FR3061699A1 - AIRCRAFT ENGINE ASSEMBLY - Google Patents

Abstract

The invention relates to an engine assembly (1) for an aircraft and a method for maintaining such an engine assembly. The engine assembly (1) comprises a coupling device (3) for a turboprop (2) under an aircraft wing having a fixed rigid structure (4) intended to be fixed to the wing. According to the invention, the attachment device (3) comprises a mobile part (5) supporting the turboprop (2). The movable part (5) is movable with respect to the fixed rigid structure (4) between a retracted position in which the movable part (5) is housed in the fixed rigid structure (4) and an extended position in which the movable part (4) 5) is at least partially outside the fixed rigid structure (4).

Description

@ Holder (s): SAFRAN AIRCRAFT ENGINES.

O Extension request (s):

® Agent (s): CABINET GERMAIN & MAUREAU.

FR 3 061 699 - A1 ® ENGINE ASSEMBLY FOR AIRCRAFT.

(57) The invention relates to an engine assembly (1) for an aircraft and to a method of maintaining such an engine assembly. The engine assembly (1) comprises an attachment device (3) of a turboprop engine (2) under an aircraft wing comprising a fixed rigid structure (4) intended to be fixed to the wing.

According to the invention, the attachment device (3) comprises a movable part (5) supporting the turboprop (2). The mobile part (5) is movable relative to the fixed rigid structure (4) between a retracted position in which the mobile part (5) is housed in the fixed rigid structure (4) and a deployed position in which the mobile part ( 5) is at least partially outside the fixed rigid structure (4).

Aircraft engine assembly

The present invention relates to an engine assembly comprising a device for attaching a turboprop under an aircraft wing, and to a method of maintaining such an engine assembly.

This type of engine assembly can be used on any type of aircraft comprising turboprop engines suspended from its wing. It will be recalled that a turboprop is a propulsion unit comprising a non-faired propeller, driven by an engine generally consisting of a turbomachine also called a "gas generator".

According to the prior art, to suspend a turboprop under an aircraft wing, there is conventionally proposed a fastening device known under the name of "cradle" and comprising a rigid structure.

The rigid structure may comprise several transverse frames spaced from one another, and interconnected in particular by a plurality of connecting rods, these then forming jointly with the transverse frames a structure called trellis structure, as shown for example in patent document EP1538080.

The engine assembly includes an equipment installation zone, also called the main installation zone and which corresponds to a compartment called “core zone” in English, situated around the casings of the gas generator and delimited externally by cowls forming a turboprop nacelle. The majority of the equipment essential to the operation of the turboprop is installed mainly in this equipment installation zone located upstream of the turboprop (at the front relative to the normal direction of advance of the aircraft), where the temperature is less critical than downstream around the turbine casings.

This equipment needs to be frequently checked and sometimes replaced during a maintenance operation.

However, the architecture of this trellis is problematic for accessibility to this equipment by an operator during a maintenance operation on the turboprop.

The invention aims to solve all or part of these drawbacks by proposing an engine assembly comprising a device for hooking up a turboprop making it possible to facilitate accessibility to this equipment during a maintenance operation on the turboprop.

The invention relates to an engine assembly for an aircraft comprising a device for hooking a turboprop under an aircraft wing. The attachment device comprises a fixed rigid structure intended to be fixed to the wing.

According to the invention, the attachment device comprises a movable part supporting the turboprop.

The mobile part is movable relative to the fixed rigid structure between a retracted, or operating, position in which the mobile part is housed under the fixed rigid structure and a deployed, or maintenance, position, in which the mobile part is at least partially outside the fixed rigid structure.

The invention thus provides an engine assembly comprising a device for attaching a turboprop making it possible to facilitate maintenance operations on the turboprop.

The translation of the movable part of the attachment device allows operators to more easily access the turboprop equipment. Operators are no longer bothered by the trellis structure of conventional hanging devices.

During a maintenance operation, it suffices simply to translate the movable part relative to the fixed rigid structure to clear the installation area of the equipment outside the fixed rigid structure.

The operator can then easily access the turboprop equipment located in the equipment installation area.

Maintenance times and costs are reduced. The hardship for the operator is also reduced since he no longer has to twist through the trellis to access the equipment to be repaired. In addition, the positioning of the tools for the possible dismantling of an equipment is not hampered by the fixed rigid structure.

According to an advantageous embodiment, the attachment device comprises translation means allowing the translation of the movable part between the retracted position and the deployed position in a longitudinal direction X. Preferably, this longitudinal direction X corresponds to the longitudinal axis of the gas generator that the turboprop comprises.

According to a variant, the fixed rigid structure comprises a first slide and the movable part comprises a second slide capable of sliding along the first slide. The translation means are formed by the first slide and the second slide. This provides a simple slide system.

By way of example, the first slider comprises a central groove extending in the longitudinal direction X. The second slider comprises a longitudinal rail housed in the central groove of the first slider.

The first slide comprises at least one lateral groove hollowed out in one of the side walls delimiting the central groove and skirting the latter in the longitudinal direction X. The second slide comprises at least one lateral rib projecting on one of the side walls of the longitudinal rail and extending along the latter. The lateral rib is inserted and slides in the lateral groove of the first slide. This strengthens the strength of the proposed slide system. The translation can be carried out safely for the operator.

Preferably, the motor assembly comprises a return means housed in the central groove of the first slide. The return means is on the one hand connected to a rear end of the longitudinal rail of the second slide and on the other hand connected to a rear end of the first slide so as to exert a return force directed towards the rear end of the first slide . The return means participates in maintaining the movable part in the retracted position when the aircraft is in flight, improving safety.

As a variant, the motor assembly comprises actuating means allowing the translation of the mobile part between the retracted position and the deployed position.

By way of example, the actuation means comprise at least one jack housed in the central groove of the first slide. The cylinder is on the one hand connected to the rear end of the second slide and on the other hand connected to the rear end of the first slide. This makes it possible to position the mobile part in the deployed position in a simple manner and without effort for the operator.

Advantageously, the second slide comprises a front end fixed to the turboprop by an upstream fixing means. The rear end of the second slide is fixed to the turboprop by at least two downstream fixing means.

The engine assembly comprises two lateral fixing means connecting the turboprop to two longitudinal members of the fixed rigid structure when the movable part is in the retracted position. These lateral fixing means make it possible to securely hang the turbomachine on the rigid rigid structure in the retracted position, preventing the turbomachine from bending. They are removable and can be easily disconnected from the turbomachine before the moving part translates to the deployed position.

The invention also relates to a maintenance method for an engine assembly for an aircraft comprising a device for hooking a turboprop under an aircraft wing, as defined above.

According to the invention, the method comprises the following steps:

- disconnection of the lateral fastening means of the turboprop,

- Translation of the movable part of the attachment device from the retracted position to the deployed position so as to position a zone for installing turboprop equipment outside the fixed rigid structure.

Other characteristics and advantages of the invention will emerge on reading the description which follows, given solely by way of example, with reference to the appended figures, which illustrate:

FIG. 1, a diagram of an engine assembly for an aircraft according to the invention in the retracted position;

Figure 2, a diagram of this engine assembly in the deployed position;

Figure 3, a perspective view of this motor assembly in the deployed position;

Figure 4, a detailed perspective view of the rear of the engine assembly in the deployed position;

Figure 5, a diagram of an isolating pad;

Figure 6, a diagram showing the use of a maintenance part during a maintenance operation.

Throughout the description which follows, by convention, the longitudinal direction X is called the direction which is parallel to the longitudinal direction of the turboprop 2.

On the other hand, the terms front and rear are to be considered with respect to a direction of advance of the aircraft encountered following the thrust exerted by the turboprop engines 2, this direction being represented schematically by the arrow of the longitudinal direction X.

FIG. 1 represents a diagram of an engine assembly 1 for aircraft according to the invention in the retracted position.

The engine assembly 1 comprises an attachment device 3 for a turboprop 2 under an aircraft wing.

The attachment device 3 comprises a fixed rigid structure 4 fixed to the wing. The fixed rigid structure 4 can be called "cradle". The fixed rigid structure 4 comprises two longitudinal members 24 parallel to the longitudinal direction X.

According to the invention, the attachment device 3 comprises a movable part 5 supporting the turboprop 2.

The movable part 5 is movable relative to the fixed rigid structure 4 between a retracted or retracted position in which the mobile part 5 is housed under the fixed rigid structure 4, as shown in FIG. 1, and a deployed position in which the part mobile 5 is partially outside of the fixed rigid structure 4, as shown in Figures 2 to 4. In other words, in the deployed position, the attachment device 3 is open to allow a maintenance operation.

In the retracted position, generally corresponding to an operating position of the engine assembly, the turboprop 2 is positioned under the fixed rigid structure 4. The turboprop 2 is also fixed to the fixed rigid structure 4, as described later.

In the deployed position, generally corresponding to a maintenance position of the engine assembly, the turboprop 2 is positioned at least partially outside of the fixed rigid structure 4. The turboprop 2 is then disconnected from the fixed rigid structure 4.

The turboprop 2 described in this example commonly comprises a gearbox 27 or reduction gear called a “Propeller Gear Box” (PGB), a bore 28 for the output of a propeller shaft, a transmission shaft 29 and a gas generator. 30 comprising a compressor 31, a combustion chamber 32 and a high pressure turbine 33.

The turboprop 2 comprises an equipment installation zone 25, situated around the casings of the gas generator 30 and on an upstream part of the latter. In the deployed position (FIG. 2), the equipment installation area 25 is clear of the fixed rigid structure 4, that is to say outside of it, or in other words, offset according to the longitudinal direction X with respect to it.

In this example, the mobile part 5 moves over a distance corresponding approximately to a quarter of the length of the attachment device 3. This distance can be greater or less.

The displacement must be sufficient to free access to the equipment installation area 25 and must preferably correspond to at least the length of this equipment installation area 25.

The attachment device 3 comprises translation means 6 allowing the translation of the movable part 5 between the retracted position and the deployed position in the longitudinal direction X.

More precisely, during a maintenance operation of the turboprop 2, the movable part 5 translates in the longitudinal direction X and towards the front of the engine assembly 1 to the deployed position.

During a maintenance operation, the operator can easily access this equipment installation area 25.

When the aircraft is positioned on the tarmac, the turboprop 2 is positioned below the wing and the equipment installation zone 25 is located around the turboprop 2.

The fixed rigid structure 4 comprises a first slide 7 and the mobile part 5 comprises a second slide 8.

The translation means 6 are formed by the first slide 7 and the second slide 8. The second slide 8 slides or slides along the first slide 7 and relative to the latter. The first slide 7 and the second slide 8 form a system of slides.

The first slide 7 comprises a central groove 9 extending in the longitudinal direction X.

The central groove 9 preferably extends over the entire length of the first slide 7 and has a quadrilateral section, as shown in FIG. 4.

The second slide 8 comprises a longitudinal rail 10 housed in the central groove 9 of the first slide 7. The longitudinal rail 10 has a generally quadrilateral section and has substantially the same length as that of the central groove 9. The longitudinal rail 10 and the groove central 9 form a rail-slide assembly.

The first slide 7 comprises at least one lateral groove 11 hollowed out in one of the side walls 12 delimiting the central groove 9 of the first slide 7. Each lateral groove 11 runs along the central groove 9 in the longitudinal direction X and extends to the inside the first slide 7 in a direction substantially perpendicular to the longitudinal direction X.

In the example of Figures 1 to 4, the first slide 7 comprises two side walls 12 each having two side grooves 11 parallel to each other.

The second slide 8 comprises at least one lateral rib 13 projecting from one of the side walls 14 of the longitudinal rail 10 and extending along the latter. Each lateral rib 13 extends perpendicular to the longitudinal direction X.

The lateral rib 13 of the second slide 8 is inserted and slides in one of the lateral grooves 11 of the first slide 7.

In the example of FIGS. 1 to 4, the longitudinal rail 10 of the second slide 8 comprises two side walls 14 each comprising two side ribs 13. Each side rib 13 slides in a respective central groove 9 of the first slide 7.

The motor assembly 1 comprises a return means 15 housed in the central groove 9 of the first slide 7.

The return means 15 is on the one hand connected to a rear end 16 of the longitudinal rail 10 of the second slide 8 and on the other hand connected to a rear end 17 of the first slide 7 so as to exert a return force directed towards the rear end 17 of the first slide 7. The restoring force is directed in a direction opposite to the longitudinal direction X.

The return means 15 preferably comprises a return spring 15 or compression.

The return means 15 makes it possible to return or maintain the mobile part 5 in the retracted position.

The motor assembly 1 comprises actuating means 18 allowing the translation of the mobile part 5 between the retracted position and the deployed position.

More particularly, the actuating means 18 oppose the force exerted by the return means 15 to translate the movable part 5 from the retracted position to the deployed position. The actuating means 18 make it possible to open the attachment device 3.

When the maintenance operation is finished, the actuating means 18 bring the movable part 5 back from the deployed position to the retracted position.

The actuating means 18 comprise at least one jack 18 housed in the central groove 9 of the first slide 7. The jack 18 is on the one hand connected to the rear end 16 of the second slide 8 and on the other hand connected to the rear end 17 of the first slide 7.

The example in FIG. 4 shows actuation means 18 comprising two jacks 18.

When the aircraft is in flight, the assembly formed by the return means 15 and the actuation means 18 ensures that the attachment device 3 is closed correctly.

As a variant or in addition, the jacks 18 can be associated with latches to keep them locked (not shown).

The second slide 8, integral with the movable part 5, comprises a front end 19 fixed to the turboprop 2 by an upstream fixing means 20. More specifically, the front end 19 of the second slide 8 is fixed to the upper part 34 of the gearbox 27 of turboprop engine 2.

The rear end 16 of the second slide 8 is fixed to the turboprop 2 by at least two downstream fixing means 21.

The engine assembly 1 comprises two lateral fixing means 23, as shown in FIG. 1, connecting the turboprop 2 to the two longitudinal members 24 of the fixed rigid structure 4. Each lateral fixing means 23 is removable with respect to one and / or the other of the two structures it connects. In other words, to allow translation of the mobile part 5 between the retracted position and the deployed position, each lateral fixing means 23 must be uncoupled from the gearbox 27 and / or from a spar 24.

The lateral fixing means 23 and the side members 24 are arranged on each side of the engine assembly 1.

As shown in FIG. 4, each lateral fixing means 23 is fixed to one of the side walls 14 of the second slide 8.

Each beam 24 is connected to the first slide 7 by means of several arches 26. The example of FIG. 1 shows four arches 26 on each side of the engine assembly 1.

Each downstream fastening means 21 fixed to the rear end 16 of the second slide 8 is connected to the turboprop 2 via a connecting rod 22. The turboprop 2 can include yokes (not shown) on which the connecting rods are fixed.

The motor assembly 1 comprises at least three fixing means 20, 23 at its front part and at least two fixing means 21 at its rear part.

The three fixing means 20, 23 positioned at the front of the engine assembly 1 are positioned upstream of the compressor 31.

The two fixing means 21 positioned at the rear of the engine assembly 1 are positioned downstream of the high pressure turbine 33.

The fixing means 20, 21, 23 include insulating pads 35 as described in patent FR2101490 or patent FR2917711, by way of example.

An isolating pad 35, as illustrated in FIG. 5, allows a "filtering" connection to dampen vibrations.

For this, the insulating pad 35 comprises laminates of prestressed elastomers 36, for example by means of prestressing flanges 37.

The upstream fixing means 20 and the lateral fixing means 23 each comprise a solid rod 38 which connects the isolating pad 35 to the gearbox 27 of the turboprop 2 removably.

FIG. 5 illustrates by way of example a lateral fixing means 23 comprising such a rod 38 connecting a spar 24 of the fixed rigid structure 4 to the gearbox 27 of the turboprop engine 2 by means of an isolating pad 35.

In this example, the rod 38 can be detached from the gearbox 27 in order to decouple the turboprop 2 relative to the fixed rigid structure 4.

Regarding the downstream fixing means 21, the latter do not include a rod but insulating pads 35 connected to the connecting rods 22. The downstream fixing means 21 also comprise laminates of elastomers, for example frustoconical and centered around an axis on which the connecting rod 22 is articulated (not shown), according to a principle described in patent FR2917711.

The invention also relates to a maintenance method for an engine assembly 1, as described above, comprising a step of disconnection or separation of the lateral fixing means 23 of the turboprop engine 2 and a step of translation of the movable part 5 of the device. hooking 3 from the retracted position to the deployed position so as to position an equipment installation zone 25 of the turboprop 2 outside of the fixed rigid structure 4.

In the retracted position, the turboprop 2 is supported by the mobile part 5 via the upstream fixing means 20, the two downstream fixing means 21 and by the two lateral fixing means 23.

During the maintenance operation, the mobile part 5 is translated to the deployed position. The turboprop 2 is supported by the movable part 5 only via the upstream fixing means 20 and the two downstream fixing means 21.

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As stated previously, the separation or disconnection of the two lateral fixing means 23 is carried out for example by uncoupling the rod connecting the isolating pad 35 to the gearbox T1 of the turboprop engine 2. The coupling between the rod 38 and the gearbox Tl can be achieved by nuts.

In order to limit the weight carried by the upstream fastening means 20 during the maintenance operation, and as illustrated in FIG. 6, it is possible to use an attached maintenance part 39 which is fixed on the one hand to a part upper front 46 of the fixed rigid structure 4 and on the other hand on the gearbox Tl of the turboprop 2 to prevent any deformation of the turboprop 2.The maintenance part 39 is connected to the gearbox Tl of the turboprop 2 by the intermediate of a support sling 40 comprising for example two arms which each hang on one side of the gearbox 27.

The maintenance part 39 comprises a longitudinal part 41 substantially parallel to the longitudinal direction X when the maintenance part is fixed to the fixed rigid structure 4. The support sling 40 connects the longitudinal part 41 to the turboprop 2.

The maintenance part 39 also comprises an inclined part 42 relative to the longitudinal part 41 comprising an end 43 fixed to the fixed rigid structure 4.

The inclined part 42 comprises two arms 44, 45 substantially perpendicular to the latter and fixed to the fixed rigid structure 4.

The invention is described in the foregoing by way of example. It is understood that a person skilled in the art is able to carry out different alternative embodiments of the invention without going beyond the ambit of the invention.

Claims (10)

1. Engine assembly (1) for an aircraft comprising a fastening device (3) of a turboprop (2) under an aircraft wing, said fastening device (3) comprising a fixed rigid structure (4) intended for be attached to the wing, characterized in that the attachment device (3) comprises: a mobile part (5) supporting the turboprop (2), said mobile part (5) being mobile relative to the fixed rigid structure (4) between a retracted position in which the mobile part (5) is housed in the fixed rigid structure (4) and a deployed position in which the movable part (5) is at least partially outside the fixed rigid structure (4). 2. Motor assembly (1) according to claim 1, characterized in that the attachment device (3) comprises translation means (6) allowing the translation of the mobile part (5) between the retracted position and the deployed position in a longitudinal direction (X). 3. Motor assembly (1) according to claim 2, characterized in that the fixed rigid structure (4) comprises a first slide (7) and the movable part (5) comprises a second slide (8) capable of sliding along the first slide (7), the translation means (6) being formed by the first slide (7) and the second slide (8). 4. Motor assembly (1) according to claim 3, characterized in that the first slide (7) comprises a central groove (9) extending in the longitudinal direction (X), the second slide (8) comprising a longitudinal rail (10) housed in the central groove (9) of the first slide (7). 5. Motor assembly (1) according to claim 4, characterized in that the first slide (7) comprises at least one lateral groove (11) hollowed out in one of the side walls (12) delimiting the central groove (9) and skirting that in the direction (X), the second slide (8) comprising at least one lateral rib (13) projecting from one of the side walls (14) of the longitudinal rail (10) and extending along the latter, the lateral rib (13) sliding in the lateral groove (11) of the first slide (7). 6. Motor assembly (1) according to any one of claims 4 or 5, characterized in that it comprises a return means (15) housed in the central groove (9) of the first slide (7), said means of reminder (15) being on the one hand connected to a rear end (16) of the longitudinal rail (10) of the second slide (8) and on the other hand connected to a rear end (17) of the first slide (7) exerting a restoring force directed towards the rear end (17) of the first slide (7). 7. Motor assembly (1) according to any one of claims 1 to 6, characterized in that it comprises actuating means (18) allowing the translation of the movable part (5) between the retracted position and the position deployed. 8. Motor assembly (1) according to claim 7, characterized in that the actuating means (18) comprise at least one jack (18) housed in the central groove (9) of the first slide (7), said jack ( 18) being on the one hand connected to the rear end (16) of the second slide (8) and on the other hand connected to the rear end (17) of the first slide (7). 9. Motor assembly (1) according to any one of claims 3 to 8, characterized in that the second slide (8) comprises a front end (19) fixed to the turboprop (2) by an upstream fixing means (20) , the rear end (16) of the second slide (8) being fixed to the turboprop (2) by at least two downstream fixing means (21), the engine assembly (1) comprising two lateral fixing means (23) connecting the turboprop (2) with two beams (24) of the fixed rigid structure (4) when the mobile part (5) is in the retracted position. 10. Maintenance method for an engine assembly (1) for an aircraft comprising an attachment device (3) of a turboprop (2) under an aircraft wing, said attachment device (3) comprising a rigid rigid structure (4) fixed to the wing and a mobile part (5) supporting the turboprop (2), as defined in any one of claims 1 to 9, said mobile part (5) being mobile relative to the fixed rigid structure (4) between a retracted position in which the mobile part (5) is housed under the fixed rigid structure (4) and a deployed position in which the mobile part (5) is partially outside the fixed rigid structure (4), the engine assembly (1) comprising two lateral fixing means (23) connecting the turboprop (2) to the fixed rigid structure (4) when the movable part (5) is in the retracted position, characterized in that it comprises the following steps : disconnection of the lateral fixing means (23) of the turboprop engine (2), and translation of the movable part (5) of the hooking device (3) from the retracted position to the deployed position so as to position an installation area d 'equipment (25) of the turboprop (2) outside the fixed rigid structure (4). 1/3 x___ Fig. 1 x 3/3