NTN - Cylindrical and Tapered Roller Bearings

Engineering Section
The
These
values
thrust
of X
reactions
and Y are
are
determined
a critical
using
part
Table
of the
2:
Equivalent Radial Load equations for tapered roller
bearings. TABLE 2
Two Row Mounting - Identical Series
R
R A
R B
(F a
) A
F a
The general AFBMA equation for the equivalent radial
load
Bearing
e e
is:
F r F r
Config.
P = X F r
+ Y YF a
X Y (31)
F a
Single 1.00 0.00 0.40 Y
where P = Equivalent radial load
2
Double 1.00 Y 1
0.67 Y 2
F r
= Applied radial load
Values for e, Y 1
, and Y 2
are listed in the tapered roller
bearing dimension F a
= Applied tables. thrust load
In the calculation
X = Radial
of the
load
equivalent
factor
radial load for
a tapered roller bearing, the algebraic sum of all
external thrust Y = Thrust loads load and factor the thrust reactions of
the bearings must be considered. All factors are
automatically In the calculation included of the in equivalent the Equivalent radial Radial load Load for a
formulas tapered bearing, shown in the Table algebraic 3 through sum of 5. all Note, external when thrust the
calculated loads and the Equivalent thrust reactions Radial of Load the bearings is less than must the be
applied considered. radial All load, factors the are radial automatically load alone included is used in the to
estimate Equivalent the Radial bearing Load life. formulas shown in Table II. Note,
when the calculated Equivalent Radial Load is less than
the applied radial load, the radial load alone is used to
estimate the bearing life.
A
Thrust
Condition
R
Fa 0.
6
A
Y
Fa 0 6
A
Y
R
B
Equivalent
Radial Load
P
2 0.83 Y F
A A a A
A
R
P
2 0.83 Y F
B
-
A aA
. R
A A aA
A
TABLE 4
R
P 0.4R Y F
P 0
Two Row Mounting - Dissimilar Series
B
R A
R B
(F a
) A
TABLE II
Equivalent EQUIVALENT Radial RADIAL Load LOAD Formulas FORMULAS
SINGLE ROW MOUNTING
Single Row Mounting
A
B
TABLE 5
0.47R
KA
0.5R
Y
A
0.47R
KA
0.5R
Y
A
A
R A
Thrust
Condition
Thrust
Condition
A
0.47RB
F
A
A
A
a A
KB
0.5R
B
F
Y
B
a A
0.47RB
Fa
KB
0.5R
B
F
Y
B
A
a A
(F a
) A
R B
TABLE 3 Equivalent
Radial
Equivalent
Load
Radial Load
00.50R . 47R
B
PA 0.
40RA KY A
Fa
YK
B
0 . 5.
R
BB
P 0.
4 R
Y
F
B
PA B
RB
AA AA
PB
RB
PA
RA
00.50R P
47 B
A
B
0R
. 40 A RB KY B
0 . 5
PB 0.
4 R
BB
Y
BB
Thrust
Condition
A
R
+ Fa 0.
6
A
Y A
Y B
A
Y
Y
A
B
PB
-
Y
+ A
Y
B
R
F
a 0 6
PA 0.
4R Y
A Fa A
A
YA
PB
0
(F a ) A
a aAA
Y
BB
. R
A
– (FF
a ) A
KY
. R A
AA–
F
a a
AA
Y
AA
. P
Equivalent
Radial Load
Where: where
R = Total radial load—lbs.
R A
= Radial load, brg. A—lbs.
R B
= Radial load, brg. B—lbs.
(F a
) A
= External thrust on brg. A*—lbs.
KY A = Factor Axial load K brg. factor A brg. A
KY B = Factor Axial load K brg. factor B brg. B
P A
= Equivalent radial load, brg. A—lbs.
P B
= Equivalent radial load, brg. B—lbs.
Y
K K R 1.67 Y F
B
Y A a A
K K R 1.67 Y F
a A
* When there are no external thrust loads F a
= 0 in equations above.
13