【正文】 空氣在油液中形成 氣泡，如果液壓支架在工作過程中在極短的時(shí)間內(nèi)，壓力在高低壓之間迅速變換就會(huì)使氣泡在高壓側(cè)產(chǎn)生高溫在低壓側(cè)發(fā)生爆裂，如果液壓系統(tǒng)的元件表面有凹點(diǎn)和損傷時(shí)，液壓油就會(huì)高速?zèng)_向元件表面加速表面的磨損，引起泄漏。如果在制造過程中超差，例如：油缸的活塞半徑、密封槽深度或?qū)挾取⒀b密封圈的孔尺寸超差或因加工問題而造成失圓、本身有毛刺或有洼點(diǎn)、鍍鉻脫落等，密封件就會(huì)有變形、劃傷、壓死或壓不實(shí)等現(xiàn)象發(fā)生使其失去密封功能。 二、影響泄漏的原因： （ 1）密封件的選擇 液壓系統(tǒng)的可靠性，在很大程度上取決于液壓系統(tǒng)密封的設(shè)計(jì)和密封件的選擇，由于設(shè)計(jì)中密封結(jié)構(gòu)選用不合理，密封件的選用不合乎規(guī)范，在設(shè)計(jì)中沒有考慮到液壓油與密封材料的相容型式、負(fù)載情況、極限壓力、工作速度大小、環(huán)境溫度的變化等。液壓系統(tǒng)一旦發(fā)生泄漏，將會(huì)引起系統(tǒng)壓力建立不起來，液壓油泄漏還會(huì)造成環(huán)境污染，影響生產(chǎn)甚至產(chǎn)生無法估計(jì)的嚴(yán)重后果。 然而，由于空氣的可壓縮性，使得氣壓系統(tǒng)執(zhí)行組件不可能得到精確的速度控制和位置控制。由丁氣壓系統(tǒng)直接向大氣排氣，會(huì)產(chǎn)生過大噪聲，因此可在氣閥和執(zhí)行組件排氣口安裝消聲器來降低噪聲，以防止操作人員因接觸噪聲及高速空氣粒子有可能引發(fā)的傷害。氣壓系統(tǒng)通?？紤]采用大的中央空氣壓縮機(jī)作為一個(gè)無限量的氣源，這類似于電力系統(tǒng)中只要將插頭插入插座便 可獲得電能。彈簧力使得葉片緊密地抵在內(nèi)壁上，以提高其工作效率。 液壓系統(tǒng)的其他優(yōu)點(diǎn)包 括雙向運(yùn)動(dòng)、過載保護(hù)和無級(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。這使得系統(tǒng)結(jié)構(gòu)緊湊，安全可靠。飛行員向相反方向移動(dòng)控制閥，允許 油液進(jìn)人液壓缸的另一腔來收同起落架。 企業(yè)為了提高生產(chǎn)率將越來越依靠自動(dòng)化，這包括遠(yuǎn)程和直接控制生產(chǎn)操作、加 1：過程和168。如壓力閥控制的是壓力，流量閥控制的是流量等 。 各類液壓控制閥雖然形式不同，控制的功能各有所異，但都 具有共性。油液貯存和調(diào)節(jié)裝置：用來確保提供足夠質(zhì)量和數(shù)量并冷卻的液體。介質(zhì)即油液：可進(jìn)行無壓縮傳遞和控制，同時(shí)可以潤滑部件，使閥體密封和系統(tǒng)冷卻。功率大小取決于對(duì)流量和壓力大小的控制。 液壓動(dòng)力傳遞系統(tǒng)涉及電動(dòng)機(jī)、調(diào)節(jié)裝置和壓力和流量控制，總的來說，該系統(tǒng)包括： 液壓與氣壓傳動(dòng)是研究以有壓流體為能源介質(zhì)，來實(shí)現(xiàn)各種機(jī)械的傳動(dòng)和自動(dòng)控制的學(xué)科．液壓傳動(dòng)與氣壓傳動(dòng)控制方法是基本相同的． 在流動(dòng)的液體中，因?yàn)橛幸欢康目諝?，一般溶?5%6%體積的 空氣，油液能溶解的空氣量與絕對(duì)壓力成正比，在大氣壓下正常溶解于油液中的空氣。大多數(shù)應(yīng)用系統(tǒng)實(shí)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)。 Air source similar to an electrical system where you merely plug into an electrical outlet for electricity． In this way， pressurized air can be piped from one source to various 10cations throughout an entire industrial plant． The pressed air car be Piped to each circuit through an air filter to remove contaminants which might harm the closely fitting parts of pneumatic ponents the such as valve and cylinders． The air then flows through a pressure regulator which reduces the pressure to the desired level for the particular circuit application． Because air is not a good 1ubricant(contains bout 20％ oxygen)，pneumatics systems required a lubricator to inject。 bearings， reduction gears， etc． are eliminated． This provides a simple， pact system． In addition， very little input torque is required to produce the control needed for the toughest applications． This is important where 1imitations of control space require a small steering wheel and it bees necessary to reduce operator fatigue． 設(shè)計(jì)巴巴工作室 There are several types of shaft couplings。 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 power transmission system ale concerned with the generation, modulation, and control of pressure and flow and ,and in general such systems include: 1． Pumps which convert available power from the prime mover to hydraulic power at the actuator． 2． Valves which control the direction of pumpflow， the level of power produced， and the amount of fluid 一一 flow to the actuators． The power level is determined by controlling both the flow and pressure level． 3． Actuators which convert hydraulic power to usable mechanical power Output at the point required． 4． The medium， which is a liquid， provides rigid transmission and control as well as 1ubrication of ponent s， sealing in valves． and cooling of the system． 5． Connectors which link the various system ponents， provide power conductors for the fluid under pressure， and fluid flow return to tank(reservoir)． ． Fluid storage and conditioning equipment which ensure sufficient quality and quantity as well as cooling of the fluid． pneumatics systems required a lubricator to inject。 their characteristics depend on the prupose for which they are used. If an exceptionally long shaft is required for a line shaft in the manufacturing plant or a propeller shaft on ship, it is made in sections that are coupled together with rigid couplings. Additional benefits of fluid power systems include instantly reversible motion。 a very fine mist of oil into the air discharging from the pressure regulator． This prevents wear of the closely fitting moving parts of pneumatic ponents． Free air from the atmosphere contains varying amounts of moisture． This moisture can be harmful in that it Can wash away lubricants and thus cause excessive wear and corros