Among the various accuracy indicators of linear guides, geometric accuracy and guide accuracy of the guide rail are relatively important. The geometric accuracy of guide rails includes the straightness between vertical and horizontal planes, the parallelism between guide rail surfaces, and the perpendicularity between guide rails; The guiding accuracy of a guide rail refers to the deviation between the motion trajectory of a moving part and a given direction, which mainly depends on the geometric accuracy of the guide rail itself and the clearance between the guide rails. The clearance between the guide rails mainly depends on the structure type, surface roughness, stiffness, and thermal deformation of the guide rail.

The main factors affecting the accuracy of the guide rail are as follows:

1. The straightness of the guide rail: It directly affects the parallelism between the guide rail surfaces and the perpendicularity between the guide rails

2. Rail stiffness: The rail will experience contact deformation, local deformation, and self deformation when subjected to force. Contact deformation is caused by the microscopic unevenness of the guide rail plane; Local deformation generally occurs in areas of stress concentration; The deformation of the guide rail itself refers to the overall deformation of the rail after bearing external loads, which is related to the material and layout of the guide rail.

3. The surface roughness of the guide rail mainly depends on the material, hardness, and grinding process of the guide rail.

4. The structural type of the guide rail directly affects the positioning accuracy, repeat positioning accuracy, and other precision indicators of the machine tool.