Page 686 - Rollingbearings

8 Tapered roller bearings
Matched bearings arranged
back-to-back

The distance a between the pressure centres
of two matched bearings arranged back-to-
back is signiicant when compared with the
distance L between the geometric centres of
the matched bearings and the other bearing
(ig. 20) Therefore, it is necessary to calcu-
late the magnitude of the load acting on the
bearing pair and also the distance a at
1
which the load acts. The magnitude of the
radial load can be obtained using:

L 1
F = JKK K r Fig. 20
r
L – a 1
Matched bearings arranged back-to-back, radial load
where
F = radial load acting on a bearing pair [kN] ! !!
r
K = radial force acting on the shaft [kN] L
r
L = distance between the geometric centres
of the two bearing positions [mm]
L = distance between the centre of bearing
1
position I and the point of action of the
force K [mm]
r
a = distance between the bearing pressure
= a 1
centres [mm] (product table, page 754) K a F a
a = distance between the geometric centre 0
1
of the matched bearings and the point
of action of the radial load F [mm]
r
• diagram 2 F r
• calculation factor Y , product table
8 The distance a can be determined from K r
2
1
diagram 2 by making an initial assump-
tion for F and if necessary followed by L 1 a
r
several iterative calculations.

Diagram 2
Distance of point of action of radial load
a 1
—
a
0,5

0,4
0,3

0,2

0,1

0
0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0
F a 1,5 Y 2

F r

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