Page 114 - The Tribology Handbook

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Selection of rolling bearings A20

DETERMINATION OF BASIC DYNAMIC LOADING RATING
The followinig nomogram can be used for determining the from the rotational speed and the required rating life. The
ratio International Organisation for Standardisation (ISO)
defines the rating life of a group of apparently identical
C basic dynamic load rating of the required bearing
- -- rolling bearings as that completed or exceeded by 90% of
-
P equivalent load to be carried by the bearing that group before first evidence of fatigue develops. The
median life is approximately 5 times the rating life.
BALL BEARINGS ROLLER BEARINGS
Rating life Rating life
Speed Load Million hours Speed Load Million hours
revlmtn ratio revolutions Lh revlmin ratio revolutions Lh
20- C/P L - 200 C/P L - 200

30 - -300 - 300

40 - - 400 - 400
50 - - 500 - 500
60 - - 600 - 600
70 - - 700 - 700
80 - - 800 - 800
90 - - 900 - 900
100- - 1000 - 1000

150- - 1500 - 1500
200- - 2000 - 2000

300- - 3000 - 3000
400 - - 4000 - 4000

500- - 5000 - 5000
600 - - 6000 - 6000
700 - - 7000 - 7000
800 - - 8000 - 8000
900 - - 9000 - 9000
1000- - 10 000 - 10 000
1200
1500- - I5000 - 15 000
1800 -
2000 - - 20 000 - 20 000

3000- - 30 000 - 30 000

4000 - - 40 000 - 40 000
5000- - 50 000 - 50000
6000 - - 60 000 - 60 000
7000- - 70 000 - 70 000
8000- - 80 000 - 80000
9000 - - 90 000 - 90 000
10000- - 100 000 - 100 000

15000- - 150 000 - 150 000
20000- - 200 000 - 200 000

30 000 - - 300 000 - 300 000
Note: information on the calculation of load rating C and equivalent load P can be obtained from IS0 281:1990. Values of C for various
types of bearing can be obtained from the bearing manufacturers.
A20.1