Fan Assembly With Fan Blade Under-Root Spacer

Abstract

A fan assembly is disclosed which includes a rotor having an outer periphery and at least one slot extending radially inwardly through the outer periphery. The slot terminates at a base surface disposed at a radial depth from the outer periphery of the rotor. The fan assembly also includes at least one fan blade that includes an airfoil connected to a root. The root is received in the slot. The root terminates in an inner face having a radial length that is less than the radial depth of the Slot to define a gap between the inner face of the root and the base surface of the slot when the root is bias away to the base surface of the slot. A spacer is disposed within a gap, wherein a spacer is fabricated from a polymer, which may be a composite material such as a polymer embedded with reinforcing materials such as carbon fibers and glass fibers.

What is claimed: 
     
         1 . A fan assembly comprising:
 a rotor having an outer periphery and at least one slot extending radially inwardly through the outer periphery and terminating at a base surface disposed at a radial depth from the outer periphery of the rotor;   at least one fan blade including an airfoil connected to a root, the root being received in the slot, the root terminating at an inner face and having a radial length that is less than the radial depth of the slot to define a gap between the inner face of the root and the base surface of the slot;   a spacer disposed in the gap, the spacer being fabricated from a polymer.   
     
     
         2 . The fan assembly of  claim 1  wherein the polymer is embedded with at least one reinforcing material. 
     
     
         3 . The fan assembly of  claim 2  wherein the reinforcing material is selected from the group consisting of carbon fibers and glass fibers. 
     
     
         4 . The fan assembly of  claim 1  wherein the spacer is injection-molded. 
     
     
         5 . The fan assembly of  claim 1  wherein the polymer is selected from the group consisting of: polyamide, polyetherimide (PEI), polyimide, polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polysulfone, nylon, polyphenylsulfide, polyester, and combinations thereof. 
     
     
         6 . The fan assembly of  claim 2  wherein the polymer is selected from the group consisting of: polyamide, polyetherimide (PEI), polyimide, polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polysulfone, nylon, polyphenylsulfide, polyester, and combinations thereof. 
     
     
         7 . The fan assembly of  claim 1  wherein the slot has a dovetail-shaped cross-sectional profile. 
     
     
         8 . The fan assembly of  claim 1  wherein the base surface is disposed between a pair of sidewalls that extend from the base surface to the outer periphery of the rotor, the sidewalls extending towards each other to form a throat disposed between the base surface and the outer periphery of the rotor, the base surface having a width and the throat having a width; and
 the inner face of the root being disposed between two pressure faces, the inner face having a width that is smaller than the width of the base surface and that is larger than the width of the throat. 
 
     
     
         9 . The fan assembly of  claim 1  wherein the root and slot are shaped so that the root is mateably received in the slot. 
     
     
         10 . A method of coupling a fan blade to a rotor, the method comprising:
 providing a rotor including an outer periphery and at least one slot extending radially through the outer periphery before terminating at a base surface disposed at a radial depth from the outer periphery;   providing at least one fan blade including an airfoil connected to a root, the root terminating at an inner face and having a radial length that is less than the radial depth of the slot;   providing a spacer fabricated from a polymer;   inserting the root of the fan blade into the slot of the rotor;   moving the root radially outwardly away from the base surface of the slot to expose a gap between the inner face of the root and the base surface of the slot; and   inserting the spacer into the gap.   
     
     
         11 . The method of  claim 10  wherein the polymer is embedded with at least one reinforcing material. 
     
     
         12 . The method of  claim 11  wherein the reinforcing material is selected from the group consisting of carbon fibers and glass fibers. 
     
     
         13 . The method of  claim 10  wherein the spacer is injection-molded. 
     
     
         14 . The method of  claim 10  wherein the polymer is selected from the group consisting of: polyamide, polyetherimide (PEI), polyimide, polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polysulfone, nylon, polyphenylsulfide, polyester, and combinations thereof. 
     
     
         15 . The method of  claim 11  wherein the polymer is selected from the group consisting of: polyamide, polyetherimide (PEI), polyimide, polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polysulfone, nylon, polyphenylsulfide, polyester, and combinations thereof. 
     
     
         16 . The method of  claim 10  wherein the slot has a dovetail-shaped cross-sectional profile. 
     
     
         17 . The method of  claim 10  wherein the base surface of the slot is disposed between a pair of sidewalls that extend from the base surface to the outer periphery, the sidewalls extending towards each other to form a throat disposed between the base surface and the outer periphery, the base surface having a width and the throat having a width;
 wherein the inner face of the root is disposed between two pressure faces, the inner face having a width that is smaller than the width of the base surface and that is larger than the width of the throat; 
 the moving of the fan blade radially outward away from the base surface further includes moving of the fan blade radially outward away from the base surface until the two pressure faces of the root engage the throat of the slot. 
 
     
     
         18 . A fan assembly comprising:
 a rotor having an outer periphery and at least one slot extending radially inwardly through the outer periphery and terminating at a base surface disposed at a radial depth from the outer periphery of the rotor;   at least one fan blade including an airfoil connected to a root, the root being received in the slot, the root terminating at an inner face and having a radial length that is less than the radial depth of the slot to define a gap between the inner face of the root and the base surface of the slot when the root is biased away from the base surface of the slot;   a spacer disposed in the gap, the spacer being fabricated from a polymer selected from the group consisting of: polyamide, polyetherimide (PEI), polyimide, polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polysulfone, nylon, polyphenylsulfide, polyester, and combinations thereof.   
     
     
         19 . The fan assembly of  claim 18  wherein the polymer is embedded with at least one reinforcing material. 
     
     
         20 . The fan assembly of  claim 19  wherein the reinforcing material is selected from the group consisting of carbon fibers and glass fibers.