Disclosed are a robot dual-joint unit as well as a legged robot and a cooperative robot arm using same. The robot dual-joint unit comprises a first joint consisting of a first motor and reducer assembly (1), and a second joint consisting of a second motor assembly (2) and a second reducer (6); a first output connecting rod (3) is fixed on the output shaft of the first motor and reducer assembly; the second speed reducer is arranged in the first output connecting rod; and the second motor assembly drives the second reducer via a transmission rod (9). The fixed end of the second motor assembly is fastened together with the fixed end of the first motor and reducer assembly, which is different to the conventional robot joint structure with the fixed end of a second motor being fastened to the output end of the first motor and reducer assembly, thus making the output inertia of two output shafts of the robot dual-joint unit very small and leaving out the power cable which penetrates into the second motor assembly of the second joint.
ROBOT DUAL-JOINT UNIT AS WELL AS LEGGED ROBOT AND COOPERATIVE ROBOT ARM USING SAME