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US-20260125986-A1 - TURBINE SEALING RING THAT IS REMOVABLE UPSTREAM

US20260125986A1US 20260125986 A1US20260125986 A1US 20260125986A1US-20260125986-A1

Abstract

Turbine for a turbomachine comprising an annular casing ( 1 ), upstream ( 3 ) and downstream ( 4 ) ring supports and a sealing ring ( 2 ) configured to extend around and radially face a blade assembly ( 6 ) of a rotor of the turbine, the supports are mounted against a radially inner surface of the casing ( 1 ), the sealing ring ( 2 ) being configured to be disposed radially between the blade assembly ( 6 ) and the casing ( 1 ), and being mounted against the upstream support and the downstream support, the sealing ring ( 2 ) having a maximum radius with respect to the main axis (X) of the turbine, and the casing ( 1 ) being dimensioned such that the maximum radius of the sealing ring ( 2 ) is strictly smaller than the radius of the upstream end of the casing ( 1 ) so as to allow a mounting by axial insertion, of the sealing ring ( 2 ) and of the upstream ring support ( 3 ), against the downstream ring support ( 4 ).

Inventors

  • PATRICK JEAN LAURENT SULTANA
  • Thierry Fachat
  • Matthieu Simon

Assignees

  • SAFRAN AIRCRAFT ENGINES

Dates

Publication Date
20260507
Application Date
20231016
Priority Date
20221024

Claims (20)

  1. 1 . A turbine for a turbomachine, the turbine having a main axis and comprising an annular casing an upstream ring support, a downstream ring support and a sealing ring, the sealing ring being configured to extend around and radially face a blade assembly of a rotor of the turbine, wherein the upstream ring support and the downstream ring support are mounted against a radially inner surface of the casing, the upstream ring support and the downstream ring support having an upstream end and a downstream end, the sealing ring being configured to be disposed radially between the blade assembly and the casing, and being mounted against the upstream ring support and the downstream ring support, the sealing ring having a maximum radius with respect to the main axis, and the casing being dimensioned such that the maximum radius of the sealing ring is strictly smaller than the radius of the upstream end of the casing so as to allow a mounting by axial insertion, of the sealing ring and of the upstream ring support, against the downstream ring support, the turbine comprising at least one C-shaped locking member configured to hold together in contact, inside the C-shape, an upstream end of the sealing ring and the upstream ring support.
  2. 2 . The turbine for a turbomachine according to claim 1 , wherein the sealing ring comprises a radially protruding portion, the maximum radius of the sealing ring being equal to the maximum radius of the radially protruding portion.
  3. 3 . The turbine for a turbomachine according to claim 2 , comprising at least one seal disposed between the downstream ring support and the radially protruding portion.
  4. 4 . The turbine for a turbomachine according to claim 3 , wherein the at least one seal extends axially.
  5. 5 . The turbine for a turbomachine according to claim 3 , comprising at least one sealing metal sheet disposed between the seal and the downstream ring support.
  6. 6 - 9 . (canceled)
  7. 10 . The turbine for a turbomachine according to claim 3 , comprising at least one sealing metal sheet disposed between the seal and the radially protruding portion.
  8. 11 . The turbine for a turbomachine according to claim 1 , wherein the casing is a low-pressure turbine casing.
  9. 12 . The turbine according to claim 1 , wherein at least one among a downstream end of the sealing ring and a downstream end of the downstream ring support is received in a housing of an external platform of a downstream distributor.
  10. 13 . The turbine according to claim 12 , wherein the housing is a groove into which the at least one end is inserted axially.
  11. 14 . A turbine for a turbomachine, the turbine having a main axis and comprising an annular casing, an upstream ring support, a downstream ring support and a sealing ring, the sealing ring being configured to extend around and radially face a blade assembly of a rotor of the turbine, wherein the upstream ring support and the downstream ring support are mounted against a radially inner surface of the casing, the upstream ring support and the downstream ring support having an upstream end and a downstream end, the sealing ring being configured to be disposed radially between the blade assembly and the casing, and being mounted against the upstream ring support and the downstream ring support, the sealing ring having a maximum radius with respect to the main axis, and the casing being dimensioned such that the maximum radius of the sealing ring is strictly smaller than the radius of the upstream end of the casing so as to allow a mounting by axial insertion, of the sealing ring and of the upstream ring support, against the downstream ring support, at least one C-shaped locking member configured to hold together in contact, inside the C-shape, a downstream end of the sealing ring and the downstream ring support.
  12. 15 . The turbine for a turbomachine according to claim 14 , wherein the sealing ring comprises a radially protruding portion, the maximum radius of the sealing ring being equal to the maximum radius of the radially protruding portion.
  13. 16 . The turbine for a turbomachine according to claim 15 , comprising at least one seal disposed between the downstream ring support and the radially protruding portion.
  14. 17 . The turbine for a turbomachine according to claim 16 , wherein the at least one seal extends axially.
  15. 18 . The turbine for a turbomachine according to claim 16 , comprising at least one sealing metal sheet disposed between the seal and the downstream ring support.
  16. 19 . The turbine for a turbomachine according to claim 16 , comprising at least one sealing metal sheet disposed between the seal and the radially protruding portion.
  17. 20 . The turbine for a turbomachine according to claim 18 , wherein the casing is a low-pressure turbine casing.
  18. 21 . The turbine according to claim 10 , wherein at least one among a downstream end of the sealing ring and a downstream end of the downstream ring support is received in a housing of an external platform of a downstream distributor.
  19. 22 . The turbine according to claim 21 , wherein the housing is a groove into which the at least one end is inserted axially.
  20. 23 . A turbomachine comprising the turbine according to claim 14 .

Description

TECHNICAL FIELD The present disclosure concerns a sealing ring for a turbomachine turbine, particularly a sealing ring for a turbine that can be dismounted from upstream. PRIOR ART The maintenance constraints of turbomachine turbines are known, requiring access to pieces internal to the turbines. For example, the low-pressure turbine blades are generally difficult to access for maintenance operations. In order to facilitate the maintenance, and thus reduce operating costs, turbomachines have been provided with a sealing ring that can be dismounted from upstream. However, the possibility of dismounting the sealing ring from upstream is generally to the detriment of the sealing capacity of the sealing ring, and thus of increased fuel consumption. DISCLOSURE OF THE INVENTION The present disclosure aims to propose a turbine aimed at solving the problems above. To this end, the present disclosure concerns a turbine for a turbomachine, the turbine having a main axis and comprising a casing, typically an annular casing, an upstream ring support, a downstream ring support, a sealing ring, the sealing ring being configured to extend around and radially face a blade assembly of a rotor of the turbine, in which: the upstream ring support and the downstream ring support are mounted against a radially inner surface of the casing, the upstream ring support and the downstream ring support having an upstream end and a downstream end,the sealing ring being configured to be disposed radially between the blade assembly and the casing, and being mounted against the upstream ring support and the downstream ring support,the sealing ring having a maximum radius with respect to the main axis, andthe casing being dimensioned such that the maximum radius of the sealing ring is strictly smaller than the radius of the upstream end of the casing so as to allow a mounting by axial insertion, of the sealing ring and of the upstream ring support, against the downstream ring support. In the present disclosure, the terms “axial”, “radial”, “circumferential”, “internal”, “external” and their derivatives are defined relative to the main axis of the turbomachine; finally, the terms “upstream”, “downstream”, “front” and “rear” are defined relative to the main axis, along the general direction of circulation of the fluid within the turbomachine. By “extends axially, radially or circumferentially” it is meant “extends along a direction having a non-zero component along an axial, radial or circumferential direction”, respectively. A circumferential direction is perpendicular to the axial direction and to a radial direction. The main axis of the turbomachine corresponds to the axis of rotation of the turbomachine. In some embodiments, the upstream ring support is circumferential, preferably over 360°. Preferably, the upstream ring support is continuously mounted bearing against a radially inner surface of the casing, along a circumference. In some embodiments, the downstream ring support is circumferential, preferably over 360°. Preferably, the downstream ring support is sectorized. By upstream ring support and by downstream ring support, it is meant respectively an upstream support, and a downstream support. Such a dimensioning of the sealing ring and of the casing makes it possible, after dismounting the upstream ring support, to dismount the sealing ring by translation along the main axis towards the upstream without the casing being an obstacle. Particularly, the mounting from the front can be carried out without tilting, allowing a more accurate, faster mounting with a reduced risk of damage to pieces. Naturally, unless otherwise stated, any characteristic described relating to a dismounting operation is also applicable to a mounting operation carried out in the reverse order, and vice versa. The dismounting of the sealing ring from upstream thus reduces maintenance time and costs compared to a turbine whose sealing ring can only be dismounted from downstream. The bearing of the sealing ring on the supports ensures the centering of the sealing ring, thus reducing the relative wear of the pieces while being compatible with the dismounting of the sealing ring from upstream. According to one example, the bearing of the sealing ring on the upstream ring support is a radial bearing. According to one example, the bearing of the sealing ring on the downstream ring support is a radial bearing. By radial bearing it is meant a bearing on a surface whose normal has a non-zero radial component. According to one example, the radial bearing has a positive or zero component along the main axis towards the upstream, further facilitating the dismounting from upstream. According to one example, in addition to or as a replacement, the sealing ring has an axial bearing on the upstream ring support. According to one example, the sealing ring has an axial bearing on the downstream ring support. By axial bearing it is meant a bearing on a surface whose normal has a