Patent ID: 8568263

Claim:
A gear transmission comprising: an external gear; an internal gear that is eccentrically rotatable relative to the external gear while meshing with the external gear; at least one crankshaft configured to eccentrically rotate the internal gear and passing through the internal gear; and a motor comprising a motor body and an output shaft that is rotatable relative to the motor body; wherein at least one first recess is formed on an outer peripheral side of the internal gear, the at least one first recess being disposed radially inward of an imaginary circle that intersects a radially-outermost portion of the outer peripheral side of the internal gear, at least a portion of the motor body is disposed within the first recess, the at least one crankshaft and the output shaft of the motor extend in parallel to each other, and the gear transmission has an axial length in an axial direction thereof, and the motor has an axial length in the axial direction that is less than or equal to the axial length of the gear transmission, such that the motor is axially disposed entirely within the axial length of the gear transmission.