直(zhi)線(xian)(xian)(xian)導軌又稱線(xian)(xian)(xian)軌、滑(hua)軌、線(xian)(xian)(xian)性導軌、線(xian)(xian)(xian)性滑(hua)軌，用于高(gao)精或高(gao)速直(zhi)線(xian)(xian)(xian)往復(fu)運動場合，且可以承(cheng)擔一定的扭矩，可在高(gao)負載的情況下實現高(gao)精度的直(zhi)線(xian)(xian)(xian)運動。

直線(xian)導(dao)(dao)軌(gui)運(yun)(yun)動(dong)(dong)的(de)(de)(de)(de)作用(yong)是用(yong)來支撐和引(yin)(yin)導(dao)(dao)運(yun)(yun)動(dong)(dong)部件(jian)，按(an)給定的(de)(de)(de)(de)方向做往復直線(xian)運(yun)(yun)動(dong)(dong)。　直線(xian)軸承主要用(yong)在(zai)自動(dong)(dong)化(hua)機械上(shang)比較(jiao)多,像直線(xian)導(dao)(dao)軌(gui)主要是用(yong)在(zai)精度要求比較(jiao)高的(de)(de)(de)(de)機械結構上(shang),直線(xian)導(dao)(dao)軌(gui)的(de)(de)(de)(de)移動(dong)(dong)元(yuan)件(jian)和固(gu)定元(yuan)件(jian)之間(jian)(jian)不用(yong)中間(jian)(jian)介(jie)質，而(er)用(yong)滾(gun)動(dong)(dong)鋼(gang)球。可(ke)以理解為是一(yi)種滾(gun)動(dong)(dong)導(dao)(dao)引(yin)(yin)，是由鋼(gang)珠在(zai)滑塊跟(gen)導(dao)(dao)軌(gui)之間(jian)(jian)無(wu)限滾(gun)動(dong)(dong)循(xun)環， 從而(er)使(shi)負載(zai)平臺沿著導(dao)(dao)軌(gui)輕(qing)易的(de)(de)(de)(de)高精度線(xian)性運(yun)(yun)動(dong)(dong)，并(bing)將摩擦系(xi)數(shu)降至平常傳統滑動(dong)(dong)導(dao)(dao)引(yin)(yin)的(de)(de)(de)(de)五十分(fen)之一(yi)，能輕(qing)易地達到很高的(de)(de)(de)(de)定位精度。滑塊跟(gen)導(dao)(dao)軌(gui)間(jian)(jian)末制單元(yuan)設計(ji)，使(shi)線(xian)形導(dao)(dao)軌(gui)同時(shi)承受上(shang)下左右等各方向的(de)(de)(de)(de)負荷，回流系(xi)統及精簡化(hua)的(de)(de)(de)(de)結構設計(ji)讓線(xian)性導(dao)(dao)軌(gui)有更平順且低(di)噪(zao)音的(de)(de)(de)(de)運(yun)(yun)動(dong)(dong)。

滑塊-使運動由曲線(xian)轉(zhuan)變為直線(xian)。

直(zhi)線(xian)導軌(gui)主要(yao)(yao)是用(yong)在(zai)精度(du)(du)要(yao)(yao)求比(bi)較高(gao)的(de)機(ji)械(xie)(xie)結構上,直(zhi)線(xian)導軌(gui)的(de)移(yi)動元(yuan)件(jian)和固定元(yuan)件(jian)之間不(bu)用(yong)中間介質，而用(yong)滾動鋼球。因為滾動鋼球適應于高(gao)速運動、摩擦系數小、靈(ling)敏度(du)(du)高(gao)，滿足(zu)運動部件(jian)的(de)工(gong)作要(yao)(yao)求，被廣泛應用(yong)在(zai)自動化機(ji)械(xie)(xie)上比(bi)較多,像磨床(chuang)(chuang)、銑床(chuang)(chuang)、車床(chuang)(chuang)、檢測(ce)儀器設備、木(mu)工(gong)機(ji)械(xie)(xie)、搬運機(ji)械(xie)(xie)、傳送(song)裝(zhuang)置、自動化機(ji)械(xie)(xie)、半導體機(ji)械(xie)(xie)、包(bao)裝(zhuang)機(ji)械(xie)(xie)、機(ji)械(xie)(xie)手(shou)臂、自動化機(ji)床(chuang)(chuang)、激光行(xing)業、汽車制造、新能源等行(xing)業。