Low stress seal

• US 6,568,692 B2
• Filed: 03/02/2001
• Issued: 05/27/2003
• Est. Priority Date: 03/02/2001
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Kolodziej, Michael J., Hemmele, Raymond
• Primary Examiner(s): Knight, Anthony
• Assistant Examiner(s): Patel, Vishal
• Application Number:
  US09/798,567
• Publication Number:
  US 20020121747A1
• Time in Patent Office: 816 Days
• Field of Search: 277/604, 277/609, 277/614, 277/626, 277/643, 277/644, 277/647, 277/648, 277/500, 277/586, 277/628, 415/135, 415/136, 415/138, 415/139, 415/173.1, 415/173.3, 415/173.5, 415/209.2, 415/209.3
• US Class Current: 277/614
• CPC Class Codes: F01D 11/005 Sealing means between non relatively rotating elements
• CPC Class Codes: F16J 15/0887 the sealing effect being obtained by elastic deformation of the packing

Abstract

A low stress seal seals boundaries between rotor sections of a turbofan engine. The low stress seal includes rounded feet on the ends of legs, which rounded feet cooperate with rounded interior corners within a seal groove. The elimination of sharp interior corners reduces stress and prevents the fatigue failures.

Claims

1. A seal useable between a first section and a second section of a rotating assembly, the sections rotating about a spin axis, the sections having a seal groove with an opening facing inwardly towards the spin axis, the seal groove with a base straddling a boundary between the first section and the second section, the seal comprising:

a curved apex oriented towards the spin axis and curved towards an inside of the seal;

a first leg and a second leg each extending symmetrically away from both the apex and the spin axis on opposing sides of the apex;

a first foot and a second foot that are respectively at ends of the first leg and the second leg, wherein the first foot and the second foot curve toward the inside of the seal;

wherein the first leg and the second leg extend only linearly from the curved apex to the first foot and the second foot when said rotating assembly in a non-operating state; and

wherein the first leg and the second leg curve inward toward the inside of the seal during an operational state.

2. The seal of claim 1 wherein the seal is V shaped.

3. The seal of claim 1, wherein the first foot and the second foot extend inwardly past an area where the first foot and the second foot respectively cooperate with the first seal seat and the second seal seat to seal the seal groove.

4. The seal of claim 3, wherein the first seal seat and the second seal seat are rounded.

5. The seal of claim 4, wherein radii of the first seal seat and the second seal seat are smaller than radii of the first foot and of the second foot.

6. The seal of claim 1, wherein the first foot and the second foot extend away form the base.

7. The seal of claim 6, wherein the seal groove is substantially rectangular.

8. The seal of claim 6, wherein the base is substantially orthogonal to the boundary.

9. The seal of claim 1, wherein the rotating assembly is a rotor of a turbofan engine.

10. A sealing system for sealing a boundary between sections of a rotating assembly, the assembly rotating about a spin axis, the sealing system comprising:

a seal groove having an opening facing inwardly towards the spin axis, the seal groove straddling the boundaries between the sections of the rotating assembly, the seal groove having a first rounded seal seat disposed between a first side and base portion of the seal groove disposed on one side of the boundary, and a second rounded seal seat disposed between a second side and another base portion of the seal groove on a second side of the boundary;

a seal in a V shaped cross-section, the seal having;

a rounded apex radially oriented about the spin axis such that the apex is rounded towards an inside of the seal;

a first leg and a second leg, both of equal lengths and that extend only linearly away from both the rounded apex and the spin axis, when the rotating assembly is in a non-operational state;

wherein the first leg and the second leg curve inward toward the inside of the seal during an operational state; and

a first foot at an end of the first leg and a second foot at the end of the second leg, wherein the first foot and the second foot are rounded inwardly toward the apex, and wherein a first curved surface of the first foot and a second curved surface of the second foot cooperate with the first rounded seal seat and the second rounded seal seat, respectively.

11. The sealing system of claim 10, wherein the rotating assembly includes:

a first volume at a first pressure, and having a surface on which the seal groove is disposed; and

a second volume at a second pressure different from the first pressure, wherein the seal acts to separate the two volumes.

12. The sealing system of claim 11, wherein the first volume is proximal to the spin axis of the rotating assembly, and wherein the second volume is distal from the spin axis of the rotating assembly, and wherein the first pressure is greater than the second pressure.

13. The sealing system of claim 11, wherein the rotating assembly is a rotor assembly of a turbofan engine.

14. The sealing system of claim 11, wherein the first volume is a cooling flow cavity.

15. The sealing system of claim 11, wherein the second volume is a core flow.

16. A method for reducing stress in a seal groove at a boundary between rotors rotating about a spin axis of a turbofan engine, comprising:

providing seal seats with rounded cross-sections, the seal seats being whithin the seal groove straddling the boundary between the rotors, the seal groove opening inwardly towards the spin axis, the seal groove comprising a radial portion and an axial portion of each of said rotors;

providing a V shaped seal having a curved apex that curves towards an inside of the seal, a first leg extending only linearly from one side of the apex during a non-operational state, a second leg extending only linearly from another side of the apex during a non-operational state, rounded feet that extend from ends of the legs, the rounded feet curve inwardly toward the inside of the seal, wherein the feet cooperate with the seal seats to provide a pressure seal, and wherein, the feet cooperate with the seal seats to provide a pressure seal, and wherein, during an operational state, the first leg and the second leg are curved inward toward the inside of the seal; and

inserting the seal into the seal groove with the apex inwardly oriented towards the spin axis.

17. The method of claim 16, wherein said boundary between the rotors in on an outside surface of a cooling flow cavity.

18. A sealing system for sealing a boundary between sections of a rotating assembly, the assembly rotating about a spin axis, the sealing system comprising:

a seal groove having an opening facing inwardly towards the spin axis, the seal groove straddling the boundaries between the sections of the rotating assembly, the seal groove having a first rounded seal seat disposed between a first radial side and a first axial portion of the seal groove disposed on one side of the boundary, and a second rounded seal seat disposed between a second radial side and a second axial portion of the seal groove on a second side of the boundary;

a seal in a V shaped cross-section, the seal having;

a rounded apex radially oriented about the spin axis such that the apex is rounded towards an inside of the seal;

a first leg and a second leg, both of equal lengths and that extend away from both the rounded apex and spin axis;

a first foot at an end of the first leg and a second foot at the end of the second leg, wherein the first foot and the second foot are rounded inwardly toward the apex, whereby a pressure acting on said first leg and said second leg deform said first leg and the second leg inward, the deformation causing a force on the first foot and the second foot, pressing the first foot and the second foot against the first axial portion and the second axial portion, respectively, thereby increasing the surface area between the seal and the seal groove.

19. The sealing system of claim 18, wherein the first leg and the second leg are only linear from the rounded apex toward the first foot and the second foot when the rotating assembly is in a non-operational state.

20. A seal useable between a first section and a second section of a rotor of a turbofan engine, the first section and the second section rotating about a spin axis, the first section and the second having a seal groove with an opening facing inwardly towards the spin axis, the seal groove having a base straddling a boundary between the first section and the second section, the seal groove having a first rounded seal seat disposed between a first radial side and a first axial portion of the seal groove disposed on one side of the boundary, and a second rounded seal seat disposed between a second radial side and a second axial portion of the seal groove on a second side of the boundary, the seal comprising:

a curved apex oriented towards the spin axis and curved towards an inside of the seal;

a first leg and a second leg each extending symmetrically away from both the apex and spin axis on opposing sides of the apex;

a first foot and a second foot that are respectively at ends of the first leg and the second leg, wherein the first foot and the second foot curve toward the inside of the seal;

the first leg and the second leg extending only linearly from the curved apex to the first foot and the second foot when said rotating assembly in a non-operating state;

the first leg and the second leg being curved inward toward the inside of the seal during an operational state;

a curvature of the first foot is the same as a curvature of the second foot;

the first foot is further configured to rest on at least the first axial portion and the first radial side of the seal groove; and

the second foot is further configured to rest on at least the second axial portion and the second radial side of the seal groove.