Turbomachine exhaust casing and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-11060418-B2
Application number	US-201716301386-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	May 26, 2016
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A casing is provided, for example, an exhaust casing for a turbomachine. The casing generally includes an inner hub having an axis of rotation and an outer annular ferrule extending around the hub, the ferrule configured to define, with the hub, an annular flow path for a gas stream. In some examples, the ferrule is rigidly connected to the hub by arms. The hub generally includes, at one longitudinal end, a scalloped annular flange comprising solid portions distributed at regular intervals about said axis and spaced apart from each other by hollow portions. The hub is produced by assembling several angular hub sectors arranged circumferentially end to end around the axis, each hub sector connected to an adjacent hub sector by a longitudinal weld bead that extends over substantially the entire axial extent of the hub and that is substantially aligned axially with a hollow portion of said flange.

First claim

The invention claimed is:

1. A casing for a turbomachine, comprising:
an inner hub with an axis of revolution; and
an outer annular ferrule extending around the inner hub, the outer annular ferrule configured to define, with the inner hub, an annular flow path for a gas stream, and rigidly connected to the inner hub by arms, the inner hub comprising a scalloped annular flange at a longitudinal end of the inner hub,
the scalloped annular flange extending radially inward with respect to the axis of revolution from a flow path wall of the inner hub, the scalloped annular flange comprising a plurality of solid portions regularly distributed about the axis of revolution and spaced apart from each other by a plurality of hollowed portions,
wherein a radially inner portion of each of the arms is situated between two consecutive solid portions, the radially inner portion of each of the arms defining a perimeter of each of the arms at the flow path wall,
wherein the inner hub is produced by assembling, by welding, several angular hub sectors arranged circumferentially end to end around the axis of revolution, each of the several angular hub sectors connected to an adjacent angular hub sector by a longitudinal weld bead extending over an entire axial extent of the inner hub and aligned with a hollowed portion of the plurality of hollowed portions of the scalloped annular flange.

2. The casing of claim 1 , wherein the number of the several angular hub sectors is equal to the number of arms of the casing.

3. The casing of claim 1 , wherein each of the several angular hub sectors is initially formed from one single part with the radially inner portion of one of the arms.

4. The casing of claim 1 , wherein each arm comprises an upper surface and a lower surface, each longitudinal weld bead extending between the upper surface of a first arm of said arms and the lower surface of a second arm of said arms which is consecutive to the first arm, and each longitudinal weld bead being situated closer to the lower surface of the second arm than the upper surface of the first arm.

5. The casing of claim 1 , wherein the plurality of hollowed portions each comprise a median edge, straight-lined and tangent to a circumference centered on the axis of revolution.

6. The casing of claim 1 , wherein the arms extend into planes, tangent to a circumference centered on the axis of revolution.

7. A turbomachine comprising at least one casing according to claim 1 .

8. A method for manufacturing a casing for a turbomachine, the casing comprising an inner hub and an outer annular ferrule extending around the inner hub and an axis of revolution, the outer annular ferrule configured to define, with the inner hub, an annular flow path for a gas stream and rigidly connected to the inner hub by arms, the inner hub comprising, at a longitudinal end, a scalloped annular flange extending radially inward with respect to the axis of revolution from a flow path wall of the inner hub, the scalloped annular flange comprising a plurality of solid portions regularly distributed about the axis of revolution and spaced apart from each other by a plurality of hollowed portions, wherein a radially inner portion of each of the arms is situated between two consecutive solid portions, the radially inner portion of each of the arms defining a perimeter of each of the arms at the flow path wall, the method comprising:
assembling, by welding, several angular hub sectors arranged circumferentially end to end around the axis of revolution, each of the several angular hub sectors being connected to an adjacent angular hub sector by a longitudinal weld bead extending over an entire axial extent of the inner hub, and aligned with a hollowed portion of the plurality of hollowed portions of the scalloped annular flange.

9. The method of claim 8 , wherein the welding is performed by an electron beam.

10. The method of claim 9 , wherein, to produce each longitudinal weld bead, the electron beam is inclined with respect to the axis of revolution, and is moved into a longitudinal plane passing via the axis of revolution and the longitudinal weld bead to be produced, without passing through a material of the scalloped annular flange.

11. The method of claim 10 , wherein the electron beam is inclined with respect to the axis of revolution radially towards an outside from a downstream longitudinal end towards an upstream longitudinal end of the casing.

12. The method of claim 9 , wherein the electron beam passes directly through successively an edge of the longitudinal weld bead to be welded and an inner annular stiffener of the inner hub.

13. The casing of claim 1 , wherein the several angular hub sectors of the inner hub are produced by casting.

14. The casing of claim 1 , wherein the several angular hub sectors of the inner hub each comprises a flange sector of the scalloped annular flange.

15. The casing of claim 1 , wherein the radially inner portion of each of the arms is situated between a first longitudinal plane passing through the axis of revolution of the inner hub and one of the solid portions of said scalloped annular flange, and a second longitudinal plane passing through the axis of revolution of the inner hub and another consecutive solid portion of the plurality of solid portions.

16. The casing of claim 1 , wherein the radially inner portion of each of the arms is situated halfway from two consecutive solid portions.

17. The casing of claim 1 , wherein the plurality of solid portions and the plurality of hollowed portions are situated in a radial plane which is perpendicular to the axis of revolution of the inner hub.

Assignees

• Safran Aircraft Engines

Inventors

• Debray Benoit Argémiro Matthieu
• Fouquet Dominique Michel
• Ghosarossian-Prillieux Grégory
• Sevi Guillaume
• Sultana Patrick
• Vieillefond Guy

Classifications

• B23K2101/001

  Turbines · CPC title

• F01D25/162

  Bearing supports · CPC title

• F01D25/243 Primary

  Flange connections; Bolting arrangements (F01D25/265 takes precedence) · CPC title

• B23K31/02

  relating to soldering or welding · CPC title

• B23K15/0093

  characterised by the properties of the materials to be welded · CPC title