Electric fan

Abstract

An electric fan, for cooling a heat exchanger of a motor vehicle, has an electric motor including a rotor and a stator, and an axial impeller including a central hub from which a plurality of blades extends. The hub is connected to the rotor at a number of connecting points. At each connecting point, the hub of the impeller is connected to the rotor by means of a respective connecting device including a resilient vibration damper.

1 . Electric fan, for a heat exchanger of a motor vehicle, comprising:
 an electric motor including a rotor and a stator; and   an axial impeller including a central hub from which a plurality of blades extends, the hub being connected to the rotor of said motor at one or more connecting points or areas,   wherein at these one or more connecting points or areas, the hub of the impeller is connected to the rotor of the electric motor by means of a respective connecting device including a resilient vibration damper.   
     
     
         2 . The electric fan of  claim 1 , wherein the hub of the impeller has a substantially bowl-like shape, with an end wall connected to an annular lateral wall which is at least approximately cylindrical, and wherein the rotor of the electric motor has a crown which extends inside the hub of the impeller, near the end wall of said hub, to which it is connected by means of a plurality of said connecting devices including respective resilient vibration dampers. 
     
     
         3 . The electric fan of  claim 1 , wherein each of these one or more connecting devices comprises an annular damping member of resilient material, positioned in a through opening of the hub and penetrated by a fastening member for fastening the hub to the rotor of the motor. 
     
     
         4 . The electric fan of  claim 3 , wherein each damping member is of elastomeric material. 
     
     
         5 . The electric fan of  claim 3 , wherein a tubular element of essentially rigid material, is interposed between the damping member and the corresponding fastening member. 
     
     
         6 . The electric fan of  claim 5 , wherein the tubular element is of a metallic material. 
     
     
         7 . The electric fan of  claim 5 , wherein said fastening member is a screw or bolt having an end head, and said rigid tubular element has at one end a flange-like formation interposed between the head of the corresponding screw or bolt and said damping member. 
     
     
         8 . The electric fan of  claim 3 , wherein the or each resilient vibration damper is in the form of a cylindrical ring, and has an outer peripheral groove that engages with an edge of said through opening of the hub of the impeller.