Abstract: The invention relates to a blade assembly 30 for a large dimension axial fan 32 having a rotation axis X. The blade assembly of the invention comprises: a root structure 34 intended to mechanically connect the blade assembly to a hub 36; a blade, wherein at least one portion of the blade has a composite airfoil 46 comprising a fore semi-airfoil 48 and an aft flap 50, wherein: the semi-airfoil is intended to be assembled at a predefined pitch angle ?c with respect to the hub 36 by means of the root structure; the flap 50 is mounted on the blade such that it can be fixed in a position comprised between a maximum deflection position and a minimum deflection position with respect to the pitch angle ?c; and between the fore semi-airfoil and the aft flap a channel 54 is defined suitable for allowing a fluid flow from the face v to the back d of the composite airfoil. The invention further relates to a fan comprising a plurality of blades.

Abstract: A ducted axial fan. The fan includes a rotor rotatable around an axis X and having a plurality of blades, and a duct suitable for defining a circular section channel developing in an axial direction around the rotor. The duct includes an annular seat circumferentially extending around the rotor, and the blade tips are at least partially received in the annular seat of the duct.

Abstract: Today the low noise blades and especially the super low noise blades for large diameter axial fans which are employed in the big cooling machines and cooling plants are so costly and are requiring so many extra costs on the other related equipment, that the noise pollution abatement can increase the whole cooling apparatus cost by up to a 35%. This invention, provides a new technology to make low noise fans able to transform any common blade into a low noise or very low noise at very low cost, preserving the same high efficiency and tip speed, as opposite to all the other low noise blades at actual status of art. As the fans for the big cooling apparatus are generally their main noise source, this invention will offer the opportunity to dramatically reduce the noise pollution produced by big cooling machines and cooling plants.

Abstract: Today the low noise blades and especially the super low noise blades for large diameter axial fans which are employed in the big cooling machines and cooling plants are so costly and are requiring so many extra costs on the other related equipment, that the noise pollution abatement can increase the whole cooling apparatus cost by up to a 35%. This invention, provides a new technology to make low noise fans able to transform any common blade into a low noise or very low noise at very low cost, preserving the same high efficiency and tip speed, as opposite to all the other low noise blades at actual status of art. As the fans for the big cooling apparatus are generally their main noise source, this invention will offer the opportunity to dramatically reduce the noise pollution produced by big cooling machines and cooling plants.

Abstract: A ducted axial fan. The fan includes a rotor rotatable around an axis X and having a plurality of blades, and a duct suitable for defining a circular section channel developing in an axial direction around the rotor. The duct includes an annular seat circumferentially extending around the rotor, and the blade tips are at least partially received in the annular seat of the duct.

Abstract: The invention relates to a blade assembly 30 for a large dimension axial fan 32 having a rotation axis X. The blade assembly of the invention comprises: a root structure 34 intended to mechanically connect the blade assembly to a hub 36; a blade, wherein at least one portion of the blade has a composite airfoil 46 comprising a fore semi-airfoil 48 and an aft flap 50, wherein: the semi-airfoil is intended to be assembled at a predefined pitch angle ?c with respect to the hub 36 by means of the root structure; the flap 50 is mounted on the blade such that it can be fixed in a position comprised between a maximum deflection position and a minimum deflection position with respect to the pitch angle ?c; and between the fore semi-airfoil and the aft flap a channel 54 is defined suitable for allowing a fluid flow from the face v to the back d of the composite airfoil. The invention further relates to a fan comprising a plurality of blades.

Abstract: Today the low noise blades and especially the super low noise blades for large diameter axial fans which are employed in the big cooling machines and cooling plants are so costly and are requiring so many extra costs on the other related equipment, that the noise pollution abatement can increase the whole cooling apparatus cost by up to a 35%. This invention, provides a new technology to make low noise fans able to transform any common blade into a low noise or very low noise at very low cost, preserving the same high efficiency and tip speed, as opposite to all the other low noise blades at actual status of art. As the fans for the big cooling apparatus are generally their main noise source, this invention will offer the opportunity to dramatically reduce the noise pollution produced by big cooling machines and cooling plants.

Abstract: The present invention concerns a connecting element for connecting a blade, or airfoil profile, to the hub of an industrial axial fan, a blade system comprising said connecting element, and an industrial axial fan comprising such blade system. The connecting element (1) for connecting a blade (10) to the hub (20) of an industrial axial fan according to the present invention, is realized in a single L-shaped piece comprising a first part (1a) having a substantially straight develop and a second part (1b) having a substantially straight develop, said first (1a) and second (1b) part being connected by a linking part (1c) presenting a curvature radius, said first (1a) and second (1b) parts lying on substantially perpendicular planes. The connecting element according to the present invention allows to achieve several advantages with respect to the prior art, one of said advantages consisting of its extremely simple shape and manufacturing process, which render the connecting element economically advantageous.

Abstract: A hub-profile connection system for axial fan is disclosed, consisting of a hub to which one or more blades provided with an air displacement profile are connected, wherein one or more blades are attached in a flexible manner to the hub by means of two separate flexible elements, both fixed, reciprocally distinct, separate and overlapped one to the other in the fan axis direction on the hub side, to a fastening block and, on the blade side, to a corresponding fastening block. Compared with the known rigid, hinged and flexible constraint systems, the system of the present invention offers lower static and dynamic loads, as well as construction simplicity, with consequent cost saving and vibration abatement.

Abstract: A hub-profile connection system for axial fan, consisting of a hub to which one or more blades provided with an air displacement profile are fixed, said system comprising two separate and distinct flexible elements both fixed on-hub side, to a fastening block and, on blade side, to a corresponding fastening block. Compared with the rigid constraint systems, the system of the invention offers lower static and dynamic loads, with consequent cost saving and vibration abatement. With respect to hinged constraint systems, there are the advantages of a particular construction simplicity, the possibility of graduating the freedom of movement on the vertical plane as desired and the absence of wear.

Abstract: The present invention relates to an axial fan of the type comprising a hub, a plurality of arms extending radially outwardly from the hub and blade members, each blade member being secured to its respective arm, wherein the arms consist of flexible elements with a bending stiffness such that, in operation, the blade members are inclined at an angle at which the centrifugal forces acting on the blade members neutralize the traction forces acting on same. The load variations and ensuing vibrations are thus substantially reduced, thereby increasing the service life of the fan blades and the drive mechanism.