FRONT ENGINE MOUNTING SYSTEM FOR A COMPACT AIRCRAFT ENGINE

Description

TECHNICAL FIELD

[0001] The present invention relates to a front engine mounting system for an aircraft engine where the front engine mounting system is compact, as well as an aircraft comprising at least one such front engine mounting. PREVIOUS STATE OF THE ART

[0002] An aircraft typically has at least one engine, in particular a turbojet. Under each wing and for each engine, the aircraft has an engine pylon which is attached to the wing structure and extends below the wing, and the engine is suspended below the engine pylon.

[0003] The engine is housed in a nacelle and attached to the reactor mast via an engine attachment system comprising a front engine attachment and a rear engine attachment.

[0004] There are many types of front engine mountings that are satisfactory for their current applications. However, the fans of new engines are increasingly larger to improve engine performance, thereby reducing the distance between the nacelle and the ground. Document WO 9311041 A1 describes a turbo-engine combustion engine suspended from a pylon by means of a housing, using front and rear mounting devices. The front mounting device comprises a support element with multiple integral pins, this element being fixed to the lower part of the pylon. The first pin engages in an annular flange of the housing to support the engine in a vertical plane, while the second pin engages directly in the housing to prevent axial and lateral movement of the engine relative to the pylon.Document GB 2119857 A1 describes an engine supported from an aircraft wing by a pylon with a beam extending relatively far forward of the pylon. Rather than being thickened to resist increased bending loads, this beam is supported by a link extending from the pylon to a position near its end. The beam is connected, either directly or via a link, to an annular box-section structure separating the support struts 18 and 28. A pin extending from the beam is housed in a socket in the engine's central casing.

[0005] It is then necessary to define a new arrangement allowing the height of the front engine mount to be reduced in order to move the nacelle away from the ground and consequently bring the nacelle closer to the wing. DESCRIPTION OF THE INVENTION

[0006] One object of the present invention is to propose a front engine attachment system which integrates the reactor mast and the front engine attachment to reduce the overall height.

[0007] To this end, a front engine mounting system is proposed for an aircraft engine, the front engine mounting system having a vertical median plane and comprising: a reactor mast having at the front part, a nose having a male clevis and a cylindrical stud around a vertical axis and intended to be mounted movably through an annular linear link around the vertical axis relative to a front engine casing, two connecting rods intended to be fixed to the front casing by a second ball joint around a second axis perpendicular to the median plane, the two connecting rods being arranged on either side of the male clevis, and a first shaft perpendicular to the median plane and making a first ball joint of the connecting rods with the male clevis around a first axis, where the first axis and the second axis are in the same vertical plane perpendicular to the median plane.

[0008] Such a forward engine attachment system has a reduced vertical footprint because the forward engine attachment is integrated into the reactor mast.

[0009] Advantageously, the first axis is positioned behind the vertical axis.

[0010] Advantageously, each connecting rod consists of two connecting rods joined together.

[0011] Advantageously, the nose consists of two fittings fixed to each other and the cylindrical block consists of two half-cylinders joined on the vertical median plane where each half-cylinder belongs to one of the fittings of the nose.

[0012] Advantageously, the first tree consists of a first peripheral tree which is hollow and a first inner tree which is fitted into the first peripheral tree.

[0013] The invention also proposes an aircraft comprising an engine with a front casing and a front engine attachment system according to one of the variants, where the connecting rods are fixed to the front casing by the second ball joint and where the cylindrical block is mounted movably through the annular linear link around the vertical axis relative to the front casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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: Fig. 1 is a side view of an aircraft according to the invention, Fig. 2 is a perspective view of a front engine mounting system according to the invention, Fig. 3 is a perspective view of a cross-section of the front engine mounting system according to the invention at line III of the Fig. 2 , And Fig. 4 is a perspective view of a cross-section of the front engine mounting system according to the invention at line IV of the Fig. 2 . DETAILED EXPLANATION OF IMPLEMENTATION METHODS

[0015] In the following description, terms relating to a position are taken with reference to an aircraft in a forward position, that is, as it is represented on the Fig. 1 , where arrow F represents the direction of advancement.

[0016] There Fig. 1 shows an aircraft 100 which has an engine 102, in particular a turbojet which is fixed under a reactor mast 104 itself fixed under a wing 106.

[0017] In the following description, and by convention, X is called the longitudinal direction of the engine 102 oriented positively in the direction of forward movement of the aircraft 100, Y is called the transverse direction of the engine 102 which is horizontal when the aircraft 100 is on the ground, and Z is called the vertical direction or vertical height when the aircraft 100 is on the ground, these three directions X, Y and Z being orthogonal to each other.

[0018] The motor 102 generally exhibits a form of revolution around the longitudinal axis X. In the embodiment of the invention presented in the Fig. 1 , aircraft 100 has one engine 102 under each wing 106 of aircraft 100, but it is possible to provide several engines under each wing 106.

[0019] There Fig. 2 shows a forward engine mounting system 150 which is attached to the aircraft structure 100, here the wing structure 106, and extends under the wing 106 and supports the engine 102 and in particular the forward part of the engine 102. Figs. 2 à 4 show different views of the front engine mounting system 150.

[0020] The forward engine attachment system 150 includes the engine pylon 104 attached to the wing structure 106 and a forward engine attachment 160 fixed between the engine pylon 104 and a forward casing 103 integral with the engine 102. The forward engine attachment system 150 includes a vertical midplane XZ.

[0021] Typically, a rear engine attachment is fixed between the reactor mast 104 and a rear part of the engine 102 and it can take any form known to a person skilled in the art.

[0022] The reactor mast 104 takes the form of a box which includes, among other things, at the level of a forward part 163, a nose 110 which has a male clevis 111. As specified below, the male clevis 111 ( Fig. 4 ) is arranged between two connecting rods 162a-b which are arranged on either side of the male clevis 111 and which thus form a female clevis in which the male clevis 111 is mounted freely in rotation around a first axis 10 oriented transversely, that is to say perpendicular to the median plane XZ and therefore horizontally so as to make a ball joint called the first ball joint whose main axis of rotation is the first axis 10 and where the rotations about the other two axes are of reduced amplitudes.

[0023] In the embodiment of the invention presented on the Figs. 2 à 4 , the nose 110 consists of two fittings 109a-b fixed to each other here at the level of the median plane XZ.

[0024] The male clevis 111 is here made up of two walls 110a-b which are parallel to each other and vertical, that is to say parallel to the median plane XZ and therefore perpendicular to the transverse direction Y. The two walls 110a-b are joined at the level of the median plane XZ to form the male clevis 111 and each wall 110a-b constituting the male clevis 111 belongs to one of the fittings 109a-b.

[0025] There Fig. 4 shows a cross-section at the level of the male clevis 111 and the two female clevises 103a-b.

[0026] The reactor mast 104 comprises an upper wall 104a, a lower wall 104b, and two side walls 104c-d. The various walls 104a-d are joined together to form a box-shaped structure with a generally trapezoidal vertical cross-section. The nose cone 110 is attached to the forward section 163 of the reactor mast 104 by any known means, such as welding or bolts. The forward section 163 corresponds to the forward ends of the walls 104a-d.

[0027] The front engine mount 160 comprises the two connecting rods 162a-b fixed to the nose 110 by the male yoke 111, and as specified above, arranged on either side of the male yoke 111 and here symmetrically with respect to the median plane XZ. The first ball joint connection of the connecting rods 162a-b with the male yoke 111 is made by a first shaft 165 which is equipped with a nut 170 on which the male yoke 111 is articulated, that is to say here the two walls 110a-b forming the male yoke 111. The first shaft 165 thus passes through the male yoke 111 and the connecting rods 162a-b via bores provided for this purpose. The first shaft 165 is thus perpendicular to the median plane XZ. The first axis 10 constitutes the axis of the first shaft 165.

[0028] Each connecting rod 162a-b is also hinged to the front housing 103 by a second ball joint, the principal axis of rotation of which is a second axis 12 perpendicular to the median plane XZ and therefore horizontal, and where rotations about the other two axes are of reduced amplitude. To this end, the front housing 103 has female yokes 103a-b, each of which is also composed of two parallel and vertical walls, i.e., parallel to the median plane XZ. Two of the walls constituting the female yokes 103a-b are common to both yokes 103a-b, forming a single central wall 103c, namely the middle wall. The female yokes 103a-b are symmetrical with respect to the median plane XZ.

[0029] The connecting rods 162a-b are attached to the female brackets 103a-b by a second shaft 167 which passes through the walls forming the female brackets 103a-b and the connecting rods 162a-b via bores provided for this purpose. The second shaft 167 is thus perpendicular to the median plane XZ. The second axis 12 constitutes the axis of the second shaft 167. The second ball joint connection of the connecting rods 162a-b to the front housing 103 is achieved by the second shaft 167, which is equipped with a nut 172 on which the front housing 103 is articulated, here via the central wall 103c.

[0030] The second axis 12 is aligned vertically with the first axis 10 and below the latter, that is to say that the axis of the second shaft 167 and the axis of the first shaft 165 are in the same vertical plane perpendicular to the longitudinal direction X and therefore to the median plane XZ, or in other words that the main axis of the first ball joint, that is to say the first axis 10, and the main axis of the second ball joint, that is to say the second axis 12, are in the same vertical plane perpendicular to the median plane XZ.

[0031] There Fig. 3 shows a cross-section at the level of an annular linear joint where the translation axis is a vertical axis 20 and which is also called a "spigot joint" 169.

[0032] The nose 110 has a cylindrical stud 502 coaxial with the vertical axis 20, which is therefore oriented vertically and here in the vertical median plane XZ. In the embodiment of the invention presented in the Fig. 3 , the block 502 consists of two half-cylinders joined on the vertical median plane XZ to form the cylindrical block 502 and each half-cylinder belongs to one of the fittings 109a-b of the nose 110.

[0033] The cylindrical block 502 extends downwards and is mounted movably via an annular linear link around the vertical axis 20 relative to the front housing 103. There is therefore a ball joint around a main axis, which is the vertical axis 20, between the cylindrical block 502 and the front housing 103, and thus between the nose 110 and the front housing 103. There is also a sliding joint whose direction is parallel to the vertical axis 20.

[0034] In the embodiment of the invention presented to the Fig. 3The ball joint connection is achieved by fitting a nut 506 mounted around the cylindrical stud 502 on which the front housing 103 is articulated. The nut 506 is between the cylindrical stud 502 and the front housing 103 in which a hole 508 is made to allow the fitting of the nut 506.

[0035] The sliding joint is made between the cylindrical block 502 and the nut 506 which is therefore mounted freely in translation along the cylindrical block 502 parallel to the vertical axis 20. The male clevis 111 is disposed at the rear of the spigot joint 169 with respect to the longitudinal direction X, that is to say that the first axis 10 of the first ball joint is at the rear of the vertical axis 20.

[0036] With such an arrangement, the mast 104 directly incorporates the elements ensuring the attachment of the motor 102 in order to reduce the height required for this attachment.

[0037] When the engine 102 is in operation, forces are generated and they are transmitted to the wing structure through the front casing 103 and the front engine attachment system 150, i.e. through the connecting rods 162a-b, the second shaft 167, the first shaft 165, the spigot link 169 and the reactor mast 104 which form a primary path of forces.

[0038] The forces in Z are thus transmitted through the second ball joint and the first ball joint, that is to say vertically through the connecting rods 162a-b.

[0039] The forces in X and Y are transmitted through the spigot joint 169.

[0040] For safety reasons, the 150 front engine attachment system also includes means that ensure secondary paths of forces that compensate for a failure of the primary path of forces; these means constitute waiting fail-safe means.

[0041] In case of failure, it is necessary to continue to transmit the forces in Z. Thus, according to a particular embodiment of the invention, each connecting rod 162a-b is made up of two connecting rods joined together.

[0042] In the event of failure at the spigot connection 169, it is necessary to continue to transmit the forces in Y. Thus, as specified above, the cylindrical block 502 consists of two half-cylinders joined on the vertical median plane XZ and each half-cylinder belongs to one of the fittings 109a-b of the nose 110. Thus, in the event of failure of one of the half-cylinders, the other remains operational.

[0043] In the event of failure, it is necessary to continue transmitting the forces along the Z-axis. Thus, according to a particular embodiment of the invention, the first shaft 165 consists of a first peripheral shaft 165a, which is cylindrical and hollow, and a first inner shaft 165b, which is fitted into the first peripheral shaft 165a. Such an arrangement makes it possible to compensate for a possible breakage of the first peripheral shaft 165a.

[0044] Similarly, the second shaft 167 consists of a second peripheral shaft 167a, which is cylindrical and hollow, and a second inner shaft 167b, which is fitted into the second peripheral shaft 167a. This arrangement compensates for a possible breakage of the first peripheral shaft 167a.

Claims

1. Front engine attachment system (150) for an engine (102) of an aircraft (100), the front engine attachment system (150) having a vertical median plane (XZ) and having: - an engine pylon (104) having, at a front part, a nose (110) having a male clevis (111) and a cylindrical stud (502) that is cylindrical about a vertical axis (20) and intended to be mounted so as to be able to move, via an annular linear connection, about the vertical axis (20) with respect to a front casing (103) of the engine (102), - two links (162a-b), which are intended to be fastened to the front casing (103) by a second ball-joint connection about a second axis (12) perpendicular to the median plane (XZ), the two links (162a-b) being arranged on either side of the male clevis (111), and - a first shaft (165), which is perpendicular to the median plane (XZ) and establishes a first ball-joint connection of the links (162a-b) to the male clevis (111) about a first axis (10), wherein the first axis (10) and the second axis (12) are in the same vertical plane perpendicular to the median plane (XZ).

2. Front engine attachment system (150) according to Claim 1, characterized in that the first axis (10) is arranged to the rear of the vertical axis (20).

3. Front engine attachment system (150) according to either of Claims 1 and 2, characterized in that each link (162a-b) consists of two adjoining links.

4. Front engine attachment system (150) according to one of Claims 1 to 3, characterized in that the nose (110) consists of two fittings (109a-b) that are fastened to one another, and in that the cylindrical stud (502) consists of two half-cylinders adjoining the vertical median plane (XZ), wherein each half-cylinder belongs to one of the fittings (109a-b) of the nose (110).

5. Front engine attachment system (150) according to one of Claims 1 to 4, characterized in that the first shaft (165) consists of a first peripheral shaft (165a), which is hollow, and of a first inner shaft (165b), which is fitted within the first peripheral shaft (165a).

6. Aircraft (100) having an engine (102) with a front casing (103) and a front engine attachment system (150) according to one of the preceding claims, wherein the links (162a-b) are fastened to the front casing (103) by the second ball-joint connection and wherein the cylindrical stud (502) is mounted so as to be able to move, via the annular linear connection, about the vertical axis (20) with respect to the front casing (103).