填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)改集(ji)式密(mi)封是指通過預緊或(huo)介質壓(ya)力(li)的自緊作(zuo)用(yong)(yong)使填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)與(yu)轉動件及固定件之間(jian)產生壓(ya)緊力(li)的動密(mi)封裝置(zhi)。又稱“填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)函密(mi)封”。結(jie)構(gou)形式較多(duo)，主要由填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)、填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)箱和填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)固定件組成(cheng)(cheng)。常用(yong)(yong)的填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)材料(liao)(liao)(liao)(liao)有(you)石(shi)棉(mian)織物、碳(tan)纖維、橡膠、柔性石(shi)墨和工程塑料(liao)(liao)(liao)(liao)等，預制成(cheng)(cheng)環狀或(huo)條(tiao)狀（有(you)的需預先浸漬(zi)潤滑性好的填(tian)(tian)(tian)(tian)(tian)充物），并采用(yong)(yong)多(duo)環或(huo)螺(luo)旋狀多(duo)層結(jie)構(gou)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)箱用(yong)(yong)以安置(zhi)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)固定件包括壓(ya)蓋、螺(luo)栓和彈簧(huang)等，用(yong)(yong)以使填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)預緊，工作(zuo)時阻止(zhi)介質外(wai)漏，彈簧(huang)可起補償(chang)作(zuo)用(yong)(yong)。

　　填(tian)(tian)料(liao)裝入填(tian)(tian)料(liao)腔以后，經壓蓋螺絲對(dui)它(ta)作軸(zhou)向壓縮，當(dang)軸(zhou)與填(tian)(tian)料(liao)有相對(dui)運動時，由(you)于(yu)填(tian)(tian)料(liao)的(de)(de)塑性，使它(ta)產生徑向力，并與軸(zhou)緊密接(jie)(jie)(jie)觸(chu)(chu)。與此同時，填(tian)(tian)料(liao)中(zhong)浸(jin)漬的(de)(de)潤滑(hua)劑(ji)被擠出，在接(jie)(jie)(jie)觸(chu)(chu)面之(zhi)(zhi)間形成(cheng)(cheng)油(you)膜。由(you)于(yu)接(jie)(jie)(jie)觸(chu)(chu)狀(zhuang)態并不(bu)是特(te)別(bie)均勻的(de)(de)，接(jie)(jie)(jie)觸(chu)(chu)部位(wei)(wei)便出現(xian)“邊界潤滑(hua)”狀(zhuang)態，稱為“軸(zhou)承效(xiao)(xiao)應”；而未接(jie)(jie)(jie)觸(chu)(chu)的(de)(de)凹部形成(cheng)(cheng)小油(you)槽，有較厚的(de)(de)油(you)膜，接(jie)(jie)(jie)觸(chu)(chu)部位(wei)(wei)與非(fei)接(jie)(jie)(jie)觸(chu)(chu)部位(wei)(wei)組(zu)成(cheng)(cheng)一(yi)道不(bu)規則(ze)的(de)(de)迷(mi)(mi)宮(gong)(gong)，起阻(zu)止液流泄漏的(de)(de)作用，此稱“迷(mi)(mi)宮(gong)(gong)效(xiao)(xiao)應”。這就是填(tian)(tian)料(liao)密封的(de)(de)機理。顯然(ran)，良(liang)(liang)好(hao)的(de)(de)密封在于(yu)維持“軸(zhou)承效(xiao)(xiao)應”和“迷(mi)(mi)宮(gong)(gong)效(xiao)(xiao)應”。也就是說，要保持良(liang)(liang)好(hao)的(de)(de)潤滑(hua)和適當(dang)的(de)(de)壓緊。若潤滑(hua)不(bu)良(liang)(liang)，或壓得過緊都會使油(you)膜中(zhong)斷，造成(cheng)(cheng)填(tian)(tian)料(liao)與軸(zhou)之(zhi)(zhi)間出現(xian)干摩擦，最(zui)后導致(zhi)燒軸(zhou)和出現(xian)嚴重(zhong)磨損(sun)。

　　為此，需要經(jing)常對填(tian)(tian)料(liao)的(de)壓(ya)緊(jin)程度進(jin)行調整，以便填(tian)(tian)料(liao)中的(de)潤滑劑(ji)在運行一(yi)段時間流失之后，再擠出一(yi)些(xie)潤滑劑(ji)，同時補(bu)償填(tian)(tian)料(liao)因(yin)體積變化所造成的(de)壓(ya)緊(jin)力松弛(chi)。顯然，這樣經(jing)常擠壓(ya)填(tian)(tian)料(liao)，最終(zhong)將使浸漬劑(ji)枯竭(jie)，所以定期更換(huan)填(tian)(tian)料(liao)是必要的(de)。此外(wai)，為了(le)維持液(ye)膜(mo)和帶走摩擦熱，有意讓填(tian)(tian)料(liao)處有少量泄漏也(ye)是必要的(de)。