TURBOMACHINE FAN

Abstract

A ring assembly has a housing made of woven composite material carrying on its radially inner face an acoustic panel with a cellular structure covered with a composite material. The housing includes at least one radial recess in which is engaged at least one radially outwardly projecting part of the radially outer face of the acoustic panel.

Claims

1. A ring assembly of a longitudinal axis for a turbomachine, comprising a housing made of woven composite material carrying on an radially inner face an acoustic panel with a cellular structure covered with a composite material, wherein the housing comprises at least one radial recess in which at least one protruding part projecting radially towards an outside of a radially outer face of the annular acoustic panel is engaged, each projecting portion being formed by a longitudinal rib, and each rib having two side faces connected to each other by a bottom face, said two side faces being flat and inclined relative to each other to converge towards each other in a radially outward direction.

2. The ring assembly of claim 1, wherein each recess has a complementary shape to said at least one protruding part.

3. A ring assembly according to claim 1, wherein the acoustic panel comprises at least three longitudinal ribs evenly distributed around the longitudinal axis.

4. The ring assembly of claim 1, wherein a wear strip is applied to each of the side faces of at least one of the ribs.

5. The ring assembly according to claim 1, wherein a member for connecting the housing to the acoustic panel passes through the housing from the outside and is inserted into each projecting portion of the acoustic panel.

6. The ring assembly according to claim 1, wherein each recess and each protruding part has a uniform cross-section in the longitudinal direction.

7. The ring assembly according to claim 1, wherein the housing is made by weaving carbon fibers and injecting resin.

8. A turbomachine fan comprising the ring assembly according to claim 1 and at least one fan wheel arranged downstream of the annular acoustic panel and surrounded by the housing.

9. A turbomachine comprising the turbomachine fan of claim 8.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0017] FIG. 1 already described above, is a schematic perspective view of a turbomachine according to the prior art;

[0018] FIG. 2, already described above, is a schematic view of an annular acoustic panel arranged at the upstream end of a fan as shown in FIG. 1;

[0019] FIG. 3, already described above, is a schematic in longitudinal section of an acoustic panel showing the means of attachment of the acoustic panel;

[0020] FIG. 4, already described above, is a schematic view of the attachment of the acoustic panel to an outer housing;

[0021] FIG. 5 and

[0022] FIG. 6 are schematic views of the principle of assembly of an acoustic panel with a housing according to the invention;

[0023] FIG. 7 is a schematic view of an acoustic panel for use in an air inlet sleeve according to the invention;

[0024] FIG. 8 is a schematic view of a housing for use in A ring assembly according to the invention,

[0025] FIG. 9 is a larger scale schematic view of the dotted area in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Reference is now made to FIGS. 5 to 8 which show the connection of the acoustic panel 36 and a housing 38 in a ring assembly 39 according to the invention.

[0027] It is thus proposed to make longitudinal or axial recesses 40 on the inner face of the housing 38 which is made by weaving carbon fibres and injecting resin. These longitudinal recesses 40 form grooves with a substantially rectangular cross section. The cross-section of the grooves is substantially constant in longitudinal direction A.

[0028] The acoustic panel 36 comprises an internal honeycomb structure (not shown) similar to that described with reference to the prior art, with cells oriented in the radial direction and covered with a layer of a carbon or glass fiber composite material. The acoustic panel 36 includes protruding parts 42 formed by longitudinal or axial ribs. Each rib 42 has a substantially uniform cross-section from one axial end of the acoustic panel 36 to the other. The cross-section may be substantially rectangular in shape, although it will be noted that the flanks may be inclined as will be discussed below.

[0029] As shown in FIG. 7 and FIG. 8, the ribs 42 may be evenly distributed around the longitudinal axis A and may be three in number as well as the grooves 38 in the housing.

[0030] Thus shaped, the recesses 40 of the housing 38 and the ribs 42 of the acoustic panel 36 have complementary shapes that allow axial engagement of the acoustic panel 36 within the housing 38 by sliding the ribs 42 of the acoustic panel 36 into the grooves 40 of the housing 38.

[0031] As can be seen in FIGS. 5 and 6, each rib 42 comprises two side faces 42a, i.e. two circumferential end faces, each face 42a extending longitudinally. Furthermore, the two side faces 42a of a rib 42 are substantially flat and inclined relative to each other so as to converge towards each other in a radially outward direction. The side faces 42a of a rib 42 are connected to each other by a bottom face 42b. In this configuration, each groove 40 in the housing 38 then has a complementary shape with equally obliquely inclined faces. This conformation allows for easier mounting of the acoustic panel 36.

[0032] To prevent longitudinal movement of the acoustic panel 36 in the housing 38, members 44 are provided for locking the acoustic panel 36 to the housing 38. Thus, a fastener 44 is inserted from the outside of the housing 38 and so as to be inserted into a rib 42 of the acoustic panel 38. Specifically, each fastener 44 extends through the housing 38 and then through the bottom face 42b of a rib 42 and is inserted into the honeycomb structure of the acoustic panel 36. The fastener 44 may be an insert such as a blind rivet.

[0033] Each side face 42a of a rib 42 may be covered with an anti-wear strip to limit wear of the housing 38 due to vibration of the acoustic panel 36, during operation. These anti-wear strips can be made of Teflon for example.

[0034] The connection of the acoustic panel 36 to the housing 38 proposed herein allows the use of a honeycomb structure having a constant thickness in the circumferential direction, which facilitates the manufacture of the acoustic panel 36 as well as its assembly. In addition, the acoustic attenuation achieved by the honeycomb structure is improved.