Looking at the open gyralight, you can see that the bulb frame is attached to a ball joint on the left hand side and a movable slide on the right hand side  The slide rides over a bearing assembly.  Both the ball joint and bearing assembly are attached to the outer case.

The motor, attached to the back of the outer case, is connected to the slide through the motor gearbox and an eccentric shaft.  The slide moves in a reciprocating pattern when the motor is activated.  This in turn causes the right hand side of the frame to reciprocate thus creating a circular or oval movement of the light beam.

With the bulb removed, you can see the motor and gear box, the eccentric connecting shaft and the slide.  Because the motor and bulb frame are not removable as a unit, this gyralight is difficult to inspect and maintain.