Windage shield

Abstract

A windage shield (200′, 200″) for mounting on a fan disc (100′, 100″) of a fan (23) of a gas turbine engine (10), the windage shield (200′, 200″) comprising: a fan disc contacting portion (215′, 215″) adapted to contact and structurally support a rear portion of the fan disc (100′, 100″); wherein the fan disc contacting portion (215′, 215″) includes one or more stiffening elements (205′, 205″) to locally increase the hoop stiffness of the windage shield (200′, 200″).

What is claimed is: 
     
         1 . A windage shield for mounting on a fan disc of a fan of a gas turbine engine, the windage shield comprising: a fan disc contacting portion adapted to contact and structurally support a rear portion of the fan disc; wherein the fan disc contacting portion includes one or more stiffening elements to locally increase the hoop stiffness of the windage shield. 
     
     
         2 . A windage shield according to  claim 1 , wherein at least one of the one or more stiffening elements is integral to the fan disc contacting portion. 
     
     
         3 . A windage shield according to  claim 1 , wherein at least one of the one or more stiffening elements is provided as an insert receivable partially or fully on or in the fan disc contacting portion. 
     
     
         4 . A windage shield according to  claim 1 , wherein at least one of the one or more stiffening elements comprises, or consists essentially of, a composite material such as a metal matrix composite or a ceramic matrix composite. 
     
     
         5 . A windage shield according to  claim 1 , wherein at least one of the one or more stiffening elements comprises, or consists essentially of, a metal or alloy such as nickel alloy, titanium, a titanium alloy, aluminium or an aluminium alloy. 
     
     
         6 . A fan for a gas turbine engine, the fan comprising:
 a fan disc; and   at least one windage shield according to  claim 1  mounted on the fan disc.   
     
     
         7 . A fan according to  claim 6 , wherein the windage shield is mounted on a rear portion of the fan disc. 
     
     
         8 . A fan according to  claim 7 , the fan disc further comprising disc posts for locating a blade mounted on the fan disc, wherein at least one of the one or more stiffening elements is located on the disc posts radially outwardly of the disc posts. 
     
     
         9 . A fan according to  claim 7 , the fan disc comprising a protrusion extending axially rearwardly, wherein at least one of the one or more stiffening elements is disposed on and/or adjacent the protrusion. 
     
     
         10 . A gas turbine engine for an aircraft comprising:
 an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; and   a fan as claimed in  claim 6  located upstream of the engine core.   
     
     
         11 . A gas turbine engine according to  claim 10 , further comprising a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft.