2023年机械液压外文文献英文文献水基液压系统.docx

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1、水基液压系统A 传统上水基液压系统已经应用在钢铁厂炼铁领域。这些 产业中水基液压系统的明显的优点是它们的耐火性。并且水基液压系统在费用 上也优于油基的液压系统。一方面，无毒的、可被生物分解的综合性添加剂每加 仑花费5到6美元。一加仑集中可生成2 0加仑的5 %溶液,因此事实上水基液压 流体的费用可以比油基的每加仑少3。分。在工厂的水平下，考虑到相关费用、防止和清理环境的污染，水基液压系统拥有 节省巨大成本的潜力。液压油的泄漏已经成为一个非常重要的问题。它必须被收 集、妥善控制。但是,具有合成添加剂的水，可以倾倒入工厂的污水系统。a在工厂水平下，节省成本不断留在流体的较低成本及 其解决上。由于水

2、基液压液由十部分水和一部份合成添加剂，5加仑添加剂与 水的混合物构成10 0加仑水基流体。5。加仑的容器当然比两个55加仑的桶更 容易解决，因此储藏更简朴、更清洁、更不凌乱，运送成本也较低。其他工厂范围下潜在的节约是为工人改善安全，由于水基液是不含毒性，并且非易 燃。这些特点可以减少工厂的保险费率。泄漏的成本比清理低，由于不再需要颗 粒吸取剂或吸附棉条。水基流体再次变成“热门话题”a在20世纪70年代石油禁运引发了较低成本的水基液压流体替代高昂的液压 油的爱好。当设计师们获悉，一加仑聚合物可以制造出二十加仑的流体时，即使 是最昂贵的水添加剂都更有吸引力。4由于石油价格逐渐的回落，因此人们对水基

3、液压也没有那么大的爱好了。回想起来，对水基流体 的爱好集中在其节省成本的潜力上。当设计师发现他们不能在他们的系统中改变 流体从液压油到水的状况并且也没有其他重大的改变时，他们就失去了爱好。然 后，他们不情愿的接受其他的“缺陷”-了解到很大的变化-又切换到水基液压。4 合用于水基液压系统的不同的规则被认为是缺陷。设计师也许不乐意学习更多关 于水基液压，由于他们被暗示,所有的工作需要依靠如何设计一个新的系统或改 造旧系统的知识。由于他们结束了对这此外技术的思维，他们错过了除水基流体 materials.V a Iv e s for water ser vice a 1 s o a r e s li

4、ghtly larger thant hose f o r o i 1 . This ma y be ano t herre ason wh y w ater-base d sys t ems h a ve not gained wide acceptan c e. O r igi n ally, the la r ge r size o f c o mpo n ents for wate r ba s e d fluid cr e a t ed a h a n dica p when d e sig n i n g sy s terns, an d more costly c onstr u

5、 ction infl ate d prices of valv esfor wate r -based fluid to t h ree tim e s or m o r e that o f valves for oil. Now, howev e r, v a 1 v e s izes are compar a ble to th ose for oil. Many valves are av a ilable with s t andard NFPA footpr i nts. The p r ice different i a 1 has a Iso b e come 1 ess.

6、C o mp o nen t s fo r water-b ased flu i d st i 11 may cost p e rha p s 3% more than t ho s e for oil sy s terns, b ut this m a y b e a bar g ai n wh e ny 0 u c 0 nsid e r the cost-saving pot e nt i al of water-bas e d s yst e ms.a Fluidleakag e a L eakage continu e s to be a nag ging p robl e m i n

7、 m any hydr a u lie system s . New seal mater i al s an d de s i gns, and 0 -ring face- s e al f i tt i n g s a r e p o werf u 1 w eapons i n th e battle against 1 eakage. But the ba t tie i s fa r from o v er b e ca u se o f mi s a p p li c a t ion, impro p er i n s t a 1 1 a ti 0 n, or simple la c

8、 k 0 f unders t a n d ing. Alth 0 ugh th e re 9 ;s n 0 excuse f or leak age in mos t systems, it stil 1 o c cur s . As s umingt h at leakage wi 1 1 not b e el i min a te di n the near future,wate r -ba s ed fluid can dramat i cal 1 y re d u c e the c osts associa t ed w i th 1 e akag e .In t erna

9、l leak age ca n b e j u s t as wa s t ef u L This 1 e a k ag e can carbur i ze t h e 0 il by gen e ra t ing he a t. In t e rna 1 leaka ge t ypica 1 1 y is rou t ed ba c k to tank, s o this t e chn i que tra n sforms mechanic a 1 e n e rgy into heat i nste a d of useful w o rk. U s ing a st a inle s

10、s steel spool with PTFE seals in a v a Iv e fo r wa t er-ba s e d f 1 u id e 1 imi n ate s the n e e d for clear a nc e between m o ving compo n e n ts. Bec a u s e the r e is n o clearanc e , t here i s n o int e r n a 1 leaka g e .a But be y o n d the o b v ious and i ntangible costs o f f lu i d

11、1 e ak a g e? di s p o s i ng of the f 1 uid that has 1 eaked fro m a syst e m b e c o mes a concer n . A 1 1 o w in g h y d r a u lie o i 1 t o ente r plant eff1 uen t systems bee omesan e xpe n siv e pr o posi t ion when r e moval and dispos a 1 c osts are c o n s i dere d . Rea 1 izi n g that c 1

12、 eanup and disposal cost s w i 11 on 1 y g o up, a nd that the price o f o i 1 is unst able sug g ests tha t waterb a se d hydr a uli c s can b ea n e c on o mic a 1 s o lution t o e nvironme n t a 1 p r oblems. a初始成本以外的许多其他的优点。现在，环境问题，增长了液压油解决成本的价格, 水基液压便再次成为热门话题。抵抗凝固A当然，水基液压系统的确在应用上有它的局限性。一个限制就是潜在

13、的凝固。这个也许性也许是更广泛地应用水基系统, 特别是在移动设备业最重要的阻碍。长壁开采法是迄今为止最大的可以充足运用 水基系统的移动设备部门。地下的温度不接近水的凝点和耐火性是必不可少的条 件。用于温带气候海上设备和移动设备获利于水基系统的优点，但不能保证这些 设备将始终用在上述凝固温度。但是,给水基流体加入防冻液可以使其凝固温度远低于32华氏度。用在汽车上的 防冻液-乙二醇-是有毒的，是不能生物降解的，因此它在水基液压中添加防冻液将 击败水基液压流体在环境上的优势。A有一个替代的方法。丙二醇是没有毒性，并且是可生物降解的。它比乙二醇花费更多，并且是 不太有效的一种防冻液，因此它必须使用较高

14、浓度的溶液。减少凝固潜力的此外 两个技术是要保持流体的不断循环和在实际中使用胶管。A系统的密封A水基液 压系统的两个个容易被察觉的问题是细菌的大批出没，并且很难保持适当的浓 度。大气下的密封系统在控制中可容纳细菌成长。此外，假如从系统排除空气， 一个抗菌剂的流体能对防止细菌的增长有一个持久的影响。A 一个被密封的水箱消除许多液压系统遭受的另一个问题：水的 进入。这说明关于水基系统的另一个误解：没有从大气中密封的水基系统，必须 密切监察，以保证该添加剂浓度保持在在允许的范围之内。这是由于水比添加剂 更容易从水箱蒸发。因此，水分蒸发导致添加剂浓度增长。当新液体添加到系统 时，现有的流体样本必须采用

15、措施，以拟定一定浓度的添加剂在溶液中。这些结 果显示，添加剂在流体中的比例必须补充，使流体的浓度是合适的。与大气隔绝的密封的流体系统，事实上消除了蒸发问题。泄漏的液体是包含水和 添加剂的。所以，系统液体的量在发生变化，但浓度没有变化。系统流体通过 增长水和添加剂的一种预先混合重新补充到水箱。特殊的考虑假如水基液压系统没有对的的设计，他们也许更容易使水泵汽蚀。应提供通畅的 通道，保持流体速度低于2 0英尺/秒，最佳是在压力线低于15英尺/秒。在一 般情况下，吸油管的速度，不应超过2 -3英尺/秒。在回油管的速度应低于5到 10英尺/秒。当流体再进入水箱时，较高的回油管速度可以促进发泡。零部件也应

16、 注意其规格，由于流体压力和速度急剧变化也许导致溶解气体和导致类似气蚀的 损伤。对水基的系统的重要考虑是应当明确设计重要元件为水基流体所使用，而不是修 改最初供油服务的系统。油管，胶管，及配件，通常对这些油基液压系统可以相 同。但是，水泵，阀，执行器和供水装置，存在着一些重大不同。例如，齿轮泵, 应作出超硬合金抗磨损。泵的齿轮比一个油泵应更广泛，由于水的低粘度需要一 个更大的范围，以形成一个足够的润滑膜。使用在水基系统中的缸应当有青铜做 的活塞，以减少活塞和缸壁之间的磨损。弹簧或0型圈的密封用来减少活塞的 渗漏。水基液压阀水基的流体的阀通常是加了密封件，用于分离金属零件，以防止金属-金属接触。

17、这是由于水-甚至与润滑油添加剂-没有提供完整的润滑油膜。水基装置用的阀的价格也有少许大于油基装置的。这也许是另一个因素，水基系 统没有得到广泛的接受。本来，当设计系统时,面积较大的元件水基流体创建了一 个障碍，并且更加昂贵的制造价格使水基液压阀的价格提高了 3倍或更多。但是, 现在阀大小和油基系统的相称。许多阀可达成美国国家防火协会标准。价格差异 也较少。水基液压元件仍也许花费比油基系统高3%以上，但当考虑到水基系统 节省成本的潜力，这样做也许会得到更多的实惠。A流体的泄露在许多液压系统中泄漏仍然是一个恼人的问题。新的密封材料及设计，及0型圈, 是解决密封装置泄漏的功能强大的武器。由于误用，安

18、装不妥，或缺少简朴的了 解，泄漏的问题仍未解决。虽然在大多数的系统中没有任何理由泄漏，但它仍然 出现。假设不解决泄漏，在不久的将来，水基液可以大大减少泄漏的相关费用。内部泄漏是很浪费的。这种泄漏能能使温度升高,从而使液压油碳化。内部泄漏 通常是泄露回容器的，因此这一技术转化成机械能的热，这并不是有益的工作。 在一个水基液压阀运动部件中采用不锈钢阀芯聚四氟乙烯密封。由于没有间隙， 所以就不存在内部泄漏。A但除了明显的和无形的液漏成本外,解决已泄漏液体已经成为一个被人关注的问题。考虑到除去或取消成本时，允 许液压油进入污水厂系统成为一个昂贵的主张。实现这一清理和处置成本只会上 升，并且石油价格的不

19、稳定表白,水基液压可以成为一个利于解决环境问题比较经 济的办法。小 Water-base d h ydra u 1 i c sys t em s a W a te r base d h ydraul i c s y stem s t r a dit i onall y ha v e been u s e d i n hot-m etal are a s o f steel mi 1 Is. Th e o b vi o u s ad v antage o f water s y st e m s i n these i ndustrie s is th e ir fire r esist a n

20、ee. W a t e r-ba s e d hy d ra u 1 i c s ystems also h a v e o b vious cost ad v ant ages over o i 1 -b a sed f 1 uid. Fi r st, n o n- t o xic, b i o d eg r a d a b le sy n theti c a d diti v e s for wat e r cost $ 51 o $6 per g a 1 Ion. One g allon o f con c e n trate can m a ke 2 0 g allons of a 5

21、% sol u tion, s o the c ost 0 f water-ba sed hyd r a u 1 ic fluid a c t u a 11 y ca n be 1 e ss t han 30 cents per gallon.Con sider in g the c 0 sts a sso c iate d with p re v enting and c 1 eanin g up en v iro n men t a 1 contaminatio n , waterb a s e d hydraulic s ystems hold the potentia 1 for tr

22、emend 0 us cost sa v ings at th e p 1 ant 1 evel. Oil th a t h as leak e d a 1 ready b ecome s a ve r y im p o r ta n t p r ob 1 e m. It must be coll e c ted, p r o p er 1 y con tained. W a ter cont a ining s y n t h e t ic addi t ive s , howev e r, c a n by dumped in t o p 1 a n t e ffluen t s y st

23、em s .C o st sa v ings at the pla n t le v el don'；t stop at t he 1 ower c o st o f the flui d an d it s disp o s a 1 , Becau s e w a ter- b a se d h y drauli c fl u i d c on s i s ts of io parts w a ter a n d on e part s ynt h etic addi tive, 5 g a llo n s of a d d i t ive mixe s with wat e r to

24、 m a ke 1 0 o g a 1 1 o n s of water-b a s e d f 1 uid. A 5 o g a lion c ontain e r is cer t ai n ly easier to hand 1 e than two 55- g al 1 o n d rums, so w a reh 0 u s ing is s i mple r , cleaner, a n d 1 e ss cluttered. T r a nsport a t i on costs al s o are lowe r .Other p o t e ntial plantw i d

25、e s a vi n gs i nc 1 ude im p ro v e d s a fety f or wor k e rs b ec a u s e the waterbased fl u i d i s n 0 n-to x ic as w e 1 1 as n on- f lam m able. T h ese attribu t es can reduce plant insuran c e rate s . Spil 1 s cost les s to c 1 ea n up beca use gran u lar a bs 0 rb e n t s or a b sor b en

26、t socks are unnecessary. Wate r is &qu 01； h ot& q uot； againT h e o i 1 embargo in the 197 Ossparked in t erest i n wate r b ased flu i ds as a less- c ost 1 y alternat i v e to oils. E v en t he mo s t exp e n s i v e wat e r addit i ve s b ecam e attr a ctive wh e n design e r s 1 e arned t ha t

27、one gallon 0 f cone e n t rat e woul d mak e 2 o gallons of f lu i d.A s 0 il price s gradua 1 1 yd r opped,s 0 d id int e re stin w a ter-based hyd r aulic s . I n re t r ospe ct , i ntere s t inwa t e r -ba s e d fl u ids c ent e re da r oun dtheir cos tsavi n gpotenti a 1. Most desig n e r s 1 os

28、tinteres twhen t hey d i s covere d that t h ey could n ot just c h a nge the flui d i n thei r syst e ms from oi 1 t o water witho u t mak i ngothersub sta n tial changes. Th e y t hen bee o me rel u eta n t to acc e pt o ther "dis a dvan t a ge s &quo t ； - read substa n ti a 1 chan g es - of

29、 s w i tching o v er t o w a te r -base d hy d ra u 1 i c s .Wh a t were v i ewed a s d i sadvanta g e s w ere real 1 y diffe r ent rule s that ap p ly to wate r - b ased hydra u 1 ic systems ? Designers p r obab 1 y res i s t e dl e arni n g m o re about waterbased h ydraulics b e cause they were i

30、nt i m a t e d by all the w ork r e qu ired to lea n a bo u t how to d es i gn a ne w sy s t e m or r e tr o fi t an o 1 der sy s tem. By c 1 o sing th e ir minds to t h is d i ffe r e n t tech n olo g y , th e y mis s ed t he ma n y other adv a n t a ge s o f water-based fl u id b eyon d initia 1 c

31、ost. Now tha t e n v ironmen t al c oncerns hav e added disposal c osts to the price o f hydr a ulic flu ids, w ate r -based hy d raulics has a g ain b ecome a h ot t o pic.F i ghting f r e e zea Wa te r - b ased hydra ulic systems d o , of cou r s e , have limits to t h ei r a ppi i ca t i ons. One

32、 1 im i tatio n i s the p o t en t ial of freez i ng. This p o ssib i 1 it y is pr o ba b ly the mo s t signifi c ant bio c k a d e to m o r e w i des p read appl i c a ti o n of water-b a sed systems, e s pe c i a lly in t he mo b ile e q uipment industr y . Lon g wall mi n i ng is by far t he lar

33、g est sector of mobil e equi p ment that has b e en a b le to ta k e advantag e o f wate rbased s y s t e ms. Tem peratures und e rg r ound do not a p p roac h the freez ing point of wat e r, and fir e resistanc e is esse n tial. Mobile and even mar i n e e q u i p m e nt us e d i n tempera t e clim

34、at e s cou 1 dcash i n one the adv a n tages o f w a ter b a s ed sys t ems, b ut t here is no g u a r a ntee that such equ i pme nt a 1 w ays w i 11 be use d in ab o ve-fr e ezing t emp e ratu r esq Neverth e le s s , addi n g a n anti-freez e to a w a te r -based fl u id c a n de p r e s s i t s f

35、ree z in g temp era tur e t o we 1 1 below 32F. E t h yl e ne glycol - u s ed in automoti v e ant i freeze - is toxic and i s n ot biodeg r adabl e , so it s use for a nt i freez e i n wate r b a s ed hydraulic f 1 u id w o uld d e feat t h e e n vir o nme n tai advantage wat e rbas e d fl u id has.

36、 4 T h ere is ana 1t e rnat i v e . P r o pyl e neglyc o 1 i snot t oxic an d isb i o de gradable. It co s ts mo r ethanet hyl e neg 1 yc o 1a nd i s not qui t ease ffe c tive a nti f r e e z e,so i t m ust b e used in slightly hi g he rconcentr a tions. T wo moretechniqu e s to redu c e freezing p

37、o t e nti a 1 a re to ke e p f 1 u i d c ircul a t i ng c on t i nu o usly and us e hose wher e p r actical Sealing the sys t emTwo more perceived p r o b 1 ems w i t h w a ter hyd r a ulic sys t ems are bacte r ial i nfestatio n and d i ffi c ult y i n ma i n t ain proper c on c entrations. S e ali

38、ng the system f r om atmos p h er e canhoi d bac t erial g r ow t h in check. A d ditio n o f an a n ti- b acterial a gent to the flui d can have a las t i n g e f fee t on p r e v e n ting b a ct e r ial bu i Idup if a ir i s ex c luded f r om t h e sys t e m.a A sea led r eserv o i r e 1 i mina te

39、s anot her p ro b lem suffered by m a ny hydra uliesy stems: wa t er i ngre s s i o n. This a d d res s e s an other mis c onceptio n about water-b a se d sy s t em s ： water-ba s ed systems not sealed from the atmosph e re must be cl o sely m onitored t o ensu r e that t h e add i tiv e c o nc e n

40、t rati o n s t ays with i n toleran c e . Th a t i s b e ca u se water ev a po r ate s from the res e rv o ir more rea d ily th a n the ad d itive does. C o n s e q u ent 1 y, w a ter evaporation cau s es the additive co n c entratio n to i ncrease. W h en new fl u id is adde d t o a s y s tern, s a

41、 mples of t h e exis t i ng fl u i d must be t a k en to determine t h e c o nee ntr a tion o f additiv e in s oluti o n . These r esu 1 ts then r e veal the r atio o f addi t i v e to flu i d tha t mu st b e adde d s o t ha t f 1 uid c oncen t ration i s c o rrect.With a sy s tem that s e al s flui

42、d from the atmo s phere, t he e va p orat i o n p rob 1 em i s virt u all y el i minated. F 1 uid th at escapes by 1 e akage i s a s o 1 u tion c o n t a i ning wa t er a nd add i tive. Ther e fore, t h e qu a ntit y o f fluid in th e s y stem changes, b u t c o ncentra t ion doe s n ot. System f 1

43、uidi s re p leni s h ed s imply b y addi n g a premixed soluti o n of wate r an d addi t ive to the reservoir.Speci a 1 c o nsid era tionsWa t e r-based h yd r a u lie s y s terns ca n be more prone to pump ca v itation i f they are not pro p er 1 y d es i gned. Gen e rous por t ing and o t he r pas

44、 s ageways s houl d be provided to keep fluid veloci t i es b e 1 ow 2 0 f t /s e c - pre f erabl y , be 1 ow 15 ft/ sec in pre ssure lines. V el o ci t y in suction 1 ines, i n ge n e r a 1 , s h o u Id n ot exceed 2 -3 ft/s e c. Ve 1 ocities i n r etu r n 1 ines s h ould be he 1 d below 5-ioft/s e

45、 c. Higher return v eloc i ties ca n promo t e f 0 ami n g whe n fluid r e- e nters th e r eservoir. C ompone nts s hou Id als o be c arefu 1 1 y s i z e db e c ause rapid cha n g esi nf 1 uid pr e s s urea nd v e lo c i t ycan c aus e d issol v eda ir to pr e c i p i t a te fro m s olut i on an dca

46、us e damagesimil a r to tha tpr o du c ed byca v i ta t i o n s.aAn imp o rtan tc o nsider a ti o nfor wate r -basedsystems is that majo r compo n e n t s should be de sign edsp ecifica1 1 y fo r u se wi t h wate r f 1 uid, r a th e r t han modi f i e d from ve r s i ons ori g ina 1 ly i ntend e d f

47、 or oil s er vi ce.Tub i n g ,hose, a n d fit t ing s usually can b ei dentica 1t otho s ef oroil s y s tem s . P u m p s, va 1 v e s, and a ct u a tor sf orwate rs ervic e, howeve r , exhibit s o me si g n ificantdiff e re n ce sfrom com po nen t s for oi 1 syst e ms. Pump gea r s, for exampl e ,sh

48、ould b e made of super-hard a 1 1 oys to r e sist w e ar. A pump'；s g ear fa c e s ho u 1 d be w i der tha n that o f an o i 1 pump b e cause wate r '；s low vi s cosit y r equ i r es a la r g e r a rea t o f orm an ad e quat e lu b ric a nt fi 1 m. Cylin d ers used in w a ter s y stems s hould

49、 have br o n z eclad pisto n s to mi n im i z e wear betw e e n pi s tons and c y linder walls. S pring- or Or i n g -en e rg i z ed seals s hould b e us e d t o minimize lea k age a c ros s t h e piston.Vai v es for w a ter V a 1 v es for wa t er-based flui d u sually are p a eked with seal s s e p a ra t ing me t a 1 p art s to p r event metal- t o-me t al cont a ct. T h is is b e ca u se wa ter- even wit h lubr i can t addi t ive s does n ot pr o v ide the full-f i