Turbine blade tip shroud

Abstract

A turbine blade that includes a tip shroud and one or more cooling cavities formed within the tip shroud. At least one of the cooling cavities may include a plurality of ribs and a first interior wall that generally opposes a second interior wall across the cooling cavity. The ribs may be configured such that some of the ribs originate on the first interior wall of the cooling cavity and extend toward the second interior wall of the cooling cavity and some of the ribs originate on the second interior wall of the cooling cavity and extend toward the first interior wall of the cooling cavity. And, the ribs that originate on the first interior wall of the cooling cavity and the ribs that originate on the second interior wall of the cooling cavity may have an alternating arrangement.

1 . A turbine blade, comprising:
 a tip shroud; and   one or more cooling cavities formed within the tip shroud;   wherein:
 at least one of the cooling cavities comprises a plurality of ribs and a first interior wall that generally opposes a second interior wall across the cooling cavity; 
 the ribs are configured such that some of the ribs originate on the first interior wall of the cooling cavity and extend toward the second interior wall of the cooling cavity and some of the ribs originate on the second interior wall of the cooling cavity and extend toward the first interior wall of the cooling cavity; and 
 the ribs that originate on the first interior wall of the cooling cavity and the ribs that originate on the second interior wall of the cooling cavity comprise an alternating arrangement. 
   
     
     
         2 . The turbine blade according to  claim 1 , wherein the alternating arrangement comprises alternating the placement of a rib that originates on the first interior wall of the cooling cavity with the placement of a rib that originates on the second interior wall of the cooling cavity. 
     
     
         3 . The turbine blade according to  claim 2 , wherein the alternating arrangement defines a labyrinth cooling circuit within the cooling cavity. 
     
     
         4 . The turbine blade according to  claim 2 , wherein:
 the ribs that originate at the first interior wall of the cooling cavity are oriented and sized so that each extends a partial way across the distance across the cooling cavity; and   the ribs that originate at the second interior wall of the cooling cavity are oriented and sized so that each extends a partial way across the distance across the cooling cavity.   
     
     
         5 . The turbine blade according to  claim 4 , wherein:
 the ribs that originate at the first interior wall of the cooling cavity are oriented and sized so that at least one extends across at least a majority of the distance across the cooling cavity; and   the ribs that originate at the second interior wall of the cooling cavity are oriented and sized so that at least one extends across at least a majority of the distance across the cooling cavity.   
     
     
         6 . The turbine blade according to  claim 5 , wherein the majority of the distance across the cooling cavity comprises at least 75% of the distance across the cooling cavity. 
     
     
         7 . The turbine blade according to  claim 5 , wherein:
 the ribs that originate at the first interior wall of the cooling cavity and the second interior wall define a first gap;   the ribs that originate at the second interior wall of the cooling cavity and the first interior wall define a second gap; and   the first gap and the second gap each comprise a distance across of approximately 0.10 to 0.25 inches.   
     
     
         8 . The turbine blade according to  claim 5 , wherein:
 the ribs that originate at the first interior wall of the cooling cavity and the second interior wall define a first gap;   the ribs that originate at the second interior wall of the cooling cavity and the first interior wall define a second gap; and   
       the first gap and the second gap each comprise a distance across of at least 0.10 inches. 
     
     
         9 . The turbine blade according to  claim 4 , wherein the ribs that originate at the first interior wall of the cooling cavity and the ribs that originate at the second interior wall of the cooling cavity are substantially parallel to each other. 
     
     
         10 . The turbine blade of  claim 2 , wherein all of the one or more cooling cavities are in fluid communication with each other. 
     
     
         11 . The turbine blade of  claim 2 , wherein the one or more cooling cavities comprises at least two cooling cavities; and
 wherein one of the two or more cooling cavities is not in fluid communication with the other cooling cavities.   
     
     
         12 . The turbine blade according to  claim 2 , further comprising an airfoil and at least one coolant passage defined within the airfoil, wherein;
 the one or more cooling cavities comprise a pressure side cooling cavity, a suction side cooling cavity, and a coolant chamber, the coolant chamber comprising a chamber that resides substantially between the pressure side cooling cavity and the suction side cooling cavity;   the coolant chamber is in fluid communication with the coolant passage; and   the coolant chamber is in fluid communication with the pressure side cooling cavity and a suction side cooling cavity via a plurality of coolant chamber apertures.   
     
     
         13 . The turbine blade according to  claim 12 , wherein:
 the ribs comprise a plurality of partition ribs, the partition ribs comprising a plurality of outward extending partition ribs and a plurality of inward extending partition ribs;   the outward extending partition ribs originate from a wall defining the coolant chamber and extend outwardly to a position short of an outer wall of the cooling cavity, thus defining a first gap between the outward extending partition rib and the outer wall of the cooling cavity;   the inward extending partition ribs originate from the outer wall of the cooling cavity and extend inwardly to a position short of the wall defining the coolant chamber, thus defining a second gap between the inward extending partition rib and the wall defining the coolant chamber; and   the partition ribs are arranged such the placement of the outward extending partition rib alternates with the placement of the inward extending partition rib.   
     
     
         14 . The turbine blade according to  claim 13 , wherein:
 the ribs comprise a plurality of truncated ribs, the truncated ribs being substantially shorter than the partition ribs;   the outer wall of the cooling cavity is at least partially defined by one or more of the truncated ribs; and   one or more of the outward extending partition ribs extend from the wall defining the coolant chamber to a position short of the truncated rib that defines the outer wall of the cooling cavity, thus defining the first gap between the outward extending partition rib and the truncated rib.   
     
     
         15 . The turbine blade according to  claim 13 , wherein each of the pressure side cooling cavity and the suction side cooling cavity have between 4 and 7 partition ribs. 
     
     
         16 . The turbine blade according to  claim 2 , further comprising an interior center wall, the interior center wall partially separating the cooling cavity such that a pressure side cooling cavity is formed on one side of the interior center wall and a suction side cooling cavity is formed on the other side of the interior center wall;
 wherein:
 the ribs comprise a plurality of partition ribs, the partition ribs comprising a plurality of outward extending partition ribs and a plurality of inward extending partition ribs; 
 the outward extending partition ribs originate from the interior center wall and extend outwardly to a position short of an outer wall of the cooling cavity, thus defining a first gap between the outward extending partition ribs and the outer wall of the cooling cavity; 
 the inward extending partition ribs originate from the outer wall of the cooling cavity and extend inwardly to a position short of the interior center wall, thus defining a gap between the inward extending partition ribs  146  and the interior center wall; and 
 the partition ribs are arranged such the placement of the outward extending partition rib alternates with the placement of the inward extending partition rib. 
   
     
     
         17 . A turbine blade, comprising:
 a tip shroud; and   one or more cooling cavities formed within the tip shroud;   wherein:
 at least one of the cooling cavities comprises a plurality of ribs and a first interior wall that generally opposes a second interior wall across the cooling cavity; 
 the ribs are configured such that some of the ribs originate on the first interior wall of the cooling cavity and extend toward the second interior wall of the cooling cavity and some of the ribs originate on the second interior wall of the cooling cavity and extend toward the first interior wall of the cooling cavity; 
 the ribs that originate at the first interior wall of the cooling cavity are oriented and sized so that at least some extend a partial way across the distance across the cooling cavity; 
 the ribs that originate at the second interior wall of the cooling cavity are oriented and sized so that at least some extend a partial way across the distance across the cooling cavity; and 
 the ribs that originate on the first interior wall of the cooling cavity and the ribs that originate on the second interior wall of the cooling cavity comprise an alternating arrangement. 
   
     
     
         18 . The turbine blade according to  claim 17 , wherein:
 the ribs that originate at the first interior wall of the cooling cavity are oriented and sized so that at least some extend across at least a majority of the distance across the cooling cavity; and   the ribs that originate at the second interior wall of the cooling cavity are oriented and sized so that at least some extend across at least a majority of the distance across the cooling cavity.   
     
     
         19 . The turbine blade according to  claim 18 , further comprising an airfoil and at least one coolant passage defined within the airfoil, wherein:
 the one or more cooling cavities comprise a pressure side cooling cavity, a suction side cooling cavity, and a coolant chamber, the coolant chamber comprising a chamber that resides substantially between the pressure side cooling cavity and the suction side cooling cavity;   the coolant chamber is in fluid communication with the coolant passage; and   the coolant chamber is in fluid communication with the pressure side cooling cavity and a suction side cooling cavity via a plurality of coolant chamber apertures.   
     
     
         20 . The turbine blade according to  claim 19 , wherein:
 the ribs comprise a plurality of partition ribs, the partition ribs comprising a plurality of outward extending partition ribs and a plurality of inward extending partition ribs;   the outward extending partition ribs originate from a wall defining the coolant chamber and extends outwardly to a position short of an outer wall of the cooling cavity, thus defining a first gap between the outward extending partition rib and the outer wall of the cooling cavity;   the inward extending partition ribs originate from the outer wall of the cooling cavity and extends inwardly to a position short of the wall defining the coolant chamber, thus defining a second gap between the inward extending partition rib and the wall defining the coolant chamber; and   the partition ribs are arranged such the placement of the outward extending partition rib alternates with the placement of the inward extending partition rib.