壓(ya)(ya)套機液(ye)壓(ya)(ya)傳(chuan)動(dong)(dong)有機械(xie)傳(chuan)動(dong)(dong)和電(dian)力(li)拖動(dong)(dong)系(xi)統(tong)無法(fa)(fa)比(bi)擬的優(you)點技術無法(fa)(fa)比(bi)擬的優(you)點.液(ye)壓(ya)(ya)元件(jian)的布置(zhi)(zhi)不受嚴格(ge)的空間(jian)位(wei)置(zhi)(zhi)限制(zhi)(zhi)(zhi)(zhi)，系(xi)統(tong)中個部分用管(guan)道連接(jie)，布局安(an)裝有很(hen)大的靈活(huo)性，能構(gou)成(cheng)用其他(ta)方法(fa)(fa)難(nan)以(yi)組成(cheng)的復雜系(xi)統(tong)。液(ye)壓(ya)(ya)傳(chuan)動(dong)(dong)系(xi)統(tong)可以(yi)在運行過程(cheng)中實(shi)現(xian)大范圍的無級(ji)調速。另外液(ye)壓(ya)(ya)傳(chuan)動(dong)(dong)傳(chuan)遞運動(dong)(dong)均勻平穩(wen)，易(yi)于(yu)(yu)實(shi)現(xian)快速啟(qi)動(dong)(dong)、制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)和頻繁的換向。除(chu)此以(yi)外，液(ye)壓(ya)(ya)傳(chuan)動(dong)(dong)系(xi)統(tong)操(cao)作控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方便、省力(li)，易(yi)于(yu)(yu)實(shi)現(xian)自(zi)動(dong)(dong)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)、中遠程(cheng)距離(li)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)、過載保護。與電(dian)氣控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)、電(dian)子控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)相結合，易(yi)于(yu)(yu)實(shi)現(xian)自(zi)動(dong)(dong)工(gong)作循環和自(zi)動(dong)(dong)過載保護。 而且液(ye)壓(ya)(ya)元件(jian)屬機械(xie)工(gong)業基礎件(jian)，標準(zhun)化和通(tong)用化程(cheng)度較高，有利于(yu)(yu)縮短機器(qi)的設計、制(zhi)(zhi)(zhi)(zhi)造周(zhou)期(qi)和降低制(zhi)(zhi)(zhi)(zhi)造成(cheng)本。 

壓套機液壓傳動(dong)突出的優點還有單(dan)位質(zhi)量輸出功率大，以空氣為工作介質(zhi)，處理方便(bian)，無介質(zhi)費用(yong)、泄露污染環境(jing)、介質(zhi)變質(zhi)及補充等(deng)問(wen)題(ti)。 

由(you)(you)于壓套機液(ye)(ye)壓傳(chuan)動(dong)(dong)是封閉的，多數情(qing)況下其元件(jian)均可由(you)(you)傳(chuan)動(dong)(dong)液(ye)(ye)壓自行潤(run)滑，因此(ci)磨損很小.液(ye)(ye)壓元件(jian)體積小、重量輕、標準(zhun)化(hua)程度(du)高，便于集中大(da)批量生產，加上近年發展(zhan)起來的疊裝、插裝技術，裝配(pei)也(ye)很容(rong)易，因此(ci)造(zao)價低，比起其他(ta)機械傳(chuan)動(dong)(dong)，液(ye)(ye)壓傳(chuan)動(dong)(dong)有優勢。 

壓套機液(ye)(ye)(ye)壓傳(chuan)動(dong)(dong)是(shi)由17世(shi)(shi)紀(ji)帕(pa)斯(si)卡(ka)提(ti)(ti)出的(de)靜(jing)壓傳(chuan)遞(di)原理、18世(shi)(shi)紀(ji)末英國制造(zao)出世(shi)(shi)界上(shang)第(di)一(yi)臺水(shui)壓機開始發(fa)展(zhan)起來(lai)的(de)，但液(ye)(ye)(ye)壓傳(chuan)動(dong)(dong)在工(gong)業(ye)(ye)上(shang)被廣泛采用和(he)(he)有(you)較大(da)幅度(du)的(de)發(fa)展(zhan)卻是(shi)本世(shi)(shi)紀(ji)中期以后(hou)的(de)事情，特別(bie)是(shi)被20世(shi)(shi)紀(ji)第(di)二(er)次(ci)世(shi)(shi)界大(da)戰(zhan)期間戰(zhan)爭的(de)激勵(li)，取得了(le)很大(da)進(jin)展(zhan)，整體上(shang)經歷了(le)開關控(kong)(kong)制，伺(si)服(fu)控(kong)(kong)制，比例控(kong)(kong)制3個階段。比例控(kong)(kong)制技(ji)術是(shi)20世(shi)(shi)紀(ji)60年代(dai)末人們開發(fa)的(de)一(yi)種(zhong)可靠，廉(lian)價，控(kong)(kong)制精(jing)度(du)和(he)(he)響應(ying)特性(xing)，均能滿足工(gong)業(ye)(ye)控(kong)(kong)制系(xi)統實(shi)際需要(yao)的(de)控(kong)(kong)制系(xi)統。當(dang)時(shi)，點(dian)液(ye)(ye)(ye)伺(si)服(fu)技(ji)術已日(ri)益完善，但電液(ye)(ye)(ye)伺(si)服(fu)閥(fa)成(cheng)(cheng)本高，應(ying)用和(he)(he)維(wei)護條件苛刻，難以被工(gong)業(ye)(ye)界接受。希望有(you)一(yi)種(zhong)廉(lian)價，控(kong)(kong)制精(jing)度(du)能滿足需要(yao)的(de)控(kong)(kong)制技(ji)術去替代(dai)，這種(zhong)需求背(bei)景導致了(le)比例技(ji)術的(de)誕(dan)生和(he)(he)發(fa)展(zhan)。隨(sui)著(zhu)液(ye)(ye)(ye)壓機械自動(dong)(dong)化程度(du)的(de)不斷提(ti)(ti)高，液(ye)(ye)(ye)壓元(yuan)件應(ying)用數(shu)量急劇增加，元(yuan)件小(xiao)型(xing)化、系(xi)統集成(cheng)(cheng)化是(shi)發(fa)展(zhan)趨勢。 

壓(ya)(ya)(ya)套機液(ye)(ye)壓(ya)(ya)(ya)控(kong)(kong)(kong)制閥(fa)在液(ye)(ye)壓(ya)(ya)(ya)系(xi)統(tong)中(zhong)被(bei)用來控(kong)(kong)(kong)制液(ye)(ye)流的(de)(de)壓(ya)(ya)(ya)力(li)、流量和方向(xiang)，保(bao)證執行元(yuan)件按照負載的(de)(de)需求進(jin)行工作。電液(ye)(ye)比(bi)例閥(fa)是(shi)比(bi)例控(kong)(kong)(kong)制系(xi)統(tong)中(zhong)的(de)(de)主要功率放大(da)元(yuan)件，它可以根(gen)據輸(shu)入(ru)的(de)(de)電信號(hao)大(da)小(xiao)連(lian)續(xu)地成比(bi)例地對液(ye)(ye)壓(ya)(ya)(ya)系(xi)統(tong)的(de)(de)參(can)量實(shi)現遠距離控(kong)(kong)(kong)制、計算機控(kong)(kong)(kong)制，與伺(si)服控(kong)(kong)(kong)制系(xi)統(tong)中(zhong)的(de)(de)伺(si)服閥(fa)相比(bi)，在某些方面(mian)還有(you)一定的(de)(de)性 

能差距，但它(ta)顯著(zhu)的優點(dian)是抗污染(ran)能力強，大大地減(jian)少可(ke)由污染(ran)而造成的工作故障(zhang)，提高(gao)了液壓系(xi)統的工作穩定(ding)性(xing)和可(ke)靠(kao)性(xing)；另一(yi)方(fang)面(mian)比例閥的成本比伺服閥低，結構也簡單，已或(huo)得了廣泛的運用。 

比(bi)例閥(fa)(fa)按(an)主要功能分類，分為壓力控制(zhi)(zhi)閥(fa)(fa)，流量控制(zhi)(zhi)閥(fa)(fa)和方向控制(zhi)(zhi)閥(fa)(fa)三(san)大類，每一類又(you)可以分為直(zhi)接控制(zhi)(zhi)和先導(dao)控制(zhi)(zhi)兩種結構(gou)形式，直(zhi)接控制(zhi)(zhi)用的(de)(de)小流量小功率(lv)系(xi)統(tong)(tong)中，先導(dao)控制(zhi)(zhi) 用的(de)(de)大流量大功率(lv)系(xi)統(tong)(tong)中。 

這些年來國內(nei)在壓套機(ji)液(ye)(ye)(ye)(ye)壓件(jian)(jian)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)的(de)(de)研(yan)制和(he)(he)(he)(he)生產(chan)方(fang)面發展很(hen)快，但使用(yong)(yong)經驗(yan)表明，還存在一(yi)些需要進(jin)一(yi)步(bu)改進(jin)和(he)(he)(he)(he)完(wan)善(shan)的(de)(de)問(wen)(wen)題(ti)(ti)。首先是(shi)通用(yong)(yong)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)的(de)(de)適用(yong)(yong)性(xing)問(wen)(wen)題(ti)(ti)。對于(yu)(yu)一(yi)些結(jie)構復(fu)雜和(he)(he)(he)(he)具有內(nei)部油路的(de)(de)零(ling)部件(jian)(jian)，采(cai)用(yong)(yong)通用(yong)(yong)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)往(wang)往(wang)效(xiao)果不(bu)理想(xiang)，內(nei)部殘留(liu)的(de)(de)污(wu)(wu)染(ran)(ran)物(wu)很(hen)難沖洗(xi)(xi)(xi)出來，因而(er)應考(kao)慮(lv)選用(yong)(yong)或設(she)計(ji)專用(yong)(yong)的(de)(de)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)。其次(ci)是(shi)關于(yu)(yu)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)液(ye)(ye)(ye)(ye)的(de)(de)潔凈(jing)性(xing)問(wen)(wen)題(ti)(ti)。零(ling)件(jian)(jian)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)過(guo)程中(zhong)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)液(ye)(ye)(ye)(ye)應保持一(yi)定的(de)(de)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)度，這對于(yu)(yu)零(ling)件(jian)(jian)裝配前的(de)(de)精(jing)密清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)尤為重(zhong)要。目前國內(nei)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)較普遍(bian)地存在過(guo)濾(lv)(lv)(lv)裝置不(bu)夠完(wan)善(shan)的(de)(de)問(wen)(wen)題(ti)(ti)，過(guo)濾(lv)(lv)(lv)精(jing)度低，納垢容(rong)量小，不(bu)能(neng)(neng)有效(xiao)的(de)(de)濾(lv)(lv)(lv)除(chu)從(cong)零(ling)件(jian)(jian)沖洗(xi)(xi)(xi)出來的(de)(de)顆粒污(wu)(wu)染(ran)(ran)物(wu)。有的(de)(de)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)甚至沒有過(guo)濾(lv)(lv)(lv)設(she)備(bei)(bei)，而(er)是(shi)定期對清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)的(de)(de)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)液(ye)(ye)(ye)(ye)進(jin)行過(guo)濾(lv)(lv)(lv)凈(jing)化。這樣，在清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)的(de)(de)初期清(qing)(qing)(qing)(qing)(qing)(qing)潔度可能(neng)(neng)符(fu)合(he)要求，但清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)到(dao)后期，由于(yu)(yu)污(wu)(wu)染(ran)(ran)物(wu)積累(lei)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)液(ye)(ye)(ye)(ye)污(wu)(wu)染(ran)(ran)越來越嚴重(zhong)，不(bu)僅達不(bu)到(dao)清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)的(de)(de)目的(de)(de)，反而(er)污(wu)(wu)染(ran)(ran)了零(ling)件(jian)(jian)。因此，清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)設(she)備(bei)(bei)必須(xu)裝社具有足夠高的(de)(de)過(guo)濾(lv)(lv)(lv)精(jing)度和(he)(he)(he)(he)納垢容(rong)量的(de)(de)過(guo)濾(lv)(lv)(lv)器。采(cai)用(yong)(yong)可清(qing)(qing)(qing)(qing)(qing)(qing)洗(xi)(xi)(xi)濾(lv)(lv)(lv)芯和(he)(he)(he)(he)增加外過(guo)濾(lv)(lv)(lv)系(xi)統，可提高過(guo)濾(lv)(lv)(lv)凈(jing)化能(neng)(neng)力(li)并(bing)節約費用(yong)(yong)。