Balanced turbine rotor and method for making the same

Claim 1

A balanced turbine rotor comprising: a cylindrical member having a pair of opposed end shafts and an enlarged central portion, the enlarged central portion having first and second end faces; a circular groove in at least one of said end faces concentric with the end shafts; and expandable weight assemblies engageable within said circular groove, such that said weight assemblies are insertable into said groove in a direction parallel to the axis of the end shafts and expandable therein to secure the same in a predetermined location about the end face; said expandable weight assemblies comprising an arcuate body member having a rear wall, side walls, top and bottom arcuate walls and a front wall, with a threaded bore formed from the front to the rear wall, terminating at a spaced location from the rear wall, and a slot formed in each side wall extending from the side wall outer surface to said threaded bore forming upper and lower deformable sections; and an expander screw threadedly engageable within said threaded bore arranged to spread said upper and lower deformable sections apart to secure said body in said circular groove, wherein a radially inwardly extending lip is provided, adjacent said face, which lip extends radially into said groove, and the bottom wall of said body has a recess therein at the edge of a said arcuate wall, with said lip seated in said recess when said upper and lower deformable sections of the body are spread apart, wherein the radially extending lip is radially spaced from the bottom arcuate wall of the body member.