直線導(dao)軌(gui)又稱線軌(gui)、滑軌(gui)、線性導(dao)軌(gui)、線性滑軌(gui)，用(yong)于高精或高速直線往復運動(dong)(dong)場合(he)，且可(ke)以承擔一定的扭矩，可(ke)在高負(fu)載的情況下實現高精度的直線運動(dong)(dong)。

直線(xian)導軌(gui)運動(dong)(dong)(dong)(dong)的(de)(de)作用(yong)是(shi)用(yong)來支撐和引(yin)導運動(dong)(dong)(dong)(dong)部件(jian)，按(an)給定的(de)(de)方向做(zuo)往復直線(xian)運動(dong)(dong)(dong)(dong)。　直線(xian)軸(zhou)承主要用(yong)在(zai)自動(dong)(dong)(dong)(dong)化(hua)機(ji)械(xie)上(shang)比(bi)較多,像直線(xian)導軌(gui)主要是(shi)用(yong)在(zai)精度(du)(du)(du)要求比(bi)較高(gao)的(de)(de)機(ji)械(xie)結(jie)構上(shang),直線(xian)導軌(gui)的(de)(de)移動(dong)(dong)(dong)(dong)元件(jian)和固定元件(jian)之(zhi)間不用(yong)中間介質，而(er)用(yong)滾動(dong)(dong)(dong)(dong)鋼(gang)球。可(ke)以(yi)理解(jie)為是(shi)一種滾動(dong)(dong)(dong)(dong)導引(yin)，是(shi)由鋼(gang)珠在(zai)滑(hua)塊(kuai)跟導軌(gui)之(zhi)間無(wu)限(xian)滾動(dong)(dong)(dong)(dong)循環， 從(cong)而(er)使(shi)負(fu)(fu)載平(ping)(ping)臺沿著導軌(gui)輕(qing)易的(de)(de)高(gao)精度(du)(du)(du)線(xian)性運動(dong)(dong)(dong)(dong)，并(bing)將摩擦系數降至(zhi)平(ping)(ping)常(chang)傳統滑(hua)動(dong)(dong)(dong)(dong)導引(yin)的(de)(de)五十分(fen)之(zhi)一，能輕(qing)易地達到很高(gao)的(de)(de)定位精度(du)(du)(du)。滑(hua)塊(kuai)跟導軌(gui)間末制單元設計，使(shi)線(xian)形(xing)導軌(gui)同(tong)時承受上(shang)下左右(you)等各(ge)方向的(de)(de)負(fu)(fu)荷，回流系統及精簡化(hua)的(de)(de)結(jie)構設計讓線(xian)性導軌(gui)有更平(ping)(ping)順且低(di)噪(zao)音的(de)(de)運動(dong)(dong)(dong)(dong)。

滑(hua)塊-使運(yun)動由曲(qu)線轉變為直線。

直(zhi)線導(dao)(dao)軌主要是用(yong)(yong)在精度要求比(bi)較高(gao)(gao)的機(ji)械(xie)(xie)(xie)結構上,直(zhi)線導(dao)(dao)軌的移動(dong)元件(jian)(jian)和固定元件(jian)(jian)之間(jian)不用(yong)(yong)中間(jian)介質，而用(yong)(yong)滾動(dong)鋼(gang)球(qiu)。因為滾動(dong)鋼(gang)球(qiu)適應于高(gao)(gao)速運(yun)動(dong)、摩擦系數小、靈敏度高(gao)(gao)，滿足運(yun)動(dong)部(bu)件(jian)(jian)的工作(zuo)要求，被廣泛應用(yong)(yong)在自動(dong)化(hua)機(ji)械(xie)(xie)(xie)上比(bi)較多,像磨床、銑床、車床、檢測儀(yi)器設備、木工機(ji)械(xie)(xie)(xie)、搬運(yun)機(ji)械(xie)(xie)(xie)、傳(chuan)送裝置(zhi)、自動(dong)化(hua)機(ji)械(xie)(xie)(xie)、半(ban)導(dao)(dao)體機(ji)械(xie)(xie)(xie)、包裝機(ji)械(xie)(xie)(xie)、機(ji)械(xie)(xie)(xie)手(shou)臂、自動(dong)化(hua)機(ji)床、激光行業(ye)、汽車制(zhi)造、新能源等(deng)行業(ye)。