DISCHARGE DOOR CONTROL DEVICE FOR AN AIRCRAFT TURBOMACHINE

Abstract

A device (50) for controlling relief gates (52) for an aircraft turbomachine (10), said device (50) comprising: - a series of relief gates (52), and - a control system (54) for the relief gates (52) comprising at least one actuator (56) including a fixed cylinder (58) and a movable piston (60), characterized in that the control system (54) is of the octopus type and comprises a single first part (54a) connected to the movable piston (60) and a second part (54n) divided into several branches (62) each extending between the first part (54a) and the relief gates (52), the number of branches (62) being equal to the number of relief gates (52) and the branches (62) being respectively connected to the relief gates (52). Figure for the abbreviation: Figure 3

Description

Title of the invention: DISCHARGE DOOR CONTROL DEVICE FOR AN AIRCRAFT TURBOMACHINE Technical field of the invention

[0001] The present invention relates to a discharge gate control device for an aircraft turbomachine, as well as a turbomachine comprising such a device. Technical background

[0002] The prior art includes in particular documents FR-A1-3 082 562, FR-Al-3 083 577 and FR-A1-3 119 421.

[0003] An aircraft turbomachine includes a gas generator which conventionally comprises, from upstream to downstream, with reference to the gas flow in the turbomachine, at least one compressor, an annular combustion chamber, and at least one turbine. In the case of a twin-spool turbojet engine, with low-pressure and high-pressure cylinders respectively, the gas generator comprises successively a low-pressure compressor, a high-pressure compressor, the combustion chamber, a high-pressure turbine, and a low-pressure turbine. The gas generator defines a first annular flow path of gas, called the primary flow, which passes through the compressors, the combustion chamber, and the turbines.

[0004] The rotor of the high-pressure compressor is connected to the rotor of the high-pressure turbine by a high-pressure shaft. The rotor of the low-pressure compressor is connected to the rotor of the low-pressure turbine by a low-pressure shaft which passes through the high-pressure shaft and drives a propulsion propeller, generally located upstream of the gas generator.

[0005] When this propeller is enclosed and therefore surrounded by an annular casing, this propeller is called a blower and generates an airflow, called a secondary flow, which flows around the gas generator.

[0006] Discharge gates are generally installed in an annular row at the level of the compressor(s) of the gas generator, and in particular between the low-pressure and high-pressure compressors. Their opening and closing serve to regulate the air leakage rate from the primary flow path to the secondary flow path, depending on the operating conditions of the turbomachine, for example to prevent a pumping phenomenon.

[0007] The discharge gates are distributed around a first axis and each movable by pivoting about a second axis tangent to a circumference centered on the first axis. The discharge gates are controlled by a control system which This allows them to be moved in synchronized pivoting around their second axes. As is known, this control system includes one or more actuators, for example cylinders, comprising a fixed cylinder and a moving piston.

[0008] Prior art control systems are often heavy and bulky due to their complexity. They include, for example, a large number of rigid components that are articulated by complex links.

[0009] More specifically, the technical constraints and problems of known control systems are as follows.

[0010] - The mass of the components between the cylinder and the discharge gates can represent several kilograms. The mass depends primarily on the mounting diameter and the actuation force to be transmitted. The combination of these two parameters results in volumes of material, the portion of which intended for force transmission requires material reserves to ensure sufficient system stiffness, guaranteeing its precision. On current motors, the aforementioned mass can amount to around ten kilograms.

[0011] - The bulkiness of these systems has a significant impact on the constraints installation, as well as the accessibility of components and the design of surrounding rooms.

[0012] - The trade-off between mass and system complexity limits leads to positioning The cylinder is located quite close to the discharge gates, which is restrictive for the installation, the aerodynamic lines of the primary and secondary flows, and the type of cylinder. Furthermore, the use of a fuel-powered hydraulic cylinder necessitates a large fire protection zone, with implications for surrounding components.

[0013] - The lifespan of these systems is linked to the durability of the articulated joints. These Components considered consumables in the assembly necessitate maintenance interventions, sometimes even before they are required. Furthermore, since these connections are the primary site of system damping / accommodation, additional degradation can occur due to behavioral changes by external parties. Consequently, systems reinforced with specific coatings or materials must be designed to withstand, for example, a significant system mass or vibrational coupling phenomena.

[0014] - The current control accuracy is related, in addition to the stiffness of the components, the number of intermediate mechanical links that require internal operating clearances. The cumulative clearance increases as the links wear, thus degrading the system's precision.

[0015] - The complexity of these mechanisms is a direct source of manufacturing costs.

[0016] The present invention proposes a solution to at least some of the problems of the prior art, which is simple, effective and economical. Summary of the invention

[0017] The invention relates to a discharge door control device for an aircraft turbomachine, this device comprising:

[0018] - a series of discharge gates distributed around a first axis and movable each pivoting about a second axis tangent to a circumference centered on the first axis, and

[0019] - a control system for the discharge gates for their syn-pivoting Chronologically defined around their second axes, this control system includes at least one actuator such as a cylinder, comprising for example a fixed cylinder and a movable piston,

[0020] characterized in that the control system is of the octopus type and comprises a single first part connected to the actuator, and in particular to the moving piston, and a second part divided into several branches which each extend between the first part and the discharge gates, the number of branches being equal to the number of discharge gates and the branches being respectively connected to the discharge gates, the control system being configured to transform a translational movement of the actuator into a pivoting movement of the discharge gates.

[0021] The present invention thus proposes to use an octopus-like control system. An octopus comprises a single body connected to several tentacles. In the context of the present invention, the control system comprises a single part forming the octopus body, and several branches forming the octopus tentacles. It is therefore understood that each of the discharge gates is connected to one end of a branch and that the opposite ends of all the branches are connected to the single part that provides the link between these branches and the moving part of the actuator. The moving part of the actuator transmits tensile and pushing forces to the system, which are transmitted to the discharge gates for the purpose of pivoting them and thus opening and closing them.

[0022] The control system configuration eliminates several drawbacks and problems of the prior art. Firstly, the system can be simpler and lighter than those of the prior art. Secondly, it allows the actuator to be located away from the discharge gates, thus avoiding obstruction of the area around the discharge gates by the cylinder. Furthermore, if the actuator is hydraulic and operates using a flammable hydraulic fluid, such as fuel, it would allow the fire zone caused by supplying the cylinder with fuel to be moved away from the discharge gates.

[0023] The system may comprise one or more cylinders, namely a single cylinder which is connected by the octopus to all the discharge gates, or two or more cylinders which are each connected by an octopus-like coupling to a section of the discharge gates. It is therefore understood that the number of octopus-like couplings depends on the number of cylinders and, in particular, is equal to the number of cylinders.

[0024] The device according to the invention may comprise one or more of the following features, taken individually or in combination with each other: - the first part is connected to the branches by a sliding multiplexing device; - the first part includes a tubular sheath inside which is able to slide an elongated blade, one end of which is connected to the actuator, and in particular to the moving piston, and the other opposite end of which is connected to the branches;

[0025] — the cable is rigid, semi-rigid or flexible; - the second end of the blade is connected to the multiplexing unit which is connected to each of the branches; - the first end of the blade is connected to the actuator by being engaged in a slot of the actuator, and in particular of the piston, and by being immobilized in this slot by cooperation of shapes and screwing a nut around this end; - each of the branches includes a straight portion located on the side of the first part, and a non-straight portion located on the side of the discharge gates; - each branch comprises at least two straight portions located on the side of the first and second parts, and an intermediate straight and / or non-straight portion, - the straight portion of each branch is rigid or flexible, and the non-straight portion of each branch is flexible;

[0026] — the straight portions of the branches are joined and solid to one another, and the non-straight portions of the branches are independent of each other; - each of the branches includes a cable, preferably flexible, which includes a tubular sheath inside which an elongated blade is able to slide; - the blade of each of the branches has an end which is connected to the multiplexing unit by a ball joint; - the blade of each of the branches has an end which is connected to the multiplexing unit by a ball joint; - the blade of each of the branches has an end which is connected to the corresponding discharge gate by a chain and / or a connecting rod;

[0027] — the chain has one end connected to the end of the blade and one end opposite connected to one end of the connecting rod, the opposite end of which is connected to the discharge gate; the chain is useful in case of a requirement for angled path, in particular in the case of a radius of curvature incompatible with the bending capacity of the blade; - the chain is mobile in translation, for example by rolling, inside a sheath, preferably bent; the chain is preferably guided by rolling using rollers for example in the sleeve; it is then a translation by rolling and not by friction; the chain is articulated; - at least one end of the connecting rod includes a ball joint, and / or at least one end of the chain includes a ball joint; - the device further includes an annular housing which extends around the first axis, as well as supports for the control system which are carried by the housing; - the supports include several arms which extend, for example axially or radially, outwards from the housing and which include at their free ends opposite the housing fastening elements, such as mounting collars;

[0028] — the actuator is electric or hydraulic.

[0029] The present invention also relates to an aircraft turbomachine, comprising at least one device as described above. Brief description of the figures

[0030] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which:

[0031] [Fig-1] [Fig.1] is a schematic half-view in axial section of a part of a aircraft turbomachine,

[0032] [Fig.2] [Fig.2] is a schematic perspective view of a discharge gate control device according to the prior art,

[0033] [Fig.3] [Fig.3] is a very schematic view of a discharge gate control device according to the invention,

[0034] [Fig.4] [Fig.4] is a schematic perspective view of an embodiment of a discharge gate control device according to the invention,

[0035] [Fig.5] [Fig.5] is a schematic perspective view of a sliding blade cable of the control system according to the invention,

[0036] [Fig.6] [Fig.6] is a schematic cross-sectional view of the sliding blade cable of the [Fig.5]

[0037] [Fig.7] [Fig.7] is a schematic perspective view of the cylinder and the linkage between a first part of the control system and the cylinder,

[0038] [Fig.8] [Fig.8] is a schematic perspective and larger scale view of part of the cylinder of [Fig.7],

[0039] [Fig.9] [Fig.9] is a schematic perspective view of the connection between the first part of the control system and the cylinder of the [Fig.7],

[0040] [Fig. 10] [Fig. 10] is a schematic view of a variant of the connection between the first part of the control system and the cylinder,

[0041] [Fig. 11] [Fig. 11] is a very schematic view of the cables of a second part of the control system according to the invention,

[0042] [Fig. 12a-12b] Figures 12a and 12b are schematic perspective views of the connection between a cable end and a discharge gate of the control system according to the invention,

[0043] [Fig. 13a-13b] Figures 13a and 13b are schematic perspective views of a discharge gate and illustrate two extreme positions of this discharge gate,

[0044] [Fig. 14a-14b] Figures 14a and 14b are schematic perspective views of a another discharge gate and illustrate two extreme positions of this discharge gate,

[0045] [Fig. 15] the [Fig. 15] is a schematic perspective and larger scale view of the connection at one end of the cable of the second part of the control system according to the invention Detailed description of the invention

[0046] Fig. 1 shows a turbomachine 10 for an aircraft, this turbomachine 10 being here a twin-spool turbojet.

[0047] Axis A designates the longitudinal axis of the turbomachine.

[0048] The turbomachine 10 comprises a gas generator 12 which includes, from upstream to downstream with reference to the flow of gases along axis A, a low pressure or LP compressor 14 or, a high pressure or HP compressor 16, an annular combustion chamber, a high pressure or HP turbine and a low pressure LP turbine.

[0049] Although not visible in [Fig.1], the rotor of the HP compressor 16 is connected to the rotor of the HP turbine by a high-pressure shaft, and the rotor of the LP compressor 14 is connected to the rotor of the LP turbine by a low-pressure shaft which passes through the high-pressure shaft and drives a propulsion propeller, called a blower 23, located upstream of the gas generator 12 and which is surrounded by an annular casing called a blower casing 24.

[0050] The blower housing 24 is connected to the gas generator 12 by an intermediate housing 26 which includes a central hub 28 and a series of radial arms 30 connecting the hub 28 to the blower housing 24.

[0051] The gas generator 12 defines a main annular flow channel V1 of a first air flow, called primary flow Fl. The gas generator 12 is surrounded by a secondary annular flow channel V2 of a second air flow, called secondary flow F2.

[0052] The airflow F entering the blower 23 splits into a portion forming the primary flow FL. The air in this primary flow FL is compressed in the compressors BP 14 and HP 16, then mixed with fuel and burned in the combustion chamber. The combustion gases of the primary flow are then expanded in the turbines HP and BP and finally flow through an exhaust nozzle.

[0053] The other part of the airflow entering the blower 23 forms the secondary flow F2 and is intended to be mixed with the primary flow Fl downstream of the nozzle.

[0054] A control device to which the invention relates is for example installed between the BP 14 and HP 16 compressors, in the ZI zone delimited by a rectangle in dotted lines.

[0055] Fig. 2 illustrates a control device 30 of the prior art, as described in document FR-A1-3 082 562.

[0056] This device 30 comprises:

[0057] - a series of discharge gates 32 distributed around a first axis, which is the axis A, and each movable in pivoting with respect to a second axis B tangent to a circumference centered on axis A, and

[0058] - a control system 34 for the discharge gates 32 of the control device 30 in view of their synchronized pivoting around the axes B.

[0059] In the case shown, the control system 34 includes at least one cylinder 36 and a control ring 38 centered on the axis A. The cylinder 36 transmits a movement to the control ring 38, and the control ring 38 is connected to each of the doors by linkages 40 which allow the doors 30 to pivot when the ring 38 moves.

[0060] The control devices of the prior art have disadvantages described above and the present invention proposes a new design of control device, one embodiment of which is illustrated schematically in [Fig.3].

[0061] The control device 50 according to the invention comprises:

[0062] - a series of discharge gates 52 distributed around a first axis A and movable each pivoting about a second axis B tangent to a circumference centered on the first axis A, and

[0063] - a control system 54 for the discharge gates 52 for pivoting them synchronized around the second axes B, this control system comprising at least an actuator such as a cylinder 56, comprising a fixed cylinder 58 and an actuator, such as a movable piston 60.

[0064] The particularity of the control device 50 is that its control system 54 is of the octopus type.

[0065] This control system 54 comprises a single first part 54a connected to the movable piston 60 and a second part 54b divided into several branches 62 which each extend between the first part 54a and the discharge gates 52.

[0066] The number of branches 62 is equal to the number of discharge gates 52 and the branches 62 are respectively connected to the discharge gates 52.

[0067] The control system 54 is configured to transform a translational or rotational movement of the mobile piston 60 into a pivoting movement of the discharge gates 52.

[0068] Figure 3 shows several features of the control device 50 according to the invention, some of which are optional. Some of these features will be described in more detail below with reference to Figures 4 and following.

[0069] First, [Fig. 3] shows an example of a configuration with a single cylinder 56 and Four doors 52, but it is understood that the cylinder 56 can be connected to any number of doors 52, and for example to all the discharge doors 52. The number of cylinders 56 is also not limited. The device 50 could, for example, include two cylinders 56, each connected to half of the doors 52.

[0070] Fig. 4, for example, shows the case where a cylinder 56 is connected to three doors 52.

[0071] The cylinder or each cylinder 56 comprises a fixed cylinder 58 and a movable piston 60. The cylinder 58 is preferably fixed to a housing 64 of the turbomachine, and in particular to the outer periphery of this housing 64 in the case where this housing internally delimits the primary flow channel (see [Fig. 1]). The piston 60 is movable in translation relative to the cylinder 58 and is therefore movable from a retracted position within the cylinder 58 to an extended or deployed position.

[0072] The discharge gates 52 are hinged on the casing 64 to be movable by pivoting relative to the axes B.

[0073] As can be seen in [Fig.3], the housing 64 can include several supports 96 for the control system 54. These supports 96 include, for example, several arms 66 extending outwards from the housing 64 and including at their free ends opposite the housing 64 elements 68 for fixing the control system 54, such as mounting collars.

[0074] Advantageously, the cylinder 56 and the multiplexing element 70 can be fixed on the same frame of the housing 64 in order to obtain the most compact assembly possible.

[0075] Figure 3 shows that the first part 54a of the control system 54 can be connected to branches 62 by a sliding multiplexing device 70.

[0076] The first part 54a preferably comprises a cable 72, for example flexible, which includes a tubular sheath 74 inside which is able to slide an elongated blade 76, a first end 76a of which is connected to the movable piston 60, and a second opposite end 76b of which is connected to the branches 62, in particular by the multiplexing member 70.

[0077] Figures 5 and 6 show an example of a cable 72 that can be used within the framework of the present invention. The blade 76 is guided in translation along and inside the sheath 74 by longitudinal ball bearings 78 or the like.

[0078] The sleeve 74 can be semi-rigid (i.e., partly rigid and partly flexible along its length). The sleeve 74 can be made by braiding wires, for example, like a sock. The rolling elements of the bearings 78 can be balls, for example, made of ceramic. The blade 76 can be made of ductile stainless steel to make it fusible under extreme loads, with a self-lubricating coating to ensure smooth sliding.

[0079] The operation of such a cable 72 is similar to that of a jack. By analogy with the cylinder of a jack, the sheath 74 of the cable 72 is fixed and by analogy with the piston of the jack, the blade 76 slides inside the sheath 74 and can transmit a pulling or pushing force.

[0080] Referring again to [Fig. 3], it can be seen that the sheath 74 of the cable 72 is supported by the housing 64 and can, in particular, be held by the aforementioned fastening elements 68. The blade 76 has its first end 76a connected to the piston 60 of the cylinder 56, and its opposite second end 76b connected to the multiplexing element 70. The extension of the piston 60 of the cylinder 56 causes the blade 76 to move in its sheath 74 on the side opposite the cylinder 56, and the retraction of the piston 60 into the cylinder 58 of the cylinder 56 causes the blade 76 to move in its sheath towards the cylinder 56. The multiplexing element 70 transmits its movements to each of the branches 62 in a synchronized and homogeneous manner.

[0081] Figures 7 to 10 show examples of connecting the piston 60 of the cylinder 56 to the first part 54a and in particular to the blade 76.

[0082] Figures 8 and 9 show, for example, that the end 76a of the blade 76 can be engaged in a slot 78 of the piston 60 and held in place in this slot 78 by screwing a nut 80 around this end 76a. The end 76a of the blade 76 may include recessed or protruding elements 82 which cooperate by engaging with complementary protruding or recessed elements of the slot 78, in order to better secure the blade 76 and the piston 60. The nut 80 may have slots / notches to ensure anti-rotation by means of washers with folded tabs in cooperation with the notches of the nut 80.

[0083] Figure 10 shows a variant in which the connection of the piston 60 of the cylinder 56 to the blade 76 is spherical. The end 76a of the blade 76 is engaged in a slot of a sphere 84 which is spherically mounted in a housing of the piston 60.

[0084] The blade 76 must be able to rotate freely on its axis. The ball joint of [Fig. 10] is therefore advantageous. This assembly will preferably allow a slight play in the mounting so as not to lock the sphere 84 vis-à-vis its counterpart.

[0085] Other assemblies of the cylinder 60 to the blade 72 are possible such as crimping or riveting if the system configuration allows it.

[0086] Other ball joint solutions can be considered, such as the use of a ball joint crimped with an inner ring adapted to receive the blade of the flexible control or to accommodate the piston of the cylinder.

[0087] The special feature of the control cable 72 is that it is capable of transmitting forces resulting from the octopus in both directions (push / pull). It will therefore generally have a diameter greater than the individual branches composing the octopus.

[0088] As mentioned above, the second part 54b of the system 54 comprises a multitude of branches 62.

[0089] As shown in Figures 3 and 11, each of these branches 62 comprises a straight portion 62a located on the side of the first part 54a, and a non-straight portion 62b located on the side of the discharge gates 52.

[0090] The straight portion 62a of each branch 62 can be rigid or flexible, and the non-straight portion 62b of each branch 62 can be flexible. In other words, the rigidity of each branch 62 can vary along its length.

[0091] The straight portions 62a of the arms 62 are preferably joined and secured to one another, for example by means of Colson®-type fasteners. The non-straight portions 62b of the arms 62 may be independent of one another to facilitate their connection to the doors 52.

[0092] Each of the branches 62 may include a cable 72', preferably flexible, which includes a tubular sheath 74' inside which an elongated blade 76' is able to slide. It is therefore understood that each of the branches 62 may have a configuration similar to that of the first part 54a of the system and illustrated in Figures 5 and 6.

[0093] A first end 76a' of the blade 76' of each branch 62 is connected

[0094] to the multiplexing unit 70, preferably by a ball joint 85.

[0095] A second opposite end 76b' of the blade 76' of each branch 62 is connected to the corresponding discharge gate 52.

[0096] The multiplexing unit 70, shown schematically in [Fig. 3], comprises, for example, a plate 86 which is connected to the end 76b of the blade 76 of the first part 54a and to the ends 76a' of the blades 76' of the branches 62. The plate 86 is guided in translation by one or more guides 88 which are carried by the housing 64.

[0097] Figures 12a and 12b show an example of a connection between a branch 62 and a discharge gate 52.

[0098] The blade 76' of each of the branches 62 has its end 76b' which is connected to the corresponding discharge gate 52 by a chain 90 and a connecting rod 92.

[0099] As its name suggests, the 90 chain is a small chain composed of links articulated to each other and having in appearance a shape similar to a part of a bicycle chain.

[0100] The chain 90 has an end 90a connected to the end 76b of the blade 76 and an opposite end 90b connected to an end 92a of the connecting rod 92, an opposite end 92b of which is connected to the discharge gate 52.

[0101] The chain 90 is movable in translation inside a sheath 94.

[0102] In the example shown in figures 12a-12b and 13a-13b, the sheath 94 is bent. The elbow can form an angle greater than or equal to 90° and less than 180°.

[0103] In the variant of figures 14a-14b, the sheath is almost straight.

[0104] The chain 90 may include spherical rolling rollers or fixed sliding rollers facilitating its movement in the sheath 94.

[0105] At least one of the ends 92a, 92b of the connecting rod 92 may include a ball joint. At least one of the ends 90a, 90b of the chain 90 may include a ball joint.

[0106] Figures 13a to 14b further show that the control system includes a structural fixing positioned directly upstream of the door 52 to be actuated. The fixing here includes a support fitting 96 secured to the aforementioned housing 64 preferably by bolted connections.

[0107] The fitting 96 can accommodate the aforementioned sheath 94 and / or directly the end of the sleeve 74'.

[0108] The fitting 96 is preferably cantilevered and fixed by at least two screws 98. It will be aligned with the direction of the piston 60, for example. Other fixing points can be added to increase the rigidity of the support (fixing to an additional flange if necessary, for example) or the use of specific materials (forged or composite, for example).

[0109] The fitting 96 can also support and guide the branches 62 traveling towards the other doors 52, for example by means of a cylindrical cutout intended to receive or retain the branches.

[0110] Figure 15 shows an example of connecting the end 76b' of the blade 76' of each arm 62 to the end of the corresponding chain 90. The end 76b' of the blade 76' can be engaged in a slot 78' of the end 90a of the chain 90 and secured in this slot 78' by screwing a nut 80' around this end 76b'. The end 76b' of the blade 76' may include recessed or projecting elements 82' which cooperate by engagement with complementary projecting or recessed elements of the slot 78', in order to better secure the blade 76' and the chain 90 as mentioned above with reference to [Fig. 9]. The nut 80' may have slots / notches to ensure anti-rotation by means of washers with folded tabs in cooperation with the notches of the nut 80'.

[0111] The control device 50 according to the invention is particularly suitable for transmitting equivalent forces in both directions (push and pull). Blade technology is a preferred embodiment of the octopus, but other configurations are possible. This octopus could be a single, inseparable piece to facilitate assembly.

[0112] The present invention offers several advantages, including:

[0113] This architecture makes it possible to do away with a zone dedicated to ring 38 of the previous technique ([Fig.2]) over 360°. The routing of flexible commands can take place in unused or non-dedicated volumes.

[0114] The jack can be positioned / oriented / fixed in the most available, most accessible volumes and the most favorable positions for its support.

[0115] The benefit may also be to reduce the number of fire zones or to redraw their outlines.

[0116] An advantage of installing the cylinder in colder areas opens up the possibilities of using EHA (electro-hydraulic actuator) or electric type actuators.

[0117] The service life of flexible blade or link drives is longer than that of dry bearing mechanisms with friction. The product specification will be for the life of the turbomachine

[0118] Overall accuracy is improved by reducing the number of intermediate bearings (and therefore the internal clearances of each of these links) between the cylinder and each end gate.

[0119] Specific precision is improved, a blade control having a precision on the order of 1%.

[0120] This can result in either improving the accuracy of opening the doors, or accepting less precise actuators and therefore simpler, less expensive, lighter technologies.

[0121] It is estimated that the overall cost of the function is reduced thanks to the opening of collateral opportunities (simplification of the casing, reduction of the number of parts in the kinematics, elimination of fire constraints on certain parts, use of electric actuators...).

Claims

Demands

1. A device (50) for controlling discharge gates (52) for an aircraft turbomachine (10), said device (50) comprising: - a series of discharge gates (52) distributed around a first axis (A) and each movable by pivoting about a second axis (B) tangent to a circumference centered on the first axis (A), and - a control system (54) for the discharge gates (52) for their synchronized pivoting about their second axes (B), this control system (54) comprising at least one actuator such as a cylinder (56), comprising, for example, a fixed cylinder (58) and a movable piston (60), characterized in that the control system (54) is of the octopus type and comprises a single first part (54a) connected to the actuator (56), and in particular to the movable piston (60), and a second part (54b) divided into several branches (62) which each extend between the first part (54a) and the discharge gates (52),the number of branches (62) being equal to the number of discharge gates (52) and the branches (62) being respectively connected to the discharge gates (52), the control system (54) being configured to transform a translational movement of the actuator, and in particular of the movable piston (60), into a pivoting movement of the discharge gates (52).

2. Device (50) according to claim 1, wherein the first part (54a) is connected to the branches (62) by a sliding multiplexing element (70).

3. Device (50) according to claim 1 or 2, wherein the first part (54a) comprises a cable (72) which includes a tubular sheath (74) inside which is able to slide an elongated blade (76) having a first end (76a) connected to the actuator (56), and in particular to the movable piston (60), and having a second opposite end (76b) connected to the arms (62).

4. Device (50) according to all claims 2 and 3, wherein the second end (76b) of the blade (76) is connected to the multiplexing member (70) which is connected to each of the branches (62).

5. Device (50) of claim 3 or 4, wherein the first end (76a) of the blade (76) is connected to the actuator (56) by being engaged in a slot (78) of the actuator (56), and in particular of the piston (60), and in being immobilized in this slot (58) by cooperation of forms and screwing of a nut (80) around this end (76a).

6. Device (50) according to any one of the preceding claims, wherein each of the branches (62) comprises a straight portion (62a) located on the side of the first part (54a), and a non-straight portion (62b) located on the side of the discharge gates (52), or each of the branches (62) comprises at least two straight portions located on the side of the first and second parts (54a-54b) and an intermediate straight and / or non-straight portion.

7. Device (50) according to claim 6, wherein the straight portion (62a) of each arm (62) is rigid or flexible, and the non-straight portion (62b) of each arm (62) is flexible.

8. Device (50) according to any one of the preceding claims, in which each of the arms (62) comprises a cable (72'), preferably flexible, which includes a tubular sheath (74') inside which is able to slide an elongated blade (76').

9. Device (50) according to claim 8, depending on claim 2 or 4, wherein the blade (76') of each of the branches (62) has an end (76a') which is connected to the multiplexing member (70) by a ball joint (85).

10. Device (50) according to claim 8 or 9, wherein the blade (76') of each of the branches (62) has an end which is connected to the corresponding discharge gate (52) by a ball joint.

11. Device (50) according to any one of claims 8 to 10, wherein the blade (76') of each of the branches (62) has an end which is connected to the corresponding discharge gate (52) by a chain (90) and / or a connecting rod (92).

12. Device (50) according to claim 11, wherein the chain (90) is movable in translation, for example by rolling, inside a sheath (94), preferably bent.

13. Device (50) according to claim 11 or 12, wherein at least one of the ends (92a, 92b) of the connecting rod (92) comprises a ball joint, and / or at least one of the ends (90a, 90b) of the chain (90) comprises a ball joint.

14. Device (50) according to any one of the preceding claims, wherein it further comprises an annular housing (64) which extends around the first axis (A), and supports (96) for the control system (54) which are carried by the housing (64).

15. Device (50) according to the preceding claim, wherein the supports (96) comprise several arms (66) extending outwards from the housing (64) and comprising at their free ends opposite the housing fastening elements (68), such as mounting collars.

16. Turbomachine (10) for an aircraft, comprising at least one device (50) according to any one of the preceding claims.

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