直(zhi)(zhi)線(xian)導(dao)軌(gui)(gui)又稱線(xian)軌(gui)(gui)、滑軌(gui)(gui)、線(xian)性導(dao)軌(gui)(gui)、線(xian)性滑軌(gui)(gui)，用于(yu)高精或高速直(zhi)(zhi)線(xian)往復運動場合，且可以承擔一定的(de)扭(niu)矩，可在高負載的(de)情況下實現高精度的(de)直(zhi)(zhi)線(xian)運動。

直(zhi)線(xian)(xian)導(dao)軌(gui)(gui)運動(dong)(dong)(dong)的作用(yong)(yong)(yong)是(shi)用(yong)(yong)(yong)來支撐和引(yin)導(dao)運動(dong)(dong)(dong)部(bu)件，按(an)給定(ding)的方向做往復直(zhi)線(xian)(xian)運動(dong)(dong)(dong)。　直(zhi)線(xian)(xian)軸承主要(yao)用(yong)(yong)(yong)在(zai)(zai)自動(dong)(dong)(dong)化(hua)機械上(shang)比較(jiao)多,像直(zhi)線(xian)(xian)導(dao)軌(gui)(gui)主要(yao)是(shi)用(yong)(yong)(yong)在(zai)(zai)精(jing)度要(yao)求(qiu)比較(jiao)高的機械結構上(shang),直(zhi)線(xian)(xian)導(dao)軌(gui)(gui)的移動(dong)(dong)(dong)元件和固(gu)定(ding)元件之(zhi)間(jian)(jian)(jian)不用(yong)(yong)(yong)中間(jian)(jian)(jian)介(jie)質，而用(yong)(yong)(yong)滾(gun)動(dong)(dong)(dong)鋼球。可以(yi)理(li)解為是(shi)一種(zhong)滾(gun)動(dong)(dong)(dong)導(dao)引(yin)，是(shi)由(you)鋼珠在(zai)(zai)滑塊跟導(dao)軌(gui)(gui)之(zhi)間(jian)(jian)(jian)無限滾(gun)動(dong)(dong)(dong)循(xun)環， 從而使(shi)負(fu)載平(ping)臺沿著導(dao)軌(gui)(gui)輕易(yi)的高精(jing)度線(xian)(xian)性運動(dong)(dong)(dong)，并將摩擦系數(shu)降(jiang)至平(ping)常傳(chuan)統滑動(dong)(dong)(dong)導(dao)引(yin)的五十分之(zhi)一，能輕易(yi)地達到很高的定(ding)位精(jing)度。滑塊跟導(dao)軌(gui)(gui)間(jian)(jian)(jian)末制單元設(she)計，使(shi)線(xian)(xian)形導(dao)軌(gui)(gui)同時承受上(shang)下左右(you)等各方向的負(fu)荷，回流系統及精(jing)簡(jian)化(hua)的結構設(she)計讓(rang)線(xian)(xian)性導(dao)軌(gui)(gui)有(you)更平(ping)順且低噪(zao)音的運動(dong)(dong)(dong)。

滑塊-使運動由曲線轉變為直線。

直線導(dao)軌主要是(shi)用(yong)在精(jing)度(du)要求比(bi)較高的(de)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)結構上(shang),直線導(dao)軌的(de)移動(dong)(dong)元件和固定元件之間不用(yong)中間介質，而用(yong)滾動(dong)(dong)鋼球(qiu)。因為滾動(dong)(dong)鋼球(qiu)適應于(yu)高速運動(dong)(dong)、摩(mo)擦系(xi)數(shu)小、靈敏(min)度(du)高，滿足運動(dong)(dong)部件的(de)工作要求，被廣(guang)泛應用(yong)在自(zi)動(dong)(dong)化機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)上(shang)比(bi)較多,像(xiang)磨床、銑床、車床、檢(jian)測(ce)儀器設備、木工機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)、搬運機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)、傳送裝(zhuang)置、自(zi)動(dong)(dong)化機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)、半導(dao)體機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)、包裝(zhuang)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)、機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)手臂、自(zi)動(dong)(dong)化機(ji)(ji)(ji)床、激光行業(ye)、汽車制造、新(xin)能源等行業(ye)。