US Patent 10294955 Fan apparatus

A fan apparatus (e.g., for a vehicle radiator) includes a hub and plural fan blades. The hub has an annular hub body with an outer peripheral wall, an interior, and a central axis. The hub body defines plural blade retention apertures spaced apart from one another around the hub body and extending radially outward from the interior through to the outer peripheral wall. The fan apparatus also includes plural fan blades respectively removably disposed in the plural blade retention apertures. The fan blades and the blade retention apertures are complimentary in shape for the fan blades to be retained by the hub solely by centrifugal force when the hub is rotated for operation of the fan apparatus.