填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)改集式密封是指通(tong)過(guo)預緊(jin)或介(jie)質壓力的(de)自(zi)緊(jin)作(zuo)用(yong)(yong)使填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)與轉動(dong)件(jian)(jian)及固定件(jian)(jian)之(zhi)間產生壓緊(jin)力的(de)動(dong)密封裝置。又稱(cheng)“填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)函密封”。結構形式較多，主要由填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)、填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)箱(xiang)(xiang)和填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)固定件(jian)(jian)組成。常用(yong)(yong)的(de)填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)材(cai)料(liao)(liao)有石(shi)棉織(zhi)物、碳(tan)纖維、橡膠(jiao)、柔性石(shi)墨和工(gong)程塑料(liao)(liao)等(deng)，預制成環狀(zhuang)或條狀(zhuang)（有的(de)需預先浸漬潤滑性好的(de)填(tian)(tian)(tian)(tian)(tian)(tian)充物），并采用(yong)(yong)多環或螺(luo)旋(xuan)狀(zhuang)多層結構。填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)箱(xiang)(xiang)用(yong)(yong)以(yi)安(an)置填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)。填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)固定件(jian)(jian)包括壓蓋、螺(luo)栓和彈(dan)簧(huang)等(deng)，用(yong)(yong)以(yi)使填(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)預緊(jin)，工(gong)作(zuo)時阻止介(jie)質外漏(lou)，彈(dan)簧(huang)可起補償作(zuo)用(yong)(yong)。

　　填(tian)(tian)(tian)料(liao)裝(zhuang)入填(tian)(tian)(tian)料(liao)腔以后，經壓(ya)(ya)蓋螺絲對它(ta)作軸(zhou)向壓(ya)(ya)縮，當軸(zhou)與填(tian)(tian)(tian)料(liao)有(you)(you)相對運動時，由于(yu)填(tian)(tian)(tian)料(liao)的塑性，使它(ta)產生徑向力，并與軸(zhou)緊(jin)密(mi)接(jie)(jie)觸。與此同時，填(tian)(tian)(tian)料(liao)中浸漬的潤滑(hua)劑被擠(ji)出，在接(jie)(jie)觸面之間(jian)形(xing)(xing)成(cheng)油(you)膜。由于(yu)接(jie)(jie)觸狀態(tai)并不(bu)(bu)是(shi)(shi)特別均勻的，接(jie)(jie)觸部(bu)(bu)位便出現(xian)(xian)“邊界潤滑(hua)”狀態(tai)，稱(cheng)為(wei)“軸(zhou)承效應”；而未接(jie)(jie)觸的凹(ao)部(bu)(bu)形(xing)(xing)成(cheng)小油(you)槽，有(you)(you)較厚(hou)的油(you)膜，接(jie)(jie)觸部(bu)(bu)位與非(fei)接(jie)(jie)觸部(bu)(bu)位組成(cheng)一(yi)道不(bu)(bu)規則的迷宮(gong)，起阻(zu)止液流(liu)泄漏的作用，此稱(cheng)“迷宮(gong)效應”。這(zhe)就是(shi)(shi)填(tian)(tian)(tian)料(liao)密(mi)封的機理。顯然(ran)，良(liang)好的密(mi)封在于(yu)維持(chi)“軸(zhou)承效應”和(he)“迷宮(gong)效應”。也就是(shi)(shi)說(shuo)，要保持(chi)良(liang)好的潤滑(hua)和(he)適當的壓(ya)(ya)緊(jin)。若潤滑(hua)不(bu)(bu)良(liang)，或壓(ya)(ya)得過緊(jin)都會使油(you)膜中斷(duan)，造成(cheng)填(tian)(tian)(tian)料(liao)與軸(zhou)之間(jian)出現(xian)(xian)干摩擦，最后導致燒軸(zhou)和(he)出現(xian)(xian)嚴重磨損(sun)。

　　為此，需要經常對填料(liao)的(de)(de)壓緊程度進行(xing)調整，以便填料(liao)中的(de)(de)潤滑劑在運(yun)行(xing)一(yi)(yi)段時(shi)間流失之后(hou)，再擠(ji)出一(yi)(yi)些潤滑劑，同時(shi)補償填料(liao)因(yin)體(ti)積變化(hua)所造成的(de)(de)壓緊力松弛。顯然，這樣經常擠(ji)壓填料(liao)，最終(zhong)將(jiang)使浸漬劑枯竭，所以定期(qi)更換填料(liao)是(shi)(shi)必(bi)(bi)要的(de)(de)。此外，為了維持液(ye)膜和帶走摩擦熱，有意讓填料(liao)處(chu)有少量泄漏(lou)也是(shi)(shi)必(bi)(bi)要的(de)(de)。