The subject of the invention is a turbine engine vane of the type comprising a plate added onto a main structural part of the vane and which can be used in particular for outlet guide vanes (OGV).
An example of such vanes is given in the document EP-A-1 557 529. A cavity is hollowed out in the centre of the main part, and the plate makes it possible to cover it. Ribs borne by the main part extend nevertheless into the cavity and divide its volume. The plate rests on the ribs when it is mounted, which supports it. The document US-A-2010/0247322, which describes an analogous device, may also be cited.
Various methods are used to join the plate to the main part. In the document cited in the latter, friction welding is proposed. Other methods of welding or bonding may also be practiced; but whatever the method used, a leak proof sealing of the cavity consecutive to the assembly is not guaranteed, since the layer of binder installed between the main part and the plate may be rendered discontinuous accidentally, during the coating of the binder or during the assembly method. Another difficulty to overcome is that it is necessary to ensure that the plate is perfectly placed on the main part and that it remains so during the assembly method.
The invention has been conceived to overcome these drawbacks, and it stands out by an excellent precision of position between the main part and the plate prior to their assembly, and by obtaining much surer leak proofing of the cavity after assembly. Another advantage is that the level of vibrations for which the vane is the seat is reduced.
Under a general form, the invention may be defined as a turbine engine vane comprising a main part containing a cavity and ribs extending into the cavity, and a plate joined to the main part while closing the cavity and while resting on the ribs, characterised in that the plate is joined to the main part while resting on a bearing surface of the main part, set back with respect to an outer face of the main part that surrounds it, by a region adjacent to an outer edge of the plate.
The plate is flush with the outer surface of the main part, and the vane thus has a surface of perfect continuity, or nearly so, without final machining. The bearing of the plate on the ribs reduces its possibilities of vibrating. The interleaving of the plate in the bearing surface set back from the outer surface of the main part makes it possible not to expose the leak proofing means to the outer surface and thus reduces the risks that they are damaged accidentally, or eliminated by a final machining of the vane, which is moreover not indispensable in the invention. Another advantage of the interleaving of the plate in the main part is that it may be placed in the correct position without precaution during assembly.
In a preferred embodiment, the outer edge of the plate extends above a groove of the main part which surrounds the bearing surface and is filled by a seal made of elastic material, the seal being compressed by the outer edge. Leak proofing is guaranteed by the compression of the joint by the outer edge of the plate.
The positioning of the plate and of the main part is advantageously procured by centring pins penetrating into aligned holes; it is then advantageous that the seal extends into these holes once the centring pins have been removed.
The holes may extend at the place of the ribs, near to their connection to the actual main part.
Another aspect of the invention is a method characterised in that it consists, after having laid the plate on the ribs and before fixing the plate onto the main part, in introducing centring pins into the aligned holes.
The invention will now be described with reference to the following figures, which give several embodiments thereof for purely illustrative purposes:
The other elements of the vane 3 are a smooth plate 10 that is assembled to the main part 5 while closing the cavity 8 and an elastomer seal 11, the shape of which corresponds to the contour of the plate 10.
Other details of the invention will now be described by means of
Number | Date | Country | Kind |
---|---|---|---|
11 56594 | Jul 2011 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/FR12/51690 | 7/17/2012 | WO | 00 | 1/17/2014 |