Integrated nozzle and bucket wheels for reaction steam turbine stationary components and related method

Abstract

Integrated nozzle and bucket wheels for turbine stator and rotor components, respectively, include a three hundred sixty degree wheel formed from a single piece of stock material. The nozzle wheels include radially inner portions formed to include a plurality of nozzles, while the bucket wheels are each formed to include a plurality of buckets. The nozzle and bucket wheels may be split into plural arcuate segments.

1 . An integrated bucket wheel for a turbine rotor component comprising a three hundred sixty degree wheel formed from a single piece of stock material, a radially outer portion of said wheel manufactured to include a plurality of buckets, each having an airfoil portion and a radially outer tip shroud portion; and a radially inner portion of said bucket wheel manufactured to include one or more assembly features.  
   
   
       2 . The integrated bucket wheel of  claim 1  wherein said assembly features include a plurality of tie-rod or bolt holes radially inward of said airfoil portions.  
   
   
       3 . The integrated bucket wheel of  claim 2  wherein said tie-rod or bolt holes are circumferentially spaced about said radially inner portion.  
   
   
       4 . The integrated bucket wheel of  claim 1  wherein said bucket wheel is split into two or more arcuate segments.  
   
   
       5 . The integrated bucket wheel of  claim 1  wherein said stock material comprises a forged stock.  
   
   
       6 . The integrated bucket wheel of  claim 1  wherein said stock material comprises rolled ring stock.  
   
   
       7 . The integrated bucket wheel of  claim 1  wherein said stock material comprises generally flat plate stock.  
   
   
       8 . The integrated bucket wheel of  claim 1  including a center opening adapted to receive a turbine rotor.  
   
   
       9 . An integrated bucket wheel for a rotor component of a reaction turbine comprising a unitary 360° piece of stock material having a radially outer portion machined to include a plurality of buckets, each having an airfoil portion and a radially outer tip shroud portion; and a radially inner portion machined to include a plurality of tie-rod or bolt holes circumferentially spaced about said radially inner portions.  
   
   
       10 . The integrated bucket wheel of  claim 9  wherein said stock material comprises a forged stock.  
   
   
       11 . The integrated bucket wheel of  claim 9  wherein said stock material comprises rolled ring stock.  
   
   
       12 . The integrated bucket wheel of  claim 9  wherein said stock material comprises generally flat plate stock.  
   
   
       13 . A method of making a turbine bucket wheel comprising forming flat stock material into an annular ring; machining a radially outer portion of said annular ring to include a plurality of buckets, each comprising an airfoil portion, and machining a radially inner portion of said annular ring to include assembly features.  
   
   
       14 . The method of  claim 13  wherein said assembly features include a center opening and a plurality of circumferentially spaced tie-rod or bolt holes.  
   
   
       15 . The method of  claim 13  including machining a 360° shroud cover on radially outer tips of said airfoil portions.  
   
   
       16 . The method of  claim 13  wherein said stock material comprises a forged stock.  
   
   
       17 . The method of  claim 13  wherein said stock material comprises rolled ring stock.  
   
   
       18 . The method of  claim 13  wherein said stock material comprises generally flat plate stock.