US Patent 10502230 Integrally bladed rotor having double fillet

An integrally bladed rotor according to an example of the present disclosure includes a hub, and a plurality of rotor airfoils integrally formed with the hub, and extending radially outward from an outer platform of the hub. Each rotor airfoil has a main body that extends radially outward from a root to a tip. A first fillet has a first radius that provides a transition from the outer platform of the hub, and a second fillet situated adjacent to and radially outward of the first fillet, that provides a transition between the first fillet and the main body. The second fillet has a second radius that is less than the first radius.