Sealing of turbine engine enclosures produced by brush seal and labyrinth

Patent metadata

Field	Value
Publication number	US-9879607-B2
Application number	US-201314095072-A
Country	US
Kind code	B2
Filing date	Dec 3, 2013
Priority date	Dec 5, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A sealing device for an enclosure of a turbine engine formed by an assembly of juxtaposed rotating and/or static bodies is provided. The sealing device includes at least one brush seal having a brush body, carried by at least one first member, and bristles extending from the brush body and arranged so as to rub against at least one second member rotatable relative to the first member, so as to produce a pressure difference between the inside of said enclosure and its outer environment. The device further includes a labyrinth-type seal, the labyrinth being positioned in series with the brush seal between the inside of the enclosure and its outer environment.

First claim

The invention claimed is:

1. A sealing device for an enclosure for lubricating bearings of a rotating shaft of a turbine engine formed by an assembly of at least one of juxtaposed rotating or static bodies, the sealing device comprising:
a brush seal having a brush body, carried by a first member, and bristles extending from said brush body and arranged so as to rub against a second member rotatable relative to the first member, so as to produce a pressure difference between an inside of said enclosure and an outer environment thereof; and
a labyrinth-type seal having at least one knife-edge seal extending from said first or second member and cooperating with an abradable material carried respectively by said second or first member, said labyrinth seal being positioned in series with said brush seal between the inside of said enclosure and the outer environment thereof,
wherein a leakage flow of gases passes through said sealing device,
wherein the labyrinth seal is provided entirely on a side positioned upstream the leakage flow and having a higher pressure between the inside of said enclosure and the outer environment of said enclosure, and
wherein said labyrinth seal is provided upstream said brush seal, the at least one knife-edge seal of the labyrinth seal being provided so as to provide a pressure drop downstream said labyrinth seal, to reduce the effort and flexion to which said bristles of said brush seal are subjected, thereby causing said brush seal to operate at maximum efficiency, thereby producing sealing at all speeds of the shaft,
wherein the first member is a fixed cylindrical wall delimiting a fixed portion of the enclosure, the second member is a high-pressure shaft connected to a high-pressure compressor and a high-pressure turbine, and the knife-edge seal extends from the high-pressure shaft, and the abradable material is carried by the fixed cylindrical wall,
wherein said fixed cylindrical wall has a boring within which the brush body is positioned, and an axial extension forming a circular crown carrying said abradable material, an inner diameter of the boring being greater than an inner diameter of the crown,
wherein the high-pressure shaft includes a cylindrical face positioned facing the bristles of said brush seal and extending axially in order to carry the knife-edge seal of the labyrinth seal at a free end of the high-pressure shaft,
wherein a zone having an intermediate pressure is provided between the labyrinth seal and the brush seal, the intermediate pressure being greater than a pressure of the enclosure and less than a pressure of the outer environment of the enclosure, and
wherein a outer diameter of the high-pressure shaft in the zone having the intermediate pressure is equal to an outer diameter of the cylindrical face of the high-pressure facing the bristles of said brush seal and is equal to an outer diameter of the high-pressure shaft in a section of the enclosure adjacent to the brush seal.

2. The device according to claim 1 , wherein the brush seal is a seal with carbon bristles.

3. The device according to claim 1 , wherein the labyrinth seal has only one knife-edge seal.

4. A turbine engine comprising:
at least one enclosure for lubricating bearings of a rotating shaft thereof, wherein the sealing of said enclosure against an environment thereof is ensured by at least one a sealing device formed by an assembly of at least one of juxtaposed rotating or static bodies, the sealing device comprising:
a brush seal having a brush body, carried by a first member, and bristles extending from said brush body and arranged so as to rub against a second member rotatable relative to the first member, so as to produce a pressure difference between an inside of said enclosure and an outer environment thereof; and
a labyrinth-type seal having at least one knife-edge seal extending from said first or second member and cooperating with an abradable material carried respectively by said second or first member, said labyrinth seal being positioned in series with said brush seal between the inside of said enclosure and the outer environment thereof,

wherein a leakage flow of gases passes through said sealing device,
wherein the labyrinth seal is provided entirely on a side positioned upstream the leakage flow and having a higher pressure between the inside of said enclosure and the outer environment of said enclosure,
wherein said labyrinth seal is provided upstream said brush seal, the at least one knife-edge seal of the labyrinth seal being provided so as to provide a pressure drop downstream said labyrinth seal, to reduce the effort and flexion to which said bristles of said brush seal are subjected, thereby causing said brush seal to operate at maximum efficiency, thereby producing sealing at all speeds of the shaft,
wherein the first member is a fixed cylindrical wall delimiting a fixed portion of the enclosure, the second member is a high-pressure shaft connected to a high-pressure compressor and a high-pressure turbine, and the knife-edge seal extends from the high-pressure shaft, and the abradable material is carried by the fixed cylindrical wall,
wherein said fixed cylindrical wall has a boring within which the brush body is positioned, and an axial extension forming a circular crown carrying said abradable material, an inner diameter of the boring being greater than an inner diameter of the crown,
wherein the high-pressure shaft includes a cylindrical face positioned facing the bristles of said brush seal and extending axially in order to carry the knife-edge seal of the labyrinth seal at a free end of the high-pressure shaft,
wherein a zone having an intermediate pressure is provided between the labyrinth seal and the brush seal, the intermediate pressure being greater than a pressure of the enclosure and less than a pressure of the outer environment of the enclosure, and
wherein a outer diameter of the high-pressure shaft in the zone having the intermediate pressure is equal to an outer diameter of the cylindrical face of the high-pressure facing the bristles of said brush seal and is equal to an outer diameter of the high-pressure shaft in a section of the enclosure adjacent to the brush seal.

5. The turbine engine according to claim 4 , wherein the brush seal is a seal with carbon bristles.

6. The turbine engine according to claim 4 , wherein the labyrinth seal has only one knife-edge seal.

7. The turbine engine according to claim 4 , wherein the leakage flow of gases is provided by a compressor of the turbine engine.

8. The turbine engine according to claim 4 , comprising an upstream enclosure and a downstream enclosure for lubricating bearings of a rotating shaft thereof, wherein the sealing of each of the enclosures is ensured by a sealing device.

9. The device according to claim 1 , further comprising a plate which holds a brush body of the brush seal in place, and a lock ring which holds the plate in place, the lock ring being housed in a groove provided in the boring.

10. The device according to claim 9 , wherein the brush body is an annular torus constituted of several sectors.

Assignees

• Snecma

Inventors

• Brunet Antoine Robert Alain
• Leroux Delphine
• Aouizerate Gilles

Classifications

• F01D11/00 Primary

  Preventing or minimising internal leakage of working-fluid, e.g. between stages (sealings in general F16J {; sealing arrangements for transition ducts of combustor cans F01D9/023}) · CPC title

• F02C7/28 Primary

  Arrangement of seals · CPC title

• F01D11/02

  by non-contact sealings, e.g. of labyrinth type (for sealing space between rotor blade tips and stator F01D11/08) · CPC title

• F16J15/3288

  Filamentary structures, e.g. brush seals · CPC title

• F05D2240/56

  Brush seals · CPC title