NOZZLE, AIR-ASSISTED SPRAY DEVICE, ASSOCIATED COATING AND REPAIR PROCEDURES

Description

DOMAINE TECHNIQUE DE L'INVENTION

[0001] The technical field of the invention is that of the repair of aircraft turbomachine parts.

[0002] The present invention relates to a nozzle, a dynamic gas projection device for powdered material, a dynamic projection coating method and a method for repairing an annular contact flange of aircraft turbomachinery associated. ARRIERE-PLAN TECHNOLOGIQUE DE L'INVENTION

[0003] Frequently, during the repair of aircraft turbomachinery components, accessibility issues arise. These issues exist, for example, in cases of damage caused by friction wear of the annular contact flange between the engine and the gearbox of a turbomachine (known as the "J-ring"), for which no industrially applicable structural repair solution is known. In cases of excessive wear, this annular contact flange is replaced entirely. Such an annular contact flange 11 is shown in the figure 1 .

[0004] Replacing an aluminum J-ring is a complex and time-consuming operation. Therefore, it would be beneficial to find an alternative to replacing this part that allows for repair under the wing, i.e., while the part is still installed on the turbomachine, and also allows for the aircraft to be released quickly.

[0005] A dynamic projection repair method (in English "cold spray"), called resurfacing, can be implemented with a nozzle that projects a direct jet of very high-speed metallic powder to fill damage to the surface of worn parts.

[0006] There figure 2 This schematically represents a conventional projection device 50 equipped with a nozzle 10. This device 50 includes, among other things, a nozzle 10 and a projection torch 60 located in the longitudinal extension of the nozzle 10. The conventional device 50 is placed opposite a surface to be reloaded S, in other words, to be coated with an initially powdery material. figure 3 is a cross-sectional view of the geometry of a J-ring type annular contact flange 11 and a repairable Z-zone of this annular contact flange 11. It can be observed, as illustrated in the figures 4 et 5 , that a projection device as illustrated on the figure 2 cannot be inserted into this architecture without interfering with other components adjacent to the annular contact flange 11. In other words, the geometry of the "J-Ring" type annular contact flange 11 makes it impossible to use a conventional projection device 50 as illustrated in the figure 2 .

[0007] Document JP S51 47936 describes a device for spraying a powder. RESUME DE L'INVENTION

[0008] The invention offers a solution to the problems mentioned above, making it possible to overcome the aforementioned accessibility and space constraints in order to repair under the wing a "J-Ring" type turbomachine part, or any other type of part whose geometry does not allow the use of a conventional repair device.

[0009] A first aspect of the invention relates to a nozzle comprising: a gas supply duct for the projection gas, a chamber for mixing the projection gas and powder material into an accelerated mixture connected, at an upstream end, to the gas supply duct for the projection gas, a projection duct for the accelerated mixture connected to a downstream end of the mixing chamber, the gas supply duct for the projection gas being U-shaped with a first branch oriented along a first axis and a second branch oriented along a second axis perpendicular to the first axis, the first branch being connected to the upstream end, the projection duct for the accelerated mixture extending straight along the first axis and including a projection opening.

[0010] Thanks to the invention, it is possible to position the nozzle according to the invention so that, after integration into a gas projection device, the projection direction and the gas injection direction are different.

[0011] A second aspect of the invention relates to a dynamic gas-jet projection device for powdered material comprising a nozzle as previously described and: a projection torch extending along the second axis and connected to the second branch of the projection gas supply duct, a powder material supply duct connected to the mixing chamber.

[0012] Thus, the dynamic gas projection device according to the invention is more compact and can be inserted into confined spaces such as the area around a J-ring type annular contact flange. Repairing such components "under" the wing, i.e., while still installed on a turbomachine, is therefore possible, eliminating the need for complete component replacement. This under-wing repair offers a time saving compared to a full replacement.

[0013] Advantageously, the powder material feed conduit extends along a third axis perpendicular to the first and second axes.

[0014] A third aspect of the invention relates to a coating process by dynamic projection of powder (metallic or partially metallic) onto a metal part implemented by a dynamic projection device as described above, comprising the following steps: positioning of a surface to be coated opposite the projection opening, injection of high-speed gas into the projection torch, injection of a powder into the powder material feed duct, projection of the mixture formed by the high-speed gas and the powder via the projection duct onto the surface to be coated.

[0015] In this discussion, the powder may be metallic or partially metallic.

[0016] Advantageously, high-speed gas is a cold gas.

[0017] In this presentation, the term "cold gas" refers to a high-speed gas with a temperature below 750°C.

[0018] Advantageously, the powder is composed mainly of aluminum or aluminum alloy. This is particularly suitable for a part made of aluminum or aluminum alloy.

[0019] A fourth aspect of the invention relates to a method for repairing an annular contact flange of an aircraft turbomachine implemented by a dynamic projection device as described above, comprising the following steps: positioning of a part of the annular contact flange to be repaired opposite the projection opening, injection of high-speed gas into the projection torch, injection of a metal powder into the powder material feed duct, projection of the mixture formed by the high-speed gas and the metal powder via the projection duct onto said part, the annular contact flange being installed on a turbomachine.

[0020] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BREVE DESCRIPTION DES FIGURES

[0021] The figures are presented for illustrative purposes only and are in no way limiting to the invention. There figure 1 This shows a J-ring type annular contact flange installed on an aircraft turbomachine inverter. figure 2 It demonstrates a dynamic projection device based on prior art. figure 3 is a profile view of an annular contact flange such as that of the figure 1 . There figure 4 schematically represents a virtual intersection of a prior art dynamic projection device with a J-ring type annular contact flange. figure 5 schematically represents another virtual intersection of a prior art dynamic projection device with a J-ring type annular contact flange. figure 6 represents a nozzle according to an example of an embodiment of the invention. figure 7 represents a perspective view of a dynamic projection device according to an embodiment of the invention, in its functional position. figure 8 represents a profile view of the dynamic projection device of the figure 7 in functional position for repairing a "J-Ring" type annular contact flange. DESCRIPTION DETAILLEE

[0022] The figures are shown for illustrative purposes only and are not intended to limit the invention. Unless otherwise specified, the same element appearing in different figures has a unique reference numeral.

[0023] A first object of the invention relates to a nozzle 1, shown on the figure 6 .

[0024] Nozzle 1 of the figure 6 understand : a projection gas supply conduit 2, a mixing chamber 3 of projection gas and powder material into an accelerated mixture connected, by an upstream end 31, to the projection gas supply conduit 2, a projection conduit 4 of the accelerated mixture connected to a downstream end 32 of the mixing chamber 3.

[0025] The terms upstream and downstream are defined relative to the direction of propagation of the accelerated mixture, from the mixing chamber 3 towards a surface to be recharged.

[0026] The projection gas supply conduit 2 is U-shaped with a first branch 21 oriented along a first axis X and a second branch 22 oriented along a second axis Y perpendicular to the first axis X. The first branch 21 is connected to the upstream end 31.

[0027] The accelerated mixture projection conduit 4 extends straight along the first X axis and includes a projection opening 41 through which the accelerated mixture from the mixing chamber 3 is projected. This supply after the bends prevents clogging of the nozzle 2.

[0028] A second object of the invention relates to a dynamic gas projection device 5 for powdered material comprising a nozzle 1 such as the nozzle 1 shown in the figure 6 An example of this dynamic projection device 5 is shown on the figure 7 .

[0029] The dynamic projection system 5 also includes: a projection torch 6 extending along the second Y axis and connected to the second branch 22 of the projection gas supply conduit 2, a powder material supply conduit 7 connected to the mixing chamber 3.

[0030] On the figure 7 A surface to be recharged 8 is also shown, in other words to be coated with metallic powder by the dynamic projection device 5. Furthermore, geometric elements 9 are also shown on the figure 7 These geometric elements 9 do not allow the use of a conventional projection device 50 such as the one shown on the figure 2 Indeed, these would interfere with the projection torch 60, which could not be positioned in line with the nozzle 10, as already illustrated in the figures 4 et 5 .

[0031] As seen on the figure 7 The positioning of the projection torch 6 along the second Y axis, here vertical, allows the dynamic projection device 5 to be inserted into the available space between the surface to be recharged 8 and the geometry elements 9. Thus, the projection of metallic powder onto the surface to be repaired 8 is made possible.

[0032] Advantageously, the powder material feed duct 7 is connected to the mixing chamber 3, that is, downstream of the projection gas feed duct 2. This position of the junction between the powder material feed duct 7 and the nozzle 1 prevents damage to the latter. Indeed, tests have shown that feeding powder upstream of the "U" shape of the projection gas feed duct 2 causes perforation or clogging of the nozzle 1, rendering it unusable in this configuration.

[0033] There figure 8 is a side view of the dynamic projection device 5 of the figure 7 in the functional projection position on a J-Ring type annular contact flange 11. It can be observed on the figure 8 that the geometry of the dynamic projection device 5 allows its insertion so as to position the projection conduit 4 substantially perpendicular to the inner surface of the annular contact flange of type "J-Ring" 11.

[0034] We now describe a method for repairing under the wing of a "J-Ring" type annular contact flange 11 with worn parts.

[0035] The annular contact flange 11 is installed on an aircraft turbomachine.

[0036] The dynamic projection device 5 described above, as illustrated on the figure 7 , is installed so that the projection duct 4 is approximately perpendicular to a surface to be recharged, with the projection opening opposite the surface to be recharged.

[0037] Preferably, the projection principle is a dynamic projection by cold gas (“cold spray”).

[0038] Gas is supplied to the dynamic projection device 5 via the projection torch 6 and then the projection gas supply line 2. The gas is, for example, nitrogen or helium. The gas is a very high-velocity gas. A powdered material is supplied to the dynamic projection device 5 via the powder material supply line 7. For example, the powdered material is aluminum powder.

[0039] The gas and powdered material mix in mixing chamber 3 to form an accelerated mixture.

[0040] The accelerated mixture is then propelled at supersonic speed and ejected from the dynamic projection device 5 through the projection opening 41 towards the surface to be coated. Once propelled from the nozzle 1, the solid particles forming the accelerated mixture, after a certain projection distance, collide with the surface to be coated. The particles stack up and form a coating on the surface.

[0041] The projection device 5 can then be moved to renew the reloading process in order to reload another surface of the annular contact flange.

[0042] The repair procedure previously described for an annular contact flange can be adapted to any other component whose shape and arrangement in a turbomachine do not allow the use of a conventional projection device, such as that of the figure 1 .

Claims

1. A device for gas dynamically spraying (5) powdered material comprising - a nozzle (1) comprising: ∘ a spray gas supply duct (2), ∘ a chamber (3) for mixing spray gas and powdered material to form an accelerated mixture, connected, through an upstream end (31), to the spray gas supply duct (2), ∘ a spray duct (4) for the accelerated mixture connected to a downstream end (32) of the mixing chamber (3), the spray gas supply duct (2) being "U" shaped with a first arm (21) oriented along a first axis (X) and a second arm (22) oriented along a second axis (Y) perpendicular to the first axis (X), the first arm (21) being connected to the upstream end (31), the spray duct (4) for the accelerated mixture rectilinearly extending along the first axis (X) and comprising a spray opening (41), said device comprising: - a spray torch (6) extending along the second axis (Y) and connected to the second arm (22) of the spray gas supply duct (2), and - a powdered material supply duct (7) connected to the mixing chamber (3), said device being characterised in that the powdered material supply duct (7) extends along a third axis perpendicular to the first axis (X) and to the second axis (Y).

2. A method for coating a metal piece by dynamically spraying powder, implemented by a device (5) for dynamically spraying powder according to the preceding claim, comprising the following steps of: - positioning a surface to be coated facing the spray opening (41), - injecting high-speed gas into the spray torch (6), - injecting a powder into the powdered material supply duct (7), - spraying the mixture formed by the high-speed gas and the powder via the spray duct (4) onto the surface to be coated.

3. The coating method according to claim 2, characterised in that the high-speed gas is a cold gas.

4. The coating method according to one of claims 2 or 3, characterised in that the powder is mostly comprised of aluminium or aluminium alloy.

5. A method for repairing an annular contact flange (11) for an aircraft turbomachine implemented by a dynamic spray device (5) according to claim 1, comprising the following steps of: - positioning a part of the annular contact flange (11) to be repaired facing the spray opening (41), - injecting high-speed gas into the spray torch (6), - injecting a metallic powder into the powdered material supply duct, - spraying the mixture formed by the high-speed gas and the metallic powder via the spray duct (4) onto said part, characterised in that the annular contact flange (11) is installed on a turbomachine.