Gearbox power transmission mechanism

The invention discloses a gearbox power transmission mechanism, and relates to the technical field of gearbox transmission, the gearbox power transmission mechanism comprises a gearbox body, the bottom of the gearbox body is fixedly provided with a lubrication box, the interior of the lubrication box is hollow, the top of the gearbox body is provided with a gear lever, the other end of the gear lever extends downwards, and the gear lever is arranged in the lubrication box. A connecting assembly is fixedly installed on one side of the outer wall of the gearbox body, a power output shaft is fixedly installed on the connecting assembly, and a middle shaft is fixedly installed on the connecting assembly. A cooling and lubricating assembly is arranged in the gearbox body, a triggering air bag is installed on the top of the inner wall of the gearbox body, a gear shifting fork drives a low rod to trigger the air bag during gear shifting, and meanwhile the air bag transmits a signal to a lubricating part so that a hi