Aircraft propulsion assembly having jet engine, pylon and means for attaching jet engine to pylon

Abstract

The invention relates to a propulsion assembly (100) for an aircraft, the propulsion assembly (100) having: a jet engine (105) having a central housing and a fan housing (102a) about a longitudinal axis (X) and having a vertical median plane (P) through the longitudinal axis (X); an attachment pylon (104) having a rigid structure (106) in the form of a box having a front wall (106d) and an upper spar (106b) extending forward relative to the front wall (106d); a front engine attachment (153) fixed between the upper region (103) of the center housing (102b) and the lower end of the front wall (106b); and a complementary front engine attachment secured between the upper region of the fan housing and the front end of the upper spar (106b). In this arrangement, the size of the attachment is reduced.

Description

Technical Field

[0001] The invention relates to the general field of attaching a jet engine under the wing of an aircraft. It relates in particular to a propulsion assembly comprising a jet engine, in particular a turbofan engine, a pylon and an attachment device intended to attach the jet engine under the pylon. The invention also relates to an aircraft equipped with such a propulsion assembly. Background Art

[0002] Prior art propulsion assemblies are fastened under the wing of an aircraft, the wing having a jet engine and an attachment pylon, the jet engine being fastened under the wing via the attachment pylon. Typically, the attachment pylon has a rigid structure, also referred to as a primary structure, carrying a first fastening element intended to attach the jet engine.

[0003] These first fastening elements are formed by a front engine attachment, a rear engine attachment and a device for reacting the thrust generated by the jet engine.

[0004] The attachment pylon also has a second fastening element which allows the attachment pylon to be fastened to the wing.

[0005] The jet engine has a fan casing at the front surrounding an annular fan duct and a smaller center casing towards the rear which encloses the core of the jet engine.

[0006] The front engine attachment is interposed between the front end of the rigid structure and the front upper part of the central housing, and the rear engine attachment is interposed between the rigid structure and the rear upper part of the central housing. The device for reacting the thrust generated by the jet engine comprises two rods arranged on either side of a median vertical plane of the jet engine, articulated on the one hand to the central housing and on the other hand to a single diffuser fastened to the rigid structure. The device for reacting thrust formed by the two rods and the diffuser is designed to react all or most of the forces directed along the longitudinal axis X of the jet engine.

[0007] The front engine attachment has a rod on each side of the pylon, each rod being fastened in an articulated manner with one end to the pylon and in an articulated manner with the other end to the center housing. One of the rods is fastened to the pylon via two connection points and to the center housing via one connection point, and the second rod is fastened to the pylon via one connection point and to the center housing via one connection point.

[0008] Although such a structure is satisfactory, it is desirable to find an arrangement which allows saving space, in order to reduce weight and improve the aerodynamics of the aircraft. Summary of the invention

[0009] An object of the present invention is to propose a propulsion assembly comprising a jet engine, a pylon and an attachment device for attaching the jet engine below the pylon.

[0010] To this end, a propulsion assembly for an aircraft is proposed, the propulsion assembly having:

[0011] - a jet engine having a fan case and a center case around a longitudinal axis and having a vertical median plane passing through the longitudinal axis;

[0012] - an attachment pylon having a rigid structure in the form of a box having a front wall and an upper spar extending forwardly relative to the front wall;

[0013] a front engine attachment part, which is fixed between the upper area of ​​the central housing and the lower end of the front wall, and

[0014] - A complementary front engine attachment fixed between the upper area of ​​the fan case and the front end of the upper spar.

[0015] With this arrangement, the size of the attachment is reduced.

[0016] Advantageously, the propulsion assembly comprises a rod secured between the upper spar and the front wall.

[0017] Advantageously, the front engine attachment comprises a pair of first rods on each side of the vertical median plane, wherein a first end of each first rod is hingedly mounted on the lower end of the front wall, and wherein a second end of each first rod is hingedly mounted on the upper region of the central housing.

[0018] Advantageously, the second end of the first rod is closer to the vertical mid-plane than the first end.

[0019] Advantageously, the propulsion assembly comprises, for each first rod, a second rod, a first end of which is hingedly mounted on the lower end of the front wall and a second end of which is hingedly mounted on the upper zone of the central housing.

[0020] Advantageously, the first end of the second rod is closer to the vertical mid-plane than the second end.

[0021] Advantageously, the complementary front engine attachment comprises a lever hingedly mounted at a vertical mid-plane on the front end of the upper spar and comprising ends on each side of the vertical mid-plane hingedly mounted on the upper region of the fan casing, each articulation being at least a rotation about an axis parallel to the longitudinal axis.

[0022] Advantageously, the complementary front engine attachment comprises a plate assembly hingedly mounted at a vertical mid-plane on the front end of the upper spar and comprising, on each side of the vertical mid-plane, an end hingedly mounted on the upper region of the fan casing, each articulation being at least a rotation about an axis parallel to the longitudinal axis.

[0023] The invention also proposes an aircraft having a wing and a propulsion assembly according to one of the previous variants, wherein a rigid structure is fastened under the wing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features of the present invention will become more apparent upon reading the following description of an exemplary embodiment, which description is given with reference to the accompanying drawings, in which:

[0025] Figure 1 is a side view of an aircraft according to the present invention;

[0026] Figure 2 is a schematic diagram of a propulsion assembly according to the present invention;

[0027] Figure 3 is a perspective view of a front engine attachment according to the present invention;

[0028] Figure 4 yes Figure 3 A detailed perspective view of the front engine attachment;

[0029] Figure 5 is a perspective view of an example of a complementary front engine attachment for use in a propulsion assembly according to the present invention;

[0030] Figure 6 yes Figure 5 an exploded view of the complementary front engine attachment;

[0031] Figure 7 is a perspective view of an example of another complementary front engine attachment for use in a propulsion assembly according to the present invention; and

[0032] Figure 8 yes Figure 7 Exploded view of the complementary front engine attachment. DETAILED DESCRIPTION

[0033] Figure 1 An aircraft 50 is shown having a fuselage 51 and wings 52 on each side of the fuselage 51. At least one propulsion assembly 100 is fastened under each wing 52 and it comprises a jet engine 102 and an attachment pylon 104.

[0034] By convention, X represents the longitudinal axis of the propulsion assembly 100, which corresponds to the longitudinal axis X of the jet engine 102. In addition, Y represents the lateral axis of the propulsion assembly 100, which corresponds to the transverse axis of the jet engine 102, which axis is horizontal when the aircraft is on the ground, and Z represents the vertical axis or vertical height of the propulsion assembly, which corresponds to the vertical axis of the jet engine 102, which axis is vertical when the aircraft is on the ground, and these three axes X, Y and Z are orthogonal to each other.

[0035] Furthermore, the terms "front" and "rear" are considered relative to the forward direction of movement of the aircraft when the jet engine 102 is in operation, which direction is schematically indicated by arrow 107. The jet engine 102 also has a vertical median plane P(XZ) passing through the longitudinal axis X and the vertical axis Z.

[0036] The jet engine 102 has at the front a fan casing 102a surrounding an annular fan duct in which the fan rotates, and at the rear of the fan casing 102a a center casing 102b of smaller dimensions enclosing the core of the jet engine 102. The fan casing 102a and the center casing 102b surround a longitudinal axis X.

[0037] The propulsion assembly 100 also has a nacelle 102a in which the jet engine 102 is mounted.

[0038] Figure 2 A propulsion assembly 100 is shown having a jet engine 102 and an attachment pylon 104 via which the jet engine 102 is fastened to the wing 52. The attachment pylon 104 is shown here by its rigid structure 106, also called primary structure, which is fastened below the wing 52.

[0039] The rigid structure 106 extends between the front and rear ends along the longitudinal axis X and takes the form of a box having a lower spar 106a, an upper spar 106b, two lateral walls 106c and a front wall 106d, which are fixed together to realize the rigid structure 106. The front wall 106d is oriented towards the front of the aircraft 50. The lateral walls 106c are arranged on each side of the vertical median plane P. The upper spar 106b is above the lateral walls 106c, while the lower spar 106a is below the lateral walls 106.

[0040] The upper spar 106b extends forwardly relative to the front wall 106d, which means that the upper spar 106b has a front end in the forward direction F away from the front wall 106d.

[0041] In this embodiment, the propulsion assembly 100 comprises a reaction device 170 for reacting the thrust generated by the jet engine 102. Here, the reaction device 170 comprises two reaction rods 170a, which are arranged on either side of the median plane P and are hinged on the one hand at the front to the central housing 102b and on the other hand at the rear to the rigid structure 106, for example to the lower spar 106a, thanks to appropriate fittings, which are not described in detail since they are not part of the invention and which a person skilled in the art will be able to implement as known in the art.

[0042] In this embodiment, the propulsion assembly 100 also includes a rear attachment 180 between the rigid structure 106 and the rear upper portion of the center shell 102b, in this case, between the lower spar 106a and the rear upper portion of the center shell 102b. Since the rear attachment 180 is not part of the present invention, the rear attachment 180 is not described in detail, and a person skilled in the art will be able to implement a prior art rear attachment.

[0043] In the present invention, propulsion assembly 100 includes a front engine attachment 153 secured between upper region 105 of center housing 102b and a lower end of front wall 106d.

[0044] At the same time, the propulsion assembly 100 includes a complementary front engine attachment 152 secured between the upper region 103 of the fan case 102a and the forward end of the upper spar 106b.

[0045] With this arrangement, the size of the attachment is reduced and it allows to optimize the aerodynamics by reducing the size of the fairing of the nacelle.

[0046] According to a particular arrangement of the invention, the front engine attachment 153 reacts both lateral loads (parallel to the lateral axis Y) and vertical loads (parallel to the vertical axis Z), whereas the complementary front engine attachment 152 reacts only lateral loads (parallel to the lateral axis Y).

[0047] Furthermore, due to the side loads acting on the fan case 102a and the side loads acting on the center case 102b, the axial moment Mx is maintained by the front engine attachment 153 and the complementary front engine attachment 152. The load transfer from the jet engine 102 to the attachment pylon 104 with this engine mounting concept is balanced.

[0048] In this embodiment, in order to strengthen the upper spar 106b, the propulsion assembly 100 includes a main rod 156 fixed between the upper spar 106 and the front wall 106d. Each end of the main rod 156 is respectively mounted to the upper spar 106b and the front wall 106d in a hinged manner.

[0049] In one example of the present invention, each end of the main rod 156 is fixed by a clamp. For example, the end of the main rod 156 is a male clamp, which is inserted into a female clamp ( Figure 8 ) and is maintained by an axis perpendicular to the vertical median plane P.

[0050] Figure 3 and 4 A front engine attachment 153 according to the present invention is shown.

[0051] The front engine attachment 153 comprises a pair of first rods 352a-b on each side of the vertical median plane P, which means that there is a pair of first rods 352a on the port side and a pair of first rods 352b on the starboard side.

[0052] For each of the first rods 352a-b, a first end is hingedly mounted on the lower end of the front wall 106d, and a second end is hingedly mounted on the upper area 105 of the central housing 102b.

[0053] Each first rod 352a-b is entirely in a plane perpendicular to the longitudinal axis X, and each end of each first rod 352a-b is attached by a pivot link, the rotation axis of which is entirely parallel to the longitudinal axis X.

[0054] To this end, each end of each first rod 352a-b has a first hinge hole 355, and for each pair of first rods 352a-b, the lower end of the front wall 106d and the upper area 105 of the central housing 102b have a second hinge hole 357. For each pair of first rods 352a-b, the propulsion assembly 100 includes a hinge shaft 359, which is inserted into the corresponding second hinge hole 357 of the front wall 106d or the central housing 102b and into the first hinge hole 355 of the pair of first rods 352a-b.

[0055] In this embodiment, in order to reduce interface loads, the second ends of the first rods 352a-b are closer to the vertical mid-plane P than the first ends. This means that the first rods 352a-b are oriented toward the longitudinal axis X from top to bottom.

[0056] For safety reasons, the propulsion assembly 100 comprises, for each first rod 352a-b, a second rod 354a-b, the first end of which is hingedly mounted on the lower end of the front wall 106d and the second end of which is hingedly mounted on the upper area 105 of the central housing 102b. The second rods 354a-b are also mounted by means of a swivel link and are here mounted on the same hinge axis 359 via appropriate swivel holes 361 in the second rod 354. Each second rod 355a-b is also entirely in a plane perpendicular to the longitudinal axis X, and each end of each second rod 354a-b is attached by means of a pivot link, the axis of rotation of which is entirely parallel to the longitudinal axis X.

[0057] The second rod 354a-b is a waiting fail-safe element. This means that in normal use, the main force path is defined by the first rod 352a-b, and the load is transmitted through this main force path. In the event of a failure of the main force path, the second rod 354a-b is activated, which means that a waiting fail-safe articulation is requested.

[0058] In order to achieve a waiting fail-safe articulation, the diameter of at least one of the rotation holes 361 of each second rod 354a-b is greater than the diameter of the articulation shaft 359. Thus, in normal operation, there is no contact between the second rods 354a-b and the articulation shaft 359, while in the event of a failure, the fan housing 102a will move and the second rods 354a-b will then come into contact with the articulation shaft 359.

[0059] In this embodiment, the first end of the second rod 354a-b is closer to the vertical middle plane P than the second end of the second rod.

[0060] Figure 5 and Figure 6 A complementary front engine attachment 152 is shown for use in the present invention.

[0061] The complementary front engine attachment 152 comprises a rod 154 mounted in an articulated manner at the front end of the upper spar 106b in the vertical mid-plane P. To this end, the front end of the upper spar 106b comprises a front cylindrical piece 157a, the axis of which is in the vertical mid-plane P and parallel to the longitudinal axis X, the rod 157 comprising a front hole 157b into which the front cylindrical piece 157a is inserted in an articulated manner.

[0062] The rod 154 is at least movable in rotation, that is to say about an axis parallel to the longitudinal axis X, about the front cylindrical piece 157 a.

[0063] In this embodiment, the articulation of the rod 157 on the front cylindrical member 157a is a ball joint connection. For this purpose, a spherical bearing 157c is introduced into the front hole 157b, between the front cylindrical member 157a and the rod 154. The main articulation is a rotation around the front cylindrical member 157a while performing a small rotation around another axis.

[0064] On each side of the vertical median plane P, the rod 154 comprises an end 154a-b hingedly mounted on the upper zone 103 of the fan casing 102a. The two ends 154a-b are symmetrical relative to the vertical median plane P.

[0065] To this end, for each end 154a-b of the rod 154, a female clamping piece 159a-b is fixed to the upper area 103 of the fan housing 102a, while the said end 154a-b of the rod 154 is a male clamping piece, which is hingedly mounted in the said female clamping piece 159a-b and is maintained by a hinge axis 161a-b inserted into the hinge hole of the end 154a-b and the hinge hole of the female clamping piece 159a-b, which is parallel to the longitudinal axis X.

[0066] As previously mentioned, each end portion 154a-b is at least rotatably movable about the corresponding portion.

[0067] In the present embodiment, the articulation of each end 154a-b of the rod 157 on the upper region 103 of the fan housing 102a is a ball joint. For this purpose, a spherical bearing 163a-b is introduced into the articulation hole of each end 154a-b, between the rod 157 and the associated articulation axis 161a-b. The main articulation is a rotation about an axis parallel to the longitudinal axis X, with a small rotation about another axis.

[0068] For safety reasons, the upper spar 106b is made of two superimposed plates 107a-b fixed together, and the front cylindrical element 157a is made of two semi-cylindrical elements, one of which is integral with one plate 107a and the other with the other plate 107b.

[0069] In the same manner, the rod 154 is made of two plates fixed together, each plate comprising a front hole 157b for receiving the front cylindrical member 157a, and each end of each plate comprising an articulation hole for receiving the articulation shaft 161a-b.

[0070] For safety reasons, the articulation of one of the two ends 154a-b is a waiting fail-safe articulation. This means that, in normal use, the main force path is defined by one of the ends 154a-b of the rod 154, through which the load is transmitted. In the event of a failure of the main force path, the second end 154a-b of the rod 154 is enabled, which means that a waiting fail-safe articulation is requested. In order to achieve the waiting fail-safe articulation, the diameter of the relevant articulation axis 161a-b is smaller than the diameter of the hole of the end 154a-b of the rod 154. Therefore, in normal operation, there is no contact between the articulation axis 161a-b and the hole of the end 154a-b, while in the event of a failure, the fan housing 102a will move and the articulation axis 161a-b will then come into contact with the hole of the end 154a-b.

[0071] Figure 7 and Figure 8 Another complementary front engine attachment 152 is shown for use in the present invention.

[0072] The complementary front engine attachment 152 comprises a plate assembly 254 which is hingedly mounted at the front end of the upper spar 106b at the vertical midplane P. To this end, the plate assembly 254 comprises a central hole 254c at the vertical midplane P, through which a central shaft 257 is inserted and fixed to the front end of the upper spar 106. The central shaft 257 is parallel to the vertical axis Z and is fixed in a through hole 257b at the front end of the upper spar 106b. Here, the fixing of the central shaft 257 is achieved by providing a nut 257a screwed onto the central shaft 257 and sandwiching the plate assembly 254 and the upper spar 106b.

[0073] The plate assembly 254 is then at least rotationally movable about an axis of articulation parallel to the vertical axis Z relative to the upper spar 106b. In the present embodiment, the articulation of the plate assembly 254 on the upper spar 106b is a ball joint connection. For this purpose, a spherical bearing 260 is introduced in a through hole 257b between the central shaft 257 and the upper spar 106b. The main articulation is a rotation about a vertical axis parallel to the longitudinal axis X with a small rotation about another axis.

[0074] Furthermore, on each side of the vertical middle plane P, the plate assembly 254 comprises an end 254a-b, which is hingedly mounted on the upper region 103 of the fan housing 102a. The two ends 254a-b are symmetrical with respect to the vertical middle plane P. The articulation of each end 254a-b with the upper region 103 of the fan housing 102a is at least a rotation about an end axis parallel to the vertical axis Z. To this end, each end 254a-b has an articulation hole 259a-b, and the propulsion assembly 100 comprises, for each articulation hole 259a-b, an articulation shaft 261a-b fixed to the upper region 103 of the fan housing 102a, wherein the articulation shaft 261a-b is inserted into said articulation hole 259a-b. Each articulation shaft 261a-b has an axis parallel to the vertical axis Z.

[0075] In the present embodiment, the articulation of the plate assembly 254 on the upper region 103 of the fan housing 102a is a ball joint connection. For this purpose, a spherical bearing 263a-b is introduced in each articulation hole 259a-b between the articulation axis 261a-b and the plate assembly 254. The main articulation is a rotation about a vertical axis parallel to the longitudinal axis X, with a small rotation about another axis.

[0076] For safety reasons, the plate assembly 254 comprises two plates 255a - b which are parallel to one another, wherein each plate 255a - b is hingedly mounted on the upper spar 106b and on the upper region 103 of the fan casing 102a.

[0077] To this end, each plate 255a-b has a central hole 254c at the vertical median plane P and a hinge hole 259a-b on each side of the vertical median plane P. The central holes 254c of the two plates 255a-b are coaxial and, on each end 254a-b, the hinge holes 259a-b of the two plates 255 are coaxial.

[0078] The central shaft 257 is inserted into the two central holes 254c, and each hinge shaft 261a-b is inserted into two corresponding hinge holes 259a-b.

[0079] In this embodiment, the propulsion assembly 100 includes a vise 258 having a first jaw 258 a fixed to the upper region 103 of the fan housing 102 a , and a second jaw 258 b fixed to the first jaw 258 a , here by a fixing screw 265 .

[0080] Each articulation axis 261a-b is integral with the second jaw 258b, the free end of each articulation axis 261 being inserted into an insertion hole 267a-b realized for this purpose in the first jaw 258a, so as to ensure the rigidity of said articulation axis 261a.

[0081] In this embodiment, the plate assembly 254 , here referred to as two plates 255 a - b , is installed and rigidly constrained between the two jaws 258 a - b by tightening the fixing screws 265 .

[0082] Furthermore, the upper spar 106b is mounted between the two plates 255a-b. This means that the central axis 257 sequentially spans the upper plate 255a, the upper spar 106 and the lower plate 255b.

[0083] For safety reasons, the upper spar 106b is made of two stacked plates 107a-b fixed together and here a spherical bearing 260 is arranged between the stacked plates 107a-b, wherein each stacked plate comprises a through hole 257b for the passage of the central shaft 257.

Claims

1. A propulsion assembly (100) for an aircraft (50), the propulsion assembly (100) comprising: - a jet engine (102) having a fan casing (102a) and a center casing (102b) around a longitudinal axis (X) and having a vertical median plane (P) passing through said longitudinal axis (X); - an attachment pylon (104) having a rigid structure (106) in the form of a box having a front wall (106d) and an upper spar (106b) extending forwardly relative to the front wall (106d); - a front engine attachment (153) fixed between the upper region (105) of the central housing (102b) and the lower end of the front wall (106d); and - A complementary front engine attachment (152) fixed between the upper region (103) of the fan case (102a) and the front end of the upper spar (106b).

2. The propulsion assembly (100) according to claim 1, characterized in that The propulsion assembly includes a main rod (156) fixed between the upper spar (106b) and the front wall (106d).

3. The propulsion assembly (100) according to claim 1 or 2, characterized in that: The front engine attachment (153) includes a pair of first rods (352a-b) on each side of the vertical middle plane (P), wherein the first end of each first rod (352a-b) is hingedly mounted on the lower end of the front wall (106d), and wherein the second end of each first rod (352a-b) is hingedly mounted on the upper area (105) of the center shell (102b).

4. The propulsion assembly (100) according to claim 3, characterized in that The second end of the first rod (352a-b) is closer to the vertical mid-plane (P) than the first end.

5. The propulsion assembly (100) according to claim 3 or 4, characterized in that: The propulsion assembly (100) includes a second rod (354a-b) for each first rod (352a-b), wherein the first end of the second rod is hingedly mounted on the lower end of the front wall (106d), and the second end of the second rod is hingedly mounted on the upper area (105) of the central shell (102b).

6. The propulsion assembly (100) according to claim 3, characterized in that The first end of the second rod is closer to the vertical mid-plane (P) than the second end.

7. The propulsion assembly (100) according to any one of claims 3 to 6, characterized in that: The complementary front engine attachment (152) comprises a rod (154) hingedly mounted on the front end of the upper spar (106b) at the vertical mid-plane (P), and the rod (154) comprises ends (154a-b) on each side of the vertical mid-plane (P) hingedly mounted on the upper region (103) of the fan casing (102a), each articulated portion being at least a rotation portion around an axis parallel to the longitudinal axis (X).

8. The propulsion assembly (100) according to any one of claims 3 to 6, characterized in that: The complementary front engine attachment (152) comprises a plate assembly (254) hingedly mounted on the front end of the upper spar (106b) at the vertical mid-plane (P), and the plate assembly (254) comprises ends (254a-b) on each side of the vertical mid-plane (P), the ends being hingedly mounted on the upper region (103) of the fan casing (102a), each hinged portion being at least a rotation portion around an axis parallel to the vertical axis (Z).

9. An aircraft (50) having wings (52) and a propulsion assembly (100) according to any one of the preceding claims, wherein: The rigid structure (106) is secured underneath the wing (52).

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