Apparatus and method for preventing leakage of cooling air in a shroud assembly of a gas turbine engine

• US 5,188,506 A
• Filed: 08/28/1991
• Issued: 02/23/1993
• Est. Priority Date: 08/28/1991
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Creevy, Clifford S., Eckert, Terry T.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US07/750,991
• Time in Patent Office: 545 Days
• Field of Search: 415/115, 415/116, 415/173.1, 415/173.3, 415/174.2, 277/168, 277/169, 277/173, 277/177, 277/206 R, 285/918, 251/900, 29/888.3, 29/889.22
• US Class Current: 415/115
• CPC Class Codes: F01D 11/005 Sealing means between non relatively rotating elements
• CPC Class Codes: F01D 11/08 for sealing space between rotor blade tips and stator specially-shaped blade tips therefor F01D5/20
• CPC Class Codes: Y10T 29/49297 Seal or packing making
• CPC Class Codes: Y10T 29/49323 Assembling fluid flow directing devices, e.g., stators, diaphragms, nozzles

Abstract

An assembly for preventing cooling air from leaking from a plenum region formed by a shroud support and a shroud. The shroud support and shroud being so connected as to form a gap which leads from the plenum region to a cavity. The cavity being located in the forward hook region of the shroud support. A rope seal fills the cavity and prevents cooling air from leaking into the cavity causing the cooling air to remain in the plenum region.

Claims

1. An assembly for preventing leakage of cooling air from a plenum region located in a gas turbine engine, said assembly comprising:

a shroud support;

a shroud connected to said shroud support so as to form the plenum region and a cavity, and wherein said shroud support and said shroud are so connected that a gap extends form the plenum region to said cavity;

sealing means for preventing the leakage of cooling air from the plenum region to the cavity, said sealing means contacting said shroud support and said shroud;

wherein said sealing means causes the cooling air to be directed from the plenum through a plurality of film holes which extend through an axially extending mid-section region of said shroud which result sin an interior of said shroud being convectively cooled;

wherein each of said film holes have an inlet at a radially outward and radially facing surface of said shroud which forms a portion of a boundary of the plenum and an outlet at a radially inward and radially facing surface of said shroud adjacent a gas path of the gas turbine engine; and

wherein said shroud includes a forward region, said forward region including a radially inner portion and a radially outer portion forming an axially extending groove therebetween, said groove engaging a forward hook of said shroud support, said radially outer portion including a forward facing step for accepting said sealing means, said step being radially outward of said groove.

2. An assembly according to claim 1 wherein a forward foot region of said shroud support and a forward foot region of said shroud form the gap.

3. An assembly according to claim 2 wherein said shroud has a cavity wall region comprising said forward facing step and said shroud support has a cavity wall region, said sealing means contacting the cavity wall region of said shroud and the cavity wall region of said shroud support.

4. An assembly according to claim 3 wherein said sealing means is selected from the class including rope seals, C seals, and E seals.

5. An assembly for preventing leakage of cooling air from an annular plenum region located in a gas turbine engine, said assembly comprising:

a plurality of circumferentially connected shroud supports;

a plurality of circumferentially connected shrouds which are connected to said plurality of shroud supports so as to form the annular plenum region and an annular gap, and wherein said plurality of shrouds are so connected that said annular gap extends form the annular plenum region to an annular cavity;

sealing means for preventing the leakage of cooling air form the annular plenum region to the annular cavity, said sealing means contacting the plurality of shroud supports and the plurality of shrouds;

wherein said sealing means causes the cooling air to be directed from the annular plenum region through a plurality of film holes in each of said shrouds, said film holes extending through an axially extending mid-section region of each of said shrouds which results in an interior of each of said shrouds being convectively cooled;

wherein each of said film holes have an inlet at a radially outward and radially facing surface of one of said shrouds, said outward surface forming a portion of a boundary of the annular plenum region, and an outlet at a radially inward and radially facing surface of said one of said shrouds, said inward surface being adjacent a gas path of the gas turbine engine; and

wherein each of said shrouds includes a forward region, said forward region including a radially inner portion and a radially outer portion forming an axially extending groove therebetween, said groove engaging a forward hook of one of said shroud supports, said radially outer portion including a forward facing step for accepting said sealing means, said step being radially outward of said groove.

6. An assembly according to claim 5 wherein said sealing means is selected form the class comprising rope seals, C seals, and E seals.

7. A method of assembling a gas turbine engine, the gas turbine engine including a plurality of circumferentially connected shroud supports which are connected to a plurality of circumferentially connected shrouds, the plurality of shroud supports and the plurality of shrouds forming an annular plenum for accommodating cooling air, the plurality of shroud supports and the plurality of shrouds being so connected that an annular gap extends form the annular plenum to an annular cavity, each of the shrouds having a plurality of film holes extending through an axially extending mid-section region of the shroud, each of the film holes having an inlet at a radially outward and radially facing surface of the shroud which forms a portion of a boundary of the annular plenum and an outlet at a radially inward and radially facing surface of the shroud adjacent a gas path of the gas turbine engine, each of the shrouds including a forward region, said forward region including a radially inner portion and a radially outer portion forming an axially extending groove therebetween, said groove engaging a forward hook of one of the plurality of shroud supports, the method comprising the steps of:

forming a forward facing step in the radially outer portion of each of the shrouds, at a location radially outward of the groove, for creating a portion of the annular cavity;

filling the annular cavity with a sealing means for preventing the cooling air for leaking from the annular plenum to the annular cavity; and

causing the cooling air to be directed form the annular plenum through the plurality of film holes for convectively cooling an interior of each of the shrouds.

8. A method of assembling according to claim 7 wherein the sealing means is selected from the class including rope seals, C seals, and E seals.