Speed reducer with auxiliary air cooling function

The utility model belongs to the technical field of speed reducers, and particularly relates to a speed reducer with an auxiliary air cooling function, which comprises a machine body assembly and a heat dissipation assembly, the machine body assembly comprises a machine frame, a machine box installed on the side of the machine frame, a sleeve fixed in the machine box, a driving shaft assembled in the sleeve, a gear head arranged at the inner side end of the driving shaft, and a transmission gear connected to the gear head in a meshed mode. The shaft sleeve is mounted on the rack; the transmission shaft is fixed in the middle of the transmission gear and assembled in the shaft sleeve; the heat dissipation assembly comprises a heat dissipation fan which is installed on the driving shaft and used for heat dissipation. The cooling fan and the driving shaft rotate synchronously, so that outside airflow penetrates through the cooling opening and the first cooling holes to enter the inner cavity and then carries hea