直線軸承支承的附加密封裝置可以有 效地防止外界異物入侵，但這種附加密封裝置將增 大機構的軸向尺寸，給使用和安裝維修帶來不便，同時其密封性能也受到軸徑和殼體相配部位的加工精度及行位公差的影響。而帶密封的軸承既可以有一個良好的密封潤滑環(huán)境，又能解決支承部位的難題，同時也可省去復雜的潤滑系統(tǒng)。

The additional sealing device supported by linear bearing can effectively prevent the invasion of foreign matters, but this additional sealing device will increase the axial size of the mechanism, and bring inconvenience to the use, installation and maintenance. At the same time, its sealing performance is also affected by the machining accuracy and line position tolerance of shaft diameter and shell matching parts. The bearing with seal can not only have a good sealing and lubrication environment, but also solve the problem of supporting parts, and save the complex lubrication system.

所以在thk直線軸承結構緊湊.密封要求嚴格的部位，均建議使用密封的自身密封除了具有良好的防塵.密封效果外，還能在運轉過程中不補給潤滑劑而保持良好的運轉狀態(tài)，減少了維修費用。

Therefore, it is recommended to use the self sealing of THK linear bearing where the structure of THK linear bearing is compact and the sealing requirements are strict. In addition to having good dust-proof and sealing effect, the self sealing of THK linear bearing can also maintain good operation state without replenishing lubricant during operation, thus reducing the maintenance cost.

直線軸承的自身密封按結構形式分為接觸式和非接觸式密封。按接觸形式可軸承座分為徑向密封和軸向密封。非接觸式密封一般有帶防塵蓋和橡膠密封圈兩種。按密封圈的構造可分為單唇密封和雙唇密封。

The self seal of linear bearing can be divided into contact seal and non-contact seal according to its structure. According to the contact form, the bearing seat can be divided into radial seal and axial seal. There are two kinds of non-contact seals: dust cover and rubber sealing ring. According to the structure of the seal ring can be divided into single lip seal and double lip seal.

防塵蓋密封間隙大，只適于防塵，橡轉盤軸承膠密封圈密封間隙小，有較好的密封效果。橡膠密封圈唇口是以一定的貼合力與軸承旋轉部位過盈接觸，從而起到良好的防塵密封效果，但其極限轉速較低和摩擦力矩較大。接觸式密封一般只有橡膠密封圈極其輔助零件。

The sealing clearance of the dust cover is large, which is only suitable for dust prevention. The rubber rotary bearing rubber sealing ring has small sealing clearance and good sealing effect. The lip of the rubber seal ring is in interference contact with the rotating part of the bearing with a certain adhesive force, so as to have a good dust-proof sealing effect, but its limit speed is low and the friction torque is large. Generally, the contact seal only has rubber seal ring and its auxiliary parts.