CARB toroidal roller bearings can accommodate axial displacement of the shaft relative to the housing within the bearing. The permissible axial displacement from the normal position of one bearing ring relative to the other is limited by two criteria:
Displacement of the roller set
Misalignment as well as axial displacement influences the axial position of the rollers in a CARB bearing (fig. 1). The rollers should not protrude from the side face of a bearing ring (fig. 2) or make contact with a retaining ring (fig. 3) or seal. To accommodate the displacement of the roller and cage assembly, free space must be provided on both sides of the bearing (→ Free space on both sides of the bearing).
Sufficient radial internal clearance
CARB bearings should always operate with radial internal clearance. The axial position of the rollers influences the radial internal clearance. The typical clearance window for a CARB bearing is illustrated in diagram 1. The diagram also illustrates calculation examples 2 and 3 (→ Calculating the permissible axial displacement).
The permissible axial displacement is obtained from the smaller of these two limitations.