Transmission mechanism and wheel-side electric driving system

The invention relates to a transmission mechanism which comprises a first gear shaft, a second gear shaft, a first-stage planetary mechanism and a second-stage planetary mechanism, the first gear shaft is in transmission connection with the second gear shaft, the second gear shaft is in transmission connection with the first-stage planetary mechanism, and the first-stage planetary mechanism is in transmission connection with the second-stage planetary mechanism. The wheel edge electric drive system comprises a motor, a transmission mechanism, a fixed shell and a brake unit, the motor is connected to the transmission mechanism, the transmission mechanism is installed in the fixed shell, and the brake unit is installed on the transmission mechanism. Through the fixed shaft gear pairs on the two gear shafts, the input rotating speed range is wider, flexible adjustment can be achieved according to the speed ratio requirement, larger torque can be transmitted under the condition that the space is limited, the stru