填(tian)(tian)(tian)(tian)料(liao)改集(ji)式密(mi)封是指通過預(yu)緊或(huo)(huo)介質壓(ya)(ya)力(li)的(de)自(zi)緊作(zuo)用(yong)(yong)使(shi)填(tian)(tian)(tian)(tian)料(liao)與轉動(dong)件(jian)及固定(ding)件(jian)之(zhi)間產生壓(ya)(ya)緊力(li)的(de)動(dong)密(mi)封裝置。又(you)稱(cheng)“填(tian)(tian)(tian)(tian)料(liao)函密(mi)封”。結(jie)構形式較多(duo)，主要由填(tian)(tian)(tian)(tian)料(liao)、填(tian)(tian)(tian)(tian)料(liao)箱(xiang)和填(tian)(tian)(tian)(tian)料(liao)固定(ding)件(jian)組成(cheng)。常用(yong)(yong)的(de)填(tian)(tian)(tian)(tian)料(liao)材料(liao)有(you)石(shi)棉織物(wu)、碳纖維、橡膠、柔性石(shi)墨(mo)和工(gong)(gong)程塑料(liao)等，預(yu)制成(cheng)環狀(zhuang)或(huo)(huo)條狀(zhuang)（有(you)的(de)需預(yu)先(xian)浸漬潤滑性好的(de)填(tian)(tian)(tian)(tian)充物(wu)），并采用(yong)(yong)多(duo)環或(huo)(huo)螺旋狀(zhuang)多(duo)層結(jie)構。填(tian)(tian)(tian)(tian)料(liao)箱(xiang)用(yong)(yong)以安置填(tian)(tian)(tian)(tian)料(liao)。填(tian)(tian)(tian)(tian)料(liao)固定(ding)件(jian)包括(kuo)壓(ya)(ya)蓋、螺栓和彈(dan)簧等，用(yong)(yong)以使(shi)填(tian)(tian)(tian)(tian)料(liao)預(yu)緊，工(gong)(gong)作(zuo)時阻止介質外漏(lou)，彈(dan)簧可起補償作(zuo)用(yong)(yong)。

　　填(tian)(tian)料(liao)(liao)(liao)裝入(ru)填(tian)(tian)料(liao)(liao)(liao)腔以(yi)后，經壓(ya)(ya)蓋(gai)螺絲對(dui)它作(zuo)軸(zhou)(zhou)向(xiang)壓(ya)(ya)縮，當(dang)軸(zhou)(zhou)與(yu)填(tian)(tian)料(liao)(liao)(liao)有相對(dui)運(yun)動時，由(you)于(yu)填(tian)(tian)料(liao)(liao)(liao)的(de)(de)(de)(de)塑(su)性，使它產(chan)生(sheng)徑向(xiang)力，并與(yu)軸(zhou)(zhou)緊(jin)密(mi)(mi)接(jie)觸(chu)。與(yu)此同時，填(tian)(tian)料(liao)(liao)(liao)中(zhong)浸漬的(de)(de)(de)(de)潤滑(hua)劑被擠出(chu)(chu)，在(zai)(zai)接(jie)觸(chu)面之間(jian)(jian)形成(cheng)(cheng)油(you)(you)膜(mo)。由(you)于(yu)接(jie)觸(chu)狀(zhuang)態(tai)并不是特別均(jun)勻的(de)(de)(de)(de)，接(jie)觸(chu)部位(wei)便出(chu)(chu)現(xian)“邊界(jie)潤滑(hua)”狀(zhuang)態(tai)，稱為“軸(zhou)(zhou)承(cheng)(cheng)效(xiao)應(ying)”；而未(wei)接(jie)觸(chu)的(de)(de)(de)(de)凹部形成(cheng)(cheng)小油(you)(you)槽，有較厚的(de)(de)(de)(de)油(you)(you)膜(mo)，接(jie)觸(chu)部位(wei)與(yu)非接(jie)觸(chu)部位(wei)組成(cheng)(cheng)一道不規則(ze)的(de)(de)(de)(de)迷宮，起(qi)阻止液流(liu)泄漏的(de)(de)(de)(de)作(zuo)用，此稱“迷宮效(xiao)應(ying)”。這就是填(tian)(tian)料(liao)(liao)(liao)密(mi)(mi)封的(de)(de)(de)(de)機(ji)理。顯然，良(liang)好的(de)(de)(de)(de)密(mi)(mi)封在(zai)(zai)于(yu)維(wei)持(chi)“軸(zhou)(zhou)承(cheng)(cheng)效(xiao)應(ying)”和(he)(he)“迷宮效(xiao)應(ying)”。也就是說，要保持(chi)良(liang)好的(de)(de)(de)(de)潤滑(hua)和(he)(he)適當(dang)的(de)(de)(de)(de)壓(ya)(ya)緊(jin)。若潤滑(hua)不良(liang)，或壓(ya)(ya)得過緊(jin)都會使油(you)(you)膜(mo)中(zhong)斷，造成(cheng)(cheng)填(tian)(tian)料(liao)(liao)(liao)與(yu)軸(zhou)(zhou)之間(jian)(jian)出(chu)(chu)現(xian)干(gan)摩擦，最后導致燒軸(zhou)(zhou)和(he)(he)出(chu)(chu)現(xian)嚴重磨(mo)損。

　　為(wei)此，需要經(jing)常(chang)對(dui)填(tian)料的(de)(de)(de)壓(ya)(ya)(ya)緊程(cheng)度進行(xing)(xing)調整(zheng)，以便填(tian)料中的(de)(de)(de)潤滑劑(ji)在運行(xing)(xing)一段時(shi)間流失之后，再擠(ji)(ji)出一些潤滑劑(ji)，同時(shi)補償填(tian)料因(yin)體積(ji)變化所(suo)造(zao)成的(de)(de)(de)壓(ya)(ya)(ya)緊力松(song)弛。顯然，這樣經(jing)常(chang)擠(ji)(ji)壓(ya)(ya)(ya)填(tian)料，最(zui)終將使(shi)浸漬劑(ji)枯竭，所(suo)以定期更換填(tian)料是必要的(de)(de)(de)。此外，為(wei)了維持液膜和帶走摩(mo)擦(ca)熱，有意讓填(tian)料處有少量泄漏(lou)也(ye)是必要的(de)(de)(de)。