直線導(dao)軌又稱線軌、滑軌、線性導(dao)軌、線性滑軌，用于高(gao)精(jing)或高(gao)速(su)直線往復運動場合，且可(ke)以承擔一定的扭矩，可(ke)在高(gao)負(fu)載的情況下實現高(gao)精(jing)度的直線運動。

直(zhi)(zhi)線(xian)導(dao)(dao)(dao)軌運(yun)(yun)(yun)動(dong)(dong)的作用(yong)是(shi)用(yong)來支(zhi)撐和引導(dao)(dao)(dao)運(yun)(yun)(yun)動(dong)(dong)部件(jian)，按給定的方向做往復(fu)直(zhi)(zhi)線(xian)運(yun)(yun)(yun)動(dong)(dong)。　直(zhi)(zhi)線(xian)軸承主(zhu)要用(yong)在自動(dong)(dong)化機(ji)械上比(bi)較多,像直(zhi)(zhi)線(xian)導(dao)(dao)(dao)軌主(zhu)要是(shi)用(yong)在精度(du)要求(qiu)比(bi)較高(gao)(gao)的機(ji)械結構上,直(zhi)(zhi)線(xian)導(dao)(dao)(dao)軌的移動(dong)(dong)元(yuan)件(jian)和固定元(yuan)件(jian)之間不用(yong)中間介質，而用(yong)滾(gun)(gun)動(dong)(dong)鋼球(qiu)。可以理解為是(shi)一種(zhong)滾(gun)(gun)動(dong)(dong)導(dao)(dao)(dao)引，是(shi)由鋼珠在滑塊跟(gen)(gen)導(dao)(dao)(dao)軌之間無限(xian)滾(gun)(gun)動(dong)(dong)循環， 從而使負載平(ping)臺沿著(zhu)導(dao)(dao)(dao)軌輕易(yi)的高(gao)(gao)精度(du)線(xian)性運(yun)(yun)(yun)動(dong)(dong)，并將摩擦系數降至平(ping)常傳統滑動(dong)(dong)導(dao)(dao)(dao)引的五(wu)十分之一，能輕易(yi)地達(da)到很高(gao)(gao)的定位精度(du)。滑塊跟(gen)(gen)導(dao)(dao)(dao)軌間末(mo)制單元(yuan)設(she)(she)計，使線(xian)形(xing)導(dao)(dao)(dao)軌同時承受上下左右等各方向的負荷，回流系統及精簡(jian)化的結構設(she)(she)計讓線(xian)性導(dao)(dao)(dao)軌有更平(ping)順(shun)且低噪音(yin)的運(yun)(yun)(yun)動(dong)(dong)。

滑塊-使運動由曲線(xian)轉變(bian)為直線(xian)。

直(zhi)線導軌主要(yao)是用在精度(du)(du)要(yao)求(qiu)比較高(gao)的機(ji)(ji)(ji)械(xie)結構上,直(zhi)線導軌的移(yi)動(dong)(dong)(dong)元(yuan)件(jian)和固(gu)定元(yuan)件(jian)之(zhi)間(jian)不用中間(jian)介質，而用滾(gun)動(dong)(dong)(dong)鋼球。因為滾(gun)動(dong)(dong)(dong)鋼球適應于高(gao)速運動(dong)(dong)(dong)、摩擦(ca)系數小、靈敏度(du)(du)高(gao)，滿足運動(dong)(dong)(dong)部件(jian)的工(gong)作要(yao)求(qiu)，被廣泛應用在自(zi)(zi)動(dong)(dong)(dong)化機(ji)(ji)(ji)械(xie)上比較多(duo),像磨床、銑床、車(che)床、檢測儀器設備(bei)、木工(gong)機(ji)(ji)(ji)械(xie)、搬運機(ji)(ji)(ji)械(xie)、傳送裝置、自(zi)(zi)動(dong)(dong)(dong)化機(ji)(ji)(ji)械(xie)、半導體機(ji)(ji)(ji)械(xie)、包裝機(ji)(ji)(ji)械(xie)、機(ji)(ji)(ji)械(xie)手臂、自(zi)(zi)動(dong)(dong)(dong)化機(ji)(ji)(ji)床、激光行業、汽車(che)制造、新能源(yuan)等行業。