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
浅谈如何处理液压传动系统泄漏故障
液压 系统 的泄漏 分 为 １ 人 Ｊ 泄漏 和外泄漏 。 内泄漏 是指
传动 中密封失效形 式 主要 有 四类 ： （ 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
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 。
综合 ， 但液 压 系 统 中泄 漏 大 部 分 是 由密 封 失 效 引 起 的。 从密封机 理可知 ， 密封 件过 盈量 是 保证 密封 性 能 的一 个
传动 的泄漏。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 和油液 浪费 ； 造成控 制失灵 ； 引起 火灾 等。
论 。该 理论 认 为 被 密 封 液 体 的 表 面 张力 有 助 于 防 止 泄
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 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 ： （ １ ） 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
数控系统辅助液压挖掘机的概念外文文献翻译、中英文翻译、外文翻译
AbstractA concept of digital control system to assist the operators of hydraulic excavators is presented and discussed. Then, control system based on described ideas was mounted on a special numerically controlled stand, equipped with D r A and A r D converters, where small hydraulic backhoe excavator K-111 fixtures were used. Experimental results shows that it fulfils all described requirements and can be used as the machine operator assist. It enables for precision tool guidance. automatic repetition of realized movements, realization of specific tool trajectories including energetically optimal path sand automatic improvement or optimization of realized paths. Tool trajectories can also be prescribed using the setting model, making excavator the machine of tele operator class. Presented system can be used as a basis for real machine control system. q 1998 Elsevier Science B.V. All rights reserved.Keywords: Digital control system; Hydraulic excavators; Tool trajectories1. IntroductionThe automation of heavy machines, including hydraulic excavators, began in mid-1970s and was possible due to invention of real time controllers and hydraulic elements with good dynamic properties. The first excavator equipped with several mechatronics systems, which was shown as a working model, was the excavator FUTURE prepared by Orenstein and Koppel for BAUMA’83 Fairs. Since that time, machines equipped with systems automating the engine operation, pumps operation, machine fixtures, machine diagnostic, etc.,are presented and offered. Such systems bring real help to the operator and clear economical profit. For example, LIEBHERRR902 excavator equipped with LITRONIC System. has for a trench digging the efficiency 40% higher and unit costs 30% lower, than similar machine without such automatic system. Although automationŽ. in some case, optimization of several machine systems develops quite fast, the main machine process—the shoving process—has no proper understanding and description until now. Its automation is quiteŽlimited to systems repeating already performed. movements, laser levelling systems, etc. and systems optimizing such processes are not developed yet. Quite new experimental results show clear idea for energetically optimal tool trajectories in the case of cohesive materials. The tool tip has to be guided along slip lines, which are generated from the tiptool during the previous stage of the shoving process. To realize such trajectories for practical purpose and real machines, it is necessary to build a special control system for the tool motion, which enables automatic realization of such trajectories as well as realization of other tasks that help the operator.2. The basic concept of the computer aided control systemItIt was shown before that analyzing the the soil deformation during the shoving process, it is possible to determine energetically optimal cutting tool trajectories. Hence, the automatic tool movement along slip lines generated in cohesive material has to be a quite important option of proposed system. It should also enable precision tool guidance, automatic repetition of already realized movementsŽ. for example, ‘teach-in’ , realization of some tool movements impossible to realize manually, etc. Taking into account to-day experience with automation of heavy machines, such system should be constructed to assist machine operator, who still plays a main decisive and control role. Hence, the proper separation of tasks, between the control sys-tem and the operator, is necessary. Such control system for excavators was built on laboratory scale. Its basic assumptions can be stat d w x Ž . as follows 13 : 1 operation of the central control system is based on cooperation of two digital systems. The first one controls directly the motion of the machine fixture using the control system of the hydraulic cylinders position. The second one worksŽ. out control signals for the first one. 2 Under the standard work conditions, action of the proportional hydraulic valves of the fixture cylinders is controlled through the computer. The direct operator control isŽ. possible only in case of emergency conditions. 3The feedback between the machine environment and control system is realized through the operator. He participates continuously in the process of the con-Ž. control of machine fixtures motion. 4 For realization of the tool motions which are impossible for manual control, the operator has a possibility to coordinate displacement of separate cylinders by means of hard-Ž. ware or software. 5 The operator has a possibility to switch into automatic control of the fixture motionto realize a special tool trajectories. For example, it can be energetically optimal tool trajectory where tool tip moves along slip lines or specific trajectoryŽ. realized and stored previously. 6 The optimal cut-ting tool trajectories can also be realized as correction of trajectories given by the operator. Such correction is done mainly during the time parametrization of the tool path. 7 The trajectories given by the operator can be corrected by the system to take in toaccount such limitations as geometrical ones, maxi-mal power of the pump, maximal output of the pump, maximal pump efficiency, etc.Presented concept is based on such cooperation between the operator and control system that the fixture movements are controlled by the operator while the control system corrects him or, when ordered, can act automatically3. Examples of the control system functioningThe control system based on described above ideas was mounted on a special numerically con-trolled stand, equipped with PC computer having CrA and ArC converters, where small hydraulicw x backhoe excavator K-111 fixtures were used 14–17 .The control system of the fixture motions utilizes the control system of the cylinder positions. The fixture cylinder displacement is controlled by the proportional hydraulic valves fed by the variable out putmultipiston pump. The control system for fixture cylinders is based on three control systems, each to control different cylinder displacement using PID or state control ler w x 14 . It enables control of the fixture motions using different methods of the tool trajectory planning, measuring of acting forces and displacements and determining other magnitudes related to the fixture movements. Experimental data acquisition is also possible. One of quite important problems, which should betaken into account when building the control system, is the way of the tool trajectory planning. It isŽ. w x realized as usually in two steps 15 . In the first one, the trajectory shape is planned and determined. In the second one, the trajectory curve is parametric zed in time in a determined manner, what defines the trajectory within the generalized coordinate space. On this basis, the time runs of the generalized coordinates describing the configuration space of the machine are determined. In the case of an excavator, lengths of hydraulic cylinders are thosecoordinates3.1. The tool moÕement along prescribed lineThe control system build for experimental standw x 15–17 enables, among others, programming the work motion in the excavator work space, or in its configuration space, using ‘point to point’ technique. In this method, the coordinates of the initial and final points, and sufficient number of the character isticnodal points, are defined. Values describing this points are then introduced to the system, where remaining points of the trajectory are calculated using interpolation methods. Linear or the third degree polynomial interpolation is used. The trajectory y parametrization in time can be realized through:–determination of the total trajectory run-time and its division into individual segments of the path. System calculates the velocities of cylinders,–determination of the run-time between following nodal points, taking into account some limitationsŽ. or conditions for optimization .In the case of standard excavator construction, it is quite difficult to precisely realize trajectories, where simultaneous movement of two or three cylinders is necessary.3.2. The tool moÕement using the setting modelalong straight lines In presented case, the coordination of the fixture cylinder movement was realized by hardware, that means using the setting model. It can also be realizedŽby software. The machine operator using special. buttons , can generate horizontal or vertical tool movement preserving the constant value of the tool cutting angle in every point of the machine working space. The prescribed tool path is stored using the point method in the configuration space. Further-more, the machine operator determines motion velocity which is corrected by control system taking in to account the feeder output. In Figs. 7 and 8, results of such control for the horizontal tool movement are shown. The cutting tool trajectory is presented in Fig. 7. In Fig. 8, the fixture cylinder lengths calculated for prescribed velocity are drawn with solid line. Their calculated lengths assumes the feed erout put are drawn with dotted line. The way of the tool path time parametrization was similar to that using the setting model. It is seen that velocities given by the operator are too high and system corrected cylinder motion timing to keep assumed feeder output. The example of the tool motion along the inclined line is presented in Figs. 9 and 10, where the tool trajectory and corresponding cylinder lengths are drawn. Such movement is realized as a sum ofŽhorizontal and vertical tool motions the line inclination depends on proportions between horizontal and. vertical velocities . For example, the tool trajectory long inclined line can be realized during theŽ. ‘withdraw’ stage of the shoving process Fig. 2 to follow the slip line or for automated, making the soil scarps.3.3. Automatic tool moÕement along a slip lineAnalysis of experimental results of the soil shoving process shows that it is possible to predict theoretically the slip lines positions and energy etically optimal tool trajectories. It can be done for homogeneous material under laboratory conditions. In real situations, when material is not homogeneous and not well-defined, the material sleep lines has to be detected automatically. The procedure of automatic slip line detection is based on the observation that when cutting tool begins to penetrate more dense material, then the in crease of the horizontal force acting on the tool is observed. Such situation takes place also when theŽtool tip moves from the slip line where material. Ž density is quite small to the virgin material material. not deformed before—behind the slip line . Hence, the observed increase of the pushing force can beused for slip line detection. Such procedure, which simplified version is described below, can berealized as follows. Cutting tool motion is realized as a sum of horizontal, vertical and rotational movements and horizontal reaction of the soil is measured and followed. Firstly, the tool moves horizontally up to the moment when the horizontal force drops, that coincides with creation of slip lines system originating from the toolŽ. end Fig. 1 . If such slip lines cannot be created as a Žresult of horizontal pushing, a special procedure for. example tool rotation can be applied. Then, tool is moved vertically by prescribed displacement valueŽand then moves again horizontally rotation of the. tool can be added up to the moment when horizontal force begins to increase. If so, , and then horizontally, and so on. This way, the tip of the tool automaticallyŽfollows in a step way the slip line. Results of such preliminary tests are presented in Figs. 11 and 12. As a simplified model, the possibility of automatic tool movement along the soil scarpinclined with 0.61 rad. was investigated. For defined values of maximum horizontal force and defined vertical displacement, the control system automatically followed the tool along the scarp. The horizontal force vs. horizontal displacement and tool trajectory are shown in Fig. 11. The magnified fragment of Fig. 11, which shows the way in which system is acting, is presented in Fig.12.4. ConclusionsExperimental results show that presented control system fulfils all described requirements and can be used as the machine operator assist. It enables for precision tool guidance, automatic repetition of realized movements, realization of specific tool trajectories including energetically optimal paths and automatic improvement or optimization of realized paths. Tool trajectories can also be prescribed using the setting model, making excavator the machine of tele operator class. Presented system can be used as abas is for real machine control system. Acknowledgements This research was sponsored by the Project KBN7T07C00412 ‘Optimization of the soil shoving process due to heavy machines of an excavator type’ realized at Kielce University of Technology.数控系统辅助液压挖掘机的概念摘要数控系统辅助液压挖掘机操作者的概念被提出和讨论。
液压系统液压传动和气压传动毕业论文中英文资料对照外文翻译文献综述
中英文资料对照外文翻译文献综述液压系统液压传动和气压传动称为流体传动，是根据17世纪帕斯卡提出的液体静压力传动原理而发展起来的一门新兴技术，1795年英国约瑟夫•布拉曼(Joseph Braman,1749-1814)，在伦敦用水作为工作介质，以水压机的形式将其应用于工业上，诞生了世界上第一台水压机。
1905年将工作介质水改为油，又进一步得到改善。
第一次世界大战(1914-1918)后液压传动广泛应用，特别是1920年以后，发展更为迅速。
液压元件大约在 19 世纪末 20 世纪初的20年间，才开始进入正规的工业生产阶段。
1925 年维克斯(F.Vikers)发明了压力平衡式叶片泵,为近代液压元件工业或液压传动的逐步建立奠定了基础。
20 世纪初康斯坦丁•尼斯克(G•Constantimsco)对能量波动传递所进行的理论及实际研究;1910年对液力传动(液力联轴节、液力变矩器等)方面的贡献，使这两方面领域得到了发展。
第二次世界大战(1941-1945)期间,在美国机床中有30%应用了液压传动。
应该指出,日本液压传动的发展较欧美等国家晚了近 20 多年。
在 1955 年前后 , 日本迅速发展液压传动,1956 年成立了“液压工业会”。
近20～30 年间，日本液压传动发展之快，居世界领先地位。
液压传动有许多突出的优点，因此它的应用非常广泛，如一般工业用的塑料加工机械、压力机械、机床等；行走机械中的工程机械、建筑机械、农业机械、汽车等；钢铁工业用的冶金机械、提升装置、轧辊调整装置等；土木水利工程用的防洪闸门及堤坝装置、河床升降装置、桥梁操纵机构等；发电厂涡轮机调速装置、核发电厂等等；船舶用的甲板起重机械（绞车）、船头门、舱壁阀、船尾推进器等；特殊技术用的巨型天线控制装置、测量浮标、升降旋转舞台等；军事工业用的火炮操纵装置、船舶减摇装置、飞行器仿真、飞机起落架的收放装置和方向舵控制装置等。
一个完整的液压系统由五个部分组成，即动力元件、执行元件、控制元件、辅助元件和液压油。
液压传动系统常见故障及解决措施分析
液压传动系统常见故障及解决措施分析液压传动系统是一种通过液体传输能量的传动系统，广泛应用于各种工业领域。
由于使用条件、设备老化、材料疲劳等因素，液压传动系统常常会出现故障。
以下是液压传动系统常见故障及解决措施的分析。
1. 油液泄漏：油液泄漏是液压传动系统中最常见的故障之一。
泄漏可能发生在管道连接处、密封件磨损处等地方。
解决措施包括检查并更换松动或磨损的管道连接，更换磨损的密封件，并确保正确安装密封件。
2. 油液污染：油液中的杂质和污染物会引起液压传动系统故障。
解决措施包括定期更换油液，清洁油箱和过滤器，使用高质量的滤芯以及定期检查和清洁液压元件。
3. 液压泵故障：泵是液压系统的核心组件，如果泵出现故障，会导致整个系统失效。
常见的泵故障包括泵内部磨损、密封件老化、进气等。
解决措施包括更换磨损的泵部件，更换老化的密封件，并确保泵的进气口处于正常状态。
4. 液压阀故障：液压阀是控制液压系统流量和方向的关键部件。
常见的阀故障包括卡阀、泄漏等。
解决措施包括清洁阀体和阀芯，更换磨损的阀芯密封件，并确保阀的电磁线圈和电气连接正常。
5. 缸体漏油：液压缸是液压传动系统的执行部件，如果缸体密封不良，会导致漏油现象。
解决措施包括检查并更换密封件，调整缸体连接部位，并确保缸体和活塞杆的表面光滑。
6. 液压管路振动：当液压传动系统运行时，有时会出现管路振动现象，这可能是由于管路设计不合理或液压元件安装不稳定导致的。
解决措施包括重新设计管路布局，增加支撑和减震装置，确保液压元件的牢固安装。
7. 液压泄漏噪音：许多液压系统在运行时会产生噪音，这可能是由于管路泄漏、阀阀芯松动或液压元件磨损导致的。
解决措施包括检查并更换松动的管路连接，修理或更换磨损的阀阀芯，更换磨损的液压元件，并确保液压系统中的油液是清洁的。
对于液压传动系统常见故障的解决措施，必须进行定期的检查和维护，保持设备的正常运行，并且在出现故障时及时采取正确的解决措施，以减少生产中断并延长设备使用寿命。
液压系统故障诊断外文文献翻译
附录1故障诊断液压传动系统由于其独特的优点，即具有广泛的工艺适应性、优良的控制性能和较低廉的成本，在各个领域中获得愈来愈广泛的应用.但由于客观上元、辅件质量不稳定和主观上使用、维护不当，且系统中各元件和工作液体都是在封闭油路内工作,不象机械设备那样直观，也不象电气设备那样可利用各种检测仪器方便地测量各种参数,液压设备中，仅靠有限几个压力表、流量计等来指示系统某些部位的工作参数,其他参数难以测量，而且一般故障根源有许多种可能，这给液压系统故障诊断带来一定困难。
在生产现场，由于受生产计划和技术条件的制约,要求故障诊断人员准确、简便和高效地诊断出液压设备的故障；要求维修人员利用现有的信息和现场的技术条件，尽可能减少拆装工作量,节省维修工时和费用，用最简便的技术手段,在尽可能短的时间内，准确地找出故障部位和发生故障的原因并加以修理，使系统恢复正常运行，并力求今后不再发生同样故障。
液压系统故障诊断的一般原则正确分析故障是排除故障的前提，系统故障大部分并非突然发生,发生前总有预兆，当预兆发展到一定程度即产生故障。
引起故障的原因是多种多样的,并无固定规律可寻。
统计表明，液压系统发生的故障约90%是由于使用管理不善所致为了快速、准确、方便地诊断故障,必须充分认识液压故障的特征和规律,这是故障诊断的基础。
以下原则在故障诊断中值得遵循(1）首先判明液压系统的工作条件和外围环境是否正常需首先搞清是设备机械部分或电器控制部分故障，还是液压系统本身的故障，同时查清液压系统的各种条件是否符合正常运行的要求。
（2）区域判断根据故障现象和特征确定与该故障有关的区域，逐步缩小发生故障的范围，检测此区域内的元件情况,分析发生原因，最终找出故障的具体所在。
(3）掌握故障种类进行综合分析根据故障最终的现象，逐步深入找出多种直接的或间接的可能原因，为避免盲目性，必须根据系统基本原理，进行综合分析、逻辑判断，减少怀疑对象逐步逼近，最终找出故障部位。
汽车变速器的设计外文文献翻译、中英文翻译、外文翻译
汽车变速器的设计外文文献翻译、中英文翻译、外文翻译A manual n。
also known as a standard n。
XXX。
It consistsof gears。
synchros。
roller bearings。
shafts。
and gear selectors。
The main clutch assembly is used to engage and disengage the engine from XXX gears are used to select the desired。
and the sector fork moves gears from one to another using the gearshift knob。
Synchros are used to slow the gear to a。
before it is XXX。
The counter shaft holds the gears in place and against the main input and output shaft。
Unlike automatic ns。
XXX。
as there isno XXX。
Note: XXX "n Shifter" was deleted as it had no XXX.)XXX have four to six forward gears and one reverse gear。
However。
some cars may have up to eight forward gears。
while semi trucks XXX by the number of forward gears。
such as a 5-speed standard n.The n of a standard n includes three shafts: the input shaft。
《机械外文翻译文献翻译液压传动》
英文原文Hydraulic SystemHydraulic presser drive and air pressure drive hydraulic fluid as the transmission is made according to the 17th century, Pascal's principle of hydrostatic pressure to drive the development of an emerging technology, the United Kingdo m in 1795 • Braman Joseph (Joseph Braman ,1749-1814), in London water as a medium to form hydraulic press used in industry, the birth of the world's first hydraulic press. Media work in 1905 will be replaced by oil-water and further improved.Hydraulic transmission There are many outstanding 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 metallurgical 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 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 retractable 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 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) which 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 and 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 relays, 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 control 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, there 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 two 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 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 task, 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 components (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 symbols.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 retracting 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 composition, 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 should 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: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, 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 higher 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 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 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 the 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. Leakage 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 sealing device is an important hydraulic equipment components. The reliability of its机械专业中英文文献翻译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 control 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 diseases1, as a result of heat transmission medium (hydraulic oil) in the flow velocity in various parts of the existence of different, resulting in the existence of a liquid within the internal friction of liquids and pipelines at the sam- e time there is friction between the inner wall, which are a result of hydraulic the reasons for the oil tempera- ture. Temperature will lead to increased internal and external leakage, reducing its mechanical efficiency. At the same time as a result of high temperature, hydraulic oil expansion will occur, resulting in increased com- pression, so that action can not be very good control of transmission. Solution: heat is the inherent characte -ristics of the hydraulic system, not only to minimize eradication. Use a good quality hydraulic oil, hydraulic piping arrangement should be avoided as far as possible the emergence 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 malaise. 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 sophisticated 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 avoiding 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 valve 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 environment. 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 quality 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 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, 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 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 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 power 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 development, 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, high-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 efficiency of the powertrain;(4) development and mechanical, hydraulic, power transmission of the composite portfolio adjustment gear;(5) development of energy saving, energy efficient system function;(6) to further reduce the noise;(7) Application of Hydraulic Cartridge V alves thread technology, compact structure, to reduce the oil spill Water-based hydraulic systemsWater-based hydraulic systems traditionally have been used in hot-metal areas of steel mills. The obvious advantage of water systems in these industries is their fire resistance. Water-based hydraulic systems also have obvious cost advantages over oil-based fluid. First, non-toxic, biodegradable synthetic additives for water cost $5 to $6 per gallon. One gallon of concentrate can make 20 gallons of a 5% solution, so the cost of water-based hydraulic fluid actually can be less than 30 cents per gallon.Considering the costs associated with preventing and cleaning up environmental contamination, water-based hydraulic systems hold the potential for tremendous cost savings at the plant level. Oil that has leaked already becomes a very important problem. It must be collected, properly contained. Water containing synthetic additives, however, can by dumped into plant effluent systems.Cost savings at the plant level don't stop at the lower cost of the fluid and its disposal. Because water-based hydraulic fluid consists of 10 parts water and one part synthetic additive, 5 gallons of additive mixes with water to make 100 gallons of water-based fluid. A 50gallon container is certainly easier to handle than two 55-gallon drums, so warehousing is simpler, cleaner, and less cluttered. Transportation costs also are lower.Other potential plant-wide savings include improved safety for workers because the water-based fluid is non-toxic as well as non-flammable. These attributes can reduce plant insurance rates. Spills cost less to clean up because granular absorbents or absorbent socks are unnecessary. Water is "hot" againThe oil embargo in the 1970s sparked interest in water-based fluids as a less-costly alternative to oils. Even the most expensive water additives became attractive when designers learned that one gallon of concentrate would make 20 gallons of fluid.As oil prices gradually dropped, so did interest in water-based hydraulics. In retrospect, interest in water-based fluids centered around their cost saving potential. Most designers lost interest when they discovered that they could not just change the fluid in their systems from oil to water without making other substantial changes. They then become reluctant to accept other "disadvantages" - read substantial changes - of switching over to water-based hydraulics.What were viewed as disadvantages were really different rules that apply to water-based hydraulic systems? Designers probably resisted learning more about water-based hydraulics because they were intimated by all the work required to lean about how to design a new system or retrofit an older system. By closing their minds to this different technology, they missed the many other advantages of water-based fluid beyond initial cost. Now that environmental concerns have added disposal costs to the price of hydraulic fluids, water-based hydraulics has again become a hot topic.Fighting freezeWater-based hydraulic systems do, of course, have limits to their applications. One limitation is the potential of freezing. This possibility is probably the most significant blockade to more widespread application of机械专业中英文文献翻译water-based systems, especially in the mobile equipment industry. Longwall mining is by far the largest sector of mobile equipment that has been able to take advantage of water-based systems. Temperatures underground do not approach the freezing point of water, and fire resistance is essential. Mobile and even marine equipment used in temperate climates could cash in one the advantages of water based systems, but there is no guarantee that such equipment always will be used in above-freezing temperatures.Nevertheless, adding an anti-freeze to a water-based fluid can depress its freezing temperature to well below 32°F. Ethylene glycol - used in automotive anti-freeze - is toxic and is not biodegradable, so its use for anti-freeze in water-based hydraulic fluid would defeat the environmental advantage water-based fluid has. There is an alternative. Propylene glycol is not toxic and is biodegradable. It costs more than ethylene glycol and is not quite as effective antifreeze, so it must be used in slightly higher concentrations. Two more techniques to reduce freezing potential are to keep fluid circulating continuously and use hose where practical. Sealing the systemTwo more perceived problems with water hydraulic systems are bacterial infestation and difficulty in maintain proper concentrations. Sealing the system from atmosphere can hold bacterial growth in check. Addition of an anti-bacterial agent to the fluid can have a lasting effect on preventing bacterial buildup if air is excluded from the system.A sealed reservoir eliminates another problem suffered by many hydraulic systems: water ingression. This addresses another misconception about water-based systems: water-based systems not sealed from the atmosphere must be closely monitored to ensure that the additive concentration stays within tolerance. That is because water evaporates from the reservoir more readily than the additive does. Consequently, water evaporation causes the additive concentration to increase. When new fluid is added to a system, samples of the existing fluid must be taken to determine the concentration of additive in solution. These results then reveal the ratio of additive to fluid that must be added so that fluid concentration is correct.With a system that seals fluid from the atmosphere, the evaporation problem is virtually eliminated. Fluid that escapes by leakage is a solution containing water and additive. Therefore, the quantity of fluid in the system changes, but concentration does not. System fluid is replen ished simply by adding a pre-mixed solution of water and additive to the reservoir.中文原文液压传动液压传动和气压传动称为流体传动，是根据17世纪帕斯卡提出的液体静压力传动原理而发展起来的一门新兴技术，1795年英国约瑟夫•布拉曼(Joseph Braman,1749-1814)，在伦敦用水作为工作介质，以水压机的形式将其应用于工业上，诞生了世界上第一台水压机。
液压系统的泄漏分析及措施
送审类型：技能人才培养类编号：液压系统的泄漏分析及防治措施许英超（山东铝业职业学院，淄博255000）摘要:泄漏是液压系统的主要故障和维护重点。
本文主要分析了从设计、生产到使用过程中影响液压系统泄漏的主要原因，并提出了相应的以防护为主的解决措施。
关键词:液压系统;泄漏；措施Analysis on Hydraulic System Leakage and Counter measuresYingchao Xu(Shandong Aluminum V ocational College, zibo,255000)Abstract: Leakage is the main problem of Hydraulic system. In this paper, the main factors affecting hydraulic system leakage in the process from design and production to operation are analyzed, the solutions putting prevention first and measures aiming at preventing hydraulic system leakage are put forward.Key Words: hydraulic system; leakage; measure引言：液压系统与其他传动系统相比，具有体积小、重量轻、可实现大范围的无级调速等优点，同时也具有没有严格的传动比、能量损失较大等缺点，而产生这些缺点的主要原因是液压系统的泄漏问题[1]。
泄漏是目前液压系统普遍存在的故障现象。
液压系统一旦发生泄漏,将会引起系统压力建立不起来,影响工作的安全性,同时液压油泄漏还会造成环境污染,增加生产成本,降低生产率,甚至产生无法估计的严重后果。
如何保证液压系统的正常运行,怎样做好泄漏控制措施,是我们需要解决的问题。
液压传动系统常见故障及解决措施分析
液压传动系统常见故障及解决措施分析液压传动系统在工程机械、航空航天、冶金、石油化工等领域得到广泛应用，它具有传动效率高、传动动力大、反应速度快、可靠性高等优点。
液压传动系统也存在着一些常见的故障问题，今天我们就来分析一下液压传动系统常见故障及解决措施。
1. 液压系统泄漏故障液压系统泄漏是液压系统中最为常见的问题之一，如果液压系统存在泄漏，将会导致液压油压力下降，使得系统无法正常工作。
液压系统泄漏的原因可能是液压管路接头处密封不良、密封圈老化磨损、液压油箱内部密封件损坏等。
解决措施：（1）对于液压管路接头处密封不良的情况，可以重新拧紧螺母，或者更换密封垫片。
（2）对于密封圈的老化磨损，需要及时更换密封圈，保证密封效果。
（3）液压油箱内部密封件损坏时，需要清洗油箱，并更换密封件。
2. 液压系统压力过高或过低故障液压系统的工作压力是由泵站输出的压力决定的，如果液压系统的压力过高或者过低都会导致液压系统无法正常工作。
这种故障可能是由于液压泵的失效、阀门堵塞、泄漏等原因引起的。
解决措施：（1）对于液压泵的失效，需要及时更换液压泵。
（2）对于阀门的堵塞，需要清洗或更换阀门。
（3）对于泄漏的情况，需要按照前面提到的方法进行处理。
液压系统在工作过程中如果出现异常振动或噪音，说明液压系统可能存在问题。
液压系统振动或噪音的原因可能是由于液压泵失调、阀门不稳定、油液污染等引起的。
液压传动系统常见故障及解决措施可以通过定期的检查维护来避免和解决。
只有及时发现问题，采取正确的解决措施，才能保证液压传动系统的正常工作，延长设备的使用寿命。
希望大家在使用液压传动系统的能够加强对其维护及检查，确保其安全可靠的工作。
柴油机电控燃油动力系统外文文献翻译、中英文翻译、外文翻译
柴油机电控燃油动力系统外文文献翻译、中英文翻译、外文翻译Design of Diesel Engine Electronic Fuel Control System1.EUP Control MethodThe engine control unit is the most important component ofthe fuel n timing control system。
ensuring the n control requiredto achieve the minimum XXX of the camshaft n。
which is a measurement parameter of the crankshaft。
XXX。
The micro speed regulator (MCU) is controlled by the timer structure module (CTM) and the timing processing unit (TPU)。
When the timer structure module is interrupted by the camshaft trigger。
thecontrol component responds accordingly to the fuel supply system。
and the centralized maintenance module detects a XXX signal tothe timing processing unit (TPU)。
If there are Z teeth。
the span is 360o/z。
The pulse control unit is issued by the PSP and PMM。
The PSP has two working modes: angle-angle and angle-time。
汽车主减速器外文文献翻译、中英文翻译、外文翻译
AUTOMOTIWE FINAL DRIVEFINAL DRIVEA final drive is that part of a power transmission system between the drive shaft and the differential. Its function is to change the direction of the power transmitted by the drive shaft through 90 degrees to the driving axles. At the same time. it provides a fixed reduction between the speed of the drive shaft and the axle driving the wheels.The reduction or gear ratio of the final drive is determined by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear. In passenger vehicles, this speed reduction varies from about 3:1 to 5:1. In trucks it varies from about 5:1 to 11:1. To calculate rear axle ratio, count the number of teeth on each gear. Then divide the number of pinion teeth into the number of ring gear teeth. For example, if the pinion gear has 10 teeth and the ring gear has 30 (30 divided by 10), the rear axle ratio would be 3:1. Manufacturers install a rear axle ratio that provides a compromise between performance and economy. The average passenger car ratio is 3.50:1.The higher axle ratio, 4.11:1 for instance, would increase acceleration and pulling power but would decrease fuel economy. The engine would have to run at a higher rpm to maintain an equal cruising speed.The lower axle ratio. 3:1, would reduce acceleration and pulling power but would increase fuel mileage. The engine would run at a lower rpm while maintaining the same speed.The major components of the final driveinclude the pinion gear, connected to the drive shaft, and a bevel gear or ring gear that is bolted or riveted to the differential carrier. To maintain accurate and proper alignment and tooth contact, the ring gear and differential assembly are mounted in bearings. The bevel drive pinion is supported by two tapered roller bearings, mounted in the differential carrier. This pinion shaft is straddle mounted. meaning that a bearing is located on each side of the pinion shaft teeth. Oil seals prevent the loss of lubricant from the housing where the pinion shaft and axle shafts protrude. As a mechanic, you willencounter the final drive gears in the spiral bevel and hypoid design.Spiral Bevel GearSpiral bevel gears have curved gear teeth with the pinion and ring gear on the same center line. This type of final drive is used extensively in truck and occasionally in older automobiles. This design allows for constant contact between the ring gear and pinion. It also necessitates the use of heavy grade lubricants.Hypoid GearThe hypoid gear final drive is an improvement or variation of the spiral bevel design and is commonly used in light and medium trucks and all domestic rear- wheel drive automobiles. Hypoid gears have replaced spiral bevel gears because they lower the hump in the floor of the vehicle and improve gear-meshing action. As you can see in figure 5-13, the pinion meshes with the ring gear below the center line and is at a slight angle (less than 90 degrees).Figure 5-13.—Types of final drives.This angle and the use of heavier (larger) teeth permit an increased amount of power to be transmitted while the size of the ring gear and housing remain constant. The tooth design is similar to the spiral bevel but includes some of thecharacteristics of the worm gear. This permits the reduced drive angle. The hypoid gear teeth have a more pronounced curve and steeper angle, resulting in larger tooth areas and more teeth to be in contact at the same time. With more than one gear tooth in contact, a hypoid design increases gear life and reduces gear noise. The wiping action of the teeth causes heavy tooth pressure that requires the use of heavy grade lubricants.Double-Reduction Final DriveIn the final drives shown in figure 5-13, there is a single fixed gear reduction. This is the only gear reduction in most automobiles and light- and some medium-duty trucks between the drive shaft and the wheels.Double-reduction final drives are used for heavy- duty trucks. With this arrangement (fig. 5-14) it is not necessary to have a large ring gear to get the necessary gear reduction. The first gear reduction is obtained through a pinion and ring gear as the single fixed gear reduction final drive. Referring to figure 5-14, notice that the secondary pinion is mounted on the primary ring gear shaft. The second gear reduction is the result of the secondary pinion which is rigidly attached to the primary ring gear, driving a large helical gear which is attached to the differential case. Double-reduction final drives may be found on military design vehicles, such as the 5-ton truck. Many commercially designed vehicles of this size use a single- or double-reduction final drive with provisions for two speeds to be incorporatedFigure 5-14.—Double-reduction final driveTwo-Speed Final DriveThe two-speed or dual-ratio final drive is used to supplement the gearing of the other drive train components and is used in vehicles with a single drive axle (fig. 5-15). The operator can select the range or speed of this axle with a button on the shifting lever of the transmission or by a lever through linkageThe two-speed final drive doubles the number of gear ratios available for driving the vehicle under various load and road conditions. For example, a vehicle with a two-speed unit and a five-speed transmission, ten different forward speeds are available. This unit provides a gear ratio high enough to permit pulling a heavy load up steep grades and a low ratio to permit the vehicle to run at high speeds with a light load or no loadThe conventional spiral bevel pinion and ring gear drives the two-speed unit, but aplanetary gear train is placed between the differential drive ring gear and the differential case. The internal gear of the planetary gear train is bolted rigidly to the bevel drive gear. A ring on which the planetary gears are pivoted is bolted to the differential case. A member, consisting of the sun gear and a dog clutch, slides on one of the axle shafts and is controlled through a button or lever accessible to the operatorWhen in high range, the sun gear meshes with the internal teeth on the ring carrying the planetary gears and disengages the dog clutch from the left bearing adjusting ring, which is rigidly held in the differential carrier. In this position, the planetary gear train is locked together. There is no relative motion between the differential case and the gears in the planetary drive train. The differential case is driven directly by the differential ring gear, the same as in the conventional single fixed gear final drive.When shifted into low range, the sun gear is slid out of mesh with the ring carrying the planetary gears. The dog clutch makes a rigid connection with the left bearing adjusting ring. Because the sun gear is integral with the dog clutch, it is also locked to the bearing adjusting rings and remains stationary. The internal gear rotates the planetary gears around the stationary sun gear, and the differential case is driven by the ring on which the planetary gears are pivoted. This action produces the gear reduction, or low speed, of the axleDIFFERENTIAL ACTIONThe rear wheels of a vehicle do not always turn at the same speed. When the vehicle is turning or when tire diameters differ slightly, the rear wheels must rotate at different speeds.If there were a solid connection between each axle and the differential case, the tires would tend to slide, squeal, and wear whenever the operator turned the steering wheel of the vehicle. A differential is designed to prevent this problem.Driving Straight AheadWhen a vehicle is driving straight ahead, the ring gear, the differential case, the differential pinion gears, and the differential side gears turn as a unit. The two differential pinion gears do NOT rotate on the pinion shaft, because they exert equal force on the side gears. As a result, the side gears turn at the same speed as the ring gear, causing both rear wheels to turn at the same speed.Turning CornersWhen the vehicle begins to round a curve, the differential pinion gears rotate on the pinion shaft. This occurs because the pinion gears must walk around the slower turning differential side gear. Therefore, the pinion gears carry additional rotary motion to the faster turning outer wheel on the turn..Differential speed is considered to be 100 percent. The rotating action of the pinion gears carries 90 percent of this speed to the slowing mover inner wheel and sends 110 percent of the speed to the faster rotating outer wheel. This action allows the vehicle to make the turn without sliding or squealing the wheels.Figure 5-15.—Two speed final drive汽车主减速器主减速器主减速器是在传动轴和差速器之间的一个动力传动系统的组成部分。
外文翻译--液压传动系统设计与计算
毕业设计(论文)外文资料翻译系部：机械工程系专业：机械工程及自动化姓名：学号：外文出处：/read-htm-(用外文写)tid-25296.html附件： 1.外文资料翻译译文；2.外文原文。
指导教师评语：此翻译文章较详细地介绍了液压传动系统的设计与计算，阐述了从工况分析入手，确定液压系统主要参数和如何选择液压元件，并对液压系统的性能进行了示范验算，翻译用词基本准确，文笔也较为通顺，具备一定的英语阅读能力。
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附件1：外文资料翻译译文液压传动系统设计与计算1 明确设计要求进行工况分析在设计液压系统时，首先应明确以下问题，并将其作为设计依据。
主机的用途、工艺过程、总体布局以及对液压传动装置的位置和空间尺寸的要求；主机对液压系统的性能要求，如自动化程度、调速范围、运动平稳性、换向定位精度以及对系统的效率、温升等的要求；液压系统的工作环境，如温度、湿度、振动冲击以及是否有腐蚀性和易燃物质存在等情况。
在上述工作的基础上，应对主机进行工况分析，工况分析包括运动分析和动力分析，对复杂的系统还需编制负载和动作循环图，由此了解液压缸或液压马达的负载和速度随时间变化的规律，以下对工况分析的内容作具体介绍。
1.1 运动分析主机的执行元件按工艺要求的运动情况，可以用位移循环图(L—t)，速度循环图(v—t)，或速度与位移循环图表示，由此对运动规律进行分析。
1.1.1 位移循环图L—t图1.1为液压机的液压缸位移循环图，纵坐标L表示活塞位移，横坐标t表示从活塞启动到返回原位的时间，曲线斜率表示活塞移动速度。
图1.1 位移循环图1.1.2 速度循环图v —t(或v —L)工程中液压缸的运动特点可归纳为三种类型。
图1.2为三种类型液压缸的v —t 图，第一种如图1.2中实线所示，液压缸开始作匀加速运动，然后匀速运动，图1.2 速度循环图最后匀减速运动到终点；第二种，液压缸在总行程的前一半作匀加速运动，在另一半作匀减速运动，且加速度的数值相等；第三种，液压缸在总行程的一大半以上以较小的加速度作匀加速运动，然后匀减速至行程终点。
浅析液压系统泄漏故障排除及控制措施
浅析液压系统泄漏故障排除及控制措施摘要:液压系统的泄漏严重影响着机械设备工作的安全性和可靠性，不仅造成油液浪费、环境污染、还会增加机械设备的停工时间，降低作业率、直接增加生产成本，对产品造成污损，因此，我们应及时排除液压系统的泄漏故障并采取行之有效的控制措施来防漏治漏，以安全可靠地使用液压传动系统设备。
本文针对此浅析液压系统泄漏的原因、排除方法以及防漏与治漏的主要措施，对于推广液压传动系统的应用，优化液压系统的设计，指导维修人员排除故障、维护液压设备有着积极意义。
关键词液压系统泄漏故障排除防漏措施液压传动系统具有体积小、重量轻、传递功率大、运行平稳、可实现无级调速等优点，近年来得到广泛应用。
但由于液压油的可压缩性和泄漏造成液压传动不能保证严格的传动比，也因为流体流动的阻力损失和泄漏较大，导致液压系统效率低，由此可见液压系统的泄漏直接制约着液压系统推广应用。
液压系统泄露治理是一项系统性工程，涵盖了液压系统设计，元件的选型，制造，安装，冲洗，调试及运行各个环节。
本文就针对此浅析液压系统泄漏故障的排除及防漏、治漏的措施，对于推广液压传动系统的应用，优化液压系统的设计，指导维修人员排除故障、维护液压设备有着积极意义。
正文液压系统油液的泄漏是指油液在液压元件、附件（含管道）组成的封闭容腔内，由于压差的存在，液压油从高压侧通过缝隙流向低压侧而不做功的过程。
泄漏可分为外泄漏和内泄漏。
外泄漏主要是指液压油从系统漏到环境中，如管路、阀件连接出现松动、密封破损等造成的泄露，致使油液由系统外泄至周围环境。
内泄漏是指因液压元件内高低压力差的存在以及密封件失效，使液压油在系统内部从高压腔流向低压腔，但液压油仍在系统内循环，尽管对环境不造成影响，但内泄严重时可造成液压传动效率低，不能完成指定动作。
一、液压系统常见泄漏故障的排除方法：1.齿轮液压泵内漏的处理方法：1.1液压泵齿轮与泵壳的配合径向间隙超过规定极限偏差。
处理方法是：更换泵壳或采用镶套法修复，保证液压泵齿轮齿顶与壳体配合间隙在正常范围之内（正常间隙为0.13～0.16mm）。
怎样处理液压系统的泄露问题
怎样处理液压系统的泄露问题液压系统的泄漏会造成液压量减少且不能建立正常压力，从而导致系统不能正常工作。
液压系统的泄露主要有两种情况：外漏和内漏。
本文主要介绍液压系统泄漏的两种主要泄漏故障的排除方法以及防漏与治漏的主要措施。
一．液压系统泄漏的两种主要泄漏故障的排除方法A、液压系统内漏故障的排除内漏主要是液压系统内部的液压泵、液压缸、分配器等产生泄漏造成的。
内漏的故障不易被发现，有时还需借助仪器进行检测和调整，才能排除。
归纳起来主要在以下几个方面：1、齿轮液压泵相关部位严重磨损或装配错误（1）液压泵齿轮与泵壳的配合间隙超过规定极限。
处理方法是：更换泵壳或采用镶套法修复，保证液压泵齿轮齿顶与壳体配合间隙在规定范围之内。
（2）齿轮轴套与齿轮端面过度磨损，使卸压密封圈预压缩量不足而失去密封作用，导致液压泵高压腔与低压腔串通，内漏严重。
处理方法是：在后轴套下面加补偿垫片（补偿垫片厚度一般不宜超过2mm），保证密封圈安放的压缩量。
（3）拆装液压泵时，在2个轴套（螺旋油沟的轴套）结合面处，将导向钢丝装错方向。
处理方法是：保证导向钢丝能同时将2个轴套按被动齿轮旋转方向偏转一个角度，使2个轴套平面贴合紧密。
（4）在拆装液压泵时，隔压密封圈老化损坏，卸压片密封胶圈被装错。
处理方法是：若隔压密封圈老化，应更换新件：卸压片密封胶圈应装在吸液腔（口）一侧（低压腔），并保证有一定的预紧压力。
如装在压液腔一侧，密封胶圈会很快损坏，造成高压腔与低压腔相通，使液压泵丧失工作能力。
2、液压缸密封圈老化和损坏活塞杆锁紧螺母松动（1）液压缸活塞上的密封圈、活塞杆与活塞接合处的密封挡圈、定位阀密封圈损坏。
处理方法是：更换密封圈和密封挡圈。
但要注意，选用的密封圈表面应光滑；无皱纹、无裂缝、无气孔、无擦伤等。
（2）活塞杆锁紧螺母松动。
处理方法是：拧紧活塞杆锁紧螺母。
（3）缸筒失圆严重时，可能导致液压缸上下腔的液压油相通。
处理方法：若失圆不太严重，可采取更换加大活塞密封圈的办法来恢复其密封性；若圆度、圆柱度误差超过0.05mm时，则应对缸筒进行珩磨加工，更换加大活塞，来恢复正常配合间隙。
多段液压机械无级变速器的效率外文文献翻译、中英文翻译、外文翻译
多段液压机械无级变速器的效率苑士华 胡纪滨（北京理工大学机械与车辆工程学院）摘要 为了得到液压机械无极变速器的效率。
方法 建立了一个简单液压机械无极传动模型。
结果 在同一段输出时，液压机械无级变速器的效率是连续变化的；并且还高于液压传动的最高效率。
容积效率潜在地影响速度变化，它可以通过适当控制液压单元的容积比率或通过改变段的变化点减小或消除。
当变速器在不同段的情况下工作时，不可变液压单元的机械液压效率导致在同一输出扭矩的情况 下液压油的压力不同；或者在相同的压力下输出不同的扭矩。
结论 多段液压机械无级传动是一种高效率的无极传动。
关键词 液压机械传动；无极传动；传动效率多段液压机械传动是车辆上一种常用的无极传动。
它胜过液压传动和机械传动。
它的效率比较高，速度变化范围比较大。
实验表明两段液压机械无极传动的效率最大可以达到94%，速度范围足够满足车辆上传动。
许多人已经做了很多有用的和先进的工作了，如：Shaker, Ali H, Berger, Guenter, Martin Stenfan,Eli Orshansky (Orshansky Transmission Corp. ) ,William E.Weseloh(Rohr.industries)和吴秀基（北京理工大学教授）。
1、 功率传递路线和效率多段液压机械无极传动的原理如图1所描述。
第1部分和第4部分分别把动力分开和合成。
在第1部分前面和第4部分的后面功率传递只有一条路线。
但是在第1部分和第4部分之间有两条功率传递路线，一条是液压传递路线，另一条是机械传递路线。
通常，液压传递路线，也叫液压传动系统，它由排量可变单元（ 变量泵）和排量不可变单元（定量马达）组成。
机械传递路线，也叫机械传动系统，它由齿轮或行星轮系组成。
在液压传递路线中，通过可变排量单元功率传递可以连续变化。
在机械传递路线中，功率传递时有级的，挡数和段数是相同的。
也就是说，在同一段内，机械传递功率时相等的。
液压专业毕业设计外文翻译(有译文、外文文献)值得收藏哦!
外文原文：The Analysis of Cavitation Problems in the Axial Piston Pumpshu WangEaton Corporation,14615 Lone Oak Road,Eden Prairie, MN 55344This paper discusses and analyzes the control volume of a piston bore constrained by the valve plate in axial piston pumps. The vacuum within the piston bore caused by the rise volume needs to be compensated by the flow; otherwise, the low pressure may cause the cavitations and aerations. In the research, the valve plate geometry can be optimized by some analytical limitations to prevent the piston pressure below the vapor pressure. The limitations provide the design guide of the timings and overlap areas between valve plate ports and barrel kidneys to consider the cavitations and aerations. _DOI: 10.1115/1.4002058_Keywords: cavitation , optimization, valve plate, pressure undershoots1 IntroductionIn hydrostatic machines, cavitations mean that cavities or bubbles form in the hydraulic liquid at the low pressure and collapse at the high pressure region, which causes noise, vibration, and less efficiency.Cavitations are undesirable in the pump since the shock waves formed by collapsed may be strong enough to damage components. The hydraulic fluid will vaporize when its pressure becomes too low or when the temperature is too high. In practice, a number of approaches are mostly used to deal with the problems: (1) raise the liquid level in the tank, (2) pressurize the tank, (3) booster the inlet pressure of the pump, (4) lower the pumping fluid temperature, and (5) design deliberately the pump itself.Many research efforts have been made on cavitation phenomena in hydraulic machine designs. The cavitation is classified into two types in piston pumps: trapping phenomenon related one (which can be preventedby the proper design of the valve plate) and the one observed on the layers after the contraction or enlargement of flow passages (caused by rotating group designs) in Ref. (1). The relationship between the cavitation and the measured cylinder pressure is addressed in this study. Edge and Darling (2) reported an experimental study of the cylinder pressure within an axial piston pump. The inclusion of fluid momentum effects and cavitations within the cylinder bore are predicted at both high speed and high load conditions. Another study in Ref. (3) provides an overview of hydraulic fluid impacting on the inlet condition and cavitation potential. It indicates that physical properties (such as vapor pressure, viscosity, density, and bulk modulus) are vital to properly evaluate the effects on lubrication and cavitation. A homogeneous cavitation model based on the thermodynamic properties of the liquid and steam is used to understand the basic physical phenomena of mass flow reduction and wave motion influences in the hydraulic tools and injection systems (4). Dular et al. (5, 6) developed an expert system for monitoring and control of cavitations in hydraulic machines and investigated the possibility of cavitation erosion by using the computational fluid dynamics (CFD) tools. The erosion effects of cavitations have been measured and validated by a simple single hydrofoil configuration in a cavitation tunnel. It is assumed that the severe erosion is often due to the repeated collapse of the traveling vortex generated by a leading edge cavity in Ref. (7). Then, the cavitation erosion intensity may be scaled by a simple set of flow parameters: the upstream velocity, the Strouhal number, the cavity length, and the pressure. A new cavitation erosion device, called vortex cavitation generator, is introduced to comparatively study various erosion situations (8).More previous research has been concentrated on the valve plate designs, piston, and pump pressure dynamics that can be associated with cavitations in axial piston pumps. The control volume approach and instantaneous flows (leakage) are profoundly studied in Ref. [9]. Berta et al. [10] used the finite volume concept to develop a mathematical model in which the effects of port plate relief grooves have been modeled andthe gaseous cavitation is considered in a simplified manner. An improved model is proposed in Ref. [11] and validated by experimental results. The model may analyze the cylinder pressure and flow ripples influenced by port plate and relief groove design. Manring compared principal advantages of various valve plate slots (i.e., the slots with constant, linearly varying, and quadratic varying areas) in axial piston pumps [12]. Four different numerical models are focused on the characteristics of hydraulic fluid, and cavitations are taken into account in different ways to assist the reduction in flow oscillations [13].The experiences of piston pump developments show that the optimization of the cavitations/aerations shall include the following issues: occurring cavitation and air release, pump acoustics caused by the induced noises, maximal amplitudes of pressure fluctuations, rotational torque progression, etc. However, the aim of this study is to modify the valve plate design to prevent cavitation erosions caused by collapsing steam or air bubbles on the walls of axial pump components. In contrastto literature studies, the research focuses on the development of analytical relationship between the valve plate geometrics and cavitations. The optimization method is applied to analyze the pressure undershoots compared with the saturated vapor pressure within the piston bore.The appropriate design of instantaneous flow areas between the valveplate and barrel kidney can be decided consequently.2 The Axial Piston Pump and Valve PlateThe typical schematic of the design of the axis piston pump is shown in Fig. 1. The shaft offset e is designed in this case to generate stroking containment moments for reducing cost purposes.The variation between the pivot center of the slipper and swash rotating center is shown as a. The swash angle αis the variable that determines the amount of fluid pumped per shaft revolution. In Fig. 1, the n th piston-slipper assembly is located at the angle ofθ. The displacement of the n thnpiston-slipper assembly along the x-axis can be written asx n= R tan（α）sin（θ）+ a sec（α）+ e tan(α) (1)nwhere R is the pitch radius of the rotating group.Then, the instantaneous velocity of the n th piston isx˙n = R 2sec ()αsin （n θ）α+ R tan （α）cos （n θ）ω+ R 2sec ()αsin （α）α + e 2sec ()αα (2)where the shaft rotating speed of the pump is ω=d n θ / dt .The valve plate is the most significant device to constraint flow inpiston pumps. The geometry of intake/discharge ports on the valve plateand its instantaneous relative positions with respect to barrel kidneys areusually referred to the valve plate timing. The ports of the valve plateoverlap with each barrel kidneys to construct a flow area or passage,which confines the fluid dynamics of the pump. In Fig. 2, the timingangles of the discharge and intake ports on the valve plate are listed as(,)T i d δ and (,)B i d δ. The opening angle of the barrel kidney is referred to asϕ. In some designs, there exists a simultaneous overlap between thebarrel kidney and intake/discharge slots at the locations of the top deadcenter (TDC) or bottom dead center (BDC) on the valve plate on whichthe overlap area appears together referred to as “cross -porting” in thepump design engineering. The cross-porting communicates the dischargeand intake ports, which may usually lower the volumetric efficiency. Thetrapped-volume design is compared with the design of the cross-porting,and it can achieve better efficiency 14]. However, the cross-porting isFig. 1 The typical axis piston pumpcommonly used to benefit the noise issue and pump stability in practice.3 The Control Volume of a Piston BoreIn the piston pump, the fluid within one piston is embraced by the piston bore, cylinder barrel, slipper, valve plate, and swash plate shown in Fig. 3. There exist some types of slip flow by virtue of relativeFig. 2 Timing of the valve platemotions and clearances between thos e components. Within the control volume of each piston bore, the instantaneous mass is calculated asM= n V(3)nwhere ρ and n V are the instantaneous density and volumesuch that themass time rate of change can be given asFig. 3 The control volume of the piston boren n n dM dV d V dt dt dtρρ=+ (4) where d n V is the varying of the volume.Based on the conservation equation, the mass rate in the control volume isn n dM q dtρ= (5)where n q is the instantaneous flow rate in and out of one piston. From the definition of the bulk modulus,n dP d dt dtρρβ= (6) where Pn is the instantaneous pressure within the piston bore. Substituting Eqs. (5) and (6) into Eq. (4) yields(?)n n n n n ndP q dV d V w d βθθ=- (7) where the shaft speed of the pump is n d dtθω=. The instantaneous volume of one piston bore can be calculated by using Eq. (1) asn V = 0V + P A [R tan （α）sin （n θ）+ a sec （α） + e tan(α) ] (8)where P A is the piston sectional area and 0V is the volume of eachpiston, which has zero displacement along the x-axis (when n θ=0, π).The volume rate of change can be calculated at the certain swash angle, i.e., α =0, such thattan cos n p n ndV A R d αθθ=（）（） (9) in which it is noted that the piston bore volume increases or decreaseswith respect to the rotating angle of n θ.Substituting Eqs. (8) and (9) into Eq. (7) yields0[tan()cos()] [tan sin sec tan() ]n P n n n p n q A R dP d V A R a e βαθωθαθαα-=-++（）（）（）(10)4 Optimal DesignsTo find the extrema of pressure overshoots and undershoots in the control volume of piston bores, the optimization method can be used in Eq. (10). In a nonlinear function, reaching global maxima and minima is usually the goal of optimization. If the function is continuous on a closed interval, global maxima and minima exist. Furthermore, the global maximum (or minimum) either must be a local maximum (or minimum) in the interior of the domain or must lie on the boundary of the domain. So, the method of finding a global maximum (or minimum) is to detect all the local maxima (or minima) in the interior, evaluate the maxima (or minima) points on the boundary, and select the biggest (or smallest) one. Local maximum or local minimum can be searched by using the first derivative test that the potential extrema of a function f( · ), with derivative ()f ', can solve the equation at the critical points of ()f '=0 [15].The pressure of control volumes in the piston bore may be found as either a minimum or maximum value as dP/ dt=0. Thus, letting the left side of Eq. (10) be equal to zero yieldstan()cos()0n p n q A R ωαθ-= (11)In a piston bore, the quantity of n q offsets the volume varying and thendecreases the overshoots and undershoots of the piston pressure. In this study, the most interesting are undershoots of the pressure, which may fall below the vapor pressure or gas desorption pressure to cause cavitations. The term oftan()cos()p n A R ωαθ in Eq. (11) has the positive value in the range of intake ports (22ππθ-≤≤), shown in Fig. 2, which means that the piston volume arises. Therefore, the piston needs the sufficient flow in; otherwise, the pressure may drop.In the piston, the flow of n q may get through in a few scenariosshown in Fig. 3: (I) the clearance between the valve plate and cylinder barrel, (II) the clearance between the cylinder bore and piston, (III) the clearance between the piston and slipper, (IV) the clearance between the slipper and swash plate, and (V) the overlapping area between the barrel kidney and valve plate ports. As pumps operate stably, the flows in the as laminar flows, which can be calculated as [16]312IV k k Ln i I k h q p L ωμ==∑ (12)where k h is the height of the clearance, k L is the passage length,scenarios I –IV mostly have low Reynolds numbers and can be regarded k ω is the width of the clearance (note that in the scenario II, k ω =2π· r, in which r is the piston radius), and p is the pressure drop defined in the intake ports as p =c p -n p (13)where c p is the case pressure of the pump. The fluid films through theabove clearances were extensively investigated in previous research. The effects of the main related dimensions of pump and the operating conditions on the film are numerically clarified inRefs. [17,18]. The dynamic behavior of slipper pads and the clearance between the slipper and swash plate can be referred to Refs. [19,20]. Manring et al. [21,22] investigated the flow rate and load carrying capacity of the slipper bearing in theoretical and experimental methods under different deformation conditions. A simulation tool calledCASPAR is used to estimate the nonisothermal gap flow between the cylinder barrel and the valve plate by Huang and Ivantysynova [23]. The simulation program also considers the surface deformations to predict gap heights, frictions, etc., between the piston and barrel andbetween the swash plate and slipper. All these clearance geometrics in Eq.(12) are nonlinear and operation based, which is a complicated issue. In this study, the experimental measurements of the gap flows are preferred. If it is not possible, the worst cases of the geometrics or tolerances with empirical adjustments may be used to consider the cavitation issue, i.e., minimum gap flows.For scenario V, the flow is mostly in high velocity and can be described by using the turbulent orifice equation as((Tn d i d d q c A c A θθ= (14)where Pi and Pd are the intake and discharge pressure of the pump and ()i A θ and ()d A θ are the instantaneous overlap area between barrel kidneys and inlet/discharge ports of the valve plate individually.The areas are nonlinear functions of the rotating angle, which is defined by the geometrics of the barrel kidney, valve plate ports,silencing grooves, decompression holes, and so forth. Combining Eqs.(11) –(14), the area can be obtained as3()K IV A θ==(15)where ()A θ is the total overlap area of ()A θ=()()i d A A θλθ+, and λ is defined as=In the piston bore, the pressure varies from low tohigh while passing over the intake and discharge ports of the valve plates. It is possible that the instantaneous pressure achieves extremely low values during the intake area( 22ππθ-≤≤ shown in Fig. 2) that may be located below the vapor pressure vp p , i.e., n vp p p ≤;then cavitations canhappen. To prevent the phenomena, the total overlap area of ()A θ mightbe designed to be satisfied with30()K IV A θ=≥(16)where 0()A θ is the minimum area of 0()A θ=0()()i d A A θλθ+ and 0λis a constant that is0λ=gaseous form. The vapor pressure of any substance increases nonlinearly with temperature according to the Clausius –Clapeyron relation. With the incremental increase in temperature, the vapor pressure becomes sufficient to overcome particle attraction and make the liquid form bubbles inside the substance. For pure components, the vapor pressure can be determined by the temperature using the Antoine equation as /()10A B C T --, where T is the temperature, and A, B, and C are constants[24].As a piston traverse the intake port, the pressure varies dependent on the cosine function in Eq. (10). It is noted that there are some typical positions of the piston with respect to the intake port, the beginning and ending of overlap, i.e., TDC and BDC (/2,/2θππ=- ) and the zero displacement position (θ =0). The two situations will be discussed as follows:(1) When /2,/2θππ=-, it is not always necessary to maintain the overlap area of 0()A θ because slip flows may provide filling up for the vacuum. From Eq. (16), letting 0()A θ=0,the timing angles at the TDC and BDC may be designed as31cos ()tan()122IV c vpk k i I P k p p h A r L ωϕδωαμ--≤+∑ (17) in which the open angle of the barrel kidney is . There is nocross-porting flow with the timing in the intake port.(2) When θ =0, the function of cos θ has the maximum value, which can provide another limitation of the overlap area to prevent the low pressure undershoots suchthat 30(0)K IVA =≥ (18)where 0(0)A is the minimum overlap area of 0(0)(0)i A A =.To prevent the low piston pressure building bubbles, the vaporpressure is considered as the lower limitation for the pressure settings in Eq. (16). The overall of overlap areas then can be derived to have adesign limitation. The limitation is determined by the leakage conditions, vapor pressure, rotating speed, etc. It indicates that the higher the pumping speed, the more severe cavitation may happen, and then the designs need more overlap area to let flow in the piston bore. On the other side, the low vapor pressure of the hydraulic fluid is preferred to reduce the opportunities to reach the cavitation conditions. As a result, only the vapor pressure of the pure fluid is considered in Eqs. (16)–(18). In fact, air release starts in the higher pressure than the pure cavitation process mainly in turbulent shear layers, which occur in scenario V.Therefore, the vapor pressure might be adjusted to design the overlap area by Eq. (16) if there exists substantial trapped and dissolved air in the fluid.The laminar leakages through the clearances aforementioned are a tradeoff in the design. It is demonstrated that the more leakage from the pump case to piston may relieve cavitation problems.However, the more leakage may degrade the pump efficiency in the discharge ports. In some design cases, the maximum timing angles can be determined by Eq. (17)to not have both simultaneous overlapping and highly low pressure at the TDC and BDC.While the piston rotates to have the zero displacement, the minimum overlap area can be determined by Eq. 18 , which may assist the piston not to have the large pressure undershoots during flow intake.6 ConclusionsThe valve plate design is a critical issue in addressing the cavitation or aeration phenomena in the piston pump. This study uses the control volume method to analyze the flow, pressure, and leakages within one piston bore related to the valve plate timings. If the overlap area developed by barrel kidneys and valve plate ports is not properly designed, no sufficient flow replenishes the rise volume by the rotating movement. Therefore, the piston pressure may drop below the saturated vapor pressure of the liquid and air ingress to form the vapor bubbles. To control the damaging cavitations, the optimization approach is used to detect the lowest pressure constricted by valve plate timings. The analytical limitation of the overlap area needs to be satisfied to remain the pressure to not have large undershoots so that the system can be largely enhanced on cavitation/aeration issues.In this study, the dynamics of the piston control volume is developed by using several assumptions such as constant discharge coefficients and laminar leakages. The discharge coefficient is practically nonlinear based on the geometrics, flow number, etc. Leakage clearances of the control volume may not keep the constant height and width as well in practice due to vibrations and dynamical ripples. All these issues are complicated and very empirical and need further consideration in the future. Theresults presented in this paper can be more accurate in estimating the cavitations with these extensive studies.Nomenclature0(),()A A θθ= the total overlap area between valve plate ports and barrel kidneys 2()mmAp = piston section area 2()mmA, B, C= constantsA= offset between the piston-slipper joint and surface of the swash plate 2()mmd C = orifice discharge coefficiente= offset between the swash plate pivot and the shaft centerline of the pump 2()mmk h = the height of the clearance 2()mmk L = the passage length of the clearance 2()mmM= mass of the fluid within a single piston (kg)N= number of pistonsn = piston and slipper counter,p p = fluid pressure and pressure drop (bar)Pc= the case pressure of the pump (bar)Pd= pump discharge pressure (bar)Pi = pump intake pressure (bar)Pn = fluid pressure within the nth piston bore (bar)Pvp = the vapor pressure of the hydraulic fluid(bar)qn, qLn, qTn = the instantaneous flow rate of each piston(l/min)R = piston pitch radius 2()mmr = piston radius (mm)t =time (s)V = volume 3()mmwk = the width of the clearance (mm)x ,x ˙= piston displacement and velocity along the shaft axis (m, m/s) x y z --=Cartesian coordinates with an origin on the shaft centerline x y z '''--= Cartesian coordinates with an origin on swash plate pivot ,αα=swash plate angle and velocity (rad, rad/s)β= fluid bulk modulus (bar)δδ= timing angle of valve plates at the BDC and TDC (rad),B Tϕ= the open angle of the barrel kidney(rad)ρ= fluid density(kg/m3),θω= angular position and velocity of the rotating kit (rad, rad/s)μ=absolute viscosity(Cp),λλ= coefficients related to the pressure drop外文中文翻译：在轴向柱塞泵气蚀问题的分析本论文讨论和分析了一个柱塞孔与配流盘限制在轴向柱塞泵的控制量设计。
变速器外文文献翻译、中英文翻译、外文翻译
TRANSMISSIONEngine output speed is very high, the power and the maximum torque in certain areas of the speed. In order to exert the engine, you must have the best performance, to coordinate the speed of the engine and the actual speeds. Transmission in automobile driving process between the engine and wheels, in different ratios, through the shift in the engine can work under the condition of the best performance. The development trend of the transmission is more complex, more and more is also high automation degree, automatic transmission is the mainstream of the future.Car engines in certain speed can reach the best state, the output power of the bigger, fuel economy and better. Therefore, we hope in the best condition engine always work. But, in the use of the car to have different speed, the contradictions. This contradiction through the transmission to solve.Auto transmission function in a single sentence, is called the speed change, which reduced growth slowing or thickening twist. Why can increase twist, and slowing growth and to reduce twist? Put the power output unchanged, the engine power can be expressed as N = wT, w is turning, T is the angular torque. When N fixed, w and T is inversely proportional to the. So the growth will be reduced, slow increase twist. Auto transmission gear transmission is based on the principle of variable twist, each corresponding to different into gear transmission, in order to adapt to the different operating conditions.General manual transmission shaft set the input and output shaft, and say, another three axis reverse axis. Three main transmission shaft type is the speed of the input shaft structure, the speed of the engine, is also the output shaft speed is presented. By output shaft gear generated between different speeds. The gear is different with different ratio, also have different speed. Such as Zhen Zhou Nissan ZN6481W2G type SUV driver’s dynamic transmission, it is respectively: 1 ratio of 1:3.704 gears, 2.202 2:1, 3:1; 1.414 4 gears, - 5 (1): overdrive dependent.When the car started when the driver choose 1 files, dial 1 1/2 shift fork synchronizer backward joints and 1 shift gear lock on the output shaft, and the power input shaft, and the output shaft shift gears, 1 shift gear drive output shaft, output shaft will power to transmission (red arrows). The typical one shift gear ratio is 3:1, i.e. input shaft turn 3 laps, output shaft turn 1 lap.When the car growth drivers choose 2 files, dial 1 1/2 shift fork synchronizer and 1 separateness from 2 after mating locking output shaft gear and power transmission line, which is similar to the output shaft gear with 2, 1 files output shaft gear. The typical 2 shift gear ratio is 2.2:1, input, output shaft turning 2.2 pivot, 1-1 RPMincreases, torque shift.When gas growth drivers choose 3, dial 1 1/2 shift fork to synchronizer, and back to space three/four file synchronizer will move until 3 gear lock in the output shaft, make the power from the first shaft -- -- on the output shaft transmission gears, 3 through the output shaft gear shifting speed. The typical 3 ratio was 1.7:1, the input shaft turning circle, the output shaft 1.7 turn 1 ring, is further growth.When gas growth drivers choose 4 gears, fork will 3/4 file synchronizer from 3 gear directly with the input shaft driving gear engagement, power transmission directly from the input shaft to the output shaft, and the output shaft is 1:1 ratio and the input shaft speed. Due to the force, and the direct oart shift, the gear transmission efficiency ratio. Cars run most time in order to achieve the best directly file fuel economy.Shift to go into space, transmission in the transmission gears have locked in the output shaft, they cannot drive the output shaft rotation, no power output.General car manual transmission ratio main points above 1-4, usually designers to first identify the lowest (1) and (4) transmission, the ratio between after general distribution according to form. In addition, there is a reverse and overdrive, overdrive called 5 files.When the car to accelerate whether isolated car drivers choose more than 5, 5 gear transmission is typical 0.87:1, namely with big gear drive pinion gear turns, when active 0.87 lap, passive gear has turned over one lap.When the reverse in the opposite direction to the output shaft rotation. If a gear when reverse rotation, plus a gear will become a positive spin. Using this principle, will add a reverse gear do "medium", the direction of rotation axis, so has reversed a reverse axis. Reverse transmission shaft independent in housing, and parallel axis, when oart in gear and gear and oart output shaft gear, output shaft to will instead.Usually the reverse synchronizer is controlled by the jointing, so May 5 files and reverse position is in the same side. Due to the middle, reverse gear transmission is generally greater than 1 gear transmission ratio, twist, some cars met with forward instead of steep open up in reverse.From driving gear transmission is smooth; more is better, more adjacent gear shift between the transmission ratio, shift easy and smooth. But the gear transmission fault is more complex structure, big volume and light auto transmission is now commonly 4-5. At the same time, the transmission ratio is not an integer, but with the decimal point, this is not the whole number of meshing gears, two gear ratio is the euploid number will lead to two gear surface non-uniform wear, tooth surface quality of differences.Manual transmission and synchronizerManual transmission is one of the most common transmissions, referred to as MT. Its basic structure in a single sentence is a central axis, two input shaft, namely, the axial and axial oart, they constituted the transmission of the subject, and, of course, a reverse axis. Manual transmission gear transmission and manual, contain can in axial sliding gears, through different meshing gears to change gear of torsional purpose. The typical structure and principle of the manual transmission.Input shaft also says, it's in front of the spline shaft directly with clutch platen, thus the spline set by the engine relay of torque. The first shaft gear meshing gears, often with oart as input shaft, and the gear on oart will turn. Also called shaft, because even more solid shaft of gear. The output shaft, and the second shaft position have the drive shaft gear, may at any time and under the influence of the control devices and the corresponding oart gear, thus changing the speed and torque itself. The output shaft is associated with tail spline shaft torque transmission shaft, through to drive to gear reducer.Predictably, transmission gear drive forward path is: input shaft gear - oart gnaws gear - because the second shaft gear - corresponding gear. Pour on the axle gear can also control device, by moving axis in the strike, and the output shaft gear and oart gear, in the opposite direction.Most cars have five forward and reverse gear, each one has certain ratio, the majority of gear transmission more than 1, 4 gears transmission is 1, called directly, and ratio is less than 1 of article 5 gear shift accelerated called. The output axis gear in the mesh position, can accept power transmission.Due to the gearbox output shaft to input shaft and the speed of their gear rotating, transform a "synchronization problem". Two rotating speed different meshing gears forcibly inevitable impact and collision damage gear. Therefore, the old transmission shift to use "two feet on-off" method, accelerate in neutral position shift to stay for a while, in the space location on the door, in order to reduce gear speed. But this operation is more complex, difficult to grasp accurately. Therefore designers to create "synchronizer", through the synchronizer will make the meshing gears reach speed and smooth.Currently the synchronous transmission adopts is inertial synchronizer, it mainly consists of joints, synchronizer lock ring etc, it is characteristic of the friction effect on achieving synchronization. Mating, synchronizer and mating locking ring gear tooth circle have chamfering (locking horns), the synchronizer lock ring inside surface of gear engagement ring and the friction surface contact. The lock horns with cone when designing the proper choice, has been made to the surface friction of meshinggears with gear synchronous, also can rapid produces a locking function, prevent the synchronous before meshing gears. When synchronous lock ring of gear engagement with surface contact surface, the outer circle in friction torque under the action of gear speed rapid decrease (increase) or to synchronous speed equal, both locking ring spun concurrent, relative to lock ring gear synchronous speed is zero, thus inertia moment also disappear, then in force, driven by the junction of unimpeded with synchronous lock ring gear engagement, and further to engagement with the engagement ring gear tooth and complete shift process变速器发动机的输出转速非常高，最大功率及最大扭矩在一定的转速区出现。
液压传动系统常见故障及解决措施分析
液压传动系统常见故障及解决措施分析Abstract：The hydraulic transmission system uses hydraulic oil as the working medium for energy conversion and power transmission，because the device itself has compact structure，light weight and small inertia，so it has a wide range of applications. However，in practical application，faults will occur due to the influence of various factors，which will affect the safe and stable operation of the hydraulic transmission system. Therefore，the common faults should be analyzed to provide a strong reference basis for fault prevention and solution. This paper first analyzes the causes and performance characteristics of the common faults of the hydraulic transmission system，and then further expounds the measures to solve the faults of the hydraulic transmission system，which lays a good foundation for improving the safety and stability of the hydraulic transmission system.Keywords：hydraulic transmission system; fault; cause; performance characteristics; measures液压传动系统传送的能量较大，容易操控，换向比较方便，液压元件互换性强，所以可批量生产，这些优点都是液压传动系统应用范围广泛的原因。
液压传动系统泄漏原因及其控制措施探讨
液压传动系统泄漏原因及其控制措施探讨摘要：本文以减少液压传送系统故障以及确保液压传动系统正常运行为出发点，在对液压传动系统泄漏现象产生的原因作出分析的基础上，对液压传动系统泄漏问题的控制措施进行了研究与探讨。
关键词：液压传动系统;泄漏原因;控制措施1.液压传动系统泄漏原因及其控制措施探讨作为液压传统系统中常见的故障之一，液压泄漏产生的原因体现在多个方面，如认为的设计因素、制造因素、安装因素、使用因素、维护因素，以及液压传动系统在运行过程中出现的环境变化因素、老化因素、腐蚀因素以及磨损因素等。
总结而言，液压传动系统中的液压泄漏原因主要可以分为以下几类：一是液压传动系统污染引发液压泄漏。
这种原因所引起的液压泄漏现象要占到液压泄漏故障总量的35%左右，其中包括来的固体颗粒污染、砌体污染、水污染，这些污染的来源来自于液压传统系统外部的侵入、内部的生产以及内部的残留;二是液压传动系统温度过高引发液压泄漏。
一般而言，液压传动系统的温度应当保持在35—60℃，最高的温度应当控制在80℃以下，如果油温出现过高的情况，则可能对液压元件以及液压油产生破坏，从而导致油液产生泄漏;三是液压管路件安装固定与要求不符而产生管路漏油现象。
工程装备所使用的液压管路件包括管接头、液压硬管、液压软管等。
由于这些液压管路长时间在外部暴露，所以因为碰撞与摩擦而产生管道破损并产生管道漏油现象，由于管道漏油具有较大的流量，所以危险度也较高。
2.液压传动系统泄漏现象控制措施2.1对液压油的黏度进行控制黏度是液压传动系统液压油是否合格的重要指标，合理的黏度能够确保液压传动系统在最佳工作状态运行，虽然过高的难度有利于润滑，但是却会产生过大的系统阻力，从而导致压力损失的提高以及功率损失的提高，同时也会导致油温的升高和液压动作不稳定，从而出现噪音。
而当液压油黏度较低时，则会容易产生液压传动系统泄漏问题，并使也要传动系统在不稳定的压力下原型。
液压传动系统中的液压油黏度不仅会受到所选液压油性质的影响，同时会受到有野压力、温度以及所含空气量的影响。
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How to deal with leaking hydraulic system failureAbstract：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 hydraulicThe 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 leakageLeakage 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 analysisGenerally 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.4, Sealing mechanismSo 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 L·Hore 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: ①The working pressure andtemperature 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. ②Speed. 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. ③Cleanliness 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. ④The 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 StrategiesIn 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 downunder 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 ①Control 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. ②Hydraulic 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. ③Select 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. ④Easy 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. ⑤Keep the oil clean.Oil should chang regularly.6 ConclusionLeakage 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.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。