Ventilation system with free fan blade tip at hub

Abstract

A ventilating fan having a fan housing formed to define an interior space, an inlet opening, and an outlet opening spaced apart from the inlet opening. A fan wheel is arranged to lie within the interior space defining an axis of rotation about which the fan wheel is configured to rotate. The fan wheel has a hub, a plurality of fan blades having a hub end secured to the hub and an opposing inlet end configured to be located adjacent to the inlet opening. A plate extending over the fan blade inlet ends.

1 . A ventilation fan comprising
 a fan housing formed to define an interior space, an inlet opening, and an outlet opening spaced apart from the inlet opening;   a fan wheel arranged to lie within the interior space defining an axis of rotation about which the fan wheel is configured to rotate, the fan wheel comprising
 a hub, 
 a plurality of fan blades having a hub end secured to the hub and an opposing inlet end configured to be located adjacent to the inlet opening, and 
 a plate extending over the fan blade inlet ends. 
   
     
     
         2 . The ventilation fan of  claim 1 , further comprising a scroll and the fan wheel located within the scroll. 
     
     
         3 . The ventilation fan of  claim 1 , wherein the plate defines an annulus. 
     
     
         4 . The ventilation fan of  claim 1 , wherein at least one of the fan blades defines an inner edge and an outer edge and the plate has an inner edge aligned with the blade inner edge at the blade inlet end. 
     
     
         5 . The ventilation fan of  claim 1 , wherein at least one of the fan blades defines an inner edge and an outer edge and the plate outer edge is aligned with the blade outer edge at the blade inlet end. 
     
     
         6 . The ventilation fan of  claim 1 , wherein at least one of the fan blades defines an inner edge and an outer edge and the fan blade inner edge is angled with respect to the axis of rotation. 
     
     
         7 . The ventilation fan of  claim 1 , wherein at least one of the fan blades defines an inner edge and an outer edge and the fan blade outer edge is parallel with the axis of rotation. 
     
     
         8 . The ventilation fan of  claim 1 , wherein at least one fan blade extends beyond an outer perimeter of the hub. 
     
     
         9 . The ventilation fan of  claim 1 , wherein the hub end of at least one of the fan blades defines a secured portion secured to the hub and a free portion, which extends radially beyond the hub. 
     
     
         10 . The ventilation fan of  claim 6 , wherein the hub end of the at least one fan blade defines a secured portion secured to the hub and a free portion, which extends radially beyond the hub. 
     
     
         11 . A fan wheel for a ventilation fan, the fan wheel comprising:
 a hub,   a plurality of fan blades having a hub end secured to the hub and an opposing inlet end configured to be located adjacent to an inlet opening of a ventilation fan, and   a plate extending over the fan blade inlet ends.   
     
     
         12 . The fan wheel of  claim 11 , wherein the plate defines an annulus. 
     
     
         13 . The fan wheel of  claim 11 , wherein at least one of the fan blades defines an inner edge and an outer edge and the plate has an inner edge aligned with the blade inner edge at the blade inlet end. 
     
     
         14 . The fan wheel of  claim 11 , wherein at least one of the fan blades defines an inner edge and an outer edge and the plate outer edge is aligned with the blade outer edge at the blade inlet end. 
     
     
         15 . The fan wheel of  claim 11 , wherein at least one of the fan blades defines an inner edge and an outer edge and the fan blade inner edge is angled with respect to the axis of rotation. 
     
     
         16 . The fan wheel of  claim 11 , wherein at least one of the fan blades defines an inner edge and an outer edge and the fan blade outer edge is parallel with the axis of rotation. 
     
     
         17 . The fan wheel of  claim 11 , wherein at least one fan blade extends beyond an outer perimeter of the hub. 
     
     
         18 . The ventilation fan of  claim 11 , wherein the hub end of at least one of the fan blades defines a secured portion secured to the hub and a free portion, which extends radially beyond the hub. 
     
     
         19 . The ventilation fan of  claim 15 , wherein the hub end of the at least one fan blade defines a secured portion secured to the hub and a free portion, which extends radially beyond the hub. 
     
     
         20 . A fan wheel comprising:
 a hub,   a plurality of fan blades having a hub end secured to the hub and an opposing inlet end configured to be located adjacent to an inlet opening of a ventilation fan, and   a plate extending over the fan blade inlet ends.