Image Number 6 for United States Patent #6477916.
A balance weight has first and second margins at right angles to one another with the second margin larger than the first margin. A balance weight groove in a rotor has outer and inner wall portions, with the outer wall portions spaced a distance less than the spacing between the inner wall portions. The balance weight has a central threaded opening receiving a screw and a driving slot in the upper face of the weight. An insertion tool is threaded to the balance weight to insert the balance weight through a turbomachinery access opening into the groove. The tool is rotated to locate the second margins below the outer wall portions of the groove. By inserting a driving tool through the insertion tool, the screw is rotated to lock the balance weight to the rotor and in the groove. Upon removal of the insertion and driving tools, a staking tool is inserted through turbine access opening to stake the balance weight and rotor and the screw and balance weight.