Inlet casing of a turbomachine

Abstract

The present invention relates to an inlet casing (2) of a turbomachine (1) comprising: - a first shell (5, 6) in which a plurality of through-orifices are formed; - a second shell (6, 5); - arms (7) extending radially from the first shell (5, 6) to the second shell (6, 5), each arm (7) having a first end (12, 18) inserted into a corresponding through-orifice (13, 18) of the first shell (5, 6); and - gussets (14, 17), each gusset (14, 17) being monolithic with one of the first shell (5) and the first end (12, 18) of the corresponding arm (7) and being fixed to the other of the first shell (5, 6) and the first end (12, 18) of the corresponding arm (7). Figure for abstract: Fig. 1

Description

Title of the invention: Inlet casing of a turbomachine FIELD OF THE INVENTION

[0001] The present application relates generally to the field of turbomachines, and more particularly to the inlet casing of turbomachines. STATE OF THE ART

[0002] A turbomachine may comprise an inlet casing and a compression section generally comprising a low pressure compressor and a high pressure compressor.

[0003] The role of the inlet casing is to ensure continuity of the flow path at the air inlet sleeve of the turbomachine and to guide the air flow towards the compression section which is located immediately downstream. It also provides a structural function and can, if necessary, support the axial stop of an engine bearing.

[0004] The inlet casing comprises for this purpose a plurality of arms extending radially between an inner hub and an outer shell. The arms are fixed on the inner hub and the outer shell by means of gussets added and fixed at the radial ends of the arms. However, the arms and the gussets being placed in the air flow, they disturb the air flow entering the compressor. Statement of the invention

[0005] An aim of the present application is to remedy the aforementioned drawbacks, by proposing an inlet casing making it possible to reduce the pressure losses in the aerodynamic vein while ensuring its structural function and guiding the air flow.

[0006] For this purpose, according to a first aspect, there is proposed an inlet casing of a turbomachine comprising: - a first ferrule having a first surface and a second surface, a plurality of through-holes being formed in the first ferrule; - a second ferrule having a first surface and a second surface; - arms extending radially from the second surface of the first ferrule to the first surface of the second ferrule, each arm having a first end inserted into a corresponding through-hole of the first ferrule; and - gussets, each gusset being monolithic with one of the first surface of the first ferrule and the first end of the corresponding arm and being fixed to the other of the first surface of the first ferrule and the first end of the corresponding arm.

[0007] Certain preferred but non-limiting features of the inlet housing according to the first aspect are the following, taken individually or in combination: - each gusset is monolithic with the second surface of the first ferrule and is fixed on the first end of the corresponding arm in order to connect the arm to the first ferrule; - a plurality of through slots are formed in the second ferrule, each through slot being open on a downstream edge of the second ferrule and configured to receive a second end of a corresponding arm; - the inlet casing further comprises additional gussets added and fixed on the second end of the arms and on the second surface of the second ferrule; - the additional gussets comprise a lower surface portion configured to be attached and fixed to an upper surface face of the arm and an upper surface portion configured to be attached and fixed to an upper surface face of the arm; - the inlet casing further comprises an additional ferrule attached and fixed to a downstream part of the second ferrule; and / or - the first ferrule extends radially inside the second ferrule.

[0008] According to a second aspect, there is provided a turbomachine comprising an inlet casing according to the first aspect and an aircraft comprising at least one such turbomachine.

[0009] According to a third aspect, there is provided a method of manufacturing an inlet casing of a turbomachine according to the first aspect comprising the following steps: - forming a first shell and arms, one of the second surface of the first shell and a first end of the arms being monolithic with gussets; - fixing the other of the second surface of the first ferrule and the first end of the corresponding arm with the gussets, for example by brazing or welding; - assemble a second end of the arms with the second ferrule; and - fix the second end of the arms with the second ferrule, for example using additional gussets added and fixed on the second surface of the second ferrule. DESCRIPTION OF FIGURES

[0010] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0011] [Fig. 1] is a perspective view of an exemplary inlet housing according to one embodiment of the invention;

[0012] [Fig.2] is a partial view from below of the inner hub of the input housing of the [Fig.l], on which is visible an example of the realization of a monolithic gusset with the internal hub;

[0013] [Fig.3] is a partial view of the input housing of [Fig.2] showing the inner hub, arms and an outer ferrule;

[0014] [Fig.4] is a perspective view of the additional ferrule of [Fig.l];

[0015] [Fig.5] is a partial view of the inlet casing of [Fig.2] on which are visible the inner hub, an arm, the outer ferrule, an additional gusset and the additional ferrule;

[0016] [Fig. 6] illustrates an example of a turbomachine comprising an inlet casing according to an embodiment of the invention; and

[0017] [Fig.7] illustrates an example of an aircraft which may comprise at least one turbomachine according to an embodiment of the invention.

[0018] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0019] A turbomachine 1 (illustrated as an example in [Fig.6]) has a main direction extending along a longitudinal axis X and typically comprises, from upstream to downstream in the direction of gas flow, an inlet casing 2 and a compression section 3 generally comprising a low-pressure compressor and a high-pressure compressor.

[0020] The inlet casing 2 therefore extends upstream of the compression section 3 of the turbomachine 1, immediately downstream of an inlet cone 4 of the turbomachine 1.

[0021] In the present application, upstream and downstream are defined relative to the normal flow direction of the gas in the inlet casing 2 and through the turbomachine 1. Furthermore, the X axis of the inlet casing 2 is called its extension X axis, which corresponds substantially to an X axis of symmetry of its internal hub 5. The axial direction corresponds to the direction of the X axis and a radial direction is a direction perpendicular to this X axis and passing through it. Furthermore, the circumferential (or lateral) direction corresponds to a direction perpendicular to the X axis and not passing through it. Unless otherwise specified, internal (respectively, interior) and external (respectively, exterior), respectively, are used with reference to a radial direction so that the internal part or face of an element is closer to the X axis than the external part or face of the same element.

[0022] The inlet casing 2 ([Fig.l]) comprises a first ferrule 5 and a second ferrule 6 which are substantially coaxial, as well as arms 7 which extend radially between the first and second ferrules 5, 6. The first ferrule 5 extends radially inside the second ferrule 6. The first ferrule 5 therefore corresponds to an internal hub 5 while the second ferrule 6 corresponds to an external ferrule 6.

[0023] The inner hub 5 comprises a first surface 8 ([Fig.2]), or inner surface, and a second surface 9 ([Fig.5]), or outer surface. The outer shell 6 ([Fig.3]) comprises a first surface 10, or inner surface, and a second surface 11, or outer surface. The outer surface 9 of the inner hub 5 and the inner surface 10 of the outer shell 6 face each other and are in contact with the gas flow entering the turbomachine 1. The inner surface 8 of the inner hub 5 and the outer surface 11 of the outer shell 6 are not located in the gas flow. The external surface 11 of the external shell 6 faces, for example, the nacelle of the turbomachine 1 and can in particular be positioned opposite a collector 27 ([Fig.l]) of the inlet casing 2. The internal surface 8 of the internal hub 5 can in particular face a set of bearings 29 ([Fig.6]) supporting the drive shaft of the compression section 3.

[0024] In order to reduce pressure losses in the air inlet stream, each arm 7 ([Fig.l]) has a first end 12, or lower end, which is inserted into a corresponding through-hole 13 formed in the internal hub 5. In addition, the inlet casing 2 comprises gussets 14, 17 ([Fig.6]). One of the gussets 14, 17 of the arm is monolithic with one of the surface 8, 11 and the corresponding end 12, 18 of the arm 7, being fixed on the other of the surface 8, 11 5, 6 and the end 12, 18 of the arm 7. First form of realization

[0025] In a first embodiment, it is the gussets 14 located in the lower part of the arms 7 which are monolithic with the internal surface 8 of the internal hub 5 and which are fixed on the first end 12 of the corresponding arm 7. The gussets 14 are therefore placed outside the flow vein passing through the inlet casing 2 in the lower part, which makes it possible to eliminate the pressure losses linked to the fixing of the arms 7 on the internal hub 5 without adverse impact on the integration, the mechanical strength or the aerothermal functions of the inlet casing 2.

[0026] The shape of the through-orifice 13 is complementary to the shape of the lower end 12 of the arm 7 in order to receive the lower end 12 with adjustment and to block the passage of air from the flow vein towards the internal surface 8 of the internal hub 5. The through-orifices 13 therefore extend substantially axially. Furthermore, the gussets 14 (illustrated in [Fig.2]) comprise a wall 15 extending radially inwardly from the inner surface 8 of the inner hub 5. The wall 15 of each gusset 14 extends radially inwardly from the through-hole 13 so that, when the lower end 12 of the arm 7 is inserted into the through-hole 13, a leading edge, a trailing edge, a pressure-side wall and an extrados wall of the arm 7 come into contact with the wall 15 of the corresponding gusset 14.The gusset 14 may in particular comprise a protuberance 16, extending from a downstream edge of the through-orifice 13 and configured to come into contact. contact with the trailing edge of the arm 7. The shape of the protuberance 16 is complementary to the shape of the trailing edge of the arm 7 in order to ensure this contact. The shape of the wall 15 is further complementary in the upstream part to the shape of the leading edge of the arm 7.

[0027] In the upper part, the arms 7 are then fixed to the outer ferrule 6 by additional gussets 17 (see [Fig.5]), which are added and fixed on an outer end of the arms 7. For this purpose, each arm 7 has a second end 18 (see [Fig.3]), or upper end, which is inserted into a corresponding through slot 19 formed in the outer ferrule 6. Preferably, each slot 19 is open on a downstream end of the outer ferrule 6 in order to allow the axial insertion of the upper end 18 of the arm 7 into the slot 19 after its fixing to the inner hub 5. The shape of the slot 19 is complementary to the shape of the upper end 18 of the arm 7 in order to receive with adjustment the upper end 18. The slots 19 therefore extend substantially axially.

[0028] Each additional gusset 17 may comprise an intrados portion 20 configured to be attached and fixed to an intrados face of the arm 7 and the external surface 11 of the external shell 6, and an extrados portion 21 configured to be attached and fixed to an extrados face of the arm 7 and the external surface 11 of the external shell 6. The intrados portion 20 and the extrados portion 21 are therefore bent. Furthermore, they may be separate and distinct in order to facilitate their assembly on the arms 7 and the external shell 6. They are then attached and fixed separately on the arm 7.

[0029] Here again, the gussets 17 are therefore placed outside the flow path passing through the inlet casing 2, which makes it possible to eliminate the pressure losses linked to the fixing of the arms 7 on the external shell 6.

[0030] In addition, the inlet casing 2 comprises an additional ferrule 22 (see figures 1 and 4) added and fixed on the downstream end of the second ferrule 6 in order to block the upper end 18 of the arms 7 relative to the external ferrule 6. In one embodiment, the additional ferrule 22 is fixed on the external ferrule 6 by welding, brazing or bolted connection. For this, the additional ferrule 22 comprises an upstream edge 24 extending radially from an upstream end and configured to be fixed on a downstream edge 23 extending radially from the external ferrule 6, for example from its downstream end. The slots 19 of the external ferrule 6 therefore open onto the upstream edge 24 of the additional ferrule 22. In other words, the upstream edge 24 of the additional ferrule 22 forms an axial stop for the arms 7 and also prevents the passage of air towards the external ferrule 6.

[0031] Optionally, the additional ferrule 22 comprises a plurality of through holes 25, formed near a downstream edge 26 of the additional ferrule 22, in the extension of the arms 7, in order to be able to install parts adjacent to the inlet casing 2.

[0032] The inlet casing 2 may further comprise a collector 27 ([Fig.l]), attached and fixed to the external surface 11 of the external shell 6, for example by welding or brazing. The collector 27 may in particular comprise an annular gutter having an upstream annular radial flange configured to be fixed to an upstream edge 28 of the external shell 6, an annular wall substantially coaxial with the axis X and extending at a distance from the external surface 11 of the external shell 6, and a downstream annular radial flange configured to be fixed to one of the downstream edge 23 of the external shell 6 and the upstream edge 24 of the additional shell 22. Preferably, the downstream annular radial flange is fixed to the upstream edge 24 of the additional shell 22. Second embodiment

[0033] In a second embodiment, it is the gussets 17 which are monolithic with the upper end 18 of each arm 7. The upper end 18 of the arms is then inserted into a corresponding through slot 19 of the outer shell 6. In addition, each gusset 17 is fixed on the external surface 11 of the outer shell 6 in order to connect the arm 7 to the outer shell 6. The gussets 17 located in the upper part of the arms 7 are therefore placed outside the flow path passing through the inlet casing 2, which makes it possible to eliminate the pressure losses linked to the fixing of the arms 7 on the outer shell 6 without adverse impact on the integration, the mechanical strength or the aerothermal functions of the inlet casing 2. Preferably, the gussets 17 are fixed by welding or brazing on the external surface 11 of the outer shell 6.Each gusset 17 may for example comprise a curved plate extending circumferentially from the upper end 18 of the corresponding arm 7, so as to match the curved shape of the external surface 11 of the external shell 6. The gussets 17 extend in a direction away from an internal cavity of the arms: the internal cavity of the arms can therefore be open on their upper end 18 because it is not closed by the gussets 17. In addition, the shape of the slot 19 is complementary to the shape of the upper end 18 of the arm 7 in order to receive with adjustment the upper end 18 and to block the passage of an air flow towards the external surface 11 of the external shell 6. The slots 19 therefore extend substantially axially.

[0034] It will be noted that, in this second embodiment, the inner hub 5 may also comprise gussets 14, which may be monolithic with the lower surface 8 of the inner hub 5 and receive the lower end 12 of the arms 7 through a through-hole 13, as described above. Furthermore, in this embodiment, the inlet casing 2 may comprise only the outer ferrule 6 (and no additional ferrule), in which case the through-holes may be formed in the external ferrule 6, being open on the slots 19.

[0035] Method of assembling the inlet casing 2 according to the first embodiment

[0036] The inner hub 5, the arms 7 and the outer ferrule 6 are manufactured separately. A plurality of through holes 13 are formed in the inner hub 5. Preferably, the number of through holes 13 formed in the inner hub 5 is equal to the number of arms 7 of the input casing 2.

[0037] In addition, the internal hub 5 is formed integrally and in a single piece with the gussets 14, for example by additive manufacturing or forging ([Fig.2]). The gussets 14 are therefore monolithic with the internal hub 5.

[0038] The lower end 12 of each arm 7 is then introduced into a corresponding through-hole 13, then fixed in position, for example by welding or brazing.

[0039] Through slots 19 are formed in the outer shell 6. The number of through slots 19 is equal to the number of arms 7 of the input casing 2.

[0040] The upper end 18 of each arm 7 is placed in a corresponding slot 19 of the outer ferrule 6 ([Fig.3]). It will be noted that this step can be carried out after fixing the arms 7 on the inner hub 5 (in which case the outer ferrule 6 is attached and slid onto the upper end 18 of the arms 7). Alternatively, the outer ferrule 6 can be put into position around the inner hub 5 by suitable tooling before fixing the arms 7. When fixing the arms 7 to the inner hub 5, they are then simultaneously inserted into the through holes 13 and into the slots 19.

[0041] The additional gussets 17 are attached and fixed to the upper end 18 of the arms 7 ([Fig.5]), for example by welding or brazing.

[0042] The additional ferrule 22 is then added and fixed to the external ferrule 6, for example by placing the upstream edge 24 of the additional ferrule 22 against the downstream edge 23 of the external ferrule 6 ([Fig.5]). The fixing of the additional ferrule 22 to the external ferrule 6 can be carried out by welding, brazing or mechanically using bolted connections.

[0043] A collector 27 can then be attached and fixed to the external ferrule 6 and, if necessary, the additional ferrule 22 ([Fig.l]).

[0044] The inlet casing 2 thus obtained can then be added and fixed in a turbomachine 1, in particular an aircraft 100, for example by bolting the downstream edge 26 of the additional shell 22 onto an edge of the compressor casing of the compression section.

[0045] Method of assembling the inlet casing 2 according to the second embodiment

[0046] The inner hub 5, the arms 7 and the outer ferrule 6 are manufactured separately.

[0047] The gussets 17 and the arms 7 are formed integrally and in a single piece, for example by additive manufacturing, typically by selective laser melting or electron beam melting, so as to obtain a monolithic part integrating gussets 17.

[0048] Through slots 19 are formed in the outer ferrule 6.

[0049] Through holes 13 are formed in the inner hub 5. Preferably, the number of through holes 13 formed in the inner hub 5 and of through slots 19 formed in the outer shell 6 are equal to the number of arms 7 of the input casing 2.

[0050] In addition, the internal hub 5 is formed integrally and in a single piece with the additional gussets 14, around the through holes 13. The additional gussets 14 are therefore monolithic with the internal hub 5.

[0051] The inner hub 5 and the outer ferrule 6 are placed in a tool in order to position the inner hub 5 radially inside the outer ferrule 6 so that each through hole 13 is aligned with a through slot 19.

[0052] The arms 7 are then inserted into the through slots 19 until their lower end 12 enters a corresponding through orifice 13 and their gusset 17 comes into abutment against the external surface 11 of the external ferrule 6. The lower end 12 of the arms is then fixed to the additional gussets 14 and then the gussets 17 are fixed to the external ferrule 6, for example by welding or brazing.

[0053] A collector 27 can then be attached and fixed to the external ferrule 6.

[0054] The inlet casing 2 thus obtained can then be attached and fixed in a tur- machine 1, in particular of aircraft 100, for example by bolting the external shell 6 onto an edge of the compressor casing of the compression section.

Claims

Claims

1. Inlet casing (2) of a turbomachine (1) comprising: - a first shell (5) having a first surface (8) and a second surface (9), a plurality of through-holes being formed in the first shell (5); - a second shell (6) having a first surface (10) and a second surface (11), a plurality of through-slots (19) being formed in the second shell (6); - arms (7) extending radially from the second surface (9) of the first shell (5) to the first surface (10) of the second shell (6), each arm (7) having a first end (12) inserted into a corresponding through-hole (13) of the first shell (5);and - gussets (14), each gusset (14) being monolithic with one of the first surface (8) of the first ferrule (5) and the first end (12) of the corresponding arm (7) and being fixed on the other of the first surface (8) of the first ferrule (5) and the first end (12) of the corresponding arm (7); the inlet casing (2) being characterized in that each through slot (19) is open on a downstream edge (23) of the second ferrule (6) and configured to receive a second end (18) of a corresponding arm (7).;

2. An inlet housing (2) according to claim 1, wherein each gusset (14) is monolithic with the second surface (9) of the first ferrule (5) and is fixed to the first end (12) of the corresponding arm (7) in order to connect the arm (7) to the first ferrule (5).

3. Inlet casing (2) according to claim 1 or 2, further comprising additional gussets (17) attached and fixed to the second end (18) of the arms (7) and to the second surface (11) of the second ferrule (6).

4. Inlet casing (2) according to claim 3, wherein the additional gussets (17) comprise an intrados portion (20) configured to be attached and fixed to an intrados face of the arm (7) and an extrados portion (21) configured to be attached and fixed to an extrados face of the arm (7).

5. Inlet casing (2) according to one of claims 1 to 4, further comprising an additional ferrule (22) attached and fixed to a part

6.

7.

8.

9. downstream (23) of the second ferrule (6). Inlet casing (2) according to one of claims 1 to 5, in which the first ferrule (5) extends radially inside the second ferrule (6). Turbomachine (1) comprising an inlet casing (2) according to one of claims 1 to 6. Aircraft (100) comprising at least one turbomachine (1) according to claim 7. Method for manufacturing an inlet casing (2) of a turbomachine (1) according to one of claims 1 to 6 comprising the following steps: - forming a first shell (5) and arms (7), one of the second surface (9) of the first shell (5) and a first end (12) of the arms (7) being monolithic with gussets (14); - fixing the other of the second surface (9) of the first ferrule (5) and the first end (12) of the arm (7) corresponding to the gussets (14), for example by brazing or welding; - assembling a second end (18) of the arms (7) with the second ferrule (6); and - fixing the second end (18) of the arms (7) with the second ferrule (6), for example using additional gussets (17) added and fixed on the second surface (9) of the second ferrule (6).

Images