Abradable seal between a turbine rotor and a stationary component

Abstract

A seal between rotary and stationary turbine components includes an abradable coating on the surface of the stationary component between axially spaced caulked-in seal strips. The rotatable component includes a plurality of axially spaced teeth interdigitated with the teeth of the stationary component and engaging the abradable coating on the stationary component in the cold condition of the turbine. The teeth on the stationary component have larger clearances to prevent mushrooming of the tips in the event of a transient condition. By utilizing caulked-in teeth, a larger number of seal teeth are provided for the same axial extent as compared with conventional labyrinth seal teeth.

1 . A turbine comprising: 
 a rotor;    a stationary component;    an end shaft seal between said rotor and said stationary component;    said seal including (i) a plurality of teeth carried by said rotor at axially spaced locations therealong and projecting generally radially outwardly therefrom and (ii) a plurality of teeth carried by said stationary component at axially spaced locations therealong and projecting generally radially inwardly therefrom;    said teeth carried by said rotor and said teeth carried by said stationary component being interdigitated and axially spaced from one another; and    an abradable coating on said stationary component between the teeth thereof at locations in radial opposition to the teeth on the rotor.    
   
   
       2 . A turbine according to  claim 1  wherein the teeth on at least one of said rotor and said stationary component includes strips of metal mechanically secured to said one of said rotor and said stationary component.  
   
   
       3 . A turbine according to  claim 2  wherein the teeth of said one of said rotor and said stationary component have a generally L-shaped configuration with a base of the L-shaped configuration imbedded in a groove in said one of said rotor and said stationary component.  
   
   
       4 . A turbine according to  claim 1  wherein said stationary component includes a plurality of arcuate seal segments about said rotor, said teeth of said stationary component being carried by said seal segments, said seal segments being movable toward and away from said rotor.  
   
   
       5 . A turbine according to  claim 1  wherein the teeth on said rotor in a cold condition of the turbine project radially from said rotor into contact with the abradable coating.  
   
   
       6 . A turbine according to  claim 1  wherein the teeth on said rotor and said stationary component include strips of metal mechanically secured respectively to said rotor and said stationary component.  
   
   
       7 . A turbine according to  claim 1  including an abradable coating on said rotor between the teeth thereof at locations in radial opposition to the teeth carried by the stationary component.  
   
   
       8 . A turbine comprising: 
 a rotor;    a stationary component;    a seal between said rotor and said stationary component;    said seal including (i) a plurality of teeth carried by said rotor at axially spaced locations therealong and projecting generally radially outwardly therefrom and (ii) a plurality of teeth formed by strips of metal mechanically secured to said stationary component at axially spaced locations therealong and projecting generally radially inwardly therefrom toward said rotor; said teeth carried by said rotor and said teeth strips carried by said stationary component being axially spaced from one another; and    an abradable coating on said stationary component between said teeth strips at locations in radial opposition to the teeth on said rotor.    
   
   
       9 . A turbine according to  claim 8  wherein said teeth on said rotor and said teeth strips on said stationary component are interdigitated.  
   
   
       10 . A turbine according to  claim 8  wherein said teeth strips on said stationary component have a generally L-shaped configuration with a base of the L being imbedded in a groove on the stationary component.  
   
   
       11 . A turbine according to  claim 8  wherein the teeth on said rotor comprise metal strips mechanically secured to said rotor.  
   
   
       12 . A turbine according to  claim 8  wherein said teeth on said rotor in a cold condition of the turbine project radially outwardly in contact with the abradable coating on the stationary component.  
   
   
       13 . A turbine according to  claim 8  including an abradable coating on said rotor between the teeth thereof at locations in radial opposition to the teeth carried by the stationary component.