Planetary reducer and assembling method of gear ring of planetary reducer

The planetary reducer and the gear ring assembling method are used for assembling the gear ring and a shell into a whole, an opening is formed in the end of the shell, and the inner diameter of the opening is matched with the outer diameter of an inner gear ring; a plurality of first-order splines and a plurality of second-order splines are arranged on the peripheral wall of the inner gear ring in a protruding mode and are arranged in the axial direction of the inner gear ring, and the outer diameter of the second-order splines is larger than that of the first-order splines. A first-order chip containing groove matched with the first-order spline and a second-order chip containing groove matched with the first-order spline are formed in the peripheral wall of the inner gear ring. When the gear ring and the shell are assembled, the first-order spline and the second-order spline cut the inner wall of the opening of the shell, so that the first-order spline and the second-order spline are embedded into the shell