Blade assembly in a combustion turbo-machine providing reduced concentration of mechanical stress and a seal between adjacent assemblies

• US 7,762,780 B2
• Filed: 01/25/2007
• Issued: 07/27/2010
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Decardenas, Rafael A.
• Primary Examiner(s): EDGAR, RICHARD A
• Application Number:
  US11/698,233
• Publication Number:
  US 20080181779A1
• Time in Patent Office: 1,279 Days
• Field of Search: 416/500, 416/190, 416/193.A, 416/191, 416/248, 415/139, 415/134
• US Class Current: 416/193.00A
• CPC Class Codes: F01D 11/006 Sealing the gap between rotor blades or blades and rotor
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F01D 5/22 Blade-to-blade connections, e.g. for damping vibrations
• CPC Class Codes: F05D 2250/14 elliptical
• CPC Class Codes: F05D 2250/71 curved
• CPC Class Codes: F05D 2260/94 Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
• CPC Class Codes: Y10S 416/50 Vibration damping features

Abstract

A blade assembly 100 (FIG. 5) configuration that includes a means for distributing mechanical stress (e.g., a stress dissipater 54) is provided. The stress dissipater is configured to reduce the concentration of a peak mechanical stress without compromising the effectiveness of a seal between adjacent rotating blade assemblies.

Claims

1. A blade assembly in a turbo-machine, the assembly comprising:

a blade comprising a platform with a surface;

a groove formed in said surface, the groove configured to linearly extend along a groove axis in a direction generally along an axis of rotation of the turbo-machine, the groove positioned to extend between adjacent blade assemblies of a common row of blades of the turbo-machine, the groove adapted to receive a cylindrical seal pin having a circular cross-section along the groove axis, the seal pin further having at least one end proximate a corresponding end of the groove, the seal pin operable to make sealing contact with a corresponding surface of an adjacent blade assembly to avoid leakage of a fluid through a gap there between, wherein the end of the groove comprises a first portion comprising a blocking surface generally normal to the axis of rotation, the blocking surface adjacent to the end of the seal pin, and the end of the groove further comprises a second portion comprising a lengthwise extension of the groove beyond the blocking surface; and

a dam disposed between the groove end and the lengthwise extension of the groove, the dam configured to radially extend from a bottom location at the end of the groove, the dam positioned substantially normal relative to the groove axis into a portion of the lengthwise extension of the groove, the dam constructed as an integral structure of the blade platform.

2. The blade assembly of claim 1, wherein said first portion of the end of the groove comprises a radially inner portion with respect to a rotor axis, and said second portion of the end of the groove comprises a radially outer portion with respect to the first portion.

3. The blade assembly of claim 1, wherein said lengthwise extension of the groove comprises a fillet configured to extend over a segment encompassing at least half a width of the groove.

4. A blade in a turbo-machine comprising:

a groove formed in a platform section of the blade, the groove configured to linearly extend along a groove axis in a direction generally along an axis of rotation of the turbo-machine, the groove positioned to extend between adjacent blade assemblies of a common row of blades of the turbo-machine, the groove adapted to receive a cylindrical seal pin having a circular cross-section along the groove axis, the seal pin operable to make a sealing contact with an adjacent blade platform to avoid leakage of a fluid through a gap there between, wherein at least one end of the groove comprises a first portion comprising a mechanical stress dissipater having a surface configured to distribute mechanical stresses there through, and wherein the end of the groove further comprises a second portion comprising a blocking structure having a fluid-deflecting surface positioned to impede a flow of fluid around the end of the seal pin, wherein the fluid-deflecting surface is positioned generally normal to the axis of rotation of the turbo-machine, and wherein the surface for distributing mechanical stress is arranged to provide a transition from a surface disposed in the direction generally along the axis of rotation of the turbo-machine to a surface generally normal to the axis of rotation of the turbo-machine.

5. The blade assembly of claim 4, wherein said first portion of the end of the groove comprises a radially inner portion with respect to a rotor axis, and said second portion of the end of the groove comprises a radially outer portion with respect to the first portion.

6. The blade assembly of claim 4 wherein the surface for distributing mechanical stress comprises an elliptically-shaped structure.

7. The blade assembly of claim 4 wherein the surface for distributing mechanical stress is configured to extend over a segment encompassing at least half a width of the groove.

8. A blade group in a turbo-machine comprising:

a first blade comprising a first platform with a first surface;

a second blade comprising a second platform with a second surface located adjacent said first surface and forming a gap there between;

a groove formed in said first surface, the groove comprising a length and width in a plane of the first surface, the groove configured to linearly extend along a groove axis in a direction generally along an axis of rotation of the turbo-machine;

a cylindrical seal pin disposed in the groove, said seal pin having a circular cross-section along the groove axis, the seal pin having a first end proximate a first end of the groove and a second end proximate a second end of the groove, said seal pin operable to make sealing contact with the second surface to avoid leakage of a fluid through the gap, wherein each end of the groove comprises a first portion comprising a blocking surface generally normal to the groove axis, the blocking surface adjacent to each respective end of the seal pin, and each end of the groove further comprises a second portion comprising a lengthwise extension of the groove beyond the blocking surface; and

a dam disposed between the groove and the lengthwise extension of the groove, the dam configured to radially extend from a bottom location at the end of the groove, the dam positioned substantially normal relative to the groove axis into a portion of the lengthwise extension of the groove, the dam constructed as an integral structure of the blade platform.

9. The blade group of claim 8, wherein said first portion of the end of the groove comprises a radially inner portion with respect to a rotor axis, and said second portion of the end of the groove comprises a radially outer portion with respect to the first portion.

10. The blade group of claim 8, wherein said lengthwise extension of the groove comprises a fillet configured to extend over a segment encompassing at least half a width of the groove.

11. A blade assembly in a turbo-machine comprising:

a blade having a platform section; and

at least one groove formed in a surface of said platform section, the groove configured to linearly extend along a groove axis in a direction generally along an axis of rotation of the turbo-machine, the groove positioned to extend between adjacent blade assemblies in a common row of blades of the turbo-machine, the groove adapted to receive a cylindrical seal pin having a circular cross-section along the groove axis, the seal pin having at least one end proximate a corresponding end of the groove, said seal pin operable to make sealing contact with an adjacent platform section to avoid leakage of a fluid through a gap there between, wherein a first portion of said end of the groove comprises a mechanical stress dissipater comprising a curved surface for dissipating a peak mechanical stress there through by a pre-determined factor wherein a second portion of said at least one end of the groove comprises a fluid-deflecting surface positioned to impede the flow of fluid around the end of the seal pin, wherein the fluid-deflecting surface is positioned generally normal to the axis of rotation of turbo-machine, and wherein the curved surface is arranged to provide a transition from a surface disposed in the direction generally along the axis of rotation of the turbo-machine to a surface generally normal to the axis of rotation of the turbo-machine.

12. The blade assembly of claim 11 wherein the predetermined factor ranges from about 0.4 to about 0.8.