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Angular or 4-Point Contact Bearing Calculations

For angular contact and 4-point contact bearingscalculate Pwith X = 1.0 and Y= 0. Then recalculate P with X = 0.39 and Y= 0.76. Use the larger value of P to determine L10life.The equations are valid in the range of approxi-mately 100 hrs to 100,000 hrs of life. Extreme loads or speeds may result in a shorter life; while in less demanding applications, metal fatigue may never affect bearing service life.

Material,Conditiona
2 max 52100, Air melt1.0052100, Vacuum degassed1.50 52100, Air melt & TDC Plate2.00 52100, Vacuum melt, (CEVM)3.00440C, Air melt1.00440C, Vacuum melt (CEVM)3.00M50, Vacuum melt (CEVM)5.00M50, Vacuum re-melt (VIM-VAR)8.00
Capacity and fatigue life information is based on ANSI/ABMA Standard 9-1990 published by: The American Bearing Manufacturers Association, Inc., 1200 19th Street, NW, Suite 300, Washington, DC 20036-2401

Application Factor a

3

The application factor a is equal to 1.0 for mostapplications. Unusual or extreme conditions in certain applications such as low speed, shock loading, vibration, and extreme temperature may lower the application factor to 0.50. Contact your RBC Sales Engineer for help in determining this factor for your special applications.

Thin Section Ball Bearings - 16837 Adjustment Factors for Rating Life

3

If a bearing design and operation deviates signifi-cantly from normal, it may be necessary to use addi- tional factors to estimate the fatigue life L

n

.

L n = a
1 *a
2 *a
3 *L
10 hrs

Load and Speed Limitations

witha
1 = reliability factora

The load ratings shown in the product tables arenot additive. For combined simultaneous loading, an equivalent radial or thrust load must be considered. In general, C-Type bearings are designed for radial loading applications; moderate thrust and/or moment loading may be applied in combination with radial loading. For thrust loading applications use the A- Type bearing; any radial loading should only be applied in combination with thrust loading. X-Type bearings are primarily for reversing thrust and moment loading, pure radial loading should not be applied.The limiting speeds shown in the product tablesare based on standard lubrication. The unsealed bear- ing speeds are calculated assuming the bearings are lubricated with MIL-PRF-3150. Limiting speeds for sealed bearings are calculated assuming the bearings are lubricated with MIL-PRF-23827 grease. If bearings are lubricated with alternate oils or greases, new limit- ing speeds must be calculated, see page 30. processing, forming methods, heat treatment, andother manufacturing methods. Some commonly used material factors are listed below:

2 = material & processing factora
ENGINEERING 3 = application factor
DATA

Reliability Factor a

1

Reliability is the percentage of a group of appar-ently identical ball bearings that is expected to attain or exceed a specified life. For an individual bearing it is the probability that the bearing will attain or exceed a specified life. Typical bearing fatigue life is calculated for 90% reliability. The life adjustment factors for other reliability numbers are shown below.

Reliability %L
n Reliability Factor a
1 90L
10 1.0095L
5 .6296L
4 .5397L
3 .4498L
2 .3399L
1 .21

Material Factor a

2

For standard bearings the material factor a

2

isequal to 1.00. Factor a

2

is determined by material

29