ARTICULATION DEVICE FOR THE ROTATION OF A PART OF AN AIRCRAFT TURBOMACHINE

Abstract

The invention relates to an articulation device (601) for rotating a component (603) of an aircraft turbomachine. The articulation device (601) comprises a fixed frame (605) having two through holes (607) aligned on the same axis (X), two pivots (609) inserted into the holes (607) and held in said holes (607) by means of fastening means (611) and bushings (613), and a hinge (615) for attachment to the door (603). The hinge (615) is integral with two ball joints (617), mounted respectively on a portion of each pivot (609), so as to establish a ball joint connection between the door (603) and the fixed frame (605) and to allow rotation of the component (603) about the axis (X). (See Fig. 7 for abbreviations.)

Description

Title of the invention: ARTICULATION DEVICE FOR THE ROTATION OF A PART OF A TURBOMACHINE D'AERONEF technical field

[0001] The invention relates to the field of kinematics of parts of an aircraft turbomachine. It relates in particular to an articulation device for the rotation of a part of an aircraft turbomachine. Previous technique

[0002] In an aircraft turbomachine, to regulate the flow rate of the air circulating in a duct and to avoid the pumping phenomenon or to evacuate debris present in said duct, it is known to use variable discharge valves or VBV (from the English "Variable Bleed Valve").

[0003] Such valves can be in the closed position and not cause any change in the circulation of the air flow at the level of the vein in which they are mounted or in the open position in which all or part of the flow is diverted to another vein by passing through the opening.

[0004] Fig. 1, from patent application WO-A1-2020 / 007847, shows an aircraft turbomachine 100 extending longitudinally along an X axis.

[0005] The turbomachine 100 comprises a fan 104, an inner shell 105, and an outer shell 106. The fan 102 is driven in rotation about the X-axis of the turbomachine 100 in order to draw in an airflow which is separated by the inner shell 105 into a first drive airflow for the turbomachine, called the primary flow, and a second thrust airflow, called the secondary flow. The inner shell 105 extends substantially along the X-axis of the turbomachine 100, and the outer shell 106 extends outside the inner shell 105.

[0006] The primary airflow extends internally to the inner ferrule 105 in a primary vein VI while the secondary airflow extends externally to the inner ferrule 105 in a secondary vein V2. The inner ferrule 105 and the outer ferrule 106 delimit the secondary vein V2 for the circulation of the secondary airflow.

[0007] The turbomachine 100 includes a compressor 101 to accelerate the primary flow, a combustion chamber 102 to energize it and a turbine 103 driven by the energized airflow to drive the compressor 101.

[0008] Typically, in an aircraft turbomachine of this type, the compressor 101 includes variable relief valves that are configured to move between a closed position, in which a circulation of airflow from the primary runner VI to secondary vein V2 is prohibited, and an open position in which circulation of an airflow from primary vein VI to secondary vein V2 is permitted.

[0009] Fig. 2 (from patent FR-B1-2982904) shows, in an embodiment according to the prior art, the various parts which enable the movement (also referred to as kinematics), around an axis 201, of variable discharge valves and which can be, for example, integrated into a compressor.

[0010] In this example, a control ring 203 is driven in rotation by hydraulic cylinders 205 and is connected to a gate 207 for each variable relief valve 209 via control rods and connecting rods so as to transmit the force (from the cylinder) which leads to the opening (or closing) of the gate 207.

[0011] In addition, the rotation of each gate 207 of variable discharge valve is made possible by the presence of an articulation device, in which pivots are present, which define the axis of rotation 201.

[0012] Fig. 3 shows, according to different views, an articulation device 301 for the rotation of a door 300 of a variable discharge valve of an aircraft turbomachine according to the prior art.

[0013] In particular, the articulation device 301 includes a fixed frame 303 which has two through holes 305, opposite each other, and aligned on the same axis X (i.e. the axis around which the rotation takes place).

[0014] The articulation device 301 also includes two pivots 307 around which the rotation takes place (since they are positioned on the X axis), which are inserted into the orifices 305, and held in the orifices 305 by means of, firstly, fixing means 309, secondly, rings 311 positioned in openings of the fixed frame 303 around the pivots 307, and thirdly, bushings 313 positioned in the orifices 305, between the fixed frame 303 and the pivots 307.

[0015] In this case, the fixed frame 303 is mounted on an intermediate housing of an aircraft turbomachine (not shown), the pivots 307 are screws, and the fastening means 309 are the screw heads, the screw threads, and complementary threaded nuts. Furthermore, the bushings 311 and the pivots 307 are made of Inconel®, i.e., a metal alloy.

[0016] This type of articulation device implies strict control of the coaxiality of the machining of the orifices 305 (i.e. of the housings of the pivots) at the level of the fixed frame 303. Indeed, given the operation of the pivot connection, a lack of coaxiality of the pivots 307 can lead to a decrease in performance of the articulation device 301 and especially to premature wear of the pivots 307.

[0017] Figure 4 shows another embodiment of a joint device in which the arrangement of the rings 311 has been modified to reduce the problem related to the co- axiality of the pivots. However, even with this type of change, an imprecise coaxiality of the 307 pivots remains. Summary of the invention

[0018] The present invention proposes a solution to these drawbacks.

[0019] Thus, an objective of the invention is to propose an articulation device in which the deterioration of the pivots, and of the articulation in general, linked to the misalignment of the pivots and / or the deformation of the fixed frame is reduced.

[0020] To this end, the invention, according to a first aspect, relates to an articulation device for the rotation of a part of an aircraft turbomachine, said articulation device comprising:

[0021] - a fixed frame comprising two through-holes, opposite each other, and aligned on the same axis;

[0022] - two pivots, inserted into the orifices, and held in said orifices by via fastening means and sockets positioned in said orifices, between the fixed frame and the pivots,

[0023] said articulation device being characterized in that it further comprises two hinges intended to be fixed to the part, each hinge being integral with a ball joint, respectively mounted on a portion of each pivot, so as to establish a ball joint connection between the part and the fixed frame and to allow the rotation of said part around the axis.

[0024] The articulation device according to the invention may comprise one or more of the following features, taken individually or in combination with each other: - the part is a door of a variable discharge valve.

[0025] - each hinge comprises two arms, extending on either side of the area of joint with a ball joint, forming a non-zero angle between them, and at the distal ends of which are located two other orifices intended to receive means of fixing to the part. - at least one arm of the hinge is flexible and capable of deforming in such a way as to allow movement of the part relative to the fixed frame. - the pivots, the fixing means and the sockets are configured so that each ball joint is clamped onto a pivot so that the translation of said ball joint along the direction of said pivot is prevented.

[0026] - when said articulation device is assembled, for each ball joint, a face located at one end of said ball joint along the axis direction, bears against one face of a socket, and a face located at the other end of said ball joint along the axis direction bears against one face of the fastening means, so that Each ball joint is tightened at the aforementioned ends.

[0027] - each pivot is a screw with a smooth shank and the fastening means comprise a head of the screw, a thread of the screw and complementary threaded nut of said thread.

[0028] - the bushings are pressed into the holes of the fixed frame in which they are positioned tiones.

[0029] - the ball joints were made integral with the hinges by crimping said ball joints in the said hinges.

[0030] The invention according to a second aspect also relates to an assembly comprising a gate of a variable discharge valve and an articulation device according to the first aspect.

[0031] The invention according to a third aspect finally relates to an aircraft turbomachine comprising an assembly according to the second aspect. Brief description of the drawings

[0032] The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0033] [Fig.1] is a schematic representation of an embodiment of a turbomachine according to the prior art;

[0034] [Fig.2] is a schematic representation of an embodiment of an assembly comprising a control ring and variable discharge valves according to the prior art;

[0035] [Fig.3] is a set of views, from several angles, of an embodiment of an articulation device according to the prior art;

[0036] [Fig.4] is a cross-sectional view of an embodiment of a joint device according to the prior art;

[0037] [Fig.5] is a perspective view of an embodiment of an articulation device according to the invention;

[0038] [Fig.6] is a cross-sectional view of an embodiment of an articulation device according to the invention;

[0039] [Fig. 7] is a cross-sectional view of an embodiment of an articulation device according to the invention; and,

[0040] [Fig.8] is a cross-sectional view of an embodiment of an articulation device according to the invention. Description of the implementation methods

[0041] With reference to figures 5 to 7, we will now describe an embodiment of an articulation device 601 for the rotation of a part 603 of an aircraft turbomachine according to the invention. Throughout what follows, part 603 is a gate of a variable discharge valve. However, a person skilled in the art will appreciate that the invention applies to any part of an aircraft turbomachine that is required to perform a rotational movement relative to a given axis during its use.

[0042] Such a hinge device is, for example, included in an assembly 600 which also includes the gate 603 of a variable relief valve such as the variable relief valves 209 described with reference to [Fig. 2]. More generally, such a hinge device is intended to be mounted in an aircraft turbomachine such as the aircraft turbomachine 100 described with reference to [Fig. 1].

[0043] The articulation device 601 includes a fixed frame 605 which has two through holes 607, opposite each other and aligned on the same axis X.

[0044] The term "fixed" means that the frame 605 is intended to be mounted on an element, for example on a turbomachine housing, and is not movable relative to that element. This contrasts with the door 603, which is movable relative to that element, particularly due to the articulation device 601 that allows its rotation, so as to be able to move from an open position to a closed position and vice versa.

[0045] In addition, as will be shown in more detail below, the fixed frame 605 has a function of both pivot door and joint door.

[0046] Indeed, the articulation device 601 also includes two pivots 609 (also referred to as axes) which are inserted into the orifices 607 and held in these orifices 607 by means of, on the one hand, fixing means 611 and, on the other hand, bushings 613 positioned in the orifices, between the fixed frame 605 and the pivots 609.

[0047] The pivots 609 thus positioned are therefore also aligned on the X axis around which the rotation of the door 603 can be carried out.

[0048] In the non-limiting example shown, each pivot 609 is a screw with a smooth shank (the smooth part being the part on which the ball joints described later are mounted) and the fastening means 611 include a head 61 la of the screw, a thread 611b of the screw and a threaded nut 611c complementary to said thread 611b.

[0049] In the various embodiments of the invention, the fastening means 611 may or may not be integrated into the pivot 609. These fastening means allow the pivots 609 to remain positioned in the orifices 607 even when they are subjected to strong vibrations and they allow in particular to limit or prevent the exit of the pivots 609 from the orifices 607 by translation along their direction (i.e. the direction of their longitudinal extent).

[0050] The articulation device 601 further includes hinges 615 which are intended to be fixed to the door 603. Each hinge 615 is integral with a ball joint 617, respectively mounted on a portion (for example a smooth portion) of each pivot 609, so as to establish a ball joint connection between the door 603 and the fixed frame 605 and to allow the door 603 to rotate around the X axis.

[0051] The presence of a ball joint, and therefore of a ball joint connection between the door 603 and the fixed frame 605, also allows rotation (or combination of rotations) around all axes of an orthonormal frame which includes the X axis. In the non-limiting example shown, each hinge 615 has two arms 615a and 615b, which extend on either side of a zone 615c of solidarity with a ball joint 617, which form a non-zero angle between them, and at the distal ends of which are located two other orifices 619 intended to receive means of fixing 621 to the door 603.

[0052] In this example, the fastening means 621 are screws which are inserted into complementary holes in the door 603 and which allow each hinge 615 to be tightened, for example via complementary nuts, on said door 603. The door 603 is therefore fixed to the hinge 615 at several distinct points which can be, for example, equidistant from the ball joint.

[0053] Generally speaking, a person skilled in the art will know how to adapt the shape of each hinge to optimize the transmission of force, the rigidity and the simplicity of manufacturing the hinges.

[0054] Furthermore, in a particular embodiment, at least one arm 615a or 615b of each hinge 615 is flexible and capable of deforming so as to allow movement of the door 603 relative to the fixed frame 605. [Fig.8] shows in particular the flexibility zone 901 of an arm 615b which is capable of deforming (i.e., flexing).

[0055] Advantageously, a hinge 615 with such flexibility makes it possible to compensate for the hyperstaticity of the existing connection between the fixed frame 605 and the door 603. In other words, the flexibility of the hinge 615 avoids adding stresses that are not necessary for the proper functioning of the ball joint.

[0056] In a particular embodiment, the pivots 609, the fastening means 611 and the bushings 613 are configured so that each ball joint 617 is clamped onto a pivot 609 (in the longitudinal extension direction of the pivot) so that the translation of the ball joint 617 in the direction of the pivot 609 is prevented.

[0057] In other words, the shape and dimensions of these elements are designed to prevent any play in their assembly. Thus, no play remains in the assembly of the fastening means / ball joint / socket / pivot (when the articulation device is assembled), so that the ball joint 617 cannot slide on the pivot 609. More specifically, with regard to the non-limiting example described, as shown in more detail in [Fig. 6], when the articulation device 601 is assembled, for each ball joint 617, one (flat) face located at one end of the ball joint 617 along the direction of the X-axis bears against one face of a sleeve 613, and another face The plate located at one end of the ball joint 617 along the X-axis bears against one face of the mounting means 611, so that each ball joint 617 is clamped at its ends (along the X-axis). This clamping prevents the ball joint 617 from moving on the pivot 609.

[0058] Furthermore, the bushings 613 can be shrunk into the holes 607 of the fixed frame 605 in which they are positioned. Thus, they cannot slip into the holes once they have been positioned there. Finally, in the particular embodiment described with reference to Figures 5 to 8, the ball joints 617 have been made integral with each hinge 615 by crimping the ball joints 617 into the hinges 615. In particular, the ball joints 617 are assembled to the hinges 615 at the level of the 615c areas of integration in which they are crimped.

[0059] In conclusion, thanks to the invention, as illustrated more specifically in [Fig.7] (via in particular the dotted axes 623), the addition of ball joints at the pivots provides increased freedom of misalignment of the pivots, which allows for a relaxation of manufacturing tolerances on the machining of the holes in which the pivots are positioned.

[0060] This tolerance also allows for a better response to potential deformations of the fixed frame. Since the pivot function (which allows rotation) is ensured by the ball joints themselves, wear on the pivot / bushing assemblies is thus reduced.

Claims

Demands

1. Articulation device (601) for the rotation of a part (603) of an aircraft turbomachine, said articulation device (601) comprising: - a fixed frame (605) having two through orifices (607), opposite each other, and aligned on the same axis (X); - two pivots (609), inserted into the orifices (607), and held in said orifices (607) by means of fixing means (611) and bushings (613) positioned in said orifices (607), between the fixed frame (605) and the pivots (609), said articulation device (601) being characterized in that it further comprises two hinges (615) intended to be fixed to the part (603), each hinge (615) being integral with a ball joint (617), respectively mounted on a portion of each pivot (609), so as to establish a ball joint connection between the part (603) and the fixed frame (605) and to allow the rotation of said part (603) around the axis (X).

2. Articulation device (601) according to claim 1, wherein the part (603) is a gate of a variable discharge valve.

3. Articulation device (601) according to claim 1 or claim 2, wherein each hinge (615) comprises two arms (615a, 615b), extending on either side of the area (615c) of solidarity with a ball joint (617), forming a non-zero angle between them, and at the distal ends of which are located two other orifices (619) intended to receive means for fixing (621) to the part (603).

4. Articulation device (601) according to claim 3, wherein at least one arm (615a, 615b) of each hinge (615) is flexible and capable of deforming so as to allow movement of the part (603) relative to the fixed frame (605).

5. Articulation device (601) according to any one of the preceding claims, wherein the pivots (609), the fastening means (611) and the bushings (613) are configured so that each ball joint (617) is clamped onto a pivot (609) so that the translation of said ball joint (617) in the direction of said pivot (609) is prevented.

6. Articulation device (601) according to claim 5, wherein when said articulation device (601) is assembled, for each ball joint (617), a face located at one end of said ball joint (617) along the direction of the axis (X), is in contact with a face of a sleeve (613), and a face located at another end of said ball joint (617) along the direction of the axis (X) is in contact with a face of the fastening means (611), so that each ball joint (617) is clamped at said ends.

7. Articulation device (601) according to any one of the preceding claims, wherein each pivot (609) is a screw with a smooth shank and the fastening means (611) comprise a head (611a) of the screw, a thread (611b) of the screw and a threaded nut (611c) complementary to said thread (611b).

8. Articulation device (601) according to any one of the preceding claims, wherein the bushings (613) are shrunk into the holes (607) of the fixed frame (605) in which they are positioned.

9. Articulation device (601) according to any one of the preceding claims, wherein the ball joints (617) have been made integral with each hinge (615) by crimping said ball joints (617) into said hinges (615).

10. Assembly (600) comprising a gate (603) of a variable discharge valve and a hinge device (601) according to any one of the preceding claims.

11. Aircraft turbomachine comprising an assembly (600) according to claim 10.

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