Joint structure for industrial robot

The utility model discloses a joint structure for an industrial robot. The joint structure comprises an elbow shell, an electric motor, a straight gear, a hollow big gear, a hollow speed reducer, a small arm and a cable. The electric motor is mounted on the elbow shell. The straight gear is arranged on an output shaft of the electric motor and meshed with the hollow big gear supported on the elbow shell through a bearing. The hollow big gear is meshed with a planet gear of the hollow speed reducer. The small arm is mounted on an output shaft of the hollow speed reducer which is mounted at the other end of the elbow shell. The hollow big gear and the hollow speed reducer are provided with concentric center holes. The cable penetrates through the concentric center holes through the reverse side of the elbow shell and reaches the small arm, and is fixed at a penetrating end of the elbow shell and the small arm through a line card. The cable of the joint structure for the industrial robot can directly penetrate t