PLANETARY GEAR MECHANISM

PROBLEM TO BE SOLVED: To provide a planetary gear mechanism which attains miniaturization at low costs. SOLUTION: A planetary gear mechanism includes: a housing H; an input shaft 2 which has an eccentric section 22 centered on an eccentric shaft which is eccentric to an input/output axis and which is supported rotatably around the input/output axis to the housing H; a rocking surface plate 3 which eccentrically rocks through the eccentric section 22 and whose rotation to the housing H is restricted; and an output shaft 7, on which an internally toothed gear 6, which is internally meshed with an externally toothed gear formed on the rocking surface plate 3, is mounted and which is provided rotatably around the input/output axis to the housing H. The circumferential position, at which the externally toothed gear and the internally toothed gear 6 mesh with each other, changes as the input shaft 2 rotates, and the rotation of the input shaft 2 is reduced in speed and extracted to the output shaft 7. The engagement of a first pin, which protrudes from the rocking surface plate 3, with an insertion hole H1 formed in the housing H restricts the rotation of the rocking surface plate 3. COPYRIGHT: (C)2011,JPO&INPIT