軸承（Bearing）是(shi)當代(dai)機(ji)械(xie)設備中一種重要零部(bu)件。它的(de)主要功能是(shi)支撐機(ji)械(xie)旋轉體，降低(di)其(qi)運動過程中的(de)摩擦系(xi)數，并保證其(qi)回(hui)轉精度。

    按運動(dong)(dong)(dong)(dong)元件摩擦性質的不同，軸(zhou)承(cheng)可分為(wei)滾動(dong)(dong)(dong)(dong)軸(zhou)承(cheng)和滑(hua)(hua)動(dong)(dong)(dong)(dong)軸(zhou)承(cheng)兩大(da)類(lei)。其中滾動(dong)(dong)(dong)(dong)軸(zhou)承(cheng)已經標準化、系列化，但與滑(hua)(hua)動(dong)(dong)(dong)(dong)軸(zhou)承(cheng)相比(bi)它(ta)的徑(jing)向尺寸(cun)、振動(dong)(dong)(dong)(dong)和噪聲較大(da)，價格也較高。

    滾動軸承(cheng)一(yi)般由外圈、內圈、滾動體和保持架四部分組成。按(an)滾動體的(de)形(xing)狀，滾動軸承(cheng)分為球軸承(cheng)和滾子軸承(cheng)兩大類。

    早期的直線(xian)(xian)運動軸(zhou)承(cheng)(cheng)形式，就(jiu)(jiu)是(shi)(shi)在一排撬(qiao)板下放置一排木桿。現(xian)代(dai)(dai)直線(xian)(xian)運動軸(zhou)承(cheng)(cheng)使用(yong)的是(shi)(shi)同一種工(gong)作原(yuan)理(li)，只(zhi)不(bu)過有時用(yong)球代(dai)(dai)替(ti)滾(gun)子(zi)。最簡單(dan)的旋轉軸(zhou)承(cheng)(cheng)是(shi)(shi)軸(zhou)套軸(zhou)承(cheng)(cheng)，它只(zhi)是(shi)(shi)一個夾在車(che)(che)輪(lun)(lun)和輪(lun)(lun)軸(zhou)之間的襯套。這種設計隨后被滾(gun)動軸(zhou)承(cheng)(cheng)替(ti)代(dai)(dai)，就(jiu)(jiu)是(shi)(shi)用(yong)很多圓柱形的滾(gun)子(zi)替(ti)代(dai)(dai)原(yuan)先的襯套，每個滾(gun)動體就(jiu)(jiu)像一個單(dan)獨的車(che)(che)輪(lun)(lun)。

    調心滾子軸承有(you)兩列對稱型球面滾(gun)子，主要承(cheng)(cheng)受(shou)(shou)(shou)(shou)徑(jing)向(xiang)載荷(he)(he)，同(tong)(tong)(tong)時(shi)也能(neng)承(cheng)(cheng)受(shou)(shou)(shou)(shou)任一(yi)方向(xiang)的軸(zhou)(zhou)向(xiang)載荷(he)(he)，但不能(neng)承(cheng)(cheng)受(shou)(shou)(shou)(shou)純軸(zhou)(zhou)向(xiang)載荷(he)(he)。該類軸(zhou)(zhou)承(cheng)(cheng)外圈(quan)滾(gun)道(dao)是(shi)球面形，故其(qi)調(diao)心(xin)性能(neng)良好(hao)，能(neng)補償同(tong)(tong)(tong)軸(zhou)(zhou)度誤(wu)差(cha)，當(dang)軸(zhou)(zhou)受(shou)(shou)(shou)(shou)力(li)彎曲或安裝不同(tong)(tong)(tong)心(xin)時(shi)軸(zhou)(zhou)承(cheng)(cheng)仍可(ke)正常使用(yong)(yong)(yong)，調(diao)心(xin)性隨軸(zhou)(zhou)承(cheng)(cheng)尺寸系(xi)列不同(tong)(tong)(tong)而(er)異，一(yi)般所允許的調(diao)心(xin)角度為1~2.5度 ，該類型軸(zhou)(zhou)承(cheng)(cheng)的負荷(he)(he)能(neng)力(li)較大(da)，除(chu)能(neng)承(cheng)(cheng)受(shou)(shou)(shou)(shou)徑(jing)向(xiang)負荷(he)(he)外軸(zhou)(zhou)承(cheng)(cheng)還能(neng)承(cheng)(cheng)受(shou)(shou)(shou)(shou)雙向(xiang)作用(yong)(yong)(yong)的軸(zhou)(zhou)向(xiang)負荷(he)(he)，具有(you)較好(hao)的抗(kang)沖擊能(neng)力(li)，一(yi)般來說調(diao)心(xin)滾(gun)子軸(zhou)(zhou)承(cheng)(cheng)所允許的工(gong)作轉(zhuan)速較低。適用(yong)(yong)(yong)于重載或振動載荷(he)(he)下(xia)工(gong)作。