Pre-segmented squealer tip for turbine blades

• US 6,478,537 B2
• Filed: 02/16/2001
• Issued: 11/12/2002
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Westinghouse Power Corporation
• Inventors: Junkin, John Edward
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Kershteyn, Igor
• Application Number:
  US09/785,879
• Publication Number:
  US 20020136638A1
• Time in Patent Office: 634 Days
• Field of Search: 416/224, 416/241.R, 416/241.B, 416/97.R, 416/92, 415/173.1, 415/173.4
• US Class Current: 415/173.1
• CPC Class Codes: B23P 6/002 Repairing turbine components, e.g. moving or stationary blades, rotors, B23P6/045 takes precedence
• CPC Class Codes: F01D 5/20 Specially-shaped blade tips to seal space between tips and stator F01D5/225 takes precedence
• CPC Class Codes: F01D 5/286 Particular treatment of blades, e.g. to increase durability or resistance against corrosion or erosion F01D5/288 takes precedence

Abstract

A turbine blade having a pre-segmented squealer tip is provided. The segment or slots in the squealer tip are located in regions of maximum stress, and reduce cracking of the squealer tip and propagation of cracks into the airfoil. The slots are preferably filled with a corrosion resistant material which is more ductile than the base alloy.

Claims

1. A turbine blade comprising an airfoil, said airfoil comprised of a base alloy and radially extending from a root designed to be fixed on a rotor shaft out to a squealer tip, the squealer tip having one or more slots machined in its end, and wherein said one or more slots are placed substantially at points of maximum stress on the squealer tip, wherein said one or more slots penetrate said squealer tip, said one or more slots extending between an outer surface of the air foil and an interior cavity of said squealer tip.

2. The blade of claim 1, wherein said one or more slots are filled with a highly oxidation and corrosion resistant material which is more ductile than the base alloy.

3. The blade of claim 2, wherein the oxidation and corrosion resistant material is an MCrAlY.

4. The blade of claim 2, wherein a bond is created between said oxidation and corrosion resistant material and said base alloy.

5. The blade of claim 4, wherein said bond is created by spray coating said oxidation and corrosion resistant material on said base alloy.

6. The blade of claim 1, wherein said one or more slots are from about 10 thousandths to 25 thousandths of an inch in width.

7. The blade of claim 1, wherein said one or more slots are about 20 thousandths of an inch in width.

8. The turbine blade of claim 1, wherein the turbine blade is a combustion gas turbine blade.

9. A turbine engine comprising a blade, said blade comprising an airfoil, said airfoil comprised of a base alloy and radially extending from a root designed to be fixed on a rotor shaft out to a squealer tip, the squealer tip having one or more slots machined in its end, and wherein said one or more slots are placed substantially at points of maximum stress on the squealer tip, wherein said one or more slots penetrate said squealer tip, said one or more slots extending between an entry surface of the air foil and an interior cavity of said squealer tip.

10. The turbine engine of claim 9, wherein said one or more slots are filled with a highly oxidation and corrosion resistant material which is more ductile than the base alloy.

11. The turbine engine of claim 10, wherein the oxidation and corrosion resistant material is an MCrAlY.

12. The turbine engine of claim 10, wherein a bond is created between said oxidation and corrosion resistant material and said base alloy.

13. The turbine engine of claim 12, wherein said bond is created by spray coating said oxidation and corrosion resistant material on said base alloy.

14. The turbine engine of claim 9, wherein said one or more slots are from about 10 thousandths to 25 thousandths of an inch in width.

15. The turbine engine of claim 9, wherein said one or more slots are about 20 thousandths of an inch in width.

16. The turbine engine of claim 9, wherein the turbine engine is a combustion gas turbine engine.

17. A power plant incorporating a turbine engine comprising a blade, said blade comprising an airfoil, said airfoil comprised of a base alloy and radially extending from a root designed to be fixed on a rotor shaft out to a squealer tip, the squealer tip having one or more slots machined in its end, and wherein said one or more slots are placed substantially at points of maximum stress on the squealer tip, wherein said one or more slots penetrate said squealer tip, said one or more slots extending between an outer surface of the airfoil and an interior cavity of said squealer tip.