;   軸承（Bearing）是當(dang)代機(ji)械(xie)(xie)設備中一種重要(yao)(yao)零(ling)部件。它(ta)的主要(yao)(yao)功能是支撐機(ji)械(xie)(xie)旋轉(zhuan)體，降低(di)其運(yun)動(dong)過程中的摩擦系數，并(bing)保(bao)證其回轉(zhuan)精(jing)度。

    按運動(dong)(dong)(dong)元(yuan)件摩擦性質(zhi)的不(bu)同(tong)，軸(zhou)承(cheng)可分為滾動(dong)(dong)(dong)軸(zhou)承(cheng)和滑動(dong)(dong)(dong)軸(zhou)承(cheng)兩(liang)大(da)(da)類(lei)。其中(zhong)滾動(dong)(dong)(dong)軸(zhou)承(cheng)已經(jing)標準化、系列(lie)化，但與滑動(dong)(dong)(dong)軸(zhou)承(cheng)相比它的徑(jing)向尺寸、振動(dong)(dong)(dong)和噪(zao)聲較(jiao)大(da)(da)，價格也(ye)較(jiao)高。

    滾動軸(zhou)承一般由外圈、內圈、滾動體(ti)(ti)和保持架四部(bu)分(fen)組(zu)成。按(an)滾動體(ti)(ti)的(de)形狀，滾動軸(zhou)承分(fen)為球軸(zhou)承和滾子軸(zhou)承兩大類。

    早期(qi)的(de)直線(xian)(xian)運動軸(zhou)承(cheng)(cheng)(cheng)形(xing)式，就(jiu)(jiu)是在(zai)一排(pai)撬板(ban)下放置一排(pai)木桿(gan)。現代直線(xian)(xian)運動軸(zhou)承(cheng)(cheng)(cheng)使用(yong)的(de)是同(tong)一種工作原理(li)，只(zhi)不過有時用(yong)球(qiu)代替(ti)滾子。最簡單的(de)旋轉軸(zhou)承(cheng)(cheng)(cheng)是軸(zhou)套(tao)(tao)軸(zhou)承(cheng)(cheng)(cheng)，它只(zhi)是一個(ge)(ge)夾在(zai)車輪和輪軸(zhou)之間的(de)襯(chen)套(tao)(tao)。這種設計隨后被滾動軸(zhou)承(cheng)(cheng)(cheng)替(ti)代，就(jiu)(jiu)是用(yong)很多圓柱形(xing)的(de)滾子替(ti)代原先的(de)襯(chen)套(tao)(tao)，每個(ge)(ge)滾動體就(jiu)(jiu)像一個(ge)(ge)單獨(du)的(de)車輪。

    調心滾子軸承有兩列對稱型球面滾(gun)子(zi)，主(zhu)要承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)(shou)徑向(xiang)載荷(he)(he)，同(tong)時也能(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)(shou)任(ren)一(yi)方向(xiang)的軸(zhou)(zhou)(zhou)向(xiang)載荷(he)(he)，但不(bu)能(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)(shou)純軸(zhou)(zhou)(zhou)向(xiang)載荷(he)(he)。該(gai)類(lei)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)外圈滾(gun)道是球面形，故其調心性能(neng)良好(hao)，能(neng)補償同(tong)軸(zhou)(zhou)(zhou)度(du)誤差，當軸(zhou)(zhou)(zhou)受(shou)(shou)(shou)(shou)力(li)彎曲(qu)或安裝不(bu)同(tong)心時軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)仍可正常(chang)使(shi)用(yong)，調心性隨軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)尺寸系列不(bu)同(tong)而異，一(yi)般所(suo)允許的調心角度(du)為1~2.5度(du) ，該(gai)類(lei)型軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)的負荷(he)(he)能(neng)力(li)較大，除能(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)(shou)徑向(xiang)負荷(he)(he)外軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)還(huan)能(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)(shou)雙(shuang)向(xiang)作用(yong)的軸(zhou)(zhou)(zhou)向(xiang)負荷(he)(he)，具有較好(hao)的抗沖擊能(neng)力(li)，一(yi)般來說調心滾(gun)子(zi)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)所(suo)允許的工作轉速較低。適用(yong)于(yu)重載或振動(dong)載荷(he)(he)下工作。