FR3061147A1 - AIRBORNE TYPE AIRBORNE TURBOPROPOWER WITH DEPTH TREE COMPRISING MEANS OF SUSPENSION TO AN AIRCRAFT PYLON - Google Patents

Abstract

The main object of the invention is a turboprop propeller (1) of propeller shaft type (2), comprising a propeller shaft (2) and a motor comprising a gas turbine (3) which comprises a turbine shaft (4), the latter extending parallel to the propeller shaft (2) and comprising a rear end coupled to a rear end of the propeller shaft (2) via a main gear (6), the motor comprising a front portion equipped with an air inlet sleeve (7). This turboprop (1) is characterized in that it comprises first front suspension means (10) of the front part of the engine to a front part of a pylon (13) fixed to a wing (14) of the aircraft and second rear suspension means (12) from a rear part of the engine to a rear part of the pylon (13) and / or to the main gear (6).

Description

@ Holder (s): SAFRAN AIRCRAFT ENGINES.

O Extension request (s):

Agent (s): BREVALEX Limited liability company.

* 54) AIRCRAFT TURBOPROPELLER OF TYPE WITH SHAFT COMPRISING MEANS OF SUSPENSION TO AN AIRCRAFT PYLONE.

FR 3 061 147 - A1 (57) The main object of the invention is a turboprop (1) of an aircraft type with a propeller shaft (2) offset, comprising a propeller shaft (2) and an engine comprising a gas turbine (3) which comprises a turbine shaft (4), the latter extending parallel to the propeller shaft (2) and comprising a rear end coupled to a rear end of the shaft propeller (2) by means of a main reduction gear (6), the motor comprising a front part equipped with an air intake sleeve (7). This turboprop (1) is characterized in that it comprises first means for front suspension (10) of the front part of the engine to a front part of a pylon (13) fixed to a wing (14) of the aircraft and second rear suspension means (12) from a rear part of the engine to a rear part of the pylon (13) and / or to the main reducer (6).

REMOTE SHAFT TYPE AIRCRAFT TURBOPROPELLER HAVING MEANS FOR SUSPENSION TO AN AIRCRAFT PYLON

DESCRIPTION

TECHNICAL AREA

The present invention relates to the general field of turbomachinery, and more particularly to an installation design of an aircraft turboprop of the type with a power shaft (or propeller shaft) called "offset", that is to say -display extending next to a turbine shaft of the turbomachine and not in its extension.

The invention relates more precisely to an aircraft turboprop of the deported propeller shaft type comprising means for suspending from an aircraft pylon, an assembly and an aircraft comprising such a turboprop, as well as a method of removing the engine. of such a turboprop.

PRIOR STATE OF THE ART

Throughout the description, it is noted that the terms upstream and downstream, or respectively front and rear, are to be considered with respect to a main direction F of normal gas flow (from upstream to downstream) for a turboprop 1.

A turboprop is an aircraft engine comprising a propeller propelled by a gas turbine, and whose main thrust is obtained only by the rotation of this propeller.

According to a first known architecture of a turboprop, the gas turbine shaft is coupled at its front end to a propeller shaft by a main reducer also called propeller reducer or power transmission box, usually designated by the acronym PGB (for "Power Gear Box" or also "Propeller Gear Box" in English), comprising, for example, two planetary reduction trains, so that the propeller shaft extends in the extension of the shaft turbine. The front suspension, comprising flexible studs making it possible to filter certain vibrations coming from the propeller, is then mounted on the main reduction gear.

Furthermore, according to a particular architecture known as an inverted free turbine, on the basis of this first architecture, the accessory box, usually designated by the acronym AGB (for “Accessory Gear Box” in English), is then coupled to the rear end of the turbine shaft. In this way, a compact assembly is obtained in which the accessory box remains fairly easily accessible for any maintenance operation. An accessory box makes it possible to rotate additional accessories or equipment typically comprising one or more oil and fuel pumps, a starter and an alternator.

The main reducer then being mounted very far from the wing of the aircraft, its resistive torque requires having a cradle type structure for the installation of the turboprop, that is to say a structure formed of frames and connecting rods, or else a hybrid type structure, that is to say a cradle type structure with pylon, making it possible to take up the efforts of the propeller and the main reduction gear to transmit them to the aircraft.

Also, in order to minimize the forces passing through such a structure towards the aircraft, it is advantageous to provide the mounting of the main reducer at the rear of the turboprop engine and to transmit power to the propeller by means of a remote power shaft.

Consequently, according to a second known architecture of a turboprop, this comprises a remote power shaft (or propeller shaft). An aircraft turbomachine architecture with a remote power shaft is found for example on engines for helicopters, for example such as those of the Arriel range of the company Turbomeca. A cradle type structure is generally used for the installation of such a turbomachine on an aircraft.

An exemplary embodiment according to this second architecture is illustrated by the turboprop 1 for aircraft shown diagrammatically in lateral view in FIG. 1. The propeller shaft 2 extends over the entire length of the turboprop 1, and the turbine gas 3 extends along this propeller shaft 2. This gas turbine 3 comprises a turbine shaft 4 extending along a longitudinal axis, and a main reduction gear 6 is coupled to the rear end of this shaft turbine 4 and at the rear end of the propeller shaft 2. The turbine shaft 4 is extended downstream of the gas turbine 3 to pass through a wall of an exhaust nozzle and come to mate with the main gear gearbox. The main reduction gear 6 is then located at the rear of the turboprop 1, that is to say at its end opposite to the front end which includes the propulsion propeller 5.

As can be seen in FIG. 1, the front end of the gas turbine 3 is equipped with an air inlet sleeve 7, for example in the form of a wall of revolution formed by a casing or the like surrounding a longitudinal axis formed by the turbine shaft 4. Other forms of air intake sleeve are of course possible, and in particular, the upstream opening of the air duct forming the sleeve can be offset towards the low relative to the longitudinal axis of the turbine shaft so that the incoming air is not obstructed by the propeller hub. The accessories box 8 is attached to a lower part of a casing of the gas turbine 3, and comprises a gearbox driven by the turbine shaft 4.

This drive is conventionally provided by a radial shaft 9, perpendicular to the turbine shaft 4, and which is coupled to the latter by two non-visible bevel gears. The radial shaft 9 passes through the wall of the air duct 7, or the casing of the gas turbine 3, in order to be coupled at its other end to the accessory box 8.

This other coupling is ensured by another bevel gear by means of two other bevel gears to drive at least one shaft 19 for driving a piece of equipment mounted on the accessory box 8, which extends parallel to the turbine shaft 4.

With the architecture of the turboprop 1 with a remote power shaft of FIG. 1, the entire turboprop is conventionally installed in a cradle type structure, formed of frames and connecting rods. The removal (or disassembly) of the engine generally entails the obligation to disengage the entire turboprop with respect to the cradle, that is to say also to deposit the propeller 5 and / or the main reduction gear 6. It would however be desirable to be able to remove only the motor, that is to say to be able to leave the propeller and the main reduction gear in place when removing the motor, or even also leave in place at least some of the equipment usually installed on the housing accessories, in particular for reasons of reduced maintenance and safety operations.

STATEMENT OF THE INVENTION

The object of the invention is to at least partially remedy the needs mentioned above and the drawbacks relating to the embodiments of the prior art.

In particular, the invention aims to provide an installation architecture of a turboprop type with a remote power shaft making it possible to facilitate the disassembly of the engine and also to reduce the mass of the structure of an aircraft.

According to one of its aspects, the subject of the invention is therefore an aircraft turboprop of the type with a remote propeller shaft, comprising a propeller shaft and an engine comprising a gas turbine which comprises a turbine shaft. , the latter extending parallel to the propeller shaft and comprising a rear end coupled to a rear end of the propeller shaft via a main reduction gear, the motor comprising a front part equipped with an air intake sleeve, characterized in that it comprises first means for suspending the front part of the engine from the front to a front part of a pylon fixed to a wing of the aircraft and second means for suspending rear from a rear part of the engine to a rear part of the pylon and / or to the main reducer.

Thanks to the invention, it is possible to minimize the forces transmitted to the structure of an aircraft. It is thus possible to obtain an optimal main reduction gear assembly, in particular practically in the middle of the wing of the aircraft, and in particular close to the front spar of the wing of the aircraft, so as to be able to minimize the mass. of the aircraft structure. In addition, thanks to the installation concept in accordance with the invention, the disassembly of the engine is facilitated by leaving the propeller and the main reduction gear in place, and in particular using the same techniques as those used for turbojets, in particular hoisting parts mounted on the pylon. In addition, the fact of using a pylon also makes it possible to fix the nacelle thereon, and therefore to have a nacelle comparable to turbojets, that is to say to have a nacelle formed by two half-covers, which facilitates access to the engine. In addition, the pylon can, if necessary, serve as a fire-resistant zone to protect equipment.

Conventionally, the pylon, also called a suspension pylon, is a rigid structural part constituting the connection interface between the engine and the wing of the aircraft. It allows the forces from the engine to be transmitted to the structure of the aircraft. It also has the function of ensuring the progress of the easements. The pylon generally has an elongated structure of rectangular section of box type. It is formed by assembling upper and lower beams and side panels connected together by means of transverse ribs. The pylon advantageously comprises means for fixing to the engine and on its upper part means for fixing to the wing of the aircraft.

The turboprop according to the invention may also include one or more of the following characteristics taken in isolation or according to any possible technical combination.

Preferably, the second rear suspension means allow the attachment of a rear part of the engine to a rear part of the pylon.

Furthermore, the first front suspension means may comprise an intermediate suspension device, mounted on the propeller shaft, a first member for suspending the front part of the engine from the intermediate suspension device and a second device for suspending the device. of intermediate suspension at the front of the pylon.

The intermediate suspension device can advantageously comprise a bearing box crossed by the propeller shaft.

In other words, the pylon can support the propeller shaft through the bearing box. This bearing box is advantageously fitted with flexible studs and located behind the propeller. It allows the moment of the IP type and the thrust generated by the propeller to be taken up and supporting the main reducer downstream.

As a variant, the front part of the engine can be directly hooked to the aircraft pylon, that is to say without the aid of the bearing box.

In another variant, the intermediate suspension device may include a ball, in particular an elastomeric ball, making it possible to accommodate the relative movements between the pylon and the propeller shaft without generating vibrations on the pylon.

Furthermore, the turboprop engine may also include an intermediate bearing box mounted on the propeller shaft and intended to be fixed to the pylon.

The presence of such an intermediate bearing box can in particular be useful when problems of mechanical strength or a problem of dynamic positioning of the propeller shaft appear. In this way, the diameter and the length of the propeller shaft can be kept.

In addition, the subject of the invention is also, according to another of its aspects, an assembly, characterized in that it comprises:

- a turboprop as defined above,

- a pylon, intended to be fixed to an aircraft wing, for the suspension of the turboprop.

In addition, another subject of the invention is, according to another of its aspects, an aircraft, characterized in that it comprises:

- a turboprop as defined above,

- a wing provided with a front spar and a rear spar forming the wing box,

- a pylon, fixed on the front and rear longitudinal members of the wing, for the suspension of the turboprop.

Advantageously, the attachment of the pylon to the front and rear longitudinal members of the wing of the aircraft makes it possible to better transmit the forces to the structure of the aircraft.

Advantageously, the main reduction gear of the turboprop is mounted to the right or downstream of the front spar of the wing.

In other words, the main reducer of the turboprop can be mounted radially at the level of the front spar of the wing or behind the front spar of the wing.

Also advantageously, such an assembly of the main reduction gear relative to the front spar of the wing makes it possible to transmit the torque of the main reduction gear directly to the structure of the aircraft by means of the pylon, and thus to minimize the mass of the 'aircraft.

Furthermore, the subject of the invention is also, according to another of its aspects, a method for removing the engine from a turboprop engine as defined above, characterized in that it comprises the step consisting in dismantling the engine from the turboprop engine by means of the first and second suspension means while leaving the propeller and the main reduction gear of the turboprop in place.

The turboprop, the assembly, the aircraft and the removal method according to the invention may include any of the characteristics set out in this description, taken in isolation or in any technically possible combination with other characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood on reading the detailed description which follows, of non-limiting examples of implementation thereof, as well as on examining the figures, schematic and partial, of the appended drawing, on which :

FIG. 1 represents, in a side view, an example of a turboprop with a remote power shaft according to a known architecture, and

- Figures 2 and 3 show, very schematically in side views, two embodiments of turboprop engines according to the invention.

Throughout these figures, identical references can designate identical or analogous elements.

In addition, the different parts shown in the figures are not necessarily shown on a uniform scale, to make the figures more readable.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

FIG. 1 has already been described previously in the section relating to the state of the prior art.

With reference to FIGS. 2 and 3, two exemplary embodiments of turboprop engines 1 in accordance with the invention have been illustrated, aiming to explain the attachment of the turboprop engine to an aircraft by suspension from the wing 14 by means of a pylon 13.

The difference between these two exemplary embodiments resides in the fixing of the rear part of the engine (gas generator) of the turboprop 1. Thus, in the exemplary embodiment of FIG. 2, the rear part of the engine is fixed to the part rear of the pylon 13 while in the embodiment of FIG. 3, the rear part of the motor is fixed to the main reduction gear 6.

Thus, the turboprop 1 of the deported shaft type, represented in FIG. 2 or in FIG. 3, comprises a propeller shaft 2 and an engine comprising a gas turbine

3. It should be noted that the engine, that is to say the gas generator, may be of several types, for example of the single-body, double-body, triple-body type, etc. It may include one or more several gas turbines, for example of the free or linked type, and one or more compressors, low pressure and / or high pressure.

The gas turbine 3, also called low pressure turbine, comprises a turbine shaft 4 also called low pressure shaft and extending substantially parallel to the propeller shaft 2. This turbine shaft 4 comprises a rear end coupled to a rear end of the propeller shaft 2 via a main reduction gear 6 also called PGB for the acronym “Power Gear Box”. Upstream of the low pressure turbine 3 is located a high pressure body of the engine, comprising a turbine 16 called a high pressure turbine which directly receives the gases from the combustion chamber of the engine. This high pressure turbine 16 drives a compressor 17 of the high pressure body while being integral in rotation with the latter by means of a shaft 18 called a high pressure shaft. The high pressure body is mechanically decoupled from the low pressure turbine 3, the high pressure shaft 18 and the low pressure shaft 4 not being integral in rotation with one another.

According to the invention, the turboprop 1 further comprises first means of front suspension 10 from the front part of the engine to the front part of the pylon 13 fixed to the wing 14 of the aircraft.

The front part of the engine can be fixed directly to the front part of the pylon 13. As a variant, as shown in FIGS. 2 and 3, the first front suspension means 10 comprise an intermediate suspension device 11, mounted on the propeller shaft 2, as well as a first suspension member 10a from the front part of the engine to the intermediate suspension device 11 and a second suspension member 11a from the intermediate suspension device 11 to the front part of the pylon 13.

Advantageously, this intermediate suspension device 11 makes it possible to resume the thrust and the moment M of the IP type, moment tending to cause the propeller shaft 2 to bend, generated by the propeller 5. It here comprises a gearbox bearings crossed by the propeller shaft 2, serving as a bearing for the rotation of the propeller shaft. The intermediate suspension device 11 can advantageously further comprise flexible studs connecting it to the second suspension member 11a or even also to the first suspension member 10a, making it possible to accommodate the relative movements between the pylon 13 and the propeller shaft 2 without generating vibrations on the pylon 13. As a variant or in addition, the intermediate suspension device 11 could also include an elastomeric ball joint to perform this function.

Furthermore, as shown in Figures 2 and 3, the turboprop 1 may include an intermediate bearing box 15 mounted on the propeller shaft 2 and fixed to the pylon 13. The presence of such an intermediate bearing box 15 may in particular be useful when problems of mechanical strength or a problem of dynamic positioning of the propeller shaft 2 appear. In this way, the diameter and the length of the propeller shaft can be kept without generating undesirable eigenmodes of the propeller shaft.

In addition, in accordance with the invention also, the turboprop 1 also comprises second rear suspension means 12 of the rear part of the engine.

In the embodiment of FIG. 2, which constitutes a preferred embodiment of the invention, the second rear suspension means 12 extend between the rear part of the engine and the rear part of the pylon 13. Thus, the rear part of the engine is fixed to the pylon 13, the second rear suspension means 12 being traversed by the propeller shaft 2. The second rear suspension means 12 can be fixed to the rear part of the engine for example at an annular flange of a low-pressure turbine engine casing, this annular flange can also be used to fix an engine exhaust nozzle.

Furthermore, the turboprop 1 can comprise an accessory box installed for example in the lower part of the engine, in the same way as the accessory box 8 described above concerning the embodiment of FIG. 1.

In the embodiment of FIG. 3, the second rear suspension means 12 extend between the rear part of the motor and the main reduction gear 6, and are fixed for example on a casing structuring the main reduction gear.

Again advantageously, this main reducer 6 is mounted at right or downstream of the front spar of the wing 14, which comprises a front spar and a rear spar on which the pylon 13 is fixed.

Advantageously, such an assembly of the main reducer 6 relative to the front spar of the wing 14 makes it possible to transmit the torque C of the main reducer 6 directly to the structure of the aircraft via the pylon 13, and thus to minimize the mass. of the aircraft.

Thanks to the principle according to the invention of suspending the engine of the turboprop 1 from an aircraft pylon, it is thus possible to do without a suspension cradle and consequently to deposit the engine by means of its suspension means. while leaving at least the propeller and the main reduction gear in place. If an intermediate bearing box 15 is used, it is also possible to leave it at least partially in place, that is to say fixed to the pylon. It may also be advantageous to provide at least one piece of equipment no longer connected to an accessory box mounted on a motor casing, but integrated into or connected to the intermediate bearing box.

15. Such equipment, for example an electric generator or a hydraulic pump, may be left in place when the engine is removed. If an accessory box mounted on an engine casing is kept, it may be less bulky and less heavy due to the transfer of certain equipment to the intermediate bearing box 15. The mass of the engine to be removed will therefore be lightened.

For removing the motor while leaving the main gear 6 in place, a system for uncoupling the turbine shaft 4 from the main gear 5 can be provided for example using a connection disposed at one end of the 'shaft 4 outside the gearbox housing.

The invention thus advantageously allows the design of a high-performance installation of a turboprop of the type with power shaft offset by support of this type of turboprop architecture by means of an aircraft pylon.

Of course, the invention is not limited to the exemplary embodiments which have just been described. Various modifications can be made by those skilled in the art.

Claims (8)

1. Turbopropeller (1) of an aircraft type with propeller shaft (2) offset, comprising a propeller shaft (2) and an engine comprising a gas turbine (3) which comprises a turbine shaft (4) , the latter extending parallel to the propeller shaft (2) and comprising a rear end coupled to a rear end of the propeller shaft (2) by means of a main reduction gear (6), the engine comprising a front part equipped with an air inlet sleeve (7), characterized in that it comprises first means for front suspension (10) of the front part of the engine to a front part of a pylon (13) fixed to a wing (14) of the aircraft and second rear suspension means (12) from a rear part of the engine to a rear part of the pylon (13) and / or to the main reducer (6) . 2. Turboprop according to claim 1, characterized in that the first front suspension means (10) comprise an intermediate suspension device (11), mounted on the propeller shaft (2), a first suspension member (10a ) from the front part of the engine to the intermediate suspension device (11) and a second suspension member (11a) of the intermediate suspension device (11) to the front part of the pylon (13). 3. Turboprop according to claim 2, characterized in that the intermediate suspension device (11) comprises a bearing box through which the propeller shaft (2). 4. Turboprop according to any one of the preceding claims, characterized in that it comprises an intermediate bearing box (15) mounted on the propeller shaft (2) and intended to be fixed to the pylon (13). 5. Set, characterized in that it comprises: - a turboprop (1) according to any one of the preceding claims, - A pylon (13), intended to be fixed to an aircraft wing (14), for the suspension of the turboprop (1). 6. Aircraft, characterized in that it comprises: - a turboprop (1) according to any one of claims 1 to 4, a wing (14) provided with a front spar and a rear spar forming the wing box (14), - a pylon (13), fixed on the front and rear longitudinal members of the wing (14), for the suspension of the turboprop engine (1). 7. Aircraft according to claim 6, characterized in that the main reduction gear (6) of the turboprop engine (1) is mounted to the right or downstream of the front spar of the wing (14). 8. A method of removing the engine from a turboprop (1) according to any one of claims 1 to 4, characterized in that it comprises the step of dismantling the engine of the turboprop (1) by means of the first (10) and second (12) suspension means while leaving in place the propeller (5) and the main reduction gear (6) of the turboprop engine (1). s. 60367 1/2