Page 20 - february

METALWORKING EQUIPMENT AND TOOLS

CORRECT SELECTION OF THE LINEAR GUIDE

IMPORTANCE OF PRE-LOAD AND FRICTION
Some engineers often neglect important parameters of linear guides and carriages (traversing
units) in the design and manufacture of equipment. In addition to the accuracy class, load-
carrying capacity and modern technological innovations, such as the maintenance-free block
type, the system linear displacement there are a number of important characteristics that must
be considered in the design process.
PURPOSE OF PRE-TENSION
If the load is small and very smooth
movement is required, clearance can be
given to the linear rolling guides. In many Ball without preload
cases, however, preload is preferable Preload ball Ball diameter Roller diameter and
10 mm
length 10x10 mm
because it eliminates play in the guide and
increases the rigidity of the rolling guide. Effective preload: equivalent to 0.05 Co
The preload is achieved by pre-creating an Elastic deformation Roller without preload
internal stress in the contact area between
the raceways and the rolling elements. If
a load is applied to a pre-tensioned rolling
guide, then due to internal stresses, Preloaded roller
elastic deformations are less than without
preload, and the rigidity of the rolling guide Load N
increases (see Fig. 1).
Fig. 1. Dependence of the deformation of the rolling elements on their type
and applied load
ADJUSTING THE PRELOAD
The preload value is determined
taking into account the characteristics of the machines and equipment on which the rolling
guide is installed, and taking into account the nature of the load acting on the guide. Standard

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