Fan blade retention system

Abstract

A turbofan engine blade retainer for use in retaining a fan blade to a fan disk. The blade retainer includes a fore blade retainer for limiting forward movement of the fan blade and an aft blade retainer for limiting aft movement of the fan blade. The fore blade retainer engages a fore portion of the fan blade and the aft blade retainer engaging an aft portion of the fan blade.

1 . A gas turbine engine fan assembly, comprising:
 a fan disk having a fore face, an aft face, a slot and a ring slot;   a fan blade having an attachment portion including a fore root face and an aft root face, said attachment portion located within said slot;   a fore blade retainer engageable with the fore root face to limit fore movement of the fan blade; and   an aft blade retainer including a retainer, said retainer located in said ring slot and engageable with said aft root face to limit aft movement of said fan blade.   
   
   
       2 . The assembly of  claim 1 , wherein said retainer is a split ring. 
   
   
       3 . The assembly of  claim 1 , wherein said retainer is a multi-piece structure. 
   
   
       4 . The assembly of  claim 1 , which further includes an aft plate coupled to said aft face and retaining said split ring in the ring slot. 
   
   
       5 . The assembly of  claim 1 , wherein said fan disk includes a forwardly extending arm. 
   
   
       6 . The assembly of  claim 5 , wherein said fore blade retainer is coupled to said forwardly extending arm. 
   
   
       7 . The assembly of  claim 1 , wherein said fore blade retainer includes a first portion for engaging said fore root face and a second portion coupled to said fan disk. 
   
   
       8 . The assembly of  claim 7 , wherein said second portion of said fore blade retainer is coupled to said fan disk. 
   
   
       9 . The assembly of  claim 1 , wherein said retainer includes a first ring portion positioned in said ring slot and a second ring portion extending over a portion of said fan disk. 
   
   
       10 . The assembly of  claim 9 , which further includes an aft plate coupled to said aft face and retaining said retainer in the slot;
 wherein said retainer is a split ring; and   wherein said aft plate is adapted to engage said second ring portion and retain said first ring portion in said ring slot.   
   
   
       11 . The assembly of  claim 9 , which further includes an aft plate coupled to said aft face and retaining said retainer in the slot;
 wherein said retainer is a multi-piece ring; and   wherein said aft plate is adapted to engage said second ring portion and retain said first ring portion in said ring slot.   
   
   
       12 . The assembly of  claim 1 , wherein said fan disk includes a disk lug; and
 wherein said aft blade retainer is coupled to said disk lug.   
   
   
       13 . The assembly of  claim 1 , wherein said fore blade retainer is a thrust ring. 
   
   
       14 . A fan blade assembly for a gas turbine engine comprising:
 a fan disk having a slot;   a fan blade having a root portion disposed in said slot; and   means for retaining said root portion in said slot.   
   
   
       15 . The fan blade assembly of  claim 14 , wherein said means for retaining including a fore blade retainer for limiting fore movement of the fan blade; and
 an aft blade retainer including a ring disposed within a second slot in said fan disk for limiting aft movement of the fan blade.   
   
   
       16 . The fan blade assembly of  claim 14 , wherein said fan blade defines a plurality of fan blades, each of said plurality of fan blades having a root portion disposed in said slot; and
 said means for retaining maintaining each of said root portions in said slot.   
   
   
       17 . The fan blade assembly of  claim 16 , wherein said means for retaining including a fore blade retainer for limiting fore movement of the plurality of fan blade; and
 an aft blade retainer including a ring disposed within a second slot in said fan disk for limiting aft movement of the fan blades.   
   
   
       18 . The fan blade assembly of  claim 16 , wherein said ring is a multi-piece ring. 
   
   
       19 . A method of retaining a fan blade within a gas turbine engine fan disk, comprising:
 placing an attachment portion of the fan blade into a slot in a fan disk;   engaging a fore face of the attachment portion with a fore blade retainer to retain fore movement of the fan blade in the slot;   inserting a retainer ring into a circumferential slot in the fan disk, at least a portion of the retainer ring engaging an aft face of the attachment portion to retain aft movement of the fan blade in the slot; and   coupling an aft plate to the fan disk, the aft plate engaging the retainer ring to retain the retainer ring in the circumferential slot.   
   
   
       20 . The method of  claim 19 , wherein said inserting includes placing the pieces from a multi-piece ring into the circumferential slot. 
   
   
       21 . The method of  claim 19 , wherein the retainer ring is a split ring. 
   
   
       22 . The method of  claim 19 , further comprising coupling a portion of the fore blade retainer to a portion of the fan disk. 
   
   
       23 . The method of  claim 19 , which further includes transferring a centrifugal load associated with the retainer ring to the aft plate. 
   
   
       24 . The method of  claim 19 , which further includes shielding a portion of the disk and aft face of the attachment portion from windage.