Propulsion system for aircraft comprising turbojet engine, pylon and engine attachment

Abstract

The invention relates to a propulsion system (100) comprising: a turbojet engine (102) having a fan housing (102a) and a center housing (102b); a pylon (104) having an upper spar (106b), a front wall (106d) and fittings (172) rigidly fixed to the rigid structure (106) on both sides of a vertical mid-plane (P); a cylindrical pin (174) integrated with the fan housing (102a) and inserted into a hole of the upper spar (106b); a lock beam (200a) having an upper hinge (202) at the vertical mid-plane (P) between the lock beam (200a) and the front wall (106d) and having a lower hinge (204a-b) on both sides of the vertical mid-plane (P) between the lock beam (200a) and the central housing (102b); and two reaction rods (170a) arranged on both sides of the median plane (P), each rod (170a) being hinged at the front end on the central housing (102b) and at the rear end on the fitting (172). In this arrangement, there is no need to have a rear attachment.

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 an engine attachment for fixing 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 attachment elements for attaching the turbojet engine.

[0003] These 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 other attachment elements allowing the pylon to be attached to the wing.

[0005] Although such a structure is satisfactory, it is desirable to find an alternative arrangement which would allow, inter alia, a reduction in weight and a better transmission of loads. Summary of the invention

[0006] One object of the present invention is to propose a propulsion system comprising a turbojet, a pylon and elements for attaching the turbojet below the pylon with improved load transmission.

[0007] To this end, a propulsion system for an aircraft is proposed, the propulsion system comprising:

[0008] - a turbojet engine extending about a longitudinal axis and having a vertical median plane passing through the longitudinal axis and having a fan casing and a center casing located behind the fan casing;

[0009] - a pylon having a rigid structure with an upper spar, a front wall and fittings rigidly fixed to the rigid structure on both sides of a vertical median plane;

[0010] - a cylindrical pin integral with the fan casing, the axis of which is vertical, wherein the cylindrical pin is inserted into a hole in the upper spar;

[0011] - a locking beam, which has an upper hinged portion between the locking beam and the front wall at a vertical middle plane, and a lower hinged portion between the locking beam and the central housing on both sides of the vertical middle plane;

[0012] - Two reaction rods, which are arranged on either side of the median plane, wherein each rod is hinged at the front end to the central housing and at the rear end to the fitting.

[0013] A propulsion system for an aircraft is also proposed, the propulsion system comprising:

[0014] a turbojet engine extending about a longitudinal axis and having a vertical median plane passing through the longitudinal axis and having a fan casing and a center casing located behind the fan casing; and

[0015] - a pylon having a rigid structure with an upper spar, a front wall and fittings rigidly fixed to the rigid structure on both sides of a vertical median plane;

[0016] - a cylindrical pin integral with the fan casing, the axis of which is vertical, wherein the cylindrical pin is inserted into a hole in the upper spar;

[0017] - a locking beam, which has a lower hinged portion between the locking beam and the central housing at a vertical middle plane, and an upper hinged portion between the locking beam and the front wall on both sides of the vertical middle plane; and

[0018] - Two reaction rods, which are arranged on either side of the median plane, wherein each rod is hinged at the front end to the central housing and at the rear end to the fitting.

[0019] With this arrangement, no rear attachment is required between the turbojet engine and the pylon, and the assembly is lighter.

[0020] Advantageously, the hinge of the front end of each lever, the hinge of the cylindrical pin and each upper hinge of the locking beam are located in the same plane oriented from front to back and from top to bottom.

[0021] The invention also proposes an aircraft comprising a wing and a propulsion system according to one of the preceding embodiments, the rigid structure of the propulsion system being fastened beneath the wing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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:

[0023] Figure 1 Shows a side view of an aircraft according to the invention;

[0024] Figure 2 is a side view of a propulsion system according to the present invention;

[0025] Figure 3 is a perspective view of a propulsion system according to the present invention;

[0026] Figure 4 is a perspective view of a first embodiment of a specific shackle attachment; and

[0027] Figure 5 is a perspective view of a second embodiment of a specific shackle attachment. DETAILED DESCRIPTION

[0028] 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 .

[0029] 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.

[0030] 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.

[0031] The pylon 104 and the turbojet 102 are generally symmetrical relative to a vertical median plane XZ of the turbojet 102 , passing through its longitudinal axis X and subsequently referred to as median plane P, to which the transverse axis Y is perpendicular.

[0032] The vertical axis Z is inscribed in the median plane P and is perpendicular to the longitudinal axis X.

[0033] Figure 2 An embodiment of a propulsion system 100 is shown.

[0034] The propulsion system 100 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 the primary structure, carrying an engine attachment 150 which ensures the attachment of the turbojet engine 102 underneath the rigid structure 106 .

[0035] The jet engine 102 has a fan casing 102a at the front, which surrounds an annular fan duct, in which the fan rotates; and a smaller sized center casing 102b behind the fan casing 102a, which encloses the core of the jet engine 102, which includes a compression stage, a combustion chamber, a turbine stage and an injection nozzle. The fan casing 102a and the center casing 102b surround the longitudinal axis X. Figure 1 In the illustrated embodiment, the center housing 102b extends a portion (dashed line) behind the fan housing 102a.

[0036] The rigid structure 106 extends along the longitudinal axis X between the front and rear ends 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 lower end of 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.

[0037] 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.

[0038] The rigid structure 106 is fixed under 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.

[0039] The engine attachment 150 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 arranged on either side of the median plane P, each rod 170a being hinged on the one hand at the front end to the central housing 102b and on the other hand at the rear end to a fitting 172 rigidly fixed to the rigid structure 106, in particular at the lateral lower corners of the rigid structure 106, for example at the lower spar 106a and the lateral wall 106c. The articulation of the rods 170a on the central housing 102b is located at the 3 o'clock and 9 o'clock positions.

[0040] Each end of each rod 170a is attached to the central housing 102b and the fitting 172 respectively by a collet piece. To this end, each end of each rod 170a is a female collet piece, and the male collet piece is formed by a part of the central housing 102b and the fitting 172. Reverse installation is also possible. Each collet piece forms a swivel.

[0041] Here, the axis of the clamping element at the front is perpendicular to the median plane P, and the axis of the clamping element at the rear is oriented from front to rear and from top to bottom, here at approximately 20° to the vertical.

[0042] The engine attachment 150 also comprises, at the vertical midplane P, a cylindrical pin (socket) 174, the axis of which is vertical, i.e. parallel to the vertical axis Z. The cylindrical pin 174 is integral with the fan casing 102a and is inserted in a hole passing through the rigid structure 106, in particular through the upper spar 106b. Movements according to the longitudinal axis X and the transverse axis Y are not possible between the cylindrical pin 174 and the rigid structure 106, while movements according to and about the vertical axis Z are possible between the cylindrical pin 174 and the rigid structure 104, that is to say, the diameter of the cylindrical pin 174 and the diameter of the hole are adjusted.

[0043] The engine accessory 150 further includes a locking beam assembly 180 located between the central housing 102b and the lower end of the front wall 106d, and a first embodiment of the locking beam assembly 180 is shown in FIG. Figure 3 and Figure 4 As shown, the second embodiment Figure 5 shown.

[0044] The buckle assembly 180 includes locking beams 200a-200b having three hinge points. For safety reasons, the locking beams 200a-200b are double locking beams.

[0045] In the first embodiment, an upper hinge portion 202 is provided between the locking beam 200a and the front wall 106d at the vertical middle plane P, and lower hinge portions 204a-204b are provided on both sides of the vertical middle plane P between the locking beam 200a and the central housing 102b.

[0046] In the second embodiment, a lower hinge portion 302 is provided between the locking beam 200b and the central housing 102d at the vertical middle plane P, and upper hinge portions 304a-304b are provided on both sides of the vertical middle plane P between the locking beam 200a and the front wall 106d.

[0047] Each articulation of the lock beam assembly 180 is achieved by an axis (not shown) passing through the lock beams 200a-200b and related elements, namely the central housing 102b or the front wall 106d. Each articulation takes the form of a rotation around an axis, which is also oriented from front to back and from top to bottom.

[0048] Thanks to the engine attachment 150, the assembly is balanced and reacts according to six degrees of freedom. Two degrees of freedom (according to the longitudinal axis X and the transverse axis Y) are managed by the cylindrical pin 174. Two degrees of freedom (according to the transverse axis Y and the vertical axis Z) are managed by the locking beam assembly 180. Two degrees of freedom (according to the longitudinal axis X and the vertical axis Z) are managed by the rod 170a of the reaction device 170.

[0049] At the same time, for the engine attachment 150, the moment Mx is reacted by the upper and lower Y loads and a Z blocking point, the moment My is reacted by the upper and lower X loads and a Z blocking point, and the moment Mz is reacted by two push rods and a Y blocking point. All moments (Mx / My / Mz) are reacted on both the fan case 102a and the center case 102b, eliminating any engine core case bending. This configuration provides advantages for engine core casing (tip clearance), management and improved specific fuel consumption.

[0050] As with the previous arrangement, the propulsion assembly 100 does not include a rear attachment between the rigid structure 106 and the rear upper portion of the center housing 102b. With this arrangement, the weight of the propulsion assembly 100 is reduced.

[0051] In this embodiment, the hinges at the front end of each rod 170a, the hinges of the cylindrical pin 174, and each upper hinge of the locking beam assembly 180 are positioned around the same plane 10, which is also oriented from front to back and from top to bottom, and is generally parallel to the axis of the clamping head at the rear end of the rod 170a. The single plane 10 is generally aligned with the rear plane of the fan housing 102a.

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 (102a) and a center casing (102b) located behind said fan casing (102a); - a pylon (104) having a rigid structure (106) with an upper spar (106b), a front wall (106d) and fittings (172) rigidly fixed to the rigid structure (106) on both sides of a vertical midplane (P); - a cylindrical pin (174) integral with the fan casing (102a), the axis of which is vertical, wherein the cylindrical pin (174) is inserted into a hole in the upper spar (106b); - a locking beam (200a), the locking beam (200a) having an upper hinge portion (202) between the locking beam (200a) and the front wall (106d) at the vertical middle plane (P), and the locking beam (200a) having lower hinge portions (204a-204b) between the locking beam (200a) and the central housing (102b) on both sides of the vertical middle plane (P); and - Two reaction rods (170a) arranged on both sides of the median plane (P), wherein each rod (170a) is hinged at the front end to the central housing (102b) and at the rear end to the accessory (172).

2. A propulsion system (100) of 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 (102a) and a center casing (102b) located behind said fan casing (102a); and - a pylon (104) having a rigid structure (106) with an upper spar (106b), a front wall (106d) and fittings (172) rigidly fixed to the rigid structure (106) on both sides of a vertical midplane (P); - a cylindrical pin (174) integral with the fan casing (102a), the axis of which is vertical, wherein the cylindrical pin (174) is inserted into a hole in the upper spar (106b); - a locking beam (200b), the locking beam (200b) having a lower hinge (302) between the locking beam (200b) and the central housing (102b) at the vertical middle plane (P), and the locking beam (200b) having upper hinges (304a-304b) between the locking beam (200b) and the front wall (106d) on both sides of the vertical middle plane (P); and - Two reaction rods (170a) arranged on both sides of the median plane (P), wherein each rod (170a) is hinged at the front end to the central housing (102b) and at the rear end to the accessory (172).

3. The propulsion system (100) according to claim 1 or 2, characterized in that: The hinge at the front end of each rod (170a), the hinge of the cylindrical pin (174) and each upper hinge of the locking beams (200a-200b) are located in the same plane (10) oriented from front to back and from top to bottom.

4. An aircraft (50) comprising a wing (52) and a propulsion assembly (100) according to any one of the preceding claims, the rigid structure (106) of the propulsion assembly being fastened underneath the wing (52).

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