AIRCRAFT PROPELLER ASSEMBLY COMPRISING A TURBOJET ENGINE, A MAST AND MEANS OF ATTACHING THE TURBOJET ENGINE TO THE MAST
The propulsion assembly for aircraft turbojet engines redistributes forces through a pin and pallet assembly, central connecting rods, and a triangular shackle, addressing force management issues in existing systems, improving load distribution and safety.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- AIRBUS OPERATIONS (SAS)
- Filing Date
- 2022-01-07
- Publication Date
- 2026-04-10
Smart Images
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Abstract
Description
Title of the invention: PROPULSION ASSEMBLY FOR AN AIRCRAFT COMPRISING A TURBOJET ENGINE, A MAST AND MEANS FOR ATTACHING THE TURBOJET ENGINE TO THE MAST technical field
[0001] The present invention relates to the general field of attaching a turbojet engine under the wing of an aircraft. It relates in particular to a propulsion system comprising a turbojet engine, especially a turbofan engine, a mast, and an attachment device for securing the turbojet engine under the mast. It also relates to an aircraft equipped with such a propulsion system. PREVIOUS STATE OF THE ART
[0002] A prior art propulsion system is fixed under the wing of an aircraft, comprising a turbojet engine and a mounting pylon by means of which the turbojet engine is fixed under the wing. Overall, the mounting pylon comprises a rigid structure, also called the primary structure, carrying first attachment elements for securing the turbojet engine.
[0003] These first fastening elements consist of a front engine attachment, a rear engine attachment, and a device for taking up the thrust forces generated by the turbojet.
[0004] The attachment mast further includes second attachment elements allowing the attachment mast to be fixed to the sail.
[0005] The turbojet engine comprises at the front a fan casing surrounding an annular fan duct, and towards the rear a smaller central casing, enclosing the core of the turbojet engine.
[0006] The front engine mount is interposed between a front end of the rigid structure and an upper front portion of the central casing, and the rear engine mount is interposed between the rigid structure and an upper rear portion of the central casing. The thrust force absorption device for the turbojet engine comprises two connecting rods arranged on either side of a median vertical plane of the turbojet engine and articulated, on one side, to the central casing, and, on the other side, to a single servo arm fixed to the rigid structure. The thrust force absorption device, which consists of the two connecting rods and the servo arm, is designed to absorb all or most of the forces directed along the longitudinal X direction of the turbojet engine.
[0007] The front engine mount has a connecting rod on either side of the mast, and each connecting rod is hinged at one end to the mast and hinged at the other end to the central housing. One of the connecting rods is fixed by two connection points to the mast and by one connection point to the central casing, and the second connecting rod is fixed by one connection point to the mast and by one connection point to the central casing.
[0008] The forward engine mount allows for the absorption of some of the forces directed along the Y and Z directions, as well as a torsional moment Mx. The aft engine mount comprises a triangular shackle that is hinged at one of its upper ends to the mast and hinged at one of its lower ends to the engine. This triangular shackle is thus composed of an upper attachment point on the mast side, positioned on the mast's median plane under its lower face, and two lower attachment points on the engine side, positioned on either side of the mast's median plane on the engine casing. This arrangement also allows for the absorption of some of the forces directed along the Y and Z directions.
[0009] Although such a structure gives satisfaction, it is desirable to find an arrangement which allows a different resumption of forces in particular at the level of the front engine attachment and the thrust force resumption device. Description of the invention
[0010] An object of the present invention is to propose a propulsion assembly comprising a turbojet, a mast and a hooking device for hooking the turbojet under the mast, and which allows a different redistribution of the forces.
[0011] To this end, a propulsion system for an aircraft is proposed, said propulsion system comprising:
[0012] - a turbojet engine comprising a central casing around a longitudinal axis and presenting a vertical median plane passing through the longitudinal axis,
[0013] - a mounting mast having a rigid structure with a front wall,
[0014] - a front engine mount,
[0015] - a rear engine mount interposed between a median zone of the rigid structure and an upper rear portion of the central casing, and
[0016] - a device for recovering the thrust forces generated by the turbojet engine,
[0017] where the front motor attachment comprises a pin and an assembly of at least one pallet, where the pin is cylindrical with a first end fixed to the front wall of the rigid structure of the reactor mast and a second end projecting forward, where the axis of the pin is parallel to the longitudinal axis and in the median plane, where each pallet of the pallet assembly has a bore passing through said pallet, the axis of which is parallel to the axis of the pin, where the bore of each pallet is fitted onto the pin, where each pallet is hinged on either side of the median plane to an upper part of the central casing by means of a connection point to a front fitting fixed to the upper part of the central casing, and
[0018] where the turbojet thrust force recovery device comprises two central connecting rods arranged on either side of the median plane, for each central connecting rod, a first fitting attached to the rigid structure and a second fitting attached to a front part of the central casing, where the first two fittings are independent of each other, where each central connecting rod is fixed in an articulated manner by one of its ends to the first fitting and by the other of its ends to the second fitting.
[0019] With such an arrangement, the resumption of efforts takes place in pairs at the level of three different planes.
[0020] Advantageously, the pawl consists of two half-pawns, each taking the form of a half-cylinder, each half-pawn having a first end and a second end which project forward, and the first end of each half-pawn is attached to a half-shoe which is itself attached to the front wall.
[0021] Advantageously, each half-shoe comprises a support plate which is supported against the front wall and fixed to said front wall of the rigid structure of the reactor mast and ribs integral with the support plate and perpendicular to the support plate.
[0022] Advantageously, a rib of each half-shoe has a vertical flat face, the vertical flat face of one half-shoe is in contact with the vertical flat face of the other half-shoe, and the contacting flat surfaces are in the median plane.
[0023] Advantageously, the propulsion assembly includes a sleeve which fits onto the two half-pins and which fits into the bore of each pallet.
[0024] Advantageously, each pallet has on either side of the median plane, a support zone, and for each support zone, the propulsion assembly has a stop which is opposite the support zone and integral with the rigid structure of the reactor mast, and in normal operation, each support zone remains at a distance from the associated stop and in degraded operation, one of the support zones comes to rest against the associated stop.
[0025] The invention also proposes an aircraft comprising a wing and a propulsion assembly according to one of the preceding variants, the rigid structure of which is fixed under the wing. Brief description of the drawings
[0026] 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:
[0027] [Fig-1] represents a side view of an aircraft according to the invention,
[0028] [Fig.2] is a perspective view of a propulsion assembly according to the invention,
[0029] [Fig.3] is an enlargement of the front engine mount of [Fig.2],
[0030] [Fig.4] is a cross-sectional view of the front engine mount of [Fig.3] by plane IV, and
[0031] [Fig.5] is an enlargement of detail V of [Fig.4].
[0032] DETAILED STATEMENT OF IMPROVEMENTS
[0033] Fig. 1 shows an aircraft 50 which has a wing 52 under which is mounted a propulsion unit 100 according to the invention and which includes a turbojet 102 and a towing mast 104.
[0034] By convention, X is called the longitudinal direction of the turbojet 102, this direction X being parallel to a longitudinal axis of this turbojet 102. On the other hand, Y is called the transverse direction of the turbojet 102 which is horizontal when the aircraft is on the ground, and Z is called the vertical direction or vertical height when the aircraft is on the ground, these three directions X, Y and Z being orthogonal to each other.
[0035] On the other hand, the terms "forward" and "rear" are to be considered in relation to a direction of advance of the aircraft 50 during the operation of the turbojet 102, this direction being schematically represented by the arrow 107.
[0036] Figure 2 shows the propulsion assembly 100, which includes the turbojet engine 102 and the mounting mast 104 by which the turbojet engine 102 is attached to the wing 52 (not shown in Figures 2 to 5). The mounting mast 104 is represented here by its rigid structure 106, also called the primary structure, which carries first attachment elements 150 for attaching the turbojet engine 102. The rigid structure 106 extends along the longitudinal direction X between a front end and a rear end, between which lies a mid-section, and the rigid structure 106 is attached under the wing 52.
[0037] In the embodiment of the invention shown in [Fig.2], the rigid structure 106 takes the form of a box which includes a lower wall 106a, an upper wall 106b, two side walls 106c-d and a front wall 106e oriented towards the front.
[0038] These first fixing elements consist of a front engine attachment 152, a rear engine attachment 154, and a device for taking back the thrust forces of the turbojet 156 to take back the thrust forces generated by the turbojet 102.
[0039] The attachment mast 104 further comprises second attachment elements allowing the attachment of the attachment mast 104, and more particularly of the rigid structure 106, to the wing 52. The second attachment elements are not shown in Figs. 2 to 5, as they are outside the scope of the invention and can take any form known to those skilled in the art.
[0040] The turbojet 102 has at the front a fan casing surrounding a duct annular fan housing (also not shown here), and inside and towards the rear of the fan housing, a smaller central housing 112, enclosing the core of the turbojet 102 around the longitudinal direction X.
[0041] The attachment mast 104 is globally symmetrical with respect to a vertical median plane XZ of the turbojet 102 which passes through the longitudinal axis of the turbojet 102 and which is subsequently called the median plane P.
[0042] The front motor attachment 152 is interposed directly between a front end of the rigid structure 106, here the front wall 106e, and an upper and front part of the central housing 112 by means of front fittings 153 integral with said upper and front part of the central housing 112. In the embodiment of the invention shown in [Fig.2] and [Fig.3], there are two front fittings 153 on either side of the median plane P, but these two front fittings 153 can be joined together and form a single front fitting.
[0043] The rear engine attachment 154 is interposed directly between the middle area of the rigid structure 106, here the lower wall 106a, and a rear fitting 155 integral with a rear upper part of the central casing 112.
[0044] The thrust force recovery device of the turbojet 156 comprises two central connecting rods 158 arranged on either side of the median plane P and articulated, on the one hand, at the front, on a front part of the central casing 112, and, on the other hand, at the rear on the rigid structure 106 between the front end and the median area.
[0045] The front motor attachment 152 includes a pin 164 (also called a "spigot") which is cylindrical, which has a first end 502a fixed to the front wall 106e and which projects a second end 502b forward and whose axis is parallel to the longitudinal direction X. The axis of the pin 164 is in the median plane P.
[0046] The front motor attachment 152 also includes an assembly 166 of at least one pallet, which here consists of two pallets 166a-b for safety reasons and to double the load paths in order to ensure the connection is maintained even in the event of damage and loss of one of the connection elements. The pallets 166a-b are arranged one behind the other along the longitudinal direction X.
[0047] Each pallet 166a-b of the pallet assembly 166 has a bore 168 through said pallet 166a-b and whose axis is parallel to the axis of the pin 164. The bore 168 of each pallet 166a-b is fitted onto the pin 164 ensuring rotational freedom of each pallet 166a-b on the pin 164.
[0048] Each pallet 166a-b of the pallet assembly 166 is fixed in an articulated manner to each front fitting 153, that is to say that each pallet 166a-b is fixed in an articulated manner on either side of the median plane P to the upper and front part of the central housing 112 by means of a single point of connection to each front fitting 153.
[0049] In the embodiment of the invention presented here, for each pallet 166a-b, the connection point to each front fitting 153 is made up of a female clevis made in the front fitting 153, a male clevis made by the pallets 166a-b and a shear axis, for example simple, which passes through the female clevis and fits into the male clevis through a ball joint connection.
[0050] The pin 164 allows a resumption of the forces in Y and Z in a frontal plane perpendicular to the longitudinal direction X and containing the first end of the pin 164.
[0051] The front fittings 153, the pallets 166a-b and the pin 164 define a primary path of forces.
[0052] The rear engine attachment 154 includes a triangular shackle 157 fixed in an articulated manner to the rear fitting 155 and to an upper fitting 159 integral with the rigid structure 106, here of the lower wall 106a.
[0053] In the embodiment of the invention, the triangular shackle 157 comprises three attachment points and is fixed by one attachment point to the upper fitting 159 and by two attachment points to the rear fitting 155. For safety reasons and in order to ensure the maintenance of the connection even in the event of damage and loss of one of the elements of the connection, the triangular shackle 157 is doubled and therefore consists of two pallets juxtaposed along a longitudinal axis parallel to the longitudinal axis X.
[0054] In the embodiment of the invention presented here, each connection point of the triangular shackle 157 to the upper fitting 159 and to the rear fitting 155, is constituted by a female clevis made in the fittings 155 and 159, by a male clevis made of the triangular shackle 157 and by a shear pin, for example simple, which passes through the female clevis and fits into the male clevis in a bore of the triangular shackle 157 provided for this purpose through a ball joint.
[0055] The triangular shackle 157 allows the forces to be taken up in Z and Y in a rear plane perpendicular to the longitudinal direction X and containing the three connection points of the triangular shackle 157.
[0056] The device for recovering the thrust forces of the turbojet engine 156 comprises, for each central connecting rod 158, a first fitting 204 integral with the rigid structure 106 and a second fitting 206 integral with the central casing 112.
[0057] The first two fittings 204 are independent of each other and each first fitting 204 is fixed on one side of the rigid structure 106 to one of the side walls 106c-d.
[0058] Each central connecting rod 158 is fixed in an articulated manner by one of its ends to the first fitting 204 and by the other of its ends to the second fitting 206. Each central connecting rod 158 is thus fixed by a connection point to the first fitting 204 and by a connection point to the second fitting 206.
[0059] In the embodiment of the invention presented here, each connection point of a central connecting rod 158 to the fittings 204 and 206 is constituted by a female clevis made respectively in the fittings 204 and 206, by a male clevis made by the central connecting rod 158 at each of its ends and by a shear axis, for example simple, which passes through the female clevis and fits into the male clevis in a bore of the central connecting rod 158 provided for this purpose through a ball joint connection.
[0060] Due to the separation of the first fittings 204, each central connecting rod 158 allows a force to be taken up along the central connecting rod 158 and this force has components in X, Y and Z in a central plane passing through the axis of the two central connecting rods 158 and therefore containing the two points of connection of the central connecting rods 158 to the first fittings 204.
[0061] The line 162 passing through the center of the connection point of the triangular shackle 157 to the upper fitting 159 and the center of the pin 164 is a torsion line (also called a "swing line"). The axes of the two central connecting rods 158 meet at an intersection point 163. Due to the design presented here, the distance between the intersection point 163 and the torsion line 162 is relatively large, which results in reduced forces in the central connecting rods 158, known as the 'thrust' rods.
[0062] At each of the front, rear, and central planes, the first fixing elements 150 allow for the transfer of two forces at each plane, thus improving load distribution. The three interface planes cooperate to transfer the bending (My, Mz) and torsional (Mx) moments.
[0063] The moment Mx is compensated by the forces in the two central connecting rods 158 and the Y component of the forces contained in the front and rear planes.
[0064] The moment My is compensated by the Z forces at the level of the two front and rear planes and the X component of the forces of the two central connecting rods 158.
[0065] The moment Mz is compensated by the Y forces at the level of the two front and rear planes and the X component of the forces of the two central connecting rods 158.
[0066] Fig. 4 and Fig. 5 show a particular structure of the 164th pawl.
[0067] The pawn 164 consists of two half-pawns 164a-b, each taking the form of a The two half-cylinders are joined and arranged against each other to form a cylinder. In the embodiment of the invention presented here, the contact plane between the two half-pins 164a-b is the median plane P.
[0068] Like the pin 164, each half-pin 164a-b has a first end 502a fixed to the front wall 106e and a second end 502b projecting forward. The first end 502a of each half-pin 164a-b is indirectly fixed to the front wall 106e, and the first end 502a of each half-pin 164a-b is thus fixed to a half-shoe 504a-b which is itself fixed to the front wall 106e. The half-shoe 504 is fixed to the front wall 106e, for example, by clamping bolts.
[0069] The placement of two half-pawns 164a-b ensures a path of effort even if one of the half-pawns 164a-b breaks.
[0070] In the embodiment of the invention shown in [Fig.3], each half-shoe 504a-b comprises a support plate 506 which is supported against the front wall 106e and fixed to said front wall 106e, and ribs 508 integral with the support plate 506 and perpendicular to the latter to ensure good rigidity of the support plate 506.
[0071] To ensure proper support of the two half-shoes 504a-b, a rib 508 of each half-shoe 504a-b has a vertical flat face, and the vertical flat face of one half-shoe 504a bears against the vertical flat face of the other half-shoe 504b. The bearing flat surfaces are in the median plane P.
[0072] The propulsion assembly 100 also includes a sleeve 510 which fits onto the two half-pins 164a-b and which fits into the bore 168 of each pallet 166a-b. Thus, even if one half-pin 164a-b breaks, the broken elements are held in the sleeve 510 which ensures the continuity of the connection.
[0073] Figs. 2 and 3 show a particular arrangement of a 'waiting fail-safe' function, that is to say, a 'waiting safety' function which is activated only in the event of damage and loss of one of the elements of the link.
[0074] Each pallet 166a-b has on either side of the median plane P, a support area 550 which is here globally horizontal in use.
[0075] For each support zone 550, the propulsion assembly 100 includes a stop 552 which is opposite the support zone 550 and which is integral with the rigid structure 106 of the reactor mast 104. In the embodiment of the invention presented here, each stop 552 is a portion of the ribs 508 of the half-shoes 504a-b.
[0076] In normal operation, each support zone 550 remains at a distance from the associated stop 552. In degraded operation, in the event of a break or loss of one of the two connections between the pallets 166 ab and the front fittings 153, the pallets 166a-b will tend to tilt around the pin 164 and one of the support zones 550 will come to rest against the associated stop 552, thus limiting the rotation of the pallets 166a-b.
[0077] With such an arrangement, it is not necessary to double the front fittings 153 or the connecting axes of said front fittings 153.
Claims
Demands
1. Propulsion assembly (100) of an aircraft (50), said propulsion assembly (100) comprising: - a turbojet engine (102) comprising a central casing (112) around a longitudinal axis and having a vertical median plane (P) passing through the longitudinal axis, - a mounting mast (104) having a rigid structure (106) with a front wall (106e), - a front engine mount (152), - a rear engine mount (154) interposed between a median area of the rigid structure (106) and a rear upper part of the central casing (112), and - a device (156) for recovering the thrust forces generated by the turbojet engine (102), where the forward engine attachment (152) comprises a pin (164) and an assembly (166) of at least one pallet (166a-b), where the pin (164) is cylindrical with a first end integral with the front wall (106e) of the rigid structure (106) of the engine pylon (104) and a second end projecting forward, where the axis of the pin (164) is parallel to the longitudinal axis and in the median plane (P), where each pallet (166a-b) of the pallet assembly (166) has a bore (168) passing through said pallet (166a-b), the axis of which is parallel to the axis of the pin (164), where the bore (168) of each pallet (166a-b) is fitted onto the pin (164), where each pallet (166a-b) is hinged at both ends on the other side of the median plane (P) to an upper part of the central housing (112) via a connection point to a front fitting (153) integral with the upper part of the central housing (112), and where the device (156) for absorbing the thrust forces of the turbojet engine comprises two central connecting rods (158) arranged on either side of the median plane (P), for each central connecting rod (158), a first fitting (204) integral with the rigid structure (106) and a second fitting (206) integral with a front portion of the central casing (112), where the first two fittings (204) are independent of each other, where each central connecting rod (158) is hinged at one end to the first fitting (204) and at the other end to the second fitting (206), where each blade (166a-b) comprises, on either side of the median plane (P), a horizontal bearing area (550), where for each support zone (550), the propulsion assembly (100) includes a stop (552) which is opposite the support zone (550) and integral with the rigid structure (106) of the reactor mast (104), and where in normal operation, each support zone (550) remains at a distance from the associated stop (552) and in degraded operation, in the event of a break or loss of one of the two links between the vanes (166a-b) and the front fittings (153), one of the support zones (550) comes to rest against the associated stop (552).
2. Propulsive assembly (100) according to claim 1, characterized in that the pin (164) is made up of two half-pins (164a-b) where each takes the form of a half-cylinder, in that each half-pin (164a-b) has a first end (502a) and a second end (502b) which project forward, and in that the first end (502a) of each half-pin (164a-b) is integral with a half-shoe (504a-b) which is itself integral with the front wall (106e).
3. Propulsion assembly (100) according to claim 2, characterized in that each half-shoe (504a-b) comprises a support plate (506) which is supported against the front wall (106e) and fixed to said front wall (106e) of the rigid structure (106) of the reactor mast (104) and ribs (508) integral with the support plate (506) and perpendicular to the support plate (506).
4. Propulsive assembly (100) according to claim 3, characterized in that a rib (508) of each half-shoe (504a-b) has a vertical flat face, in that the vertical flat face of one half-shoe (504a) is in contact with the vertical flat face of the other half-shoe (504b), and in that the contacting flat surfaces are in the median plane (P).
5. Propulsive assembly (100) according to any one of claims 2 to 4, characterized in that it comprises a sleeve (510) which fits onto the two half-pins (164a-b) and which fits into the bore (168) of each pallet (166a-b).
6. Aircraft (100) comprising a wing (52) and a propulsion assembly (100) according to any one of the preceding claims, the rigid structure (106) of which is fixed under the wing (52).