外文翻譯--液壓系統(tǒng)的動(dòng)力源-泵和蓄能器

1、<p><b>　　附 錄</b></p><p><b>　　外文文獻(xiàn)原文：</b></p><p>　　The commonly used sources of power in hydraulic systems are pumps and accumulators .</p><p>　　Simil

2、arly,accumulator connected to atmosphere will dischange oil at atmosphere pressure until it empty. only when connected to a system having resistance to flow can pressure be developed.</p><p>　　Three types o

3、f pumps find use in fluid-power systems:rotary,reciprocating or piston-type, and 3,centrifugal pumps.</p><p>　　Simple hydraulic system may use but one type of pump . The trend is to use pumps with the most

4、satisfactory characteristics for the specific tasks involved . In matching the characteristics of the pump to the requirements of the hydraulic system , it is not unusual to find two types of pumps in series . For exampl

5、e , a centrifugal pump may be to supercharge a reciprocating pump , or a rotary pump may be used to supply pressurized oil for the contronls associated with a reversing variabledisplace</p><p>　　1、Rotary pum

6、ps</p><p>　　These are built in many differnt designs and extremely popular in modern fluid power system . The most common rotay-pump designs used today are spurgear , internal gear ,generated rotor , sliding

7、 vane ,and screew pumps . Ehch type has advantages that make it most suitable for a given application .</p><p>　　2、Gear pumps</p><p>　　Gear pumps are the simplest type of fixed displacement hyd

8、raulic pump available . This type consists of two external gear , generally spur gear , within a closed-fitting housing . One of the gear is driven directly by the pump drive shaft . It ,in turn , then drives the second

9、gear . Some designs utilize helical gears ,but the spur gear design predominates . Gear pumps operate on a very simple principle . As the gear teeth unmesh , the volume at the inlet port A expands , a partial vacuum on

10、t</p><p>　　3、Vane pumps</p><p>　　The vane pump consists of a housing that is eccentric or offset with respect to the drive shaft axis . In some models this inside surface consists of a cam ring

11、that can be rotated to shift the relationship between rotor are rectangular and extend radially from a center radius to the outside diameter of the rotor and from end to end . A rectangular vane that is essentially the s

12、ame size as the slot is inserted in the slot and is free to slide in and out . </p><p>　　As the rotor turns , the vanes thrust outward , and the vane tips track the inner surface of the housing , riding on

13、a thin film of fluid . Two port or end plates that engage the end face of the ring provide axial retention . </p><p>　　Centrifugal force generally contributes to outward thrust of the vane . As they ride alo

14、ng the eccentric housing surface , the vane move in and out of the rotor slots . The vane divide the area between the rotor and casing into a series of chambers .The sides of each chamber are formed by two adjacent vanes

15、 ,the port or end plates , the pump casing and the rotor . These chambers change in change in volume depending on their respective position about the shaft .</p><p>　　As each chamber approaches the inlet por

16、t , its vanes move outward and its volume expands , causing fluid to flow into the expanded chamber . Fluid is then carried within the chamber around to the dischange port . As the chamber approaches the discharge port

17、, its vanes are pushed inward ,the volume is reduced , and the fluid is forced out the discharge port .</p><p>　　Vane pump speed is limited by vane peripheral speed . High peripheral speed will cause cavitat

18、ion in suction cavity . which results in pump damage and reduced flow .</p><p>　　An imbalance of the vanes can cause the oil film between the vane tips and the cam ring to break down , resulting in metal-to-

19、metal contact and subsequent increased wear and slipage . One metheod applied to eliminate high vane thrust loading is a dual-vane construction .</p><p>　　4、Piston-type pump </p><p>　　All piston

20、 pumps operate by allowing oil to flow into a pumping cavity as a piston retreats and then forcing the oil out into another chamber as the piston advances . Design differences among pumps lie primarily in the methods of

21、separating inlet from outlet oil .</p><p>　　5、In-line piston pump</p><p>　　The siplest typeof axial piston pump is the swash plate in-line design .The cylinder are connected though piston shoes

22、and a retracting ring , so that the shoes beat anainst an angled swash plate . As the block turns ,the piston shoes follow the swash plate ,causing the piston to reciprocate . The ports are arranged in the valve plate so

23、 that the pistons pass the inlet port as they are being pulled out and pass the outlet port as they are being forcing back in .</p><p>　　The angle of the swash plate controls the delibery . Where the swash p

24、late is fixed , the pump is of the constant-displacement type . In the variable-displacement , inline piston pump , the swash plate is moumted on a pivoted yoke . As the swash plate angle is increased , the cylinder stro

25、ke is increase , resulting in a greater flow . A pressure compensator control can position the yoke automatically to maintain a constant output pressure . </p><p>　　6、BENT-axis piston pump</p><p&g

26、t;　　As the shaft roates , distance between any one piston and the valving surface changes continually . Each piston moves away from the valving surface during one half of the revolution and toward the valving surface dur

27、ing the other half . The inlet chamber is in line as the pistons move away , and the outletr chamber is in line as the pistons move closer , thus drawing liquiring in during one half of the inlet chamber as the pistons a

28、re moving away from the pintle . Thereforce , during rotation ,</p><p>　　7、Pump/system interaction</p><p>　　Pressure-compensated variavle delivery pumps do not require a relief valve in the hig

29、h pressure line . The pressure compensation feature eliminates the need for the relief valve . In nearly all working systems ,however , at least one is used on just-in-case basis . The use of a pressure compensator , whi

30、le avoiding dependence on a relief valve , brings on its own problems . The actuator -spring-spool arrangement in the compensator is a dynamic , damped-mass-spring arrangement . However , when th</p><p>　　Va

31、ne pump speed is limited by vane peripheral speed . High peripheral speed will cause cavitation in suction cavity , which results in pump damage and reduced flow . An imbalance of the vanes can cause the oil film between

32、 the cane tips and the cam ring to break down , resulting in metal-to-metal contact and subsequent increased wear and slipage . One method applied to eliminate high vane thrust loading is a dual-vane construction . In th

33、e dual-vane construction , tow independent vanes are loca</p><p>　　Centrifugal force cause the vane to follow the contour of the cam-shaped ring .There is just sufficient seal between the vanes and ring wit

34、hout destroying the thin oil film . </p><p><b>　　外文文獻(xiàn)中文翻譯：</b></p><p>　　常用的液壓系統(tǒng)的動(dòng)力源是泵和蓄能器。</p><p>　　一般情況下，一個(gè)蓄能器在正常的大氣壓力下，連續(xù)的向各系統(tǒng)中壓入液壓油，直至將所儲(chǔ)存的能量全部用完為止。 只有當(dāng)其連接的系統(tǒng)中，具有抗流壓力

35、時(shí)才能夠得到補(bǔ)充。</p><p>　　在液壓系統(tǒng)和液力系統(tǒng)中，常使用液壓泵有回轉(zhuǎn)式、往復(fù)式、活塞式或者離心式三種類型： </p><p>　　簡(jiǎn)單液壓系統(tǒng)一般使用的都是第一類液壓泵。 目前的發(fā)展趨勢(shì)是針對(duì)具體的工作任務(wù)和工況，選用最佳的液壓泵類型。在符合特性和要求的液壓泵中，找到兩種不同類型的液壓泵式很常見的。 例如，離心泵，往復(fù)泵都可以可對(duì)系統(tǒng)增壓，旋轉(zhuǎn)泵和變量液壓泵聯(lián)合使用也可以提供

36、高壓的液壓油。 大部分動(dòng)力系統(tǒng)還需要采取容積式液壓泵泵。而在較高的體統(tǒng)壓力下，往復(fù)泵往往要優(yōu)于回轉(zhuǎn)泵。 </p><p><b>　　1、回轉(zhuǎn)泵</b></p><p>　　這些形式的液壓泵因?yàn)榫哂性S多不同的設(shè)計(jì)形式而極受歡迎，在現(xiàn)代流體動(dòng)力系統(tǒng)。 最常見的旋轉(zhuǎn)泵的設(shè)計(jì)形式，包括內(nèi)部使用齒輪的、內(nèi)部使用轉(zhuǎn)子的、內(nèi)部采用滑動(dòng)葉片的和使用螺桿的。 其中，每一種類型都有其獨(dú)

37、特的優(yōu)點(diǎn)，都有其最適合的一定的應(yīng)用場(chǎng)合。</p><p><b>　　2、齒輪泵</b></p><p>　　齒輪泵是可以提供的最簡(jiǎn)單的一種液壓泵。 這一類型的液壓泵一般包括兩個(gè)外嚙合的齒輪，一般是圓柱直齒輪，安裝在一個(gè)密封的殼體里面。 其中一個(gè)齒輪由液壓泵的傳動(dòng)軸直接驅(qū)動(dòng)， 第一個(gè)齒輪然后再推動(dòng)第二輪。還有一些設(shè)計(jì)中利用螺旋齒輪，但是一般以齒輪設(shè)計(jì)為主。 齒輪泵的動(dòng)

38、作的原理非常簡(jiǎn)單，如插圖7.3 所示。 由于在齒輪的輪齒在脫開嚙合時(shí)，進(jìn)氣道擴(kuò)大， 液壓泵將會(huì)形成局部真空的具有吸力的空腔。 流體在系統(tǒng)的壓力下被從外部油箱或罐體中壓入， 連續(xù)運(yùn)動(dòng)的液壓油在液壓泵的作用下，從真空的吸力空腔中被送入排出液壓油的一側(cè)——B側(cè)。</p><p><b>　　3、葉片泵</b></p><p>　　葉片泵一般是由一個(gè)相通的腔體，是偏心或抵消對(duì)

39、傳動(dòng)軸軸線。在一些模型內(nèi)的表面設(shè)有一個(gè)凸輪環(huán)，一個(gè)可旋轉(zhuǎn)移動(dòng)的長(zhǎng)方形的轉(zhuǎn)子，轉(zhuǎn)子的徑向延長(zhǎng)，從一個(gè)中心，半徑為外徑的轉(zhuǎn)子，到末端結(jié)束。 上面是尺寸大小相同的插槽，矩形葉片一般插入到插槽中，并且可以自如的滑入和滑出。</p><p>　　當(dāng)轉(zhuǎn)子轉(zhuǎn)動(dòng)時(shí)，葉片被向外甩出， 而葉片尖端則貼緊其運(yùn)動(dòng)軌道空腔的內(nèi)表面， 處于液壓油的薄膜的上面。 兩個(gè)油口或端板，向環(huán)形的端面提供軸向的存儲(chǔ)。 </p><p

40、>　　通常離心有助于葉片的向外推出。當(dāng)葉片處于偏心空腔的表面上時(shí)，葉片從轉(zhuǎn)子的縫隙中甩出和甩。 葉片將套管和轉(zhuǎn)子之間的區(qū)域分成一系列的小空腔。每一個(gè)小空腔都是由兩個(gè)相鄰葉片，油口或者端盤，液壓泵殼體和轉(zhuǎn)子形成。 這些空腔的容積的變化取決于他們相對(duì)于軸的相對(duì)位置。</p><p>　　當(dāng)每個(gè)廳內(nèi)靠近進(jìn)內(nèi)氣孔的時(shí)候，其葉片向外移動(dòng)，其空腔的容積膨脹， 造成液壓油流入擴(kuò)大空腔。 流體隨后被帶入圍繞著排油孔的空腔內(nèi)

41、。當(dāng)這些空腔靠近排油孔時(shí)，葉片被甩入腔內(nèi)，空腔的容積減小，液壓油隨即被壓出排油孔。</p><p>　　葉片泵的速度一般要受到葉片圓周速度的限制。 過高的圓周速度將導(dǎo)致空腔內(nèi)出現(xiàn)負(fù)壓，從而導(dǎo)致液壓泵損壞和流量減小。 </p><p>　　一個(gè)不平衡的葉片將會(huì)引起葉片頂端和凸輪環(huán)之間的油膜的破壞，從而進(jìn)一步導(dǎo)致金屬和金屬之間的直接接觸，因而增加了磨損和葉片泵的動(dòng)力傳動(dòng)損耗 。消除這種葉片泵的

42、葉片的高推力負(fù)荷的方法之一就是采用雙葉片結(jié)構(gòu)。</p><p><b>　　4、活塞式泵</b></p><p>　　所有的活塞式液壓泵的運(yùn)行原理，都是通過液壓油流入泵腔而推動(dòng)活塞向后面移動(dòng)，然后活塞再向前移動(dòng)，從而將液壓油排出，使得液壓油進(jìn)入泵的另一個(gè)腔室中。 不同的泵的設(shè)計(jì)差異泵主要在于活塞進(jìn)入和推出從而將液壓油分離的方法。</p><p>

43、;<b>　　5、直軸式柱塞泵</b></p><p>　　最簡(jiǎn)單的軸向柱塞泵是將沖板進(jìn)行線性化設(shè)計(jì)。氣缸與活塞的回縮盤之間相連， 使移動(dòng)的回縮盤成傾斜式。 當(dāng)傾斜圓盤轉(zhuǎn)動(dòng)的時(shí)候，柱塞的端腳斜盤上運(yùn)動(dòng)，從而使得活塞桿不斷的往復(fù)的運(yùn)動(dòng)，同時(shí)因?yàn)橛涂诜謩e安排在閥板上，能夠使活塞通過進(jìn)氣道，當(dāng)它們運(yùn)動(dòng)到一定的位置時(shí)，通過油口將液壓油推出排油口。 </p><p>　　斜盤的

44、傾斜角度決定了柱塞泵的排量。在這里，斜盤的位置是固定的，而泵的位移是恒定的。 在變量的線性柱塞泵中，逆止閥活塞泵，沖板是裝在一個(gè)鉸鏈的枷鎖。 由于沖板角度的增大，氣缸沖程增加，形成了更大的流量。 由于壓力補(bǔ)償控制位置的作用，自動(dòng)保持恒定輸出壓力。 </p><p><b>　　6、斜軸式柱塞泵</b></p><p>　　一個(gè)普遍的鏈接鍵缸體的傳動(dòng)軸一定要保持對(duì)準(zhǔn)，并

45、且要保證他們一起轉(zhuǎn) 。缸體和克服阻力的旋轉(zhuǎn)座因?yàn)榧铀俨粋鬟f力矩而使得液壓油充入空腔。 同時(shí)，由于軸的旋轉(zhuǎn)，其距離任何一個(gè)活塞和閥門表面的距離在不斷變化。 每個(gè)活塞逐漸遠(yuǎn)離閥門的表面，直到達(dá)到總路程的一半時(shí)產(chǎn)生了質(zhì)的變化。進(jìn)油室是呈線性的遠(yuǎn)離線為活塞， 而出油室則是線性的向活塞靠攏， 因此所繪制出的流體都是在進(jìn)氣道空腔內(nèi)的中間處遠(yuǎn)離活塞 。這一期間，活塞輪換提取液壓油進(jìn)入缸孔，他們通過進(jìn)氣道的一側(cè)和高壓力使液壓油流出鉆孔，同時(shí)，它們通過插

46、座一側(cè)的樞軸，這種泵的位移隨著偏移角的變化而變化， 其最大角度為30度，最低為零。 固定位移模式通常每周以23度的傾角。 在變排量施工的枷鎖與外聘 控制是用來改變角度。 一些控制，枷鎖可以移到中心逆向流動(dòng)的方向由泵。 </p><p>　　7、泵/系統(tǒng)頻繁互動(dòng)</p><p>　　壓力補(bǔ)償式變量泵不需要在高壓線路安裝溢流閥。 壓力補(bǔ)償功能也不需要安全閥。 在幾乎所有的工作系統(tǒng)中，一般至少有

47、一個(gè)是用屬于特殊的情況。 使用壓力補(bǔ)償，同時(shí)避免依賴溢流閥而帶來的系統(tǒng)本身的問題。 動(dòng)力-彈簧閥芯排列中的補(bǔ)償是動(dòng)態(tài)的，即阻尼-彈簧-安裝排列。其落點(diǎn)量達(dá)到進(jìn)氣道， 最高流體體積就能夠達(dá)到。如果空腔和轉(zhuǎn)子之間的關(guān)系發(fā)生了改變，空腔會(huì)調(diào)整自己的流量，其最低流量一般為零。當(dāng)葉片到達(dá)進(jìn)氣道時(shí)，液壓泵的輸送量將減少到零。</p><p>　　葉片泵的速度是有限的，其速度決定于葉片轉(zhuǎn)動(dòng)時(shí)的圓周速度。 過高的圓周速度將導(dǎo)致空

48、腔內(nèi)產(chǎn)生負(fù)壓，從而導(dǎo)致液壓泵的損壞，也會(huì)導(dǎo)致流程的縮短。一個(gè)失去平衡的葉片能造成葉片的尖端和凸輪環(huán)之間的油膜被破壞，從而導(dǎo)致金屬和金屬的直接接觸，因而增加了磨損和動(dòng)力傳遞的損耗。用于消除高壓葉片的推力負(fù)荷的一種方法就是采用雙葉片構(gòu)造。在雙葉式構(gòu)造中， 每一片獨(dú)立的葉片設(shè)置在相應(yīng)的每個(gè)飛輪插槽的邊沿線兩側(cè)和頂部之間。</p><p>　　離心力造成葉片隨著凸輪形盤的輪廓轉(zhuǎn)動(dòng)、變化。因此能夠有足以密封性能， 葉片之間