Linear guidance

Slideways are one of the most important components in machine tools. They are part of the machine's mechanical core, and make a major contribution to its precision, performance and service life.

Today, there are various types of guardrail, the most important of which are :

• direct contact slides ;

• hydrostatic slides ;

• rolling element slides.

To meet the ever-increasing demands of machine builders, slideways are required to have an ever-increasing number of properties, such as :

• high operating and positioning accuracy (no backlash) ;

• high rigidity ;

• high static and dynamic load capacities ;

• good damping properties ;

• good breaking strength ;

• good sealing ;

• simple installation.

To date, there are no slides that have all these properties and meet all the requirements in the best possible way. There is a wide choice, but experience shows that the rolling element slide is best suited to the defined requirements.

It's safe to say that part of the improvement in a rolling element guide is the reduction in the coefficient of slider-guide friction. Progress has been made, in particular by substituting rolling friction for sliding friction. Friction coefficients are reduced from 0.1 to 0.2 (sliding friction) to 0.01 to 0.002 (rolling friction).

The advantages of this type of guidance system mean that it can be used in virtually any industry.

It is therefore essential to be familiar with this type of technology, so as to be able to implement it on machines.

To this end, we will develop two important points:

• the stiffness of linear guides as a function of their design ;

• calculation of linear rolling bearings.