Abstract: A robotic device having at least first and second arms joined with an elbow-joint is relatively maintenance-free and is particularly suitable for use in an atmosphere full of vapors from paints or organic solvents. These substances pose considerable operational problems in conventional robotic devices because of the accumulation of dust and solvents, which causes not only degradation in the performance of the robot but requires high maintenance cost. These problems are solved in the present robotic device by housing the driving motor for the second arm within the confines of the cross sectional area of the first arm, and the second arm is coupled through a connector to the output shaft of the driving motor, again within the same confined area. Such a compact design includes side caps providing protection of the feed-through cables and wires, which are routed out of the first shaft inner space to loop around the elbow-joint to enter into the second shaft inner space.

Abstract: An industrial robot which can be used as a painting robot is mainly constructed by a robot body having a plurality of of motor spaces spaces for housing electric motors. A plurality of guiding passages for flowing in and a plurality of exhaust passages for flowing out a protective gas are formed in the plurality of motor spaces. Also, the robot body has a plurality of temperature sensors for detecting temperatures in the plurality of motor spaces therein. In addition, the robot has gas supplying means for supplying a protective gas into the plurality of passages.

Abstract: A motor-drive industrial robot which can be used as a painting robot is mainly constructed by a direct-drive motor, a fixed portion such as a base, and a movable portion such as a rotary table, an arm etc. The direct-drive motor for driving the movable portion is constructed by a rotor and a stator. Preferably, the stator is attached to the fixed portion, while the rotor is attached to the movable portion. In order to avoid the generation of sparks in the flammable atmosphere, this robot is designed as the explosion-proof construction, so that the protective gas ie enclosed within the direct-drive motor. This protective gas is supplied into an annular space formed between the rotor and stator via a through hole formed through the stator or rotor. In addition, this annular space is sealed such that the protective gas is not leaked from the direct-drive motor.