Variable clearance mechanism for use in a turbine engine and method of assembly

Abstract

A variable clearance mechanism for use in a turbine engine is provided that includes a stationary component, a plurality of articulating seal members coupled to the stationary component, and a biasing mechanism including an actuation ring. The variable clearance mechanism varies the position of stationary seal members to provide variable bucket tip clearance as a function of an operating condition of the turbine engine. The biasing mechanism is coupled to the plurality of articulating seal members for use in selectively translating the plurality of articulating seal members when the actuation ring is rotated circumferentially relative to the stationary component.

What is claimed is: 
     
         1 . A variable clearance mechanism for use in a turbine engine, said mechanism comprising:
 a stationary component;   a plurality of articulating seal members coupled to said stationary component; and   a biasing mechanism comprising an actuation ring, said biasing mechanism coupled to said plurality of articulating seal members for use in selectively translating said plurality of articulating seal members when said actuation ring is rotated circumferentially relative to said stationary component.   
     
     
         2 . The mechanism in accordance with  claim 1 , wherein said actuation ring is rotated in a first circumferential direction to translate said plurality of articulating seal members radially inward, and said actuation ring is rotated in a second circumferential direction to translate said plurality of articulating seal members radially outward. 
     
     
         3 . The mechanism in accordance with  claim 2 , wherein a degree of translation of said plurality of articulating seal members is selected based on a degree of rotation of said actuation ring in the first and second circumferential directions. 
     
     
         4 . The mechanism in accordance with  claim 1 , wherein said biasing mechanism comprises at least one lever coupled between said actuation ring and at least one of said plurality of articulating seal members, wherein said at least one lever is configured to convert circumferential movement of said actuation ring into substantially linear movement of said plurality of articulating seal members. 
     
     
         5 . The mechanism in accordance with  claim 4 , wherein said biasing mechanism comprises at least one lever coupled between said actuation ring and each of said plurality of articulating seal members such that said plurality of articulating seal members are simultaneously translated when said actuation ring is rotated circumferentially. 
     
     
         6 . The mechanism in accordance with  claim 1 , wherein said biasing mechanism comprises an actuator coupled to said actuation ring, said actuator configured to induce circumferential rotation to said actuation ring. 
     
     
         7 . The mechanism in accordance with  claim 1 , wherein said actuation ring is configured to remain at a substantially uniform distance from said stationary component as said actuation ring rotates circumferentially. 
     
     
         8 . A turbine engine comprising:
 a rotor blade assembly comprising a plurality of rotor blades;   a stationary component;   a plurality of articulating seal members coupled to said stationary component; and   a biasing mechanism comprising an actuation ring, said biasing mechanism coupled to said plurality of articulating seal members for use in selectively translating said plurality of articulating seal members when said actuation ring is rotated circumferentially relative to said stationary component.   
     
     
         9 . The turbine engine in accordance with  claim 8 , wherein said actuation ring is rotated in a first circumferential direction to translate said plurality of articulating seal members radially inward, and said actuation ring is rotated in a second circumferential direction to translate said plurality of articulating seal members radially outward. 
     
     
         10 . The turbine engine in accordance with  claim 9 , wherein a clearance between said plurality of articulating seal members and said plurality of rotor blades is selected based on a degree of rotation of said actuation ring in the first and second circumferential directions. 
     
     
         11 . The turbine engine in accordance with  claim 8 , wherein said biasing mechanism comprises at least one lever coupled between said actuation ring and at least one of said plurality of articulating seal members, wherein said at least one lever is configured to convert circumferential movement of said actuation ring into substantially linear movement of said plurality of articulating seal members. 
     
     
         12 . The turbine engine in accordance with  claim 8  further comprising a slide track coupled to adjacent articulating seal members, said slide track configured to substantially maintain alignment between said adjacent articulating seal members as they selectively translate linearly. 
     
     
         13 . The turbine engine in accordance with  claim 8 , wherein said biasing mechanism comprises a biasing element coupled to at least one of said plurality of articulating seal members, said biasing element configured to ensure the selective translation of said at least one of said plurality of articulating seal members is responsive to the circumferential rotation of said actuation ring. 
     
     
         14 . The turbine engine in accordance with  claim 8  further comprising a rack and pinion assembly associated with said actuation ring and configured to facilitate translating said plurality of articulating seal members in response to rotation of said actuation ring relative to said stationary component. 
     
     
         15 . A method of assembling a variable clearance mechanism for use in a turbine engine, said method comprising:
 providing a stationary component;   coupling a plurality of articulating seal members to the stationary component;   coupling an actuation ring to the plurality of articulating seal members such that the actuation ring is configured to selectively translate the plurality of articulating seal members when the actuation ring is rotated circumferentially relative to the stationary component.   
     
     
         16 . The method in accordance with  claim 15 , wherein coupling the actuation ring to the plurality of articulating seal members comprises coupling at least one lever between the actuation ring and the plurality of articulating seal members. 
     
     
         17 . The method in accordance with  claim 16 , wherein coupling at least one lever comprises coupling the at least one lever between the actuation ring and each of the plurality of articulating seal members such that the plurality of articulating seal members are simultaneously translated when the actuation ring is rotated circumferentially. 
     
     
         18 . The method in accordance with  claim 16  further comprising forming a slot in at least one of the stationary component and the at least one lever, wherein the slot facilitates sliding engagement between the at least one lever and at least one of the actuation ring, the stationary component, and the plurality of articulating seal members. 
     
     
         19 . The method in accordance with  claim 15  further comprising coupling an actuator to the actuation ring, wherein the actuator is configured to induce circumferential rotation to the actuation ring. 
     
     
         20 . The method in accordance with  claim 15  further comprising defining a distance between the stationary component and the actuation ring that remains substantially uniform as the actuation ring rotates circumferentially.