US Patent 7361092 Balance assembly for coupling first and second rotating members

A flange member is disclosed for a balance assembly that includes a first rotating element coupled to a second rotating element. The flange member includes a main body exhibiting a predetermined imbalance vector when rotated about an axis of rotation. The flange member also includes a plurality of fastener apertures for attaching one of the first and second rotation elements to the main body. Angular spacing between each of the fastener apertures is substantially equal but for one fastener aperture, such that angular spacing is greater to one side of the one fastener aperture, and such that angular spacing is less to another side of the one fastener aperture.