Top-mounted gear transmission structure of concrete mixing truck

The utility model relates to a top-mounted gear transmission structure of a concrete mixing truck, which comprises a connecting shaft arranged at the front inclined head of a mixing drum, a speed reduction driving system and a supporting seat, the connecting shaft is fixedly arranged at the front end of a drum body of the mixing drum, the speed reduction driving system comprises a pinion, a big gear ring and a shell, and the pinion is meshed with the big gear ring; wherein the supporting seat is provided with a first mounting part, a second mounting part and a bent part, the shell is hinged tothe first mounting part of the supporting seat, the bent part of the supporting seat is rotatably connected with a fixed seat on the chassis, and the pinion is located on the second mounting part ofthe supporting seat. A speed reducer does not need to be additionally arranged on the mixing drum to reduce the rotating speed and increase the torque; speed reduction is achieved directly through meshing of the small gear and