AIRCRAFT PROPULSION SYSTEM WITH GONDOLA WITH IMPROVED JOINT SYSTEM

Description

TECHNICAL FIELD

[0001] The present invention relates to an aircraft propulsion system comprising a chassis, a nacelle with two fan cowls, and, for each cowl, an articulation system mounted on the chassis for articulating the fan cowl. The invention also relates to an aircraft comprising such a propulsion system. PREVIOUS STATE OF THE ART

[0002] An aircraft consists of a fuselage with a wing attached to each side. At least one propulsion system, such as a turbofan engine, is suspended beneath each wing. Each propulsion system comprises a frame, a core that constitutes the engine, and a nacelle that surrounds the core, where the core and nacelle are attached to the frame.

[0003] The propulsion system is attached under the wing via a mast which is fixed between the wing structure and the chassis.

[0004] The nacelle includes, among other things, cowlings mounted on the chassis. In the case of a turbofan engine, the nacelle comprises, from front to rear, an air intake cowling, two fan cowlings, and rear cowlings. The air intake cowling defines the nacelle's inlet through which the air that feeds the core is introduced. The fan cowlings surround a fan that draws air from the nacelle inlet and directs it to the core. The rear cowlings cover the rear of the core up to the exhaust nozzle.

[0005] The two fan cowls are hinged to the chassis via hinges whose axes are generally parallel to the longitudinal axis of the propulsion system. At the top of the nacelle, the two fan cowls can be joined together or separated by a fixed cowl.

[0006] Although such an arrangement is satisfactory, interactions can sometimes occur between the two blower hoods or between a blower hood and the fixed hood when opening or closing a blower hood. To limit these interactions, it is known to space the hoods further apart to allow for a significant functional gap between them.

[0007] It is therefore necessary to find an arrangement that prevents, among other things, these interactions, limits the play between the different cowlings, and thus reduces parasitic drag. Document DE 687 496 C describes a drum-shaped aircraft engine cowling made of hinged sections connected on one side by a double hinge and on the other by a clamping closure. STATEMENT OF THE INVENTION

[0008] An object of the present invention is to provide an aircraft propulsion system comprising a chassis, a nacelle with two fan cowls and for each, a particular articulation system mounted on the chassis to articulate the fan cowl.

[0009] To this end, a propulsion system for an aircraft is proposed, said propulsion system comprising: a chassis, a nacelle comprising two blower hoods, for each blower hood, at least one articulation system fixed between the chassis and said blower hood, so as to move said blower hood between a closed position and an open position and vice versa, and for each blower hood, a locking means arranged to alternately take a locked position in which it ensures the locking of said blower hood on the chassis in the closed position and an unlocked position in which it does not ensure the locking of said blower hood on the chassis, where each joint system comprises: a shaft comprising a central cylinder with an axis and at least one lateral cylinder each with an axis, wherein the central cylinder is mounted movably for rotation on the frame about its axis, wherein said at least one lateral cylinder is mounted movably for rotation on the blower hood about its axis, and wherein the axes of said at least one lateral cylinder are coaxial and parallel but distinct from the axis of the central cylinder, locking means arranged to limit the rotation of the central cylinder relative to the frame between a first position corresponding to the closed position of the blower hood and a second position corresponding to an intermediate position of the blower hood in which the blower hood is offset laterally from the side corresponding to said blower hood,and stopping means arranged to permit rotation of the blower hood relative to said at least one lateral cylinder between a first position corresponding to the intermediate position of the blower hood and a second position corresponding to the open position of the blower hood, and to prevent rotation of the blower hood beyond the intermediate position from the open position, wherein the locking means consist of a first pallet fixed to the shaft and two first pads fixed to the frame, wherein the first two pads are arranged on either side of the first pallet, wherein one of the first pads is arranged so that the first pallet abuts against it in the closed position of the blower hood, and wherein the other of the first pads is arranged so that the first pallet abuts against it in the intermediate position of the blower hood.

[0010] With such an arrangement, the fan cowl moves laterally from the beginning of its opening, which allows the fan cowl to be moved away from the neighboring cowl, limiting the risks of interactions and reducing parasitic drag.

[0011] Advantageously, the stopping means consist of a second pallet attached to the shaft and a second block attached to the blower hood, and the second block is arranged so that the second pallet is butted against it in the intermediate position of the blower hood.

[0012] The invention also proposes an aircraft comprising at least one propulsion system according to one of the preceding variants. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The features of the invention mentioned above, as well as others, will become clearer upon reading the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among which: Fig. 1 is a side view of an aircraft according to the invention, Fig. 2 is a perspective view of a propulsion system according to the invention, Fig. 3 is a perspective view of an articulation system according to the invention, Fig. 4 is a perspective view of a tree implemented in the articulation system according to the invention, Fig. 5 is a top view of the articulation system according to the invention, Fig. 6 is a view of the articulation system of the Fig. 5 in cross-section along line VI-VI in the closed position, Fig. 7 is a side view of the articulation system of the Fig. 5 in the closed position, Fig. 8 is a view of the articulation system of the Fig. 5 in cross-section along line VI-VI in offset position, Fig. 9 is a side view of the articulation system of the Fig. 5 in a staggered position, and Fig. 10 is a side view of the articulation system of the Fig. 5 in the open position. DETAILED PRESENTATION OF EMBODIMENT METHODS

[0014] In the following description, terms relating to a position are taken with reference to an aircraft in a forward position as depicted on the Fig. 1 .

[0015] There Fig. 1 shows an aircraft 100 which has a fuselage 102 on each side of which is fixed a wing 104 which carries at least one propulsion system 106 such as a turbofan engine which is fixed under the wing 104 by means of a mast 108.

[0016] There Fig. 2 shows the propulsion system 106 which has a nacelle 202 and a core constituting the engine 204 and housed inside the nacelle 202. The propulsion system 106 also includes a chassis (402, Fig. 3 ) to which are attached, among other things, the engine 204 and the nacelle 202. The engine 204 is represented here by the ejection nozzle.

[0017] In the following description, and by convention, X is called the longitudinal axis of the nacelle 202 which corresponds to the longitudinal axis of the propulsion system 106 and which is parallel to the longitudinal axis of the aircraft 100 oriented here positively in the direction of advancement of the aircraft 100, Y is called the horizontal transverse axis when the aircraft 100 is on the ground, and Z the vertical axis when the aircraft 100 is on the ground, these three directions X, Y and Z being orthogonal to each other.

[0018] Arrow 107 represents the forward direction of aircraft 100 when the propulsion systems 106 are in operation. The nacelle 202 also has a median plane XZ which is vertical and passes through the longitudinal axis X.

[0019] The nacelle 202 comprises, from front to rear, an air intake cowl 206 surrounding the air intake 207, on either side of the median plane XZ, two fan cowls 208, and behind the fan cowls 208, rear cowls 210 which may be the cowls for the thrust reversers of the propulsion system 106. The air intake cowls 206 and the rear cowls 210 are attached to the chassis 402 by any suitable fastening means known to those skilled in the art. In the embodiment of the invention presented in the Fig. 2 , the two fan hoods 208 are, in the upper part of the nacelle 202, separated from each other by an upper hood 211 which is also fixed to the chassis 402. According to another embodiment not shown, of the invention, the two fan hoods 208 are adjacent in the upper part of the nacelle 202.

[0020] The fan cowls 208 surround a fan 212 which is located across the air inlet 207 of the nacelle 202 and which draws air from the air inlet 207 to send it to the engine 204.

[0021] Each fan cowl 208 is hinged to the frame 402 between a closed position, in which it is tight around the engine 204, and an open position, in which it is away from the engine 204, and vice versa. The open position allows access to the inside of the nacelle 202.

[0022] For each fan cowl 208, the drive system 106 also includes a locking mechanism arranged to alternately assume a locked position, in which it secures the fan cowl 208 to the chassis 402 in the closed position, and an unlocked position, in which it does not secure the fan cowl 208 to the chassis 402, and the fan cowl 208 is then free to move. The transition from the locked to the unlocked position and vice versa is carried out, for example, by a technician from outside the nacelle 202. The locking mechanism may be in the form of a lock or any other form known to those skilled in the art.

[0023] As shown by Fig. 3 , for each fan hood 208, the propulsion system 106 includes at least one articulation system 300 fixed between the chassis 402 and said fan hood 208, so as to move said fan hood 208 between the closed position and the open position and vice versa.

[0024] In order to ensure good stability of the blower hood 208, there are preferably two articulation systems 300 per blower hood 208, one of which is arranged at the level of a front part of the blower hood 208 and another of which is arranged at the level of a rear part of the blower hood 208 along the longitudinal axis X.

[0025] Each blower hood 208 extends angularly through approximately 180° around the longitudinal axis X, with one upper end at 12 o'clock and one lower end at 6 o'clock. This angular extent, as well as the position of the upper end, varies depending on whether or not there is an upper hood 211.

[0026] The articulation systems 300 of each blower hood 208 are arranged near the upper end at 12 o'clock so as to move into the open position by lifting the blower hood 208 and the locking means is then arranged at 6 o'clock.

[0027] The description of the 300 articulation systems is now made on a single 300 articulation system, but each 300 articulation system of the same 208 blower hood are preferably identical.

[0028] The articulation system 300 includes a shaft 302, one embodiment of which is shown in the Fig. 4 .

[0029] The shaft 302 includes a central cylinder 302a and at least one lateral cylinder 302b-c.

[0030] For balancing reasons, there are two lateral cylinders 302b-c arranged on either side of the central cylinder 302a.

[0031] The rest of the description is based more particularly on the case where there are two 302b-c side cylinders, but it also applies to the case where there is only one 302b-c side cylinder.

[0032] The side cylinders 302b-c are coaxial with each other and the central cylinder 302a is offset from the side cylinders 302b-c, that is to say that the axes 12b-c of the side cylinders 302b-c are coincident and the axis 12a of the central cylinder 302a and the axes 12b-c of the side cylinders 302b-c are parallel but distinct.

[0033] The three cylinders 302a-c are joined together, here by means of two plates 304a-b. Thus, the central cylinder 302a and a first lateral cylinder 302b are joined together and here on either side of a first plate 304a and the central cylinder 302a and a second lateral cylinder 302c are joined together and here on either side of a second plate 304b.

[0034] The axis 12a-c of each cylinder 302a-c is parallel to the longitudinal axis X.

[0035] The central cylinder 302a is mounted to rotate freely on the chassis 402 around its axis 12a. In the embodiment of the invention presented in the Fig. 3 , the central cylinder 302a is mounted in a through bore of the chassis 402.

[0036] Each side cylinder 302b-c is mounted movably in rotation on the associated blower hood 208 around its axis 12b-c, here by means of a fitting 208a integral with the blower hood 208 and having, for each side cylinder 302b-c, a through bore in which said side cylinder 302b-c is mounted.

[0037] In the closed position, the central cylinder 302a is above the lateral cylinders 302b-c, but a different arrangement with a vertical offset, for example, or even reversed positions are also possible.

[0038] There Fig. 5 shows the articulation system 300 in top view with the two lateral cylinders 302b-c on either side of the central cylinder 302a.

[0039] The articulation system 300 includes locking means 306 which are arranged to limit the rotation of the central cylinder 302a relative to the chassis 402 between a first position corresponding to the closed position of the blower hood 208 and a second position corresponding to an intermediate position of the blower hood 208 between the closed position and the open position of said blower hood 208 in which the blower hood 208 is laterally offset from the side corresponding to said blower hood 208.

[0040] In other words, the blower cowling 208 which is on the starboard, respectively port, is laterally shifted outwards, i.e. to starboard, respectively port, to reach its intermediate position by rotating the central cylinder 302a from its first position to its second position.

[0041] The articulation system 300 includes stop means 308 which are arranged to permit the rotation of the blower hood 208 relative to each side cylinder 302b-c between a first position corresponding to the intermediate position of the blower hood 208 and a second position corresponding to the open position of the blower hood 208 and to prevent the rotation of the blower hood 208 beyond the intermediate position from the open position.

[0042] The principle for opening the fan cowl 208 is as follows: from the closed position, the fan cowl 208 is moved laterally to starboard for the starboard fan cowl 208, and to port for the port fan cowl 208, to reach the intermediate position. This lateral movement corresponds to a rotation around the central cylinder 302a. The fan cowl 208 is then rotated around the lateral cylinders 302b-c to reach the open position.

[0043] Conversely, the principle of closing the fan cowl 208 consists, from the open position, of moving the fan cowl 208 around the lateral cylinders 302b-c from the open position to the intermediate position, then moving the fan cowl 208 laterally to port for the starboard fan cowl 208, and to starboard for the port fan cowl 208 to reach the closed position.

[0044] Thanks to the offset between the central cylinder 302a and the lateral cylinders 302b-c, the blower hood 208 shifts laterally to move away from the other blower hood 208 or the upper hood 211 and thus can open or close without risk of interactions.

[0045] In the embodiment of the invention presented on the Figs. 3 à 10 The locking means 306 consist of a first pallet 306a attached to the shaft 302 and two first pads 306b-c attached to the frame 402. The first two pads 306b-c are arranged on either side of the first pallet 306a and one of the first pads 306b is arranged so that the first pallet 306a is against it in the closed position of the blower hood 208 and the other of the first pads 306c is arranged so that the first pallet 306a is against it in the intermediate position of the blower hood 208.

[0046] In the embodiment of the invention presented on the Figs. 3 à 10 The stopping means 308 consist, here for each lateral cylinder 302b-c, of a second paddle 308a fixed to the shaft 302 and a second stop 308b fixed to the blower hood 208, here to the fitting 208a. The second stop 308b is arranged so that the second paddle 308a abuts against it in the intermediate position of the blower hood 208. The open position of the blower hood 208 is determined by the maximum rotation that the blower hood can make around the lateral cylinders 302b-c.

[0047] There Fig. 6 shows the locking means 306 in the closed position of the blower hood 208 and the Fig. 7 shows the means of stopping 308 in the closed position of the blower hood 208.

[0048] There Fig. 8 shows the locking means 306 in the intermediate position of the blower hood 208 and the Fig. 9 shows the stopping means 308 in the intermediate position of the blower hood 208.

[0049] There Fig. 10 shows the means of stopping 308 in the open position of the blower hood 208.

[0050] In the closed position ( Fig. 6 ), the first pallet 306a is against the first block 306b, which is here located on the opposite side of the blower hood 208, i.e. on the starboard side for the port blower hood 208 and on the port side for the starboard blower hood 208.

[0051] In the closed position ( Fig. 7 ), the second pallet 308a is against the second block 308b, which is here arranged on the same side as the blower hood 208, that is to say on the starboard side for the starboard blower hood 208 and on the port side for the port blower hood 208.

[0052] The transition to the intermediate position consists of ( Fig. 8 ) consists of moving the blower hood 208 laterally (arrow 80) until the first pallet 306a is against the other first block 306c, the one which is located here on the same side as the blower hood 208, i.e. to starboard for the starboard blower hood 208 and to port for the port blower hood 208.

[0053] During the transition to the intermediate position ( Fig. 9 ), the stopping means 308 remain in the same position except that they have pivoted around the central cylinder 302a.

[0054] The transition to the open position consists of ( Fig. 10 ) to rotate the blower hood 208 around the side cylinders 302b-c causing the second stud 308b to detach from the second vane 308a while the locking means 306 remain in the same position ( Fig. 8 ).

[0055] Conversely, from the open position ( Fig. 10 ) of the blower hood 208, the latter is moved in rotation around the lateral cylinders 302b-c until the second pin 308a is brought against the second vane 308a ( Fig. 9 ) while the blocking means 306 remain in the same position ( Fig. 8 ) to reach the intermediate position of the blower hood 208.

[0056] The transition from the intermediate position to the closed position ( Fig. 6 ) consists of moving the blower hood 208 laterally (opposite of arrow 80) until the first pallet 306a is brought against the first block 306b located on the opposite side of the blower hood 208, while the stopping means 308 remain in the same position ( Fig. 7 ) to the rotation around the first cylinder 302a.

[0057] The positions of the pads relative to the pallets may be different depending on the configuration, for example if the pallet is positioned upwards and not downwards as shown here.

Claims

1. Propulsion system (106) for an aircraft (100), said propulsion system (106) comprising: - a chassis (402), - a nacelle (202) comprising two fan cowls (208), - for each fan cowl (208), at least one articulation system (300) fixed between the chassis (402) and said fan cowl (208), so as to move said fan cowl (208) between a closed position and an open position, and vice versa, and - for each fan cowl (208), a locking means arranged to assume, alternately, a locked position in which it ensures the locking of said fan cowl (208) on the chassis (402) in the closed position and an unlocked position in which it does not ensure the locking of said fan cowl (208) on the chassis (402), in which each articulation system (300) comprises: - a shaft (302) comprising a central cylinder (302a) with an axis (12a) and at least one lateral cylinder (302b-c), each with an axis (12b-c), in which the central cylinder (302a) is movably mounted in rotation on the chassis (402) about its axis (12a), in which said at least one lateral cylinder (302b-c) is movably mounted in rotation on the fan cowl (208) about its axis (12b-c) and in which the axes (12b-c) of said at least one lateral cylinder (302b-c) are coaxial and parallel but distinct from the axis (12a) of the central cylinder (302a), - blocking means (306) arranged to limit the rotation of the central cylinder (302a) relative to the chassis (402) between a first position corresponding to the closed position of the fan cowl (208) and a second position corresponding to an intermediate position of the fan cowl (208) in which the fan cowl (208) is laterally offset from the side corresponding to said fan cowl (208), and - stopping means (308) arranged to allow rotation of the fan cowl (208) relative to said at least one lateral cylinder (302b-c) between a first position corresponding to the intermediate position of the fan cowl (208) and a second position corresponding to the open position of the fan cowl (208) and to prevent the rotation of the fan cowl (208) beyond the intermediate position when moving from the open position, wherein the blocking means (306) consist of a first blade (306a) integral with the shaft (302) and two first pins (306b-c) integral with the chassis (402), wherein the two first pins (306b-c) are arranged on either side of the first blade (306a), wherein one of the first pins (306b) is arranged in such a manner that the first blade (306a) abuts against it in the closed position of the fan cowl (208) and wherein the other of the first pins (306c) is arranged in such a manner that the first blade (306a) abuts against it in the intermediate position of the fan cowl (208).

2. Propulsion system (106) according to Claim 1, characterized in that the stopping means (308) consist of a second blade (308a) integral with the shaft (302) and a second pin (308b) integral with the fan cowl (208) and in that the second pin (308b) is arranged in such a manner that the second blade (308a) abuts against it in the intermediate position of the fan cowl (208).

3. Aircraft (100) comprising an engine and a propulsion system according to any one of the preceding claims in which the engine (204) is integral with the chassis (402) and housed inside the nacelle (202).