Harmonic Drive CHA - Output Bearing; Lifetime calculation

691018854 12/2015 V01
For continuous operation
The operating life of the output bearing can be calculated using equation 69.3.
4.3 Output Bearing
4.3.1 Lifetime calculation
For oscillating motion
The operating life at oscillating motion can be calculated using equation 69.1.
Equation 69.1
Equation 69.4
Table 69.5
Table 69.3
Type of bearing B
Cross roller bearing 10/3
Four point bearing 3
At oscillating angles < 5° fretting corrosion may occur due to insufficient
lubrication. In this case please contact our sales engineer for counter-
measures.
Bearing type of selected products see “Output Bearing Ratings“ in the
appropriate product chapter.
Oscillating angle
Illustration 69.2
with:
L
10
[h] = Operating life
n
av
[rpm] = Average output speed
C [N] =
Dynamic load rating,
see table “Output Bearing Ratings“
P
C
[N] = Dynamic equivalent load
f
W
= Operating factor
Average output speed
n
av
=
| n
1
| t
1
+ | n
2
| t
2
+ ... + | n
n
| t
n
t
1
+ t
2
+ ... + t
n
+ t
p
Load conditions f
W
No impact loads or vibrations 1 ...1.2
Normal rotating. normal loads 1.2 ... 1.5
Impact loads and/or vibrations 1.5 ... 3
with:
L
OC
[h] = Operating life for oscillating motion
n
1
[cpm] = Number of oscillations/minute*
C [N] =
Dynamic load rating, see table “Output Bearing“
in the appropriate product chapter
P
C
[N] = Dynamic equivalent load
ϕ [Degree] = Oscillating angle
f
W
= Operating factor
* one oscillation means 2ϕ
L
OC
=
10
6
60
.
n
1
.
( )
B
180
ϕ
.
C
f
w
.
P
C
L
10
=
10
6
60
.
n
av
.
( )
B
C
f
w
.
P
C