Low-noise blower

Abstract

A low-noise blower that can provide a smooth transition of fluid flow and reduce audible noise, which can disrupt a patient's rest and cause fatigue to patients and caregivers, the blower having an impeller and a housing, the impeller with an impeller plate and a plurality of blades each attached to the impeller plate, and the housing with an impeller cavity and a collector, where a slot with inclined surfaces extends between the impeller cavity and the collector.

What is claimed is: 
     
         1 . A blower comprising:
 an impeller having an impeller plate and a plurality of blades attached to the impeller plate, wherein the impeller plate comprises a top surface, and the plurality of blades comprise a top surface; and   a housing comprising a top housing portion and a bottom housing portion, the top housing portion having a slot upper edge with an inclined surface, and the bottom housing portion having a slot lower edge with an inclined surface;   wherein the top and bottom housing portions are coupled together to form an impeller cavity, a collector surrounding the impeller cavity, and a slot extending between the impeller cavity and the collector such that a distance between the inclined surfaces of the slot upper edge and the slot lower edge increases from the impeller cavity to the collector; and   wherein the impeller is positioned within the cavity with the top surface of the plurality of blades aligned the slot upper edge, and the top surface of the impeller plate aligned with the slot lower edge.   
     
     
         2 . The blower of  claim 1 , wherein each of the slot upper edge and the slot lower edge comprise a radius proximate to the impeller, and wherein the top surface of the plurality of blades is aligned with a peak of the upper edge radius, and the top surface of the impeller plate is aligned with a peak of the lower edge radius. 
     
     
         3 . The blower of  claim 1 , wherein the inclined surfaces are disposed relative to each other at an angle within a range of 10-40 degrees. 
     
     
         4 . The blower of  claim 1 , wherein a gap between the top surface of the plurality of blades, at a tip of the respective blade, and the inside surface of the top housing portion is within a range of 0.005-0.050 inch. 
     
     
         5 . The blower of  claim 1 , wherein the bottom housing portion comprises an inside wall that is proximate to an outside edge of the impeller plate, and a gap between the inside wall and the outside edge is in a range of 0.035-0.110 inch. 
     
     
         6 . The blower of  claim 1 , wherein the bottom housing portion comprises a shelf, and the impeller plate further comprises a bottom surface disposed over a portion of the shelf, and s gap between the bottom surface of the impeller plate and the shelf of the housing is less than or equal to 0.050 inch. 
     
     
         7 . The blower of  claim 1 , wherein the collector is formed as a volute. 
     
     
         8 . The blower of  claim 1 , wherein the top surface of each of the plurality of blades comprises a centerline from a tip of the respective blade to an inlet end of the respective blade, and each of the plurality of blades comprises a width that increases radially outward, from an inlet end toward a leading surface of the respective blade. 
     
     
         9 . The blower of  claim 8 , wherein a maximum width of each blade is at least twice a width of an initial width proximate to the inlet end of the respective blade. 
     
     
         10 . The blower of  claim 1 , further comprising a sound-damping layer disposed on a portion of the housing. 
     
     
         11 . A blower comprising:
 an impeller having an impeller plate and a plurality of blades attached to the impeller plate, wherein the impeller plate comprises a top surface, and the plurality of blades comprise a top surface;   a housing comprising a top housing portion and a bottom housing portion, the top housing portion having a slot upper portion, and the bottom housing portion having a slot lower portion; and   an impeller cavity, a collector surrounding the impeller cavity, and a slot formed between the top and bottom housing portions, wherein the slot has a first end adjacent the impeller cavity, and a second end adjacent the collector, and the slot tapers away from the first end to the second end;   wherein the impeller is positioned within the cavity with the top surface of the plurality of blades aligned a lowermost surface of a portion of the slot formed by the top housing portion, and the top surface of the impeller plate aligned an uppermost surface of a portion of the slot formed by the bottom housing portion.   
     
     
         12 . The blower of  claim 11 , wherein the top surface of the plurality of blades is aligned with a peak of the top housing portion along the slot, and the top surface of the impeller plate is aligned with a peak of bottom housing portion along the slot. 
     
     
         13 . The blower of  claim 11 , wherein the slot tapers between the first and second ends at an angle within a range of 10-40 degrees. 
     
     
         14 . The blower of  claim 11 , wherein a gap between the top surface of the plurality of blades, at a tip of the respective blade, and the inside surface of the top housing portion is within a range of 0.005-0.050 inch. 
     
     
         15 . The blower of  claim 11 , wherein the bottom housing portion comprises an inside wall that is proximate to an outside edge of the impeller plate, and a gap between the inside wall and the outside edge is in a range of 0.035-0.110 inch. 
     
     
         16 . The blower of  claim 11 , wherein the bottom housing portion comprises a shelf, and the impeller plate further comprises a bottom surface disposed over a portion of the shelf, and s gap between the bottom surface of the impeller plate and the shelf of the housing is less than or equal to 0.050 inch. 
     
     
         17 . The blower of  claim 11 , wherein the collector is formed as a volute. 
     
     
         18 . The blower of  claim 11 , wherein the top surface of each of the plurality of blades comprises a centerline from a tip of the respective blade to an inlet end of the respective blade, and each of the plurality of blades comprises a width that increases radially outward, from an inlet end toward a leading surface of the respective blade. 
     
     
         19 . The blower of  claim 18 , wherein a maximum width of each blade is at least twice a width of an initial width proximate to the inlet end of the respective blade. 
     
     
         20 . The blower of  claim 11 , further comprising a sound-damping layer disposed on a portion of the housing.