Aircraft engine assembly with one main rod for engine mounting, and two parallel rods on a cross brace in front of a primary structure of a mast.

Description

TECHNICAL FIELD

[0001] The present application relates to an aircraft propulsion assembly comprising a forward engine mount including a main connecting rod, and two safety connecting rods arranged parallel to said main connecting rod, connected to a forward transverse reinforcement of a primary mast structure and to an aircraft engine. The present invention also relates to an aircraft comprising at least one such propulsion assembly. PREVIOUS STATE OF THE ART

[0002] According to an embodiment visible on the figures 1 et 2 An aircraft 10 has wings 12, and at least one propulsion unit 14 positioned under each of the wings 12. The propulsion unit 14 has a mast 16 fixed under the wing 12 and an engine 18 fixed under the mast 16. More specifically, the mast 16 includes a primary structure 20 which is connected to the engine 18 by an engine attachment 22 and to the wing 12 by a wing attachment 24.

[0003] By convention, X is called the longitudinal direction of the mast 16, this direction X being parallel to the axis of rotation A18 of the engine 18 and to a longitudinal axis of the aircraft 10. On the other hand, Y is called the transverse direction of the mast 16 which is horizontal when the aircraft 10 is on the ground and perpendicular to the axis of rotation A18 of the engine 18, and Z is called the vertical direction or vertical height when the aircraft 10 is on the ground and perpendicular to the axis of rotation A18 of the engine 18, these three directions X, Y and Z being orthogonal to each other.

[0004] On the other hand, the terms "front" and "rear" are to be considered in relation to a direction of forward movement of the aircraft 10 during the operation of the engine 18 (direction of gas flow, the front corresponding to the intake of gases (air) into the engine and the rear corresponding to the exhaust of gases (combustion gases)), this direction being schematically represented by the arrow A. The terms "port" and "starboard" are also to be considered in relation to the direction of forward movement A of the aircraft 10 and in relation to the longitudinal direction X.

[0005] The engine attachment 22 includes a front engine attachment 26, a rear engine attachment 28 and a pair of push rods 30 ensuring the transfer of thrust forces.

[0006] According to a configuration visible on the figure 3 The primary structure 20 of the mast 16 comprises upper and lower stringers 20.1, right and left side panels 20.2, and a plurality of transverse reinforcements 20.3 connecting the upper and lower stringers 20.1 and the right and left side panels 20.2. A forward transverse reinforcement 20.3 is positioned at the front of the primary structure 20 of the mast and extends at least partially over the lower stringer 20.1. This forward transverse reinforcement 20.3 has a bearing surface for attaching the forward engine mount 26, positioned in a horizontal plane, under said forward transverse reinforcement.

[0007] The front engine mount 26 includes: a transverse beam 32 positioned under the primary structure 20, under the front reinforcement, and connected to the primary structure 20 by connecting elements (not visible on the figure 3 ) vertical and to the motor 18 by a safety connecting shaft 36, a first connecting rod 38 connected to the motor 18 by a first motor connecting shaft 40 and to the cross beam 32 by a first beam connecting shaft 42, a second connecting rod 44 connected to the motor 16 by a second motor connecting shaft 46 and to the cross beam 32 by a second beam connecting shaft 48.

[0008] For each beam connection axis 42, 48, the transverse beam 32 includes a clevis having two flanges 32.1, 32.2 between which is positioned the first or second connecting rod 38, 44.

[0009] For each motor connecting shaft 40, 46, the motor housing (not shown on the figure 3 ) includes a yoke having two wings between which is positioned the first or second connecting rod 38, 44.

[0010] For the safety connection axis 36, the transverse beam 32 includes a clevis having a flange 36.1, which is positioned between two flanges of a clevis (not visible on the figure 3 ) of the engine casing.

[0011] Such a front engine attachment 26 has a so-called "fail safe" interface that is separate from the primary load paths. In particular, the connecting rods 38, 44 correspond to the primary load paths and, in the nominal configuration, ensure the transfer of loads, while the safety connecting shaft 36 corresponds to a spare load path, called the safety load path, and, in a degraded configuration of one of the connecting rods 38, 44, or one of the brackets 32.1, 32.2 of the transverse beam 32, or one of the brackets of the engine casing, ensures the transfer of loads.

[0012] With such a front engine mount 26, it is therefore necessary to provide a spare clevis on the engine casing and on the front engine mount (the safety connecting shaft 36). However, the integration of these spare interfaces complicates the design of the engine casing, as well as that of the front engine mounts.

[0013] Furthermore, the distribution of forces can be greatly altered between the nominal and degraded configurations of the front engine mount, which can make the dimensioning of parts complex.

[0014] US2023 / 028982 discloses a prior art assembly between an aircraft pylon and a turbomachine, comprising a forward support configured to connect the forward section of the turbomachine to the forward section of the pylon. The forward support includes suspension brackets connected to the intermediate casing of the turbomachine and the pylon, as well as connecting rods forming articulated links with the suspension brackets. The connecting rods are inserted into the suspension brackets and are traversed by shafts that connect the connecting rods to the turbomachine's suspension brackets and to the pylon's suspension brackets.

[0015] US patent 2003 / 025033 discloses a device for attaching an engine to an aircraft pylon, comprising two fittings assembled together and fixed to the pylon, and two pairs of connecting rods interposed between the two fittings and a portion of the aircraft engine structure. With this prior art attachment device, the integrity of the connection between the pylon and the engine is preserved in the event of failure of any part of the device, without the need for a backup attachment system.

[0016] US2023 / 072158 discloses a prior art forward engine mounting system comprising a jet pylon having a front rib attached to a forward face, a forward engine mounting system comprising a beam attached to the forward end of the front rib, a first connecting rod hinged to the beam by two first connection points and a second connecting rod hinged to the beam by a second connection point, and a forward engine casing. The first connecting rod is hinged to the forward casing by a third connection point and the second connecting rod is hinged to the forward casing by a fifth connection point. Each connection point of a connecting rod to the beam is positioned within a volume that extends forward from the forward face of the jet pylon, such that the forward engine mounting system has a reduced footprint and less drag.

[0017] Therefore, there is a need for a front motor attachment with a so-called "fail safe" interface, which allows limiting the waiting interfaces and better control of the force paths in the structure. DESCRIPTION OF THE INVENTION

[0018] The present invention relates to an aircraft propulsion assembly comprising a primary structure of a mast, an engine, and a front engine attachment linking the primary structure and the engine, the primary structure comprising upper and lower longerons, right and left side panels and a front transverse reinforcement, the front transverse reinforcement comprising, for each right and left side panel, a first clevis projecting from said side panel, and having two first wings, each first wing having a first bore, the engine comprising at least a second clevis having two second wings, each second wing having a second bore.

[0019] According to the invention, the front engine mount comprises: a first connecting rod having third and fourth bores, and being positioned between the first wings of the first clevis of the front transverse reinforcement and between the second wings of the second clevis of the engine, second and third safety connecting rods each having fifth and sixth bores, the first clevis of the front transverse reinforcement and the second clevis of the engine being positioned between the second and third safety connecting rods, a first reinforcement connecting shaft inserted in the first, third and fifth bores, and a first engine connecting shaft inserted in the second, fourth and sixth bores.

[0020] The propulsion assembly according to the invention minimizes the number of pending interfaces by eliminating the clevises on the engine casing and the front engine mount, thus simplifying the design of the engine casing and the front engine mount. This propulsion assembly also maintains the load distribution between the nominal and degraded configurations of the front engine mount, which simplifies component sizing. In particular, the presence of the safety connecting rods ensures the continuity of load transfer under all conditions.

[0021] According to another feature, the engine has a third yoke with two third wings, each third wing having a seventh bore, the second and third safety connecting rods being positioned between the third wings of the engine's third yoke.

[0022] Advantageously, the presence of the third clevis of the motor ensures the continuity of the passage of forces under all conditions (nominal or degraded of the second clevis of the motor).

[0023] According to another characteristic, the second and third safety connecting rods are separated from the third yoke of the engine by a first set.

[0024] Advantageously, this initial clearance allows for manufacturing tolerances, as well as movement due to the articulation of the joint between the front transverse reinforcement and the engine, under degraded conditions. This clearance also allows for rotation of the third engine yoke relative to the second and third connecting rods.

[0025] According to the invention, the first engine connecting shaft is inserted into the sixth bores of the second and third safety connecting rods with a second set of clearance. This second set of clearance allows the second and third safety connecting rods to be kept in place.

[0026] According to another feature, the second and third safety connecting rods are separated from the second engine yoke by a third set.

[0027] Advantageously, this third set of clearances covers manufacturing tolerances, as well as displacements due to the articulation of the joint between the front transverse reinforcement and the engine, under nominal conditions. This clearance also allows for rotation of the second engine yoke relative to the first connecting rod.

[0028] According to another feature, the front engine mount includes, for each first wing of the first clevis of the front transverse reinforcement, a reinforcing ring arranged in the first bore.

[0029] According to another feature, the first reinforcing connecting shaft has an eighth bore, and the propulsion assembly has a second safety reinforcing connecting shaft inserted into the eighth bore of the first reinforcing connecting shaft.

[0030] Advantageously, the presence of a double reinforcement connection axis ensures the continuity of the passage of forces under all conditions (nominal or degraded of the first reinforcement connection axis).

[0031] According to another feature, the first motor link shaft has a ninth bore, and the propulsion assembly has a second safety motor link shaft inserted into the ninth bore of the first motor link shaft.

[0032] Advantageously, the presence of a double motor link axis ensures the continuity of force transmission under all conditions (nominal or degraded of the first motor link axis).

[0033] The present invention also relates to an aircraft comprising at least one propulsion assembly according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other features and advantages will become apparent from the following description of the invention, given by way of example only, with reference to the accompanying drawings, among which: There Fig. 1 is a side view of an aircraft, The Fig. 2 is a side view of an aircraft propulsion assembly without a nacelle, The Fig. 3 is a perspective view of a front engine mount illustrating a prior art embodiment, The Fig. 4 is a perspective view of a front engine mount illustrating one embodiment of the invention, The Fig. 5 is a front view of a front engine mount illustrating one embodiment of the invention, The Fig. 6 is a perspective view of a cross-section of a front engine mount illustrating one embodiment of the invention, The Fig. 7 is a cross-sectional view of a front engine mount illustrating one embodiment of the invention, and The Fig. 8 is a cross-sectional view of a front engine mount illustrating another embodiment of the invention. DETAILED EXPLANATION OF IMPLEMENTATION METHODS

[0035] On the figures 4 à 7 A forward engine mount 60 of a propulsion assembly connecting a primary structure 62 of an aircraft pylon and an engine 64 is shown. In these figures, only a portion of the engine casing 64 and the primary structure 62 are depicted. At least one aircraft propulsion assembly is equipped with such a forward engine mount 60.

[0036] The primary structure 62 includes an upper spar (not shown on the figures 4 à 7 ) and a lower longitudinal member 62.1, a right side panel 66.1 and a left side panel 66.2, as well as a front transverse reinforcement 68. The right and left side panels 66.1, 66.2 extend in planes parallel to the XZ plane. The front transverse reinforcement 68 extends in a plane parallel to the YZ plane. The front transverse reinforcement 68 has, for each right and left side panel 66.1, 66.2, a female bracket 70 projecting from said right or left side panel 66.1, 66.2. Thus, the bracket 70 extends in a plane parallel to the YZ plane, and therefore transversely to the right and left side panels 66.1, 66.2. The clevis 70 has two wings 72, 74, each of which has a bore 76, 78 whose axis is parallel to the longitudinal direction X.

[0037] The engine 64 includes at least one female yoke 80, projecting towards the primary structure 62, and which has two wings 82, 84. The yoke 80 extends along a plane parallel to the YZ plane. Each wing 82, 84 has a bore 86, 88 whose axis is parallel to the longitudinal direction X.

[0038] The front engine attachment 60 has a connecting rod 90, called the main or central rod, which extends in a plane parallel to the YZ plane, and which has a first bore 92 at its first end 90.1 and a second bore 94 at its second end 90.2. The bores 92, 94 extend along an axis parallel to the longitudinal direction X. The first end 90.1 of the main connecting rod 90 is positioned between the wings 72, 74 of the yoke 70 of the front transverse reinforcement 68 and the second end 90.2 of the main connecting rod 90 is positioned between the wings 82, 84 of the yoke 80 of the engine 64. The yoke 70 of the front transverse reinforcement 68 and the yoke 80 of the engine 64 are therefore substantially aligned, so that the wings 72, 74 of the yoke 70 and the wings 82, 84 of the yoke 80 are arranged on either side of the main connecting rod 90.

[0039] The front engine mount 60 also includes two connecting rods 96, 98, known as safety or lateral connecting rods. Each safety connecting rod 96, 98 extends in a plane parallel to the YZ plane and has a first bore 100, 102 at its first end 96.1, 98.1 and a second bore 104, 106 at its second end 96.2, 98.2. The bores 100, 102, 104, 106 extend along an axis parallel to the longitudinal direction X. The yoke 70, and in particular the wings 72, 74, of the front transverse reinforcement 68 is positioned between the first end 96.1 of the safety connecting rod 96 and the first end 98.1 of the safety connecting rod 98. The yoke 80, and in particular the wings 82 and 84, of the engine 64, is positioned between the second end 96.2 of the safety connecting rod 96 and the second end 98.2 of the safety connecting rod 98. In other words, the safety connecting rods 96 and 98 are arranged on either side of the yoke 70 of the front transverse reinforcement 68 and the yoke 80 of the engine 64.Thus, the clevis 70 of the front transverse reinforcement 68 is positioned between the first ends 96.1, 98.1 of the connecting rods 96, 98 of safety, and the clevis 80 of the engine 64 is positioned between the second ends 96.2, 98.2 of the connecting rods 96, 98 of safety.

[0040] The safety connecting rods 96 and 98, and the main connecting rod 90, are therefore arranged parallel to each other, with the main connecting rod 90 positioned between the safety connecting rods 96 and 98. The main connecting rod 90 has longitudinal (along the longitudinal X direction), transverse (along the transverse Y direction), and vertical (along the vertical Z direction) dimensions greater than the longitudinal, transverse, and vertical dimensions of the safety connecting rods 96 and 98. The safety connecting rods 96 and 98 are essentially identical.

[0041] The front engine mount 60 has a first reinforcing connecting shaft 108, called the main shaft, which has a bore 110 whose axis is parallel to the longitudinal direction X. The first reinforcing connecting shaft 108 extends along an axis parallel to the longitudinal direction X. The first reinforcing connecting shaft 108 is arranged in the bore 100 of the safety connecting rod 96, in the bore 76 of the wing 72 of the clevis 70 of the front transverse reinforcement 68, in the bore 92 of the main connecting rod 90, in the bore 78 of the wing 74 of the clevis 70, and in the bore 104 of the safety connecting rod 98. The bores 100, 76, 92, 78, and 104 are coaxial. Thus, the first reinforcing connecting axis 108 allows the front engine mount 60 to be connected to the front transverse reinforcement 68. The front engine mount 60 has a second reinforcing connecting axis 112 for safety arranged in the bore 110 of the first reinforcing connecting axis 108.Thus, the first reinforcement connecting axis 108 and the second safety reinforcement connecting axis 112 form a double reinforcement connecting axis between the front transverse reinforcement 68 and the front engine attachment 60. The second safety reinforcement connecting axis 112 ensures the continuity of the transmission of forces under all conditions, even in the event of a degraded situation of the first reinforcement connecting axis 108.

[0042] The external diameter (radial dimension in the longitudinal direction X) of the second safety reinforcement connecting axis 112 is substantially equal to the diameter of the bore 110 of the first reinforcement connecting axis 108, so that the safety reinforcement connecting axis 112 is inserted by force into the bore 110 of the main reinforcement connecting axis 108.

[0043] The external diameter of the first reinforcing connecting rod 108 is approximately equal to the bore diameter 100, 104 of the safety connecting rod 96, 98, and to the bore diameter 92 of the main connecting rod 90. Rotation of the main connecting rod 90 or the safety connecting rods 96, 98 around the first reinforcing connecting rod 108 is permitted. The main connecting rod 90 and the safety connecting rods 96, 98 are mounted on the first reinforcing connecting rod 108 with an interference fit.

[0044] The front engine mount 60 comprises, for each wing 72, 74 of the bracket 70 of the front transverse reinforcement 68, a reinforcing ring 120, 122 having a hollow body at least partially positioned in the bore 76, 78 of said wing 72, 74. The external diameter of the body of the reinforcing ring 120, 122 is substantially equal to the diameter of the bore 76, 78 of the wing 72, 74 of the bracket 70 of the front transverse reinforcement 68, so that the reinforcing ring 120, 122 is press-fitted into the bore 76, 78 of the wing 72, 74 of the bracket 70. The external diameter of the first reinforcing connecting shaft 108 is substantially equal to the internal diameter of the body of the reinforcing ring 120, 122.

[0045] The front engine mount 60 has a first engine connecting shaft 114, called the main shaft, which has a bore 116 whose axis is parallel to the longitudinal direction X. The first engine connecting shaft 114 extends along an axis parallel to the longitudinal direction X. The first engine connecting shaft 114 is arranged in the bore 102 of the safety connecting rod 96, in the bore 86 of the wing 82 of the clevis 80 of the engine 64, in the bore 94 of the main connecting rod 90, in the bore 88 of the wing 84 of the clevis 80, and in the bore 106 of the safety connecting rod 98. The bores 102, 86, 94, 88, and 106 are coaxial. Thus, the first motor link axis 114 allows the front motor attachment 60 to be connected to the motor 64.

[0046] The front engine mount 60 includes a second safety engine connection pin 118 arranged in the bore 116 of the first engine connection pin 114. Thus, the first engine connection pin 114 and the second safety engine connection pin 118 form a double reinforcement connection pin between the front transverse reinforcement 68 and the front engine mount 60. The second safety engine connection pin 118 ensures the continuity of force transmission under all conditions, even in degraded situations affecting the first engine connection pin 114.

[0047] The external diameter of the second safety motor connecting shaft 118 is substantially equal to the diameter of the bore 116 of the first motor connecting shaft 114, so that the safety motor connecting shaft 118 is inserted by force into the bore 116 of the main motor connecting shaft 114.

[0048] Thus, the main connecting rod 90 is connected to the engine 64 by the first engine connecting shaft 114 and to the front transverse reinforcement 68 by the first reinforcement connecting shaft 108, the main connecting rod 90 being positioned between the wings 72, 74 of the yoke 70 of the front transverse reinforcement 68 and between the wings 82, 84 of the yoke 80 of the engine 64. The safety connecting rods 96, 98 are connected to the engine 64 by the first engine connecting shaft 114 and to the front transverse reinforcement 68 by the first reinforcement connecting shaft 108, the yoke 70 of the front transverse reinforcement 68 and the yoke 80 of the engine 64 being positioned between the safety connecting rods 96, 98.

[0049] The outer faces 72.1, 74.1 of the clevis 70, that is to say the outer face 72.1 of the wing 72 and the outer face 74.1 of the wing 74 (as opposed to the inner faces 72.2, 74.2 of the wings 72, 74 which are opposite each other), are substantially aligned, along the longitudinal direction X, with the outer faces 82.1, 84.1 of the clevis 80, that is to say the outer face 82.1 of the wing 82 and the outer face 84.1 of the wing 84 (as opposed to the inner faces 82.2, 84.2 of the wings 82, 84 which are opposite each other). The longitudinal dimension of the wings 72, 74 of the clevis 70 of the front transverse reinforcement 68 is less than the longitudinal dimension of the wings 82, 84 of the clevis 80 of the engine 64. Thus, the distance along the longitudinal direction X between the wings 72, 74 of the clevis 70 (distance between the inner faces 72.2, 74.2) is greater than the distance between the wings 82, 84 of the clevis 80 (distance between the inner faces 82.2, 84.2).

[0050] At the second end 90.2 of the main connecting rod 90, there is no play between the main connecting rod 90 and the wings 82, 84 of the yoke 80 of the engine 64. In other words, the longitudinal dimension of the main connecting rod 90 is substantially equal to the distance along the longitudinal direction X between the wings 82, 84 of the yoke 80 (distance between the inner faces 82.2, 84.2).

[0051] At the first end 90.1 of the main connecting rod 90, a gap E1 is present between the main connecting rod 90 and each inner face 72.2, 74.2 of the wing 72, 74 of the yoke 70 of the front transverse reinforcement 68. The reinforcing ring 120, 122 has a radial protrusion 120.1, 122.1, with a diameter greater than the external diameter of the body of the reinforcing ring 120, 122, which extends from the body of the reinforcing ring 120, 122 between the main connecting rod 90 and the wings 72, 74 of the yoke 70. The longitudinal dimension of the radial protrusion 120.1, 122.1 is substantially equal to the gap E1. Thus, the space E1 between the main connecting rod 90 and the yoke 70 is filled by the radial protrusion 120.1, 122.1 of the reinforcing ring 120, 122.

[0052] For each safety connecting rod 96, 98, at the first end 96.1, 98.1 of the safety connecting rod 96, 98, a gap E2 is present between the safety connecting rod 96, 98 and the outer face 72.1, 74.1 of the wing 72, 74 of the yoke 70 of the front transverse reinforcement 68. The body of the reinforcing ring 120, 122 extends beyond the bore 76, 78 towards the safety connecting rod 96, 98, and specifically into the gap E2. Thus, the gap E2 between the safety connecting rod 96, 98 and the yoke 70 is filled by the body of the reinforcing ring 120, 122.

[0053] For each safety connecting rod 96, 98, at the second end 96.2, 98.2 of the safety connecting rod 96, 98, a clearance J1 is present between the safety connecting rod 96, 98 and the outer face 82.1, 84.1 of the flange 82, 84 of the yoke 80 of the engine 64. The clearance J1 is configured to cover manufacturing tolerances, as well as displacements due to the articulation of the junction between the front transverse reinforcement 68 and the engine 64, under nominal conditions. The clearance J1 is configured to be as small as possible in order to minimize the deflection of the flanges 82, 84 of the yoke 80. The clearance J1 advantageously allows rotation of the yoke 80 of the engine 64 relative to the main connecting rod 90.

[0054] The main connecting rod 90 is mounted on the first engine connecting rod 114 with an interference fit. For each connecting rod 96, 98 (safety rod), at the second end 96.2, 98.2 of the connecting rod 96, 98 (safety rod), a clearance J2 is present between the bore 102, 106 of the connecting rod 96, 98 (safety rod) and the first engine connecting rod 114. In other words, the first engine connecting rod 114 is inserted into the bores 102, 106 of the connecting rods 96, 98 (safety rods) with a clearance J2. The clearance J2 is designed to be filled in case of a degraded configuration. In other words, the connecting rods 96, 98 (safety rods) are mounted on the first reinforcing connecting rod 108 with an interference fit and on the first engine connecting rod 114 with the clearance J2. In case of failure, the connecting rod(s) 96, 98 safety rod(s) or the first engine connecting shaft 114 moves to bring the wall of the bore 100, 104 of the connecting rod 96, 98 safety rod against the first engine connecting shaft 114.

[0055] In its nominal configuration, the forces are transmitted from the yoke 80 of the engine 64 to the main connecting rod 90, then to the yoke 70 of the front transverse reinforcement 68. In its nominal configuration, the safety connecting rods 96 and 98 are "standby" and do not allow the forces to be transferred. This is because the safety connecting rods 96 and 98 are separated from the first engine connecting shaft 114 by the clearance J2, which is not zero.

[0056] In a first degraded configuration, where the main connecting rod 90 is faulty, the forces will be transmitted from the yoke 80 of the engine 64 to the connecting rods 96, 98 of safety, then to the yoke 70 of the front transverse reinforcement 68. The play J2, present in nominal configuration, between the connecting rods 96, 98 of safety and the first connecting shaft of engine 114 is filled in this degraded configuration. Indeed, the main connecting rod 90 being faulty, it no longer allows the transmission of forces towards the front transverse reinforcement 68. The engine 64, which was held to the front transverse reinforcement 68 by means of the clevis 80 of the engine 64, the main connecting rod 90 and the clevis 70 of the front transverse reinforcement 68 in nominal configuration, will now be held to the front transverse reinforcement 68 by means of the clevis 80 of the engine 64, the safety connecting rods 96, 98 and the clevis 70 of the front transverse reinforcement 68 in this degraded configuration.In this degraded configuration, the first engine connecting shaft 114 then rests in the bore 102, 106 of the connecting rod 96, 98 of safety, so that the clearance J2 between the first engine connecting shaft 114 and the connecting rods 96, 98 of safety is zero.

[0057] In a second degraded configuration, where a wing 82 of the yoke 80 of the engine 64 is faulty, the forces are transmitted from the wing 84 of the yoke 80 of the engine 64 to the main connecting rod 90 and to the safety connecting rod 98, then to the yoke 70 of the front transverse reinforcement 68. Similarly, in this degraded configuration, the play J2 is zero.

[0058] In a third degraded configuration, where a wing 72 of the clevis 70 of the front transverse reinforcement 68 is faulty, the forces are transmitted from the clevis 80 of the engine 64 to the main connecting rod 90 and to the safety connecting rod 98, then to the wing 74 of the clevis 70 of the front transverse reinforcement 68. Similarly, in this degraded configuration, the play J2 is zero.

[0059] There figure 8 represents a front engine attachment according to another embodiment.

[0060] According to this embodiment, the motor comprises at least the first female yoke 80, projecting towards the primary structure of the mast, and having two wings 82, 84, and a second female yoke 130, projecting towards the primary structure of the mast, and having two wings 132, 134. The yokes 80, 130 extend along a plane parallel to the YZ plane. The yokes 80, 130 are arranged parallel to each other. Each wing 82, 84, 132, 134 has a bore 86, 88, 136, 138 whose axis is parallel to the longitudinal direction X. The clevis 80 is disposed between the wings 132, 134 of the clevis 130. The bores 86, 88, 136, 138 are coaxial.

[0061] The clevis 130, and in particular the wings 132, 134, of the engine is positioned around the second end 96.2 of the safety connecting rod 96 and the second end 98.2 of the safety connecting rod 98. In other words, the safety connecting rods 96, 98 are arranged between the wings 132, 134 of the engine yoke 130, and around the yoke 80. Thus, the yoke 70 of the front transverse reinforcement is positioned between the first ends 96.1, 98.1 of the safety connecting rods 96, 98, while the second ends 96.2, 98.2 of the safety connecting rods 96, 98 are arranged between the wing 132 of the yoke 130 and the wing 82 of the yoke 80 for the first safety connecting rod 96, and between the wing 134 of the yoke 130 and the wing 84 of the yoke 80 for the second safety connecting rod 98.

[0062] According to this embodiment, the front engine mount 60 comprises, for each wing 72, 74 of the clevis 70 of the front transverse reinforcement, a first reinforcing half-ring 140, 142 including a hollow body at least partially positioned in the bore 76, 78 of said wing 72, 74, from the inner face 72.2, 74.2 of the wing 72, 74, and a second reinforcing half-ring 144, 146 including a hollow body at least partially positioned in the bore 76, 78 of said wing 72, 74, from the outer face 72.1, 74.1 of the wing 72, 74. The first and second reinforcing half-rings 140, 142, 144, 146 thus form a reinforcing ring for each bore 76, 78 of wing 72, 74.The external diameter of the body of each reinforcing half-ring 140, 142, 144, 146 is substantially equal to the diameter of the bore 76, 78 of the wing 72, 74 of the clevis 70 of the front transverse reinforcement 68, so that each reinforcing half-ring 140, 142, 144, 146 is press-fitted into the bore 76, 78 of the wing 72, 74 of the clevis 70. The external diameter of the first reinforcing connecting axis 108 is substantially equal to the internal diameter of the body of each reinforcing half-ring 140, 142, 144, 146.

[0063] According to this embodiment, the front engine mount 60 comprises, for the main connecting rod 90, a reinforcing ring 148 positioned in the bore 92 of said main connecting rod 90. The external dimension of the reinforcing ring 148 is substantially equal to the dimension of the bore 92 of the main connecting rod 90, so that the reinforcing ring 148 is press-fitted into the bore 92 of the main connecting rod 90. The external diameter of the first reinforcing connecting pin 108 is substantially equal to the internal diameter of the reinforcing ring 148.

[0064] According to this embodiment, the front engine mount 60 comprises, for each connecting rod 96, 98, a reinforcing ring 150, 152 positioned in the bore 100, 104 of said connecting rod 96, 98. The external diameter of the reinforcing ring 150, 152 is substantially equal to the diameter of the bore 100, 104 of the connecting rod 96, 98, so that the reinforcing ring 150, 152 is press-fitted into the bore 100, 104 of the connecting rod 96, 98. The external diameter of the first reinforcing connecting pin 108 is substantially equal to the internal diameter of the reinforcing ring 150, 152.

[0065] The reinforcing ring 150 extends beyond the bore 100 of the safety connecting rod 96, along the longitudinal direction X (here towards the flange 72 of the clevis 70), and the reinforcing half-ring 144 extends beyond the bore 76 of the flange 72 of the clevis 70, in a direction opposite to the longitudinal direction X (here towards the safety connecting rod 96). The reinforcing ring 150 and the reinforcing half-ring 144 abut each other, while a gap results between the safety connecting rod 96 and the flange 72 of the clevis 70.

[0066] The reinforcing ring 148 extends beyond the bore 92 of the main connecting rod 90, on either side of the bore 92. The reinforcing half-ring 140 extends beyond the bore 76 of the flange 72 of the yoke 70 in the longitudinal direction X, and the reinforcing half-ring 142 extends beyond the bore 78 of the flange 74 of the yoke 70, in a direction opposite to the longitudinal direction X. The reinforcing ring 148 and the reinforcing half-rings 140 and 142 are abutted against each other, while a gap results between the main connecting rod 90 and the flange 72 and 74 of the yoke 70.

[0067] The reinforcing ring 152 extends beyond the bore 104 of the safety connecting rod 98, in a direction opposite to the longitudinal direction X (here towards the flange 74 of the clevis 70), and the reinforcing half-ring 146 extends beyond the bore 78 of the flange 74 of the clevis 70, along the longitudinal direction X (here towards the safety connecting rod 98). The reinforcing ring 152 and the reinforcing half-ring 146 abut each other, while a gap results between the safety connecting rod 98 and the flange 74 of the clevis 70.

[0068] According to this embodiment, the front engine mount 60 comprises, for each wing 82, 84, 132, 134 of the engine bracket 80, 130, a reinforcing ring 154, 156, 158, 160 positioned in the bore 86, 88, 136, 138 of said wing 82, 84, 132, 134. The external diameter of the reinforcing ring 154, 156, 158, 160 is substantially equal to the diameter of the bore 86, 88, 136, 138 of the wing 72, 74 of the bracket 70 of the front transverse reinforcement 68, so that the reinforcing ring 154, 156, 158, 160 is press-fitted into the bore. 86, 88, 136, 138 of wing 72, 74 of clevis 70. The external diameter of the first connecting axis reinforcement 108 is substantially equal to the internal diameter of the reinforcing ring 154, 156, 158, 160.

[0069] According to this embodiment, the front engine mount 60 comprises, for the main connecting rod 90, a reinforcing ring 162 positioned in the bore 94 of said main connecting rod 90. The external dimension of the reinforcing ring 162 is substantially equal to the dimension of the bore 94 of the main connecting rod 90, so that the reinforcing ring 162 is press-fitted into the bore 94 of the main connecting rod 90. The external diameter of the first reinforcing connecting pin 108 is substantially equal to the internal diameter of the reinforcing ring 162.

[0070] The reinforcing ring 162 extends beyond the bore 94 of the main connecting rod 90, on either side of the bore 94. The reinforcing ring 154 extends beyond the bore 86 of the flange 82 of the yoke 80 in the longitudinal direction X, and the reinforcing ring 156 extends beyond the bore 88 of the flange 84 of the yoke 80, in a direction opposite to the longitudinal direction X. The reinforcing ring 162 and the reinforcing rings 154, 156 are abutted against each other, while a gap results between the main connecting rod 90 and the flange 82, 84 of the yoke 80.

[0071] According to this embodiment, the outer faces 72.1, 74.1 of the yoke 70 are substantially aligned, along the longitudinal direction X, with the outer faces 82.1, 84.1 of the yoke 80; and the inner faces 72.2, 74.2 of the yoke 70 are substantially aligned, along the longitudinal direction X, with the inner faces 82.2, 84.2 of the yoke 80. The longitudinal dimension of the flanges 72, 74 of the yoke 70 of the front transverse reinforcement is substantially equal to the longitudinal dimension of the flanges 82, 84 of the yoke 80 of the engine. Thus, the distance along the longitudinal direction X between the flanges 72, 74 of the yoke 70 is substantially equal to the distance between the flanges 82, 84 of the yoke 80.

[0072] For each safety connecting rod 96, 98, at the second end 96.2, 98.2 of the safety connecting rod 96, 98, a clearance J3 is present between the safety connecting rod 96, 98 and the inner face 132.1, 134.1 of the wing 132, 134 of the yoke 130 of the engine 64. The clearance J3 is configured to accommodate manufacturing tolerances, as well as displacements due to the articulation of the junction between the front transverse reinforcement 68 and the engine 64, under degraded conditions. The clearance J3 is configured to be as small as possible to minimize the deflection of the wings 132, 134 of the yoke 130. The clearance J3 advantageously allows rotation of the yoke 130 of the engine 64 relative to the safety connecting rod 96, 98.

[0073] According to this embodiment, the first connecting shaft of the motor 114 is arranged in the bore 136 of the wing 132 of the yoke 130, in the bore 102 of the safety connecting rod 96, in the bore 86 of the wing 82 of the yoke 80 of the motor 64, in the bore 94 of the main connecting rod 90, in the bore 88 of the wing 84 of the yoke 80, in the bore 106 of the safety connecting rod 98, and in the bore 138 of the wing 134 of the yoke 130.

[0074] According to this embodiment, in the nominal configuration, the forces are transmitted from the engine yoke 80 to the main connecting rod 90, then to the yoke 70 of the front transverse reinforcement. In the nominal configuration, the safety connecting rods 96 and 98 are "standby" and do not allow the forces to be transferred; and the yoke 130 is also "standby" and does not allow the forces to be transferred. According to this embodiment, in a first degraded configuration, where the main connecting rod 90 fails, the forces will be transmitted from the engine yokes 80 and 130 to the safety connecting rods 96 and 98, then to the yoke 70 of the front transverse reinforcement.

[0075] According to this embodiment, in a second degraded configuration, where a wing 82 of the engine yoke 80 is faulty, the forces are transmitted from the wing 84 of the yoke 80 and the wing 134 of the engine yoke 130 to the main connecting rod 90 and the safety connecting rod 98, then to the yoke 70 of the front transverse reinforcement.

[0076] According to this embodiment, in a third degraded configuration, where a wing 72 of the clevis 70 of the front transverse reinforcement is faulty, the forces are transmitted from the clevis 80 and the wing 134 of the clevis 130 of the engine to the main connecting rod 90 and to the safety connecting rod 98, then to the wing 74 of the clevis 70 of the front transverse reinforcement.

[0077] Regardless of the embodiment, a front engine mount according to the invention has a minimal number of safety / standby interfaces. Furthermore, the distribution of forces in this front engine mount, between a nominal configuration and a degraded configuration, is maintained.

Claims

1. Aircraft propulsion assembly comprising a primary structure (62) of a pylon, an engine (64) and a front engine attachment (60) connecting the primary structure and the engine, the primary structure (62) having upper and lower spars (62.1), right-hand (66.1) and left-hand (66.2) lateral panels and a front transverse reinforcement (68), the front transverse reinforcement (68) having, for each right-hand (66.1) and left-hand (66.2) lateral panel, a first clevis (70) protruding relative to said lateral panel and having two first flanges (72, 74), each first flange (72, 74) having a first bore (76, 78), the engine (64) having at least one second clevis (80) having two second flanges (82, 84), each second flange (82, 84) having a second bore (86, 88), the front engine attachment (60) having: - a first rod (90) having third and fourth bores (92, 94) and being positioned between the first flanges (72, 74) of the first clevis (70) of the front transverse reinforcement (68) and between the second flanges (82, 84) of the second clevis (80) of the engine (64), - a first reinforcement connection pin (108) inserted into the first (76, 78) and third (92) bores, and - a first engine connection pin (114) inserted into the second (86, 88) and fourth (94) bores, characterized in that the front engine attachment (60) also has: - second and third safety rods (96, 98), each having fifth and sixth bores (100, 102, 104, 106), the first clevis (70) of the front transverse reinforcement (68) and the second clevis (80) of the engine (64) being positioned between the second and third safety rods (96, 98), in that the first reinforcement connection pin (108) is inserted into the fifth bores (100, 104) of the second and third safety rods (96, 98), and in that the first engine connection pin (114) is inserted into the sixth bores (102, 106) of the second and third safety rods (96, 98) with a second clearance (J2).

2. Propulsion assembly according to Claim 1, wherein the engine (64) also has a third safety clevis (130) having two third flanges (132, 134), each third flange (132, 134) having a seventh bore (136, 138), the second and third safety rods (96, 98) being positioned between the third flanges (132, 134) of the third safety clevis (130) of the engine (64).

3. Propulsion assembly according to the preceding claim, wherein the second and third safety rods (96, 98) are separated from the third safety clevis (130) of the engine (64) by a first clearance (J3).

4. Propulsion assembly according to one of the preceding claims, wherein the second and third safety rods (96, 98) are separated from the second clevis (80) of the engine (64) by a third clearance (J1).

5. Propulsion assembly according to one of the preceding claims, wherein the front engine attachment (60) comprises, for each first flange (72, 74) of the first clevis (70) of the front transverse reinforcement (68), a reinforcing ring (120, 122) arranged in the first bore (92).

6. Propulsion assembly according to one of the preceding claims, wherein the first reinforcement connection pin (108) has an eighth bore (110) and the propulsion assembly has a second safety reinforcement connection pin (112) inserted into the eighth bore (110) of the first reinforcement connection pin (108).

7. Propulsion assembly according to one of the preceding claims, wherein the first engine connection pin (114) has a ninth bore (116) and the propulsion assembly has a second safety engine connection pin (118) inserted into the ninth bore (116) of the first engine connection pin (114).

8. Aircraft (10) comprising at least one propulsion assembly according to one of the preceding claims.