Gas turbine engine shroud seals

• US 5,988,975 A
• Filed: 10/24/1997
• Issued: 11/23/1999
• Est. Priority Date: 05/20/1996
• Status: Expired due to Term

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Pizzi, Antonio
• Primary Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US08/957,771
• Time in Patent Office: 760 Days
• Field of Search: 415/135, 415/138, 415/139, 415/170.1, 415/173.1, 415/173.3, 415/173.4, 415/173.5, 415/173.6, 415/174.2, 415/174.5, 415/209.2, 415/209.3, 415/115 , 415/116, 415/180, 277/167.5, 277/218, 277/219, 277/236
• US Class Current: 415/139
• 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: F01D 25/246 Fastening of diaphragms or stator-rings
• CPC Class Codes: F05D 2240/11 Shroud seal segments
• CPC Class Codes: F16J 15/0887 the sealing effect being obtained by elastic deformation of the packing

Abstract

A seal assembly for a turbine blade tip shroud including a one-piece bent metallic sheet inter-segment seal having an axial component and a vertical component adapted to fit in a groove formed in the end walls of each shroud segment, wherein the shroud segment has a platform and radially extending ribs, and the seal fits tightly in the groove providing an axial and a radial component to the seal. A ring seal is also provided for sealing a joint between the shroud and a mounting structure where an annular gap is formed having an "L" shaped cross-section, the ring seal having a "C" shaped configuration and one of the legs of the "C" extending within an axial component of the "L" shaped gap. The leg has a wave pattern with the peaks of the wave in contact with opposite radial walls of the axial component of the gap for creating a gas seal at the joint.

Claims

1. A ring seal for a gas turbine engine for sealing a joint between two annular engine parts, the joint between the two parts comprising an annular gap with an axial component, the axial component of the annular gap having opposed radially spaced walls and opposed axially spaced walls, wherein the ring seal has an axially extending portion having a wave pattern with alternating peaks and is adapted to be compressed in the radial direction between the opposed radially spaced walls of the axial component of the annular gap without being compressed in the axial direction between the opposed axially spaced walls of the axial contacts of the annular gap to provide a gas seal at the joint along the radial contacts between the peaks of the ring seal and the opposed radially spaced walls of the axial component of the annular gap.

2. A seal for a gas turbine engine as defined in claim 1, wherein the annular gap further comprises a radial component, the radial component of the annular gap having opposed radially spaced-apart walls, wherein the ring seal further comprises "C" portion having a radial extent less than the opposed radially spaced walls of the radial component of the annular gap to fit within the radial component of the annular gap.

3. The ring seal as defined in claim 2, wherein the ring seal is made from a heat resistant, inherently elastic material.

4. The ring seal as defined in claim 3, wherein the ring seal is made of a bent sheet of heat resistant alloy.

5. The ring seal as defined in claim 2, wherein the radial extent of the "C" portion is greater than the opposed radially spaced walls of the axial component of the annular gap.

7. The ring seal as defined in claim 5, wherein the annular gap further comprises a radial component, the radial component of the annular gap having opposed radially spaced-part walls, wherein the ring seal further comprises a "C" portion having a radial extent less than the opposed radially spaced walls of the radial component of the annular gap to fit within the radial component of the annular gap.

8. The ring seal as defined in claim 7, wherein the radial extent of the "C" portion is greater than the opposed radially spaced walls of the axial component of the annular gap.

6. A ring seal for a turbine blade lip shroud for a gas turbine engine having a hot gas flow path and an outer casing, wherein the shroud is located between the hot gas path and a cooling gas conduit formed between the shroud and the outer casing, the shroud including an axially extending platform engaging a mounting structure within the engine casing to form an annular gap having an axial component between the shroud and the mounting structure, the annular gap having opposed radially spaced walls formed on the shroud and the mounting structure and having opposed axially spaced walls, whereby the ring seal has an axially extending portion having a wave pattern with alternating peaks and is compressed in the radial direction between the opposed radially spaced walls of the axial component of the annular gap without being compressed in the axial direction between the opposed axially spaced walls of the axial component of the annular gap to provide a gas seal at the joint walls between the shroud and the mounting structure along the radial contacts between the peaks of the ring seal and the opposed radially spaced walls of the axial component of the annular gap.