填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)改集式密封是指通過預緊(jin)(jin)或(huo)介質壓力的自緊(jin)(jin)作用(yong)(yong)(yong)使(shi)填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)與轉動(dong)件(jian)及固(gu)定件(jian)之間產生壓緊(jin)(jin)力的動(dong)密封裝置(zhi)。又稱“填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)函(han)密封”。結(jie)構形式較多(duo)，主要由填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)、填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)箱(xiang)和(he)填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)固(gu)定件(jian)組(zu)成。常用(yong)(yong)(yong)的填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)材(cai)料(liao)(liao)(liao)(liao)(liao)有石棉(mian)織(zhi)物、碳纖維、橡(xiang)膠、柔性石墨(mo)和(he)工(gong)程塑料(liao)(liao)(liao)(liao)(liao)等(deng)，預制成環狀(zhuang)或(huo)條狀(zhuang)（有的需預先(xian)浸漬潤滑(hua)性好的填(tian)(tian)充物），并采用(yong)(yong)(yong)多(duo)環或(huo)螺(luo)旋(xuan)狀(zhuang)多(duo)層結(jie)構。填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)箱(xiang)用(yong)(yong)(yong)以安置(zhi)填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)。填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)固(gu)定件(jian)包括壓蓋(gai)、螺(luo)栓和(he)彈簧(huang)等(deng)，用(yong)(yong)(yong)以使(shi)填(tian)(tian)料(liao)(liao)(liao)(liao)(liao)預緊(jin)(jin)，工(gong)作時阻(zu)止介質外漏，彈簧(huang)可(ke)起補償作用(yong)(yong)(yong)。

　　填料(liao)(liao)裝(zhuang)入(ru)填料(liao)(liao)腔以后，經壓(ya)(ya)蓋螺絲對(dui)它作(zuo)軸(zhou)(zhou)向壓(ya)(ya)縮(suo)，當(dang)軸(zhou)(zhou)與(yu)(yu)填料(liao)(liao)有相對(dui)運(yun)動時(shi)，由于(yu)填料(liao)(liao)的塑(su)性(xing)，使它產生徑向力，并與(yu)(yu)軸(zhou)(zhou)緊(jin)密接(jie)(jie)(jie)觸。與(yu)(yu)此同(tong)時(shi)，填料(liao)(liao)中(zhong)浸漬的潤(run)(run)滑(hua)劑(ji)被(bei)擠出(chu)，在接(jie)(jie)(jie)觸面之間形(xing)成(cheng)油(you)膜(mo)(mo)。由于(yu)接(jie)(jie)(jie)觸狀態并不(bu)是特(te)別均(jun)勻的，接(jie)(jie)(jie)觸部(bu)(bu)位(wei)便出(chu)現(xian)(xian)“邊界潤(run)(run)滑(hua)”狀態，稱(cheng)(cheng)為“軸(zhou)(zhou)承效應(ying)(ying)”；而未接(jie)(jie)(jie)觸的凹部(bu)(bu)形(xing)成(cheng)小油(you)槽，有較厚的油(you)膜(mo)(mo)，接(jie)(jie)(jie)觸部(bu)(bu)位(wei)與(yu)(yu)非接(jie)(jie)(jie)觸部(bu)(bu)位(wei)組成(cheng)一道(dao)不(bu)規則的迷宮(gong)，起阻止液流泄漏的作(zuo)用，此稱(cheng)(cheng)“迷宮(gong)效應(ying)(ying)”。這就是填料(liao)(liao)密封的機理。顯然，良好的密封在于(yu)維(wei)持(chi)“軸(zhou)(zhou)承效應(ying)(ying)”和“迷宮(gong)效應(ying)(ying)”。也就是說，要(yao)保持(chi)良好的潤(run)(run)滑(hua)和適當(dang)的壓(ya)(ya)緊(jin)。若(ruo)潤(run)(run)滑(hua)不(bu)良，或(huo)壓(ya)(ya)得過緊(jin)都(dou)會使油(you)膜(mo)(mo)中(zhong)斷(duan)，造成(cheng)填料(liao)(liao)與(yu)(yu)軸(zhou)(zhou)之間出(chu)現(xian)(xian)干(gan)摩擦，最后導致燒軸(zhou)(zhou)和出(chu)現(xian)(xian)嚴重磨(mo)損。

　　為此(ci)，需要經常(chang)對填(tian)料(liao)(liao)的壓緊程度進行調整，以便填(tian)料(liao)(liao)中(zhong)的潤滑劑在運(yun)行一段時(shi)間流失之后，再擠出一些潤滑劑，同時(shi)補償(chang)填(tian)料(liao)(liao)因體積變化所造(zao)成的壓緊力松弛。顯然，這樣經常(chang)擠壓填(tian)料(liao)(liao)，最(zui)終將使浸(jin)漬劑枯竭，所以定(ding)期更換(huan)填(tian)料(liao)(liao)是必要的。此(ci)外，為了維持液膜(mo)和帶走摩擦熱，有意(yi)讓填(tian)料(liao)(liao)處有少量泄漏也(ye)是必要的。