High-speed-stage side-mounted rotary driving mechanism with large transmission ratio and small return difference

The utility model discloses a high-speed-stage side-mounted rotary driving mechanism with a large transmission ratio and a small return difference. Wherein the small tooth-shaped belt wheel is fixedlyconnected to an input motor shaft, and the supporting base box body and the large tooth-shaped belt wheel are fixed to the bottom of a precision speed reducer. An input shaft of the speed reducer penetrates out of the middle of the bottom of the supporting seat box body; an intermediate shaft is supported on one side of the speed reducer input shaft in the supporting seat box body through an upper bearing and a lower bearing which are respectively arranged on the upper side wall and the lower side wall of the supporting seat box body; the intermediate shaft penetrates out of the lower side wall of the supporting seat box body; a driving gear is arranged on the middle shaft in the supporting base box body in a penetrating mode, a driven gear is arranged on the speed reducer input shaft inthe supporting base box bo