Fan blade

Abstract

The present invention employs improved fan blade shapes to improve fan blade performance in one or more manners (i.e., increased fan efficiency, lower fan noise, greater fluid moving capability, and the like). In some embodiments, the fan blade has a front side, a rear side, an inner attachment portion, an outer edge, a curved leading edge and a curved trailing edge. The outer edge can define an arc between a forward position and a rearward position of the fan blade. In some embodiments, the leading edge extends outward and intercepts the arc of the outer edge at the forward position, and the trailing edge extends outward to the rearward position. Various angles, lengths, and other dimensions of the blade can have selected values to produce superior fan performance.

What is claimed is:  
     
         1 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body having a front side and a back side;    forming an arcuate concave leading edge of the fan blade on the blade body, the arcuate concave leading edge extending along a first arcuate line;    forming an arcuate convex trailing edge of the fan blade on the blade body; and    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade, the first and second lines intersecting at a first point;    wherein the arcuate concave leading edge is formed to have a second point at a location on the arcuate concave leading edge substantially equal to 0.65 times the radius of the fan blade, and wherein an angle between a first straight line extending from the axis to the first point and a second straight line extending from the axis to the second point is between 15 and 45 degrees.    
     
     
         2 . The method as claimed in  claim 1 , wherein the angle is between 20 and 35 degrees.  
     
     
         3 . The method as claimed in  claim 1 , wherein the angle is between 25 and 35 degrees.  
     
     
         4 . The method as claimed in  claim 1 , wherein the arcuate concave leading edge has a camber-to-chord ratio between the first and second points of between 0 and 0.22.  
     
     
         5 . The method as claimed in  claim 1 , wherein the arcuate concave leading edge is formed to have a camber-to-chord ratio between the first and second points of between 0.05 and 0.17.  
     
     
         6 . The method as claimed in  claim 1 , wherein the arcuate concave leading edge is formed to have a camber-to-chord ratio between the first and second points of between 0.08 and 0.13.  
     
     
         7 . The method as claimed in  claim 1 , wherein: 
 the arcuate convex trailing edge extends along a third arcuate line intersecting the second line at a third point;    the arcuate convex trailing edge is formed to have a fourth point at a location substantially equal to 0.65 times the radius of the fan blade; and    an angle defined between a third straight line extending from the axis to the third point and a fourth straight line extending from the axis to the fourth point is between 10 and 35 degrees.    
     
     
         8 . The method as claimed in  claim 7 , wherein the angle between the third and fourth straight lines is between 15 and 30 degrees.  
     
     
         9 . The method as claimed in  claim 7 , wherein the angle between the third and fourth straight lines is between 20 and 25 degrees.  
     
     
         10 . The method as claimed in  claim 1 , wherein: 
 the arcuate convex trailing edge extends along a third arcuate line intersecting the second line at a third point;    the arcuate convex trailing edge is formed to have a fourth point at a location substantially equal to 0.65 times the radius of the fan blade; and    the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0 and 0.20.    
     
     
         11 . The method as claimed in  claim 10 , wherein the camber-to-chord ratio is between 0.05 and 0.17.  
     
     
         12 . The method as claimed in  claim 10 , wherein the camber-to-chord ratio is between 0.07 and 0.17.  
     
     
         13 . The method as claimed in  claim 4 , wherein: 
 the arcuate convex trailing edge extends along a third arcuate line intersecting the second line at a third point;    the arcuate convex trailing edge is formed to have a fourth point at a location substantially equal to 0.65 times the radius of the fan blade; and    an angle defined between a third straight line extending from the axis to the third point and a fourth straight line extending from the axis to the fourth point is between 10 and 35 degrees.    
     
     
         14 . The method as claimed in  claim 13 , wherein the angle between the third and fourth straight lines is between 15 and 30 degrees.  
     
     
         15 . The method as claimed in  claim 14 , wherein the angle between the third and fourth straight lines is between 20 and 25 degrees.  
     
     
         16 . The method as claimed in  claim 4 , wherein: 
 the arcuate convex trailing edge extends along a third arcuate line intersecting the second line at a third point;    the arcuate convex trailing edge is formed to have a fourth point at a location substantially equal to 0.65 times the radius of the fan blade; and    the arcuate convex trailing edge has a camber-to-chord ratio between the third and fourth points of between 0 and 0.20.    
     
     
         17 . The method as claimed in  claim 16 , wherein the camber-to-chord ratio between the third and fourth points is between 0.05 and 0.17.  
     
     
         18 . The method as claimed in  claim 16 , wherein the camber-to-chord ratio between the third and fourth points is between 0.07 and 0.12.  
     
     
         19 . The method as claimed in  claim 7 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0 and 0.20.  
     
     
         20 . The method as claimed in  claim 7 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0.05 and 0.17.  
     
     
         21 . The method as claimed in  claim 7 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0.07 and 0.12.  
     
     
         22 . The method as claimed in  claim 13 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0 and 0.20.  
     
     
         23 . The method as claimed in  claim 13 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0.05 and 0.17.  
     
     
         24 . The method as claimed in  claim 13 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the third and fourth points of between 0.07 and 0.12.  
     
     
         25 . The method as claimed in  claim 1 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.65 times the radius of the fan blade has a camber-to-chord ratio of between 4.0% and 7.5%.  
     
     
         26 . The method as claimed in  claim 25 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.5% and 6.5%.  
     
     
         27 . The method as claimed in  claim 25 , wherein the camber-to-chord ratio of the cross-sectional shape is between 5.0% and 6.0%.  
     
     
         28 . The method as claimed in  claim 1 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.75 times the radius of the fan blade has a camber-to-chord ratio of between 3.5% and 7.0%.  
     
     
         29 . The method as claimed in  claim 28 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.0% and 6.0%.  
     
     
         30 . The method as claimed in  claim 28 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.5% and 5.5%.  
     
     
         31 . The method as claimed in  claim 1 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.85 times the radius of the fan blade has a camber-to-chord ratio of between 3.0% and 6.5%.  
     
     
         32 . The method as claimed in  claim 31 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.0% and 5.0%.  
     
     
         33 . The method as claimed in  claim 31 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.5% and 4.5%.  
     
     
         34 . The method as claimed in  claim 1 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.95 times the radius of the fan blade has a camber-to-chord ratio of between 2.0% and 5.5%.  
     
     
         35 . The method as claimed in  claim 34 , wherein the camber-to-chord ratio of the cross-sectional shape is between 2.5% and 4.5%.  
     
     
         36 . The method as claimed in  claim 34 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.0% and 4.0%.  
     
     
         37 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body having a front side and a back side;    forming an arcuate concave leading edge of the fan blade on the blade body;    forming an arcuate convex trailing edge of the fan blade on the blade body, the arcuate convex trailing edge extending along a first arcuate line; and    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade, the first and second lines intersecting at a first point;    wherein the arcuate convex trailing edge is formed to have a second point at a location on the arcuate convex trailing edge substantially equal to 0.65 times the radius of the fan blade, and wherein an angle between a first straight line extending from the axis to the first point and a second straight line extending from the axis to the second point is between 10 and 35 degrees.    
     
     
         38 . The method as claimed in  claim 37 , wherein the angle is between 15 and 30 degrees.  
     
     
         39 . The method as claimed in  claim 37 , wherein the angle is between 20 and 25 degrees.  
     
     
         40 . The method as claimed in  claim 37 , wherein the arcuate convex trailing edge is formed to have a camber-to-chord ratio between the first and second points of between 0 and 0.20.  
     
     
         41 . The method as claimed in  claim 40 , wherein the camber-to-chord ratio is between 0.05 and 0.17.  
     
     
         42 . The method as claimed in  claim 40 , wherein the camber-to-chord ratio is between 0.07 and 0.12.  
     
     
         43 . The method as claimed in  claim 37 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.65 times the radius of the fan blade has a camber-to-chord ratio of between 4.0% and 7.5%.  
     
     
         44 . The method as claimed in  claim 43 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.5% and 6.5%.  
     
     
         45 . The method as claimed in  claim 43 , wherein the camber-to-chord ratio of the cross-sectional shape is between 5.0% and 6.0%.  
     
     
         46 . The method as claimed in  claim 37 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.75 times the radius of the fan blade has a camber-to-chord ratio of between 3.5% and 7.0%.  
     
     
         47 . The method as claimed in  claim 46 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.0% and 6.0%.  
     
     
         48 . The method as claimed in  claim 46 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.5% and 5.5%.  
     
     
         49 . The method as claimed in  claim 37 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.85 times the radius of the fan blade has a camber-to-chord ratio of between 3.0% and 6.5%.  
     
     
         50 . The method as claimed in  claim 49 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.0% and 5.0%.  
     
     
         51 . The method as claimed in  claim 49 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.5% and 4.5%.  
     
     
         52 . The method as claimed in  claim 37 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.95 times the radius of the fan blade has a camber-to-chord ratio of between 2.0% and 5.5%.  
     
     
         53 . The method as claimed in  claim 52 , wherein the camber-to-chord ratio of the cross-sectional shape is between 2.5% and 4.5%.  
     
     
         54 . The method as claimed in  claim 52 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.0% and 4.0%.  
     
     
         55 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body having a front side and a back side;    forming an arcuate concave leading edge of the fan blade on the blade body;    forming an arcuate convex trailing edge of the fan blade on the blade body, the arcuate convex trailing edge extending along a first arcuate line; and    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade, the first and second lines intersecting at a first point;    wherein the arcuate convex trailing edge is formed to have a second point at a location on the arcuate convex trailing edge substantially equal to 0.65 times the radius of the fan blade, the arcuate convex trailing edge having a camber-to-chord ratio between the first and second points of between 0 and 0.20.    
     
     
         56 . The method as claimed in  claim 55 , wherein the camber-to-chord ratio is between 0.05 and 0.17.  
     
     
         57 . The method as claimed in  claim 55 , wherein the camber-to-chord ratio is between 0.07 and 0.12.  
     
     
         58 . The method as claimed in  claim 55 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.65 times the radius of the fan blade has a camber-to-chord ratio of between 4.0% and 7.5%.  
     
     
         59 . The method as claimed in  claim 58 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.5% and 6.5%.  
     
     
         60 . The method as claimed in  claim 58 , wherein the camber-to-chord ratio of the cross-sectional shape is between 5.0% and 6.0%.  
     
     
         61 . The method as claimed in  claim 55 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.75 times the radius of the fan blade has a camber-to-chord ratio of between 3.5% and 7.0%.  
     
     
         62 . The method as claimed in  claim 61 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.0% and 6.0%.  
     
     
         63 . The method as claimed in  claim 61 , wherein the camber-to-chord ratio of the cross-sectional shape is between 4.5% and 5.5%.  
     
     
         64 . The method as claimed in  claim 55 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.85 times the radius of the fan blade has a camber-to-chord ratio of between 3.0% and 6.5%.  
     
     
         65 . The method as claimed in  claim 64 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.0% and 5.0%.  
     
     
         66 . The method as claimed in  claim 64 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.5% and 4.5%.  
     
     
         67 . The method as claimed in  claim 55 , further comprising forming the blade body with a concave front surface and a convex rear surface, wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.95 times the radius of the fan blade has a camber-to-chord ratio of between 2.0% and 5.5%.  
     
     
         68 . The method as claimed in  claim 67 , wherein the camber-to-chord ratio of the cross-sectional shape is between 2.5% and 4.5%.  
     
     
         69 . The method as claimed in  claim 67 , wherein the camber-to-chord ratio of the cross-sectional shape is between 3.0% and 4.0%.  
     
     
         70 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body;    forming an arcuate concave leading edge of the fan blade on the blade body;    forming an arcuate convex trailing edge of the fan blade on the blade body;    forming a concave front surface on the blade body;    forming a convex rear surface on the blade body;    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade;    wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.65 times the radius of the fan blade has a camber-to-chord ratio of between 4.0% and 7.5%.    
     
     
         71 . The method as claimed in  claim 70 , wherein the camber-to-chord ratio is between 4.5% and 6.5%.  
     
     
         72 . The method as claimed in  claim 70 , wherein the camber-to-chord ratio is between 5.0% and 6.0%.  
     
     
         73 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body;    forming an arcuate concave leading edge of the fan blade on the blade body;    forming an arcuate convex trailing edge of the fan blade on the blade body;    forming a concave front surface on the blade body;    forming a convex rear surface on the blade body;    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade;    wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.75 times the radius of the fan blade has a camber-to-chord ratio of between 3.5% and 7.0%.    
     
     
         74 . The method as claimed in  claim 73 , wherein the camber-to-chord ratio is between 4.0% and 6.0%.  
     
     
         75 . The method as claimed in  claim 73 , wherein the camber-to-chord ratio is between 4.5% and 5.5%.  
     
     
         76 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body;    forming an arcuate concave leading edge of the fan blade on the blade body;    forming an arcuate convex trailing edge of the fan blade on the blade body;    forming a concave front surface on the blade body;    forming a convex rear surface on the blade body;    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade;    wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.85 times the radius of the fan blade has a camber-to-chord ratio of between 3.0% and 6.5%.    
     
     
         77 . The method as claimed in  claim 76 , wherein the camber-to-chord ratio is between 3.0% and 5.0%.  
     
     
         78 . The method as claimed in  claim 76 , wherein the camber-to-chord ratio is between 3.5% and 4.5%.  
     
     
         79 . A method of manufacturing a fan blade for rotation about an axis, the method comprising: 
 providing a blade body;    forming an arcuate concave leading edge of the fan blade on the blade body;    forming an arcuate convex trailing edge of the fan blade on the blade body;    forming a concave front surface on the blade body;    forming a convex rear surface on the blade body;    forming an outer edge of the fan blade on the blade body, the outer edge extending along a second line at a free end of the blade body and at least partially defining a radius of the fan blade;    wherein a cross-sectional shape defined at a cross-section of the blade body taken at 0.85 times the radius of the fan blade has a camber-to-chord ratio of between 2.0% and 5.5%.    
     
     
         80 . The method as claimed in  claim 79 , wherein the camber-to-chord ratio is between 2.5% and 4.5%.  
     
     
         81 . The method as claimed in  claim 79 , wherein the camber-to-chord ratio is between 3.0% and 4.0%.