ENGINE ASSEMBLY FOR AN AIRCRAFT

Abstract

AIRCRAFT MOTORIZATION ASSEMBLY The invention relates to an aircraft propulsion assembly comprising a primary structure (102a), a secondary structure (102b) located in front of the primary structure (102a) and rotatable on the primary structure (102a) about an axis of rotation (60), on either side of a vertical median plane (P), a fan cowl hinged to the secondary structure (102b), an air inlet structure (108a) located in front of the secondary structure (102b), and locking means (140) which, in a stopped position, lock the secondary structure (102b) relative to the air inlet structure (108a) with an operating clearance between the locking means (140) and the air inlet structure (108a). With such an arrangement, the secondary structure is reduced in size and the risk of misalignment is also reduced. Fig. 6

Description

Title of the invention: MOTORIZATION ASSEMBLY FOR AN AIRCRAFT technical field

[0001] The present invention relates to an aircraft engine assembly, said engine assembly comprising an upper structure on which fan cowls are hinged and which includes means for securing it to an air intake structure. The invention also relates to an aircraft comprising at least one such engine assembly. PREVIOUS STATE OF THE ART

[0002] An aircraft comprises a fuselage on each side of which a wing is attached. Under each wing is suspended at least one engine assembly comprising a reactor pylon fixed under the wing and carrying a turbojet engine, for example a turbofan engine.

[0003] The turbojet engine comprises, from front to rear, an air intake through which outside air is admitted into the turbojet, a fan, and an engine. These elements are surrounded by a nacelle which is attached partly to the engine pylon and partly to the turbojet engine structure.

[0004] To this end, the reactor mast includes a primary structure which is fixed between the reactor mast and the turbojet and which transmits the forces which are generated by the turbojet to the reactor mast.

[0005] The nacelle includes, among other things, a lip which surrounds the air inlet and two fan cowls which are arranged at the rear of the lip and on either side of a vertical median plane of the turbojet.

[0006] At the front of the primary structure, the engine pylon has a secondary structure which is part of the upper section of the turbojet and is rigidly connected to the primary structure. This secondary structure extends behind the lip to the primary structure. Each fan cowl is hinged to the secondary structure so that it can be opened when necessary.

[0007] When the aircraft is in flight, the primary engine structure is subjected to significant stresses that cause movement within the primary structure. Due to the rigid connection between the primary and secondary structures, the latter deforms, and a misalignment may occur at the junction between the lip and the secondary structure. This misalignment then results in detrimental drag. Furthermore, the dimensions of the turbojet engine tend to increase, and the space available for arranging the primary structure is correspondingly reduced. Description of the invention

[0008] An object of the present invention is to provide a motorization assembly which limits the risks of misalignment of the primary structure with respect to the lip.

[0009] To this end, a propulsion system for an aircraft is proposed, said propulsion system having a vertical median plane and comprising:

[0010] - a primary structure,

[0011] - a secondary structure arranged in front of the primary structure, where the structure The secondary structure is mounted to rotate freely on the primary structure around an axis of rotation perpendicular to the vertical median plane.

[0012] - on either side of the vertical median plane, a blower hood mounted hinged on the secondary structure,

[0013] - an air inlet structure arranged at the front of the secondary structure, and

[0014] - stopping means which, in a stopped position, block the secondary structure compared to the air inlet structure with an operating clearance between the stopping means and the air inlet structure.

[0015] With such an arrangement, the secondary structure is reduced and the risks of dislodgement are also reduced.

[0016] Advantageously, each blower hood is fixed to the secondary structure by two hinges and the two blower hoods are linked together by a floating hinge.

[0017] Advantageously, the stopping means are movable to a free position in which the stopping means leave the secondary structure free with respect to the air inlet structure.

[0018] According to a particular embodiment, the stopping means take the form of a stud mounted on the secondary structure, respectively the air inlet structure and a hole provided in the air inlet structure, respectively the secondary structure and in an insertion position corresponding to the stopping position, the stud is inserted into the hole, and where the diameters of the hole and the stud have an operating clearance between them.

[0019] Advantageously, the stud is movable towards a retracted position corresponding to the free position in which it is out of the hole.

[0020] According to a particular embodiment, the stopping means take the form of a pair of jaws integral with the secondary structure with an operating clearance between the jaws and the air structure.

[0021] Advantageously, the stopping means comprise:

[0022] - a stop integral with the air inlet structure,

[0023] - a fixed jaw integral with the secondary structure and arranged to come against an upper face of the stop in the closed position,

[0024] - a movable jaw mounted articulated on the secondary structure between a position tightened corresponding to the stop position in which the movable jaw is against an underside of the stop, and a loosened position corresponding to the free position in which the movable jaw is away from the underside of the stop, and

[0025] - locking means arranged to lock the movable jaw in a closed position and which are retractable to allow passage of the movable jaw in the loosened position.

[0026] Advantageously, the locking means are arranged to lock the movable jaw in the loosened position.

[0027] The invention also proposes an aircraft comprising at least one engine assembly according to one of the preceding variants. Brief description of the drawings

[0028] 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:

[0029] [Fig-1] is a side view of an aircraft comprising a propulsion assembly according to the invention,

[0030] [Fig.2] is a perspective view of part of a motorization assembly according to the invention,

[0031] [Fig.3] is a perspective view from inside the turbojet of the secondary structure and fan cowls of the engine assembly according to the invention,

[0032] [Fig.4] is a side view of the means for stopping the motorization assembly according to the invention in the stopped position,

[0033] [Fig.5] is a view similar to that of [Fig.4] for a free position of the stopping means,

[0034] [Fig.6] is a schematic side view representation of a section at a vertical median plane of the motorization assembly according to the invention with the secondary structure in the closed position, and

[0035] [Fig.7] is a view similar to that of [Fig.6] for an open position of the secondary structure.

[0036] DETAILED STATEMENT OF IMPROVEMENTS

[0037] In the following description, terms relating to a position are taken with reference to an aircraft in a forward position as shown in [Fig.1] and where arrow 107 shows the direction of forward movement of the aircraft in flight.

[0038] Fig. 1 shows an aircraft 10 comprising a fuselage 11 on each side of which is fixed a wing 12 which carries at least one engine assembly 100 according to the invention. Figure 2 shows the propulsion assembly 100 which includes a reactor mast 102 having a primary structure 102a and a secondary structure 102b. The propulsion assembly 100 also includes a turbojet engine 106, in particular a turbofan engine.

[0039] The primary structure 102a is fixed between a wing structure 12 and a turbojet structure 106. The secondary structure 102b is disposed in the upper part (at 12 o'clock) of the turbojet 106 and in front of the primary structure 102a.

[0040] In the following description, and by convention, X is called the longitudinal axis of the turbojet 106 which is parallel to the longitudinal axis of the aircraft 10 or roll axis, oriented positively in the direction of forward movement of the aircraft 10, Y is called the transverse axis which is parallel to the pitch axis of the aircraft 10 which is horizontal when the aircraft 10 is on the ground, and Z is called the vertical axis which is parallel to the yaw axis when the aircraft 10 is on the ground, these three directions X, Y and Z being orthogonal to each other.

[0041] The motorization assembly 100 also has a vertical median plane P defined by the X and Z axes.

[0042] The turbojet 106 has at the front, an air inlet 108 which is delimited by a lip 108b which constitutes a cowling fixed on an air inlet structure 108a (Figs. 4 to 7) which is arranged at the front of the secondary structure 102b.

[0043] At the rear of the air inlet 108, the turbojet 106 comprises a fan and then an engine. The fan and the engine are surrounded by a nacelle 110 which is attached partly to the engine pylon 102 and partly to a structure of the turbojet 106.

[0044] The nacelle 110 includes, among other things, on either side of the vertical median plane P, a fan hood 104. Each fan hood 104 is hinged on the secondary structure 102b between a closed position in which the fan hoods 104 are tightened around the fan and an open position in which the fan hoods 104 are pulled away from the fan, particularly during maintenance operations. Since each fan hood 104 is hinged on the upper part of the secondary structure 102b, the upper edge of the fan hood 104 is hinged to the secondary structure 102b, and the open position corresponds to a lifting of the lower edge of the fan hood 104.

[0045] The articulation of each blower hood 104 corresponds to a rotation around an opening axis 204 which is parallel to the plane P and globally parallel to the longitudinal axis X. The opening axes 204 of the two blower hoods 104 are on either side of the vertical median plane P.

[0046] Conventionally, the closed position of the blower hoods 104 is ensured by latches located along the lower edges (at 6 o'clock) of the blower hoods 104. Conventionally, in the closed position, the arc-shaped edges Fan cowls 104 are supported at the front against the edges of the air inlet structure 108a and at the rear against a structure of the turbojet 106, such as a thrust reverser structure.

[0047] As shown in [Fig.3], the secondary structure 102b consists here of a chassis 202a and a hood 202b fixed to the outside of the chassis 202a.

[0048] As shown in Figs. 6 and 7, the secondary structure 102b, and more particularly here the chassis 202a, is mounted movably in rotation on the primary structure 102a around an axis of rotation 60. This rotation is achieved by all suitable means such as clevis systems, hinges, etc.

[0049] The axis of rotation 60 is here perpendicular to the vertical median plane P.

[0050] The free rotation of the secondary structure 102b relative to the primary structure 102a limits the movements of the secondary structure 102b even when the primary structure 102a moves in flight. By limiting the displacements of the secondary structure 102b, the misalignment of the secondary structure 102b relative to the lip 108b is thus reduced.

[0051] When the aircraft 10 is in flight and the fan cowls 104 are in the closed position and locked by the latches, the secondary structure 102b cannot pivot significantly due to the clamping forces exerted on the fan cowls 104, and the secondary structure 102b is therefore in a closed position. However, on the ground, when the fan cowls 104 are unlocked and placed in the open position, the secondary structure 102b could pivot significantly and unintentionally, for example, under the effect of wind, and thus move into an open position.

[0052] To prevent such an unwanted tipping, the drive assembly 100 includes stop means 140 which, in a stopped position, lock the secondary structure 102b relative to the air inlet structure 108a with an operating clearance between the stop means 140 and the air inlet structure 108a. [Fig. 4] shows the clearance "J1+J2" which limits the movement of the secondary structure 102b while allowing a small displacement, thus preventing stress from occurring in the surrounding elements.

[0053] In the embodiment of the invention shown in the Figs., the stopping means 140 take the form of a pair of jaws fixed to the secondary structure 102b with a clearance which is divided into two clearances J1 and J2 between each jaw and the air structure 108a. According to a particular embodiment, the clearance is between 3 mm and 10 mm.

[0054] According to another particular embodiment not shown, the stopping means 140 take the form of a block mounted on the secondary structure 102b (or the structure air inlet 108a) and a hole provided in the air inlet structure 108a (or the secondary structure 102b) and where, in an insertion position corresponding to the stop position, the stud is inserted into the hole and where the diameters of the hole and the stud also have an operating clearance allowing a slight movement of the secondary structure 102b. The clearance is, for example, between 0.5 mm and 3 mm.

[0055] The clearances described above are large enough to allow movement of the secondary structure 102b relative to the air intake structure 108a and small enough so that in flight, the secondary structure 102b and the air intake structure 108a do not come into conflict with each other and do not generate interaction forces between them.

[0056] In the embodiment of the invention shown in [Fig. 3], each blower hood 104 is attached to the secondary structure 102b by two hinges 30a-b. Each hinge 30a-b here takes the form of a fitting 31a integral with the associated blower hood 104 and mounted articulated on the frame 202a around the opening axis 204.

[0057] Here, the two blower hoods 104 are also linked together by a floating hinge 30c which will be active when one of the other two hinges 30a-b is defective. The floating hinge 30c comprises, for each blower hood 104, a fitting 31b integral with said blower hood 104 and a bar 32 mounted articulated between the two fittings 31b at each opening axis 204. The bar 32 is thus free relative to the frame 202a and connected only to the fittings 31b.

[0058] It may be necessary for the secondary structure 102b to be freely mobile towards the open position, for example during ground maintenance operations.

[0059] The stop means 140 must then be able to be moved to a free position in which the stop means 140 leave the secondary structure 102b free relative to the air inlet structure 108a, thereby allowing the rotation of the secondary structure 102b relative to the primary structure 102a over a greater amplitude and towards the open position.

[0060] The secondary structure 102b is thus mobile in rotation between the closed position ([Fig.6]) in which the hood 202b is pressed against the air inlet structure 108a and is thus in continuity with the lip 108b and the hood 202b of the secondary structure 102a and the open position in which the hood 202b is moved away from the air inlet structure 108a.

[0061] Due to the position in the upper part of the secondary structure 102b, the open position corresponds to a lifting of a front edge of the secondary structure 102b.

[0062] In the case of the stop means 140 in the form of a stud, the stud can be moved into a retracted position corresponding to the free position in which it is out of the associated hole.

[0063] The block is moved, for example, by a linkage system accessible from outside the platform 110 by a technician. Alternatively, the linkage system can be combined with the locks that secure the blower hoods 104, and moving the lock to an unlocked position acts on the linkage system to move the block to its inserted position, and moving the locks to a locked position acts on the linkage system to move the block to its retracted position.

[0064] Figs. 4 and 5 show the particular embodiment where the stopping means 140 take the form of a pair of jaws. Figs. 4 and 6 show the stopping position and Figs. 5 and 7 show the free position where the jaws are sufficiently separated to allow free movement of the secondary structure 102b relative to the air inlet structure 108a.

[0065] The stopping means 140 further comprise a stop 142 which is integral with the air inlet structure 108a.

[0066] The stopping means 140 also include a pair of jaws with a fixed jaw 144 which is integral with the secondary structure 102b and a movable jaw 146 mounted articulated on the secondary structure 102b.

[0067] The fixed jaw 144 is arranged to come against an upper face of the stop 142 in the closed position of the secondary structure 102b and in the stop position.

[0068] The movable jaw 146 is movable between a clamped position corresponding to the stop position in which the movable jaw 146 is against an underside of the stop 142 and a loosened position corresponding to the free position in which the movable jaw 146 is away from the underside of the stop 142.

[0069] The movable jaw 146 is movable around a locking axis 150 which is here perpendicular to the vertical median plane P.

[0070] Here, it is said that the movable jaw 146 is at a distance from the lower face of the stop 142 when the secondary structure 102b is free to move towards the open position.

[0071] Here, it is said that the jaws 144 and 146 are against the stop 142 at the operating clearances J1, J2 close to.

[0072] The stopping means 140 also include locking means 148 which are arranged to lock the movable jaw 146 in the closed position and which are retractable to allow the passage of the movable jaw 146 into the loosened position.

[0073] In the embodiment of the invention presented here, the locking means 148 take the form of a locking stud 148 which is simultaneously inserted into an orifice 148a of the movable jaw 146 and an orifice 148b of the secondary structure 102b, here of the chassis 202a.

[0074] When the locking pin 148 is thus removed, the movable jaw 146 can freely pivot around the locking axis 150 to disengage from the stop 142 and move into the loosened position.

[0075] To keep the movable jaw 146 away from the stop 142, i.e. in the loosened position, the locking means 148 are also arranged to lock the movable jaw 146 in the loosened position.

[0076] Here, the locking stud 148 is inserted into the orifice 148a of the movable jaw 146 and another orifice 148c of the secondary structure 102b.

[0077] These manipulations of the locking pin 148 are carried out for example by hand when the blower hoods 104 are in the open position or when they are disassembled.

Claims

Demands

1. A propulsion assembly (100) for an aircraft (10), said propulsion assembly (100) having a vertical median plane (P) and comprising: - a primary structure (102a), - a secondary structure (102b) arranged in front of the primary structure (102a), where the secondary structure (102b) is movably mounted for rotation on the primary structure (102a) about an axis of rotation (60) perpendicular to the vertical median plane (P), - on either side of the vertical median plane (P), a fan cowl (104) hinged to the secondary structure (102b), - an air intake structure (108a) arranged in front of the secondary structure (102b), and - locking means (140) which, in a stopped position, lock the secondary structure (102b) relative to the air intake structure (108a) with an operating clearance between the stopping means (140) and the air inlet structure (108a).

2. Motorization assembly (100) according to claim 1, characterized in that each blower hood (104) is fixed to the secondary structure (102b) by two hinges (30a-b) and in that the two blower hoods (104) are linked together by a floating hinge (30c).

3. Motorization assembly (100) according to any one of claims 1 or 2, characterized in that the stop means (140) are movable to a free position in which the stop means (140) leave the secondary structure (102b) free with respect to the air inlet structure (108a).

4. Motorization assembly (100) according to any one of claims 1 to 3, characterized in that the stopping means (140) take the form of a stud mounted on the secondary structure (102b), respectively the air inlet structure (108a) and of a hole provided in the air inlet structure (108a), respectively the secondary structure (102b) and in that in an insertion position corresponding to the stopping position, the stud is inserted into the hole and where the diameters of the hole and the stud have an operating clearance between them.

5. A motorization assembly (100) according to claim 4 when it depends on claim 3, characterized in that the pin is movable to a retracted position corresponding to the free position in which it is out of the hole.

6. Motorization assembly (100) according to any one of claims 1 to 3, characterized in that the stopping means (140) take the form of a pair of jaws integral with the secondary structure (102b) with an operating clearance between the jaws and the air structure (108a).

7. A motorization assembly (100) according to claim 6, characterized in that the stopping means (140) comprise: - a stop (142) integral with the air inlet structure (108a), - a fixed jaw (144) integral with the secondary structure (102b) and arranged to abut an upper face of the stop (142) in the closed position, - a movable jaw (146) articulated on the secondary structure (102b) between a closed position corresponding to the stopped position in which the movable jaw (146) is against an underside of the stop (142) and a loosened position corresponding to the free position in which the movable jaw (146) is away from the underside of the stop (142), and - locking means (148) arranged to lock the movable jaw (146) in the closed position and which are retractable to allow the passage of the movable jaw (146) in the loosened position.

8. Motorization assembly (100) according to claim 7, characterized in that the locking means (148) are arranged to lock the movable jaw (146) in the loosened position.

9. Aircraft (50) comprising at least one engine assembly (100) according to any one of the preceding claims.

Images