US Patent 10989224 Rotor with balancing features and balancing method

A rotor for a fluid machine includes a wheel that is supported for rotation about an axis of rotation. The wheel includes a back wall with an outer rim edge. The rotor also includes a plurality of blades that are attached to the back wall and that are spaced apart about the axis of rotation. Moreover, the rotor includes an inter-blade area on the back wall between neighboring ones of the plurality of blades. Furthermore, the rotor includes a balancing feature that is included in the inter-blade area on the back wall. The balancing feature intersects and defines part of the outer rim edge.