AIRCRAFT TURBOMACHINE INLET CONE

Abstract

The invention relates to an inlet cone (9) for an aircraft turbomachine fan comprising a rotation-locking device including a pusher (3) slidably mounted in an orifice (20), said main portion (30) carrying first rotation-locking means (31) of said cone adapted to engage against second rotation-locking means (12), said first rotation-locking means (31) being movable between at least: an engaged position between the first (31) and second (12) rotation-locking means; and a disengaged position between the first (31) and second (12) rotation-locking means. The transition from the engaged position to the disengaged position is effected by translation of said pusher (3) from an initial position in which one end (300) is flush with an external surface of said inlet cone (9) to a retracted position in which said end (300) is pushed into said orifice (20). Figure 3.

Description

Title of the invention: AIRCRAFT TURBOMACHINE INTAKE CONE Scope of the invention

[0001] The present invention relates to the field of turbomachinery fans, particularly for aircraft turbojet engines. More specifically, the invention concerns an inlet cone for such a turbomachine. Prior art

[0002] As illustrated in [Fig. 1], a state-of-the-art turbomachine includes at its upstream end an air inlet for supplying a blower via an airflow F. This blower comprises a blower disk 104 centered on the longitudinal axis X, which is also the axis of rotation, and blower blades 105 mounted on the blower disk 104.

[0003] The air flow F entering this turbomachine through the air inlet, in a direction corresponding to the main direction of gas flow within the turbomachine, is deflected by an inlet cone towards the fan blades 105, then is separated into a primary flow passing through the compressor supplying the combustion chamber of the turbojet and a secondary flow which flows around the compressor.

[0004] This inlet cone is centered on the axis of rotation and is driven in rotation with the blower disk. It can either be made in one piece as illustrated in Figure 5 of document EP2028375, or in several adjacent parts as illustrated in [Fig. 1] and [Fig. 3] of document EP2028375. For example, an upstream part 101 extending from the apex of the cone, otherwise called the upstream cone, and a downstream part 102, otherwise called the downstream ferrule, adjacent to the blower blades and conventionally carrying balancing weights.

[0005] In order to keep the upstream and downstream sections fixed, and these two sections on the blower disc or on a connecting piece to the blower disc, the technique currently employed consists of fixing the upstream cone to the downstream ferrule by means of a plurality of screws 106 regularly spaced around the periphery of the cone. These screws, inserted into longitudinal recesses 103, however, present an aerodynamic disadvantage because the recesses are exposed and cause local turbulence that disrupts the incoming airflow.

[0006] To counter this drawback, a solution was proposed in document FR 2 908 827. According to this technique, the turbomachine inlet cone is fixed to the downstream shell by means of several screws, these screws being positioned at the level of orifices formed at the bottom of an annular groove located near a downstream end. In order not to disrupt the aerodynamics of the turbomachine, this groove is then covered by sealing means having an external surface aligned with that of the cone.

[0007] However, such a solution is not optimal because the different parts must be perfectly calibrated, in particular the sealing means and the orifice, so as to fit together without leaving any potential sources of disturbance to the incoming airflow.

[0008] Furthermore, a disadvantage of such a solution is that it requires a relatively large number of parts for its implementation, which generates significant complexity and cost, which is also unsatisfactory.

[0009] Another disadvantage of such a solution is that it proves relatively complex to dismantle because dismantling the upstream cone requires prior dismantling of a plurality of parts, which can cause premature wear of various parts as well as possible loss of parts, which is not satisfactory. Description of the invention

[0010] The invention aims to remedy at least in part the aforementioned drawbacks relating to prior art techniques.

[0011] To this end, the invention relates to an inlet cone for an aircraft turbomachine fan mounted to rotate about a longitudinal axis X, comprising an upstream cone carrying a vertex S and a downstream ferrule, the upstream cone and the downstream ferrule jointly forming the external surface of said inlet cone.

[0012] According to the invention, the inlet cone further comprises a rotation-locking device including a pusher having a main portion mounted to slide along a radial axis R orthogonal to the longitudinal axis X in an orifice formed in said downstream ferrule, said main portion carrying first rotation-locking means for said upstream cone adapted to engage against second rotation-locking means provided at one end of a support platform for said upstream cone, said first rotation-locking means being movable between at least: - an engaged position in which said first means of rotational stopping are in contact with said second means of rotational stopping so as to block a rotation of said upstream cone along said longitudinal axis X; - a disengaged position in which said first means of rotational arrest are radially separated from said second means of rotational arrest,

[0013] the passage of said first rotational stopping means from the engaged position to the disengaged position being done by translation of said pusher from an initial position in which one end of said main portion is flush with said external surface of said inlet cone to a retracted position in which said end is pushed into said orifice.

[0014] Thus, the invention proposes a new and inventive approach making it possible to resolve at least in part some of the disadvantages of the prior art.

[0015] In particular, the invention makes it possible to keep the upstream cone fixed relative to the downstream ferrule by means positioned inside to provide an external inlet cone surface which has a smooth surface, and to facilitate the dismantling of the various components of this inlet cone when necessary, for example for maintenance or replacement of parts, by the implementation of mechanically simple and therefore inexpensive parts.

[0016] It should be noted that the translation of the pusher can, preferably, be caused by pressing on the end of the pusher.

[0017] According to a particular aspect of at least one embodiment of the invention, said first means of rotational stopping and said second means of rotational stopping have a substantially complementary shape.

[0018] This allows the contact surfaces between the first rotational stopping means and the second rotational stopping means to be optimized.

[0019] In this case, according to a particular aspect of at least one embodiment of the invention, said first means of rotational stopping and said second means of rotational stopping have a toothed shape.

[0020] According to a particular aspect of at least one embodiment of the invention, said pusher further comprises a secondary portion monobloc with the main portion and extending in a plane orthogonal to said main portion, said secondary portion being intended to slide in a housing formed in said downstream ferrule so that, in the initial position of said pusher corresponding to an engaged position of said first stopping means in rotation, a superior surface of said secondary portion comes to lock in translation along said radial axis R against an upper wall of said housing.

[0021] This ensures axial stability of the pusher during its translational movement, and also ensures that the pusher is flush with said external surface of said inlet cone in the initial position.

[0022] According to a particular aspect of at least one embodiment of the invention, said rotation-locking device further comprises a translation-locking ring housed at a lower end of said housing so that, in the retracted position of said pusher corresponding to a disengaged position of said first rotational stopping means, a lower surface of said secondary portion comes to block in translation along said radial axis R against said translational stopping ring.

[0023] This prevents the pusher from coming out of the orifice by pushing in beyond a retracted position sufficient for the first rotation stop means to be radially separated from the second rotation stop means.

[0024] According to a particular aspect of at least one embodiment of the invention, said rotation locking device further comprises at least one return spring provided between said translation stop ring and said lower surface of said secondary portion, said at least one return spring being intended to return said pusher to its initial position.

[0025] According to a particular aspect of at least one embodiment of the invention, said main portion has a substantially cylindrical shape extending along said radial axis R, and said pusher has indexing means intended to block a rotation of said main portion along said radial axis.

[0026] According to a particular aspect of at least one embodiment of the invention, the inlet cone further comprises sealing means provided between the pusher and the orifice and / or between said pusher and said housing.

[0027] Such sealing means make it possible to protect the blocking device from possible external aggressions, for example from water or dust, and therefore from a potential deterioration of the mechanism.

[0028] According to a particular aspect of at least one embodiment of the invention, said rotation-locking device comprises a plurality of pushers, each provided with a main portion mounted to slide along a radial axis R orthogonal to the longitudinal axis X in an orifice formed in the downstream ferrule, the orifices being regularly distributed angularly on the surface of the downstream ferrule.

[0029] According to a particular aspect of at least one embodiment of the invention, the support platform further comprises a section having a threaded upper face intended to screw onto a tapped hole formed on a portion of a lower face of said downstream ferrule.

[0030] The invention also relates to a fan for an aircraft turbomachine mounted to rotate about a longitudinal axis X, the fan comprising an inlet cone according to one of the aforementioned embodiments.

[0031] The invention also relates to an aircraft turbomachine comprising a blower according to the aforementioned embodiment.

[0032] According to one aspect of at least one embodiment, the turbomachine is an aircraft turbojet engine. Presentation of the figures

[0033] The invention, as well as its various advantages, will be more easily understood in the light of the following description of an illustrative and non-limiting embodiment thereof, and the accompanying drawings, among which:

[0034] [Fig. 1] already described, is a schematic side view in cross-section illustrating a state-of-the-art inlet cone; [Fig.2] represents a schematic view of a turbofan engine, in longitudinal section; [Fig. 3] is a side view in cross-section schematically illustrating an inlet cone according to an embodiment of the invention, the first rotation-stopping means being in the engaged position, the pusher being in the initial position, and [Fig.4] is a side view in cross-section schematically illustrating an inlet cone according to an embodiment of the invention, the first means of stopping rotation being in the disengaged position, the pusher being in the retracted position. Description of the implementation methods

[0035] It should be noted that, throughout the description, the terms "upstream" and "downstream" are to be considered in terms of the main direction of gas flow within the turbomachine, and therefore at their arrival on the external surface of the inlet cone by means of the air flow F.

[0036] Furthermore, throughout the description, an axial direction corresponds to the direction of the longitudinal axis X and a radial direction is a direction orthogonal to the longitudinal axis X and intersecting the longitudinal axis X. Therefore, the direction along the axis R corresponds to a radial direction.

[0037] Similarly, the adjectives "interior" (or "internal") and "exterior" ("or external") are used with reference to this radial direction so that the interior part of an element is, along this radial direction, closer to the longitudinal axis X than the exterior part of the same element.

[0038] With reference first to [Fig. 2], an aircraft turbomachine 901 is shown, according to a preferred embodiment of the invention. This is a twin-spool, turbofan engine. However, it could be a turbomachine of another type, for example a turboprop, without departing from the scope of the invention. The turbofan engine 901 has a central longitudinal axis X around which its various components extend. It comprises, from upstream to downstream along a principal direction 905 of gas flow through this turbofan engine, a fan 903, a low-pressure compressor 904, a high-pressure compressor 906, a combustion chamber 911, a high-pressure turbine 907, and a low-pressure turbine 908.

[0039] Conventionally, after passing through the blower, the air splits into a central primary flow 912a and a secondary flow 912b that surrounds the primary flow. The primary flow 912a flows into a main gas circulation channel 914a, passing through the compressors 904, 906, the combustion chamber 911, and the turbines 907, 908. The secondary flow 912b flows into a secondary channel 914b, radially delimited outwards by an engine casing, surrounded by a nacelle 909. The compressors 904, 906 and the turbines 907, 908 are formed by alternating moving wheels, called rotor wheels, and fixed wheels, called stator wheels.

[0040] The principle of the invention is based on the implementation of an inlet cone comprising a rotation blocking device, at least some of whose components are movable in translation along a radial axis R orthogonal to the axis of rotation X so as to move from a position in which the upstream cone is blocked in rotation relative to the downstream ferrule to a position in which the upstream cone is no longer blocked in rotation relative to the downstream ferrule.

[0041] As illustrated in these figures, the inlet cone 9 is adapted for an aircraft turbomachine fan mounted movably to rotate about an axis of rotation X intended to be supplied by means of an airflow F.

[0042] The blower comprises a blower disk centered on the axis of rotation X, and blower blades attached to the blower disk.

[0043] This inlet cone comprises an upstream cone 1 bearing a vertex S and a downstream ferrule 2. This upstream cone 1 and this downstream ferrule 2 together form the external surface of the inlet cone 9.

[0044] It should be noted that the downstream ferrule 2 is equipped with balancing weights that can be placed regularly on its inner perimeter.

[0045] The inlet cone 9 further includes a rotation-locking device. This rotation-locking device includes a pusher 3 having a main portion 30 mounted to slide along a radial axis R orthogonal to the longitudinal axis X in an orifice 20 formed in the downstream ferrule 2.

[0046] This main portion 30 here has a substantially cylindrical shape extending along the radial axis R.

[0047] So that this main portion 30 does not pivot about the radial axis R, the pusher of this embodiment has indexing means (not shown), intended to block a rotation of the main portion 30 about the radial axis R.

[0048] Furthermore, in the illustrated embodiment, the pusher 3 comprises a secondary portion 32 monobloc with the main portion 30 and extending in a plane orthogonal to the main portion 30. This secondary portion is intended to slide in a housing 21 formed in the downstream ferrule 2.

[0049] More particularly, this housing 21 is formed here in continuity with the orifice 20 and has a diameter greater than the diameter of the orifice 20.

[0050] In order to protect the blocking device from the external environment, for example from water or dust, and therefore from potential deterioration of the mechanism, the inlet cone 9 according to this embodiment further includes sealing means provided between the pusher 3 and the orifice 20 and between the pusher 3 and the housing 21.

[0051] According to one variant, the inlet cone could include sealing means provided between the pusher 3 and the orifice 20 or between the pusher 3 and the housing 21.

[0052] According to the invention, the main portion 30 carries first rotational stopping means 31 of the upstream cone 1 which are able to engage against second rotational stopping means 12 provided at one end of a support platform 11 of the upstream cone 1.

[0053] These first rotational stopping means 31 are mobile between at least: - an engaged position in which the first rotational stopping means 31 are in contact with the second rotational stopping means 12 so as to block a rotation of the upstream cone 1 along the longitudinal axis X; - a disengaged position in which the first rotational stopping means 31 are radially separated from the second rotational stopping means 12.

[0054] Fig. 3 illustrates the first rotational stopping means which are in the engaged position while Fig. 4 illustrates the first rotational stopping means which are in the disengaged position.

[0055] According to the invention, the transition of the first rotation stop means 31 from the engaged position to the disengaged position is done by translation of the pusher 3 from an initial position in which an end 300 of the main portion 30 is flush with the external surface of the inlet cone 9 to a retracted position in which the end 300 is pushed into the orifice 20.

[0056] Fig. 3 illustrates the pusher in the initial position while Fig. 4 illustrates the pusher in the retracted position.

[0057] In this embodiment, the first rotational stopping means 31 and the second rotational stopping means 12 have a substantially complementary shape, so as to optimize the contact surfaces between the first rotational stopping means and the second rotational stopping means, and to optimize the rotational blocking while distributing the forces related to the rotational blocking on the contact surface.

[0058] More particularly, in this embodiment, the first rotational stopping means 31 and the second rotational stopping means 12 have a toothed shape.

[0059] According to other embodiments, other shapes could be provided, such as a rectangular shape or a shape with notches of any shape and notches of complementary shape opposite each other.

[0060] As illustrated in figures 3 and 4, in the initial position of the pusher 3 corresponding to an engaged position of the first rotation stop means 31, an upper surface 320 of the secondary portion 32 comes to lock in translation along the radial axis R against an upper wall 210 of the housing 21.

[0061] In other words, the secondary portion comes to rest against an upper wall of the housing when the pusher 3 is in its initial position. This maintains alignment between the end 300 of the main portion 3 and the upper surface of the inlet cone so that, in the initial position, the end 300 of the main portion 30 is flush with the external surface of the inlet cone 9.

[0062] Furthermore, in this embodiment, the rotation-locking device includes a translation stop ring 4 housed at a lower end of the housing 21 so that, in the retracted position of the pusher 3 corresponding to a disengaged position of the first rotation-locking means 31, a lower surface 321 of the secondary portion 32 comes to be blocked in translation along the radial axis R against the translation stop ring 4.

[0063] Thus, in this embodiment, the pusher is allowed to move in translation between a radially high position, corresponding to the initial position, in which an upper surface 320 of the secondary portion 32 comes to be blocked in translation along the radial axis R against an upper wall 210 of the housing 21, and a radially low position, corresponding to the retracted position, in which the lower surface 321 of the secondary portion 32 comes to be blocked in translation along the radial axis R against the translation stop ring 4.

[0064] Furthermore, in this embodiment, the rotation locking device includes a return spring 5 provided between the translation stop ring 4 and the lower surface 321 of the secondary portion 32. This return spring 5 is intended to return the pusher 3 to its initial position when it is translated radially towards the inside of the inlet cone.

[0065] This return spring 5 is here an annular spring so that the return force exerted is homogeneous over the lower surface 321 of the secondary portion.

[0066] According to variations of this embodiment, the locking device could be provided to comprise several springs, for example regularly distributed so as that the sum of the restoring forces exerted is homogeneous over the lower surface of the secondary portion.

[0067] In this embodiment, the rotation-locking device comprises a plurality of pushers 3, each provided with a main portion 30 mounted to slide along a radial axis R orthogonal to the longitudinal axis X in an orifice 20 formed in the downstream ferrule 2, the orifices being regularly distributed angularly on the surface of the downstream ferrule 2.

[0068] According to embodiments, it could for example be provided that the rotation blocking device comprises 3 pushbuttons, each being separated from the adjacent pushbuttons by an angle substantially equal to 120 degrees.

[0069] It could also be envisaged that the rotation-locking device comprises 6 pushbuttons, each being separated from the adjacent pushbuttons by an angle substantially equal to 60 degrees.

[0070] It should be noted that, in this embodiment, and prior to the rotational locking of the upstream cone 1 relative to the downstream ferrule 2, the upstream cone 1 is screwed relative to the downstream ferrule 2.

[0071] For this purpose, the support platform 11 further includes a section 110 having a threaded upper face intended to screw onto a tapped hole formed on a portion 24 of a lower face of the downstream ferrule 2.

[0072] According to different embodiments, this threaded upper face can extend over the entire perimeter of the section, or over one or more parts suitable for coming into contact with one or more threaded portions formed on a portion of a lower face of the downstream ferrule.

[0073] The operation of this rotation-locking device is described in more detail below. When the user presses the push button 3, it is moved in the orifice 20 from the initial position to the retracted position and the first rotation-locking means are moved from the engaged position to the disengaged position, the upstream cone 1 then no longer being blocked from rotation relative to the downstream ferrule 2.

[0074] In an embodiment not shown, disassembly may include a step of inserting a tool onto the end of the pusher so as to exert radial pressure on the pusher. Such radial pressure allows the first rotational locking means to be radially separated, and thus allows, for example, the upstream cone to be unscrewed from the downstream ferrule.

[0075] For mounting the upstream cone on the downstream ferrule, the user can, initially, screw the upstream cone onto the downstream ferrule at the section having a threaded upper face intended to screw onto a tapped hole formed on a portion of an underside face of said downstream ferrule, while maintaining pressure on the pusher so that the upstream cone can be screwed into its final position. Then, by releasing the pressure exerted on the pusher, it returns to its initial position by means of the return spring and the first rotation stop means return to the engaged position in which they are in contact with the second rotation stop means so as to block a rotation of the upstream cone along the longitudinal axis X.

Claims

Claims

1. Inlet cone (9) for an aircraft turbomachine fan mounted to rotate about a longitudinal axis (X), comprising an upstream cone (1) carrying a top (S) and a downstream shroud (2), the upstream cone (1) and the downstream shroud (2) jointly forming the external surface of said inlet cone (9), characterized in that the inlet cone (9) further comprises a rotation locking device comprising a pusher (3) provided with a main portion (30) slidably mounted along a radial axis (R) orthogonal to the longitudinal axis (X) in an orifice (20) formed in said downstream shroud (2), said main portion (30) carrying first rotation stopping means (31) of said upstream cone (1) capable of engaging against second rotation stopping means (12) provided at one end of a support platform (11) of said upstream cone (1),said first rotation stop means (31) being movable between at least: - an engaged position in which said first rotation stop means (31) are in contact with said second rotation stop means (12) so as to block a rotation of said upstream cone (1) along said longitudinal axis (X); - a disengaged position in which said first rotation stop means (31) are radially spaced from said second rotation stop means (12), the passage of said first rotation stop means (31) from the engaged position to the disengaged position being effected by translation of said pusher (3) from an initial position in which one end (300) of said main portion (30) is flush with said external surface of said inlet cone (9) to a retracted position in which said end (300) is pressed into said orifice (20).,

2. Inlet cone (9) according to claim 1, characterized in that said first rotation stop means (31) and said second rotation stop means (12) have a substantially complementary shape.

3. Inlet cone (9) according to claim 2, characterized in that said first rotation stop means (31) and said second rotation stop means (12) have a toothed shape.

4. Inlet cone (9) according to one of claims 1 to 3, characterized in that said pusher (3) further comprises a secondary portion (32) integral with the main portion (30) and extending in a plane orthogonal to said main portion (30), said secondary portion being intended to slide in a housing (21) formed in said downstream ferrule (2) so that, in the initial position of said pusher (3) corresponding to an engaged position of said first rotation stop means (31), an upper surface (320) of said secondary portion (32) is locked in translation along said radial axis (R) against an upper wall (210) of said housing (21).

5. Inlet cone (9) according to claim 4, characterized in that said rotation locking device further comprises a translation stop ring (4) housed at a lower end of said housing (21) so that, in the retracted position of said pusher (3) corresponding to a disengaged position of said first rotation stop means (31), a lower surface (321) of said secondary portion (32) is locked in translation along said radial axis (R) against said translation stop ring (4).

6. Inlet cone (9) according to claim 5, characterized in that said rotation locking device further comprises at least one return spring (5) arranged between said translation stop ring (4) and said lower surface (321) of said secondary portion (32), said at least one return spring (5) being intended to return said pusher (3) to its initial position.

7. Inlet cone (9) according to one of the preceding claims, characterized in that said main portion (30) has a substantially cylindrical shape extending along said radial axis (R), and in that said pusher (3) has indexing means intended to block a rotation of said main portion (30) along said radial axis (R).

8. Inlet cone (9) according to one of the preceding claims, characterized in that it further comprises sealing means provided between said pusher (3) and said orifice (20) and / or between said pusher (3) and said housing (21).

9. Inlet cone (9) according to one of the preceding claims, characterized in that said rotation locking device comprises a plurality of pushers (3), each provided with a main portion (30) slidably mounted along a radial axis (R) orthogonal to the longitudinal axis (X) in an orifice (20) formed in said downstream ferrule (2), said orifices being regularly distributed angularly on the surface of said downstream ferrule (2).

10. Inlet cone (9) according to one of the preceding claims, characterized in that the support platform (11) further comprises a section (110) having a threaded upper face intended to be screwed onto a thread formed on a portion (24) of a lower face of said downstream ferrule (2).

11. Fan for an aircraft turbomachine mounted to rotate about a longitudinal axis (X), characterized in that it comprises an inlet cone according to one of claims 1 to 10.

12. Turbomachine for aircraft characterized in that it comprises a fan according to claim 11.

13. Turbomachine for aircraft according to claim 12, characterized in that it is a turbojet.

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