DEVICE FOR ATTACHING RING SECTORS AROUND A TURBINE ROTOR OF A TURBOMACHINE

Abstract

A device for attaching ring sectors (20) around a turbine rotor (18) in a turbomachine, each of the ring sectors comprising at its upstream end a circumferential rim (44) being able to be held on an annular casing rail (48) by an annular locking member (50), and at its downstream end a part (70) that can press axially against a fixed element (38) of the turbine to prevent the upstream rim (44) of the ring sector (20) from disengaging from the locking member (50) in the event of considerable wear of the rail (48).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and other features, details and advantages of the latter will appear more clearly on reading the following description, given as a nonlimiting example and with reference to the appended drawings in which:

FIG. 1 is a partial schematic view in axial section of a device for attaching ring sectors according to the prior art;

FIG. 2 is a partial schematic view in axial section of a device for attaching ring sectors according to the invention.

Claims

1. A device for attaching ring sectors around a turbine rotor in a turbomachine, each ring sector comprising a frustoconical wall that supports a block of abradable material attached to its inner surface and that comprises at its upstream end a circumferential rim engaged in a radially inner annular groove of an annular casing rail and held radially in this groove by a C-section annular locking member that is engaged axially from upstream on the casing rail and on the circumferential rims of the ring sectors, wherein each ring sector comprises at its downstream end a part that is fitted and attached to the frustoconical wall and to the block of abradable material of the ring sector, this part being able to press axially against a fixed element of the turbine to prevent the upstream rim from disengaging from the wall of the locking member, the axial clearance between the pressing part and the fixed element being less than the axial length of the bearing surface of the upstream rim of the wall on the locking member.

2. The device as claimed in claim 1, wherein the pressing part comprises means that can press radially on the fixed element.

3. The device as claimed in claim 1 or 2, wherein the part is attached to the downstream end of the wall and to the block of abradable material by brazing or welding.

4. The device as claimed in one of the preceding claims, wherein the axial clearance between the pressing part and the fixed element lies between 0.3 and 1.2 mm approximately.

5. The device as claimed in one of the preceding claims, wherein the pressing part has an F-shaped section.

6. The device as claimed in claim 5, wherein the pressing part comprises two rims in a portion of a cylinder that extend in the downstream direction, one of these rims being attached to a radially inner surface of the wall of the ring sector and the other of these rims being able to press radially on a radially outer face of a cylindrical rim of the fixed element.

7. The device as claimed in one of the preceding claims, wherein the fixed element forms part of a turbine guide vane element.

8. A turbomachine, such as an aircraft turbojet or turboprop, which comprises at least one device as claimed in one of the preceding claims.

9. A ring sector for a turbomachine turbine, comprising a frustoconical wall that supports a block of abradable material attached to its inner surface and that comprises at its upstream end a rim for coupling to a casing, which comprises at its downstream end an axial and radial pressing part that is fitted and attached to the wall and to the block of abradable material of the ring sector.

10. The ring sector as claimed in claim 9, wherein the pressing part is attached by welding or brazing to the block of abradable material and to the downstream end of the wall of the ring sector.

11. A turbomachine turbine, which comprises at least one device as claimed in one of claims 1 to 7.