic system. The structure of the form of hydra- ulic pump gears are generally pump, vane pump and piston pump. Implementation of components (such as hydraulic cylinders and hydraulic motors) w
12、hich is the pressure of the liquid can be converted to mechanical energy to drive the load for a straight line reciprocating movement or rotational movement. Control components (that is, the various hydraulic valves) in the hydraulic system to control and regulate the pressure of liquid, flow rate a
13、nd direction. According to the different control functions, hydraulic pressure control valve can be divided into valves, flow control valves and directional control valve. Pressure control valves are divided into benefits flow valve (safety valve), pressure relief valve, sequence valve, pressure rel
14、ays, etc.; flow control valves including throttle, adjusting the valves, flow diversion valve sets, etc.; directional control valve includes a one-way valve , one-way fluid control valve, shuttle valve, valve and so on. Under the control of different ways, can be divided into the hydraulic valve con
15、trol switch valve, control valve and set the value of the ratio control valve. Auxiliary components, including fuel tanks, oil filters, tubing and pipe joints, seals, pressure gauge, oil level, such as oil dollars. Hydraulic oil in the hydraulic system is the work of the energy transfer medium, ther
16、e are 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 system and hydraulic power control signal is composed of t
17、wo parts, the signal control of some parts of the hydraulic power used to drive the control valve movement. Part of the hydraulic power means that the circuit diagram used to show the different functions of the interrelationship between components. Containing the source of hydraulic pump, hydraulic
18、motor and auxiliary components; hydraulic control part contains a variety of control valves, used to control the flow of oil, pressure and direction; operative or hydraulic cylinder with hydraulic motors, according to the actual requirements of their choice.In the analysis and design of the actual t
19、ask, the general block diagram shows the actual operation of equi - pment. Hollow arrow indicates the signal flow, while the solid arrows that energy flow. Basic hydraulic circuit of the action sequence - Control components (two four-way valve) and the spring to reset for the implementation of compo
20、nents (double-acting hydraulic cylinder), as well as the extending and retracting the relief valve opened and closed . For the implementation of components and control components, presentations are based on the corresponding circuit diagram symbols, it also introduced ready made circuit diagram symb
21、ols. Working principle of the system, you can turn on all circuits to code. If the first implementation of components numbered 0, the control components associated with the identifier is 1. Out with the implementation of components corresponding to the identifier for the even components, then retrac
22、ting and implementation of components corresponding to the identifier for the odd components. Hydraulic circuit carried out not only to deal with numbers, but also to deal with the actual device ID, in order to detect system failures.DIN ISO1219-2 standard definition of the number of component compo
23、sition, which includes the following four parts: device ID, circuit ID, component ID and component ID. The entire system if only one device, device number may be omitted. Practice, another way is to code all of the hydraulic system components for numbers at this time, components and component code s
24、hould be consistent with the list of numbers. This method is particularly applicable to complex hydraulic control system, each control loop are the corresponding number with the systemWith mechanical transmission, electrical transmission compared to the hydraulic drive has the following advantages:
25、1, a variety of hydraulic components, can easily and flexibly to layout. 2, light weight, small size, small inertia, fast response. 3, to facilitate manipulation of control, enabling a wide range of stepless speed regulation (speed range of 2000:1). 4, to achieve overload protection automatically. 5
26、, the general use of mineral oil as a working medium, the relative motion can be self-lubricating surface, long service life; 6, it is easy to achieve linear motion / 7, it is easy to achieve the automation of machines, when the joint control of the use of electro-hydraulic, not only can achieve a h
27、igher degree of process automation, and remote control can be achieved. The shortcomings of the hydraulic system: 1, as a result of the resistance to fluid flow and leakage of the larger, so less efficient. If not handled properly, leakage is not only contaminated sites, but also may cause fire and
28、explosion. 2, vulnerable performance as a result of the impact of temperature change, it would be inappropriate in the high or low temperature conditions. 3, the manufacture of precision hydraulic components require a higher, more expensive and hence the price. 4, due to the leakage of liquid medium
29、 and the compressibility and can not be strictly the transmission ratio. 5, hydraulic transmission is not easy to find out the reasons for failure; the use and maintenance requirements for a higher level of technology.In the hydraulic system and its system, the sealing device to prevent leakage of t
30、he work of media within and outside the dust and the intrusion of foreign bodies. Seals played the role of components, namely seals. Medium will result in leakage of waste, pollution and environmental machinery and even give rise to malfunctioning machinery and equipment for personal accident. Leaka
31、ge within the hydraulic system will cause a sharp drop in volumetric efficiency, amounting to less than the required pressure, can not even work. Micro-invasive system of dust particles, can cause or exacerbate friction hydraulic component wear, and further lead to leakage. Therefore, seals and seal
32、ing device is an important hydraulic equipment components. The reliability of its work and life, is a measure of the hydraulic system an important indicator of good or bad. In addition to the closed space, are the use of seals, so that two adjacent coupling surface of the gap between the need to con
33、trol the liquid can be sealed following the smallest gap. In the contact seal, pressed into self-seal-style and self-styled self-tight seal (ie, sealed lips) two.The three hydraulic system diseases 1, as a result of heat transmission medium (hydraulic oil) in the flowvelocity in various parts of the
34、 existence of different, resulting in theexistenceof a liquid within the internal friction of liquids and pipelines at the sam- etime there is friction between the inner wall, which are a result of hydraulic thereasons for the oil tempera- ture. Temperature will lead to increased internaland externa
35、l leakage, reducing its mechanical efficiency. At the same time as aresult of high temperature, hydraulic oil expansion will occur, resulting inincreased com- pression, so that action can not be very good control oftransmission. Solution: heat is the inherent characte -ristics of the hydraulicsystem
36、, not only to minimize eradication. Use a good quality hydraulic oil,hydraulic piping arrangement should be avoided as far as possible theemergence of bend, the use of high-quality pipe and fittings, hydraulic valves,etc.2, the vibration of the vibration of the hydraulic system is also one of its ma
37、laise. As a result of hydraulic oil in the pipeline flow of high-speed impact and the control valve to open the closure of the impact of the process are the reasons for the vibration system. Strong vibration control action will cause the system to error, the system will also be some of the more soph
38、isticated equipment error, resulting in system failures. Solutions: hydraulic pipe should be fixed to avoid sharp bends. To avoid frequent changes in flow direction, can not avoid damping measures should be doing a good job. The entire hydraulic system should have a good damping measures, while avoi
39、ding the external local oscillator on the system.3, the leakage of the hydraulic system leak into inside and outside the leakage leakage. Leakage refers to the process with the leak occurred in the system, such as hydraulic piston-cylinder on both sides of the leakage, the control valve spool and va
40、lve body, such as between the leakage. Although no internal leakage of hydra- ulic fluid loss, but due to leakage, the control of the established movements may be affected until the cause system failures. Outside means the occurrence of leakage in the system and the leakage between the external envi
41、ronment. Direct leakage of hydraulic oil into the environment, in addition to the system will affect the working environment, not enough pressure will cause the system to trigger a fault. Leakage into the enviro- nment of the hydraulic oil was also the danger of fire. Solution: the use of better qua
42、lity seals to improve the machining accuracy of equipment. Another: the hydraulic system for the three diseases, it was summed up: fever, with a father拉稀 (This is the summary of the northeast people). Hydraulic system for the lifts, excavators, pumping station, dynamic, crane, and so on large-scale
43、industry, construction, factories, enterprises, as well as elevators, lifting platforms, Deng Axle industry and so on. Hydraulic components will be high-performance, high-quality, high reliability, the system sets the direction of development; to the low power, low noise, vibration, without leakage,
44、 as well as pollution control, water-based media applications to adapt to environmental requirements, such as the direction of development; the development of highly integrated high power density, intelligence, mechatronics and micro-light mini-hydraulic components; active use of new techniques, new
45、 materials and electronics, sensing and other high-tech.- Hydraulic coupling to high-speed high-power and integrated development of hydraulic transmission equ- ipment, development of water hydraulic coupling medium speed and the field of automotive applications to develop hydraulic reducer, improve
46、product reliability and working hours MTBF; hydraulic torque converter to the development of high-power products, parts and components to improve the manufacturing process tech -nology to improve reliability, promote computer-aided technology, the development of hydraulic torque con- verter and powe
47、r shift transmission technology supporting the use of ; Clutch fluid viscosity should increase the quality of products, the formation of bulk to the high-power and high-speed direction. Pneumatic Industry:- Products to small size, light weight, low power consumption, integrated portfolio of developm
48、ent, the implementation of the various types of components, compact structure, high positioning accuracy of the direction of development; pneumatic components and electronic technology, to the intelligent direction of development; component performance to high-speed, high-frequency, high-response, h
49、igh-life, high temp- erature, high voltage direction, commonly used oil-free lubrication, application of new technology, new technology and new materials.(1) used high-pressure hydraulic components and the pressure of continuous work to reach 40Mpa, the maximum pressure to achieve instant 48Mpa; (2) diversification of regulation and control; (3) to further improve the regulation performance, increase the efficie