Turbine stator vane comprising an inner cooling wall produced by additive manufacturing

Abstract

A stator vane of a turbine of a gas turbine engine, including an outer platform and an inner platform between which there extends an outer wall forming an outer skin, wherein it includes an inner wall, forming an inner skin, facing the outer wall so as to define an inter-skin cavity between the outer wall and the inner wall, the inner wall including a plurality of cooling orifices for impingement cooling of the outer wall, the outer wall and inner wall being produced by additive manufacturing.

Claims

1. A turbine distributor vane of a gas turbine engine, comprising: an outer platform; an inner platform; an outer wall extending between the outer platform and the inner platform, the outer wall forming an outer skin; an inner wall forming an inner skin, the inner wall facing the outer wall so as to define an inter-skin cavity between the outer and inner walls, the inner wall including a plurality of cooling orifices for cooling the outer wall by impact; and a hook provided at the outer platform, wherein the vane is a single monolithic piece produced by additive manufacturing, wherein an upstream end of the hook is downstream of an upstream end of the inner platform, and wherein the inner skin is integrated under the hook such that the upstream end of the hook is radially superimposed on a portion of the inner skin.

2. The vane according to claim 1, wherein a junction between the outer and inner walls is formed at the outer platform.

3. A turbine of a gas turbine engine, comprising a plurality of distributor vanes according to claim 1.

4. A turbomachine, comprising the turbine according to claim 3.

5. A method for manufacturing the distributor vane according to claim 1, wherein the vane is produced by laser melting on a bed of metal powder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood upon reading the detailed description which follows, of an example of a non-limiting embodiment thereof, as well as upon examining the schematic and partial figures of the appended drawing, on which:

(2) FIG. 1 very schematically illustrates, in section, an example of cooling a distributor vane by a multi-drilled insert with impact cooling orifices,

(3) FIG. 2 illustrates the appearance of leaks generated by the presence of an insert added onto the vane of FIG. 1,

(4) FIG. 3 illustrates the impact distance between the distributor vane and the insert on the vane of FIG. 1,

(5) FIG. 4 partially shows, in a perspective and sectional view, an example of a distributor vane according to the invention,

(6) FIG. 5 very schematically illustrates, in section, the operation of the vane of FIG. 4, and

(7) FIGS. 6A to 6C schematically illustrate, in partial section, the cases of distributor vanes according to the prior art (FIG. 6A), according to the invention (FIG. 6B), and the comparison between the two in terms of space requirement (FIG. 6C).

(8) In all of these figures, identical references can designate identical or similar elements.

(9) In addition, the different portions shown in the figures are not necessarily on a uniform scale, to make the figures more readable.

DETAILED DESCRIPTION OF A PARTICULAR EMBODIMENT

(10) FIGS. 1 to 3 have been described above in the part relating to the prior art and to the technical background of the invention.

(11) FIG. 4 partially shows, in a perspective view and in section, an example of a distributor vane 1 in accordance with the invention, and FIG. 5 very schematically illustrates, in section, the operation of the vane of FIG. 4.

(12) In order to be able to overcome the disadvantages of the solutions of the prior art presented above, based essentially on the use of an insert, the invention advantageously uses the additive manufacturing method, for example laser melting on a bed of metal powder, in order to integrate a cooling skin with the vane 1. Thus, the distributor vane 1 becomes an integrated double-skin vane ensuring cooling by air jet impacts.

(13) Thus, with reference to FIG. 4, the distributor vane 1 includes an outer platform 5 and an inner platform 6, visible in FIG. 6B, between which extends an outer wall 7, which forms an outer skin.

(14) Advantageously, the vane 1 is provided with an inner wall 8, which forms an inner cooling skin integrated by additive manufacturing. In this way, there is a continuity of material between the inner skin and the distributor rim without having to resort to welding.

(15) This inner skin 8 allows to cool the outer skin 7 which is in contact with the hot gases of the aerodynamic flow path. For this purpose, the inner skin 8 includes cooling orifices 3 which project the cooling air by impact on the outer skin 7.

(16) These cooling orifices 3 are obtained directly by additive manufacturing. They allow the air jets to be oriented towards the areas to be cooled.

(17) The outer 7 and inner 8 skins define therebetween an inter-skin cavity 10 wherein the cooling air from the cooling orifices 3 circulates before cooling the outer skin 7 by impact.

(18) Advantageously, the entire vane is obtained by additive manufacturing. The junction J between the outer 7 and inner 8 skins is located radially near the outer platform 5.

(19) Note also that in FIG. 4, the reference 9 designates a front hook of the distributor which allows the part to be connected to the turbine ring.

(20) The advantages of the proposed solution mainly result from the integration of a cooling skin with the vane by additive manufacturing. Thus, the connection between the inner skin and the rim of the distributor is impermeable, which makes the proposed cooling device tight.

(21) In addition, it is not necessary to provide arrangements which make possible or facilitate the mounting of the inner cooling skin. It is thus possible to design very compact distributors. By way of examples, FIGS. 6A to 6C schematically illustrate, in partial section, the cases of distributor vanes according to the prior art (FIG. 6A), according to the invention (FIG. 6B), and the comparison between the two in terms of space requirement (FIG. 6C).

(22) FIG. 6A shows the conventional embodiment of a vane 1′ with the presence of an insert 2. In FIG. 6B, the vane 1 includes the double skin 7, 8 in accordance with the invention. In FIG. 6C which compares the vanes 1′ according to the prior art and 1 according to the invention, it is seen that the inner skin 8 is integrated under the front hook 9 of the distributor. In particular, the end of the front hook 9 is radially superimposed on the inner skin 8. This allows to reduce the axial space requirement with a gain in size G, and thus to reduce the mass of the engine, increasing its efficiency.

(23) In addition, the solution proposed by the invention is economical because the expensive operations of welding and drilling an insert are removed.

(24) Moreover, it is possible to have a high degree of control over the distance between the inner cooling skin 8 and the outer skin 7 of the vane 1, in other words over the axial dimension of the inter-skin cavity 10. The cooling efficiency is therefore optimal.

(25) Of course, the invention is not limited to the exemplary embodiment which has just been described. Various modifications can be made thereto by a person skilled in the art.