Sealing type worm gear speed reducer

The utility model relates to a sealed worm gear speed reducer which comprises a box body, a motor arranged outside the box body, a worm and an output shaft which are arranged in the box body, a base, a bearing and an oil seal piece, the box body is provided with a top cover and a rear machine cover, the rear machine cover is connected with the motor for controlling the worm to rotate, the base is connected inside the box body, and the bearing is connected with the oil seal piece. The two ends of the base are rotationally connected with worms through bearings, the box body is rotationally connected with an output shaft in meshed connection with the worms through bearings, and the two ends of the output shaft are provided with oil seal pieces connected with the box body. The worm is installed in the box body through the base, compared with a traditional worm gear speed reducer structure, a shaft hole, located at the position of the worm, of the box body is omitted, a sealed containing cavity is formed in the bo