Turbine stage for a turbine engine

Patent metadata

Field	Value
Publication number	US-9957841-B2
Application number	US-201314394355-A
Country	US
Kind code	B2
Filing date	Apr 17, 2013
Priority date	Apr 20, 2012
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A turbine stage for a turbine engine, the stage including a nozzle and a wheel mounted inside a sectorized ring carried by a casing. The nozzle is attached to the casing and is retained axially downstream by bearing against an annular split ring. Each ring sector includes at its upstream end a member of C-shaped section that is engaged on the casing rail and that holds the split ring radially. A radially inner wall of the C-shaped member of each ring sector extends inside the split ring over an entire axial dimension thereof and its upstream end portion is engaged in at least one recess of the nozzle.

First claim

The invention claimed is:

1. A turbine stage for a turbine engine, the stage comprising:
a stationary nozzle and a wheel mounted downstream from the nozzle and inside an annular casing,
the nozzle being attached to the casing and being retained axially downstream by bearing against an annular split ring mounted in an annular groove of a rail of the casing,
the wheel being mounted inside a sectorized ring carried by the casing, the sectorized ring including a plurality of ring sectors, each ring sector including, at an upstream end thereof, a C-shaped member that is engaged on the casing rail and that holds the split ring radially in the groove,
a radially inner wall of the C-shaped member of each ring sector extends inside the split ring over an entire axial dimension thereof, and an upstream end portion of the radially inner wall of the C-shaped member of each ring sector is engaged inside and enclosed by a first recess and a second recess of the nozzle,
an upstream circumferential edge of the radially inner wall of the C-shaped member of each ring sector including at least one notch co-operating with complementary means of the nozzle to prevent each ring sector from moving in rotation relative to the nozzle,
wherein the nozzle includes a radially outer annular tab at a downstream end thereof, the tab including an outer cylindrical surface for bearing radially against the casing rail and a downstream radial surface for bearing against the split ring, the first recess and the second recess being formed in the tab and opening out downstream in the downstream radial surface, and
wherein the first recess and the second recess are separated from each other by an axial extra thickness of the tab, a first circumferential end of the first recess and a first circumferential end of the second recess being closed by the axial extra thickness of the tab, a second circumferential end of the first recess being closed by a first web of material of the tab extending axially downstream, a second circumferential end of the second recess being closed by a second web of material of the tab extending axially downstream, and the first recess being circumferentially longer than the second recess.

2. The stage according to claim 1 , wherein the complementary means of the nozzle includes the extra axial thickness of the tab.

3. The stage according to claim 1 , wherein the axial dimension of the radially inner wall of the C-shaped member of each ring sector is greater than an axial dimension of a radially outer wall of the C-shaped member of each ring sector.

4. The stage according to claim 1 , wherein facing lateral edges of annular tab sectors of the nozzle sectors include rectilinear slots for receiving sealing strips that extend radially outwards towards at least one of the casing rail and the split ring, the rectilinear slots extending in a plane situated upstream from the first recess and the second recess, or extending at least in part in the side webs of the nozzle sectors.

5. The stage according to claim 1 , wherein the upstream end portion of the radially inner wall of the C-shaped member of each ring sector is spaced apart from a radial wall of the first recess of the nozzle by an axial clearance, and from an outer cylindrical wall of the first recess by a radial clearance.

6. A turbine engine comprising at least one turbine stage according to claim 1 .

7. The stage according to claim 1 , wherein the at least one notch of the upstream circumferential edge of the radially inner wall of the C-shaped member of each ring sector defines a first upstream end portion of the radially inner wall of the C-shaped member of each ring sector and a second upstream end portion of the radially inner wall of the C-shaped member of each ring sector, and the first upstream end portion of the radially inner wall of the C-shaped member of each ring sector is engaged inside and enclosed by the first recess, and the second upstream end portion of the radially inner wall of the C-shaped member of each ring sector is engaged and enclosed by the second recess.

8. The stage according to claim 1 , wherein the first recess extends over more than half of a circumferential dimension of the nozzle.

Assignees

• Snecma

Inventors

• Gendraud Alain Dominique
• Martin-Matos Alberto
• Millier Vincent
• Prestel Sebastien Jean Laurent

Classifications

• F05D2230/60

  Assembly methods · CPC title

• F01D9/042

  fixing blades to stators (fixing stator-rings in the casing or to each other F01D25/246) · CPC title

• F05D2240/91

  on a stationary structure · CPC title

• F01D9/041

  using blades (F01D5/148 takes precedence) · CPC title

• F01D11/005

  Sealing means between non relatively rotating elements · CPC title