SKF - Rolling Bearings

Loads
Calculating the axial load for bearings
mounted singly or paired in tandem
When a radial load is applied to a single row
angular contact ball 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 must be considered when
calculating the equivalent bearing loads for
bearing arrangements consisting of two single
bearings and/or bearing pairs arranged in
tandem.
The necessary equations are provided in
table 11 († page 496), for the various bearing
arrangements and load cases. The equations
are only valid if the bearings are adjusted
against each other to practically zero clearance,
but without any preload. In the arrangements
shown, bearing A is subjected to a radial load
F rA and bearing B to a radial load F rB . Both F rA
and F rB are always considered positive, even
when they act in the direction opposite to what
is shown in the figures. The radial loads act at
the pressure centres of the bearings († distance
a in the product tables).
The variable R from table 11 († page 496)
takes into account the contact conditions
inside the bearing. The values for R can be
obtained from diagram 1, as a function of the
ratio K a /C. K a is the external axial force acting
on the shaft or on the housing and C is the
basic dynamic load rating of the bearing, which
must accommodate the external axial force.
Use R = 1 for K a = 0.
Diagram 1
3
R
1,00
0,98
0,96
0,94
0,92
0,90
0,88
0,86
0,84
0,82
0,80
0 0,1 0,2 0,3 0,4 K a /C
495