軸承（Bearing）是(shi)當代機械設備中(zhong)一種重要(yao)零部件。它的主(zhu)要(yao)功能是(shi)支撐機械旋轉體，降低其運動過程中(zhong)的摩(mo)擦系數(shu)，并保證其回轉精度。

    按運動(dong)(dong)(dong)元件摩擦性質(zhi)的不(bu)同，軸承(cheng)可分為滾動(dong)(dong)(dong)軸承(cheng)和滑動(dong)(dong)(dong)軸承(cheng)兩大類。其中滾動(dong)(dong)(dong)軸承(cheng)已經標(biao)準化(hua)、系列(lie)化(hua)，但與滑動(dong)(dong)(dong)軸承(cheng)相比它的徑向尺寸、振動(dong)(dong)(dong)和噪聲較大，價格也較高。

    滾(gun)(gun)動軸(zhou)承(cheng)(cheng)一般由(you)外圈、內圈、滾(gun)(gun)動體和保(bao)持架(jia)四部分組成。按滾(gun)(gun)動體的形狀，滾(gun)(gun)動軸(zhou)承(cheng)(cheng)分為球軸(zhou)承(cheng)(cheng)和滾(gun)(gun)子(zi)軸(zhou)承(cheng)(cheng)兩大類(lei)。

    早期的直(zhi)線運動軸(zhou)承(cheng)形(xing)式，就(jiu)是(shi)(shi)在(zai)一(yi)排撬板(ban)下放(fang)置一(yi)排木桿。現代直(zhi)線運動軸(zhou)承(cheng)使(shi)用(yong)的是(shi)(shi)同一(yi)種工作(zuo)原(yuan)理，只(zhi)不過有(you)時用(yong)球(qiu)代替滾(gun)子。最簡(jian)單的旋(xuan)轉軸(zhou)承(cheng)是(shi)(shi)軸(zhou)套(tao)軸(zhou)承(cheng)，它只(zhi)是(shi)(shi)一(yi)個(ge)(ge)夾(jia)在(zai)車輪(lun)和(he)輪(lun)軸(zhou)之間(jian)的襯套(tao)。這(zhe)種設(she)計隨后被(bei)滾(gun)動軸(zhou)承(cheng)替代，就(jiu)是(shi)(shi)用(yong)很多圓柱(zhu)形(xing)的滾(gun)子替代原(yuan)先的襯套(tao)，每個(ge)(ge)滾(gun)動體就(jiu)像一(yi)個(ge)(ge)單獨的車輪(lun)。

    調心滾子軸承有(you)兩(liang)列對稱型球面滾(gun)(gun)子(zi)(zi)，主(zhu)要承(cheng)(cheng)受(shou)(shou)(shou)徑(jing)向(xiang)(xiang)(xiang)載(zai)荷(he)(he)(he)，同時也能(neng)(neng)(neng)承(cheng)(cheng)受(shou)(shou)(shou)任(ren)一方向(xiang)(xiang)(xiang)的軸(zhou)向(xiang)(xiang)(xiang)載(zai)荷(he)(he)(he)，但不(bu)能(neng)(neng)(neng)承(cheng)(cheng)受(shou)(shou)(shou)純軸(zhou)向(xiang)(xiang)(xiang)載(zai)荷(he)(he)(he)。該類(lei)軸(zhou)承(cheng)(cheng)外圈滾(gun)(gun)道是球面形，故(gu)其調(diao)心(xin)(xin)(xin)性能(neng)(neng)(neng)良好，能(neng)(neng)(neng)補(bu)償同軸(zhou)度誤差，當軸(zhou)受(shou)(shou)(shou)力彎曲或安裝不(bu)同心(xin)(xin)(xin)時軸(zhou)承(cheng)(cheng)仍(reng)可正常使(shi)用(yong)(yong)，調(diao)心(xin)(xin)(xin)性隨軸(zhou)承(cheng)(cheng)尺寸系(xi)列不(bu)同而異，一般所(suo)允許的調(diao)心(xin)(xin)(xin)角度為1~2.5度 ，該類(lei)型軸(zhou)承(cheng)(cheng)的負(fu)荷(he)(he)(he)能(neng)(neng)(neng)力較大，除(chu)能(neng)(neng)(neng)承(cheng)(cheng)受(shou)(shou)(shou)徑(jing)向(xiang)(xiang)(xiang)負(fu)荷(he)(he)(he)外軸(zhou)承(cheng)(cheng)還能(neng)(neng)(neng)承(cheng)(cheng)受(shou)(shou)(shou)雙向(xiang)(xiang)(xiang)作用(yong)(yong)的軸(zhou)向(xiang)(xiang)(xiang)負(fu)荷(he)(he)(he)，具(ju)有(you)較好的抗沖(chong)擊能(neng)(neng)(neng)力，一般來說調(diao)心(xin)(xin)(xin)滾(gun)(gun)子(zi)(zi)軸(zhou)承(cheng)(cheng)所(suo)允許的工(gong)作轉速較低(di)。適(shi)用(yong)(yong)于重載(zai)或振(zhen)動載(zai)荷(he)(he)(he)下工(gong)作。