Calculating the axial load for bearings mounted singly or paired in tandem

When a radial load is applied to a single row tapered roller bearing, the load is transmitted from one raceway to the other at an angle to the bearing axis and an internal axial load is induced. This should be considered when calculating the equivalent bearing loads for bearing applications consisting of two single bearing arrangements and/or bearing pairs arranged in tandem.

Table 1 provides the necessary equations for various bearing applications and load cases. The equations are valid under the following conditions:

  • the bearings are adjusted against each other to practically zero clearance, but without any preload
  • bearing A is subjected to a radial load FrA and bearing B to a radial load FrB
  • both FrA and FrB are always considered positive, even when they act in a direction opposite to that shown in the figures
  • the radial loads act at the pressure centres of the bearings (→ distance a in the product table)

Ka is the external axial force acting on the shaft or on the housing. Load cases 1c and 2c are also valid when Ka = 0.
Values of the calculation factor Y are listed in the product table.

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