Sheath with extended wings

Abstract

A sheath for a fan airfoil having a leading edge and a trailing edge in a chordwise direction, a tip and a root in a spanwise direction, a suction side and a pressure side includes a solid portion to wrap around the airfoil leading edge; a first wing attached to the suction side of the airfoil; and a second wing attached to the pressure side of the airfoil. At least one of the first wing and the second wing extends at least about 35% of the chord of the airfoil.

1 . A sheath for a fan airfoil having a leading edge and a trailing edge in a chordwise direction, a tip and a root in a spanwise direction, a suction side and a pressure side, the sheath comprising:
 a solid portion to wrap around the airfoil leading edge;   a first wing attached to the suction side of the airfoil; and   a second wing attached to the pressure side of the airfoil, wherein at least one of the first wing and the second wing extends at least about 35% of the chord of the airfoil.   
     
     
         2 . The sheath of  claim 1 , wherein the at least one of the first wing and the second wing extends at least about 35% of the chord of the airfoil in a region of the airfoil near the tip. 
     
     
         3 . The sheath of  claim 1 , wherein the first wing extends at least about 35% of the chord of the airfoil in a region of the airfoil near the tip. 
     
     
         4 . The sheath of  claim 1 , wherein the second wing extends at least about 45% of the chord of the airfoil in a region of the airfoil near the tip. 
     
     
         5 . The sheath of  claim 1 , wherein each of the first and second wings extend at least about 35% of the chord of the airfoil in a region of the airfoil near the tip. 
     
     
         6 . The sheath of  claim 1 , wherein the first wing covers at least about 30% of the suction side of the airfoil. 
     
     
         7 . The sheath of  claim 1 , wherein the second wing covers at least about 35% of the pressure side of the airfoil. 
     
     
         8 . The sheath of  claim 1 , wherein the sheath is titanium. 
     
     
         9 . The sheath of  claim 1 , wherein at least one of the first and the second wings are tapered. 
     
     
         10 . The sheath of  claim 1 , wherein the first and the second wings are secured to the sides of the airfoil by bonding. 
     
     
         11 . A fan blade for a gas turbine engine, the fan blade comprising:
 an airfoil with a leading edge, a trailing edge, a tip, a suction side and a pressure side; and   a sheath with a solid portion that covers the leading edge, a first wing which covers at least about 30% of the suction side of the airfoil and a second wing which covers at least about 35% of the pressure side of the airfoil.   
     
     
         12 . The fan blade of  claim 11 , wherein the first wing secures the sheath to the airfoil suction side by bonding and the second wing secures the sheath to the airfoil pressure side by bonding. 
     
     
         13 . The fan blade of  claim 11 , wherein the first wing extends at least about 35% of the suction side of the blade from leading edge to trailing edge in a region of the airfoil near the tip. 
     
     
         14 . The fan blade of  claim 11 , wherein the second wing extends at least about 45% of the pressure side of the blade from leading edge to trailing edge in a region of the airfoil near the tip. 
     
     
         15 . The fan blade of  claim 11 , wherein the sheath is titanium. 
     
     
         16 . The fan blade of  claim 11 , wherein the airfoil is aluminum. 
     
     
         17 . The fan blade of  claim 11 , wherein the airfoil is composite. 
     
     
         18 . A method of fabricating a sheath for an airfoil with a leading edge and a trailing edge in a chordwise direction, a tip and a root in a spanwise direction, a suction side and a pressure side, the method comprising:
 forming a solid portion to cover the leading edge of the airfoil;   forming a first wing to extend at least about 35% of the suction side of the airfoil in the chordwise direction in a region of the airfoil; and   forming a second wing to extend at least about 45% of the pressure side of the airfoil in the chordwise direction in a region of the airfoil.   
     
     
         19 . The method of  claim 18 , wherein the solid portion and the first and second wings are formed by machining. 
     
     
         20 . The method of  claim 18 , wherein said region is near the tip.