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
  • F02K1/76—Control or regulation of thrust reversers
  • F02K1/763—Control or regulation of thrust reversers with actuating systems or actuating devices; Arrangement of actuators for thrust reversers
• • 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
  • F02K1/56—Reversing jet main flow
  • F02K1/62—Reversing jet main flow by blocking the rearward discharge by means of flaps
  • F02K1/625—Reversing jet main flow by blocking the rearward discharge by means of flaps the aft end of the engine cowling being movable to uncover openings 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
  • F02K1/54—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
• • 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
  • 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
  • F05D2250/00—Geometry
  • F05D2250/30—Arrangement of components
  • F05D2250/34—Arrangement of components translated

Definitions

• Thrust reverser of a turbojet engine nacelle comprising grids fixed to the movable hoods
• the present invention relates to a thrust reverser for an aircraft nacelle receiving a turbojet, and an aircraft nacelle equipped with such a thrust reverser.
• the engine sets for the aircraft comprise a nacelle forming a generally circular outer envelope, comprising inside a turbojet arranged along the longitudinal axis of this nacelle.
• the turbojet engine receives fresh air from the upstream or front side, and rejects on the downstream or rear side hot gases from the combustion of fuel, which give a certain thrust.
• fan blades arranged around this turbojet generate a large secondary flow of cold air along an annular vein passing between the engine and the nacelle, which adds a high thrust.
• Some nacelles include a thrust reversal system that closes at least part of the annular cold air duct, and rejects the secondary flow forward to generate a braking thrust of the aircraft.
• a known type of thrust reverser presented in particular by the document EP-A2-0321993, comprises rear movable covers that can slide axially backwards under the effect of actuators, by deploying flaps in the annular vein so to at least partially close this vein. These flaps return the flow of cold air radially outward through grids discovered during this sliding, comprising blades that direct the flow forward.
• the grids are integrated in the thickness of the movable covers, the flaps being folded below these grids, under their lower faces facing the axis of the nacelle.
• Each grid is fixed by a hinge to the front frame located upstream of these movable pots.
• Telescopic telescopes that are longitudinally located in the annular vein, have their front ends secured to the inside of the front frame, and their rear ends fixed inside a flap.
• a problem with this type of thrust reverser is that the cylinders remaining in the annular vein during normal operation of the turbojet engine, slow the flow of cold air and increase consumption.
• Another type of known thrust reverser presented in particular by US-A-5228641, comprises grids fixed to the front frame, which are integrated in the thickness of the movable covers when the inverter is closed.
• the flaps disposed below the grids have a front end connected to the movable cowl by a hinge, and a rear end connected by a rod running backwards, to a connecting arm which returns forward in order to be fixed. on the front frame.
• the present invention is intended to avoid these disadvantages of the prior art.
• a thrust reverser of a turbojet engine nacelle comprising movable covers which recoil with respect to a front frame by driving by the cylinders the tilting flaps initially located folded inside these hoods, for substantially close the annular cold air duct, and opening grids arranged around this vein which receive the cold air flow to return it forward, remarkable in that the grids are fixed to the movable hoods and slide with them.
• An advantage of this thrust reverser is that the grids being outside the movable covers, it can easily achieve hoods comprising a reduced radial thickness, which receive in an integrated manner the flaps and their control mechanisms comprising the cylinders.
• this vein may include a good aerodynamic profile ensuring the performance of the propulsion system.
• the grid having a less limited space may have a shape that is better adapted to the deflection of the flow.
• the thrust reverser according to the invention may further comprise one or more of the following features, which may be combined with one another.
• the flaps comprise a front end connected by a hinge to a movable cover, and a jack comprising a front end fixed to the frame, and the other end fixed to the rear of this flap.
• the cylinder is at the limit of the outer surface of the annular channel, the flap being connected to the movable cowl by a hinge which is remote from this cylinder radially outwardly. This is obtained by this distance when the flap is folded, a thrust of the cylinder giving a torque of effort on the flap that keeps it pressed on its limit stop.
• the jack disposed in the longitudinal axis of the flap is integrated in a longitudinal recess of the face of the flap turned radially towards the inside of the nacelle, which avoids leaving this cylinder protruding into the annular vein.
• the cylinder comprises below a closure plate fixed flat along the length, which adjusts to the face of the flap when it is folded to substantially close the longitudinal recess of the flap.
• This plate improves the aerodynamic surface of the annular vein.
• the closure plate comprises its rear end fixed to the rear part of the cylinder rod, and its front end slidingly attached to the body of this cylinder by a linear guide. In thrust reversal, this plate is spaced from the air flow to not slow it down.
• the rear portion of the flap bears radially outwardly when the inverter is closed, on an adjustable end stop that i can adjust the alignment of this flap with the neighboring surfaces.
• the rear end of the grilles is fixed to a spoiler located in front of the movable covers, a seal bearing on the front frame, which is located radially inside the grids.
• the thrust reverser comprises at the front of the movable covers, a seal bearing on the front frame. This seal gives a pressure balance facilitating the opening or closing of the covers.
• the front ends of grids are interconnected by a circular structure located upstream of the front frame, this structure providing a high rigidity with a reduced mass.
• the invention also relates to a turbojet engine nacelle comprising a thrust reverser comprising any one of the preceding features.
• FIG. 1 is a partial view in axial section passing through the center of a flap, an inverter according to the invention which is closed;
• FIG. 2 is a cross-sectional view of this shutter
• FIG. 3 is a longitudinal sectional detail view showing the sealing system of movable covers
• FIG. 4 shows the inverter at the beginning of opening, including the jack being extended
• FIG. 5 shows the inverter more open, including the cylinder in full extension
• Figures 1 and 2 present pa rti e behind a nacel l e turbojet, comprising a front frame 2 fixed on the structure located upstream of this part, and movable covers 10 fitted behind this frame.
• the rear part of the nacelle is covered by two movable covers 10, each forming a semicircle in a transverse plane.
• Each cover 10 is guided axially by longitudinal guiding means, which allow a sliding backwards under the effect of actuators not shown, bearing on the fixed structure upstream of the movable covers 1 0.
• the covers 1 0 comprise a locking system in the closed position, which is not shown.
• the nacel may have an annular movable cowl 10 which likewise slides backward to open the thrust reverser.
• the secondary annular vein 4 comprises a radially outer contour comprising flaps 8 fitted inside the movable hoods 10 so as to give an aerodynamic continuity, and a radially internal contour formed by the fixed internal structure 6.
• the rear end of the grids 1 2 is fixed to a spoiler 14 located in front of the movable covers 1 0, that i form a retou r from the outer surface of these covers, towards the center of the nacelle.
• the grids can slide freely through openings in the front frame 2, in order to follow the movement of the covers 10 when the inverter opens.
• the cap drive system 10 including the actuators may be attached to the upstream portion of the grid structure 12, to move the assembly including the gills and covers. This disposition frees entirely the passage of air in the structure of the grids 12 in reverse thrust, but impinges on the front cover of the engine.
• the drive system of the hoods 10 can be fixed to the grids 12 either in the plane of the grids or radially above or below their structure.
• the drive system of the hoods 10 can also be fixed on the upstream part of the structure of these hoods, by integrating between them em ents of the grids 12. In these of them va ria nts the system of drive is in the air passage in reverse thrust.
• Each flap 8 comprises an arm extending forwardly inside the movable hood 1 0, ending at its front end by a hinge 1 6 connected to the movable hood, which is arranged just behind the spoiler return 14.
• the rear portion of the flap 8 bears radially outwardly on a limit stop 18, which positions the flap so as to adjust its face in continuity with the inner surfaces of the front frame 2 and the movable flap 10.
• the end stops 18 may be adjustable, in order to refine the position of the flaps 8 in the aerodynamic flow.
• Each flap 8 comprises a telescopic jack 20 disposed in the longitudinal axis of this flap, which is fully integrated in a longitudinal recess of the face of the shutter facing the inside of the nacelle, so as to adjust to the surface outside of the annular vein 4 without exceeding in this vein.
• the front end of the jack 20 is fixed by a pivot to the front frame 2, the rear end is fixed by a pivot also to a rear part of the flap 8.
• Each telescopic jack 20 comprises a body containing on the front side a helical compression spring, which exerts a permanent pressure on the front end of its rod 22, to push it backwards to tend to put this cylinder in extension.
• This optional closure plate 32 is shown in FIGS. 8 and 9. It will be noted that the flaps 8 are kept permanently tensioned by the pressure of the springs of the jacks 20 which tend to push them on their limit stops 1 8, with a certain torque depending on the radial distance between the axis of this end. cylinder and the hinge 1 6 flaps. This pressure avoids flutter flaps 8 which would slow the flow of secondary air.
• Figure 3 shows a hood 1 0 in its forward position, the thrust reverser being completely closed.
• the radially inner end of the return spoiler 14 is pressed forward on a seal 30, which is itself resting on the front frame 2, radially inside the grids 1 2.
• a seal 30 which is itself resting on the front frame 2, radially inside the grids 1 2.
• Arrangement of the grids 8 integrated upstream of the structure of the movable hoods 1 0, allows this arrangement of the seal that i realizes a pressure eeg uil facilitating the opening or closing of these covers.
• FIG. 4 shows the inverter at the beginning of opening, the movable covers 10 having begun to move back under the effect of their actuators.
• the grids 12 begin to leave the front frame 2.
• the cylinders 20 are being extended. Since the rods 22 are not fully extended, these jacks 20 can continue to deploy without exerting a retaining force on the rear part of the flaps 8 which do not tilt, and remain plated inside the movable covers 10.
• Figure 5 shows the inverter more open with the moving hoods 10 which continue to move back.
• the cylinders 20 arrive at full extension with the rods 22 fully out, but the flaps 8 still do not rock.
• Figure 6 shows the inverter more open still, the rod 22 which can not move back, began to tilt the flap 8 by pulling its rear part down.
• FIG. 7 shows the fully open inverter, the movable covers 10 are in their maximum rear positions, the shutters 8 are completely lowered when arriving near the fixed internal structure 6.
• the grids 12 come out more and more of the front frame 2, to finish completely. outlets so as to clear their entire surfaces that allow to deflect the secondary flow.
• the front ends of all the grids 12 are connected together by a continuous circular structure which is upstream of the front frame 2, which allows a simple way with a reduced mass to obtain a particularly rigid grid assembly.
• the length of the grids 1 2 is adapted accordingly, so that their front ends remain upstream of the frame 2 when the inverter is fully open.
• the inner and outer aerodynamic profiles of this vein can be optimized, the fuel consumption is improved.
• the gap in the movable hoods 1 0 not including the grids 1 2 makes it possible to optimize the position of the hinge before the flaps 8, which can be close to the outer surface of these covers to obtain with the choice of anchor points of the cylinders 20, a good kinematics for the deployment of the flaps.
• a rather large radial gap between the jacks 20 and the hinge points before 16 of the flaps 8 makes it possible for these jacks to maintain high torque on the folded flaps. It also provides a good distribution of effort and better maneuverability.
• FIGS. 8 and 9 show the closure plate 32 comprising its rear end fastened to the rear part of the rod of the jack 22, and its front end slidingly attached to the body of this jack by linear guiding, such as a guide rail.
• the longitudinal hollow of the flap 8 is closed by the plate 32 forming a fairing to improve the aerodynamic performance.
• the body of the jack 20 is generally disengaged from the closure plate 32 which is cast forwardly with the rod 22, allowing a smooth flow of the flow of the fluid. inversion, and thus an improvement in inversion performance.

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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)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49003888

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (6)

• 2013
  • 2013-06-07 FR FR1355279A patent/FR3006715B1/fr not_active Expired - Fee Related
• 2014
  • 2014-06-05 CA CA2908678A patent/CA2908678A1/fr not_active Abandoned
  • 2014-06-05 EP EP14733272.0A patent/EP3004614A1/de not_active Withdrawn
  • 2014-06-05 WO PCT/FR2014/051349 patent/WO2014195646A1/fr active Application Filing

Non-Patent Citations (1)

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