To flucture first and second robot arms freely, and to make a vertical multijoint indutrial robot small in size by suppressing increase of the rotary moment around a horizontal shaft generated by the variation of posture.
Servomotors Mw and Mu, and reduction gears Gw and Gu to flucture the first and the second robot arms 4 and 2 are all provided to a base 3 side. And by composing a transmission device in order to drive the second robot arm 2, by a timing belt 7 instead of a parallel link or a driving shaft, the total weight of the first and the second robot arms 4 and 2 is reduced, and the variation of the rotary moment around a W shaft which is generated by the influence of the fluctuation of the first robot arm 4 and the gravity is suppressed. Since there is no link mechanism, the operations of the first and the second robot arms 4 and 2 are made free, and the whole body of the device is made in a small size.
OKADA TAKESHI
UCHIDA HIROSHI
