An internal cooling fan assembly for use with a claw-pole segment of a rotor assembly is provided that maximizes air flow while providing a reduced sound signature. The fan assembly includes a base portion that contacts the claw-pole segment when the fan assembly is mounted to the claw-pole segment. The fan assembly also includes a number of blades extending from the base portion such that the blades project outward from a plane normal to the rotor. The plurality of blades have a geometry that aligns with roots of the claw-pole segment. In addition, a first blade of the number of blades is of a first configuration and a second blade of the number of blades is of a second configuration different from the first configuration.