Sealed instrumentation passage device and method of producing the same
A passage device with a metal tube and inclined orifice addresses leaks and bulk issues, ensuring a sealed and robust connection for electrical signals in turbomachines, maintaining wall integrity and reducing handling complexity.
Patent Information
- Application Number
- FR2023012470
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-11-14
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2043-11-14
AI Technical Summary
Existing sealed passage devices for passing electrical signals through a wall in turbomachines suffer from leaks due to pressure and temperature differences, have a significant bulk, and are not robust, making them unsuitable for precise applications where the wall surface is critical.
A passage device with a metal tube inserted through an inclined orifice in the wall, where the electrical wire is housed and fixed to the wall, using techniques like laser microwelding and brazing to ensure a sealed and robust connection, minimizing deformation and footprint.
The solution provides a reliable, leak-proof, and space-efficient passage that maintains the integrity of the wall surface, even under varying pressure and temperature conditions, while being robust and easy to handle.
Smart Images
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Abstract
Description
Title of the invention: Sealed instrumentation passage device and method for producing the same TECHNICAL FIELD OF THE INVENTION
[0001] The technical field of the invention is that of sealed passage devices for passing an electrical signal through a wall.
[0002] The present invention relates to a sealed passage device preferably provided for passing an instrumentation control wire through a wall in a turbomachine. The present invention also relates to a method for producing such a sealed passage device. TECHNOLOGICAL BACKGROUND OF THE INVENTION
[0003] In the field of turbojets, it is known to use bolted sealed passage devices to pass an electrical signal through a wall. An example of a sealed passage device 1 usually used is illustrated in [Fig.l], where a first electrical wire 2, for example an incoming wire, and a second electrical wire 3, for example an outgoing wire, each located on a different side of a wall 4, are connected to a screw 5 and each gripped between two washers 6, said screw 5 being introduced through an opening provided in the wall 4. A sealing assembly 7 comprising two insulating rings 8 enclosing a silicone elastomer 9 is provided at said opening. The washers 6 and the sealing assembly 7 are clamped on either side of the wall 4 by a set of nuts 10 and lock nuts 11 screwed onto the free end of the screw 5.
[0004] This passage device 1 is usually sealed, but leaks have however been observed during its use on certain turbojets, in particular when there is a significant difference in pressure and / or temperature between the two sides of the wall 4. Leaks of silicone elastomer 9 have in particular been observed, probably caused by liquefaction of the silicone when it is subjected to very high temperatures and trapped.
[0005] Furthermore, the sealed passage device 1 according to the prior art is not entirely satisfactory because it has a significant bulk on both sides of the wall and the clamping device used is not very robust and can be difficult to access.
[0006] There is therefore a need for a passage device intended to pass an electrical signal through a wall and which remains sealed when there is a significant difference in pressure and / or temperature between the two sides of said wall. Advantageously, such a device must be reliable, robust and have a small footprint on both sides of the wall.
[0007] In the case where a face of the wall crossed is subject to very strict tolerances, in particular when this face serves as a precision surface for another part, the production and use of the passage device must not deform the wall, and in particular must not heat it significantly. Summary of the invention
[0008] The invention offers a solution to the problems mentioned above, by introducing a tube into the wall to be crossed through an inclined opening and by passing an electric wire into this tube before pressing the assembly against the wall, a seal being provided between the tube and the wall and between the tube and the electric wire.
[0009] One aspect of the invention relates to a sealing assembly for a turbomachine formed by a wall having a through opening, a first electrical wire provided on a first side of said wall, a second electrical wire provided on a second side of said wall and a sealed passage device provided to connect the two electrical wires through said through opening, the assembly being characterized in that the through opening is an orifice inclined at an acute angle α relative to the wall, in that the passage device comprises: • a metal tube housed in the inclined orifice, having a first beveled end of which one edge is flush and sealed with an edge of the inclined orifice located on the first side of said wall, and a second end which extends on the second side of said wall; • an electrical connecting wire, housed in the metal tube, having a first end extending outside said tube and electrically connected to the first electrical wire and a second end extending outside the tube and electrically connected to the second electrical wire, the electrical connecting wire being fixed in a sealed manner to the tube; and in that • the metal tube and the connecting electric wire are deformed so as to be pressed against the wall, and they are fixed to the wall.
[0010] Thanks to the invention, a device is provided for passing through a wall which remains sealed, even in the event of a significant difference in pressure and / or temperature between the two sides of said wall. Advantageously, this passage device is reliable, robust and has a small footprint on both sides of the wall. The inclination of the passage orifice contributes to the small footprint of the device and advantageously makes it possible not to have to handle the electrical connection wire too much and only to bend it very slightly, unlike a passage device substantially equivalent to that of the invention and shown in [Fig. 12] where the passage orifice is not inclined.
[0011] The use of a tube in which the electrical connecting wire is housed allows to move the soldering area away from the wire so as not to affect the part fitted with the wall, and also allows the wire to be laid at the last moment, for example just before mounting on an engine, rather than during manufacturing, in order to reduce handling of the electrical connecting wire and avoid deterioration of the electrical signal it transmits.
[0012] In addition to the characteristics which have just been mentioned in the preceding paragraph, the assembly according to one aspect of the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations: • a is between 5 and 45 degrees, preferably between 10 and 30 degrees and more preferably between 15 and 25 degrees. • the edge of the first beveled end of the tube is welded with the edge of the inclined orifice by 360° laser microwelding or 360° TIG microwelding. • the electrical connecting wire is fixed in a watertight manner to the tube by brazing or welding at the second end of said tube, by gluing, or by injecting resin or elastomer between the electrical connecting wire and the tube. • the second end of the metal tube is fixed to the second side of the wall by bridges glued or spot welded to the second side of the wall. • the second end of the electrical connecting wire is fixed to the second side of the wall by bridges glued or spot welded to the second side of the wall. • the first end of the electrical connecting wire is fixed to the first side of the wall by bridges glued or spot welded to the first side of the wall. • the metal tube is made of the same material as the wall or of a material chemically compatible with welding with the wall material.
[0013] Another aspect of the invention relates to a method for forming a sealed passage for a turbomachine intended to connect a first electrical wire provided on a first side of a wall and a second electrical wire provided on a second side of said wall through said wall by means of a sealed passage device, characterized in that it comprises the following successive steps: • providing a through opening in the wall by drilling an orifice inclined at an acute angle a relative to said wall; • introduction of a metal tube into the through opening, a first end of which is beveled before or after introduction into the through opening and a second end of which extends on the second side of said wall; • positioning the metal tube so that one edge of its first beveled end is flush with an edge of the inclined orifice located on the first side of the wall; • micro-welding in a watertight manner of the edge of the first beveled end with the edge of the inclined orifice located on the first side of the wall; • introduction of an electrical connecting wire inside the tube, said electrical connecting wire having a first end extending outside said tube and capable of being electrically connected to the first electrical wire, and a second end extending outside the tube and capable of being electrically connected to the second electrical wire; • watertight fixing of the electrical connection wire to the tube; • deformation of the metal tube and the connecting electric wire, and pressing them against the wall; and • fixing the metal tube and the electrical connecting wire to the wall.
[0014] Thanks to the invention, a leaktight, reliable, robust and space-saving passage device is provided on both sides of the wall. Advantageously, the techniques used to carry out each step of the method do not heat the wall significantly and are not likely to deform it.
[0015] In addition to the characteristics which have just been mentioned in the preceding paragraph, the method according to another aspect of the invention may have one or more additional characteristics among the following, considered individually or according to all technically possible combinations: • the drilling of the inclined orifice is carried out by electroerosion. • drilling the inclined hole is followed by a step of reconditioning the wall at the level of said orifice. • the watertight welding of the edge of the first end of the tube on the edge of the inclined orifice is carried out without adding material. • the watertight welding of the edge of the first end of the tube on the edge of the inclined orifice is carried out at 360° by laser microwelding or by TIG microwelding. • the watertight fixing of the electrical connection wire to the tube is carried out by brazing or welding at the second end of said tube, by gluing, or by injecting resin or elastomer between the electrical connection wire and the tube. • when fixing the metal tube and the connecting electric wire to the wall, the second end of the metal tube is fixed to the second side of the wall by bridges glued or spot welded to the second side of the wall. • when fixing the metal tube and the connecting electric wire to the wall, the second end of the connecting electric wire is fixed to the second side of the wall by bridges glued or spot welded to the second side of the wall. • when fixing the metal tube and the connecting electric wire to the wall, the first end of the connecting electric wire is fixed to the first side of the wall by bridges glued or spot welded to the first side of the wall.
[0016] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES
[0017] The figures are presented for information purposes only and in no way limit the invention. In the figures, the electrical wires are shown in black and certain distances or dimensions have been exaggerated for reasons of clarity of the figures.
[0018] [Fig.l] is a schematic sectional view of a passage device according to the prior art.
[0019] [Fig.2], [Fig.3] and [Fig.4] are schematic sectional views of a wall having an inclined orifice according to the invention, illustrating the introduction of a metal tube according to the invention.
[0020] [Fig.5] is a schematic detail view of the circled part [Fig.4] and illustrating the microwelding of the edge of the tube with the edge of the inclined orifice.
[0021] [Fig.6] is a view equivalent to [Fig.3] illustrating the introduction of an electric connecting wire into the metal tube according to the invention.
[0022] [Fig.7] is a schematic detail view of the circled part [Fig.6] and illustrating the fixing of the electrical connecting wire to the tube by brazing.
[0023] [Fig.8] is a view equivalent to [Fig.6] illustrating the deformation of the metal tube and the connecting electric wire, as well as their plating and fixing against the wall.
[0024] [Fig.9] is a view equivalent to [Fig.8] illustrating the connection of the connecting electrical wire to the first and second electrical wires.
[0025] [Fig. 10] is a schematic plan view of an example of a passage device according to the invention seen from a first side of the wall.
[0026] [Fig. 11] is a schematic plan view of the example passage device of [Fig. 10], but seen from a second side of the wall.
[0027] [Fig. 12] is a schematic sectional view of a passage device illustrating the case where the wall does not have an inclined orifice according to the invention. DETAILED DESCRIPTION
[0028] Unless otherwise specified, the same element appearing in different figures presents a unique reference.
[0029] The invention relates to a sealed passage device 20 provided to ensure electrical continuity between a first electrical wire 2 provided on a first side 41 of a wall 4 and a second electrical wire 3 provided on the second side 42 of said wall 4, opposite the first.
[0030] Said wall 4 has a through opening which is characterized by the fact that it comprises an inclined orifice 50, the axis A-A' of which along which it extends forms an acute angle a relative to the axis Z-Z' along which the wall 4 extends. According to a preferred embodiment, this acute angle a is between 5 and 45 degrees, preferably between 10 and 30 degrees and more preferably between 15 and 25 degrees (see [Fig.2]).
[0031] The passage device 20 comprises a metal tube 60 housed in the inclined orifice 50. This metal tube 60 has a first end 61 located on the first side 41 of the wall 4 and a second end 62 located on the first side 41 of the wall 4 (see [Fig.3]).
[0032] The first end 61 is beveled and positioned so that its edge 615, i.e. its radial end surface, is flush with the edge 55 of the inclined orifice 50 located on the first side 41 of the wall 4 and which forms the contour of the entrance to the inclined orifice 50 (see [Fig.4]). The first end 61 may be beveled before or after the introduction of the metal tube 60 into the inclined orifice 50. • The edge 615 is welded in a sealed manner with the edge 55 of the inclined orifice 50 with which it is flush (see [Fig. 5]). This welding is preferably obtained by 360° laser microwelding or by 360° TIG microwelding, preferably without adding material. Laser microwelding and TIG microwelding are preferred in that they allow the first end 61 of the tube 60 to be fixed to the inclined orifice 50 in a sealed manner from the first side 41 of the wall 4 without significantly heating said wall 4 so that it does not deform. In order to facilitate this welding, the tube 60 is preferably manufactured from the same material as that of the wall 4 or from a material chemically compatible with welding with the material of the wall 4.
[0033] The metal tube 60 extends by a distance D from the second side 42 of the wall 4.
[0034] The passage device 20 also comprises an electrical connecting wire 70 housed in the metal tube 60 (see [Fig.6]). This electrical connecting wire 70 has a first end 71 located on the first side 41 of the wall 4, which extends outside said tube 60 at its first end 61 and which is intended to be electrically connected to the first electrical wire 2. The electrical connecting wire 70 also has a second end 72 located on the second side 42 of the wall 4, which extends out of the tube 60 at its second end 62 and which is intended to be electrically connected to the second electrical wire 3.
[0035] The electrical connecting wire 70 is fixed in a sealed manner to the tube 60, for example by brazing or by welding its second end 72 with the second end 62 of the tube 60 (see brazing 110 in [Fig.7]). When the wall is not subject to high temperatures, this fixing can also be done by gluing, or by injecting resin or elastomer between the electrical connecting wire 70 and the tube 60.
[0036] The distance D is sufficiently long so that the heat transmitted to the tube 60 and to the connecting electric wire 70 during brazing or welding is not transmitted to the wall 4 in a significant manner so as to deform it.
[0037] The metal tube 60 and the electrical connecting wire 70, for example initially substantially rectilinear, in particular when the electrical connecting wire 70 is introduced into the tube 60 (see [Fig. 6]), are folded down and pressed against the wall 4, for example by bending them. They are also fixed to the wall 4 (see [Fig. 8]).
[0038] According to a preferred embodiment of the invention, the second end 62 of the tube 60 is fixed to a face of the wall 4 located on the second side 42 by bridges 80 glued or spot welded to said wall 4, the first end 71 of the electrical connecting wire 70 is fixed to a face of the wall 4 located on the first side 41 by bridges 80 glued or spot welded to the first side 41 of the wall 4, and / or the second end 62 of the metal tube 60 is fixed to a face of the wall 4 located on the second side 42 by bridges 80 glued or spot welded to said wall 4.
[0039] The wire ends 71, 72 of the electrical connecting wire 70 can be connected in a conventional manner to the free end of the first electrical wire 2 and the second electrical wire 3. According to a preferred embodiment shown in [Fig.9], these connections are made by a welding point 90, protected from the outside by a deformable metal plate 100 glued or spot welded to the wall 4.
[0040] The invention also relates to a method for producing the sealed passage device 20 according to the invention.
[0041] This method preferably comprises the following successive steps: • providing a through opening in the wall 4 by drilling an inclined orifice 50 at an acute angle α relative to said wall 4; • introduction of a metal tube 60 through the inclined orifice 50, a first end 61 of the tube 60 being beveled before or after introduction through the inclined orifice 50, and a second end 62 of the tube 60 extending from the second side 42 of said wall 4; • positioning of the tube 60 so that an edge 615 of its first beveled end 61 is flush with an edge 55 of the inclined orifice 50 located on the first side 41 of the wall 4; • micro-welding in a watertight manner of the edge 615 of the first beveled end 61 with the edge 55 of the inclined orifice 50 located on the first side 41 of the wall 4, preferably without adding material; • introduction of an electrical connecting wire 70 inside the tube 60, a first end 71 of said connecting wire 70 extending outside the tube 60 to be electrically connected to the first electrical wire 2, and a second end 72 of the connecting wire 70 extending outside the tube 60 and to be electrically connected to the second electrical wire 3; • watertight fixing of the electrical connecting wire 70 to the tube 60; • deformation of the metal tube 60 and the electrical connecting wire 70, and pressing them against the wall 4; and • fixing the metal tube 60 and the electrical connecting wire 70 on the wall 4.
[0042] The drilling of the inclined orifice 50 is preferably carried out by electroerosion. It is preferably followed by a step of reconditioning the wall 4 at the level of said inclined orifice 50, for example by adjustment or machining, to remove the thin layer of material thermally affected by the electroerosion.
[0043] The sealed welding of the edge 615 of the first end 61 of the tube 60 on the edge 55 of the inclined orifice 50 is preferably carried out at 360° by laser microwelding or by TIG microwelding.
[0044] The sealing attachment of the electrical connecting wire 70 to the tube 60 is preferably carried out by brazing or welding at the second end 62 of said tube 60, or by gluing or injection of resin or elastomer between the electrical connecting wire 70 and the tube 60.
[0045] The second end 62 of the metal tube 60 is preferably fixed to the second side 42 of the wall 4 by bridges 80 glued or spot welded to the second side 42 of the wall 4.
[0046] Similarly, the second end 62 of the electrical connecting wire 70 is preferably fixed to the second side 42 of the wall 4 by bridges 80 glued or spot welded to the second side 42 of the wall 4.
[0047] Similarly, the first end 71 of the electrical connecting wire 70 is preferably fixed to the first side 41 of the wall 4 by bridges 80 glued or spot welded to the first side 41 of the wall 4.
[0048] A sealed passage 20 according to the invention was produced through the wall 4 of a turbojet shell made of inconel approximately 5 cm thick, with a tube 60 made of inconel 50 cm long, having an outside diameter of approximately 4 cm and an inside diameter of approximately 2.5 cm, electrical wires 2, 3, 70 approximately 2.5 cm thick, an inclined orifice 50 produced by electroerosion with an angle a of approximately 20°, laser microwelding of the tube 60 on the inclined orifice 50 without adding material, and an electrical connecting wire 70 brazed with a torch at the second end 62 of the tube 60. The passage 20 obtained was subjected to high temperatures and pressures, higher than those which can usually be encountered during the normal operation of a turbojet, and showed great mechanical robustness and excellent maintenance of the seal.
[0049] It will be noted that the electrical wires 2, 3, 70 of the invention are preferably provided for passing an instrumentation control signal, but the invention can be used for any type of electrical wire. A person skilled in the art can also easily adapt the invention to any other type of wire, in particular optical fibers, cables, flexible rods, capillaries or thin hollow conduits, except that the type of sealing must be adapted to the material of the wire chosen.
[0050] Although described through a certain number of examples, variants and embodiments, the assembly according to the invention, and the method of forming a sealed passage, include various variants, modifications and improvements which will be obvious to those skilled in the art, it being understood that these variants, modifications and improvements are part of the scope of the invention.
Claims
Claims
1. Sealing assembly for a turbomachine, formed of a wall (4) having a through opening, a first electrical wire (2) provided on a first side (41) of said wall (4), a second electrical wire (3) provided on a second side (42) of said wall (4) and a sealed passage device (20) provided to connect the two electrical wires through said through opening, the assembly being characterized in that the through opening is an inclined orifice (50) at an acute angle (a) relative to the wall (4), in that the passage device (20) comprises: - a metal tube (60) housed in the inclined orifice (50), having a first beveled end (61) of which one edge (615) is flush and is welded in a sealed manner with an edge (55) of the inclined orifice (50) located on the first side (41) of said wall (4), and a second end (62) which extends from the second side (42) of said wall (4);- an electrical connecting wire (70), housed in the metal tube (60), having a first end (71) extending outside said tube (60) and electrically connected to the first electrical wire (2) and a second end (72) extending outside the tube (60) and electrically connected to the second electrical wire (3), the electrical connecting wire (70) being fixed in a sealed manner to the tube (60); and in that - the metal tube (60) and the electrical connecting wire (70) are deformed so as to be pressed against the wall (4), and they are fixed to the wall (4).;
2. Assembly according to claim 1, characterized in that (a) is between 5 and 45 degrees, preferably between 10 and 30 degrees and more preferably between 15 and 25 degrees.
3. Assembly according to claim 1 or 2, characterized in that the edge (615) of the first beveled end (61) of the tube (60) is welded with the edge (55) of the inclined orifice (50) by 360° laser microwelding or 360° TIG microwelding.
4. Assembly according to any one of the preceding claims, characterized in that the electrical connecting wire (70) is fixed in such a way sealed to the tube (60) by brazing or welding at the second end (62) of said tube (60), or by gluing or injecting resin or elastomer between the electrical connecting wire (70) and the tube (60).
5. Method for forming a sealed passage for a turbomachine, intended to connect a first electrical wire (2) provided on a first side (41) of a wall (4) and a second electrical wire (3) provided on a second side (42) of said wall (4) through said wall (4) by means of a sealed passage device (20), characterized in that it comprises the following successive steps: - providing a through opening in the wall (4) by drilling an inclined orifice (50) at an acute angle (a) relative to said wall (4); - introduction of a metal tube (60) into the through opening, a first end (61) of which is beveled before or after introduction into the through opening and a second end (62) of which extends on the second side (42) of said wall (4); - positioning the metal tube (60) so that an edge (615) of its first beveled end (61) is flush with an edge (55) of the inclined orifice (50) located on the first side (41) of the wall (4); - sealingly welding the edge (615) of the first beveled end (61) with the edge (55) of the inclined orifice (50) located on the first side (41) of the wall (4); - introduction of an electrical connecting wire (70) inside the tube (60), said electrical connecting wire (70) having a first end (71) extending outside said tube (60) and capable of being electrically connected to the first electrical wire (2), and a second end (72) extending outside the tube (60) and capable of being electrically connected to the second electrical wire (3); - watertight fixing of the electrical connecting wire (70) to the tube (60); - deformation of the metal tube (60) and the electrical connecting wire (70), and pressing them against the wall (4); and - fixing the metal tube (60) and the electrical connecting wire (70) on the wall (4).
6. Method according to claim 5, characterized in that the drilling of the inclined orifice (50) is carried out by electroerosion.
7. Method according to claim 5 or 6, characterized in that the drilling of the inclined orifice (50) is followed by a step of reconditioning the wall (4) at the level of said inclined orifice (50).
8. Method according to any one of claims 5 to 7, characterized in that the sealed welding of the edge (615) of the first end (61) of the tube (60) on the edge (55) of the inclined orifice (50) is carried out without adding material.
9. Method according to any one of claims 5 to 8, characterized in that the sealed welding of the edge (615) of the first end (61) of the tube (60) on the edge (55) of the inclined orifice (50) is carried out at 360° by laser microwelding or by TIG microwelding.
10. Method according to any one of claims 5 to 9, characterized in that the sealing fixing of the electrical connecting wire (70) to the tube (60) is carried out by brazing or welding at the second end (62) of said tube (60), or by gluing or injection of resin or elastomer between the electrical connecting wire (70) and the tube (60).