Rotor and assembly for reducing leakage flow

Abstract

In a rotary machine such as a steam turbine, pressurized fluid flows through a series of stationary and rotary components. Minimizing leakage flow of the fluid enhances the operation and efficiency of the machine. At least one rotor land has a groove formed thereon to generate a vortex as the fluid passes over. The vortex resists the axial flow of the fluid, which reduces the leakage flow.

1 . A rotor for a rotary machine, comprising:
 a plurality of rotor lands spaced apart from each other in an axial direction,   wherein at least one rotor land has a groove formed thereon, and   wherein the groove has a shape that generates a vortex as fluid flows over the rotor so as to resist an axial flow of the fluid.   
     
     
         2 . The rotor of  claim 1 , wherein the shape of the groove formed on at least one rotor land is different from the shape of the groove formed on at least one other rotor land. 
     
     
         3 . The rotor of  claim 1 , wherein a shape of the groove is one of rectangle, square, curve, semi-circle, trapezoid, and triangle. 
     
     
         4 . The rotor of  claim 1 , wherein a bottom of the groove is slanted. 
     
     
         5 . The rotor of  claim 1 , wherein the rotor lands are created in regular intervals. 
     
     
         6 . The rotor of  claim 1 , wherein the rotor lands are created in irregular intervals. 
     
     
         7 . The rotor of  claim 1 , wherein a radial height one rotor land is different from a radial height of at least one other rotor land. 
     
     
         8 . An assembly for a rotary machine, comprising:
 a stator with a plurality of teeth spaced apart from each other in an axial direction; and   a rotor with a plurality of rotor lands spaced apart from each other in the axial direction,   wherein at least one rotor land has a groove formed thereon, and   wherein the groove has a shape that generates a vortex as fluid flows over the rotor so as to resist an axial flow of the fluid.   
     
     
         9 . The assembly of  claim 8 , wherein the shape of the groove formed on one rotor land is different from the shape of the groove formed on at least one other rotor land. 
     
     
         10 . The assembly of  claim 8 , wherein a shape of the groove is one of rectangle, square, curve, semi-circle, trapezoid, and triangle. 
     
     
         11 . The assembly of  claim 8 , wherein a bottom of the groove is slanted. 
     
     
         12 . The assembly of  claim 8 , wherein the rotor lands are created in regular intervals. 
     
     
         13 . The assembly of  claim 8 , wherein the rotor lands are created in irregular intervals. 
     
     
         14 . The assembly of  claim 8 , wherein a pitch of the rotor lands is adjusted based on a minimum clearance between the rotor lands and the stator teeth. 
     
     
         15 . The assembly of  claim 8 , wherein a radial height one rotor land is different from a radial height of at least one other rotor land. 
     
     
         16 . The assembly of  claim 8 , wherein at least one stator tooth is slanted. 
     
     
         17 . The assembly of  claim 8 , wherein at least one rotor land is aligned with a corresponding stator tooth such that a tip of the corresponding stator tooth vertically overlaps an axial width of the rotor land. 
     
     
         18 . The assembly of  claim 17 , wherein at least rotor land is not aligned with any stator tooth. 
     
     
         19 . The assembly of  claim 18 , wherein at least one stator tooth is not aligned with any rotor land. 
     
     
         20 . The assembly of  claim 8 , wherein the rotary machine is a steam turbine and the assembly is an end-packing seal assembly of the steam turbine.