INLET CONE FOR AN AIRCRAFT TURBOMACHINE

Abstract

The present invention relates to an inlet cone (20) for an aircraft turbomachine (1), this inlet cone (20) being configured to be rotated about an axis (X) and comprising a body (22) of truncated cone shape and a tip (21) made of elastically deformable material fixed to an end (221) of smaller diameter of said body (22), the body (22) comprising through-housings (222) distributed around the axis (X) and parts (23) made of elastically deformable material located in said through-housings (222), in which each of the parts (23) made of elastically deformable material comprises at least one peripheral rim (230) for retaining said part (23) in the corresponding through-housing (222), said at least one peripheral rim (230) bearing on an internal surface (22a) of said body (22). Figure for abstract: Figure 4

Description

Title of the invention: INLET CONE FOR AN AIRCRAFT TURBOMACHINE Technical field of the invention

[0001] The field of the present invention is that of turbomachines, for example aircraft turbomachines. More particularly, the present invention relates to an air inlet cone for such aircraft turbomachines. Technical background

[0002] The state of the art includes in particular documents WO-A1-2020 / 24988), FR-A1-3097200 and WO-A1-2022200733.

[0003] Known from the state of the art are turbomachines extending along a longitudinal axis and comprising, from upstream to downstream, in the direction of gas flow, a fan, one or more compressor stages (for example a low-pressure compressor and a high-pressure compressor), a combustion chamber, one or more turbine stages (for example, a high-pressure turbine and a low-pressure turbine), and a gas exhaust nozzle.

[0004] Conventionally, such turbomachines further comprise, upstream, an air inlet cone which is mounted on the fan, for example by means of a generally annular shroud itself connected to a low-pressure compressor shaft of the turbomachine. The connection between the inlet cone and the shroud is generally achieved by means of bolted assemblies. The downstream end of the shroud is flush with the platforms of the fan blades, being located in the aerodynamic continuity thereof.

[0005] Such an inlet cone comprises an upstream end in the form of a cone tip centered on an axis of rotation of the inlet cone, also corresponding to the longitudinal axis of the fan and of the entire turbomachine.

[0006] This tip is known to be a point on the turbomachine that promotes ice accretion, since its centering on the axis of rotation does not allow significant centrifugal forces to be applied. As a result, in the absence of specific measures, the ice forming on the tip can reach a large size before detaching, with the risk, when it finally detaches from the tip, of damaging the fan blades that it strikes or the engine of the aircraft that ingests it. The mass of ice can also accumulate unevenly on the tip and thus cause undesirable vibrations of the turbomachine.

[0007] In order to overcome this problem, it has been proposed to implement a de-icing system whose aim is to ensure that the ice accreted on the tip is ejected before to reach a critical size. However, this type of system is expensive in terms of mass and size, and above all particularly difficult to set up due to the rotating nature of the inlet cone with which it is equipped.

[0008] It has also been proposed to remove the tip of the inlet cone to deal with these problems of ice accretion during operation. However, the absence of the tip does not allow a portion of the air flow entering the turbomachine during operation to be correctly diverted and guided, in particular to ensure its cooling and improve the air flow. Furthermore, a truncated inlet cone (i.e. without the tip) does not allow the inlet cone to be completely protected against the formation of ice and the ingestion of ice (or other solid particles) by the turbomachine during operation.

[0009] Finally, it is known in the prior art to produce, as illustrated in [Fig.l], an inlet cone 10 with an upstream tip 11 made of flexible material (or otherwise said of elastically deformable material) and a downstream body 12 made of rigid material. The tip 11 is generally bonded to the downstream body 12. In operation, the layer of ice accreted, in particular at the connection between the tip and the body, is weakened to promote the detachment of the ice. However, this way of detaching the layer of ice, by weakening and allowing the cracks to propagate along this layer, may be slower than expected in the case of in-flight operation of the turbomachine. Indeed, the larger the size of the layer of ice, the slower and more difficult the formation of cracks on this layer.Furthermore, the generation of cracks directly between the part of the cone made of soft material and the accreted ice, especially at low temperatures (i.e. between -30°C and 15°C) may not be sufficient since the adhesion of the ice to the cone is stronger than the centrifugal detachment force of the ice. Such a solution is therefore not sufficient to quickly detach the layer of ice forming on the inlet cone into several small pieces without damaging the components of the turbomachine downstream of the cone.

[0010] Furthermore, it is also required that the tip made of flexible material does not generally impair the aerodynamic performance or the mechanical strength of the inlet cone (and therefore of the turbomachine). In particular, an offset and / or a space may be generated at the connection interface between the part made of flexible material and the body made of rigid material. This could cause, during operation, distortions (in particular without aerodynamic continuity) between the part made of flexible material and the body made of rigid material, in which ice can be weakened or introduced into the space. This could irreversibly damage the inlet cone. Thus, such a solution for assembling a flexible part and a body made of rigid material is not entirely satisfactory for limiting ice accretions on the inlet cone as much as possible.

[0011] In this context, it is interesting to propose a solution making it possible to overcome the drawbacks of the prior art, in particular by implementing a new geometry of an air inlet cone which further promotes the controlled breaking of the ice during operation. Summary of the invention

[0012] The present invention thus proposes an inlet cone for an aircraft turbomachine, this inlet cone being configured to be driven in rotation around an axis X and comprising a body of truncated cone shape and a tip made of elastically deformable material fixed to an end of smaller diameter of said body,

[0013] the body comprising through housings distributed around the X axis and parts made of elastically deformable material located in said housings.

[0014] According to the invention, each of the parts made of elastically deformable material comprises at least one peripheral rim for retaining said part in the corresponding housing, said at least one peripheral rim bearing on an internal surface of said body.

[0015] This design of the present invention makes it possible to facilitate the reduction of the size of the ice accreted on the inlet cone of the turbomachine in operation, and therefore amplify the phenomenon of ice deaccretion.

[0016] For this purpose, the parts made of elastically deformable material each incorporate a peripheral rim bearing on the internal surface of the cone body. This peripheral rim makes it possible to firmly and effectively hold the part made of elastically deformable material in the body of the cone (in particular in the corresponding through-housing of the body). In particular, the parts made of elastically deformable material are held in centrifugation by pressing the peripheral rims onto the internal surface of the body of the cone.

[0017] In addition, the parts made of an elastically deformable material, such as elastomer, can deform and move radially (relative to the X axis) when the cone is rotated and without these parts made of elastically deformable material becoming detached from the cone (thanks to the peripheral edges), and also continue to operate with external temperature variations (such as for example a low temperature of -30°C to 15°C). This promotes the embrittlement of the layer of ice accreted on the external surface of the cone. This embrittlement increases the frequency of detachment of the ice and thus reduces the size of the pieces of ice. Thus, the fragmentation and detachment of the ice is better controlled, so that the pieces of detached ice are of a calibrated and acceptable size to potentially be projected onto components downstream of the cone (such as the fan blades of the turbomachine) without damaging them.

[0018] The invention therefore has the advantage of being based on a simple design, offering very high reliability, and with little penalty in terms of cost, size and environmental impact, particularly for the aircraft turbomachine.

[0019] The inlet cone for the aircraft turbomachine according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: - each of the parts made of elastically deformable material comprises a single peripheral edge which extends around the entire perimeter of the part in question; - each of the parts made of elastically deformable material comprises a pad which occupies the entire volume of said through housing and which comprises an external surface aligned with an external surface of said body; - said skate has a general oblong, trapezoidal and / or rectangular shape; - said pad extends over a length of between 50% and 90% relative to a total length of said corresponding part made of elastically deformable material, the lengths being measured substantially in a direction parallel to the external surface of the pad of the part in question; - said at least one peripheral rim has a thickness which is equal to the difference between a thickness of the pad and a thickness of the body, each of these thicknesses being measured in a direction perpendicular to the external surface of the part considered; - each elastically deformable part has a maximum thickness of between 2 mm and 3 mm, the thickness being measured in a direction perpendicular to the internal surface of the body; - the body further comprises a central orifice for the passage of a cylindrical portion of said tip; - said through housings and said parts made of elastically deformable material are three to ten in number, preferably said through housings and said parts made of elastically deformable material are six in number; - said through-housings and said parts made of elastically deformable material are distributed according to one or more annular row(s), respectively, of through-housings and parts made of elastically deformable material; - the tip is one-piece; - the body is made of metallic or composite material.

[0020] The invention also relates to an aircraft turbomachine, comprising an inlet cone according to one of the particularities of the invention. Brief description of the figures

[0021] The invention will be better understood and other details, features and advantages of the invention will appear more clearly on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

[0022] [Fig.l] is a front perspective view schematically representing an inlet cone for an aircraft turbomachine, according to the prior art,

[0023] [Fig.2] is a half schematic view in axial section of an aircraft turbomachine,

[0024] [Fig. 3] is a front perspective view schematically representing an example of an inlet cone according to the invention, for the turbomachine of [Fig. 2],

[0025] [Fig.4] is an axial sectional view schematically showing the inlet cone of [Fig.3],

[0026] [Fig.5] is a rear perspective view schematically showing a tip of the inlet cone of [Fig.3] or 4,

[0027] [Fig.6] is a front perspective view schematically showing the tip and the parts made of elastically deformable material of the inlet cone of [Fig.3] or 4,

[0028] [Fig.7] is a front perspective view schematically representing a variant of the parts made of elastically deformable material of the inlet cone of [Fig.3] or 4.

[0029] Elements having the same functions in different implementations have the same references in the figures. Detailed description of the invention

[0030] By convention in the present application, the terms "inner" and "outer", and "internal" and "external" are defined radially relative to a longitudinal axis X in particular of the engine of the turbomachine. Thus, a cylinder extending along the X axis has an inner face facing the X axis and an outer surface, opposite its inner surface. "Axial" or "axially" means any direction parallel to the X axis and "transversely" or "transverse" means any direction perpendicular to the X axis. Similarly, the terms "upstream" and "downstream" are defined relative to the direction of air circulation in the turbomachine.

[0031] [Fig. 1] has been described in the technical background of the present application, and it illustrates an example of an inlet cone 10 according to the prior art for an aircraft turbomachine 1, which has an upstream tip 11 made of elastically deformable material and a downstream body 12 made of rigid material.

[0032] The present invention applies in a general and non-limiting manner to an aircraft turbomachine 1, illustrated for example in [Fig.2]. The turbomachine 1 may be a turbojet, a turboprop or a turboshaft engine.

[0033] [Fig. 2] shows a double-flow turbomachine 1. This is not, however, limiting and the turbomachine may be of another type, such as for example a turbo- propellant.

[0034] The turbomachine 1 may extend along a longitudinal axis X and comprises from upstream to downstream, in the direction of flow of the gases, a fan 2, one or more compressor stages (for example a low-pressure compressor 3 and a high-pressure compressor 4), a combustion chamber 5, one or more turbine stages (for example a high-pressure turbine 6 and a low-pressure turbine 7), and a gas exhaust nozzle 8. The fan 2, the low-pressure compressor 3 and the low-pressure turbine 7 are connected to a low-pressure shaft extending along the axis X. The high-pressure compressor 4 and the high-pressure turbine 6 are connected to a high-pressure shaft arranged around the low-pressure shaft. The low-pressure turbine 7 drives the low-pressure shaft in rotation, while the high-pressure turbine 6 drives the high-pressure shaft in rotation.

[0035] The turbomachine 1 comprises, in particular upstream of the fan 2, an air inlet cone 10, 20. This cone can be mounted on the fan 2 by means of a ferrule (not shown), preferably by bolt-type fasteners. The ferrule is arranged downstream of the inlet cone and this ferrule is also connected to the low-pressure shaft.

[0036] The inlet cone 10, 20 with the shroud can be connected to the rotor, in other words to the rotating parts of the turbomachine 1. The inlet cone 10, 20 is configured to be driven in rotation about a longitudinal axis which is substantially coincident with the axis X of the turbomachine 1.

[0037] Figures 3 to 7 illustrate an exemplary embodiment of the inlet cone 20 according to the invention.

[0038] With reference to Figures 3 and 4, the inlet cone 20 comprises a body 22 of truncated cone shape and a tip 21 fixed to an end 221 of smaller diameter of the body 22.

[0039] The tip 21 is made of an elastically deformable material. The elastically deformable material of the tip 21 may be made of elastomer, silicone, rubber or polytetrafluoroethylene (PTFE).

[0040] With reference to figures 3 to 5, the tip 21 is arranged upstream of the body 22. The tip 21 may comprise a vertex through which the axis X passes. On the side opposite the vertex, the tip 21 is fixed to the end 221 which may be arranged upstream (hereinafter called upstream end 221), for example substantially along a connecting plane P which is perpendicular to the axis X. For this, the tip 21 may comprise a cylindrical portion 210. This cylindrical portion 210 may be located on the side opposite the vertex of the tip 21.

[0041] The cylindrical portion 210 can be mounted in a central orifice 220 of the body 22. For this, the cylindrical portion 210 can have at least one threaded portion com additional to a tapping of the central orifice 220. Alternatively, the cylindrical portion 210 can simply be fitted into the central orifice 220.

[0042] The tip 21 may be a single piece (i.e., made from one piece). In particular, the tip 21 is formed in a single piece with the cylindrical portion 210, as illustrated in [Fig. 5].

[0043] The body 22 may be made of a metallic material, such as aluminum or titanium, or of a composite material.

[0044] The body 22 may extend between the upstream end 221 and another end 223 arranged downstream (hereinafter called the downstream end 223) and opposite the upstream end 221. This downstream end 223 may be configured to assemble with the shroud of the fan 2 of the turbomachine 1.

[0045] The upstream end 221 may have a generally circular shape, preferably complementary to the tip 21 to be in aerodynamic continuity.

[0046] The body 22 may extend radially between an inner surface 22a and an outer surface 22b opposite this inner surface 22a. The outer surface 22b may be in aerodynamic continuity (or otherwise said aligned) with an outer surface of the tip 21.

[0047] The body 22 may comprise a frustoconical wall 224 and a radial wall 226 (relative to the axis X), this radial wall 226 being connected to the frustoconical wall 224 upstream of the body 22, in particular at the level of the upstream end 221. In the example of FIGS. 3 and 4, the frustoconical wall 224 and radial wall 226 delimit between them a hollow portion 228. This hollow portion 228 may at least partially receive the cylindrical portion 210 of the tip 21.

[0048] The body 22 may have a first thickness E22 measured for example in a direction perpendicular to the internal surface 22a (or the external surface 22b) of the body 22. In particular, this first thickness E22 may correspond to that of the frustoconical wall 224 of the body 22.

[0049] The body 22 comprises through-housings 222 which are distributed around the axis X. The through-housings 222 may be openings. The through-housings 222 may be located on the frustoconical wall 224. The through-housings 222 may be three to ten in number. The through-housings 222 may be distributed according to one or more annular row(s) of through-housings. Each through-housing 222 may have a generally oblong, trapezoidal and / or rectangular shape.

[0050] In the example of Figures 3 and 4, in a non-limiting manner, there are six through-housings 222. These through-housings 222 are distributed around the X axis in a single annular row of through-housings. Alternatively, these through-housings 222 may be distributed in two or more annular rows of through dwellings one after the other.

[0051] The body 22 may comprise the central passage orifice 220. This central orifice 220 is configured for the passage of the cylindrical portion 210 of the tip 21. The central orifice 220 may be located on the radial wall 226, in particular at the upstream end 221. This central orifice 220 may be aligned substantially at the level of the axis X. The central orifice 220 may have a thread to facilitate the fixing of the cylindrical portion 210. The central orifice 220 may have a diameter of at least approximately 10 mm.

[0052] The body 22 comprises parts 23 made of elastically deformable material. The parts 23 and the tip 21 may be made of the same deformable elastic material. These parts 23 are located in the through-housings 222.

[0053] Each part 23 may have a second maximum thickness E23 of between 2 mm and 3 mm. This second thickness E23 is measured in a direction perpendicular to the internal surface 22a of the body 22 (or in other words, in a plane inclined relative to the axis X). The second thickness E23 may be greater than the first thickness E22 of the body 22.

[0054] Each part 23 may have a first total length L23, for example measured substantially in a direction parallel to the internal surface 22a of the body 22 (or in other words in a plane inclined relative to the axis X).

[0055] The parts 23 may be three to ten in number. The parts 23 may be distributed according to one or more annular row(s) of parts.

[0056] In the example of Figures 3 and 4, in a non-limiting manner, there are six parts 23. These parts 23 are distributed around the X axis in a single annular row of parts. Alternatively, these parts 23 may be distributed in two or more annular rows of parts one after the other.

[0057] One of the particularities of the invention is that each of the parts made of elastically deformable material 23 comprises at least one peripheral rim 230 for retaining this part 23 in the corresponding through-housing 222. This peripheral rim 230 bears on the internal surface 22a of the body 22.

[0058] As illustrated in Figures 4, 6 and 7, each of the parts 23 may comprise a single peripheral rim 230 which extends around the entire circumference of the part 23.

[0059] The peripheral rim 230 may have a third thickness E230 measured for example in a direction perpendicular to the internal surface 22a or external surface 22b of the part 23 considered.

[0060] According to another of the particularities of the invention, each of the parts 23 can comprise a pad 236. In the example of the figures, each pad 236 can extend outwardly relative to the peripheral rim 230.

[0061] The pad 236 may comprise an inner surface 236a and an outer surface 236b opposite this internal surface 236a. The internal 236a and external 236b surfaces of the pad 236 may be substantially parallel to, respectively, the internal surface 22a and the external surface 22b of the body 22. The external surface 236a may be aligned with the external surface 22b of the body 22, so as to ensure aerodynamic continuity. The external surface 236b of the pad 236 may correspond substantially and generally to an external surface of the part 23 considered.

[0062] The pad 236 may occupy the entire volume of the through-housing 222. For this purpose, the pad 236 may have a shape complementary to that of the corresponding through-housing 222. For example, the pad 236 has a generally oblong, trapezoidal and / or rectangular shape.

[0063] Figures 3, 4 and 6 illustrate pads 236 of trapezoidal shape. Alternatively, the pads 236 may be of oblong shape, as illustrated in [Fig.7].

[0064] The pad 236 may have a fourth thickness E236, for example measured in a direction perpendicular to the external surface 236b of the part 23 considered (or in other words in a direction perpendicular to the internal surface 22a or external surface 22b of the body 22).

[0065] The pad 236 may have a second length L236 measured in a direction parallel to the external surface 236b (or the internal surface 22a of the body 22). This second length L236 may be between 50% and 90% relative to the first total length L23 of the corresponding part 23. In the example of [Fig.4], the second length L236 represents approximately 75% of the first length L23.

[0066] The third thickness E230 of the peripheral rim 230 may be equal to the difference between the fourth thickness E236 of the pad 236 (or the second maximum thickness E23 of the part 23 considered) and the first thickness E22 of the body 22. Each of these thicknesses E22, E230, E236 may be measured in a direction perpendicular to the external surface 236b of the part 23 considered (or in other words in a direction perpendicular to the internal surface 22a of the body 22). By way of example, the third thickness E230 of the peripheral rim 230 may be between 2 mm and 3 mm.

Claims

Claims

1. Inlet cone (20) for an aircraft turbomachine (1), this inlet cone (20) being configured to be rotated about an axis (X) and comprising a body (22) of frustoconical shape and a tip (21) made of elastically deformable material fixed to an end of smaller diameter of said body (22), the body (22) comprising through-housings (222) distributed around the axis (X) and parts (23) made of elastically deformable material located in said through-housings (222), characterized in that each of the parts (23) made of elastically deformable material comprises at least one peripheral rim (230) for retaining said part (23) in the corresponding through-housing (222), said at least one peripheral rim (230) bearing on an internal surface (22a) of said body (22).

2. Inlet cone according to claim 1, characterized in that each of the parts (23) made of elastically deformable material comprises a single peripheral rim (230) which extends around the entire periphery of the part (23) in question.

3. Inlet cone according to claim 1 or 2, characterized in that each of the parts (23) made of elastically deformable material comprises a pad (236) which occupies the entire volume of said through housing (222) and which comprises an external surface (236b) aligned with an external surface (22b) of said body (22).

4. Inlet cone according to claim 3, characterized in that said pad (236) has a generally oblong, trapezoidal and / or rectangular shape.

5. Inlet cone according to claim 3 or 4, characterized in that said pad (236) extends over a length (L236) of between 50% and 90% relative to a total length (L23) of said part (23) made of corresponding elastically deformable material, the lengths (L23, L236) being measured substantially in a direction parallel to the external surface (236a) of the pad (236) of the part (23) in question.

6. Inlet cone according to any one of claims 3 to 5, characterized in that said at least one peripheral rim (230) has a thickness (E230) which is equal to the difference between a thickness (E236) of the pad (236) and a thickness (E22) of the body (22), each of these thicknesses (E22, E230, E236) being measured in a direction perpendicular to the external surface (236b) of the part (23) considered.

7. Inlet cone according to any one of the preceding claims, characterized in that each elastically deformable part (23) has a maximum thickness (E23) of between 2 mm and 3 mm, the thickness (E23) being measured in a direction perpendicular to the internal surface (22a) of the body (22).

8. Inlet cone according to any one of the preceding claims, characterized in that the body (22) further comprises a central orifice (220) for the passage of a cylindrical portion (210) of said tip (21).

9. Inlet cone according to any one of the preceding claims, characterized in that said through housings (222) and said parts (23) made of elastically deformable material are three to ten in number, preferably said through housings (222) and said parts (23) made of elastically deformable material are C1 V in number

10. □ IA. Inlet cone according to any one of the preceding claims, characterized in that said through housings (23) and said parts (23) made of elastically deformable material are distributed according to one or more annular row(s), respectively, of through housings and parts made of elastically deformable material.

11. Inlet cone according to any one of the preceding claims, characterized in that the tip (21) is in one piece.

12. Inlet cone according to any one of the preceding claims, characterized in that the body (22) is made of metallic material or composite.

13. Aircraft turbomachine (1) comprising an inlet cone (20) according to any one of the preceding claims.

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