Linear bearings: what is it?

Linear bearings - this is the general term for a number of mechanical components necessary for the smooth movement of the carriage or bushing along the rail or shaft. These mechanisms can have a simple or complex device.

It should be remembered that in different sources linear bearings can be called differently. The most common names are:

• Rail guides.
• Linear Bushings (Linear).
• Linear bearings.

Today, a huge number of various modifications and series of linear displacement bushes has been invented and introduced to satisfy the various needs of many industrial sectors. Every year, with the growth in the industry of the number of new equipment, repairers and mechanics require more and more products called "linear bearings".

Unlike conventional mechanisms that move rotationally, the rail guides make translational movements.

This is what determines their arrangement.

• Moving part. These parts can be represented by needle or ball separators, rails, bushings of various modifications, carriages.
• Part of the movement. This can be a normal or screw shaft, a rail, a rolling bearing, etc.

Linear bearings are devices of various configurations and sizes, but they are all needed to carry a load ensuring a fixed and careful linear motion. Such mechanisms include devices with cross rollers and roller bearings.

The rarest members of the family are hydrostatic and magnetic linear bearings. However, it is these models that are used where particularly accurate or absolutely noiseless work is needed.

The most common modifications are linear plain bearings, the same guides, ball bushings.

The "representative" of the last species can move around the round shaft. In this case, it will consist of a cylinder in which balls travel through special paths in confined space. Rotational movement of the balls will ensure a free movement of the bushing for smooth operation of the entire mechanism.

A carriage can move along the rail. In this case, its movement will be ensured by independent chains of rolling block balls. They are rolled inside a specially cut in the rail grooves, pushing each other.

With a device of this kind , the frictional force will be much lower than the mechanism with the sleeve. Even more will reduce its forced supply of oil and special seals, preventing the ingress of impurities and contaminants into the mechanism.

What should I consider when choosing linear bearings?

• Loads and estimated life.
• The speed of the necessary process.
• Rigidity.
• The accuracy of the final result.
• Structural features of equipment.
• Restrictions on operation or installation.