Dual-gear transmission device

A dual-gear transmission device comprises a first internal tooth gear, a second internal tooth gear, a harmonic generator and an external tooth gear. First internal teeth are arranged on the first internal tooth gear. Second internal teeth are arranged on the second internal tooth gear. A cylinder is arranged on the external tooth gear. First external teeth and second external teeth are arranged on the outer circumferential face of the cylinder. The first external teeth are meshed with the first internal teeth. The second external teeth are meshed with the second internal teeth. The number of the first external teeth is different from the number of the second external teeth. The number of the first internal teeth and the number of the second internal teeth are different from the number of the first external teeth and the number of the second external teeth. The number of the first internal teeth is larger than that of the first external teeth. The number of the second internal teeth is smaller than that of the second external teeth. The first internal tooth gear is fixed as the stationary side internal tooth gear. The second internal tooth gear is the driving side internal tooth gear for outputting rotation. The dual-gear transmission device is simple in structure, convenient to install and high in set speed ratio freedom degree, enlarges the application range, can easily achieve the low speed ratio, and meets the requirement for the low speed ratio.