Industrial robot

Claim 1

An industrial robot comprising a trunk means mounted for vertical and rotational movement on a stationary base; a pair of slide sleeves fixed on said trunk means; first and second arm members mounted within said slide sleeves for rotational and translational movement therein, the outer ends of said arm members being extensible from and retractable into a side of said trunk means through said slide sleeves; a robot wrist mechanism attached to said outer ends of said arm members, said robot wrist being rotatable about a first axis and swingable about a second axis perpendicular to said first axis; a mounting compartment positioned on said trunk means at a side opposite to the side from which said arm means extend; first and second electric motor means fixedly mounted on said trunk means within said mounting compartment; first and second ball spline shafts driven, respectively, by said first and second electric motor means and connected, respectively, with said first and second arm members for imparting rotational movement thereto; mechanical reduction means comprising a pair of harmonic drives connected between said first and second arm members and said robot wrist mechanism for converting said rotational movement of said first and second arm members into rotational and swinging motion of said robot wrist mechanism at predetermined reduction ratios, respectively; and third electric motor means fixedly mounted on said trunk means within said mounting compartment, said third electric motor means being connected through ball screw shaft means to both of said arm members for imparting reversible translatory motion thereto.