Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
  • F02K1/54—Nozzles having means for reversing jet thrust
  • F02K1/64—Reversing fan flow
  • F02K1/70—Reversing fan flow using thrust reverser flaps or doors mounted on the fan housing
  • F02K1/72—Reversing fan flow using thrust reverser flaps or doors mounted on the fan housing the aft end of the fan housing being movable to uncover openings in the fan housing for the reversed flow
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
  • F02K1/06—Varying effective area of jet pipe or nozzle
  • F02K1/09—Varying effective area of jet pipe or nozzle by axially moving an external member, e.g. a shroud
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2270/00—Control
  • F05D2270/60—Control system actuates means
  • F05D2270/62—Electrical actuators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2270/00—Control
  • F05D2270/60—Control system actuates means
  • F05D2270/64—Hydraulic actuators

Definitions

• the present invention relates to a thrust reverser for a turbojet engine nacelle comprising, on the one hand, means for deflecting at least part of an air flow of the turbojet, and on the other hand, at least one mobile cover in translation in a substantially longitudinal direction of the nacelle adapted to pass alternately from a closed position in which it ensures the aerodynamic continuity of the nacelle and covers the deflection means, to an open position in which it opens a passage in the basket and discovers the means of deviation.
• the present invention also relates to a turbojet engine nacelle comprising such a thrust reverser.
• An aircraft is driven by several turbojets each housed in a nacelle also housing a set of ancillary actuators related to its operation and providing various functions when the turbojet engine is in operation or stopped.
• These ancillary actuating devices comprise in particular a mechanical system for actuating thrust reversers.
• a nacelle generally has a tubular structure comprising an air inlet upstream of the turbojet engine, a median section intended to surround a fan of the turbojet engine, a downstream section housing a thrust reverser means and intended to surround the combustion chamber of the turbojet engine. , and is generally terminated by an ejection nozzle whose output is located downstream of the turbojet engine.
• the modern nacelles are intended to house a turbofan engine capable of generating through the blades of the rotating fan a flow of hot air (also called primary flow) from the combustion chamber of the turbojet engine, and a flow of cold air (secondary flow) flowing outside the turbojet through an annular passage, also called vein, formed between a shroud of the turbojet engine and an inner wall of the nacelle. The two air flows are ejected from the turbojet engine from the rear of the nacelle.
• the role of a thrust reverser is, during the landing of an aircraft, to improve the braking capacity thereof by redirecting forward at least a portion of the thrust generated by the turbojet engine.
• the inverter obstructs the vein of the cold flow and directs it towards the front of the nacelle, thereby generating a counter-thrust which is added to the braking of the wheels of the aircraft.
• an inverter comprises movable covers movable between, on the one hand, an extended position in which they open in the nacelle a passage intended for the deflected flow, and on the other hand, a position retraction in which they close this passage.
• These covers can perform a deflection function or simply activation other means of deflection.
• the reorientation of the air flow is carried out by deflection grids, the hood having a simple sliding function aimed at discover or cover these grids, the translation of the movable hood being effected along a longitudinal axis substantially parallel to the axis of the nacelle.
• Additional locking doors activated by the sliding of the cowling, generally allow a closure of the vein downstream of the grids so as to optimize the reorientation of the cold flow.
• the grid inverter is called natural block gate inverter, the sliding cowling naturally block the vein of the cold stream through its shape and the shape of said vein.
• Such a type of inverter is described in the documents FR 2 132 380 and US 4 232 516 for example.
• the sliding cowl belongs to the rear section and has a downstream side forming an ejection nozzle for channeling the ejection of the air flows.
• This nozzle can come in addition to a primary nozzle channeling the hot flow and is then called secondary nozzle.
• a mobile inverter cover according to FR 2 622 929 comprises a downstream part able to be moved alone or with an upstream part to which it can optionally be locked so as to allow, in a first case, a displacement of the whole of the movable cowl during deployment of the inverter, and in a second case, a displacement of the downstream portion alone thus modifying the outlet section of the nozzle.
• a first object of the present invention is to provide a suitable configuration for a nacelle comprising a natural blocking gate inverter installed more particularly but not limited to a turbojet engine with a high dilution ratio.
• a second objective is to propose an alternative to the solution implemented in the document FR 2 622 929.
• the present invention aims to overcome the aforementioned drawbacks and to meet the objectives mentioned, and consists of a thrust reverser for turbojet engine nacelle comprising, on the one hand, deflection means of at least a part of a air flow of the turbojet engine, and secondly, at least one movable cowl in translation in a direction substantially parallel to a longitudinal axis of the nacelle adapted to pass alternately from a closed position in which it ensures the aerodynamic continuity of the nacelle and covers the deflection means, to an open position in which it opens a passage in the nacelle and discovers the deflection means, characterized in that the movable cowl comprises at least one outer portion having a downstream extension forming a nozzle and at least one inner part mounted each movable in translation and connected to at least one actuating means adapted to allow their displacement, independently of one another or together, in a substantially longitudinal direction of the nacelle.
• the movable cowl by dividing the movable cowl into an inner portion and an outer portion movable at least partially independently of each other, it is possible to adjust the relative positions of the outer portion and the inner portion so that to vary the section of the nozzle formed by the movable cowl by varying the length of the internal aerodynamic line of said movable cowl, both when the movable cowl is in the closed position and covers the deflection means, and when the cowl mobile is in the open position. In this way, it is easy to adapt the section of the ejection nozzle formed by the movable hood to the flight conditions in order to maintain an optimum configuration.
• the outer portion may be indifferently animated by a forward movement upstream of the nacelle or retreat downstream of the nacelle relative to the inner portion.
• the outer portion and the inner portion are separated at a hollow of an internal aerodynamic line of the movable cowl. This minimizes the impact of the aerodynamic accident that represents the break between the outer part and the inner part.
• the internal aerodynamic line trough is intended, when the movable cowl is in the closed position, to be situated opposite a hump of a turbojet casing defining, with the internal aerodynamic line of the mobile cowl, a channel inside.
• the mobile cowl is equipped, on the one hand, with means for actuating one of the outer or inner portions, and on the other hand with locking means able to pass, alternatively a locking position in which the outer part is connected to the inner part, to an unlocking position in which the outer part or the inner part connected to the actuating means is able to move independently of the other part.
• the actuating means is connected to the external part.
• the mobile cowl is equipped with means for actuating the external part and with own means for actuating the internal part, able to be activated independently of each other. to allow, on the one hand, a simultaneous movement of the part external and internal part, and secondly, a relative displacement between the outer portion and the inner portion.
• the actuating means comprise cylinders, pneumatic cylinders, electric and / or hydraulic type.
• the actuating means comprise a telescopic jack having a first rod adapted to allow the displacement of the inner portion and a second rod adapted to allow the displacement of the outer portion, the two rods being controllable synchronously or independently. one of the other.
• the actuating means comprise a screw / nut actuation system that can be actuated pneumatically, electrically and / or hydraulically.
• the outer and inner parts are equipped with guide means adapted to cooperate with complementary guide means connected to a fixed part of the nacelle.
• the guide means are rails capable of cooperating with corresponding grooves.
• the rails of the outer part and the inner part are distinct.
• the rail of the external part is integrated in the rail of the inner part.
• the present invention also relates to a turbojet engine nacelle, characterized in that it comprises at least one thrust reverser according to the invention.
• nacelle for turbojet turbofan, preferably at high dilution ratio.
• the thrust reverser is a natural blocking thrust reverser.
• FIG. 1 is a diagrammatic representation in longitudinal section of a nacelle of a high dilution rate turbofan jet engine according to the prior art equipped with a thrust reverser with natural locking gates.
• Figure 2 is a detailed representation of a thrust reverser according to the invention.
• FIG. 3 is a representation of a first variant arrangement of the actuating means of FIG. 3.
• FIG. 4 is a representation of a second alternative arrangement of the actuating means of FIG. 3.
• FIG. 5 is a representation of a third variant arrangement of the actuating means of FIG. 3.
• FIG. 6 is a representation of a fourth arrangement variant of the actuating means of FIG. 3.
• FIG. 7 is a schematic representation of a first embodiment of the means for actuating the moving cowl of the inverter of FIG. 2.
• Figure 8 is a schematic representation of the inverter of Figure 3 in the closed position forming a minimum section ejection nozzle.
• Figure 9 is a schematic representation of the inverter of Figure 3 in the closed position forming a nozzle of maximum section ejection.
• Figure 10 is a schematic representation of the inverter of Figure 3 in the open position forming a nozzle of maximum section ejection.
• Figure 11 is a schematic representation of the inverter of Figure 3 in the open position forming a minimum section ejection nozzle.
• FIG. 12 is a representation of a second embodiment of the actuator means of the inverter of FIG. 2.
• FIG. 13 is a representation of a third embodiment of the actuator means of the inverter of FIG. 2.
• Figure 14 is a schematic representation of the embodiment of Figure 13 in the closed position and forming an ejection nozzle having a minimum section.
• Figure 15 is a schematic representation of the embodiment of Figure 13 in the open position and forming an ejection nozzle having a maximum section.
• FIG. 1 represents a nacelle 1 for a double-flow turbojet engine with a high dilution ratio according to the prior art.
• the nacelle 1 is intended to constitute a tubular housing for a turbofan engine (not shown) with a large dilution ratio and serves to channel the air flows it generates through the blades of a fan (not shown ), namely a flow of hot air passing through a combustion chamber (not shown) of the turbojet, and a cold air flow flowing outside the turbojet engine.
• the nacelle 1 has a structure comprising a front section forming an air inlet 4, a median section 5 surrounding the fan of the turbojet, and a rear section surrounding the turbojet and comprising a thrust reversal system.
• the air inlet 4 has an inner surface 4a for channeling the incoming air and an outer fairing surface 4b.
• the median section 5 comprises, on the one hand, an internal casing 5a surrounding the turbojet fan, and on the other hand, an outer casing fairing structure 5b extending the outer surface 4b of the air inlet section 5.
• the casing 5a is attached to the air intake section 4 that it supports and extends its inner surface 4a.
• the rear section comprises an external structure comprising a thrust reversal system and an internal engine fairing structure 8 defining with the external surface a vein 9 intended for the circulation of a cold stream in the case of a nacelle 1 of turbojet engine as shown here.
• Each thrust reversal system comprises a movable cowl 10 in translation along a substantially longitudinal axis of the nacelle and adapted to pass alternately from a closed position in which it houses deflection grids 11 and ensures the structural continuity of the section. median 5 thus allowing the evacuation of the cold flow through the vein
• the gate reversal system presented here is a natural blocking gate reversal system.
• the internal structure 8 of the rear section has in avai deflection grids 11, a hump 12 sufficiently large to substantially reach the level of the casing 5a of the nacelle 1.
• the inner diameter of the nacelle 1 at the output of the casing 5a of the middle section 5 is substantially equal to the diameter of the internal structure 8 at the hump 12.
• the movable cowl 10 has, on the one hand, an outer surface 13 capable of ensuring the external structural continuity of the nacelle 1 with the outer fairing structure 5b of the casing 5a, and on the other hand, an internal surface 14 capable of ensuring the internal structural continuity of the nacelle 1 with the casing 5a, the inner surface 14 substantially following the curvature of the internal structure 8 so that the vein 9 retains a substantially constant section and therefore has a hollow corresponding to the bump 12 located substantially opposite the latter when the movable cover 10 is in the closed position.
• the movable cowl 10 completely closes the vein 9, the hump 12 bringing the internal structure 8 in close contact with an upstream portion of said movable cowl 10 to the operating game near maneuver.
• the movable cover 10 comprises an outer portion 10a and an inner portion 10b independent of each other, each being movable parallel to a substantially longitudinal axis A of the nacelle.
• the outer portion 10a and the inner portion 10b are separated at the recess of the inner surface 14 so that the inner surface
• the inner surface 14 is performed, upstream of the hollow, by a wall of the inner portion 10b of the movable cowl 10 and downstream of the hollow, by an inner wall of the outer portion 10a, the outer surface 13 being formed by an outer wall of the portion external 10a.
• the inner surface 14 has a minimal aerodynamic crash at break between the outer portion 10a and the inner portion 10b.
• the inner wall of the outer portion 10a has an inward extension 15 of the mobile cover 10, the length of this extension depending on the importance of the desired maximum relative displacement between the outer portion 10a and the outer portion 10b.
• the median structure 5 has, at its interface with the movable cowl 10 of the thrust reverser, a slot 16 intended to receive a longitudinal wall 17 extending the outer wall of the outer portion 10a of the movable cowl over a distance slightly greater than the maximum relative displacement distance of the outer portion 10a relative to the inner portion 10b.
• the length of the longitudinal wall 17 of extension and the depth of the slot 16 depend on the importance of the maximum spacing and approximation between the outer portion 10a and the middle structure 5.
• Figures 3 to 6 show different configurations of the guide external parts 10a and internal 10b.
• each of the outer and inner portions 10a and 10b is equipped with at least one lateral guide rail 18, 19 able to slide inside a corresponding groove 20, 21 formed in a structure 22, preferably a common one, linked directly or indirectly to a fixed structure 23 of the inverter or nacelle 1, such as the median structure 5, by means of a carrier structure 24.
• a preferred arrangement of the guide means is to obtain a substantially balanced positioning between, on the one hand, the axis of the guide rail 18 of the outer portion 10a and the top of the outer wall of said outer portion 10a, and on the other hand, between the axis of the guide rail 19 of the inner portion 10b and the furthest point of the inner portion 10b.
• the shape and arrangement of the guide rails 18, 19 must be chosen so that the difference between said guide rails 18, 19 is as small as possible in order to reduce the dimensions of the aerodynamic appendages 25, 26 to a minimum.
• each external part 10a and internal part 10b of the movable cover 10 may be superposed (FIG. 3), slightly offset (FIG. 4), or else aligned
• Figure 6 Another possible configuration ( Figure 6) may be to arrange the guide rail 18 inside the guide rail 19, which then serves as a groove.
• the guide rail 18 of the outer portion 10a performs a smaller displacement relative to its groove, constituted by the guide rail 19 of the internal structure.
• each of the outer 10a and inner 10b is connected to a cylinder 28, 29, pneumatic, hydraulic or electrical type, and preferably electrical, capable of allowing a longitudinal displacement of the outer portion
• FIG. 7 shows the relative positions of the outer part 10a and the inner part 10b of the movable cowl 10 when the latter is in the closed position, covering the deflection grids 11, and having a section of the usual ejection nozzle .
• the section of the nozzle can be easily modified by independently moving the outer portion 10a and the inner portion 10b through their respective cylinders 28, 29.
• Figure 8 shows a thrust reverser in the closed position forming a reduced section ejection nozzle, the cylinder 28 of the outer portion 10a being retracted to the maximum.
• FIG. 9 represents a thrust reverser in the closed position forming an enlarged section ejection nozzle, the jack 28 of the outer part 10a being deployed to move the outer part 10a relative to the inner part 10b without breaking the aerodynamic line. internal through the extension 15 of the inner wall of the outer portion 10a providing aerodynamic continuity with the inner portion 10b.
• FIG. 10 represents a thrust reverser in open thrust reversal position forming a section ejection nozzle magnified, the outer 10a and inner 10b portions being moved simultaneously from the position shown in FIG. 8.
• FIG. 11 shows a thrust reverser in open thrust reversal position forming a conventional section ejection nozzle.
• the opening of the movable cowl 10 takes place from the position shown in FIG. 8. In this position only the jack 29 of the inner part 10b is fed and moves the inner part 10b to bring it into a position relative to the external part 10a identical to that shown in Figure 6 or the same as that shown in Figure 7, said catching position. Once the catch position is reached, the cylinders 28, 29 of the outer 10a and inner 10b parts are actuated simultaneously to the desired reverse reversing position.
• Such an opening method makes it possible to reduce the length of rectilinear displacement of the jack 28 and consequently to reduce the length of the drive rail, which consequently makes it possible to reduce the length of the aerodynamic fairing appendage 25 by overflow of the basket 1.
• the closure of the movable cowl 10 is reversed in the same way.
• the important thing is to ensure that the opening section obtained between the outer portion 10a and the median section 5 of the nacellei or a fixed structure of the inverter is external or equal to the existing opening section between the part internal 10b and the median section 5 of the nacelle 1 or a fixed structure of the inverter.
• the actuating means comprise a telescopic jack 30 having a first rod 30a connected to the outer portion 10a and a second rod 30b connected to the inner portion 10b.
• this telescopic jack 30 can be hydraulic, pneumatic or electrical, preferably electrical.
• the assembly is completed by locking means 31 of the outer portions 10a (means not shown) and internal 10b.
• the reduction and increase of the section of the ejection nozzle are carried out by means of a hydraulic pressure acting on the sections of the rods 30a, 30b.
• the first rod 30a 1 connected to the outer portion 10a, which is actuated.
• the second rod 30b driving thereafter the inner part 10b of the hood mobile 10 after unlocking the locking means 31 of said inner portion 10b.
• the attachment of the inner portion 10b to the second rod 30b may be performed by means of oblong eyelets 32 disposed on either side of the second rod 30b, so as to reduce the overhang of the point of attachment and avoid any hyperstatic stress in the alignment of the inner portion 10b and the drive points of the outer 10a and inner 10b.
• FIGS. 13 to 15 show a drive system of the outer and inner portions 10a and 10b comprising a mechanical screw or ball screw system connected to the outer portion 10a and a fixed nut 36 connected to a fixed structure of the the inverter or the median structure 5 of the nacelle 1.
• the drive of the outer portion 10a is formed either by a fixed screw on the outer portion 10a or by a fixed nut on the outer portion 10a.
• the driving power can be hydraulic, pneumatic or electric. More specifically, a sheath 37 connected to a fixed structure of the inverter or the center section 5 of the nacelle 1 supports the drive motor nut 36 of the fixed screw 35 connected to the outer portion 10a.
• At least one latch 37 maintains at an attachment point 38 the inner portion 10b in the closed position of the movable cover 10.
• a locking element of the inner portion 10b with the outer portion 10a is maintained in the open position.
• the outer portion 10a can slide independently of the inner portion 10b until a complementary locking means of the outer portion 10a engage with the inner portion 10b.
• the locking element is a rocker 39 articulated at a point 40 of the inner portion 10b adapted to cooperate with a hook 41 terminating the extension 15 of the inner wall of the outer portion 10a.
• the section of the ejection nozzle can be easily reduced by retracting the drive screw 36.
• the increase of the section of the ejection nozzle is done in the same way by unfolding the screw 36 drive until the hook 41 abuts against the inner portion 10b.
• the thrust reverser is opened from the previous position.
• the latch 37 is disengaged to release the inner portion 10b. In doing so, it returns, via a spring 42, the rocker 39 in the locking position behind the hook 41.
• the drive screw 36 is then deployed, driving both the outer portion 10a and the inner portion 10b through the hook 41.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Control Of Turbines (AREA)
• Supercharger (AREA)

Applications Claiming Priority (2)

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• 2006
  • 2006-06-21 FR FR0605512A patent/FR2902839B1/fr not_active Expired - Fee Related
• 2007
  • 2007-05-02 CA CA002654362A patent/CA2654362A1/fr not_active Abandoned
  • 2007-05-02 US US12/302,892 patent/US20090188233A1/en not_active Abandoned
  • 2007-05-02 EP EP07731395A patent/EP2029880A1/fr not_active Withdrawn
  • 2007-05-02 RU RU2009100999/06A patent/RU2009100999A/ru unknown
  • 2007-05-02 WO PCT/FR2007/000746 patent/WO2007147954A1/fr active Application Filing
  • 2007-05-02 BR BRPI0713507-6A patent/BRPI0713507A2/pt not_active IP Right Cessation
  • 2007-05-02 CN CN2007800233866A patent/CN101473130B/zh not_active Expired - Fee Related

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