直線導軌又(you)稱線軌、滑軌、線性導軌、線性滑軌，用(yong)于高(gao)(gao)精(jing)或高(gao)(gao)速直線往復(fu)運(yun)動場合，且可(ke)以(yi)承擔一定的扭(niu)矩，可(ke)在(zai)高(gao)(gao)負載的情況下實現高(gao)(gao)精(jing)度(du)的直線運(yun)動。

直線(xian)(xian)導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)運(yun)動(dong)的(de)(de)作用(yong)(yong)(yong)(yong)是(shi)用(yong)(yong)(yong)(yong)來支撐和引(yin)導(dao)(dao)(dao)(dao)(dao)運(yun)動(dong)部件，按給定(ding)的(de)(de)方向做往(wang)復直線(xian)(xian)運(yun)動(dong)。　直線(xian)(xian)軸承(cheng)(cheng)主要用(yong)(yong)(yong)(yong)在(zai)(zai)自動(dong)化機械上比(bi)較多(duo),像直線(xian)(xian)導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)主要是(shi)用(yong)(yong)(yong)(yong)在(zai)(zai)精度(du)要求(qiu)比(bi)較高的(de)(de)機械結(jie)構上,直線(xian)(xian)導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)的(de)(de)移動(dong)元件和固定(ding)元件之間(jian)不用(yong)(yong)(yong)(yong)中間(jian)介質(zhi)，而用(yong)(yong)(yong)(yong)滾(gun)動(dong)鋼球。可以理解為是(shi)一種滾(gun)動(dong)導(dao)(dao)(dao)(dao)(dao)引(yin)，是(shi)由鋼珠在(zai)(zai)滑(hua)塊(kuai)跟導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)之間(jian)無限滾(gun)動(dong)循(xun)環， 從而使負(fu)載(zai)平臺沿著(zhu)導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)輕(qing)易的(de)(de)高精度(du)線(xian)(xian)性運(yun)動(dong)，并將摩(mo)擦系數降至平常傳統滑(hua)動(dong)導(dao)(dao)(dao)(dao)(dao)引(yin)的(de)(de)五十分之一，能輕(qing)易地達到很高的(de)(de)定(ding)位精度(du)。滑(hua)塊(kuai)跟導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)間(jian)末制單元設計(ji)，使線(xian)(xian)形導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)同(tong)時承(cheng)(cheng)受上下左右等各方向的(de)(de)負(fu)荷，回流系統及(ji)精簡(jian)化的(de)(de)結(jie)構設計(ji)讓(rang)線(xian)(xian)性導(dao)(dao)(dao)(dao)(dao)軌(gui)(gui)(gui)(gui)有更平順且(qie)低(di)噪音的(de)(de)運(yun)動(dong)。

滑塊(kuai)-使(shi)運(yun)動由曲線轉變(bian)為(wei)直線。

直(zhi)線導(dao)軌主要(yao)是用(yong)(yong)(yong)在(zai)精(jing)度要(yao)求比(bi)較高的(de)機(ji)械(xie)結構(gou)上(shang),直(zhi)線導(dao)軌的(de)移動(dong)元(yuan)(yuan)件(jian)和固定元(yuan)(yuan)件(jian)之(zhi)間不用(yong)(yong)(yong)中間介質，而用(yong)(yong)(yong)滾動(dong)鋼球(qiu)(qiu)。因為滾動(dong)鋼球(qiu)(qiu)適應于高速(su)運動(dong)、摩擦系(xi)數小(xiao)、靈敏度高，滿足運動(dong)部件(jian)的(de)工作要(yao)求，被(bei)廣泛應用(yong)(yong)(yong)在(zai)自(zi)動(dong)化(hua)機(ji)械(xie)上(shang)比(bi)較多,像磨床、銑床、車床、檢(jian)測儀器(qi)設備、木(mu)工機(ji)械(xie)、搬運機(ji)械(xie)、傳送(song)裝置(zhi)、自(zi)動(dong)化(hua)機(ji)械(xie)、半(ban)導(dao)體(ti)機(ji)械(xie)、包裝機(ji)械(xie)、機(ji)械(xie)手(shou)臂、自(zi)動(dong)化(hua)機(ji)床、激光行業、汽車制(zhi)造、新能源等行業。