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本科生畢業(yè)設(shè)計(jì) (論文)
外 文 翻 譯
原 文 標(biāo) 題
Hydraulic?System
譯 文 標(biāo) 題
液壓系統(tǒng)?
作者所在系別
機(jī)電工程學(xué)院
作者所在專業(yè)
車(chē)輛工程
作者所在班級(jí)
B13141
作 者 姓 名
許麗杰
作 者 學(xué) 號(hào)
201322288
指導(dǎo)教師姓名
劉志強(qiáng)
指導(dǎo)教師職稱
講師
完 成 時(shí) 間
2017
年
3
月
北華航天工業(yè)學(xué)院教務(wù)處制
譯文標(biāo)題
液壓系統(tǒng)
原文標(biāo)題
Hydraulic?System
作 者
Frank L.Hale
譯 名
弗蘭克.L.赫爾
國(guó) 籍
美國(guó)
原文出處
龍?jiān)雌诳W(wǎng)http://www.qikan.com.cn
譯文：
液壓系統(tǒng)?
一般僅有以下三種基本方法傳遞動(dòng)力：電氣、機(jī)械和液壓。大多數(shù)應(yīng)用系統(tǒng)實(shí)際上是將三種方法組合起來(lái)而得到最有效的最全面的系統(tǒng)。為了合理地確定采取哪種方法，重要的是了解各種方法的顯著特征。例如液壓系統(tǒng)在長(zhǎng)距離上比機(jī)械系統(tǒng)更能經(jīng)濟(jì)地傳遞動(dòng)力。然而液壓系統(tǒng)與電氣系相比，傳遞動(dòng)力的距離較短。?
液壓傳動(dòng)有許多突出的優(yōu)點(diǎn)，它被廣泛的應(yīng)用，如一般工業(yè)用的塑料加工機(jī)械，壓力機(jī)械，機(jī)床等；應(yīng)用機(jī)械設(shè)備工程機(jī)械，建筑機(jī)械，農(nóng)業(yè)機(jī)械，汽車(chē)等；鋼鐵行業(yè)的冶金機(jī)械，起重機(jī)械，還有軋輥調(diào)整裝置等；水利工程中的控制閘門(mén)裝置，河床升降裝置，橋梁和其他操作機(jī)構(gòu)；發(fā)電廠高速渦輪裝置，核電站等；船舶甲板用的起重機(jī)械（絞車(chē)），船頭門(mén)，艙壁閥、船尾推進(jìn)器等；特殊技術(shù)用的巨型天線控制裝置、測(cè)量浮標(biāo)、升降旋轉(zhuǎn)舞臺(tái)等；軍事工業(yè)用的火炮操縱裝置、船舶減搖裝置、飛行器仿真、飛機(jī)起落架的收放裝置和方向舵控制裝置等。特殊技術(shù)的天線控制裝置，測(cè)量浮標(biāo)，升降旋轉(zhuǎn)舞臺(tái)；軍用的火炮操縱裝置，船舶減搖裝置，飛行器仿真，飛機(jī)起落架收放裝置和方向舵控制裝置和其他設(shè)備。?
液壓系統(tǒng)的作用為通過(guò)改變壓強(qiáng)增大作用力。一個(gè)液壓系統(tǒng)的好壞取決于系統(tǒng)設(shè)計(jì)的合理性、系統(tǒng)元件性能的優(yōu)劣，系統(tǒng)的污染防護(hù)和處理，而最后一點(diǎn)尤為重要。近年來(lái)我國(guó)國(guó)內(nèi)液壓技術(shù)有很大的提高，不再單純地使用國(guó)外的液壓技術(shù)進(jìn)行加工。?
一個(gè)完整的液壓系統(tǒng)由五個(gè)部分組成，即動(dòng)力元件、執(zhí)行元件、控制元件、輔助元件（附件）和液壓油。?
動(dòng)力元件的作用是將原動(dòng)機(jī)的機(jī)械能轉(zhuǎn)換成液體的壓力能，指液壓系統(tǒng)中的油泵，它向整個(gè)液壓系統(tǒng)提供動(dòng)力。液壓泵的結(jié)構(gòu)形式一般有齒輪泵、葉片泵和柱塞泵。?
執(zhí)行元件(如液壓缸和液壓馬達(dá))的作用是將液體的壓力能轉(zhuǎn)換為機(jī)械能，驅(qū)動(dòng)負(fù)載作直線往復(fù)運(yùn)動(dòng)或回轉(zhuǎn)運(yùn)動(dòng)。?
控制元件(即各種液壓閥)在液壓系統(tǒng)中控制和調(diào)節(jié)液體的壓力、流量和方向。根據(jù)控制功能的不同，液壓閥可分為壓力控制閥、流量控制閥和方向控制閥。壓力控制閥又分為益流閥(安全閥)、減壓閥、順序閥、壓力繼電器等；流量控制閥包括節(jié)流閥、調(diào)整閥、分流集流閥等；方向控制閥包括單向閥、液控單向閥、梭閥、換向閥等。根據(jù)控制方式不同，液壓閥可分為開(kāi)關(guān)式控制閥、定值控制閥和比例控制閥。?
輔助元件包括油箱、濾油器、油管及管接頭、密封圈、快換接頭、高壓球閥、膠管總成、測(cè)壓接頭、壓力表、油位油溫計(jì)等。
?
液壓油是液壓系統(tǒng)中傳遞能量的工作介質(zhì)，有各種礦物油、乳化液和合成型液壓油等幾大類。?
液壓系統(tǒng)的作用是幫助人類工作，主要通過(guò)執(zhí)行元件將壓力轉(zhuǎn)換為旋轉(zhuǎn)或往復(fù)運(yùn)動(dòng)。?液壓原理：它由兩個(gè)不同大小的缸體充滿了水或油。充滿水的稱為“水壓機(jī)”，充滿油的稱為“液壓機(jī)”。兩個(gè)液缸每個(gè)都有一個(gè)可動(dòng)的活塞，如果在小活塞上加點(diǎn)壓力，根據(jù)帕斯卡定律，小活塞的壓力通過(guò)液體的壓力傳遞到大活塞，頂端的活塞將前進(jìn)很長(zhǎng)的距離?；拘』钊臋M截面積為S1，外加一個(gè)小活塞上一個(gè)向下的力F1。因此，小活塞對(duì)液體的壓強(qiáng)P=F1/S1的，可以在所有方向上傳輸同樣大小。通過(guò)大活塞的壓力也為P。如果大活塞的橫截面積為S2，活塞的壓強(qiáng)P向上的壓力F2=P*S2，橫截面積是小活塞的幾倍，加給小活塞小的力，活塞會(huì)有大的壓力，由此用液壓機(jī)壓制膠合板，油，提起重物，鍛造煉鋼。?
液壓系統(tǒng)成功而又廣泛使用的秘密在于它的通用性和易操作性。液壓動(dòng)力傳遞不會(huì)像機(jī)械系統(tǒng)那樣受到機(jī)器幾何形體的制約，另外，液壓系統(tǒng)不會(huì)像電氣系統(tǒng)那樣受到材料物理性能的制約，它對(duì)傳遞功率幾乎沒(méi)有量的限制。例如，一個(gè)電磁體的性能受到鋼的磁飽和極限的限制，相反，液壓系統(tǒng)的功率僅僅受材料強(qiáng)度的限制。?
企業(yè)為了提高生產(chǎn)率將越來(lái)越依靠自動(dòng)化，這包括遠(yuǎn)程和直接控制生產(chǎn)操作加工過(guò)程和材料處理等。液壓動(dòng)力之所以成為自動(dòng)化的重要組成部分，是因?yàn)樗腥缦轮饕乃姆N優(yōu)點(diǎn)：?
1?控制方便，精確通過(guò)操作一個(gè)簡(jiǎn)單的操縱桿和按鈕，液壓系統(tǒng)的操作者便能立即起動(dòng)、停止、加減速和能提供任意功率、位置精度為萬(wàn)分之一英寸的位置控制力。一個(gè)使飛機(jī)駕駛員升起和落下起落架的液壓系統(tǒng)，當(dāng)飛行員向某方向移動(dòng)控制閥，壓力油流入液壓缸的某一腔從而降下起落架。飛行員向相反方向移動(dòng)控制閥，允許油液進(jìn)入液壓缸的另一腔來(lái)收起落架。?
2?增力，一個(gè)液壓系統(tǒng)沒(méi)有使用笨重的齒輪、滑輪杠桿就能簡(jiǎn)單有效地將不到一盎司的力放大產(chǎn)生兒上百噸力的輸出。?
3?恒力或恒扭矩，只有液壓系統(tǒng)能提供不隨速度變化而變化的恒力或恒扭矩，它可以驅(qū)動(dòng)對(duì)象從每小時(shí)移動(dòng)幾英寸到每分鐘幾百英寸．從每小時(shí)幾轉(zhuǎn)到每分鐘幾千轉(zhuǎn)。?
4?簡(jiǎn)便、安全、經(jīng)濟(jì)，總的來(lái)說(shuō)，液壓系統(tǒng)比機(jī)械或電氣系統(tǒng)使用更少的運(yùn)動(dòng)部件，因此，它們運(yùn)行與維護(hù)簡(jiǎn)便。這使得系統(tǒng)結(jié)構(gòu)緊湊，安全可靠。例如一種用于車(chē)輛上的新型動(dòng)力轉(zhuǎn)向控制裝置己淘汰其他類型的轉(zhuǎn)向動(dòng)力裝置，該轉(zhuǎn)向部件中包含有人力操縱
方向控制閥和分配器。因?yàn)檗D(zhuǎn)向部件是全液壓的，沒(méi)有萬(wàn)向節(jié)、軸承、減速齒輪等機(jī)械連接，這使得系統(tǒng)簡(jiǎn)單緊湊。另外，只需輸入很小的扭矩就能產(chǎn)生滿足極惡劣工作條件所需的控制力．這對(duì)操作空間限制而需要小方向盤(pán)的場(chǎng)合很重要，這也是減輕操作者疲勞所必需的。?
液壓系統(tǒng)的其他優(yōu)點(diǎn)包括雙向運(yùn)動(dòng)、過(guò)載保護(hù)和無(wú)級(jí)變速控制，在已有的任何動(dòng)力系統(tǒng)中液壓系統(tǒng)亦具有最大的單位質(zhì)量功率比。?
液壓系統(tǒng)也有三個(gè)弱點(diǎn)：?
1?由于傳動(dòng)介質(zhì)（液壓油）流動(dòng)的過(guò)程中部分位置流速不同，導(dǎo)致液體內(nèi)部出現(xiàn)摩擦，同時(shí)液體與管道內(nèi)壁也有摩擦，這都是液壓油溫度升高的原因。溫度過(guò)高會(huì)導(dǎo)致更多的內(nèi)部和外部的泄漏，減少其機(jī)械效率。同時(shí)由于較高的溫度，液壓油會(huì)膨脹。導(dǎo)致可壓縮增大，使操作不能很好的控制傳輸。解決方法：高溫是液壓系統(tǒng)的自身問(wèn)題，只能最大減輕不能根除。使用質(zhì)量更好的液壓油，液壓管的布局盡量避免出現(xiàn)彎曲，使用高品質(zhì)的管材和管件，液壓閥等。?
2?液壓系統(tǒng)的震動(dòng)也是弱點(diǎn)之一。由于液壓油在管道中流動(dòng)的高速?zèng)_擊和控制閥的打開(kāi)關(guān)閉的過(guò)程中的影響是系統(tǒng)振動(dòng)的原因。強(qiáng)烈震動(dòng)會(huì)導(dǎo)致系統(tǒng)的控制動(dòng)作錯(cuò)誤，也會(huì)使系統(tǒng)中一些更復(fù)雜精密設(shè)備出現(xiàn)錯(cuò)誤，從而導(dǎo)致系統(tǒng)故障。解決方案：液壓管應(yīng)該是固定的，以避免急彎。為了避免頻繁流動(dòng)方向的變化，無(wú)法避免時(shí)應(yīng)將減震措施應(yīng)該做到最好。整個(gè)液壓系統(tǒng)應(yīng)具有良好的減振措施，同時(shí)避免在系統(tǒng)外部振蕩器的影響。?
3?液壓系統(tǒng)有內(nèi)泄露和外泄露，內(nèi)泄漏是指發(fā)生在系統(tǒng)中的泄露過(guò)程，如液壓活塞?-?缸的泄漏，控制閥滑閥與閥體之間的泄漏，如兩側(cè)。內(nèi)泄漏雖然沒(méi)有液壓油的損失，但是由于泄露，已經(jīng)確定的控制動(dòng)作會(huì)受到影響，直至系統(tǒng)故障。外泄露是指發(fā)生在系統(tǒng)與外部環(huán)境之間的泄露。液壓油直接泄露到環(huán)境中，除了會(huì)影響工作環(huán)境，沒(méi)有足夠的動(dòng)力將導(dǎo)致系統(tǒng)故障。液壓油泄露到環(huán)境中也有火災(zāi)的危險(xiǎn)。解決方案：使用質(zhì)量更好的密封件，以提高設(shè)備的加工精度。?
在液壓系統(tǒng)及其系統(tǒng)中，密封裝置用來(lái)防止工作介質(zhì)的泄漏及外界灰塵和異物的侵入。其中起密封作用的元件，即密封件。外漏會(huì)造成工作介質(zhì)的浪費(fèi)，污染機(jī)器和環(huán)境，甚至引起機(jī)械操作失靈及設(shè)備人身事故。內(nèi)漏會(huì)引起液壓系統(tǒng)容積效率急劇下降，達(dá)不到所需要的工作壓力，甚至不能進(jìn)行工作。侵入系統(tǒng)中的微小灰塵顆粒，會(huì)引起或加劇液壓元件摩擦副的磨損，進(jìn)一步導(dǎo)致泄漏。?
因此，密封件和密封裝置是液壓設(shè)備的一個(gè)重要組成部分。它的工作的可靠性和使用壽命，是衡量液壓系統(tǒng)好壞的一個(gè)重要指標(biāo)。除間隙密封外，都是利用密封件，使相鄰兩個(gè)偶合表面間的間隙控制在需要密封的液體能通過(guò)的最小間隙以下。在接觸式密封中，分為自封式壓緊型密封和自封式自緊型密封（即唇形密封）兩種。
原文：
Hydraulic?System?
There?are?only?three?basic?methods?of?transmitting?power：Electrical，mechanical．a(chǎn)nd?fluid?power．Most?applications?actually?use?a?combination?of?the?three?methods?to?obtain?the?most?efficient?overall?system．To?properly?determine?which?principle?method?to?use。it?is?important?to?know?the?salient?features?of?each?type．For?example，fluid?systems?call?transmit?power?more?economically?Over?greater?distances?than?Can?mechanical?types．However。fluid?systems?are?restricted?to?shorter?distances?than?are?electrical?systems．??
Hydraulic?transmission?there?are?many?outstanding?advantages,?it?is?widely?used,?such?as?general?industrial?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?industry?metallurgical?machinery,?lifting?equipment,?such?as?roller?adjustment?device;?civil?water?projects?with?flood?control?and?dam?gate?devices,?bed?lifts?installations,?bridges?and?other?manipulation?of?institutions;?speed?turbine?power?plant?installations,?nuclear?power?plants,?etc.;?ship?from?the?deck?heavy?machinery?(winch),?the?bow?doors,?bulkhead?valve,?stern?thruster,?etc.;?special?antenna?technology?giant?with?control?devices,?measurement?buoys,?movements?such?as?rotating?stage;?military-industrial?control?devices?used?in?artillery,?ship?anti-?rolling?devices,?aircraft?simulation,?aircraft?retractable?landing?gear?and?rudder?control?devices?and?other?devices.?
The?role?of?the?hydraulic?system?to?increase?the?force?by?changing?the?pressure.?A?hydraulic?system?is?good?or?bad?depends?on?the?system?design?is?reasonable,?the?merits?of?the?performance?system?components,?system,?pollution?prevention?and?treatment,?while?the?last?point?is?particularly?important.?In?recent?years,?China's?domestic?hydraulic?technology?has?greatly?improved,?not?simply?using?hydraulic?technology?from?abroad?for?processing.?
?A?complete?hydraulic?system?consists?of?five?parts,?namely,?power?components,?the?implementation?of?components,?control?components,?auxiliary?components?(Annex)?and?the?hydraulic?oil.??
The?role?of?dynamic?components?is?the?original?motivation?of?the?mechanical?energy?into?fluid?pressure?energy,?the?hydraulic?system?of?pumps,?which?provide?power?to?the?entire?hydraulic?system.?Structures?of?hydraulic?pumps?generally?have?gear?pumps,?vane?pumps?and?piston?pumps.
Implementation?of?components?(such?as?hydraulic?cylinders?and?hydraulic?motors)?is?to?pressure?the?liquid?can?be?converted?to?mechanical?energy?to?drive?the?load?for?a?linear?reciprocating?movement?or?rotational?movement.?
Control?components?in?the?hydraulic?system?control?and?regulation?of?fluid?pressure,?flow?and?direction.?According?to?the?different?control?functions,?hydraulic?valves?can?be?divided?into?pressure?control?valves,?flow?control?valves?and?directional?control?valve.?Pressure?control?valve?is?divided?into?benefits?flow?valve?(safety?valve),?pressure?relief?valve,?sequence?valve,?pressure?switch,?etc.;?flow?control?valves?including?throttle,?adjusting?valves,?flow?diversion?valve?assembly;?Directional?control?valve?includes?a?check?valve,?check?valve,?shuttle?valve,?valve?and?so?on.?Under?the?control?of?different?ways,?hydraulic?valves?can?be?divided?into?switching?control?valves,?control?valves?and?the?fixed?value?proportional?control?valve.??
Auxiliary?components,?including?fuel?tanks,?filters,?tubing?and?pipe?joints,?seals,?quick?couplings,?high?pressure?ball?valve,?hose?assembly,?pressure?fittings,?pressure?gauge,?oil?level,?oil?temperature?meter?and?so?on.??
Hydraulic?system?of?hydraulic?oil?is?the?work?of?the?energy?transfer?medium,?a?variety?of?mineral?oil,?emulsion,?oil?hydraulic?molding?Hop?categories?
The?role?of?the?hydraulic?system?is?to?help?humanity?work.?Mainly?by?the?implementation?of?components?to?rotate?or?pressure?into?a?reciprocating?motion.??
Hydraulic?principle?：It?consists?of?two?cylinders?of?different?sizes?and?composition?of?fluid?in?the?fluid?full?of?water?or?oil.?Water?is?called?"hydraulic?press";?the?said?oil?filled?"hydraulic?machine."?Each?of?the?two?liquid?a?sliding?piston,?if?the?increase?in?the?small?piston?on?the?pressure?of?a?certain?value,?according?to?Pascal's?law,?small?piston?to?the?pressure?of?the?pressure?through?the?liquid?passed?to?the?large?piston,?piston?top?will?go?a?long?way?to?go.?Based?cross-sectional?area?of?the?small?piston?is?S1,?plus?a?small?piston?in?the?downward?pressure?on?the?F1.?Thus,?a?small?piston?on?the?liquid?pressure?to?P?=?F1/SI,?Can?be?the?same?size?in?all?directions?to?the?transmission?of?liquid.?"By?the?large?piston?is?also?equivalent?to?the?inevitable?pressure?P.?If?the?large?piston?is?the?cross-sectional?area?S2,?the?pressure?P?on?the?piston?in?the?upward?pressure?generated?F2?=?PxS2?Cross-sectional?area?is?a?small?multiple?of?the?piston?cross-sectional?area.?From?the?type?known?to?add?in?a?small?piston?of?a?smaller?force,
the?piston?will?be?in?great?force,?for?which?the?hydraulic?machine?used?to?suppress?plywood,?oil,?extract?heavy?objects,?such?as?forging?steel.?
The?secret?of?hydraulic?systems?success?and?widespread?use?is?its?versatility?and?manageability．Fluid?power?is?not?hindered?by?the?geometry?operations?when?the?potential?difference?between?the?tool?and?the?work?piece?is?sufficiently?high,?a?transient?spark?discharges?through?the?fluid,?removing?a?very?small?amount?of?metal?from?the?work?piece?of?the?machine?as?is?the?ease?in?mechanical?systems．Alsopower?can?be?transmitted?in?almost?limitless?quantities?because?fluid?systems?are?not?so?limited?by?the?physical?1imitations?of?materials?as?are?the?electrical?systems．For?examplethe?performance?of?an?electromagnet?is?limited?by?The?saturation?limit?of?steel．On?the?otherhandthe?power?limit?of?fluid?systems?is?1imited?only?by?the?strength?capacity?of?the?material．?
Industry?is?going?to?depend?more?and?more?on?automation?in?order?to?increase?productivity.Thisincludes?remote?and?direct?control?of?production?operationsmanufacturing?processes。and?materials?handling．Fluid?power?is?the?muscle?of?automation?because?of?advantages?in?the?following?four?major?categories．?
1?The?precise?convenient?control?by?operating?a?simple?joystick?and?buttons,?the?operators?of?the?hydraulic?system?and?can?immediately?start,?stop,?and?deceleration?and?can?provide?any?power,?position?precision?for?one?over?ten?thousand?inch?position?control.?A?make?the?pilot?rises?and?fall?the?landing?gear?on?the?hydraulic?system,?when?the?pilot?to?a?certain?direction?control?valves,?pressure?oil?into?hydraulic?cylinder?of?a?cavity?and?came?down?on?the?landing?gear.?The?pilot?to?move?in?the?opposite?direction?control?valves,?allow?the?oil?into?the?hydraulic?cylinder?of?another?chamber?to?take?back?on?the?landing?gear.??
2?Multiplication?of?force．?A?fluid?power?system(without?using?cumbersome?gears，pulleys，and?levers)Can?multiply?forces?Simply?and?efficiently?from?a?fraction?of?an?ounce?to?several?hundred?tons?of?output．?
3?Constant?force?or?torque．Only?fluid?power?systems?are?capable?of?providing?constant?force?or?torque?regardless?of?speed?changes．This?is?accomplished?whether?the?work?output?moves?a?few?inches?per?hourseveral?hundred?inches?per?minutea?few?revolutions?per?hour．or?thousands?of?revolutions?per?minute．?4?Simplicity，safety，economy．general，fluid?power?systems?use?fewer?moving?parts?thant?of?high?temperature,?hydraulic?oil?expansion?will?occur,?resulting?in?increased?compression,?so?that?action?can?not?be?very?good?control?of?transmission.?Solution:?heat?is?the?inherent?characteristics?of?the?hydraulic?system,?not?only?to?minimize?eradication.?Use?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?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?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?hydraulic?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?environments.?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?environment?of?the?hydraulic?oil?was?also?the?danger?of?fire.?Solution:?the?use?of?better?quality?seals?to?improve?the?machining?accuracy?of?equipment.?
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?component.?The?reliability?of?its?work?and?life?is?a?measure?of?the?hydraulic?system?an?important?indicator?of?good?or?bad.?In?addition?to?the?closed?space,?are?the?use?of?seals,?so?that?two?adjacent?coupling?surface?of?the?gap?between?the?need?to?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?(is,?sealed?lips)?two.?
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