直线轴承支承的附加密封装置可以有 效地防止外界异物入侵，但这种附加密封装置将增 大机构的轴向尺寸，给使用和安装维修带来不便，同时其密封性能也受到轴径和壳体相配部位的加工精度及行位公差的影响。而带密封的轴承既可以有一个良好的密封润滑环境，又能解决支承部位的难题，同时也可省去复杂的润滑系统。

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直线轴承结构紧凑.密封要求严格的部位，均建议使用密封的自身密封除了具有良好的防尘.密封效果外，还能在运转过程中不补给润滑剂而保持良好的运转状态，减少了维修费用。

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.

直线轴承的自身密封按结构形式分为接触式和非接触式密封。按接触形式可轴承座分为径向密封和轴向密封。非接触式密封一般有带防尘盖和橡胶密封圈两种。按密封圈的构造可分为单唇密封和双唇密封。

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.

防尘盖密封间隙大，只适于防尘，橡转盘轴承胶密封圈密封间隙小，有较好的密封效果。橡胶密封圈唇口是以一定的贴合力与轴承旋转部位过盈接触，从而起到良好的防尘密封效果，但其极限转速较低和摩擦力矩较大。接触式密封一般只有橡胶密封圈极其辅助零件。

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.