The invention relates to a planetary-
harmonic composite gear
reducer, which relates to a
reducer, and aims at the problems that the prior cup-shaped
harmonic reducer has small
reduction ratio, large axial size, large volume, large
mass and the like. A sun gear is engaged with at least two planetary gear shafts and is arranged in an elliptical internal gear ring of an elliptical
cam, the at least two planetary gear shafts are engaged with the elliptical internal gear ring of the elliptical
cam to form a primary planetary reduction
gear train, the elliptical
cam is arranged in a flexible
ball bearing, the primary planetary reduction
gear train and the flexible
ball bearing form a wave generator, the flexible
ball bearing is arranged in a flexible gear, the flexible gear is arranged in a rigid internal gear ring and is engaged with the rigid internal gear ring under the action of the wave generator, and a planetary gear shaft arranged in a shaft hole of a tie bar is provided with a rolling bearing. The reducer has the advantages of large
reduction ratio, small axial size, small volume, light
mass and the like, and is particularly suitable to be applied in the fields such as
aviation and space detectors, various instruments and meters, and driving units of precision robots and the like.