Toothed planet-gear speed reducer

The utility model relates to a toothed planet-gear speed reducer whose driving end housing 4 is fixedly connected with a driven end housing 11 by a screw bolt. An annular gear A is fixed in the driving housing 4 and an output shaft 13 with an annular gear B is installed in the driven end housing 11 through a bearing 10. One end of an eccentric shaft 9 is fixed in the driving end housing 4 through a bearing 2 and the other end of the eccentric shaft is fixed in a bearing block on the left end of the output shaft 13 through a bearing 8. A connected planet wheel c and a connected planet wheel d are installed on the eccentric shaft 9, and the planet wheel c is engaged with the planet wheel d which is engaged with the annular gear b. The numbers of teeth difference of the two pairs of mutually engaged planet wheels and the annular gear are equal and are one to two teeth in general. The utility model has the advantages of large transmission ratio, few parts, compact structure, small size and convenient installation.