Patent ID: 7922466

Claim:
A radial fan having an impeller and a housing assembly, the impeller having a periphery, a cover side, and an underside, the housing assembly comprising a cover, and at least the cover comprising a light-metal casting material, wherein, in order to form a cage which encloses the impeller, a cover-side cage plate is provided on the cover side and an underside cage plate is provided on the underside of the impeller, the cover-side and underside cage plates being held together around the periphery of the impeller by connectors, at least the connectors and the cover-side cage plate comprising a hard and tough material, wherein further the connectors are formed with steel collars or are provided with steel nuts in order to support the cover-side and underside cage plates at a respective rear portion of each of the cover-side and underside cage plates, wherein a diffuser part is disposed beneath the cover, and the cover-side cage plate is disposed between the cover and the diffuser part, wherein the impeller has blades, wherein in a radial direction the blades have a total range of different heights along a longitudinal axis of the impeller, wherein a gap formed by the cover-side and underside cage plates over a portion of the longitudinal axis of the impeller overlaps only a partial range of the total range of heights of the blades, and wherein the partial range includes at least a height of the blades at their greatest radial extent.