Evaluation factors for the use of linear guides
The use of linear guides requires many factors, and some performance indicators need to be evaluated to ensure normal use and meet qualified indicators. The so-called performance indicators are mainly the following:
1, the precision of the guide rail
Accuracy persistence refers to the ability of the rail to maintain its original geometric accuracy during operation. The precision of the guide rail depends mainly on the wear resistance of the guide rail and the dimensional stability. Wear resistance is related to the force of the rail pair, processing accuracy, lubrication, and the performance of the guard. In addition, the residual stress in the guide rail and its support member also affects the precision of the guide rail.
2, the stability of the movement
The smoothness of the linear guide rail refers to the performance of the guide rail without creeping at low speed or slight movement. The smoothness is related to the structure of the guide rail, the matching of the materials, the lubrication condition, the nature of the lubricant and the stiffness of the transmission system of the guide rail movement.
3. Guide accuracy and thermal deformation of the guide rail and the support member.
The guiding precision refers to the accurate level of the trajectory of the moving member when it moves along the guiding surface of the linear guide. The main factors affecting the guiding precision are the geometrical accuracy of the imported linear guide bearing surface, the structural type of the guide rail, the contact accuracy of the guide rail pair, the appearance roughness, the rigidity of the guide rail and the support member, the oil film thickness of the guide rail pair and the oil film stiffness.
The geometric accuracy of a linear motion guide generally includes: straightness in a vertical plane and a horizontal plane; parallelism between the two rail faces. The geometric accuracy of the guide rail can be expressed by the error over the entire length of the guide rail or the error per unit length.
4. Stiffness characteristics of the guide rail This is especially important for precision machinery and instruments. The deformation of the guide rail includes the deformation of the guide rail of the guide rail of the main body, and the ability of the guide rail to resist deformation. The deformation will affect the relative position and guiding accuracy between the components. Both should be considered.
5, anti-vibration and stability
Stability refers to the performance of self-excited vibrations that do not occur under given operating conditions. Anti-vibration is the ability of the imported linear guide pair to accept forced vibration and shock.
6. Motion sensitivity and positioning accuracy of the guide rail
The motion sensitivity of the linear guide refers to the minimum stroke that the moving member can achieve; the positioning accuracy refers to the ability of the moving member to stop at the specified position as required. Motion sensitivity and positioning accuracy are related to factors such as rail type, friction characteristics, motion speed, transmission stiffness, and moving member quality.