How is the precision grade ...

How is the precision grade of linear guideways divided？

Precision linear guideways is a industrial part, which can carry out linear reciprocating movement under high load. It is widely used in precision equipment, machine tools and instruments. But for different working conditions, there are different requirements for the accuracy of linear guide, and its accuracy also needs to be distinguished from different aspects. The following is to share with you the accuracy grade of precision linear guideways:

 

Seven parameters of the accuracy of precision linear guideways:

1. Dimensional tolerance of height H
2. Dimensional tolerance of width N
3. Variation of height H
4. Variation of width N
5. Running parallelism of block surface C to surface A
6. Running parallelism of block surface D to surface B
7. Accuracy of Running Parallelism

 

Accuracy grade classification of precision linear guideways:

1. Normal (C)
2. High (H)
3. Precision (P)
4. Super precision (SP)
5. Ultra precision (UP)

 

Totally, five classes. Please choose the class by referring the accuracy of applied equipment.

For example: Let’s take a precision linear guideways 100mm long as an example to check the running parallelism.

1. Normal (C):12μm
2. High (H):7μm
3. Precision (P):3μm
4. Super precision (SP):2μm
5. Ultra precision (UP):2μm

 

So what factors will affect the accuracy of the precision linear guideways?

1. The straightness of the precision linear guideways. The straightness standard of guide rail is generally reflected by its error value, which refers to the amount of deviation between the measured unit and the ideal unit.

2. Rigidity of the precision linear guideways. Due to the high-speed operation of the machine tool during the working process, the guide rail will directly produce friction and collision, resulting in the deformation of the linear guide due to stress. So the plane flatness of the guide rail, the load capacity, the material selection and the structural layout of precision linear guideways should strictly meet the design standards.

3. Roughness of the precision linear guideways surface. The roughness of the surface of the linear guide is usually determined by the hardness and material of the guide. When choosing the production of the precision linear guideways, reasonable and suitable production materials should be selected according to the actual situation, so as to reduce the possibility that the accuracy of the linear guideways may be affected.

4. Structure type of the precision linear guideways. The installation layout of linear guide rail and its own structure shape directly affect the precision index of machine tool. The most direct will affect the positioning and repeated positioning of machine tools.

 

In short, precision linear guideways accuracy standard specific refers to have more than one parameter, and specific level is divided into five level, but everybody when doing the selection of the linear guide, not only to investigate its precision, but also the load capacity, at the same time the size, friction, mute,installation requirements as well as our cost and so on are need to be considered! It is worth noting that different precision linear guideways manufacturers may customize their linear guide accuracy grade classification standards, there will be some subtle differences, we should pay attention to the specific parameter values!