Intelitek SCORA-ER 14 - Page 31

As in all gears, the gear ratio of the Harmonic Drive is the ratio of the input speed
to the output speed. If the number of teeth on the flexspline is N
f
, then for every
revolution of the input shaft, the output shaft rotates by 2/N
f
of a revolution (that
is, two teeth out of N
f
teeth). Hence:
HD gear ratio =
1



2
N
f



=
N
f
2
The Harmonic Drive gear ratio for axis 1 and axis 2 of the SCORA-ER 14 is 160:1
Figure 6-10: Operation of the Harmonic Drive
Figure 6-9: Operation of the Harmonic Drive
User’s Manual 6 - 7 SCORA-ER 14
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