直(zhi)線(xian)導軌又稱線(xian)軌、滑軌、線(xian)性導軌、線(xian)性滑軌，用于高(gao)精或(huo)高(gao)速直(zhi)線(xian)往復(fu)運動場合，且可以承擔一(yi)定的(de)(de)扭矩，可在高(gao)負載的(de)(de)情況(kuang)下實(shi)現高(gao)精度的(de)(de)直(zhi)線(xian)運動。

直(zhi)線(xian)導(dao)(dao)(dao)軌(gui)運(yun)(yun)動(dong)(dong)(dong)的(de)(de)(de)作(zuo)用是(shi)(shi)(shi)用來支撐和引導(dao)(dao)(dao)運(yun)(yun)動(dong)(dong)(dong)部(bu)件，按給定(ding)的(de)(de)(de)方向做往(wang)復直(zhi)線(xian)運(yun)(yun)動(dong)(dong)(dong)。　直(zhi)線(xian)軸承(cheng)主要用在自(zi)動(dong)(dong)(dong)化(hua)機(ji)械(xie)上比較(jiao)多(duo),像直(zhi)線(xian)導(dao)(dao)(dao)軌(gui)主要是(shi)(shi)(shi)用在精(jing)度(du)(du)要求比較(jiao)高的(de)(de)(de)機(ji)械(xie)結(jie)構上,直(zhi)線(xian)導(dao)(dao)(dao)軌(gui)的(de)(de)(de)移動(dong)(dong)(dong)元件和固定(ding)元件之(zhi)間(jian)(jian)不用中間(jian)(jian)介質，而(er)用滾(gun)(gun)動(dong)(dong)(dong)鋼球。可以理(li)解為(wei)是(shi)(shi)(shi)一種(zhong)滾(gun)(gun)動(dong)(dong)(dong)導(dao)(dao)(dao)引，是(shi)(shi)(shi)由鋼珠在滑(hua)塊跟導(dao)(dao)(dao)軌(gui)之(zhi)間(jian)(jian)無限滾(gun)(gun)動(dong)(dong)(dong)循環， 從而(er)使負載平(ping)臺沿(yan)著導(dao)(dao)(dao)軌(gui)輕(qing)易(yi)的(de)(de)(de)高精(jing)度(du)(du)線(xian)性(xing)運(yun)(yun)動(dong)(dong)(dong)，并將摩擦系(xi)數降至平(ping)常傳統(tong)滑(hua)動(dong)(dong)(dong)導(dao)(dao)(dao)引的(de)(de)(de)五十分之(zhi)一，能輕(qing)易(yi)地達到很高的(de)(de)(de)定(ding)位(wei)精(jing)度(du)(du)。滑(hua)塊跟導(dao)(dao)(dao)軌(gui)間(jian)(jian)末制(zhi)單元設計，使線(xian)形導(dao)(dao)(dao)軌(gui)同時(shi)承(cheng)受上下左右(you)等各(ge)方向的(de)(de)(de)負荷(he)，回流系(xi)統(tong)及(ji)精(jing)簡化(hua)的(de)(de)(de)結(jie)構設計讓線(xian)性(xing)導(dao)(dao)(dao)軌(gui)有更平(ping)順(shun)且低噪(zao)音的(de)(de)(de)運(yun)(yun)動(dong)(dong)(dong)。

滑塊-使運動(dong)由(you)曲線(xian)(xian)轉變為直(zhi)線(xian)(xian)。

直線(xian)導(dao)軌(gui)主要(yao)是(shi)用(yong)(yong)在(zai)精(jing)度要(yao)求(qiu)比較(jiao)高(gao)(gao)的(de)機(ji)(ji)(ji)械(xie)結構上,直線(xian)導(dao)軌(gui)的(de)移動(dong)(dong)(dong)(dong)元(yuan)件和固定元(yuan)件之間(jian)不用(yong)(yong)中間(jian)介質，而(er)用(yong)(yong)滾(gun)動(dong)(dong)(dong)(dong)鋼球。因為滾(gun)動(dong)(dong)(dong)(dong)鋼球適應(ying)于高(gao)(gao)速運(yun)動(dong)(dong)(dong)(dong)、摩擦系數小、靈敏度高(gao)(gao)，滿足運(yun)動(dong)(dong)(dong)(dong)部件的(de)工作要(yao)求(qiu)，被廣泛應(ying)用(yong)(yong)在(zai)自動(dong)(dong)(dong)(dong)化機(ji)(ji)(ji)械(xie)上比較(jiao)多(duo),像磨床、銑床、車(che)床、檢測儀器設備(bei)、木工機(ji)(ji)(ji)械(xie)、搬運(yun)機(ji)(ji)(ji)械(xie)、傳送裝置、自動(dong)(dong)(dong)(dong)化機(ji)(ji)(ji)械(xie)、半導(dao)體機(ji)(ji)(ji)械(xie)、包裝機(ji)(ji)(ji)械(xie)、機(ji)(ji)(ji)械(xie)手臂、自動(dong)(dong)(dong)(dong)化機(ji)(ji)(ji)床、激光(guang)行業、汽車(che)制造、新能(neng)源等行業。