Life Of The Wave Generator Bearing - Harmonic Drive HFUS-2A Series Engineering Data

4.1.2 Life of the Wave Generator Bearing

Given that the Harmonic Drive® Gear is rated to provide infinite fatigue life for the Flexspline, the life expectancy is based on
the average life of the Wave Generator bearing. The rated torque at the rated speed given in the rating table is based on the
mean L bearing life.
50
The life expectancy of a component set or an unit operating at an input speed n (rpm) and output torque T (Nm) may be
estimated from equation 21.2.
Table 21.1
Harmonic Drive® series
CobaltLine, CSG, SHG
HFUC, HFUS, CSD, CPU, CSF, SHD
PMG gearbox
Equation 21.2
Equation 21.3
n = Rated input speed [rpm]
N
n = Average input speed [rpm] (equation 19.5)
in av
T = Rated output torque at rated speed [Nm]
N
T = Average output torque [Nm] (equation 19.2)
av
L = See table 21.1
n
1019658 11/2014
n
T
( )
3
N
L = L N
n
50
n
T
in av
av
–
1
≈
L L
•
50
10 5
L
n
50000
35000
15000
[h]
21