Abstract: The impeller wheel is rotatably supported about a central axis and has a hub on which vanes are arranged. The vane has across its radial length at least similar profiled sections, viewed in cylindrical section through the vane. The radial outermost profiled section which is positioned on a cylindrical enveloping surface of the impeller wheel has a greater displacement relative to the neighboring profiled section than this neighboring profiled section to its neighboring profiled section. The impeller wheel can also be provided on the radial outer edge with at least one projecting flow element whose axial height has a maximum in the area of the leading edge and of the trailing edge of the vane. The impeller wheels, while having a simple constructive configuration, provide a great noise reduction in operation of the ventilator.

Abstract: The impeller wheel is rotatably supported about a central axis and has a hub on which vanes are arranged. The vane has across its radial length at least similar profiled sections, viewed in cylindrical section through the vane. The radial outermost profiled section which is positioned on a cylindrical enveloping surface of the impeller wheel has a greater displacement relative to the neighboring profiled section than this neighboring profiled section to its neighboring profiled section. The impeller wheel can also be provided on the radial outer edge with at least one projecting flow element whose axial height has a maximum in the area of the leading edge and of the trailing edge of the vane. The impeller wheels, while having a simple constructive configuration, provide a great noise reduction in operation of the ventilator.

Abstract: The invention provides a ventilator blade (1) with a loading edge (2) curved in the shape of an S in the blade sheet plane; and an outside edge (4) that is shorter than the leading edge, in which the center of the outside edge (4) lies in the vicinity of the rotation axis (x) of the ventilator blade (1), as well as a ventilator (9) that uses at least one ventilator blade (1) according to the invention.

Abstract: An axial fan with reversible flow direction comprises a rotor (11), which is driven by a variable speed-controlled driving motor (14) and is provided with adjustable rotor blades (13) fitted around a rotational axis. The rotor (11) is preceded by an inlet stator (15) and followed by a downstream stator (16), which are each provided with guide vanes (17, 18). The guide vanes (17, 18) of the inlet stator (15) and the downstream stator (16) are designed so as to be mirror-symmetrical to the radial center plane of the rotor (11) and may be adjusted at an angle to the direction of flow in such a way that—when the flow direction is reversed—the inlet stator (15) takes on the function of a downstream stator and the downstream stator (16) takes on the function of an inlet stator.