Abstract: A housing of plastics material for a centrifugal blower for automotive HVAC systems is provided. The housing has a base half shell and a cover half shell joined to each other, and a sound absorption structure having a chamber side panel fitted into a seat formed in the base half shell and facing an impeller chamber, and an outlet side panel fitted into a seat formed in the cover half shell and facing an air outlet duct.

Abstract: A fan assembly includes a shroud having a through opening, around which the shroud defines an air conveying ring, a motor-fan assembly which includes an axial fan rotatable with respect to the support about an axis of rotation, and a noise-reducing annular structure, having a plurality of projections which are arranged in succession in a circumferential direction and extend radially towards the axis of rotation of the fan, each projection having a face which is directed towards the axis of rotation and is substantially parallel thereto, and a plurality of portions radially recessed towards the air conveying ring.

Abstract: A fan assembly comprising, a shroud having a through opening, around which the shroud defines an air conveying ring, a motor-fan assembly which includes an axial fan rotatable with respect to the support about an axis of rotation, and a noise-reducing annular structure, having a plurality of projections which are arranged in succession in a circumferential direction and extend radially towards the axis of rotation of the fan, each projection having a face which is directed towards the axis of rotation and is substantially parallel thereto, and a plurality of portions radially recessed towards the air conveying ring. Each of the recessed portions has a face which is directed towards the axis of rotation of the fan and the profile of which in the axial direction is generally curvilinear and not parallel to the axis of rotation.

Abstract: A fan assembly comprising, a shroud having a through opening, around which the shroud defines an air conveying ring, a motor-fan assembly which includes an axial fan rotatable with respect to the support about an axis of rotation, and a noise-reducing annular structure, having a plurality of projections which are arranged in succession in a circumferential direction and extend radially towards the axis of rotation of the fan, each projection having a face which is directed towards the axis of rotation and is substantially parallel thereto, and a plurality of portions radially recessed towards the air conveying ring. Each of the recessed portions has a face which is directed towards the axis of rotation of the fan and the profile of which in the axial direction is generally curvilinear and not parallel to the axis of rotation.