Basic requirements for linear guide design

1.Steering accuracy

The guiding precision refers to the accuracy of the movement trajectory of the moving member as it moves along the guide surface of the guide rail. The main factors affecting the guiding precision are the geometrical accuracy of the guide surface of the guide rail, the type of the guide rail, the contact accuracy of the guide rail pair, the surface 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, and the guide rail and the support. Thermal deformation of the piece, etc.

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.

2. Precision retention

Accuracy retention refers to the ability to maintain the original geometric accuracy during the operation of the guide rail. The accuracy of the guide rail is mainly determined by the wear resistance of the guide rail and the dimensional stability. The wear resistance is related to the material matching of the guide rail pair, the force, the machining accuracy, the lubrication method and the performance of the guard. In addition, the residual stress in the guide rail and its support member also affects the precision retention of the guide rail.

3. Motion sensitivity and positioning accuracy

Motion sensitivity refers to the minimum stroke that a moving member can achieve; positioning accuracy refers to the ability of a moving member to stop at a 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.

4. Movement stability

The smoothness of the guide rail movement 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 guide rail material, the lubrication condition, the nature of the lubricant and the stiffness of the transmission system of the guide rail movement.

5. Vibration resistance and stability

Vibration resistance refers to the ability of the rail pair to withstand forced vibration and shock, while stability refers to the performance of self-excited vibrations under given operating conditions.

6. Stiffness

The ability of the guide rail to resist deformation. Deformation will affect the relative position and guiding accuracy between the components, which 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 guide body, and both should be considered.

7. Structural processability

Structural manufacturability refers to the ease of processing of the rail pair (including the components of the rail pair). Under the premise of meeting the design requirements, it should be as convenient as possible to manufacture and maintain, and the cost is low.


Post time: Jul-22-2019