SELECTION OF ROLLING ELEMENT BEARINGS
DEEP GROOVE BALL BEARING
Selection procedure :
Given Data:
Axial Load on the bearing – Fa
Radial Load on the bearing – Fr.
Service conditions, Speed, & Diameter of the shaft.
STEP 1: Determine the ratio Fa/Fr
STEP 2: Assume e value. Refer P.4.4
STEP 3: Find out the radial factor X, and the thrust factor Y corresponding to the assumed e
value, based on the condition whether Fa/Fr < e (or) Fa/Fr > e (Refer P.4.4.)
STEP 4: Assume the service factor S, based on service conditions. Refer P 4.2
STEP 5: Calculate the equivalent load P. Use the equation on P 4.2.
STEP 6: Calculate the expected life of the bearing in number of revolutions. (Assume the
bearing life in hours, if not given in the problem, referring to P 4.5.)
STEP 7: Calculate the required dynamic load capacity. Use the equation on P 4.2.
STEP 8: Select the bearing from the bearing Catalogue, which has got more dynamic load
capacity than required. If the bearing with the required load capacity is not available
in the series assumed, refer to the next series and select the appropriate bearing.
STEP 9: Calculate Fa/Co, and find out the corresponding e value by interpolation. (C o is the
static load capacity of the selected bearing.
STEP 10: Find out, by interpolation, the factors X and Y corresponding to the e value, based on
the condition whether Fa/Fr < e or > e
STEP 11: Calculate the required dynamic load capacity as done in steps 5 to7. If this value is
less than the load capacity of the bearing already selected, then the selected bearing
will satisfy the design requirements.
STEP 12: If the required dynamic load capacity calculated in STEP 11 is greater than that of
the selected bearing, refer the catalogue, and again select a new bearing with more
dynamic load capacity than required.
STEP 13: Repeat steps 9,10 and 11 till the required load capacity is less than that of the
selected bearing
If the deep groove ball bearing with the required load carrying capacity is not
available in the bearing catalogue, suggest some other type of bearing
STEP 14: Write down the specification of the bearing selected.
SELF ALIGNING BALL BEARINGS AND SPHERICAL ROLLER BEARINGS
Selection procedure :
STEP 1: Determine the ratio Fa/Fr.
STEP 2: Select a bearing depending on the diameter of the shaft. (assume diameter if not given)
STEP 3: Find out the radial factor X and the thrust factor Y corresponding to the selected
bearing based on the condition whether Fa/Fr < e or > e (Refer P 4.4.).
STEP 4 to 7: The same as for deep groove ball bearing.
STEP 8: Refer the bearing catalogue and select a bearing which has got more dynamic load
capacity than required. If yes, the selected bearing is acceptable.
If not, then a bearing of the same diameter from a higher series may be tried. If a
bearing from a higher series is selected, use the corresponding X and Y values, determine again
the dynamic load capacity of the selected bearing and then repeat Step 8. If such a bearing is
not available in the higher series then an increase in diameter is called for. So a bearing with a
larger diameter may be selected repeating the steps given above.
STEP 9: Write down the specification of the bearing.
STEP 10: If a bearing of the type required to suit the load requirements could not be selected,
suggest some other type of bearing.