直線導軌(gui)又稱線軌(gui)、滑軌(gui)、線性導軌(gui)、線性滑軌(gui)，用(yong)于高精或(huo)高速(su)直線往復運動場(chang)合，且可以承擔一定的扭(niu)矩，可在高負(fu)載的情況下實(shi)現高精度的直線運動。

直(zhi)線(xian)(xian)導(dao)(dao)軌(gui)運動(dong)(dong)的(de)(de)作用(yong)(yong)是(shi)(shi)(shi)用(yong)(yong)來支撐和(he)引(yin)導(dao)(dao)運動(dong)(dong)部件(jian)，按給定(ding)的(de)(de)方向做往復直(zhi)線(xian)(xian)運動(dong)(dong)。　直(zhi)線(xian)(xian)軸承主(zhu)要(yao)用(yong)(yong)在自動(dong)(dong)化機械上比較多,像直(zhi)線(xian)(xian)導(dao)(dao)軌(gui)主(zhu)要(yao)是(shi)(shi)(shi)用(yong)(yong)在精(jing)度要(yao)求比較高(gao)的(de)(de)機械結(jie)構上,直(zhi)線(xian)(xian)導(dao)(dao)軌(gui)的(de)(de)移動(dong)(dong)元件(jian)和(he)固定(ding)元件(jian)之間(jian)不用(yong)(yong)中間(jian)介質，而用(yong)(yong)滾(gun)動(dong)(dong)鋼(gang)球。可(ke)以理解為是(shi)(shi)(shi)一(yi)種滾(gun)動(dong)(dong)導(dao)(dao)引(yin)，是(shi)(shi)(shi)由鋼(gang)珠在滑塊跟(gen)導(dao)(dao)軌(gui)之間(jian)無限滾(gun)動(dong)(dong)循環， 從而使負(fu)載平臺沿(yan)著導(dao)(dao)軌(gui)輕易的(de)(de)高(gao)精(jing)度線(xian)(xian)性(xing)運動(dong)(dong)，并(bing)將(jiang)摩擦(ca)系(xi)數降(jiang)至(zhi)平常傳統滑動(dong)(dong)導(dao)(dao)引(yin)的(de)(de)五十分之一(yi)，能輕易地達到很高(gao)的(de)(de)定(ding)位精(jing)度。滑塊跟(gen)導(dao)(dao)軌(gui)間(jian)末制單元設計，使線(xian)(xian)形導(dao)(dao)軌(gui)同時承受上下左(zuo)右等(deng)各方向的(de)(de)負(fu)荷(he)，回流系(xi)統及精(jing)簡(jian)化的(de)(de)結(jie)構設計讓線(xian)(xian)性(xing)導(dao)(dao)軌(gui)有更平順且低噪音的(de)(de)運動(dong)(dong)。

滑塊(kuai)-使運動由曲線轉變為直(zhi)線。

直線(xian)導(dao)軌(gui)主要(yao)是用(yong)在(zai)精度要(yao)求比較高(gao)的機(ji)(ji)械(xie)結構上,直線(xian)導(dao)軌(gui)的移動(dong)(dong)(dong)元(yuan)件(jian)和固定(ding)元(yuan)件(jian)之間(jian)不用(yong)中(zhong)間(jian)介(jie)質，而用(yong)滾(gun)動(dong)(dong)(dong)鋼(gang)球。因為(wei)滾(gun)動(dong)(dong)(dong)鋼(gang)球適應于高(gao)速運(yun)動(dong)(dong)(dong)、摩擦系數小(xiao)、靈敏(min)度高(gao)，滿足運(yun)動(dong)(dong)(dong)部件(jian)的工作要(yao)求，被廣泛應用(yong)在(zai)自(zi)動(dong)(dong)(dong)化機(ji)(ji)械(xie)上比較多,像磨床、銑床、車床、檢測儀器設(she)備、木工機(ji)(ji)械(xie)、搬運(yun)機(ji)(ji)械(xie)、傳送(song)裝(zhuang)置、自(zi)動(dong)(dong)(dong)化機(ji)(ji)械(xie)、半導(dao)體機(ji)(ji)械(xie)、包裝(zhuang)機(ji)(ji)械(xie)、機(ji)(ji)械(xie)手臂、自(zi)動(dong)(dong)(dong)化機(ji)(ji)床、激光行業、汽(qi)車制造、新能源(yuan)等(deng)行業。