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本科生畢業(yè)設(shè)計 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 機電工程學(xué)院 作者所在專業(yè) 車輛工程 作者所在班級 B13141 作 者 姓 名 許麗杰 作 者 學(xué) 號 201322288 指導(dǎo)教師姓名 劉志強 指導(dǎo)教師職稱 講師 完 成 時 間 2017 年 3 月 北華航天工業(yè)學(xué)院教務(wù)處制 0 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 籍 美國 原文出處 龍源期刊網(wǎng) 譯文 液壓系統(tǒng) 一般僅有以下三種基本方法傳遞動力 電氣 機械和液壓 大多數(shù)應(yīng)用系統(tǒng) 實際上是將三種方法組合起來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)在長距離上比機 械系統(tǒng)更能經(jīng)濟(jì)地傳遞動力 然而液壓系統(tǒng)與電氣系相比 傳遞動力的距離較短 液壓傳動有許多突出的優(yōu)點 它被廣泛的應(yīng)用 如一般工業(yè)用的塑料加工機 械 壓力機械 機床等 應(yīng)用機械設(shè)備工程機械 建筑機械 農(nóng)業(yè)機械 汽車等 鋼鐵行業(yè)的冶金機械 起重機械 還有軋輥調(diào)整裝置等 水利工程中的控制閘門 裝置 河床升降裝置 橋梁和其他操作機構(gòu) 發(fā)電廠高速渦輪裝置 核電站等 船舶甲板用的起重機械 絞車 船頭門 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 測量浮標(biāo) 升降旋轉(zhuǎn)舞臺等 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 測量浮標(biāo) 升降旋轉(zhuǎn)舞臺 軍用的火炮操縱裝置 船舶減 搖裝置 飛行器仿真 飛機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)的作用為通過改變壓強增大作用力 一個液壓系統(tǒng)的好壞取決于系 統(tǒng)設(shè)計的合理性 系統(tǒng)元件性能的優(yōu)劣 系統(tǒng)的污染防護(hù)和處理 而最后一點尤 為重要 近年來我國國內(nèi)液壓技術(shù)有很大的提高 不再單純地使用國外的液壓技 術(shù)進(jìn)行加工 一個完整的液壓系統(tǒng)由五個部分組成 即動力元件 執(zhí)行元件 控制元件 輔助元件 附件 和液壓油 動力元件的作用是將原動機的機械能轉(zhuǎn)換成液體的壓力能 指液壓系統(tǒng)中的 油泵 它向整個液壓系統(tǒng)提供動力 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)換為機械能 驅(qū) 動負(fù)載作直線往復(fù)運動或回轉(zhuǎn)運動 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 1 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 測壓接頭 壓力表 油位油溫計等 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 主要通過執(zhí)行元件將壓力轉(zhuǎn)換為旋轉(zhuǎn)或往 復(fù)運動 液壓原理 它由兩個不同大小的缸體充滿了水或油 充滿水的稱為 水 壓機 充滿油的稱為 液壓機 兩個液缸每個都有一個可動的活塞 如果在 小活塞上加點壓力 根據(jù)帕斯卡定律 小活塞的壓力通過液體的壓力傳遞到大活 塞 頂端的活塞將前進(jìn)很長的距離 基本小活塞的橫截面積為 S1 外加一個小活 塞上一個向下的力 F1 因此 小活塞對液體的壓強 P F1 S1 的 可以在所有方向 上傳輸同樣大小 通過大活塞的壓力也為 P 如果大活塞的橫截面積為 S2 活塞 的壓強 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 活塞會有大的壓力 由此用液壓機壓制膠合板 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 液壓動力傳 遞不會像機械系統(tǒng)那樣受到機器幾何形體的制約 另外 液壓系統(tǒng)不會像電氣系 統(tǒng)那樣受到材料物理性能的制約 它對傳遞功率幾乎沒有量的限制 例如 一個 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 度的限制 企業(yè)為了提高生產(chǎn)率將越來越依靠自動化 這包括遠(yuǎn)程和直接控制生產(chǎn)操作 加工過程和材料處理等 液壓動力之所以成為自動化的重要組成部分 是因為它 有如下主要的四種優(yōu)點 1 控制方便 精確通過操作一個簡單的操縱桿和按鈕 液壓系統(tǒng)的操作者便 能立即起動 停止 加減速和能提供任意功率 位置精度為萬分之一英寸的位置 控制力 一個使飛機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 控制閥 允許油液進(jìn)入液壓缸的另一腔來收起落架 2 增力 一個液壓系統(tǒng)沒有使用笨重的齒輪 滑輪杠桿就能簡單有效地將不 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)動對象從每小時移動幾英寸到每分鐘幾百英寸 從每小時幾轉(zhuǎn)到每分鐘 幾千轉(zhuǎn) 4 簡便 安全 經(jīng)濟(jì) 總的來說 液壓系統(tǒng)比機械或電氣系統(tǒng)使用更少的運 2 動部件 因此 它們運行與維護(hù)簡便 這使得系統(tǒng)結(jié)構(gòu)緊湊 安全可靠 例如一 種用于車輛上的新型動力轉(zhuǎn)向控制裝置己淘汰其他類型的轉(zhuǎn)向動力裝置 該轉(zhuǎn)向 部件中包含有人力操縱 方向控制閥和分配器 因為轉(zhuǎn)向部件是全液壓的 沒有萬向節(jié) 軸承 減速 齒輪等機械連接 這使得系統(tǒng)簡單緊湊 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 這對操作空間限制而需要小方向盤的場合很重 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)點包括雙向運動 過載保護(hù)和無級變速控制 在已有的任 何動力系統(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)也有三個弱點 1 由于傳動介質(zhì) 液壓油 流動的過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 過高會導(dǎo)致更多的內(nèi)部和外部的泄漏 減少其機械效率 同時由于較高的溫度 液壓油會膨脹 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)的震動也是弱點之一 由于液壓油在管道中流動的高速沖擊和控 制閥的打開關(guān)閉的過程中的影響是系統(tǒng)振動的原因 強烈震動會導(dǎo)致系統(tǒng)的控制 動作錯誤 也會使系統(tǒng)中一些更復(fù)雜精密設(shè)備出現(xiàn)錯誤 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 為了避免頻繁流動方向的變化 無 法避免時應(yīng)將減震措施應(yīng)該做到最好 整個液壓系統(tǒng)應(yīng)具有良好的減振措施 同 時避免在系統(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)泄漏雖然沒有液 壓油的損失 但是由于泄露 已經(jīng)確定的控制動作會受到影響 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 會影響工作環(huán)境 沒有足夠的動力將導(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 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 外漏會造成工作介質(zhì)的浪費 污 染機器和環(huán)境 甚至引起機械操作失靈及設(shè)備人身事故 內(nèi)漏會引起液壓系統(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)好壞的一個重要指標(biāo) 除間隙密封外 都是利用 密封件 使相鄰兩個偶合表面間的間隙控制在需要密封的液體能通過的最小間隙 3 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 4 原文 Hydrau lic System There a re only three basic metho ds of transm itting power Electrical mechanic al and flui d power Most applic ations actual ly use a com bination of t he three met hods to obta in the most efficient ove rall system To proper ly determine which princ iple method to use it is important to know the sa lient feature s of each typ e For exa mple fluid systems cal l transmit po wer more ec onomically 5 Over greater distances th an Can mec hanical type s However fluid syst ems are rest ricted to sho rter distance s than are el ectrical syst ems Hydrau lic transmiss ion there are many outst anding adva ntages it is widely used such as gen eral industri al use of pla stics process ing machine ry the press ure of machi nery machi ne tools etc operating machinery e ngineering machinery construction machinery agricultural machinery 6 automobiles etc iron a nd steel ind ustry metall urgical mac hinery liftin g equipment such as roll er adjustme nt device ci vil water pr ojects with f lood control and dam ga te devices b ed lifts insta llations brid ges and othe r manipulati on of institu tions speed turbine pow er plant inst allations nu clear power plants etc ship from th e deck heav y machinery winch the bow doors bulkhead va lve stern thr uster etc s pecial anten na technolo 7 gy giant wit h control de vices meas urement buo ys moveme nts such as r otating stage military industrial co ntrol device s used in arti llery ship a nti rolling devi ces aircraft simulation aircraft retra ctable landi ng gear and rudder contr ol devices a nd other dev ices The rol e of the hydr aulic system to increase t he force by changing th e pressure A hydraulic system is go od or bad de pends on the system desi gn is reason 8 able the me rits of the pe rformance s ystem comp onents syst em pollutio n prevention and treatme nt while the last point is particularly important I n recent yea rs China s d omestic hyd raulic techn ology has gr eatly improv ed not simp ly using hyd raulic techn ology from abroad for p rocessing A com plete hydrau lic system c onsists of fi ve parts na mely power components the implem entation of c omponents control com ponents aux 9 iliary compo nents Anne x and the h ydraulic oil The rol e of dynami c componen ts is the orig inal motivati on of the me chanical ene rgy into flui d pressure e nergy the h ydraulic syst em of pump s which pro vide power t o the entire hydraulic sy stem Struct ures of hydr aulic pumps generally h ave gear pu mps vane p umps and pi ston pumps Imple mentation of components such as hy draulic cylin ders and hy draulic moto 10 rs is to pres sure the liqu id can be co nverted to m echanical en ergy to driv e the load fo r a linear rec iprocating m ovement or rotational m ovement Control components in the hydra ulic system control and regulation o f fluid press ure flow an d direction According t o the differe nt control fu nctions hyd raulic valves can be divi ded into pre ssure contro l valves flo w control va lves and dir ectional con trol valve P ressure cont rol valve is 11 divided into benefits flo w valve saf ety valve p ressure relie f valve sequ ence valve pressure swi tch etc flo w control va lves includi ng throttle a djusting val ves flow di version valv e assembly Directional control valv e includes a check valve check valve shuttle val ve valve an d so on Un der the contr ol of differe nt ways hyd raulic valves can be divi ded into swi tching contr ol valves co ntrol valves and the fixe d value prop ortional cont 12 rol valve Auxilia ry compone nts includin g fuel tanks filters tubi ng and pipe joints seals quick coupl ings high pr essure ball v alve hose as sembly pres sure fittings pressure ga uge oil leve l oil temper ature meter and so on Hydrau lic system o f hydraulic oil is the wo rk of the ene rgy transfer medium a v ariety of mi neral oil em ulsion oil h ydraulic mol ding Hop ca tegories The rol e of the hydr aulic system is to help h 13 umanity wor k Mainly b y the imple mentation of components to rotate or pressure int o a reciproc ating motion Hydraulic pr inciple It consists of t wo cylinder s of differen t sizes and c omposition of fluid in th e fluid full o f water or oi l Water is c alled hydra ulic press t he said oil fi lled hydrau lic machine Each of th e two liquid a sliding pis ton if the in crease in the small pisto n on the pre ssure of a ce rtain value according to 14 Pascal s law small pisto n to the pres sure of the p ressure thro ugh the liqui d passed to t he large pist on piston to p will go a l ong way to go Based cr oss sectional are a of the sma ll piston is S 1 plus a sm all piston in the downwa rd pressure on the F1 T hus a small piston on th e liquid pres sure to P F1 SI Can b e the same s ize in all dir ections to th e transmissi on of liquid By the lar ge piston is also equival ent to the in evitable pres 15 sure P If th e large pisto n is the cros s sectional are a S2 the pre ssure P on t he piston in the upward pressure gen erated F2 PxS2 Cross sectional are a is a small multiple of t he piston cr oss sectional are a From the type known to add in a s mall piston of a smaller force the pist on will be in great force for which th e hydraulic machine use d to suppres s plywood oil extract h eavy objects such as for ging steel 16 The sec ret of hydra ulic systems success and widespread use is its ver satility and manageabili ty Fluid p ower is not hindered by the geometr y operations when the p otential diff erence betw een the tool and the wor k piece is su fficiently hi gh a transie nt spark disc harges throu gh the fluid removing a very small a mount of m etal from th e work piec e of the mac hine as is th e ease in me chanical sys tems Also power can b e transmitte 17 d in almost l imitless qua ntities becau se fluid syst ems are not so limited b y the physic al 1imitation s of material s as are the electrical sy stems For examplethe performance of an electr omagnet is l imited by T he saturatio n limit of ste el On the otherhandth e power limi t of fluid sys tems is 1imi ted only by t he strength capacity of t he material Industr y is going to depend mor e and more on automati on in order t o increase p 18 roductivity Thisinclude s remote an d direct cont rol of produ ction operati onsmanufac turing proce sses and m aterials hand ling Fluid power is the muscle of a utomation b ecause of ad vantages in t he following four major categories 1 The p recise conve nient control by operatin g a simple j oystick and buttons the operators of the hydrauli c system an d can imme diately start stop and de celeration a nd can provi de any powe 19 r position p recision for one over ten thousand in ch position control A m ake the pilot rises and fal l the landing gear on the hydraulic sy stem when t he pilot to a certain direc tion control valves pres sure oil into hydraulic cy linder of a c avity and ca me down on the landing gear The pil ot to move i n the opposi te direction control valv es allow the oil into the hydraulic cy linder of an other chamb er to take ba ck on the la nding gear 2 Multi 20 plication of force A fl uid power s ystem witho ut using cu mbersome g ears pulle ys and lev ers Can mul tiply forces Simply and efficiently fr om a fractio n of an ounc e to several hundred ton s of output 3 Const ant force or torque Onl y fluid powe r systems ar e capable of providing co nstant force or torque re gardless of s peed change s This is a ccomplished whether the work outpu t moves a fe w inches per hourseveral 21 hundred inc hes per min utea few rev olutions per hour or th ousands of r evolutions p er minute 4 Simplicity safety e conomy g eneral flui d power syst ems use few er moving p arts thant of high temper ature hydra ulic oil expa nsion will o ccur resulti ng in increa sed compres sion so that action can n ot be very g ood control of transmiss ion Solutio n heat is the inherent ch aracteristics of the hydra ulic system not only to minimize er 22 adication U se good qual ity hydraulic oil hydraul ic piping arr angement sh ould be avoi ded as far as possible the emergence of bend the use of high quality pipe and fittings hydraulic va lves etc 2 The v ibration of t he vibration of the hydra ulic system i s also one of its malaise As a result o f hydraulic oil in the pip eline flow o f high speed impac t and the co ntrol valve t o open the c losure of the impact of th e process ar e the reason 23 s for the vib ration syste m Strong vi bration cont rol action wi ll cause the system to er ror the syst em will also be some of the more so phisticated e quipment er ror resultin g in system failures Sol utions hydr aulic pipe sh ould be fixe d to avoid s harp bends To avoid fre quent chang es in flow di rection can not avoid da mping meas ures should be doing a g ood job The entire hydra ulic system should have good dampi ng measures while avoi 24 ding the ext ernal local o scillator on t he system 3 The l eakage of th e hydraulic system leak into inside a nd outside t he leakage Leakage ref ers to the pr ocess with t he leak occu rred in the s ystem such as hydraulic piston cylinder on both sides o f the leakag e the contro l valve spoo l and valve body such a s between th e leakage A lthough no i nternal leak age of hydra ulic fluid los s but due to leakage the control of t he establish 25 ed moveme nts may be a ffected until the cause sy stem failure s Outside m eans the occ urrence of le akage in the system and t he leakage b etween the e xternal envir onments Di rect leakage of hydraulic oil into the environment in addition to the syste m will affec t the workin g environme nt not enou gh pressure will cause th e system to t rigger a faul t Leakage i nto the envir onment of t he hydraulic oil was also the danger of fire Solut ion the use 26 of better qua lity seals to i mprove the machining a ccuracy of e quipment In the hydra ulic system and its syste m the seali ng device to prevent lea kage of the work of me dia within a nd outside t he dust and t he intrusion of foreign b odies Seals played the r ole of comp onents nam ely seals M edium will r esult in leak age of waste pollution a nd environm ental machi nery and ev en give rise to malfuncti oning machi nery and eq uipment for 27 personal acc ident Leaka ge within th e hydraulic system will cause a shar p drop in vo lumetric effi ciency amo unting to les s than the re quired press ure can not even work Micro invasive sys tem of dust particles can cause or ex acerbate fric tion hydraul ic compone nt wear and further lead to leakage Theref ore seals an d sealing de vice is an im portant hydr aulic equip ment compo nent The rel iability of it s work and l ife is a meas 28 ure of the hy draulic syste m an import ant indicator of good or bad In addit ion to the cl osed space are the use o f seals so th at two adjac ent coupling surface of t he gap betw een the need to control t he liquid ca n be sealed f ollowing the smallest ga p In the con tact seal pre ssed into sel f seal style and sel f styled self tight seal is sealed lips two 29 指 導(dǎo) 教 師 評 語 外文翻譯成績 指導(dǎo)教師簽字 年 月 日 注 1 指導(dǎo)教師對譯文進(jìn)行評閱時應(yīng)注意以下幾個方面 翻譯的外文文獻(xiàn)與畢業(yè)設(shè)計 論文 的主題 是否高度相關(guān) 并作為外文參考文獻(xiàn)列入畢業(yè)設(shè)計 論文 的參考文獻(xiàn) 翻譯的外文文獻(xiàn)字?jǐn)?shù) 是否達(dá)到規(guī)定數(shù)量 3 000 字以上 譯文語言是否準(zhǔn)確 通順 具有參考價值 2 外文原文應(yīng)以附件的方式置于譯文之后