Tandem Bearing Operation
To meet the requirement that all rows support equal portions of theaxial forces from the extruder screw regardless of the load ratio C/P (where C is the dynamic load rating [N] and P the dynamic equivalent load [N]), the shaft sleeves and housing sleeves are specially designed so that the same deflection is achieved for each row. The geometry of the rings thus plays an important role in providing the optimum flow of power in the bearing (Figure 4). The shape of shaft washers and housing washers primarily effects the load distribution on the length of the cylindrical rollers. The design of shaft and housing washers allows both components to receive the same polysymmetric deformation. Although the washers under load are subject to elastic deformation, both raceways nonetheless remain almost parallel to each other (Figure 5).
Rolling element tilting or edge loading on the rolling elements, which lead to reduced service life, can thus be eliminated.
In addition to the equal deflection on each row mentioned above, in the case of six row and eight row tandem bearings the load distribution between the three row and four row tandem bearings must be achieved corresponding to their load carrying capacity. This can be done by matching the shaft sleeve and the housing sleeve.