Propulsion system for aircraft comprising turbojet engine, pylon and engine attachment
By introducing the front ring, rear ring and coupling beam into the turbojet engine attachment and combining the nacelle structure, the problem of insufficient load transmission of turbojet engines under the aircraft wings in the prior art is solved, and more efficient force transmission and structural rigidity.
Patent Information
- Application Number
- CN202410899428.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-06-26
- Filing Date
- 2024-07-05
- Publication Date
- 2025-01-07
AI Technical Summary
The existing structures attached to the under-aircraft wings of the aircraft have insufficient load transmission and are difficult to transmit forces and torque better.
Using engine attachments with front ring, rear ring and coupling beam, the front ring is fixed to the fan housing and hanger by first and second fixing means, the rear ring is fixed to the lower spar and through the connecting rod and lock The beam transmits forces, ensuring that the force is transmitted at 360° and increases rigidity through the nacelle structure.
A more uniform and efficient force transmission is achieved, the rigid connection between the hanger and the turbojet engine is enhanced, and the load transfer capability of the overall structure is improved.
Smart Images
Figure CN119262308A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the general field of attaching a turbojet engine under the wing of an aircraft. In particular, it relates to a propulsion system comprising a turbojet engine, in particular a twin-flow engine, a pylon and a hooking device for hooking the turbojet engine under the pylon. It is also applicable to an aircraft equipped with such a propulsion system. Background Art
[0002] The most advanced propulsion system is attached under the wing of the aircraft. It has a turbojet engine and a pylon, by which the turbojet engine is attached under the wing. The pylon has a rigid structure, also called a primary structure, with a first attachment element for attaching the turbojet engine.
[0003] These first attachment elements consist of a front engine attachment, a rear engine attachment and a device for recovering the thrust generated by the turbojet engine.
[0004] The pylon also has a second attachment element allowing the pylon to be attached to the wing.
[0005] A turbojet engine has, at the front, a fan casing surrounding an annular fan duct and, at the rear, a smaller center casing (also called: core casing) enclosing the engine core.
[0006] The front engine attachment is inserted between the front end of the rigid structure and the front upper part of the core shell, and the rear engine attachment is inserted between the rigid structure and the rear upper part of the same core shell. The device for restoring the thrust generated by the turbojet engine comprises two connecting rods arranged on either side of a median vertical plane of the turbojet engine and articulated on the one hand to the core shell and on the other hand to a single beam attached to the rigid structure. The device for restoring thrust formed by the two connecting rods and the beam is designed to restore all or most of the forces directed in the X longitudinal direction of the turbojet engine.
[0007] The front engine attachment has connecting rods on each side of the pylon, each connecting rod being hinged to the pylon at one end and to the center shell at the other end. One of the connecting rods is fixed to the pylon by two connection points and fastened to the core shell by one connection point, while the second connecting rod is fixed to the pylon by one connection point and to the core shell by one connection point.
[0008] The front engine attachment allows to recover in its plane part of the forces oriented according to the directions Y and Z, as well as the torque Mx. The rear engine attachment has a triangular locking beam, one of the upper ends of which is hinged to the pylon and one of the lower ends to the engine. This triangular locking beam is therefore composed of an upper connection point on the pylon side, located in the middle plane of the pylon below its lower wall, and two lower connection points on the engine side, located on each side of the middle plane of the pylon on the engine housing. This arrangement also makes it possible to recover in its plan part of the efforts oriented according to the directions Y and Z.
[0009] Although such a structure is satisfactory, it is desirable to find an alternative arrangement which would allow, inter alia, a better transmission of loads. Summary of the invention
[0010] One object of the present invention is to propose a propulsion system comprising a turbojet engine, a pylon and an engine attachment for attaching the turbojet engine below the pylon with improved load transfer.
[0011] To this end, a propulsion system for an aircraft is proposed, the propulsion system comprising:
[0012] a turbojet engine extending about a longitudinal axis and having a vertical mid-plane passing through the longitudinal axis, and having a fan casing having a rear face perpendicular to the longitudinal axis;
[0013] - a pylon presenting a rigid structure having a front wall and a lower spar; and
[0014] - an engine attachment comprising a front ring coaxial with the longitudinal axis and comprising first fixing means for fixing the front ring to the rear face of the fan case and second fixing means for fixing the front ring to the front wall of the pylon.
[0015] With this arrangement, the force is transmitted evenly over 360° of the front ring.
[0016] Advantageously, the engine attachment has a rear ring and a connecting beam attached between the front ring and the rear ring, wherein the rear ring is coaxial with the longitudinal axis, arranged to the rear of the front ring and attached to the lower spar.
[0017] Advantageously, the pylon has a first rib fixed in the rigid structure at a fastening portion between the rear ring and the lower spar.
[0018] Advantageously, the front ring comprises an upper half-ring attached to the pylon and a lower half-ring attached to the connecting beam, the rear ring comprises an upper half-ring attached to the pylon and a lower half-ring attached to the connecting beam, and the engine attachment has two connecting rods arranged on either side of the median plane, each connecting rod being hingedly mounted between the two upper half-rings.
[0019] Advantageously, the engine attachment has two rear connecting rods arranged on either side of the median plane, wherein each rear connecting rod is hingedly mounted between the rear ring and the lower spar.
[0020] Advantageously, the pylon has a second rib attached inside the pylon at the fastening portion between the two rear connecting rods and the lower spar.
[0021] Advantageously, the first fixing device has two upper joints and two lower joints, wherein the two upper joints are arranged on either side of the center plane and in the upper part of the front ring, and wherein the two lower joints are arranged on either side of the center plane and in the lower part of the front ring.
[0022] Advantageously, each upper joint forms a pivot connection about an axis parallel to a transverse axis perpendicular to the median plane, and each lower joint forms a pivot connection about an axis parallel to a vertical axis inscribed in the median plane and perpendicular to the longitudinal axis.
[0023] Advantageously, the propulsion system comprises a nacelle in the form of two shells attached to each other and to the rear of the fan casing, behind which the two shells are joined to the front ring.
[0024] Advantageously, each shell has an upper wall, two of which face each other and each constitute a lateral wall of the pylon, and are fastened on each side of the lower spar.
[0025] The invention also proposes an aircraft comprising a wing and a propulsion system according to one of the aforementioned embodiments, the rigid structure of the propulsion system being fixed under the wing. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The features of the present invention will become more apparent upon reading the following description of at least one embodiment, which is produced with reference to the accompanying drawings, in which:
[0027] Figure 1 Shows a side view of an aircraft according to the invention;
[0028] Figure 2 is a perspective view of a propulsion system according to a first embodiment of the present invention;
[0029] Figure 3 yes Figure 2 A detailed cross-sectional view of the propulsion system of FIG. 1 taken along a vertical middle plane P;
[0030] Figure 4 is a perspective view of a propulsion system according to a second embodiment of the present invention;
[0031] Figure 5is a perspective view of a specific nacelle assembly implemented in a propulsion system according to the present invention; and
[0032] Figure 6 It is seen according to arrow VI Figure 5 Detail of a portion of the nacelle assembly. DETAILED DESCRIPTION
[0033] Figure 1 An aircraft 50 is shown, which has a wing 52, below which is mounted a propulsion system 100 according to the invention, comprising a pylon 104 and a turbojet engine 102, which is housed in a nacelle 200. Figure 1 In the illustrated embodiment of the invention, an aircraft 50 has a fuselage 53 with wings 52 fixed to each side of the fuselage 53 .
[0034] By convention, X is the longitudinal direction of the turbine 102, which direction X is parallel to the longitudinal axis of the turbine 102. On the other hand, Y is the transverse axis of the turbojet 102, which is horizontal when the aircraft is on the ground, and Z is the vertical axis 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 “front” and “rear” are considered with respect to the direction of advance of the aircraft 50 during operation of the turbojet engine 102 , this direction being schematically indicated by the arrow F.
[0036] The pylon 104 is generally symmetrical relative to a median vertical plane XZ of the turbojet engine 102 , passing through the longitudinal axis X of the turbojet engine 102 and subsequently referred to as median plane P, to which the transverse axis Y is perpendicular.
[0037] The vertical axis Z is inscribed in the median plane P and is perpendicular to the longitudinal axis X.
[0038] Figure 2 A propulsion system 100 is shown, which includes a turbojet engine 102 and a pylon 104, by which the turbojet engine 102 is attached to the wing 52 ( Figure 2 ). The pylon 104 is represented here by its rigid structure 106 , also called primary structure, carrying an engine attachment 152 which ensures the attachment of the turbojet engine 102 underneath the rigid structure 106 .
[0039] The rigid structure 106 is in the form of a box having a front wall 106a at the front of the rigid structure 106, a lower spar 106b extending below the rigid structure 106, and an upper spar 106e extending to the top of the rigid structure 106. The rigid structure 106 also has two side walls 106c-106d on either side of the median plane P. These various spars and walls are fixed to each other to form the rigid structure 106.
[0040] In order to strengthen it structurally, the rigid structure 106 here has first ribs 172 and second ribs 174, which are fixed to various spars and walls inside the rigid structure 106. The second ribs 174 are located at the back of the first ribs 172. Of course, more ribs are conceivable.
[0041] The rigid structure 106 is fixed to the wing 52 by a fastening system which is not shown because it is outside the scope of the invention and which may take any form known to a person skilled in the art.
[0042] exist Figure 2 In the first embodiment of the present invention shown, the turbojet engine 102 includes, from front to rear, a fan casing 103 and an engine casing 105, wherein the fan of the turbojet engine 102 is installed in the fan casing 103, the engine casing 105 is attached to the rear of the fan casing 103, and other elements of the turbojet engine 102 such as a compression stage, a combustion chamber, a turbine stage and an injection nozzle are accommodated in the engine casing 105.
[0043] The fan housing 103 has a rear portion 103 a perpendicular to the longitudinal axis X and therefore extending in a plane parallel to the plane YZ.
[0044] like Figure 2 As shown, the engine attachment 152 has a front ring 154, which is a structural element, coaxial with the longitudinal axis X and therefore extending in a plane parallel to the plane YZ. The front ring 154 is located at the rear face 103a of the fan housing 103. Therefore, the engine housing 105 is accommodated in the front ring 154.
[0045] The engine attachment 152 has a first fixing device 156a that fixes the front ring 154 to the rear face 103a of the fan housing 103. At least three first fixing devices 156a are distributed around the front ring 154 to ensure that stress is transmitted over 360° of the front ring. Preferably, the first fixing device 156a is provided in the upper part of the front ring 154 and the first fixing device 156a is provided in the lower part of the front ring 154.
[0046] In order to fix the front ring 154 to the front wall 106a of the pylon 104, the engine attachment 152 also has a second fixing means 156b. Here, the second fixing means 156b takes the form of a tray 157, which is attached to the front ring 154 and fixed against the front wall 106a by any suitable fastening means such as screws or welds. The second fixing means 156b here provides a rigid connection between the engine attachment 152 and the pylon 104. The tray 157 can be the front wall 106a of the rigid structure 106. It can be integral with the front ring 154 or be a fixed component.
[0047] Figure 4 A second embodiment is shown in which the second fixing means 156b consists of the front wall 106a extending downwardly to the front ring 154 to be fixed thereto by any suitable means such as fasteners or welds.
[0048] Figure 3 A cutout is shown at the level of the second fixing means 156 b , allowing to see the fixing of the tray 157 to the front ring 154 which presents an L-shaped section on its periphery.
[0049] like Figure 3 As shown, the engine housing 105 may be secured within the front ring 154 .
[0050] exist Figure 2 and Figure 4 In both embodiments shown, the engine attachment 152 also has a rear ring 158, also coaxial with the longitudinal axis X and arranged aft of the front ring 154. The rear ring 158 is attached to the lower spar 106b of the rigid structure 106 by any suitable fastening means such as screws or welds.
[0051] The engine attachment 152 further includes a connecting beam 160 attached between the front ring 154 and the rear ring 158. Here, the connecting beam 160 has a U-shaped profile, and the longitudinal ribs of the connecting beam 160 strengthen the structure of the connecting beam 160.
[0052] With this arrangement, the forces are partially transferred to the rear of the rigid structure 106. The connecting beam 160 is fixed here in the lower part between the two rings 154 and 158 (at 6 o'clock).
[0053] In order to ensure better rigidity at the lower spar 106b, the first rib 172 is fixed at the fixing portion between the rear ring 158 and the lower spar 106b, and is fixed to the rear ring 158 and the lower spar 106b at the same time. The fastening means for fixing the rear ring 158 to the lower spar 106b is also attached to the first rib 172, for example, by sandwiching the lower spar 106b between the first rib 172 and the rear ring 158.
[0054] exist Figure 4 In the embodiment of the invention shown, the front ring 154 is divided by a central horizontal plane, so that the front ring 154 is composed of an upper half ring 154a and a lower half ring 154b, which are joined to each other by any suitable integral means as fasteners.
[0055] The upper half ring 154 a is attached to the pylon 104 and the lower half ring 154 b is attached to the tie beam 160 .
[0056] Similarly, the rear ring 158 is divided by a central horizontal plane such that the rear ring 158 is composed of an upper half ring 158a and a lower half ring 158b which are joined to each other by any suitable integral means as fasteners.
[0057] The upper half ring 158 a is attached to the pylon 104 and the lower half ring 158 b is attached to the tie beam 160 .
[0058] Furthermore, the engine attachment 152 has two connecting rods 162, which are arranged on either side of the median plane P and between the front ring 154 and the rear ring 158. Each connecting rod 162 has a front end hinged on the upper half ring 154a of the front ring 154, and a rear end hinged on the upper half ring 158a of the rear ring 158.
[0059] The two connecting rods 162 extend generally parallel to the longitudinal axis X, and the joint of each connecting rod 162 takes the form of a pivot connection whose axis is generally parallel to the transverse axis Y.
[0060] Mounting the turbojet 102 in the rings 154 and 158 consists in moving the turbojet 102 rearwardly along the longitudinal axis X until the rear face 103 a of the fan casing 103 is brought in the vicinity of the front ring 154 , in order to put the first fixing means 156 a in place.
[0061] In order to further transfer some forces to the back of the rigid structure 106, the engine attachment 152 has two rear connecting rods 164, which are arranged on each side of the middle plane P. Each rear connecting rod 164 is located at the rear of the rear ring 158, and each has a first end hingedly mounted on the rear ring 158 at the 3 o'clock direction and the 9 o'clock direction and a second end hingedly mounted on the lower spar 106b.
[0062] exist Figure 2 In the embodiment of the invention shown, the attachment of the second end is provided by a locking beam 164a attached to the lower spar 106b, each end of the locking beam 164a being attached to the second end of the rear connecting rod 164. Here, the rear connecting rod 164 has an arched shape and a rectangular cross-section.
[0063] exist Figure 4In the embodiment of FIG. 1 , each rear connecting rod 164 is attached to the upper half ring 158 a of the rear ring 158 .
[0064] exist Figure 2 In the illustrated embodiment of the present invention, the hinge of each rear connecting rod 164 at the rear ring 158 is in the form of a pivot connection, whose axis is generally parallel to the transverse axis Y, and the hinge of each rear connecting rod 164 at the lower wing beam 106b is in the form of a pivot connection, whose axis is generally parallel to the vertical axis Z.
[0065] As for the rear ring 158, in order to ensure better rigidity at the lower spar 106b, the second rib 174 is fixed at the fixing portion between the rear connecting rod 164 and the lower spar 106, and is simultaneously fixed to the rear connecting rod 164a and the lower spar 106b.
[0066] In the first embodiment of the present invention proposed here, the first fixing means 156a is in the form of holes and screws (not shown) passing through the front ring 154, and fixes the rear surface portion 103a by sandwiching the rear surface portion 103a with the front ring 154. Figure 2 In the embodiment of the invention shown, there are four first fixing devices 156a, which are symmetrically distributed relative to the middle plane P, but there may also be a different number of at least three.
[0067] This arrangement can also be implemented in the second embodiment of the present invention.
[0068] exist Figure 4 In the second embodiment of the invention shown, the first fixing device 156a has two upper joints 170a and two lower joints 170b. The two upper joints 170a are arranged on each side of the middle plane P and in the upper part of the front ring 154, and in the same way, the two lower joints 170b are arranged on each side of the middle plane P and in the lower part of the front ring 154.
[0069] This arrangement can also be implemented in the first embodiment of the present invention.
[0070] Each joint 170a-170b is in the form of a collet connection, wherein a portion of the collet, here the male portion, is attached to the front ring 154, and wherein a portion of the collet, here the female portion, is attached to the rear face portion 103a.
[0071] Here, each upper joint 170a forms a pivot connection about an axis parallel to the transverse axis Y, and each lower joint 170b forms a pivot connection about an axis parallel to the vertical axis Z.
[0072] The axes of the two upper joints 170a are aligned, and the axes of the two lower joints 170b are parallel.
[0073] Figure 5 and Figure 6 A particular embodiment of the invention is shown in which the propulsion system 100 comprises a nacelle 200 forming a structural element ensuring the transmission of forces from the turbojet engine 102 to the pylon 104 .
[0074] The nacelle 200 is in the form of two shells 200a-200b attached to each other. Each shell 200a-200b has a first portion in the form of a semi-cylinder, and the two shells 200a-200b are combined to form the nacelle 200 that encloses the engine casing 105.
[0075] The nacelle 200 is arranged at the rear of the fan casing 103 , with two outer shells 200 a - 200 b attached to the front ring 154 .
[0076] In the lower part of the nacelle 200 , the two shells 200 a - 200 b are joined at a contact line 200 c , which is here in the median plane P, and the fixing is ensured by all suitable means such as welding points or screw elements.
[0077] exist Figure 5 and Figure 6 In the embodiment of the invention shown, ie in the upper part of the nacelle 200 , each housing 200 a - 200 b has a second portion in the form of an upper wall 202 a - 202 b attached to the first portion.
[0078] The upper walls 202a - 202b face each other, extend on either side of the median plane P, and extend generally parallel to the median plane P, ie vertically.
[0079] Each upper wall 202a-202b forms a lateral wall 106c-106d of the pylon 104, and two upper walls 202a-202b are attached to each side of the lower spar 106b and the upper spar 106e.
[0080] This arrangement allows weight to be increased and is easier to install due to the lower number of components of the nacelle 200. This arrangement also allows the pylon 104 to be completely integrated with the nacelle 200.
[0081] like Figure 6 As shown, the lower spar 106b and the upper spar 106e are secured between the upper walls 202a-202b by any suitable fastening means such as weld points or screw elements.
[0082] As for the lower spar 106 b , it is fixed here via intermediate walls 204 , each of which is attached to the upper walls 202 a - 202 b and extends them downwards. The lower spar 106 b is then fixed between the intermediate walls 204 .
[0083] A door 200 d may also be provided on the nacelle 200 to allow access to the interior of the nacelle 200 .
Claims
1. A propulsion system (100) for an aircraft (50), the propulsion system (100) comprising: - a turbojet engine (102) extending about a longitudinal axis (X) and having a vertical mid-plane (P) passing through said longitudinal axis (X), and having a fan casing (103) having a rear face (103a) perpendicular to said longitudinal axis (X); - a pylon (104) presenting a rigid structure (106) having a front wall (106a) and a lower spar (106b); and - an engine attachment (152), comprising a front ring (154) coaxial with the longitudinal axis (X) and comprising first fixing means (156a) for fixing the front ring (154) to the rear face (103a) of the fan casing (103), and second fixing means (156b) for fixing the front ring (154) to the front wall (106a) of the pylon (104).
2. The propulsion system (100) according to claim 1, characterized in that The engine attachment (152) has a rear ring (158) and a connecting beam (160) attached between the front ring (154) and the rear ring (158), wherein the rear ring (158) is coaxial with the longitudinal axis (X), arranged at the rear of the front ring (154) and attached to the lower spar (106b).
3. The propulsion system (100) according to claim 2, characterized in that The pylon (104) has a first rib (172) fixed within the rigid structure (106) at a fixing portion between the rear ring (158) and the lower spar (106b).
4. The propulsion system (100) according to claim 2 or 3, characterized in that: The front ring (154) comprises an upper half ring (154a) attached to the pylon (104) and a lower half ring (154b) attached to the connecting beam (160), wherein the rear ring (158) comprises an upper half ring (158a) attached to the pylon (104) and a lower half ring (158b) attached to the connecting beam (160), and wherein the engine attachment (152) has two connecting rods (162), which are arranged on each side of the middle plane (P) and are each hingedly mounted between the two upper half rings (154a, 158a).
5. The propulsion system (100) according to any one of claims 1 to 4, characterized in that: The engine attachment (152) has two rear connecting rods (164) arranged on either side of the midplane (P), each rear connecting rod being hingedly mounted between the rear ring (158) and the lower spar (106b).
6. The propulsion system (100) according to claim 5, characterized in that The pylon (104) has a second rib (174) attached inside the pylon (104) at a fixing portion between the two rear connecting rods (164) and the lower spar (106b).
7. The propulsion system (100) according to any one of claims 1 to 6, characterized in that: The first fixing device (156a) has two upper joints (170a) and two lower joints (170b), wherein the two upper joints (170a) are arranged on each side of the middle plane (P) and are located in the upper part of the front ring (154), and wherein the two lower joints (170b) are arranged on each side of the middle plane (P) and are located in the lower part of the front ring (154).
8. The propulsion system (100) according to claim 7, characterized in that Each upper joint (170a) forms a pivot connection around an axis parallel to a transverse axis (Y) perpendicular to the median plane (P), and each lower joint (170b) forms a pivot connection around an axis parallel to a vertical axis (Z) inscribed in the median plane (P) and perpendicular to the longitudinal axis (X).
9. The propulsion system (100) according to any one of claims 1 to 8, characterized in that: The propulsion system comprises a nacelle (200) in the form of two shells (200a-200b) attached to each other and to the rear of the fan casing (103), the two shells (200a-200b) being joined to the front ring (154) at the rear of the fan casing.
10. The propulsion system (100) according to claim 9, characterized in that Each shell (200a-200b) has an upper wall (202a-202b), wherein the two upper walls (202a-202b) face each other and each constitutes a lateral wall (106c-106d) of the pylon (104), and wherein the two upper walls (202a-202b) are fixed on each side of the lower spar (106b).
11. An aircraft (50) comprising a wing (52) and a propulsion system (100) according to any one of the preceding claims, a rigid structure (106) of the propulsion system being fixed underneath the wing (52).