Bearing description: 
  A groove or ridge of metal or other material that supports, holds, guides, and reduces friction in a moving device or device. A longitudinal groove or ridge on the surface of a guide rail used for guiding, securing machine parts, special equipment, instruments, etc. Guide rail, also known as sliding rail, linear guide rail, linear sliding rail, used for linear reciprocating motion occasions, has a higher load rating than linear bearings, while can bear a certain torque, can achieve high precision linear motion under high load. 

As a guide device, the guide rail shall have the following properties:

(1) Guiding accuracy mainly guides the accuracy of orbit motion. The main factors affecting the guiding accuracy are: the geometric accuracy and contact accuracy of the guide rail, the structural form of the guide rail, the stiffness and thermal deformation of the guide rail and its supporting parts, the oil film thickness and stiffness between the static (dynamic) press guide pair, etc.

(2) Accuracy retention is mainly determined by the wear resistance of the guide rail. The wear resistance is related to the material of the guide rail, the friction property of the guide pair, the pressure on the guide rail and its distribution law.

(3) The stiffness includes the self-stiffness and contact stiffness of the guide rail. It mainly depends on the shape of the guide rail, the size and the connection mode of the supporting parts and the stress status and other factors.

(4) Low speed motion stationary moving guide is easy to produce friction self-excited vibration when moving at low speed or trace displacement, namely crawling phenomenon. Crawling can reduce the accuracy of positioning or increase the roughness of the workpiece surface. 

Function of guide lubricant:

(1) Make the guide rail work as close to the liquid friction state as possible to reduce friction resistance, reduce driving power and improve efficiency.

(2) Reduce guide wear and prevent guide corrosion. The flowing lubricating oil also plays a washing role.

(3) Avoid crawling phenomenon under low speed and heavy load, and reduce vibration.

(4) Reduce friction heat at high speed to reduce thermal deformation. 


Protection of guide rail:

The protection of guide rail can prevent or reduce the wear of guide pair and prolong the life of guide rail. Protective devices are produced by special manufacturers and can be purchased.

There are many ways to protect the guide rail. The common protective cover is shown in Figure 1. Numerical control machine tools. Especially in the center of cutting, iron filings, coolant a lot, easy to enter the guide rail, increase guide wear; When the iron filings are large, the worktable is raised to affect the accuracy of the guide rail, so the steel plate telescopic protective cover is usually used. 

Characteristics of linear guide:

1. High positioning accuracy

2.Less wear, can maintain accuracy for a long time

3.Suitable for high-speed movement

4.Can bear the four-way load at the same time

5.Easy assembly and interchange

6.Simple lubrication structure 
 

Application:

  The sliding guide has the advantages of simple structure, convenient manufacture and high contact stiffness. However, the traditional sliding guide has large friction resistance, fast wear, large difference in dynamic and static friction coefficient, and easy to produce crawling phenomenon at low speed. In order to improve the positioning accuracy and motion stability of CNC machine tools, plastic guide rails have been widely used in CNC machine tools.