O形(xing)密(mi)(mi)封(feng)(feng)圈(quan)(quan)的(de)密(mi)(mi)封(feng)(feng)原(yuan)理O形(xing)密(mi)(mi)封(feng)(feng)圈(quan)(quan)簡稱(cheng)O形(xing)圈(quan)(quan)，是一種截面為(wei)圓形(xing)的(de)橡膠圈(quan)(quan)。O形(xing)密(mi)(mi)封(feng)(feng)圈(quan)(quan)是液(ye)壓、氣動體系(xi)中利(li)(li)用的(de)一種密(mi)(mi)封(feng)(feng)件。O形(xing)圈(quan)(quan)有(you)良好的(de)密(mi)(mi)封(feng)(feng)性，既可(ke)用于靜密(mi)(mi)封(feng)(feng)，也可(ke)用于往回生動密(mi)(mi)封(feng)(feng)中；不僅可(ke)單獨利(li)(li)用，而且是很(hen)多組(zu)合式密(mi)(mi)封(feng)(feng)裝置中的(de)基(ji)本組(zu)成局部。它的(de)實(shi)用范疇很(hen)寬，假(jia)如資料抉(jue)擇切當，可(ke)能(neng)滿意各(ge)種活動前提的(de)請求，工作壓力(li)可(ke)從1.333×105Pa的(de)真空到(dao)400MPa高壓；溫度范疇可(ke)從-60℃到(dao)200℃。

與其它密封(feng)(feng)型式比(bi)較，O形(xing)密封(feng)(feng)圈存(cun)在(zai)以(yi)下特(te)點： 1）結構尺寸小(xiao)(xiao)，裝拆便利。 2）靜(jing)、動密封(feng)(feng)均可(ke)利用(yong)，用(yong)作靜(jing)密封(feng)(feng)時多(duo)少乎不泄漏。 3）利用(yong)單(dan)件O形(xing)密封(feng)(feng)圈，有雙向密封(feng)(feng)作用(yong)。? ? ?4）動摩擦阻力(li)較小(xiao)(xiao)。5）價格低廉。

O形密(mi)(mi)(mi)封(feng)圈(quan)是一種擠壓(ya)(ya)型密(mi)(mi)(mi)封(feng)，擠壓(ya)(ya)型密(mi)(mi)(mi)封(feng)的基本工作原理是依(yi)附密(mi)(mi)(mi)封(feng)件產(chan)(chan)生彈性變形，在密(mi)(mi)(mi)封(feng)接(jie)(jie)觸(chu)(chu)面上造成(cheng)接(jie)(jie)觸(chu)(chu)壓(ya)(ya)力，接(jie)(jie)觸(chu)(chu)壓(ya)(ya)力大于(yu)被(bei)密(mi)(mi)(mi)封(feng)介質的內壓(ya)(ya)，則不產(chan)(chan)生泄(xie)漏，反(fan)之則產(chan)(chan)生泄(xie)漏。在用于(yu)靜密(mi)(mi)(mi)封(feng)跟動密(mi)(mi)(mi)封(feng)時，密(mi)(mi)(mi)封(feng)接(jie)(jie)觸(chu)(chu)面接(jie)(jie)觸(chu)(chu)壓(ya)(ya)力產(chan)(chan)生起因跟盤算方法(fa)不盡雷同，需分辨說明。

　　1、用(yong)(yong)于靜(jing)(jing)(jing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)時的(de)(de)(de)(de)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)原理? ? ? 在靜(jing)(jing)(jing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)中(zhong)以(yi)(yi)O形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)(quan)利用(yong)(yong)為(wei)(wei)普遍。假如設計、利用(yong)(yong)正確，O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)在靜(jing)(jing)(jing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)中(zhong)可能(neng)(neng)(neng)實(shi)現(xian)無泄(xie)漏的(de)(de)(de)(de)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)。? ? ? O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)裝入(ru)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)槽(cao)后(hou)(hou)，其(qi)截(jie)面蒙受接觸(chu)(chu)(chu)緊(jin)縮應力(li)(li)(li)(li)(li)而(er)產(chan)生(sheng)(sheng)彈性(xing)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)(xing)。對(dui)接觸(chu)(chu)(chu)面產(chan)生(sheng)(sheng)一(yi)定的(de)(de)(de)(de)初始(shi)接觸(chu)(chu)(chu)壓(ya)(ya)力(li)(li)(li)(li)(li)Po。即(ji)便不介(jie)(jie)質(zhi)壓(ya)(ya)力(li)(li)(li)(li)(li)或者(zhe)壓(ya)(ya)力(li)(li)(li)(li)(li)很小，O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)靠(kao)自(zi)身的(de)(de)(de)(de)彈性(xing)力(li)(li)(li)(li)(li)作(zuo)用(yong)(yong)而(er)也(ye)能(neng)(neng)(neng)實(shi)現(xian)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)；當容腔內(nei)充(chong)入(ru)有壓(ya)(ya)力(li)(li)(li)(li)(li)的(de)(de)(de)(de)介(jie)(jie)質(zhi)后(hou)(hou)，在介(jie)(jie)質(zhi)壓(ya)(ya)力(li)(li)(li)(li)(li)的(de)(de)(de)(de)作(zuo)用(yong)(yong)下，O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)產(chan)生(sheng)(sheng)位(wei)移，移向低(di)壓(ya)(ya)側，同時其(qi)彈性(xing)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)(xing)進一(yi)步加大(da)，填充(chong)跟封(feng)(feng)(feng)(feng)閉縫隙δ。此時，坐用(yong)(yong)于密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)副偶合(he)面的(de)(de)(de)(de)接觸(chu)(chu)(chu)壓(ya)(ya)力(li)(li)(li)(li)(li)回升(sheng)為(wei)(wei)Pm：? ? ?Pm=Po Pp? ? ?式中(zhong)Pp——經O形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)(quan)傳給接觸(chu)(chu)(chu)面的(de)(de)(de)(de)接觸(chu)(chu)(chu)壓(ya)(ya)力(li)(li)(li)(li)(li)（0.1MPa）? ? ?Pp=K〃P? ? ?K——壓(ya)(ya)力(li)(li)(li)(li)(li)傳遞系數(shu)，對(dui)橡膠制O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)K=1；? ? ?P——被密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)液體的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)(li)(li)（0.1MPa）。? ? ?從(cong)而(er)大(da)大(da)增加了密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)后(hou)(hou)果(guo)。因(yin)為(wei)(wei)個(ge)別(bie)K≥1，所以(yi)(yi)Pm＞P。由(you)此可見，只有O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)存在初始(shi)壓(ya)(ya)力(li)(li)(li)(li)(li)，就(jiu)能(neng)(neng)(neng)實(shi)現(xian)無泄(xie)漏的(de)(de)(de)(de)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)。這(zhe)種靠(kao)介(jie)(jie)質(zhi)自(zi)身壓(ya)(ya)力(li)(li)(li)(li)(li)來轉變(bian)(bian)O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)接觸(chu)(chu)(chu)狀(zhuang)況(kuang)，使之實(shi)現(xian)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)的(de)(de)(de)(de)性(xing)質(zhi)，稱為(wei)(wei)自(zi)封(feng)(feng)(feng)(feng)作(zuo)用(yong)(yong)。實(shi)際上(shang)(shang)，緊(jin)縮變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)(xing)即(ji)便為(wei)(wei)零，在油(you)壓(ya)(ya)力(li)(li)(li)(li)(li)下也(ye)能(neng)(neng)(neng)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)，但實(shi)際上(shang)(shang)O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)裝置時可能(neng)(neng)(neng)會有偏心。所以(yi)(yi)，O形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)(quan)裝入(ru)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)溝槽(cao)后(hou)(hou)，其(qi)斷(duan)面個(ge)別(bie)受到7%—30%的(de)(de)(de)(de)緊(jin)縮變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)(xing)。靜(jing)(jing)(jing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)取較大(da)的(de)(de)(de)(de)緊(jin)縮率值(zhi)，動密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)取較小的(de)(de)(de)(de)緊(jin)縮率值(zhi)。這(zhe)是因(yin)為(wei)(wei)合(he)成橡膠在低(di)溫(wen)(wen)下要緊(jin)縮，所以(yi)(yi)靜(jing)(jing)(jing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)O形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)(quan)的(de)(de)(de)(de)預(yu)緊(jin)縮量(liang)應考慮(lv)彌(mi)補它的(de)(de)(de)(de)低(di)溫(wen)(wen)緊(jin)縮量(liang)。

　　2、用(yong)(yong)于往(wang)(wang)回(hui)(hui)生動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)時(shi)的(de)(de)(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)原理? ? ? 在(zai)(zai)液(ye)壓轉動(dong)、氣動(dong)元件(jian)(jian)與(yu)體(ti)系中，往(wang)(wang)復動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)是(shi)一(yi)種常見的(de)(de)(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)請求。能(neng)源缸活(huo)(huo)塞與(yu)缸體(ti)、活(huo)(huo)塞干涉缸蓋以及(ji)各類(lei)滑(hua)(hua)閥上都用(yong)(yong)到往(wang)(wang)回(hui)(hui)生動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)。縫(feng)隙由圓(yuan)柱桿與(yu)圓(yuan)柱孔形(xing)成，桿在(zai)(zai)圓(yuan)柱孔內軸(zhou)(zhou)(zhou)向(xiang)活(huo)(huo)動(dong)。密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)作(zuo)用(yong)(yong)限度(du)流體(ti)的(de)(de)(de)(de)(de)軸(zhou)(zhou)(zhou)向(xiang)泄(xie)漏。用(yong)(yong)作(zuo)往(wang)(wang)回(hui)(hui)生動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)時(shi)，O形(xing)圈的(de)(de)(de)(de)(de)預密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)后果跟自(zi)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)作(zuo)用(yong)(yong)與(yu)靜密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)一(yi)樣，并(bing)且(qie)(qie)因為(wei)O形(xing)圈自(zi)身的(de)(de)(de)(de)(de)彈力(li)，而(er)存(cun)在(zai)(zai)磨損后主動(dong)彌補的(de)(de)(de)(de)(de)才干。但因為(wei)液(ye)體(ti)介質(zhi)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)時(shi)，因為(wei)桿活(huo)(huo)動(dong)速度(du)、液(ye)體(ti)的(de)(de)(de)(de)(de)壓力(li)、粘度(du)的(de)(de)(de)(de)(de)作(zuo)用(yong)(yong)，情況比靜密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)龐雜。? ? ? 當(dang)液(ye)體(ti)在(zai)(zai)壓力(li)作(zuo)用(yong)(yong)下(xia)，液(ye)體(ti)分子與(yu)金屬名義彼此作(zuo)用(yong)(yong)，油(you)液(ye)中所含的(de)(de)(de)(de)(de)“性分子”在(zai)(zai)金屬名義上周到而(er)整潔的(de)(de)(de)(de)(de)排(pai)列(lie)，沿滑(hua)(hua)移(yi)面(mian)與(yu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件(jian)(jian)間形(xing)成一(yi)個強固(gu)的(de)(de)(de)(de)(de)邊界層油(you)膜(mo)，并(bing)且(qie)(qie)對(dui)滑(hua)(hua)移(yi)面(mian)產生的(de)(de)(de)(de)(de)附著(zhu)力(li)。該液(ye)體(ti)薄膜(mo)始終存(cun)在(zai)(zai)于密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件(jian)(jian)與(yu)往(wang)(wang)回(hui)(hui)生動(dong)面(mian)之間，它(ta)亦起一(yi)定的(de)(de)(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)作(zuo)用(yong)(yong)，并(bing)且(qie)(qie)對(dui)活(huo)(huo)動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)面(mian)的(de)(de)(de)(de)(de)潤(run)滑(hua)(hua)是(shi)十分重要的(de)(de)(de)(de)(de)。然而(er)對(dui)泄(xie)漏來講(jiang)是(shi)有(you)害的(de)(de)(de)(de)(de)。但往(wang)(wang)回(hui)(hui)生動(dong)的(de)(de)(de)(de)(de)軸(zhou)(zhou)(zhou)向(xiang)外拖出時(shi)，軸(zhou)(zhou)(zhou)上的(de)(de)(de)(de)(de)液(ye)體(ti)薄膜(mo)便(bian)與(yu)軸(zhou)(zhou)(zhou)一(yi)起拉出，因為(wei)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件(jian)(jian)的(de)(de)(de)(de)(de)“擦拭”作(zuo)用(yong)(yong)，當(dang)往(wang)(wang)回(hui)(hui)生動(dong)的(de)(de)(de)(de)(de)軸(zhou)(zhou)(zhou)縮回(hui)(hui)時(shi)，該液(ye)體(ti)薄膜(mo)便(bian)被密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)元件(jian)(jian)阻留在(zai)(zai)外面(mian)。隨著(zhu)往(wang)(wang)回(hui)(hui)生動(dong)行程次數增(zeng)多，阻留在(zai)(zai)外面(mian)的(de)(de)(de)(de)(de)液(ye)體(ti)就越(yue)多，后形(xing)成油(you)滴(di)，這(zhe)就是(shi)往(wang)(wang)回(hui)(hui)生動(dong)式密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)裝置的(de)(de)(de)(de)(de)泄(xie)漏。因為(wei)液(ye)壓油(you)的(de)(de)(de)(de)(de)粘度(du)隨著(zhu)溫(wen)度(du)的(de)(de)(de)(de)(de)升高而(er)降落，油(you)膜(mo)厚(hou)度(du)相應減小，所以液(ye)壓設備在(zai)(zai)低溫(wen)下(xia)啟動(dong)時(shi)，活(huo)(huo)動(dong)開端時(shi)的(de)(de)(de)(de)(de)泄(xie)漏較(jiao)大，隨著(zhu)活(huo)(huo)動(dong)進程中因各種喪失引起溫(wen)度(du)升高，泄(xie)漏量有(you)逐步降落的(de)(de)(de)(de)(de)趨勢。

O形(xing)圈作(zuo)(zuo)為(wei)(wei)往(wang)(wang)復(fu)(fu)式(shi)密封，結構緊湊(cou)、尺寸小，可能降落元件(jian)價格(ge)。重要用(yong)(yong)在：? ? ? 1）低(di)壓(ya)液(ye)壓(ya)元件(jian)中(zhong)(zhong)(zhong)，個別限于(yu)短行程(cheng)跟10MPa左右(you)的(de)(de)中(zhong)(zhong)(zhong)等壓(ya)力(li)。? ? ? 2）小直(zhi)徑(jing)、短行程(cheng)以及中(zhong)(zhong)(zhong)等壓(ya)力(li)的(de)(de)液(ye)壓(ya)滑(hua)閥(fa)中(zhong)(zhong)(zhong)。? ? ? 3）氣(qi)動(dong)(dong)(dong)滑(hua)閥(fa)跟氣(qi)動(dong)(dong)(dong)缸中(zhong)(zhong)(zhong)。? ? ? 4）作(zuo)(zuo)為(wei)(wei)組合(he)式(shi)往(wang)(wang)復(fu)(fu)動(dong)(dong)(dong)密封裝(zhuang)(zhuang)置(zhi)中(zhong)(zhong)(zhong)的(de)(de)彈(dan)性(xing)體。? ? ?O形(xing)圈作(zuo)(zuo)為(wei)(wei)往(wang)(wang)復(fu)(fu)動(dong)(dong)(dong)密封適(shi)合(he)小直(zhi)徑(jing)、短行程(cheng)、中(zhong)(zhong)(zhong)低(di)壓(ya)力(li)的(de)(de)利(li)用(yong)(yong)處合(he)，氣(qi)動(dong)(dong)(dong)缸、氣(qi)動(dong)(dong)(dong)滑(hua)閥(fa)等往(wang)(wang)回(hui)生動(dong)(dong)(dong)元件(jian)中(zhong)(zhong)(zhong)。在液(ye)壓(ya)元件(jian)中(zhong)(zhong)(zhong)，用(yong)(yong)O形(xing)圈作(zuo)(zuo)重要動(dong)(dong)(dong)密封，個別限于(yu)短行程(cheng)跟10MPa左右(you)的(de)(de)中(zhong)(zhong)(zhong)低(di)壓(ya)力(li)。O形(xing)圈不合(he)實用(yong)(yong)作(zuo)(zuo)速度十(shi)分低(di)的(de)(de)往(wang)(wang)復(fu)(fu)動(dong)(dong)(dong)密封跟單獨作(zuo)(zuo)為(wei)(wei)高壓(ya)往(wang)(wang)復(fu)(fu)動(dong)(dong)(dong)密封。這(zhe)重要是因為(wei)(wei)在這(zhe)種前提下摩擦較大，會導(dao)致(zhi)密封過早生效(xiao)。在型式(shi)利(li)用(yong)(yong)中(zhong)(zhong)(zhong)，都(dou)要依據(ju)密封件(jian)的(de)(de)額定數據(ju)或才干(gan)來利(li)用(yong)(yong)，并且要裝(zhuang)(zhuang)配(pei)切(qie)當，才干(gan)得到滿(man)意的(de)(de)機能。

　　3、旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)活(huo)動用(yong)(yong)(yong)(yong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)? ? 在旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)活(huo)動密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)中(zhong)，通常采(cai)取油(you)(you)封(feng)(feng)(feng)(feng)跟機(ji)械密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)。然(ran)而油(you)(you)封(feng)(feng)(feng)(feng)的(de)(de)(de)利用(yong)(yong)(yong)(yong)壓(ya)力較低，而且與O形(xing)圈(quan)比較，顯得過(guo)大跟龐(pang)雜，工(gong)藝性也差。機(ji)械密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)誠然(ran)可用(yong)(yong)(yong)(yong)于(yu)高(gao)壓(ya)（40MPa）、高(gao)速(su)(su)（50m/s）及高(gao)溫(wen)（400℃），然(ran)而結構(gou)更加龐(pang)雜、宏大，而且本錢(qian)高(gao)，只實用(yong)(yong)(yong)(yong)于(yu)石油(you)(you)、化(hua)工(gong)等作(zuo)用(yong)(yong)(yong)(yong)的(de)(de)(de)一些(xie)(xie)(xie)重型機(ji)械設備(bei)上(shang)。? ? ?O形(xing)圈(quan)用(yong)(yong)(yong)(yong)于(yu)旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)活(huo)動存(cun)在的(de)(de)(de)重要問(wen)題是(shi)焦耳(er)熱(re)效應(ying)。焦耳(er)熱(re)效應(ying)使高(gao)速(su)(su)的(de)(de)(de)旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)軸與O形(xing)圈(quan)的(de)(de)(de)接觸(chu)處(chu)產生磨擦熱(re)，生成(cheng)的(de)(de)(de)熱(re)量使這(zhe)些(xie)(xie)(xie)接觸(chu)部位的(de)(de)(de)溫(wen)度一直回(hui)升，橡(xiang)膠(jiao)資(zi)料(liao)受熱(re)重大變形(xing)，緊(jin)(jin)(jin)縮(suo)量與伸(shen)長量產生變更的(de)(de)(de)景(jing)象。發(fa)熱(re)還(huan)加速(su)(su)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)資(zi)料(liao)老化(hua)，降(jiang)落了(le)? O形(xing)圈(quan)的(de)(de)(de)利用(yong)(yong)(yong)(yong)壽命；破壞(huai)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)油(you)(you)膜，由此(ci)引起斷(duan)(duan)油(you)(you)景(jing)象，加速(su)(su)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)的(de)(de)(de)磨損。? ? ?基于(yu)上(shang)述(shu)情況，近年來國(guo)內(nei)外旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)活(huo)動用(yong)(yong)(yong)(yong)O形(xing)圈(quan)進行了(le)普遍深刻的(de)(de)(de)研究。為了(le)避免呈現焦耳(er)熱(re)效應(ying)，要害在于(yu)依據橡(xiang)膠(jiao)的(de)(de)(de)機(ji)能來正確地抉擇設計(ji)(ji)O形(xing)圈(quan)的(de)(de)(de)結構(gou)參數，重要是(shi)O形(xing)圈(quan)的(de)(de)(de)拉伸(shen)量跟緊(jin)(jin)(jin)縮(suo)率。依據實驗，將(jiang)旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)活(huo)動用(yong)(yong)(yong)(yong)O形(xing)圈(quan)設計(ji)(ji)成(cheng)內(nei)徑(jing)與旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)軸直徑(jing)相等或稍(shao)大些(xie)(xie)(xie)，個別大3%~5%，在裝(zhuang)置O形(xing)圈(quan)時，從(cong)內(nei)徑(jing)向里緊(jin)(jin)(jin)縮(suo)，并將(jiang)斷(duan)(duan)面的(de)(de)(de)緊(jin)(jin)(jin)縮(suo)量也設計(ji)(ji)得小一些(xie)(xie)(xie)，個別約為5%。并且，盡量采(cai)取受熱(re)量影響小的(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)資(zi)料(liao)，充分考慮O形(xing)圈(quan)裝(zhuang)置處(chu)的(de)(de)(de)散(san)熱(re)問(wen)題。這(zhe)樣就(jiu)使O形(xing)圈(quan)的(de)(de)(de)工(gong)作(zuo)情況大為改(gai)良，可利用(yong)(yong)(yong)(yong)于(yu)轉(zhuan)(zhuan)(zhuan)速(su)(su)達4m/s的(de)(de)(de)旋(xuan)(xuan)轉(zhuan)(zhuan)(zhuan)軸的(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)。