Page 199 - domce

9 INTERNAL SELF-ALIGNING BALL & ROLLER BEARING UNITS

6. Limiting speed & lubrication

III
20

Bearing bore d, mm 15
Relubrication interval, h
I
II 10.0
400 30 000 9.0
8.0
200
20 000
7.0
100
6.0
50
30 10 000 5.0
20
4.0
10
7
5 000
4 000 3.0
500 3 000 B
C
Radial ball bearings 300 A
200 2 000
2.0
100
50
1 000
30 1.5
20

500
400
300
1.0
0.9
Spherical roller bearings

0.8

0.7

Fig. 6 Nomogram for grease life

EXAMPLE:
no = factor FL x limiting speed for
What is the grease life of a bearing 23240B running at
grease see Fig. 5 and Section 9
300 rev/min with a 15 kN radial load?
–page 174 -180 incl.
The limiting speed of this bearing for grease is 750 rpm.
n = actual rotational speed, rev/min.
C/P = 1610/15 kN = 107.3, and the fL is 1.0 from Fig. 5
C = Dynamic Load Rating.
therefore no = 750 rev/min.
(see Dimension Tables).
The ratio no/n is 750/300 = 2.5. A horizontal line is
P = Radial Load.
drawn from the point of bore d = 200 mm in fig. 6 to line
I. The point no/n = 2.5 on line II shall then be connected
with the horizontal line at line I. Where line III was
intersected give approximate grease life, i.e. 2500
hours.

195