;   軸(zhou)承（Bearing）是(shi)(shi)當(dang)代機械(xie)設備中(zhong)一種重要零部件。它的主要功能是(shi)(shi)支撐機械(xie)旋轉(zhuan)體，降低其運動過程中(zhong)的摩(mo)擦系數，并保證其回轉(zhuan)精度(du)。

    按(an)運動(dong)元件摩擦性質(zhi)的不同，軸承(cheng)可分為滾(gun)動(dong)軸承(cheng)和滑(hua)動(dong)軸承(cheng)兩大(da)類。其(qi)中滾(gun)動(dong)軸承(cheng)已經標(biao)準(zhun)化、系列化，但與滑(hua)動(dong)軸承(cheng)相比它的徑(jing)向尺寸、振動(dong)和噪聲(sheng)較大(da)，價格也較高。

    滾(gun)動(dong)(dong)軸承(cheng)一般由(you)外圈、內圈、滾(gun)動(dong)(dong)體和保持(chi)架四部分組成。按滾(gun)動(dong)(dong)體的形狀，滾(gun)動(dong)(dong)軸承(cheng)分為球軸承(cheng)和滾(gun)子軸承(cheng)兩大類。

    早期的(de)(de)直線運動(dong)軸(zhou)(zhou)承(cheng)形式，就是在一(yi)排撬板(ban)下放置一(yi)排木桿(gan)。現代直線運動(dong)軸(zhou)(zhou)承(cheng)使用(yong)(yong)的(de)(de)是同一(yi)種工作原(yuan)理，只(zhi)不過有(you)時用(yong)(yong)球代替(ti)滾(gun)子。最簡單的(de)(de)旋轉(zhuan)軸(zhou)(zhou)承(cheng)是軸(zhou)(zhou)套(tao)軸(zhou)(zhou)承(cheng)，它(ta)只(zhi)是一(yi)個夾在車輪(lun)和輪(lun)軸(zhou)(zhou)之(zhi)間的(de)(de)襯(chen)套(tao)。這(zhe)種設計(ji)隨后(hou)被滾(gun)動(dong)軸(zhou)(zhou)承(cheng)替(ti)代，就是用(yong)(yong)很多(duo)圓柱形的(de)(de)滾(gun)子替(ti)代原(yuan)先的(de)(de)襯(chen)套(tao)，每(mei)個滾(gun)動(dong)體就像一(yi)個單獨的(de)(de)車輪(lun)。

    調心滾子軸承有兩列對稱型球面滾(gun)子，主要承(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)徑(jing)向(xiang)(xiang)載(zai)(zai)荷，同(tong)時也(ye)能(neng)(neng)(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)任(ren)一(yi)方向(xiang)(xiang)的軸(zhou)(zhou)向(xiang)(xiang)載(zai)(zai)荷，但不能(neng)(neng)(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)純軸(zhou)(zhou)向(xiang)(xiang)載(zai)(zai)荷。該類軸(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)外(wai)(wai)圈滾(gun)道是球面形，故其調(diao)(diao)心(xin)(xin)性(xing)能(neng)(neng)(neng)良好(hao)，能(neng)(neng)(neng)補償同(tong)軸(zhou)(zhou)度誤(wu)差，當軸(zhou)(zhou)受(shou)(shou)(shou)力(li)彎曲(qu)或安裝不同(tong)心(xin)(xin)時軸(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)仍可正常使用(yong)，調(diao)(diao)心(xin)(xin)性(xing)隨軸(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)尺寸(cun)系列不同(tong)而異(yi)，一(yi)般(ban)(ban)所(suo)允(yun)許的調(diao)(diao)心(xin)(xin)角度為1~2.5度 ，該類型軸(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)的負荷能(neng)(neng)(neng)力(li)較大，除能(neng)(neng)(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)徑(jing)向(xiang)(xiang)負荷外(wai)(wai)軸(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)還能(neng)(neng)(neng)承(cheng)(cheng)(cheng)(cheng)(cheng)受(shou)(shou)(shou)雙向(xiang)(xiang)作用(yong)的軸(zhou)(zhou)向(xiang)(xiang)負荷，具有較好(hao)的抗沖(chong)擊能(neng)(neng)(neng)力(li)，一(yi)般(ban)(ban)來(lai)說(shuo)調(diao)(diao)心(xin)(xin)滾(gun)子軸(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)所(suo)允(yun)許的工(gong)作轉速較低(di)。適用(yong)于重(zhong)載(zai)(zai)或振動載(zai)(zai)荷下(xia)工(gong)作。