Tangential entry dovetail cantilever load sharing

Abstract

Tangential entry dovetail cantilever load sharing is described herein. In one embodiment, a turbine bucket dovetail is provided that facilitates substantially even distribution of centrifugal loads on a plurality of hooks that define the bucket dovetail.

1 . A bucket dovetail for securing a bucket to a rotor wheel, comprising:
 a plurality of hooks that connect the bucket with the rotor wheel, the plurality of hooks shaped to distribute centrifugal loads placed on the bucket in a substantially even distribution among each of the plurality of hooks.   
     
     
         2 . The dovetail according to  claim 1 , wherein some of the plurality of hooks form a cantilever to distribute the centrifugal loads. 
     
     
         3 . The dovetail according to  claim 2 , wherein a top portion of the cantilever is defined by a radius and a flat depth. 
     
     
         4 . The dovetail according to  claim 3 , wherein distribution of centrifugal loads by the cantilever is a function of the radius and the flat depth. 
     
     
         5 . The dovetail according to  claim 4 , wherein an increase in the radius and/or an increase in the flat depth is proportional to a decrease in the centrifugal load on the cantilever. 
     
     
         6 . The dovetail according to  claim 3 , wherein stress caused by the centrifugal loads on the cantilever is a function of the radius and the flat depth. 
     
     
         7 . The dovetail according to  claim 6 , wherein an increase in the radius and/or an increase in the flat depth is proportional to a decrease in the stress on the cantilever. 
     
     
         8 . The dovetail according to  claim 3 , wherein the radius ranges from about 2 millimeters (0.079 inches) to about 8 millimeters (0.31 inches). 
     
     
         9 . The dovetail according to  claim 3 , wherein the flat depth ranges from about 2 millimeters (0.079 inches) to about 9 millimeters (0.35 inches). 
     
     
         10 . A turbine rotor including a plurality of turbine buckets coupled with a rotor wheel, each turbine bucket comprising a bucket dovetail having a plurality of bucket dovetail hooks, and the rotor wheel comprising a wheel post dovetail shaped with wheel post dovetail hooks to engage with the bucket dovetail hooks of each bucket dovetail, the connection of the plurality of bucket dovetail hooks from each bucket dovetail with the wheel post dovetail hooks forms at least one pocket therebetween to facilitate substantial sharing of centrifugal loads placed on the turbine bucket by the plurality of bucket dovetail hooks. 
     
     
         11 . The turbine rotor according to  claim 10 , wherein a top portion of each of the plurality of bucket dovetail hooks comprises a radius and a flat depth. 
     
     
         12 . The turbine rotor according to  claim 11 , wherein the sharing of the centrifugal loads by each of the plurality of bucket dovetail hooks is a function of the radius and the flat depth. 
     
     
         13 . The turbine rotor according to  claim 11 , wherein the amount of stress caused by the centrifugal loads on each of the plurality of bucket dovetail hooks is a function of the radius and the flat depth. 
     
     
         14 . The turbine rotor according to  claim 11 , wherein the size of the at least one pocket is a function of the radius and the flat depth. 
     
     
         15 . The turbine rotor according to  claim 11 , wherein the radius ranges from about 2 millimeters (0.079 inches) to about 8 millimeters (0.31 inches). 
     
     
         16 . The turbine rotor according to  claim 11 , wherein the flat depth ranges from about 2 millimeters (0.079 inches) to about 9 millimeters (0.35 inches). 
     
     
         17 . A bucket dovetail for securing a bucket to a rotor wheel, comprising:
 a plurality hooks that connect the bucket with the rotor wheel, the plurality of hooks shaped to distribute centrifugal loads placed on the bucket in a desired distribution among each of the plurality of hooks, wherein the desired distribution subjects each of the plurality of hooks to a predetermined amount of centrifugal load and stress.   
     
     
         18 . The dovetail according to  claim 17 , wherein some of the plurality of hooks form a cantilever to distribute the centrifugal loads. 
     
     
         19 . The dovetail according to  claim 18 , wherein a top portion of the cantilever is defined by a radius and a flat depth. 
     
     
         20 . The dovetail according to  claim 19 , wherein distribution of centrifugal loads by the cantilever is a function of the radius and the flat depth.