Patent ID: 8656800

Claim:
A harmonic drive using profile shifted gears, comprising: a plurality of internal gears; a band-typed flexible gear provided with a plurality of teeth engaged with each of the internal gears on its outer circumferential surface, the flexible gear having a pitch circumference length shorter than that of each of the internal gears; and a wave generating part disposed on an inner side of said flexible gear, the wave generating part generating a plurality of harmonic motions by deforming said flexible gear as the wave generating part rotates; wherein said flexible gear is formed integrally to engage with said plurality of internal gears so that the plurality of harmonic motions are overlapped, and wherein the plurality of teeth of the flexible gear comprise at least first external teeth formed of profile shifted teeth configured to engage with a first internal gear and second external teeth formed of standard teeth configured to engage with a second internal gear, the first external teeth and the second external teeth having the same pitch circumference length.