Aircraft turbofan engine having a rotating hinged cowl and a system for deploying the cowl

Abstract

The invention relates to a turbofan engine having a fixed structure, a fan, a fan casing surrounding the fan, an outer nacelle arranged around the fan casing and mounted hinged on the fixed structure, and a deployment system (250) for moving the outer nacelle from a closed position to an open position, and the deployment system has a guide rail (252) fastened around the fan casing, a slider (254) movable along the guide rail (252) and having a shoe (258), an activation system for moving the slider (254) and the shoe (258) in one direction or in the other direction along the guide rail (252) alternately, and an arm (264) having one end mounted hinged on the shoe (258) and the other end mounted hinged on the outer nacelle. Such motorized deployment system makes it possible to save space and mass of the turbofan engine.

Description

TECHNICAL FIELD

[0001] The present invention relates to a turbofan engine for an aircraft, having a rotatingly hinged nacelle and a system for deploying said nacelle, and to an aircraft having at least one such turbofan engine. BACKGROUND

[0002] An aircraft generally has at least one turbofan engine, which has an engine forming a core, around which an engine nacelle is arranged, the engine nacelle having a fixed structure with a fan casing surrounding a fan arranged in front of the engine and a front nacelle around the fan casing, the front nacelle forming an outer aerodynamic surface.

[0003] The engine nacelle also has a rear nacelle, which extends the front nacelle rearward and which substantially supports a thrust reverser system.

[0004] In order to be able to carry out maintenance on the turbofan engine, it is necessary to open the rear nacelle in order to gain access to the interior of the engine nacelle. To do this, the rear nacelle is mounted hingedly on the fixed structure and an actuator is mounted between the rear nacelle and the fixed structure to assist in opening said rear nacelle.

[0005] While such a system is overall satisfactory, there is still a need to seek a more compact and less bulky system and whose mass has a limited impact on the engine performance. SUMMARY

[0006] It is an object of the present invention to propose an aircraft propulsion system having a nacelle hinged on a fixed structure and rotatable by a motorized deployment system.

[0007] To this end, a turbofan engine for an aircraft is proposed, said turbofan engine having a longitudinal axis and having a fixed structure, a fan, a cylindrical fan casing surrounding the fan, at least one outer nacelle arranged around the fan casing and mounted hingedly on the fixed structure, and, for each outer nacelle, a deployment system moving the outer nacelle from a closed position to an open position and vice versa, wherein each deployment system has:

[0008] - a guide rail fixed along a portion of the circumference of the fan casing,

[0009] - a slider movable along the guide rail and having a boot,

[0010] - an activation system moving the slider and the boot alternately in one or the other direction along the guide rail, and

[0011] - an arm, one end of which is hinged to the shoe and the other end of which is hinged to the outer cowling,

[0012] wherein the activation system has, for each slider, a motor fixed with respect to the guide rail, the drive shaft of the motor being equipped with a gear and a rack, the rack being implemented on the slider and engaging the gear.

[0013] Such motorized deployment system makes it possible to save space and mass for the turbofan engine.

[0014] Advantageously, the guide rail is curved about a longitudinal axis.

[0015] Advantageously, the guide rail has a U shape open outwards, the bottom of which is fastened to the fan casing and the slider moves between the U-shaped walls of the guide rail.

[0016] Advantageously, a plurality of rollers is distributed along each wall constituting the "U" of the guide rail, the rollers having a groove on their periphery and being mounted so as to be able to rotate freely about an axis parallel to the longitudinal axis, and the slider has a rib having a shape opposite to that of the groove of the rollers.

[0017] Advantageously, the turbofan engine has two outer cowlings, the two guide rails being extensions of each other in the bottom of the turbofan engine, each slider being in the form of an arc inscribed in a plane perpendicular to the longitudinal axis, and the two planes being at a distance from each other.

[0018] Advantageously, each outer cowling has a fixed cowling hingedly mounted and a mobile cowling, the mobile cowling being behind the fixed cowling and being mounted so as to be able to translate between an advanced position and a retracted position on the fixed cowling.

[0019] Advantageously, the turbofan engine has a cascade fastened to the mobile cowling, in the advanced position, the cascade being housed between the fan casing and the fixed cowling, and the guide rail being between the fan casing and the cascade.

[0020] The invention also proposes an aircraft having at least one turbofan engine according to any one of the variants described above. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above-mentioned characteristics of the invention, as well as other characteristics, will become more apparent upon reading the following description of exemplary embodiments given with reference to the attached drawings wherein:

[0022] Figure 1 is a side view of an aircraft of the invention,

[0023] Figure 2 is a schematic perspective view of a turbofan engine of the invention,

[0024] Figure 3 is a cross-sectional view taken on the axial plane Figure 2 of the turbofan engine of the application in the partially open position,

[0025] Figure 4 is a front view of the turbofan engine of the application in the fully open position,

[0026] Figure 5 is a front view of the turbofan engine of the application in the fully open position,

[0027] Figure 6 is an exploded perspective view of the motorized deployment system of the application,

[0028] Figure 7 is a line drawing of the deployment system shown in Figure 6 and

[0029] Figure 8 is a cross-sectional view taken on the axial plane Figure 7 of the turbofan engine of the application in the partially open position, DETAILED DESCRIPTION

[0030] In the following description, the terms relating to position are given with reference to the direction of forward movement of the aircraft indicated by the arrow F in Figure 1 .

[0031] Figure 1 An aircraft 10 is shown having a fuselage 12, each side of which is fastened with a wing 14 carrying at least one pylon 16, under which a turbofan engine 100 is fastened.

[0032] In the following description, and by convention, X designates the longitudinal axis of the turbofan engine 100, which is parallel to the longitudinal axis of the aircraft 10 and oriented positively towards the front of the aircraft 10; Y designates the transverse axis, which is horizontal when the aircraft 10 is on the ground; and Z designates the vertical axis, the three directions X, Y and Z being mutually orthogonal when the aircraft 10 is on the ground.

[0033] Figure 2 An example of the turbofan engine 100 of the application is shown.

[0034] The turbofan engine 100 has an engine 102, the front of which is mounted with a fan 104, which serves as known for creating an air flow in the turbofan engine 100 from the front towards the rear, the air flow then moving downstream from the fan 104, i.e. partly in the main air duct of the turbofan engine 100, and partly in the secondary air duct 106 of the turbofan engine 100.

[0035] The engine 102 forms a core in which the air of the main air duct circulates.

[0036] The turbofan engine 100 also has an engine nacelle 108 surrounding the engine 102 and the fan 104.

[0037] The engine 102 has a cylindrical fan case 110 around the fan 104, while the engine nacelle 108 has at least one outer cowl 112 around the fan case 110. The fan case 110 forms in part the fixed structure of the engine 102. Conventionally, there are two outer cowls 112.

[0038] In the figures, only the port outer cowl is shown. Figure 2

[0039] Each outer cowl 112 is mounted to hinge to the fixed structure of the turbofan engine 100 via a plurality of hinges 114. The fixed structure of the turbofan engine 100 can for example be the pylon 16.

[0040] In this case, the axis of articulation of the outer cowl 112 is that of the hinges 114, and it is substantially parallel to the longitudinal axis X.

[0041] Figure 2 The turbofan engine 100 is shown in a position in which the outer cowls 112 are closed, while Figure 5 The turbofan engine 100 is shown in a position in which the outer cowls 112 are fully open. Figure 4 The turbofan engine 100 is shown in a position in which the outer cowls 112 are partially open.

[0042] Thus, each outer cowl 112 is capable of rotational movement on the fixed structure between a closed position and an open position, and vice versa. In the closed position, the outer cowl 112 is close to the fan case 110, while in the open position, the outer cowl 112 is at a distance from the fan case 110.

[0043] In the figures, Figure 2 and Figure 3 In the embodiment shown, each outer cowl 112 has a fixed cowl 112a and a mobile cowl 112b mounted to be able to move in translation on the fixed cowl 112a, behind the fixed cowl 112a.

[0044] The articulation between the outer cowl 112 and the fixed structure is achieved between said fixed structure and the fixed cowl 112a in which the hinges 114 are mounted.

[0045] ​The movable shroud 112b is guided on the fixed shroud 112a by any suitable guiding means, such as, for example, a slider, while the movable shroud 112b is moved by any suitable driving means, such as, for example, an actuator or a motor.

[0046] The movable wind shield 112b can be parallel to the longitudinal axis x in the forward position ( Figure 2 ) and retraction position ( Figure 3 It can be translated between )

[0047] In the forward position, the movable shroud 112b is adjacent to the rear of the fixed shroud 112a and the fan housing 110, thereby achieving aerodynamic continuity with the fixed shroud 112a externally and thus externally demarcating the secondary air duct 106 from the fan housing 110.

[0048] In the retracted position, the movable fairing 112b is raised and retracted relative to the fixed fairing 112a and relative to the fan housing 110, thereby opening a window 302 between the secondary air duct 106 and the outside, allowing air from the secondary air duct 106 to be exhausted to the outside. The retracted position corresponds to the thrust reversal position of the turbofan engine 100.

[0049] The turbofan engine 100 has a reversing means, not shown, such as a reversing door, which blocks the secondary air duct 106 behind the window 302, thereby directing the airflow of the secondary air duct 106 through the window 302 toward the outside. The reversing doors can take any form known to those skilled in the art, and they are deployed across the secondary air duct 106 when the movable shrouds 112b are retracted toward the retracted position, and are retracted outside the secondary air duct 106 when the movable shrouds 112b are advanced toward the forward position.

[0050] To better guide airflow through window 302, engine nacelle 108 also has cascades 304, which are fixed to movable shroud 112b and move simultaneously with the latter, thus positioning across window 302 when in the retracted position.

[0051] In the forward position, cascade 304 is housed between fan housing 110 and fixed shroud 112a.

[0052] The turbofan engine 100 has a deployment system 250 for each outer shroud 112, the deployment system being motorized, which moves the outer shroud 112 from a closed position to an open position, and vice versa. Figure 6An exploded view of the deployment system 250 is shown, the deployment system having a rail 252 fastened along a portion of the periphery of the fan casing 110, in this case around the outer surface of the fan casing 110, i.e. between the fan casing 110 and the outer shroud 112, and more particularly in this case between the fan casing 110 and the fixed shroud 112a. More particularly, in the embodiment of the application presented here, the rail 252 is arranged inside the cascade 304, i.e. between the fan casing 110 and the cascade 304, in the advanced position, thus saving space.

[0053] The rail 252 is curved around the longitudinal axis X to conform to the curvature of the fan casing 110.

[0054] Each outer shroud 112 has one rail 252, i.e. one on the port side and one on the starboard side. In this case, the two rails 252 extend from the 6 o'clock position to approximately the 3 o'clock position.

[0055] In the embodiment of the application presented here, the section of the rail 252 is in the form of a U that opens outwards, the bottom of which is fastened to the fan casing 110.

[0056] The deployment system 250 also has a slider 254 mounted so as to be able to move along the rail 252. Due to the shape of the rail 252, the movement of the slider 254 is a rotation around the longitudinal axis X. In the embodiment of the application presented here, the slider 254 moves between the U-shaped walls of the rail 252.

[0057] The slider 254 has a curved-shaped shoe 258 to match the shape of the rail 252.

[0058] The deployment system 250 has an activation system that moves the slider 254 and the shoe 258 alternately in one or the other direction along the rail 252.

[0059] The deployment system 250 also has an arm 264 mounted so as to be articulated at one end on the shoe 258 and at the other end on the outer shroud 112, and more particularly in this case on the fixed shroud 112a. In this case, each articulation of the arm 264 is in the form of a rotation around an axis parallel to the longitudinal axis X.

[0060] Thus, in the embodiment of the application presented here, when the shoe 258 rises along the rail 252, the arm 264 is raised and opens the outer shroud 112; conversely, when the shoe 258 descends along the rail 252, the arm 264 is lowered and closes the shroud 112.

[0061] Such an arrangement makes it possible to save space and mass compared to the systems of the prior art.

[0062] In this case, the shoe 258 is in the form of a U-shaped clamp (pincer), the ends of the arms 264 being mounted in the shoe.

[0063] In Figure 4 to Figure 7 the embodiment of the application presented in the figures, the activation system has, for each slider 254, a motor 260 fixed with respect to the guide rail 252, the drive shaft of the motor being equipped with a gear wheel 262 and a rack 256, the rack being implemented on the slider 254 and engaging with the gear wheel 262. Depending on the direction of rotation of the motor and therefore of the gear wheel 262, the rack 256 and therefore the shoe 258 will move along the guide rail 252 in one direction or the other.

[0064] The rotation of each motor 260 is electrically controlled, for example by means of a switch.

[0065] In this case, the rack 256 has a curved shape to match the shape of the guide rail 252.

[0066] According to another embodiment not shown, the activation system can have motorized reels; for each slider 254, there is a cable, the first end of which is fastened to the slider 254 and the second end of which is wound on a motorized reel; for each cable, there is at least one return pulley, the return pulley being arranged at a distance from the motorized reel, the cable passing through the return pulley, so that the motorized reel is turned in a first direction to wind the cable, each slider 254 being moved in a first direction along the guide rail 252, and the motorized reel is turned in a second direction to unwind the cable, each slider 254 being moved in a second direction along the guide rail 252 under the action of the weight of the outer cowl 112 transmitted by the arms 264.

[0067] Figure 7 and Figure 8 One particular embodiment is shown in which the sliders 254 are guided by the guide rails 252.

[0068] In this embodiment, the two guide rails 252 are extensions of each other in the bottom of the turbofan engine 100, i.e. in this case in the 6 o'clock direction, and depending on their position, each slider 254 will be guided by one or two guide rails 252.

[0069] Each slider 254 is in the form of an arc, the arc being inscribed in a plane perpendicular to the longitudinal axis X, and the two planes being at a distance from each other.

[0070] As Figure 7 shown, the two sliders 254 face each other parallel to the longitudinal axis X over at least a portion of their path of movement. In the particular embodiment of the activation system with the racks 256, each rack 256 is in the form of an arc, the arc being inscribed in a plane perpendicular to the longitudinal axis X, and the two planes being at a distance from each other.

[0071] In this case, the slide 254 is guided by rollers 270 and ribs 272.

[0072] The rollers 270 are distributed along each wall of the U that constitutes the guide rail 252 and are mounted so as to be able to rotate freely about an axis parallel to the longitudinal axis X, i.e. there are rollers 270 arranged in front of the slide 254 and rollers 270 arranged behind the slide 254. Each roller 270 has a groove on its periphery, in this case a V-shaped groove, but other shapes are also conceivable.

[0073] The ribs 272 are realized on the slide 254 and are shaped in such a way as to be the inverse of the grooves of the rollers 270, i.e. in this case an inverted V, so as to cooperate with said rollers 270. Each rib 272 is housed in the respective groove of the rollers 270, thus ensuring the guidance.

[0074] Therefore, each slide 254 has a rib 272 that is oriented forwards or backwards depending on the case, while each shoe 258 has two ribs 272, one oriented forwards and the other oriented backwards.

[0075] Although the above invention is applied more specifically in a turbofan engine having a nacelle capable of translational movement and a mobile cascade fastened to said mobile nacelle, since the deployment system is integrated on the fan casing and under the cascade, the invention is equally applicable without such a nacelle capable of translational movement, or with a cascade that is fixed or even without a cascade.

Claims

1. A turbofan engine (100) for an aircraft (10), the turbofan engine (100) having a longitudinal axis (X) and a fixed structure, a fan (104), a cylindrical fan housing (110) surrounding the fan (104), and at least one outer shroud (112) arranged around the fan housing (110) and mounted as hinged to the fixed structure, and for each of the outer shrouds (112) having a deployment system (250) for moving the outer shroud (112) from a closed position to an open position and vice versa, wherein, Each of the aforementioned deployment systems (250) has: -A guide rail (252) is fastened along a portion of the periphery of the fan housing (110). - A slider (254) capable of moving along the guide rail (252) and having a boot (258), - An activation system that alternately moves the slider (254) and the boot (258) along the guide rail (252) in one or the other direction, and - An arm (264), one end of which is hinged to the boot (258), and the other end of which is hinged to the outer shroud (112). The activation system has a motor (260) fixed relative to the guide rail (252) for each of the sliders (254), and the drive shaft of the motor is equipped with a gear (262) and a rack (256), the rack being implemented on the slider (254) and meshing with the gear (262).

2. The turbofan engine as claimed in claim 1, characterized in that, The guide rail (252) is bent around the longitudinal axis (X).

3. The turbofan engine as described in claim 2, characterized in that, The guide rail (252) has an outwardly open U-shaped cross section, the bottom of which is fastened to the fan housing (110), and the slider (254) moves between the U-shaped walls of the guide rail (252).

4. The turbofan engine (100) as claimed in claim 3, characterized in that, Multiple rollers (270) are distributed along each wall of the U-shape constituting the guide rail (252), the rollers having grooves on their periphery, and the multiple rollers are mounted to be able to rotate freely about an axis parallel to the longitudinal axis (X), and the slider (254) has ribs (272) having a shape opposite to that of the grooves of the rollers (270).

5. The turbofan engine (100) as claimed in claim 3, characterized in that, The turbofan engine (100) has two outer shrouds (112), wherein the two guide rails (252) are extensions of each other in the bottom of the turbofan engine (100), wherein each of the sliders (254) is in the form of an arc, the arc being etched in a plane perpendicular to the longitudinal axis (X), and the two planes are spaced apart from each other.

6. The turbofan engine (100) as claimed in claim 1, characterized in that, Each of the outer hoods (112) has a hinged fixed hood (112a) and a movable hood (112b) that is located behind the fixed hood (112a) and is mounted to be able to translate between a forward position and a retracted position on the fixed hood (112a).

7. The turbofan engine (100) as claimed in claim 6, characterized in that, The turbofan engine has a cascade (304) fixed to a movable shroud (112b), wherein, in the forward position, the cascade (304) is accommodated between the fan housing (110) and the fixed shroud (112a), and the guide rail (252) is between the fan housing (110) and the cascade (304).

8. An aircraft (10) having at least one turbofan engine (100) as claimed in claim 1.

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