Entrance cone made up of several parts

Abstract

Inlet cone formed of several parts Aircraft turbomachine (1) comprising an air inlet cone (10) and a rotor (7) driven in rotation about an axis (X) by a turbine (5), said rotor (7) being connected to the air inlet cone (10) to drive it in rotation. The turbomachine (1) comprises a speed reduction module (8) connected to the rotor (7). The air inlet cone (10) has two distinct parts: a tip (11) and a ferrule (12). The tip (11) is located upstream of the ferrule (12). The ferrule (12) is fixed to the rotor (7) and driven by it to rotate at a speed Vv during turbine (5) operation. The tip (11) is connected to the speed reduction module (8) and, via the module, is driven by the rotor (7) to rotate at a speed Vp different from the speed Vv. Figure to be published with the abbreviation: Figure 1

Description

Title of the invention: Inlet cone formed of several parts TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of turbomachinery, and in particular that of aircraft turbojet engines.

[0002] The present invention relates to an inlet cone for such a turbomachine. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] A turbomachine includes at its upstream end an air inlet supplying a blower and a compressor whose blades are carried by discs attached to a shaft which extends over a major part of the turbomachine and which is capable of being driven into rotation by a turbine.

[0004] An air inlet cone is mounted at the upstream end of this shaft, in particular to deflect part of the airflow which enters the turbomachine towards the fan blades.

[0005] Due to atmospheric conditions encountered during flight, the air inlet cone becomes covered with ice. Being located close to the axis of rotation of the turbomachine, the air inlet cone is subjected to little centrifugal force and this ice only detaches when the mass of accreted ice becomes very large, then generating ice ingestion through the fan which degrades it and reduces the performance of the turbomachine.

[0006] To solve this problem, an existing solution, described in particular in document EP 3983654 on behalf of the applicant, consists of incorporating elastomer sections on the cone. The difference in thermal expansion between the elastomer and the rest of the air inlet cone tends to break up the ice, which increases the frequency of ice detachment and advantageously reduces the size of the ice particles ingested by the blower.

[0007] However, the elastomer wears down rapidly compared to the rest of the air inlet cone and is prone to detaching from it, resulting in frequent and costly maintenance. Furthermore, it is not possible to position the elastomer everywhere on the air inlet cone, and its attachment requires lengthy and complex machining of the cone's external surface.

[0008] The invention aims in particular to find a more durable alternative solution to the problem of ice accumulation on the air inlet cone, that is to say a solution requiring less and simpler maintenance. Summary of the invention

[0009] In the current technique, whether or not it includes elastomer parts, the air inlet cone is mounted at the end of the shaft and is capable of being driven in rotation by it. It therefore rotates at the same speed as the shaft and the blower attached to it.

[0010] The invention offers a solution to the problems mentioned above by providing an air inlet cone in at least two parts, namely a ferrule and a tip located upstream of said ferrule, these two parts being driven in rotation at different speeds. These speeds are different, whether by their magnitude and / or by their positive or negative nature, that is to say, by their direction of rotation.

[0011] One aspect of the invention relates to an aircraft turbomachine comprising a fan, a compressor, an air inlet cone and a rotor capable of being driven in rotation about a longitudinal axis X by a turbine of said turbomachine, said rotor being connected to the fan, the compressor and the air inlet cone to drive them in rotation during the operation of the turbine, where: • the turbomachine also includes a speed reduction module connected to the rotor; • the air inlet cone has two distinct parts, namely a tip and a ferrule, the tip being located upstream of the ferrule; • the shell is fixed to the rotor and configured to be driven in rotation by the latter at a rotational speed Vv during turbine operation; and • the tip is connected to the speed reduction module and, through this module, is configured to be driven in rotation by the rotor at a rotational speed Vp different from the rotational speed Vv of the shell during the operation of the turbine.

[0012] Since the tip and the ferrule are not joined and are driven at different speeds, the ice covering the air inlet cone breaks at the interface between these two parts, which promotes the release of ice accretions forming on the surface of said air inlet cone and also promotes the release of smaller and non-damaging pieces of ice when ingested by the blower.

[0013] According to one aspect of the invention, the tip is configured to be driven in rotation in the opposite direction to that in which the ferrule is driven. Thus, even if the absolute values ​​of the rotational speeds Vp and Vv are identical, the ice covering said air inlet cone breaks at the interface between the tip and the ferrule, which further promotes the release of ice accretions forming on the surface of the air inlet cone, without requiring an elastomer part on the air inlet cone.

[0014] According to another aspect of the invention, the ferrule and the tip are made of aluminum. Thus, these two parts are not susceptible to premature wear.

[0015] According to a further aspect of the invention, the ferrule is secured to the rotor by means of a hollow ferrule shaft, and the tip is connected to the speed reduction module by means of a tip shaft, this tip shaft being at least partially housed within the ferrule shaft and substantially concentric with it. This configuration advantageously allows the turbine to drive the ferrule and the tip at different speeds during its operation.

[0016] According to one aspect of the invention, the tip is cone-shaped or ogive-shaped. This advantageously provides an aerodynamic shape for said tip.

[0017] According to another aspect of the invention, the ferrule is in the shape of a truncated cone or a truncated ogive. This also makes it possible to provide an aerodynamic shape for said ferrule, advantageously in the aerodynamic continuity of the tip.

[0018] According to a further aspect of the invention, the tip is in the shape of a right cone or ogive whose apex is centered on the X axis. This advantageously allows the air entering the turbomachine to be distributed uniformly.

[0019] According to one aspect of the invention, the tip is in the shape of a cone or oblique ogive whose apex is off-center with respect to the X axis. This off-centering advantageously generates an imbalance at the end of the air inlet cone, which increases the stresses applied to the ice, so as to increase the frequency of detachment of the latter.

[0020] According to another aspect of the invention, the tip and the tip shaft are off-center with respect to the X axis. This off-centering advantageously generates an even greater imbalance, particularly advantageous when the mass of accreted ice is very large and / or very difficult to detach.

[0021] According to a further aspect of the invention, the shell and the blower are driven in rotation by the rotor at substantially the same rotational speed Vv. This advantageously allows the shell and the blower to be joined together, for a simpler and less expensive design of the turbomachine.

[0022] According to one aspect of the invention, the air inlet cone further comprises at least one disc attached to the tip, housed within the ferrule, and whose lateral surface is substantially flush with an external face of the ferrule. Each disc creates additional interfaces within the air inlet cone, thereby facilitating the release of ice accretions forming on the surface of said air inlet cone and further reducing the size of the ice fragments thus released. The integration of one or more discs within the air inlet cone, attached to the tip, provides a modular character to said cone of the invention.

[0023] According to another aspect of the invention, the air inlet cone does not have an elastomer part on its external face. This notably reduces maintenance operations on the air inlet cone.

[0024] A further aspect of the invention relates to an aircraft comprising a turbomachine according to the invention as described above. Such an aircraft advantageously benefits from increased reliability and durability for its turbomachine.

[0025] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0026] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0027] [Fig. 1] is a schematic cross-sectional representation of an example of a turbomachine according to the invention.

[0028] [Fig.2] is a schematic cross-sectional representation of an example of a turbomachine according to a variant of the invention where the tip of the air inlet cone is inclined.

[0029] [Fig.3] is a schematic cross-sectional representation of an example of a turbomachine according to a variant of the invention where the tip of the air inlet cone and the tip shaft attached to this tip are eccentric with respect to the X axis of the turbomachine.

[0030] [Fig.4] is a schematic cross-sectional representation of an example of a turbomachine according to a variant of the invention where the air inlet cone further comprises two discs attached to the tip, housed in the ferrule and whose lateral surface is substantially flush with an external face of the ferrule. DETAILED DESCRIPTION

[0031] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0032] By convention, in this application, the terms "upstream" and "downstream" are defined with respect to the direction of airflow in the turbomachine. Similarly, by convention in this application, the terms "inside" and "outside," "lower" and "upper," and "internal" and "external" are defined radially with respect to the longitudinal X-axis of the turbomachine. Thus, a cylindrical part extending along the X-axis of the engine has an inner face facing the longitudinal axis of the turbomachine and an outer surface opposite its inner surface. Finally, "axial" or "axially" means any direction parallel to the X-axis, and "transversely," "transverse," "radially," or "radial" means any direction perpendicular to the X-axis.

[0033] It will be noted that two elements "joined" together are kinematically connected to each other so that any movement of one of these elements also implies an identical movement of the other element, which is not necessarily the case when these two elements are simply* connected to each other.

[0034] [Fig. 1] to [Fig. 4] illustrate a turbomachine 1 in the form of a turbofan engine. This is not, however, limiting and the turbomachine 1 may be of another type, for example a turboprop.

[0035] The turbomachine 1 extends along a longitudinal axis X around which rotates in particular a fan 2 and at least one compressor 3. The turbomachine 1 comprises from upstream to downstream, in the direction of gas flow, a fan 2, one or more stages of compressors 3 (for example a low pressure compressor 3a and a high pressure compressor 3b), a combustion chamber 4, one or more stages of turbine 5 (for example a low pressure turbine 5a and a high pressure turbine 5b), and a gas outlet nozzle 6.

[0036] The blower 2, the low pressure compressor 3a and the low pressure turbine 5a are for example attached to a low pressure shaft 7a extending parallel to the X axis, the low pressure turbine 5b driving the low pressure shaft 7a in rotation when it is operating.

[0037] The high-pressure compressor 3b and the high-pressure turbine 5b are for example attached to a high-pressure shaft 7b extending parallel to the X axis and formed around the low-pressure shaft 7a, the high-pressure turbine 5a driving the high-pressure shaft 7b in rotation when it is operating.

[0038] The low-pressure shaft 7a can for example be provided around a central axis 7c extending along the X axis, these two axes being able to be joined together to form a rotor 7 extending along the X axis.

[0039] Thus, more generally, the turbomachine 1 comprises at least one turbine 5 driving a rotating rotor 7 when it is operating.

[0040] The rotor 7 is preferably attached to a blower 2 and a compressor 3 to drive them in rotation during the operation of the turbine 5.

[0041] According to one embodiment of the invention, the blower 2 and a compressor 3, preferably a low-pressure compressor 3a, are driven in rotation by the rotor 7 at different rotational speeds.

[0042] The turbomachine 1 comprises a speed reduction module 8 having an input 8a, for example upstream, and an output 8b, for example downstream. The input 8a of the speed reduction module 8 is fixed to the rotor 7 and driven by it at a rotational speed Vv when the turbine 5 is operating. The output 8b of the speed reduction module 8 is fixed to an output shaft designated as the tip shaft 9. The speed reduction module 8 is designed to drive the tip shaft 9 at a rotational speed Vp different from the rotational speed Vv of the rotor 7 when the turbine 5 is operating. These two speeds Vv and Vp may differ in their absolute value and / or in their sign, two speeds of opposite sign indicating rotations in opposite directions for the rotor 7 and the tip shaft 9.

[0043] The turbomachine 1 further includes, upstream of the blower 2, an air inlet cone 10 which is characterized in that it has two distinct parts, namely a tip 11 and a ferrule 12, the tip 11 being located upstream of the ferrule 12.

[0044] The tip 11 and the ferrule 12 are, for example, made of metal, preferably aluminum. The air inlet cone 10 preferably does not have any elastomer part either on the external face 11' of the tip 11 or on the external face 12' of the ferrule 12.

[0045] The tip 11 is preferably cone-shaped or ogive-shaped, while the ferrule 12 is preferably truncated cone-shaped or truncated ogive-shaped. At the interface between the tip 11 and the ferrule 12, the respective outer faces 11', 12' of these two parts 11, 12 are preferably flush, so as to maintain the aerodynamic profile of the air inlet cone 10.

[0046] The ferrule 12 is attached to the rotor 7 so that it is configured to rotate at the rotational speed Vv during the operation of the turbine 5. It is also preferably attached to the blower 2, preferably by bolt-type fasteners. Thus, the ferrule 12 and the blower 2 are rotated by the rotor 7 at substantially the same rotational speed Vv.

[0047] The tip 11 is fixed to the tip shaft 9 so that it is configured to rotate at the rotational speed Vp during the operation of the turbine 5. The tip 11 may be integral with the tip shaft 9 or fixed to it. The tip 11 is located upstream of the tip shaft 9, preferably at one of its upstream ends.

[0048] By means of the speed reduction module 8, during the operation of the turbine 5, the tip 11 is configured to be driven in rotation at a rotational speed Vp whose absolute value is different from that of the rotational speed Vv of the ferrule 12, and / or is configured to be driven in rotation in the opposite direction to that in which the ferrule 12 is driven.

[0049] The ferrule 12 is for example secured to the rotor 7 by means of a ferrule shaft 13. This ferrule shaft 13 is preferably hollow and the tip shaft 9 which connects the tip 11 to the speed reduction module 8 is preferably housed in the ferrule shaft 13 and concentric with it, so that the tip shaft 9 can be driven in rotation independently of the ferrule shaft 13, and vice versa.

[0050] According to an embodiment of the invention illustrated in [Fig. 1], the tip 11 is in the form of a right cone or ogive whose apex 14 is centered on the X axis. According to this embodiment, the tip shaft 9 extends along the X axis.

[0051] According to another embodiment of the invention illustrated in [Fig.2], the tip 11 is in the shape of a cone or oblique ogive whose apex 14 is off-center with respect to the X axis. According to this embodiment, the tip shaft 9 extends along the X axis.

[0052] According to an additional embodiment of the invention illustrated in [Fig.3], the tip 11 and the tip shaft 9 are offset with respect to the X axis.

[0053] According to yet another embodiment of the invention illustrated in [Fig. 4], the air inlet cone 10 further comprises at least one disc 15 integral with the tip 11, housed in the ferrule 12, and whose lateral surface 15' is substantially flush with an external face 12' of the ferrule 12. Each disc 15 extends preferably radially around the tip shaft 9. Each disc 15 is preferably integral with the tip shaft 9. Each disc 15 may be integral with the tip shaft 9 or fixed to it. It should be noted that this embodiment can be combined with the three preceding ones.

[0054] Although described through a number of examples, variants and embodiments, the turbomachine according to the invention includes various variants, modifications and improvements which will be obvious to a person skilled in the art, it being understood that these variants, modifications and improvements are part of the scope of the invention.

Claims

Demands

1. Aircraft turbomachine (1) comprising a fan (2), a compressor (3), an air inlet cone (10) and a rotor (7) capable of being driven into rotation about a longitudinal axis (X) by a turbine (5) of said turbomachine (1), said rotor (7) being connected to the fan (2), the compressor (3) and the air inlet cone (10) to drive them into rotation during the operation of the turbine (5), characterized in that: - the turbomachine (1) further comprises a speed reduction module (8) connected to the rotor (7); - the air inlet cone (10) comprises two distinct parts, namely a tip (11) and a ferrule (12), the tip (11) being located upstream of the ferrule (12); - the ferrule (12) is attached to the rotor (7) and configured to be driven in rotation by the latter according to a rotation speed Vv during the operation of the turbine (5);and - the tip (11) is connected to the speed reduction module (8) and, through the latter, is configured to be driven in rotation by the rotor (7) at a rotational speed Vp different from the rotational speed Vv of the shell (12) during the operation of the turbine (5).;

2. Turbomachine (1) according to claim 1, characterized in that the tip (11) is configured to be driven in rotation in the opposite direction to that in which the ferrule (12) is driven.

3. Turbomachine (1) according to claim 1 or 2, characterized in that the ferrule (12) and the tip (11) are made of aluminium.

4. Turbomachine (1) according to any one of the preceding claims, characterized in that the shell (12) is secured to the rotor (7) by means of a hollow shell shaft (13) and in that the tip (11) is connected to the speed reduction module (8) by means of a tip shaft (9), this tip shaft (9) being at least partially housed in the shell shaft (13) and substantially concentric with it.

5. Turbomachine (1) according to any one of the preceding claims, characterized in that the tip (11) is cone-shaped or ogive-shaped.

6. Turbomachine (1) according to any one of the preceding claims, characterized in that the tip (11) is in the shape of an oblique cone or ogive whose apex (14) is off-center with respect to the axis (X).

7. Turbomachine (1) according to claim 4, characterized in that the tip (11) and the tip shaft (9) are offset with respect to the axis (X).

8. Turbomachine (1) according to any one of the preceding claims, characterized in that the shell (12) and the blower (2) are driven in rotation by the rotor (7) substantially at the same rotational speed Vv.

9. Turbomachine (1) according to any one of the preceding claims, characterized in that the air inlet cone (10) further comprises at least one disc (15) integral with the tip (11), housed in the ferrule (12) and whose lateral surface (15') is substantially flush with an external face of the ferrule (12).

10. Aircraft comprising a turbomachine (1) according to any one of the preceding claims.

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