Transmission structure of worm and gear speed reducer

The utility model discloses a worm and gear speed reducer transmission structure which comprises a box body, a speed reducing motor, a worm, a worm gear, a worm gear output shaft, an output flange and a thrust bearing, the speed reducing motor is installed on one side of the box body, the worm gear, the worm and the worm gear output shaft are arranged in the box body, the output shaft of the speed reducing motor is connected with the worm, and the worm is meshed with the worm gear. The output flange is connected with a worm gear output shaft, a mounting groove is formed in the face, close to the output flange, of the box body, the thrust bearing comprises a first thrust plate, a second thrust plate and a plurality of rolling bodies, the thrust bearing is arranged in the mounting groove, the first thrust plate abuts against the bottom face of the mounting groove, and the second thrust plate abuts against the output flange. And the plurality of rolling bodies are arranged between the first thrust plate and the