Harmonic Drive FHA Series, Руководство пользователя

Страница: 24 / 51

• Calculating average loads: average radial
and axial loads, average output speed
When the radial and/or axial loads vary during motion, calculate and verify
the life of the cross roller bearing converting the loads to their average values.
• Average radial load: Fr av
10/3
n
1
t
1
|
Fr
1
|
10/3
+n
2
t
2
|
Fr
2
|
10/3
...n
n
t
n
|
Frn
10/3
Fa av = (2)
√
n
1
t
1
+ n
2
t
2
+ ... +nn tn
Note: "Fr
1
" is the maximum radial load in "t
1
" range,
and "Fr
3
" is the maximum radial load in "t
3
" range.
• Average axial load: Fa av
10/3
n
1
t
1
|
Fa
1
|
10/3
+n
2
t
2
|
Fa
2
|
10/3
...n
n
t
n
|
Fa
n
|
10/3
Fa av = (3)
√
n
1
t
1
+ n
2
t
2
+ ... +n
n
t
n
Note: "Fa
1
" is the maximum radial load in "t
1
" range,
and "Fa
3
" is the maximum radial load in "t
3
" range.
• Average output speed: N av
10/3
n
1
t
1
+n
2
t
2
+...n
n
t
n
(4)
N av =
t
1
+ t
2
+ ... + t
n
• Calculating radial load factor and axial load factor
Both load factors are different with average loads as follows:
•
When the right formula is satisfied,
Fa av
Fr av + 2(Fr av ( L r+ R ) + Fa av
.La ) /dp
<1.5 (5)
X=1.0, and Y=0.45
•
When the formula below is satisfied,
Fa av
Fr av + 2(Fr av ( Lr + R ) + Fa av
.La ) /dp
>1.5 (5’)
X=0.67, and Y=0.67
Where, the variables of the formula are:
M max : Maximum torsional moment in N•m(kgf•m); obtained by the formula (1)
Fr max : Maximum radial load in N(kgf); See Fig.1.
Fa max : Maximum axial load in N(kgf); See Fig.1.
Lr, La: Loading point in mm; See Fig.1.
R: Offset; See Fig.1 and Table 1.
dp: Circular pitch of roller: See Fig.1 and Table 1.
Chapter 2 Guidelines for sizing
Time
Time
Time
Fr
1
Fr
2
Fa
1
Fa
2
Fr
3
Fa
3
t
1
t
2
t
3
n
1
n
2
n
3
– Axial load +
– Axial load +
– Axial load +
21