Patent ID: 10309513

Abstract:
An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers, and is flexed into an ellipsoidal shape by a wave generator. When the theoretical values of the radial flexing amounts at major-axis positions of the first and second external teeth flexed into the ellipsoidal shape are expressed by d1=m1n1 and d2=m2n2 (m1 and m2 represent the modules of the first and second external teeth, and n1 and n2 represent positive integers), the radial flexing amounts of the first and second external teeth flexed by the wave generator satisfy d1a=ωd1 and d2a=ωd2, where 1.25≤ω≤3. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different numbers can be suitably flexed to form excellent mating states with respective internally toothed gears.