It is called FIXED to those systems or rolling cartridges, with capacity to absorb loads external AXIAL and RADIAL at the same time, with total absence of axial play.
For this condition, the system must form a compact and highly rigid “block”,and must be tightly tied to a casing by means of the existing screws in the cartridge flange. The expansion in the elements of the machines is a fact to which special attention must be paid since, if the elongation is not foreseen when designing the supports of the axis in question, serious operating problems may occur, including breakdowns considered “catastrophic”.
It is called FREE to those systems of rolling cartridges, with the capacity to move axially and absorbing only external RADIAL loads.
Due to the aforementioned, it is necessary to assemble on one of the parts of the shaft a support capable of moving in the presence of elongations caused by changes in temperature. This situation is successfully resolved through the application of this support with the possibility of moving as the axis expands.