Reduced-stress compressor blisk flowpath

• US 6,511,294 B1
• Filed: 09/23/1999
• Issued: 01/28/2003
• Est. Priority Date: 09/23/1999
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Smith, Paul M., Bulman, David E., Rhoda, James E., Egan, Lawrence J., Zylka, Richard P., Burns, Craig P., Suffoletta, Daniel G., Mielke, Mark J., Ballman, Steven M.
• Primary Examiner(s): Ryznic, John E.
• Application Number:
  US09/405,308
• Time in Patent Office: 1,223 Days
• Field of Search: 416/193.A, 416/193.R, 416/248, 416/219.R
• US Class Current: 416/193.00A
• CPC Class Codes: F01D 5/02 Blade-carrying members, e.g. rotors rotors of non-bladed type F01D1/34; stators F01D9/00 ; selecting particular materials F01D5/28
• CPC Class Codes: F01D 5/06 Rotors for more than one axial stage, e.g. of drum or multiple disc type; Details thereof, e.g. shafts, shaft connections F01D5/022, F01D5/023 take precedence
• CPC Class Codes: F01D 5/143 Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour
• CPC Class Codes: F04D 29/321 for axial flow compressors
• CPC Class Codes: F05D 2250/70 Shape

Abstract

A gas turbine engine rotor assembly including a rotor having a radially outer rim with an outer surface shaped to reduce circumferential rim stress concentration between each blade and the rim. Additionally, the shape of the outer surface directs air flow away from an interface between a blade and the rim to reduce aerodynamic performance losses between the rim and blades. In an exemplary embodiment, the outer surface of the rim has a concave shape between adjacent blades with apexes located at interfaces between the blades and the rim.

Claims

1. A method of reducing circumferential rim stress concentration in a gas turbine engine, the engine including a rotor including a radially outer rim, a radially inner hub, and a web extending therebetween, a plurality of circumferentially spaced apart rotor blades extending radially outwardly from the rim, said method comprising the step of:

providing an outer surface of the outer rim with a shape including a compound radius that defines at least one apex within the outer rim outer surface, and that reduces circumferential rim stress concentration between each of the blades and the rim; and

operating the gas turbine engine such that airflow is directed over the outer rim outer surface.

2. A method in accordance with claim 1 wherein said step of providing an outer surface of the outer rim comprises the step of providing the outer surface of the outer rim with a concave compound radius.

3. A method in accordance with claim 2 wherein said step of providing the outer surface of the outer rim with a compound radius further comprises the step of providing a first radius between approximately 0.04 inches and 0.5 inches.

4. A method in accordance with claim 3 wherein said step of providing the outer surface of the outer rim with a compound radius further comprises the step of providing a second radius approximately 2 to 10 times a distance between said circumferentially spaced apart rotor blades.

5. A method in accordance with claim 1 wherein said step of providing an outer surface of the outer rim further comprises the step of casting a rim to include a rim surface having a shape including a compound radius.

6. A method in accordance with claim 1 wherein said step of providing an outer surface of the outer rim further comprises the step of machining a rim to produce a rim surface having a shape including a compound radius.

7. A method in accordance with claim 1 wherein said step of providing an outer surface of the outer rim further comprises the step of securing the blades to the rim by fillet welds or friction welds to produce a rim surface having a shape including a compound radius.

8. A method in accordance with claim 1 wherein the outer rim includes an inner surface, said method comprising the step of:

providing an inner surface of the outer rim with a shape that defines at least one apex within the outer rim, and that reduces circumferential rim stress concentration between each of the blades and the rim.

9. A gas turbine engine rotor assembly comprising a rotor comprising a radially outer rim, a radially inner hub, and a web extending therebetween, a plurality of circumferentially spaced apart rotor blades extending radially outwardly from said rim, an outer surface of said outer rim having a shape including a compound radius which defines at least one apex within said outer rim outer surface, and which reduces circumferential rim stress concentration between each of said blades and said rim.

10. A gas turbine engine rotor assembly in accordance with claim 9 wherein said outer rim surface has a circumferentially concave shape between adjacent blades.

11. A gas turbine engine in accordance with claim 9 wherein said rotor comprises a plurality of blisks.

12. A gas turbine engine in accordance with claim 9 wherein said outer rim shape directs air flow away from an interface between each of said blades and said rim.

13. A gas turbine engine in accordance with claim 9 wherein said outer surface of said outer rim comprises a compound radius.

14. A gas turbine engine in accordance with claim 13 wherein said compound radius comprises a first radius and a second radius, said first radius is between approximately 0.04 inches and 0.5 inches.

15. A gas turbine engine in accordance with claim 13 wherein said second radius is approximately 2 to 10 times a distance between said circumferentially spaced apart rotor blades.

16. A gas turbine engine rotor assembly comprising a first rotor and a second rotor, said first rotor coupled to said second rotor, at least one of said rotor comprising a radially outer rim, a radially inner hub, and a web extending therebetween, a plurality of circumferentially spaced apart rotor blades extending radially outwardly from said rim, an outer surface of said outer rim comprising a compound radius which reduces circumferential rim stress concentration between each of said blades and said rim.

17. A gas turbine engine rotor assembly in accordance with claim 16 wherein said outer rim surface of said one rotor has a concave shape between adjacent blades.

18. A gas turbine engine in accordance with claim 16 wherein said at least one of said rotor comprises a plurality of blisks.

19. A gas turbine engine in accordance with claim 16 wherein said outer surface of said outer rim comprises a first radius and a second radius.

20. A gas turbine engine in accordance with claim 19 wherein said first radius is between approximately 0.04 inches and 0.5 inches, said second radius is approximately 2 to 10 times a distance between said circumferentially spaced apart rotor blades.