Device for suspending a casing, a turbine engine and a propulsion assembly

A device for suspending a casing of a turbine engine to the structure of an aircraft is provided. The device includes a suspension ring including a plurality of attachment surfaces positioned so as to protrude on the circumference of the suspension ring and having attachment holes for attachment to the structure; a circumferential flange including a plurality of holes for attaching the suspension ring to the casing; and one or several hanging surfaces for hanging at least one piece of equipment, positioned so as to protrude on the circumference of the suspension ring, and having holes for hanging the piece of equipment to the ring.

FIELD OF THE INVENTION

The invention relates to a device for suspending a casing of a turbine engine to the structure of an aircraft. The invention also relates to a turbine engine and to a propulsion assembly comprising such a device.

PRESENTATION OF THE PRIOR ART

A propulsion assembly comprises a turbine engine, as well as a plurality of systems.

These systems conventionally comprise pieces of equipment to be hung up, such as for example exchangers or hydraulic components.

Now, this hanging proves to be a problem when there exists difficulties for accessing the flanges of the turbine engine.

The flanges of the turbine engine are 360° ferrules used for assembling the different casings of the turbine engine. These flanges form a robust attachment surface for the pieces of equipment.

In the case of suspending the turbine engine at the inter-turbine casing, it is imperative to set into place a suspension ring100surrounding the casing (cf.FIG. 1), in order to distribute the forces over 360° and thereby avoid deformations of the casing.

This inter-turbine casing is conventionally located downstream from the turbine engine, in proximity to the exhaust casing, between two turbines, in particular between the high pressure turbine and the low pressure turbine.

In the particular case of the surface of the inter-turbine casing, access to the flanges may prove to be difficult because of the presence of the suspension ring100.

As schematized inFIG. 1, the suspension ring100is attached onto the circumference of a flange101of the casing.

This attachment has the consequence that the flanges of the casing have reduced accessibility which reduces the number of possible surfaces for hanging the pieces of equipment.

In order to solve the problem of the congestion caused by the attachment of the ring4on the casing2, the prior art solutions require the use of additional supports, added onto the casing2, like the support102illustrated inFIG. 1.

Now, these supports are complex to design and to install.

Further, the presence of additional supports for hanging the pieces of equipment increases the mass of the turbine engine.

PRESENTATION OF THE INVENTION

In order to overcome the drawbacks of the prior art, the invention proposes a device for suspending a turbine engine casing from the structure of an aircraft, characterized in that it comprises a suspension ring, said suspension ring comprising:a plurality of attachment surfaces, positioned so as to protrude on the circumference of the suspension ring and having attachment holes for attachment to the structure,a circumferential flange comprising a plurality of holes for attaching the suspension ring to the casing;one or several hanging surfaces for hanging at least one piece of equipment, positioned so as to protrude on the circumference of the suspension ring, and having holes for hanging the piece of equipment to the ring.

The invention is advantageously completed by the following features, taken alone or in any of their technically possible combination:the hanging surfaces are protruding lugs on the circumference of the ring;the hanging surfaces are positioned facing each other on the upstream circumference of the ring and on the downstream circumference of the ring;one of the hanging surfaces comprises at least two suspension holes for hanging a piece of equipment (case of a “fail-safe” or redundant system);the attachment surfaces are positioned at an azimuth angle comprised between 9 o'clock and 3 o'clock (upper portion of the ring);the suspension ring comprises attachment surfaces both on a upstream circumference of the ring (i.e. along a perimeter of the ring positioned on the upstream side of the latter) and on a downstream circumference (i.e. along a perimeter of the ring positioned on the downstream side of the latter), positioned facing each other;the upstream circumference and the downstream circumference of the ring are separated by a circumferential groove;the upstream and downstream hanging surfaces are positioned facing each other, and define a space between said surfaces able to receive the end of a connecting rod;the hanging surfaces are positioned on the circumference of the ring at an azimuth angle comprised between 3 o'clock and 9 o'clock;the hanging surfaces are positioned on the side opposite to the attachment surfaces.

The invention also relates to a turbine engine comprising at least one casing, comprising at least one flange, one suspension ring, surrounding the casing and attached to the flange of the casing (or to the flanges of adjacent casings), said suspension ring comprising a plurality of attachment surfaces, positioned so as to protrude on the circumference of the suspension ring and having attachment holes, for attachment to a structure of an aircraft, one or several hanging surfaces for at least one piece of equipment positioned so as to protrude on the circumference of the suspension ring, and having holes for hanging a piece of equipment to the suspension ring.

The invention also relates to a propulsion assembly comprising a turbine engine as described earlier, and at least one piece of equipment hung to the suspension ring via a connecting rod attached on a piece of equipment and on at least one hole of a hanging surface.

The propulsion assembly is advantageously completed by the following features, taken alone or in any of their technically possible combination:one of the hanging surfaces comprises at least two holes, the propulsion assembly comprising a piece of equipment hung to the suspension ring via a connecting rod attached onto the piece of equipment and on both holes of the hanging surface, so as to ensure redundancy;the casing comprises a flange adjacent to a flange of another casing of the turbine engine, both flanges comprising a plurality of holes, the suspension ring comprises a circumferential flange comprising a plurality of holes, positioned adjacent to both flanges themselves adjacent to each other, the flange of the ring being attached to the flanges of the casings via attachment tools passing through the holes of the flanges of the casings and of the circumference of the flanges of the suspension ring;the suspension ring comprises a circumferential flange comprising a plurality of holes, positioned between the flanges of adjacent casings, the flanges of the casings comprising a plurality of holes, the flange of the ring being attached to the flanges of the casings, via attachment tools passing through the holes of the flanges of the casings and of the circumferential flange of the suspension ring;the propulsion assembly further comprises a connecting rod for load spreading attached to the piece of equipment hung to the suspension ring, and to the casing;the connecting rods have an end attached to the structure and the other end received between the upstream and downstream attachment surfaces of the ring.

The invention thus provides a simple and efficient solution for hooking up the pieces of equipment on the turbine engine.

No additional part is required. The mass of the assembly is therefore reduced. Further, the hooking-up surfaces are immediately accessible.

DETAILED DESCRIPTION

A device1for suspending a turbine engine3from the structure12of an aircraft as well as the setting of the place of this device1around a casing2is illustrated inFIGS. 2 and 3.

A propulsion assembly24comprising the turbine engine3, the device1for suspending a turbine engine from the structure12, and a piece of equipment15hung to the device1is illustrated inFIG. 13.

The structure12from which the turbine engine is suspended is commonly called the cradle of the aircraft. The cradle conventionally comprises frames connected through connected rods.

The casing2on which the device1is set into place is for example a casing positioned downstream following the turbine engine3, called the inter-turbine casing. This is a casing positioned between two turbines, in particular between the high pressure turbine and the low pressure turbine.

The casing2is conventionally an axisymmetrical part, the outer cover of which is ring-shaped. The center of the casing2consists of an aperture. The outer cover of the casing2ends with at least one attachment flange20(cf.FIG. 14).

This is a circumferential flange20extending over the external perimeter of the casing2. This flange20is attached to another flange29of the same type belonging to another adjacent casing25of the turbine engine3.

The turbine engine3comprises a succession of adjacent casings attached to each other (FIG. 13).

As explained subsequently, the flanges20,29may be adjacent, or receive between them a flange of the suspension device1.

The flanges20,29of the casings2,25each comprise a plurality of holes30facing them allowing attachment tools to be passed through them.

As illustrated inFIG. 3, the device1comprises a suspension ring4.

The ring4comprises a wide aperture in its center giving the possibility of surrounding the casing or the casings onto which the ring4is attached (FIG. 4).

The suspension ring4comprises a circumferential flange5which extends towards the inside of the ring4and covers at least one portion of the internal circumference of the ring4. The flange5is therefore at least partly ring-shaped.

The circumferential flange5comprises a plurality of holes35for attaching the ring4to at least one casing of the turbine engine.

In order to ensure the attachment of the ring4to the structure12of the aircraft, the suspension ring4comprises a plurality of attachment surfaces33, positioned so as to protrude on the circumference of the ring4.

The attachment surfaces33are for examples protruding lugs, each comprising at least one attachment hole6(cf.FIG. 4). They may also assume the shape of yokes or extensions of any protruding shape on the circumference of the ring4.

Alternatively, the attachment surfaces33may belong to a continuous perimeter. However, distinct surfaces33are preferable in order to reduce the mass.

They are conventionally positioned at an azimuth angle comprised between 9 o'clock and 3 o'clock (upper portion of the ring4).

Generally, the suspension ring4comprises attachment surfaces33both on a upstream circumference13of the ring4(i.e. along a perimeter of the ring4positioned on the upstream side of the latter) and on downstream circumference14(i.e. along a perimeter of the ring4positioned on the downstream side of the latter), positioned facing each other. According to a possible embodiment of the ring4, the upstream circumference13and the downstream circumference14of the ring4are separated by a circumferential groove23(cf.FIG. 5).

The suspension of the ring4from the structure12of the aircraft may be implemented via connecting rods27(cf.FIG. 3), one end of which is attached to the structure12and the other end is received between the upstream and downstream attachment surfaces33of the ring4. Screws crossing the attachment holes6and complementary holes present on the end of the connecting rods27give the possibility of ensuring attachment.

The suspension ring4further comprises one or several hanging surfaces10for at least one piece of equipment15, positioned so as to protrude on the circumference of the ring4.

By piece of equipment15is meant independent elements of the turbine engine which require being attached onto the latter. These are for example, exchangers or hydraulic components or other components, depending on the cases.

The hanging surfaces10have holes8for hanging the piece of equipment15to the ring4(cfFIG. 5).

Thus, by the hanging surfaces10, the piece of equipment15is directly hung onto the ring4.

In the exemplary embodiment ofFIG. 3, the ring4extends radially, and the hanging surfaces10also extend radially, in parallel or in the plane of the ring4.

The hanging surfaces10are for example protruding lugs on the circumference of the ring4or protruding yokes. They may also assume the form of extensions of any protruding shape on the circumference of the ring4.

It is possible that the hanging surfaces10be contiguous, but it is preferable that they be distinct in order to reduce the mass.

Thus, the piece of equipment15may be hung to the ring4via a connecting rod36attached on the piece of equipment15and on at least one hole8of a hanging surface10. On the side of the piece of equipment15, the connecting rod36may notably be attached onto yokes32of the piece of equipment15(cf.FIG. 3).

According to a possible embodiment, the hanging surfaces10are positioned on the upstream circumference13of the ring and on the downstream circumference14of the ring4. The upstream and downstream hanging surfaces10are positioned facing each other and therefore define a space between said surfaces10with which the end of the connecting rod36may be received.

The attachment is for example ensured via screws (or other attachment tools) passing through the holes8of the hanging surfaces10facing each other, and via holes present on the corresponding end of the connecting rod36.

According to the exemplary embodiment illustrated inFIG. 5, the hanging surfaces10are positioned on the circumference of the ring4at an azimuth angle comprised between 3 o'clock and 9 o'clock, which allows the piece of equipment15to be suspended to the ring4. In this casing, the hanging surfaces10are positioned on the side opposite to the attachment surfaces33.

In order to ensure the redundancy of the hanging, of the “fail safe” type, according to an embodiment, it is provided that one of the hanging surfaces10comprises at least two holes8for hanging a piece of equipment15(seeFIG. 4). In this case, the hanging surface10on the upstream circumference and the facing hanging surface10on the downstream circumference each comprise at least two holes8facing each other, as illustrated in the figures.

Thus, by means of these two holes8present on a same hanging surface10, the connecting rod36connecting the piece of equipment15to the hanging surface10is attached to at least two locations which reinforce the safety of the hanging by redundancy.

This is illustrated inFIG. 3, in which the piece of equipment15is hanging to the ring4via a connecting rod36attached onto the piece of equipment15and on both holes8of the hanging surface10, in this case on the upstream and downstream hanging surfaces10of the ring4.

According to an embodiment, illustrated inFIG. 3, a load-spreading connecting rod31is attached to the piece of equipment15hung to the ring4on the one hand and to the casing2on the other hand. This connecting rod31gives the possibility of spreading the loads along the engine axis, in order to avoid swinging of the piece of the equipment15.

An embodiment of the attachment of the ring4to casings of the turbine engine is illustrated inFIGS. 7 to 11.

As illustrated in these figures, the circumferential flange5of the ring4will be attached against both adjacent flanges20,29of the adjacent casings2,25.

Thus, the circumferential flange5is adjacent to one of the flanges20of a casing2, this flange20of a casing2being itself adjacent to the flange29of another casing25.

The attachment of the flange5against these flanges20,29is ensured via attachment tools (for example screws) passing through the holes of the flanges20,29of the casings and of the circumferential flange5of the ring1.

InFIGS. 10 and 11, the ring4thus surrounds the casing2and is attached to the casing2and to the adjacent casing25as described earlier.

According to another embodiment, illustrated inFIG. 12, the circumferential flange5of the ring4is positioned between the flange29of the casing2and the flange20of the other adjacent casing25. The flange5is therefore inserted between the flanges20and29.

The attachment of the flange5between these flanges20,29is ensured via attachment tools (for example screws) passing through the holes of the flanges20,29of the casings2,25and of the circumferential flange5of the ring1.

The suspension device1applies to any type of propulsion assemblies.

In particular it applies to propulsion assemblies comprising small size turbine engines, insofar that this type of turbine engine has more reduced hanging surfaces for pieces of equipment. It is therefore necessary to optimize at best the hanging of the pieces of equipment.

FIGS. 15 to 18compare the dimensions of a large size nacelle (FIG. 17) with a small size nacelle (FIG. 15), as well as the respective dimensions of a piece of standard equipment specific to each nacelle (FIGS. 16 and 18). The dimensions (in meters) illustrated in the figures are summarized in the table below. These dimensions are approximate and provided as a non-limiting example.

WHDNacelle of FIG. 151.151.64Piece of equipment of FIG. 160.510.160.16Nacelle of FIG. 171.62.26.4Piece of equipment of FIG. 180.620.330.16

On a large size turbine engine, the width of the nacelle is of about 1.6 m, and the width of the pieces of equipment3installed is of about 0.62 m, i.e. a ratio of 0.39.

On a small size turbine engine, the width of the nacelle is of about 1.15 m, and the width of the piece of equipment to be installed is of about 0.51 m i.e. a ratio of 0.44.

Thus, for a turbine engine of smaller size, the congestion induced by the pieces of equipment is larger.

Further, turbine engines of smaller sizes generally have reduced hooking-up surfaces.

The invention, as for it, gives the possibility of optimizing the hooking-up of pieces of equipment relatively to the available space.