2-3 Verifying and examining load weights
78
1
2
3
4
5
6
7
8
9
10
11
付
S
e
le
c
tion gui
de
line
s
Radial load coefficient and axial load coefficient
Determine the values of radial load coefficient (X) and axial load coefficient (Y) based on the condition
below.
Table 2: Radial load coefficient (X), axial load coefficient (Y)
◆
Formula (5)
Ｘ
Ｙ
5
.
1
La)/dp
Fa
R)
(Lr
2(Fr
Fr
Fa
≤
⋅
+
+
+
av
av
av
av
1
0.45
1.5
La)/dp
Fa
R)
(Lr
2(Fr
Fr
Fa
>
⋅
+
+
+
av
av
av
av
0.67
0.67
Dynamic equivalent radial load
Life of cross roller bearing
Calculate the life of cross roller bearing with the formula (7):
Symbols used in the formulas
Fr
av
Average radial load
N
Refer to the average load.
Fa
av
Average axial load
N
Refer to the average load.
Lr ,La
――――
mm
Refer to Fig.1.
R
Offset amount
mm
Refer to Fig.1 and Table 1.
dp
Pitch circle diameter of a roller
mm
Refer to Fig.1 and Table 1.
◆
Formula (7): Cross roller bearing life
10/3
6
10
B
Pc
fw
C
N
60
10
L
⋅
×
×
=
−
av
Symbols used in the formulas
L
B-10
Life
hour
―
N
av
Average output rotational
speed
r/min
Obtained by formula (4).
C
Basic dynamic rated load
N
Refer to Table 1.
Pc
Dynamic equivalent radial
load
N
Obtained by formula (6).
fw
Load coefficient
－
Refer to Table 3.
◆
Formula (6): Dynamic equivalent radial load
av
av
av
av
Fa
Y
dp
La)
Fa
R)
(Lr
2(Fr
Fr
X
Pc
⋅
+
⋅
+
+
+
⋅
=
Symbols used in the formulas
Pc
Dynamic equivalent radial
load
N
Fr
av
Average radial load
N
Obtained by formula (2).
Fa
av
Average axial load
N
Obtained by formula (3).
dp
Pitch circle diameter of a
roller
mm
Refer to Table 1.
X
Radial load coefficient
－
Refer to Table 2.
Y
Axial load coefficient
－
Refer to Table 2.
Lr
，
La
－
mm
Refer to Fig.1.
R
Offset amount
mm
Refer to Fig.1 and Table 1.
Table 3: Load coefficient
Loaded state
fw
Smooth operation free
from impact/vibration
1 to 1.2
Normal operation
1.2 to 1.5
Operation subject to
impact/vibration
1.5 to 3
