Patent attributes
A reduction gear transmission capable of realizing a large reduction ratio while preventing both an increase in its diameter and a decrease in the diameter of its through hole, including: a motor gear; an intermediate shaft; a first and second gear; an input shaft; and an external and internal gear. The first and second gears are fixed to the intermediate shaft. The first gear meshes with the motor gear. The input shaft causes an eccentric rotation member to rotate eccentrically with the rotation of the input gear, which meshes with the second gear. The external gear engages the eccentric rotation member, revolving orbitally around an axis line of the input shaft. The internal gear meshes with the external gear, each having a different number of teeth. The motor gear and first gear mesh at a position offset from a straight line formed by connecting an axis line of the intermediate shaft and of the input shaft.
