Linear guides can achieve high-precision linear motion under high load conditions and are often used in various precision motions. This article mainly introduces the common linear ball guides and linear roller guides in linear guides.
1. Linear Ball Guides
Linear ball guides are assembled from rails, sliders, balls, ball retainers, ball return grooves, etc. The main principle is to make the steel balls circulate through structures such as ball return grooves and ball retainers, thereby achieving low-friction linear motion of the slider on the rail. This structure determines the following basic characteristics of linear guides:
- Since its support body is a ball, it is a point-to-surface rolling contact, so the friction resistance is very small, and subtle movements can be performed to achieve high-precision positioning of control devices, etc.;
- Because the ball has its own rolling groove, the force on the ball rotating surface will be dispersed, so there is a larger allowable load;
- Linear guides are not easy to generate friction heat during operation, and are not easy to deform due to heat, so they are suitable for high-speed and high-precision movement;
- Usually, the contact angle of each ball row is 45°, so that the four action directions on the slider (radial, reverse radial and lateral) have the same rated load.
2. Linear Roller Guide
The most direct difference between linear roller guides and linear ball guides is their rolling medium. Ball linear guides use steel balls, while roller linear guides use steel columns.
- Since its supporting body is a roller, the contact with the slideway is a line-surface rolling contact. Compared with the ball type, under the same volume, it has higher rigidity and greater bearing capacity;
- The roller guide block can obtain higher sensitivity and high-performance planar linear motion. Under heavy load or variable load, the elastic deformation is small and smooth linear motion can be obtained without creeping;
- The roller guide block can improve the positioning accuracy of the machine because its rolling body, the roller, is well guided when rolling and can automatically center.
3. Difference
Different Motion Media
Linear ball guide: A guide rail that uses round balls as carriers. Roller linear guide: A guide rail that uses round columns as carriers.
Different Load
The motion medium of the linear roller guide is in line-surface rolling contact, and the motion medium of the linear ball guide is in point-surface rolling contact, so the roller linear guide has a stronger bearing capacity.
Of course, due to the different motion media, the structures of the two guides are also different, and the slider structure is naturally different.
Generally speaking, ball linear guides have high precision and low noise, and are suitable for high-speed and high-precision scenarios; roller guides have strong load-bearing capacity and are suitable for heavy-load and high-rigidity scenarios.
4. Precautions for Use
Correct Alignment: Make sure that the installation positions of the linear guide rails and sliders are correctly aligned to avoid unnecessary wear and failure.
Tightening Torque: Tighten the guide rails with the correct torque according to the manufacturer's specifications to ensure stability and safety.
Foundation Flatness: Make sure the installation base is flat to avoid deformation of the guide rail due to uneven base.
Matching Sliders: Make sure that the sliders used match the model and specifications of the guide rails to ensure optimal performance.
Adjust the Gap: If the gap between the guide rail and the slider is adjustable, make sure to adjust it appropriately according to the use requirements.
Summary
When choosing linear roller guides and linear ball guides, it is necessary to comprehensively consider factors such as specific application requirements, load requirements, movement speed and accuracy. Each guide has its specific advantages and applicable scenarios.
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