浅谈如何处理液压传动系统泄漏故障外文文献翻译@中英文翻译@外文翻译

邵阳学院毕业设计（ 翻译译文 ） 1 How to deal with leaking hydraulic system failure Abstract： Leakage of hydraulic drive system is a mechanical failure of one of the most common in the hydraulic transmission.The working fluid leakage is a problem that can not be ignored, if the leakage can not be resolved, not only affects the system performance, damage to hydraulic components and will waste resources and pollute the environment, but aslo pose a threat to the safety in production. The sealing mechanism of the paper, an analysis of the leakage of hydraulic transmission and the reasons for the form of proposed measures to control leakage. 1, The leakage of hydraulic The work of the hydraulic fluid system is in hydraulic components (including pipelines) of the cavity flow or temporary capacity.The cycle should be limited to the work of the required liquid capacity of the cavity, but because of the pressure of space, such as a variety of reasons, there partial liquid capacity more than cavity outflow boundary, the liquid cross-border outflow phenomenon known as leakage. 2, The type and form of leakage Leakage divide into the inside and outside of the leakage. Leakage is defined as within the internal components little hydraulic fluid leakage from the high-pressure chamber to the low pressure cavity, such as hydraulic oil from the high-pressure chamber in the low-pressure chamber to leak; pressure from the valve to the back-channel leakage of oil and other channels. Leakage is defined as little outside liquid leaking out from the internal components. Such as the gear pump face leakage; penetration, such as hydraulic oil. Leakage of the hydraulic system mainly include gap leakage, leakage porous, adhesion, such as leakage and power leakage of several forms. Out of control leakage, it will bring about: system pressure is not high transfer; the speed of executing agency instability; system heat; components of low volumetric efficiency; energy, waste oil; caused by failure to control; caused fires. 3, Leakage analysis Generally speaking ， hydraulic leakage to the reasons not only for design, manufacturing problems, but also the maintenance of equipment, maintenance and other issues. Leakage in practice is very complex, and often a variety of reasons and a variety of comprehensive, but most of the hydraulic system leak caused by the failure of the seal. 邵阳学院毕业设计（ 翻译译文 ） 2 4, Sealing mechanism So far, the mechanism for sealing the exploration and interpretation, there are many schools of thought. On the seal, the more convincing one can be confirmed by the experimental results is that LHore et al study and the pumps to learn the effect model. The theory that was sealing the surface tension of liquid to help prevent leakage, the system can be sealed to ensure that the contact area of the oil film lubrication in the mixed state of the work, the sealing film is the pump Jiqing achievable. In other words, in the functioning of the process ,the sealing mechanism of seals by the seal lip will continue to pump oil absorbed from the atmosphere side to the oil side. From the sealing mechanism,we can see that seals have been sealed to ensure that surplus capacity is an important indicator of performance. Tight excessive or too small will cause seal leakage. In actual useage in many cases lead to surplus capacity had changed, resulting in seal failure. Damage to seals is mainly contaminated by the liquid, failure or defects in the groove and the sealing surface caused by improper use. Hydraulic seal failure in the form of four categories: excessive wear and tear, out of the phenomenon of deformation and system damage caused by air. 4.1 Excessive wear is excessive wear and tear damage to seals, one of the main performance. Excessive wear can occur in various ways. As a result of seal materials normally used in rubber products, poor surface finish or abrasive rubber will have a tear on the role of accelerated wear and tear. 4.2 When the seals above the recommended pressure, out of work is the sealing part of the roots to strengthen the force was due to wear out. Out of the reasons for the phenomenon, usually as a result of seal groove and seal extrusion gap size error caused by caused by too much. In addition, as a result of too high temperature will soften the rubber so that it can squeeze into the room temperature than can squeeze into the gap in smaller. 4.3 Generally, deformation of seals is due to deformation caused by improper installation. Installed, if too much pressure and tension, it will cause the plastic deformation occurred seals, shrink the volume change, thus affect the sealing performance, which is common hydraulic failure in one of the leakage. 4.4 Air system damage caused by liquid sealing of the sealed lips after the bubble, the bubble is compressed to a fraction of the original size. When the bubbles reach the seals of the non-pressure side, they release energy quickly, so quickly sealed lips damaged, showing a unique flared axial groove. 4.5 The impact of several important factors in leakage of hydraulic system in the practical work, the following factors have had a significant impact on the leakage: The working pressure and 邵阳学院毕业设计（ 翻译译文 ） 3 temperature rise. The higher the pressure of hydraulic system leaks more easily.When the work of sealing pressure more than the normal pressure, the sealing lip easily deformation occurred in the middle of depression, thereby increasing the width of the contact. Practice shows that when the pressure increases from zero to 0.1MPa, the contact pressure on the width of zero will be 4 times. Under pressure to increase the width of contacts so that the increase of friction torque, also increased wear and tear, temperature increased, the leakage increase, thereby affecting the service life of seals. High oil temperature, oil film thinning, increased friction, wear and tear aggravated by rapid aging of sealing materials to harden brittle, and may soon lead to leakage. As the oil temperature increased, the seal will be a sharp decline in life expectancy, increase in temperature 10 , seal life will be shortened by about 1 / 3. Speed. Speed not only affect the speed axis to seal the leak, and as a result of changing speed, will cause the temperature rise, such as dynamic load changes, which seriously affect the work of seal life. Cleanliness of the working media. Hydraulic system of hydraulic medium is oil, if oil is dirty, or as a result of mechanical operation of the components produced in the powder and chip wear powder, as well as the external intrusion of dust.Once into the oil, oil quality will deteriorate shaped the formation of sludge and solid impurities, arising from the mouth and lips sealed components scratched the surface, resulting in rapid seal wear, leakage increases. The work of medium viscosity and rubber materials. As the rubber seal on the oil with a variety of different affinity, and thus there will be expansion or contraction of rubber, in general, the lower viscosity medium work, the more easy to leak, the more difficult the higher the leakage. 5 Strategies In order to control the leakage of the hydraulic system, it is necessary to detect, correct selection and use of seals, such as start. 5.1,Hydraulic leakage detection system to diagnose the reasons for the leakage, which is the key to control leakage. 5.2,Selection of the correct seals in most sealed or easily deformed flexible material, sealing material is to determine the correct choice of sealing performance, the main factors which are used to prevent leakage.Sealing materials shuld meet the general requirements: resistance to erosion of the work of medium capacity, long-term changes in the work of small size and hardness; flexibility and good compression recovery, permanent deformation small; material sensitivity, and not leaking; the appropriate mechanical strength and hardness; the sealing surface with a paste containing the softness and flexibility; resistant to low temperature and high temperature performance and do not break down 邵阳学院毕业设计（ 翻译译文 ） 4 under high temperature and does not soft, do not hard at low temperatures; not corrosion, but also non-stick surface on the metal; resistant to ozone and good anti-aging, durable; processing convenience, low prices. Any kind of material often can not fully meet these requirements, the use should be based on working conditions, requested to choose. 5.3, Installation seals to make a reliable seal, long life, in designing the closed tank, the compression ratio must be appropriate, not too big nor too small, too large compressive stress is increased, friction increased to speed up the seal wear, also easy to distort the damage, shorten the life span of the difficulties sometimes caused by the assembly; the closed tank is too small, then seal is easy to leak. Parts should be oriented design angle, so as not to damage seal assembly. Installation try to avoid too much tension, so as to avoid deformation. Special attention need to ensure the sealing of the mouth lips face perpendicular to the axis of the center line, otherwise the shift would have resulted in a partial unilateral lip wear and tear and can not be formed the absorbed pump. 5.4 Note in the actual work Control the oil temperature in the hydraulic system. High oil temperature, oil film thinning, increased friction, wear and tear aggravated by rapid aging of sealing materials to harden brittle, and may soon lead to leakage. Hydraulic system pipe joints should be minimized, according to statistics, 30% 40% of the leakage in the pipe joint. Therefore we should choose the appropriate structure of the pipe connection. Hydraulic systems are commonly used pipe-expanding type, card sets and three types of welding-type. Three joints have their own characteristics, should be based on the reliability and economy of work to choose. Select the appropriate hydraulic components.The hydraulic components should improve the accuracy of the surface components. If the system does not require fast switching, wet solenoid valve should be chosen because of its longevity, the impact of small, non-dynamic seal put department to eliminate the leakage caused by putting the site. Easy access to dust. Dust seals hydraulic components or parts, the increase in dust blocking devices such as dust ring, dust cover, such as block. Equipment prevent over-pressure and ultra-long speed run. Keep the oil clean.Oil should chang regularly. 6 Conclusion Leakage of the hydraulic system have various forms.There are a variety of reasons, but mostly caused by seal failure. Therefore, the analysis of hydraulic seal failure, and take effective measures to control leakage of hydraulic technology in the promotion of practical work to play a greater role of great significance. 邵阳学院毕业设计（ 翻译译文 ） 5 1浅谈如何处理液压传动系统泄漏故障 摘要 ： 液压传动系统泄漏是机械最常见的故障之一，在液压传动中，工作液体的泄漏是一个不可忽视的问题，如果泄漏得不到解决，不仅影响系统的工作性能，损坏液压元件，而且会浪费资源，污染环境，对安全生产造成威胁。该文通过对密封机理的研究，分析了液压传动的泄漏形式及原因，提出控制泄漏的措施。 1、液压传动的泄漏 液压系统中的工作液体，是在液压元件（包括管道）的容腔内流动或暂存的，循环的工作液体理应限于在规定的容腔 内，然而由于压力、间隙等种种原因，有部分液体超过容腔边界流出，液体的“越界流出”现象称为泄漏。 2、泄漏的类型与形式 泄漏分为内泄漏和外泄漏。内泄漏是指液压元件内部有少量液体从高压腔泄漏到低压腔，如液压传动中油液从高压腔向低压腔的泄漏；从换向阀内压力通道向回油通道的泄漏等。外泄漏是指少量液体从元件内部向外泄漏。如齿轮泵的端面泄漏；液压油管的渗透等。液压系统的泄漏主要有缝隙泄漏、多孔隙泄漏、粘附泄漏和动力泄漏等几种形式。泄漏得不到控制，将会造成：系统压力调不高；执行机构速度不稳定；系统发热；元件容积效率低；能 量、油液浪费；造成控制失灵；引起火灾等。 3、泄漏原因分析 一般来说液压传动中产生泄漏的原因有设计、制造方面的问题，也有设备维护、保养等方面的问题。在实际中泄漏情况是很复杂的，往往是各种原因和种种情况的综合，但液压系统中泄漏大部分是由密封失效引起的。 4、密封机理 迄今为止，对密封机理的探索和解释存在着许多学派。就密封而言，其中比较有说服力、并经实验结果得以证实的，是 L Hore 等人研究并提出的“泵汲”效应模型理论。该理论认为被密封液体的表面张力有助于防止泄漏，可保证密封系统中接触区的油液膜处于混合润滑状态 下工1 Ji Guangguo et. Hydraulic system fault diagnosis and rule out the M Beijing: Ocean Publishing .1992. 邵阳学院毕业设计（ 翻译译文 ） 6 作，其密封是通过油膜的“泵汲”实现的。也就是说，密封件的密封机理是由密封唇部，在运转过程中不断地将油液从大气侧泵汲到油侧。从密封机理可知，密封件过盈量是保证密封性能的一个重要指标。过盈量过大或过小都会造成密封泄漏。在实际使用中有许多情况会引起过盈量改变，从而导致密封失效。密封件的损坏主要是由被污染的液体、不合格的沟槽或有毛病的密封表面及使用不当所引起的。液压传动中密封失效形式主要有四类：过度磨损、挤出现象、变形和系统中的空气所引起的损坏。 4.1 过度磨损过度磨损是密封件损坏的主要表现之一。过度磨损可以各 种方式发生。由于密封件所用材料一般为橡胶产品，表面光洁度差或有磨粒都会对橡胶产生撕裂作用，使磨损加速。 4.2 挤出现象当密封件工作在高于推荐的工作压力时，密封根部的加强部分由于受力而被磨损掉。挤出现象出现的原因，一般都是由于密封沟槽和密封件尺寸偏差造成挤出间隙过大引起的。另外，由于温度过高会使橡胶软化，使它能挤入比常温下所能挤入的更小缝隙中。 4.3 变形密封件变形一般是由于安装不当而造成的。安装时，如果过分地压入和张紧，就会使密封件发生塑性变形，过盈量发生变化，从而影响密封性能，这也是液压传动中泄漏常见故障之一。 4.4 系统中的空气引起密封的损坏液体中的气泡经过密封唇边时，气泡被压缩为原来尺寸的几分之一。当这种气泡到达密封件的非压力侧时，便迅速释放出能量，使密封唇边迅速破损，呈现出特有的“喇叭形”轴向沟槽。 4.5 影响泄漏的几个重要因素液压系统在实际工作中，下面几个因素对泄漏有重要影响：工作压力和温升。液压系统压力越高越易泄漏。当工作压力大于密封耐压时，密封唇部易变形，中间发生凹陷，从而增大了接触宽度。实践表明，当压力从零增大到 0.1MPa 时，其接触宽度将是压力为零时的 4