Abstract: This invention relates to an industrial robot in which a concentric triple shaft is constituted by a first drive shaft (28), a cylindrical, second drive shaft (27) which concentrically encloses the first drive shaft (28), and a cylindrical, third drive shaft (26) which concentrically encloses the second drive shaft (27). There are provided a first box member (65) capable of rotating concentrically with the third drive shaft (26), a second box member (66) which is supported rotatably by the first box member (65) on an axis intersecting the axis of rotation of the first box member (65) perpendicularly or obliquely, and an output member (80b, 100, 105) which is supported rotatably by the second box member (66) on an axis intersecting the axis of rotation of the second box member (66) perpendicularly or obliquely and which is rotated by the first drive shaft (28).

Abstract: An industrial robot includes a plurality of motors provided at an end of a hollow link, torque transmission units provided within said link for transmitting rotational torques of the plurality of motors, and rotary units for a plurality of independent rotational motions in response to each of the motors. The rotary units provided at the other end of the hollow link and are drivingly connected to the torque transmission units.The rotary units comprise a first rotary device having a first box and rotating about an axis of the hollow link, a second rotary device having a second box and rotating about a rotary axis which obliquely intersects with a rotary axis of the first device, and a third rotary device having an output shaft and rotating about a rotary axis which intersects obliquely with the rotary axis of the second rotary device.