直線(xian)(xian)(xian)(xian)導軌又稱線(xian)(xian)(xian)(xian)軌、滑(hua)軌、線(xian)(xian)(xian)(xian)性導軌、線(xian)(xian)(xian)(xian)性滑(hua)軌，用于高精或(huo)高速(su)直線(xian)(xian)(xian)(xian)往復運動場合，且可(ke)(ke)以承擔一(yi)定的扭(niu)矩(ju)，可(ke)(ke)在高負載的情況(kuang)下實現(xian)高精度的直線(xian)(xian)(xian)(xian)運動。

直(zhi)線(xian)導(dao)(dao)軌(gui)(gui)(gui)(gui)運(yun)(yun)動(dong)(dong)(dong)的作用(yong)(yong)是(shi)用(yong)(yong)來支撐和引導(dao)(dao)運(yun)(yun)動(dong)(dong)(dong)部件(jian)，按給定(ding)(ding)的方(fang)向做(zuo)往復直(zhi)線(xian)運(yun)(yun)動(dong)(dong)(dong)。　直(zhi)線(xian)軸承主(zhu)要(yao)用(yong)(yong)在(zai)(zai)自動(dong)(dong)(dong)化機械上比較多,像直(zhi)線(xian)導(dao)(dao)軌(gui)(gui)(gui)(gui)主(zhu)要(yao)是(shi)用(yong)(yong)在(zai)(zai)精(jing)度(du)要(yao)求(qiu)比較高的機械結(jie)(jie)構上,直(zhi)線(xian)導(dao)(dao)軌(gui)(gui)(gui)(gui)的移動(dong)(dong)(dong)元(yuan)件(jian)和固定(ding)(ding)元(yuan)件(jian)之(zhi)間不用(yong)(yong)中間介質，而用(yong)(yong)滾動(dong)(dong)(dong)鋼(gang)(gang)球。可以理(li)解為(wei)是(shi)一種滾動(dong)(dong)(dong)導(dao)(dao)引，是(shi)由鋼(gang)(gang)珠在(zai)(zai)滑(hua)塊(kuai)跟導(dao)(dao)軌(gui)(gui)(gui)(gui)之(zhi)間無限滾動(dong)(dong)(dong)循環， 從而使負(fu)載平(ping)臺沿著導(dao)(dao)軌(gui)(gui)(gui)(gui)輕(qing)易的高精(jing)度(du)線(xian)性(xing)運(yun)(yun)動(dong)(dong)(dong)，并將摩擦(ca)系(xi)數降至平(ping)常(chang)傳統(tong)滑(hua)動(dong)(dong)(dong)導(dao)(dao)引的五十(shi)分之(zhi)一，能輕(qing)易地達到很(hen)高的定(ding)(ding)位精(jing)度(du)。滑(hua)塊(kuai)跟導(dao)(dao)軌(gui)(gui)(gui)(gui)間末制單元(yuan)設計，使線(xian)形導(dao)(dao)軌(gui)(gui)(gui)(gui)同(tong)時承受上下(xia)左右等各方(fang)向的負(fu)荷(he)，回流系(xi)統(tong)及精(jing)簡化的結(jie)(jie)構設計讓線(xian)性(xing)導(dao)(dao)軌(gui)(gui)(gui)(gui)有更(geng)平(ping)順且低噪音的運(yun)(yun)動(dong)(dong)(dong)。

滑塊-使運動由曲(qu)線轉變為(wei)直線。

直(zhi)線導軌主要是用(yong)在精度(du)要求比較(jiao)高(gao)的(de)機(ji)(ji)(ji)(ji)械(xie)結(jie)構上,直(zhi)線導軌的(de)移動元件和固定(ding)元件之間不用(yong)中間介質，而用(yong)滾動鋼球。因為滾動鋼球適應(ying)于(yu)高(gao)速運動、摩(mo)擦(ca)系數(shu)小、靈敏度(du)高(gao)，滿足運動部件的(de)工作要求，被廣泛應(ying)用(yong)在自動化(hua)機(ji)(ji)(ji)(ji)械(xie)上比較(jiao)多,像磨床(chuang)、銑床(chuang)、車(che)(che)床(chuang)、檢測儀器設(she)備、木(mu)工機(ji)(ji)(ji)(ji)械(xie)、搬運機(ji)(ji)(ji)(ji)械(xie)、傳(chuan)送裝置、自動化(hua)機(ji)(ji)(ji)(ji)械(xie)、半導體機(ji)(ji)(ji)(ji)械(xie)、包裝機(ji)(ji)(ji)(ji)械(xie)、機(ji)(ji)(ji)(ji)械(xie)手臂、自動化(hua)機(ji)(ji)(ji)(ji)床(chuang)、激(ji)光行(xing)業(ye)、汽車(che)(che)制造、新(xin)能源等行(xing)業(ye)。