直線(xian)導軌(gui)又稱(cheng)線(xian)軌(gui)、滑(hua)軌(gui)、線(xian)性導軌(gui)、線(xian)性滑(hua)軌(gui)，用于高精或(huo)高速直線(xian)往復運動(dong)場合，且可以(yi)承擔一定的扭矩，可在高負載的情(qing)況下實現(xian)高精度的直線(xian)運動(dong)。

直(zhi)線(xian)(xian)導(dao)軌(gui)運(yun)動(dong)(dong)的(de)(de)(de)作用是(shi)(shi)用來(lai)支撐和引導(dao)運(yun)動(dong)(dong)部件，按給定的(de)(de)(de)方向做往(wang)復直(zhi)線(xian)(xian)運(yun)動(dong)(dong)。　直(zhi)線(xian)(xian)軸承主要用在自動(dong)(dong)化機(ji)械上比(bi)較多,像直(zhi)線(xian)(xian)導(dao)軌(gui)主要是(shi)(shi)用在精(jing)度(du)要求比(bi)較高(gao)(gao)的(de)(de)(de)機(ji)械結構(gou)上,直(zhi)線(xian)(xian)導(dao)軌(gui)的(de)(de)(de)移動(dong)(dong)元件和固定元件之(zhi)間(jian)不用中間(jian)介質，而用滾(gun)動(dong)(dong)鋼球。可以理解為是(shi)(shi)一種滾(gun)動(dong)(dong)導(dao)引，是(shi)(shi)由(you)鋼珠(zhu)在滑(hua)塊跟導(dao)軌(gui)之(zhi)間(jian)無限滾(gun)動(dong)(dong)循環， 從而使負(fu)載平臺沿著導(dao)軌(gui)輕(qing)易的(de)(de)(de)高(gao)(gao)精(jing)度(du)線(xian)(xian)性(xing)(xing)運(yun)動(dong)(dong)，并將(jiang)摩擦系數降至平常傳統(tong)滑(hua)動(dong)(dong)導(dao)引的(de)(de)(de)五十分之(zhi)一，能輕(qing)易地達到很高(gao)(gao)的(de)(de)(de)定位精(jing)度(du)。滑(hua)塊跟導(dao)軌(gui)間(jian)末制單元設(she)計，使線(xian)(xian)形導(dao)軌(gui)同時承受上下左右等各方向的(de)(de)(de)負(fu)荷(he)，回流系統(tong)及精(jing)簡化的(de)(de)(de)結構(gou)設(she)計讓線(xian)(xian)性(xing)(xing)導(dao)軌(gui)有更平順且低噪(zao)音的(de)(de)(de)運(yun)動(dong)(dong)。

滑塊-使運動由曲線轉變為直線。

直(zhi)線導軌主要是用(yong)(yong)在(zai)(zai)精度(du)(du)要求比(bi)較高(gao)的(de)(de)機(ji)(ji)械(xie)(xie)結(jie)構上,直(zhi)線導軌的(de)(de)移(yi)動(dong)(dong)(dong)元件(jian)和固定元件(jian)之(zhi)間不用(yong)(yong)中間介質，而用(yong)(yong)滾動(dong)(dong)(dong)鋼(gang)球。因為滾動(dong)(dong)(dong)鋼(gang)球適應于高(gao)速運(yun)動(dong)(dong)(dong)、摩(mo)擦系數小、靈敏度(du)(du)高(gao)，滿足(zu)運(yun)動(dong)(dong)(dong)部(bu)件(jian)的(de)(de)工(gong)作要求，被廣泛應用(yong)(yong)在(zai)(zai)自動(dong)(dong)(dong)化機(ji)(ji)械(xie)(xie)上比(bi)較多(duo),像(xiang)磨床(chuang)(chuang)(chuang)、銑床(chuang)(chuang)(chuang)、車(che)床(chuang)(chuang)(chuang)、檢(jian)測儀器設備、木工(gong)機(ji)(ji)械(xie)(xie)、搬運(yun)機(ji)(ji)械(xie)(xie)、傳送(song)裝置、自動(dong)(dong)(dong)化機(ji)(ji)械(xie)(xie)、半導體機(ji)(ji)械(xie)(xie)、包(bao)裝機(ji)(ji)械(xie)(xie)、機(ji)(ji)械(xie)(xie)手臂、自動(dong)(dong)(dong)化機(ji)(ji)床(chuang)(chuang)(chuang)、激光行(xing)業、汽(qi)車(che)制(zhi)造(zao)、新(xin)能(neng)源等行(xing)業。