Friction Stir Welding Apparatus and Robot Employing the Apparatus

A method of welding a plurality of work pieces together, the method comprising steps of:

• moving a rotating tool of a stir welding apparatus;
• and
• pressing the rotating tool against the plurality of work pieces at a speed sufficient to soften the work pieces due to frictional heat and weld the work pieces together,
• wherein the stir welding apparatus comprising:
• a rotational shaft extending along an axis of rotation and arranged to operatively support the rotating tool;
• a first rotational drive source operatively coupled to the rotational shaft;
• a rotatable outer shaft surrounding the rotational shaft and fixed against axial movement;
• a second rotational drive source operatively coupled to the outer shaft;
• and
• a bracket having a header, the header arranged to operatively support the rotational shaft, the bracket guided for linear translation along the axis of rotation, and operatively coupled to the outer shaft to permit linear movement of the bracket in response to rotation of the outer shaft, to thereby permit linear movement of the rotational shaft.