Turbine blade with airfoil tip having cutting tips

Abstract

A turbine blade having a squealer tip at a radially outer end of the turbine blade with a plurality of abradable coating cutting tips extending radially therefrom toward a ring segment is disclosed. During operation, the abradable coating cutting tips may cut into an abradable coating on the ring segments of the turbine engine that are positioned radially outward from the turbine blade. The plurality of abradable coating cutting tips may include one or more cutting arrises extending from the squealer tip to an outermost tip of the at least one of the abradable coating cutting tips.

I claim: 
     
         1 . A turbine blade, comprising:
 a generally elongated blade having a leading edge, a trailing edge, a tip at a first end, a root coupled to the blade at a second end generally opposite the first end for supporting the blade and for coupling the blade to a disc; and   a squealer tip coupled to the tip at the first end, wherein the squealer tip includes a plurality of abradable coating cutting tips that extend radially from the squealer tip toward a ring segment positioned radially outward from the generally elongated blade.   
     
     
         2 . The turbine blade of  claim 1 , wherein the plurality of abradable coating cutting tips is formed into at least two rows of abradable coating cutting tips extending generally orthogonal to a flow of combustion exhaust gases between the squealer tip and the ring segment, and wherein a second row of abradable coating cutting tips is positioned downstream from a first row of abradable coating cutting tips and is offset orthogally to the flow of combustion exhaust gases relative to the first row of abradable coating cutting tips. 
     
     
         3 . The turbine blade of  claim 1 , wherein at least one of the abradable coating cutting tips has at least one cutting arris extending from the squealer tip to an outermost tip of the at least one of the abradable coating cutting tips. 
     
     
         4 . The turbine blade of  claim 3 , wherein at least one of the abradable coating cutting tips has at least three cutting arrises extending from the squealer tip to an outermost tip of the at least one of the abradable coating cutting tips, wherein a first cutting arris is positioned on an upstream side of the at least one of the abradable coating cutting tips, a second cutting arris extending from the squealer tip to the outermost tip of the at least one of the abradable coating cutting tips at a first intersection between the upstream side and a downstream side of the at least one of the abradable coating cutting tips, and a third cutting arris extending from the squealer tip to the outermost tip of the at least one of the abradable coating cutting tips at a second intersection between the upstream side and the downstream side of the at least one of the abradable coating cutting tips, wherein the second intersection is on an opposite side of the tip from a first side. 
     
     
         5 . The turbine blade of  claim 1 , wherein at least one of the plurality of abradable coating cutting tips has a pyramid shape. 
     
     
         6 . The turbine blade of  claim 1 , wherein at least one of the plurality of abradable coating cutting tips extends from the squealer tip a distance of at least 125 microns. 
     
     
         7 . The turbine blade of  claim 1 , wherein at least one of the plurality of abradable coating cutting tips extends from the squealer tip a distance of at least 250 microns. 
     
     
         8 . The turbine blade of  claim 1 , wherein at least one of the plurality of abradable coating cutting tips extends from the squealer tip a distance of up to 1000 microns. 
     
     
         9 . The turbine blade of  claim 1 , wherein of the plurality of abradable coating cutting tips forms a knurled surface on the radially outer end of the squealer tip. 
     
     
         10 . The turbine blade of  claim 1 , wherein at least one of the plurality of abradable coating cutting tips is formed from a plurality of planar surfaces, wherein adjacent planar surfaces intersect to form a cutting arris. 
     
     
         11 . The turbine blade of  claim 10 , wherein the at least one of the plurality of abradable coating cutting tips is formed from at least four planar surfaces. 
     
     
         12 . The turbine blade of  claim 10 , wherein adjacent abradable coating cutting tips are separated at an outer surface of the squealer tip by a linear line. 
     
     
         13 . The turbine blade of  claim 10 , wherein the plurality of abradable coating cutting tips are separated at an outer surface of the squealer tip into rows by a plurality of linear lines positioned in a first orientation and a plurality of linear lines positioned in a second orientation, wherein the second orientation is orthogonal to the first orientation. 
     
     
         14 . The turbine blade of  claim 13 , wherein the first orientation and the second orientation are nonparallel and nonorthogonal relative to a direction of flow of combustion exhaust gases. 
     
     
         15 . A turbine blade, comprising:
 a generally elongated blade having a leading edge, a trailing edge, a tip at a first end, a root coupled to the blade at a second end generally opposite the first end for supporting the blade and for coupling the blade to a disc;   a squealer tip coupled to the tip at the first end, wherein the squealer tip includes a plurality of abradable coating cutting tips that extend radially from the squealer tip toward a ring segment positioned radially outward from the generally elongated blade;   wherein the plurality of abradable coating cutting tips is formed into at least two rows of abradable coating cutting tips extending generally orthogonal to a flow of combustion exhaust gases between the squealer tip and the ring segment, and wherein a second row of abradable coating cutting tips is positioned downstream from a first row of abradable coating cutting tips and is offset orthogally to the flow of combustion exhaust gases relative to the first row of abradable coating cutting tips; and   wherein at least one of the abradable coating cutting tips has at least one cutting arris extending from the squealer tip to an outermost tip of the at least one of the abradable coating cutting tips.   
     
     
         16 . The turbine blade of  claim 15 , wherein at least one of the abradable coating cutting tips has at least three cutting arrises extending from the squealer tip to an outermost tip of the at least one of the abradable coating cutting tips, wherein a first cutting arris is positioned on an upstream side of the at least one of the abradable coating cutting tips, a second cutting arris extending from the squealer tip to the outermost tip of the at least one of the abradable coating cutting tips at a first intersection between the upstream side and a downstream side of the at least one of the abradable coating cutting tips, and a third cutting arris extending from the squealer tip to the outermost tip of the at least one of the abradable coating cutting tips at a second intersection between the upstream side and the downstream side of the at least one of the abradable coating cutting tips, wherein the second intersection is on an opposite side of the tip from the first side. 
     
     
         17 . The turbine blade of  claim 15 , wherein at least one of the plurality of abradable coating cutting tips has a pyramid shape. 
     
     
         18 . The turbine blade of  claim 15 , wherein at least one of the plurality of abradable coating cutting tips extends from the squealer tip a distance of at least 125 microns and less than  1 , 025  microns. 
     
     
         19 . The turbine blade of  claim 1 , wherein of the plurality of abradable coating cutting tips forms a knurled surface on the radially outer end of the squealer tip, wherein at least one of the plurality of abradable coating cutting tips is formed from a plurality of planar surfaces, wherein adjacent planar surfaces intersect to form a cutting arris. 
     
     
         20 . The turbine blade of  claim 19 , wherein the plurality of abradable coating cutting tips are separated at an outer surface of the squealer tip into rows by a plurality of linear lines positioned in a first orientation and a plurality of linear lines positioned in a second orientation, wherein the second orientation is orthogonal to the first orientation, and wherein the first orientation and the second orientation are nonparallel and nonorthogonal relative to a direction of flow of combustion exhaust gases.