Rear engine mounting structure

Abstract

A rear engine mounting structure for connecting an engine system to an aircraft structure, the rear engine mounting structure comprising: an elongate body having a first end arranged, in use, for connection to a rear side of a turbine exhaust casing, the elongate body comprising one or more mounting points for connection to the aircraft structure, wherein the one or more mounting points are spaced apart from the first end in an axial direction.

Description

Technical Field

[0001] The present invention particularly, but not exclusively, relates to engine mounting devices for connecting engine systems (such as gas turbine engines) to aircraft structures. Background Technology

[0002] In conventional engine systems used in aircraft (such as gas turbine engines), each engine is typically structurally connected to the aircraft wing via a front engine mount, a rear engine mount, and a pylon. These mounts (in combination with the pylons) support the weight of each engine and additionally provide a path for transferring thrust from the engine to the aircraft during taxiing and flight. Thrust linkages can also be used, which further connect the engine to the pylon.

[0003] Traditional engine mount arrangements are extremely reliable and robust, and are used in various forms for different engine and aircraft configurations and combinations. Engine mount arrangements are typically statically determined, and therefore provide a simple load pattern between the engine and the aircraft that is not significantly altered by deformation caused by loads or temperature differences. To maintain this statically determined characteristic, additional mounting points cannot be added to the existing mount system unless they are mechanically ineffective or redundant during normal use, for example, through the gap between the pin and the oversized hole associated with the mounting point.

[0004] However, changing environmental requirements in the aerospace industry have led to changes in engine fuels and operating characteristics. To meet new emission requirements, additional auxiliary equipment is needed both within the aircraft structure and the engine system itself, making both the engine and the aircraft more complex. This, in turn, has increased the complexity of the interconnections between the aircraft and the engine.

[0005] The inventors have established an alternative method for engine mounting that allows some of the most complex emission technologies to be used in conjunction with engine systems, such as gas turbine engines, as described above. More specifically, the inventors have established an engine mounting method that allows additional auxiliary equipment to be easily integrated into the engine system. Summary of the Invention

[0006] Specific aspects and embodiments of the invention are set forth in the appended claims.

[0007] From a first perspective, a rear engine mounting structure for connecting an engine system to an aircraft structure is provided, the rear engine mounting structure comprising: an elongated body having a first end arranged for connection in use to a rear side of a turbine exhaust casing, the elongated body including one or more mounting points for connection to the aircraft structure, wherein the one or more mounting points are spaced apart from the first end in an axial direction.

[0008] Therefore, unconventionally, the rear engine mounting structure described herein provides a support structure with a rear engine mount (or lug) that is moved rearward (compared to conventional arrangements) and positioned behind the engine in the airflow direction. This arrangement is generally highly undesirable due to interference from exhaust gases from the rear or rear of the turbine exhaust casing. However, the modified support structure as described herein offers numerous technical advantages that can be used to allow new emission technologies to be incorporated into the engine system.

[0009] For example, the further rearward movement of the engine mounts (compared to conventional arrangements) allows for additional space or volume for auxiliary equipment. More specifically, this support structure behind the turbine allows for the integration of additional components into the engine system while maintaining the engine system's center of gravity between the engine mounts and without adversely affecting the load distribution of the engine system on the engine mounts. For example, it reduces shear and torsional loads on the engine mounts (especially the rear engine mounts). This increases the lifespan of the engine mounts and reduces the likelihood of component failure, thereby increasing the overall safety of the aircraft. It also allows for lighter and more compact designs for the mounts and attachment structures while maintaining the static deterministic characteristics of the engine mount arrangement.

[0010] Furthermore, as described in more detail below, the support structures described herein allow for the control and guidance of exhaust flow exiting the turbine exhaust casing in a specific manner. For example, the rear engine mounting structure can provide a gas-permeable structure through which exhaust from the TEC / turbo can flow. Airflow surfaces arranged within the mounting structure can advantageously allow for specific exhaust flow paths depending on the auxiliary equipment used in the engine.

[0011] In one example, additional components such as heat exchangers can be positioned behind the turbine without adversely affecting the load distribution of the engine system on the engine mount, and without placing a very large amount of load on the engine mount. As discussed above, this reduces, for example, shear and torsional loads on the engine mount, particularly the rear engine mount.

[0012] Furthermore, by providing a rear engine mounting structure to structurally support and bear the weight / load of the additional component, the additional component does not need to provide its own structural and load-bearing support. For example, the additional component may not have adequate rigidity or resistance to torsional loads that it must bear on its own. Therefore, the rear engine mounting structure is able to respond to loads associated with the additional component, rather than the additional component itself responding to these loads or forces.

[0013] In this way, the rear engine mounting structure allows for optimized additional components because the load-bearing requirements of the additional components are decoupled from the additional components themselves. This increases design flexibility and layout compatibility by reducing the need for structural modifications to the additional components.

[0014] The first end of the rear engine mounting structure can be arranged as an inner or outer ring for connection to the turbine exhaust casing (TEC) during use. In some examples, these can be the inner and outer flanges of the TEC, respectively. Therefore, the rear engine mounting structure provides a load path between the aircraft structure and the structural portion of the TEC. This allows the structure to respond to loads on the structure and on additional components that may be connected to or supported by the structure during use.

[0015] The extended body of the rear engine mounting structure may also include a surrounding annulus that provides one or more mounting points and includes one or more radially inwardly extending struts that connect the surrounding annulus to a portion of the extended body.

[0016] This arrangement of annular sections with radially extending struts increases structural strength and advantageously distributes loads circumferentially. This reduces the load that can be placed beneath each component or each region of a component, thus increasing component life. The annular sections also allow turbine exhaust to pass through the struts and between them, thereby minimizing airflow disturbance.

[0017] The elongated body may further include an inner annular portion disposed between the elongated body and the surrounding annular portion, wherein the strut connects the surrounding annular portion to the portion of the elongated body via the inner annular portion.

[0018] In other words, two concentric ring sections can be arranged around the elongated body, and struts can connect the two ring sections to each other and connect the inner ring section to the elongated body. This arrangement further increases the structural strength. Vibration and shear / torque loads can also be decoupled from each other between the struts of the two ring sections.

[0019] In some examples, the circumferential spacing between two different pairs can be different. For example, to save weight, the upper half of the annular section may have a greater number of struts than the lower half.

[0020] The rear engine mounting structure may also include one or more radially spaced and axially extending beams. These beams can extend forward and backward from the surrounding annulus. By providing axially extending beams, the bending stiffness of the structure is greatly increased.

[0021] One or more supports may include internal channels (or conduits) for communicating fluid. In use, the internal channels may be arranged to connect to additional components, thus providing an integral and space-efficient way to provide the fluid passage that the additional components may require.

[0022] In some examples, the surrounding annulus may be in the form of a mesh or grid structure to provide structural rigidity while allowing exhaust gas to flow through and out of the structure. For example, the structure may include one or more perforations, such as cuts or holes. These perforations reduce the weight of the surrounding annulus and allow gas flow. Peripheral flanges may be provided on the surrounding annulus to further increase rigidity.

[0023] In some examples, the elongated body may include a surrounding annulus that provides one or more mounting points connected to one or more axially extending beams that connect a portion of the elongated body at its first end to a portion of the elongated body at its second end opposite to the first end.

[0024] In this arrangement, the columns are omitted, and the axially extending beams provide bending stiffness to the structure. This allows for a weight-reduced arrangement while still providing sufficient stiffness and load-bearing characteristics.

[0025] The portions of the elongated body at its first and second ends can be radially extending sections, such as radially extending discs. These portions connect to axially extending beams at the front and rear ends of the elongated member and provide further strength and stiffness to the structure.

[0026] In some examples, the one or more mounting points can be disposed on the surface of the elongated body. The mounting points (also called mounting lugs) can be directly disposed on the surface of the elongated body. This allows for efficient fabrication of the structure.

[0027] In some examples, the elongated body may be tapered or conical. This shape reduces interference with turbine exhaust and provides an aerodynamic profile to reduce drag. In some examples, the elongated body may be flared. This directs the airflow from the turbine radially, for example, through the use of additional components, which may be advantageous in some arrangements (e.g., where the additional component is a heat exchanger).

[0028] In some examples, the elongated body may include multiple beams forming a mesh structure. The mesh structure provides stiffness and increased strength to the rear engine mount structure while maintaining weight efficiency. Optionally, the multiple beams may include axial beams and transverse beams, such as axial beams and diagonal cross braces. This elongated, cage-like mesh structure allows air to pass through it, thereby minimizing its interference with the airflow from the turbine.

[0029] In some examples, the elongated body may include a plate and a central structure positioned at a second end opposite the first end of the elongated body. The central structure is attached to the plate and arranged to connect to the inner flange of the turbine exhaust housing in use. By doing so, a second load path is provided through the plate, the central structure, and the inner flange of the TEC.

[0030] By providing multiple load paths, the rear engine mounting structure can effectively distribute loads throughout the structure, thereby reducing the load experienced by each individual component. This increases the overall lifespan of the mounting structure and allows for a reduction in the weight of each individual component, as each component is required to bear a reduced amount of load.

[0031] In some examples, the elongated body has a polygonal or annular cross-section. This provides an efficient load-bearing structure whose weight can be minimized while meeting mechanical requirements. It also provides an aerodynamic profile to minimize airflow interference from turbine exhaust.

[0032] In some examples, the elongated body is the exhaust cone of the turbine's rear structure. This intuitively transforms the cone into a load-bearing structural part that can be used to support the loads of additional components.

[0033] In some examples, the mounting point can be positioned on a mounting ring that circumferentially surrounds the elongated body. By placing the mounting point on a reinforced mounting ring, the load can be distributed more evenly around the rear engine mounting structure, thus helping to reduce load "hot spots" and increase the lifespan of structural components.

[0034] In some examples, the mounting ring is circular or polygonal. Therefore, the mounting ring is used to transfer loads to the elongated body. In examples where the mounting ring is polygonal, the mounting points can be set at the vertices of the polygonal mounting ring. These points are typically the strongest points of the polygonal ring, making them ideal as fixing points for mounting.

[0035] In some examples, the elongated body may include a rear ring at a second end opposite to the first end. The rear ring increases the rigidity of the structure.

[0036] In some examples, the elongated body is approximately cylindrical. This arrangement is aerodynamically efficient and optimized for the shape of the TEC. The internal volume can be used to accommodate additional components during use, or the external surface can be used to support additional components during use.

[0037] To reduce the weight of the structure and allow venting to flow across the surface of the elongated body, in some examples, the elongated body may have perforations on its surface. These perforations can be in the form of circular, triangular, square, hexagonal, etc. Advantageously, the perforations can be triangular with rounded corners, as these can be manufactured using efficient milling processes.

[0038] To reduce weight, in some examples, the elongated body may include an equal grid arrangement. This arrangement reduces weight as material is cut from the surface, but still provides strength and stiffness due to the raised lines between the cuts.

[0039] In some examples, mounting points are located on the surface of the elongated body or on a mounting ring that circumferentially surrounds the elongated body. By providing mounting points on the surface of the elongated body, manufacturing is simplified, and by providing mounting points on a mounting ring, loads can be distributed more evenly throughout the structure.

[0040] In some examples, the number of mounting points is three. The inventors have identified three as the optimal number for covering shared loads across the structure and for providing redundancy in the event of component failure.

[0041] In some examples, one of the mounting points includes an oversized hole. This hole is too large for a pin or bolt, and is configured to receive the pin or bolt during use. Therefore, this mounting point only functions to transfer loads if one or more of the other mounting points / links fail. This arrangement provides redundancy and increases safety in the event of component failure.

[0042] In some examples, the mounting ring may include one or more perforations, such as cutouts or holes. These perforations facilitate radial outward airflow from the turbine. Peripheral flanges may be provided on the mounting ring to further increase rigidity.

[0043] From the above description and the teachings of this document, it will be understood that the rear engine mount provides a gas-permeable structure through which exhaust gas from the TEC can flow. The airflow surfaces arranged within the mount can advantageously allow for specific exhaust flow paths depending on the auxiliary equipment used in the engine. For example, one or more heat exchangers can be incorporated into or around the engine mount, and exhaust gas can be directed into, around, or through such heat exchangers. Therefore, the mount can be incorporated with means to orient exhaust gas toward and guide it through one or more heat exchangers, providing structural support for the heat exchangers. Other configurations can also be implemented using the mount described herein.

[0044] In some examples, the engine system can be a gas turbine engine.

[0045] From a second perspective, a rear engine mounting structure for connecting an engine system to an aircraft structure is provided, the rear engine mounting structure comprising: an annular body including one or more mounting points for connecting to the aircraft structure; and one or more radially inwardly extending struts connecting the annular body to an elongated central body, the first end of the elongated central body being arranged to be connected in use to the rear side of a turbine exhaust casing of the engine system.

[0046] Therefore, in a similar manner to the first aspect, additional components (such as heat exchangers) can be positioned behind the turbine without adversely affecting the load distribution of the engine system on the engine mount, and without imposing a very large load on the engine mount. For example, shear and torsional loads on the engine mount, particularly the rear engine mount, are reduced. This increases the lifespan of the engine mount and reduces the likelihood of component failure, thereby increasing the overall safety of the aircraft.

[0047] From a third perspective, a method for connecting an engine system to an aircraft structure is provided, the method comprising: providing a rear engine mounting structure of any of the embodiments described in this example; connecting a first end to the rear side of the turbine exhaust casing of the engine system; and connecting the one or more mounting points to the aircraft structure.

[0048] Therefore, the engine system can be connected to the aircraft structure in a manner that allows for the integration of additional components behind the turbine, without adversely affecting the load distribution of the engine system on the engine mounts or applying excessive loads to the engine system components.

[0049] From a fourth perspective, an aircraft is provided that includes any of the rear engine mounting structures described in this example.

[0050] Other aspects will also become apparent from reading this disclosure, particularly from the brief description of the accompanying drawings, the detailed description, and the claims. Attached Figure Description

[0051] Examples of this disclosure will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 The engine system and the conventional arrangement for connecting the engine system to the aircraft structure are shown.

[0052] Figure 2 It shows the relationship with Figure 1 The engine system layout is similar to that of the TEC, but with additional components located behind the TEC.

[0053] Figure 3 A rear engine mounting structure according to the invention described herein is shown.

[0054] Figure 4a and Figure 4b A side sectional view and an end view (rear view) of the rear engine mounting structure according to the invention described herein are shown.

[0055] Figure 5a and Figure 5b An end view (rear view) of the rear engine mounting structure according to the invention described herein is shown.

[0056] Figure 6a , Figure 6b and Figure 6c A side sectional view, an end view (rear view), and an end view (rear view) of the rear engine mounting structure according to the invention described herein are shown respectively.

[0057] Figure 7 A rear engine mounting structure according to the invention described herein is shown.

[0058] Figure 8a and Figure 8b A side sectional view and an end view (rear view) of the rear engine mounting structure according to the invention described herein are shown.

[0059] Figure 9 A rear engine mounting structure according to the invention described herein is shown.

[0060] Figure 10a and Figure 10b A side sectional view and an end view (rear view) of the rear engine mounting structure according to the invention described herein are shown.

[0061] Figure 11a and Figure 11b A side sectional view and an end view (rear view) of the rear engine mounting structure according to the invention described herein are shown.

[0062] Figure 12a and Figure 12b A side sectional view and an end view (rear view) of the rear engine mounting structure according to the invention described herein are shown.

[0063] Any reference to prior art documents in this specification should not be construed as an admission that such prior art is widely known or forms part of common general knowledge in the art. As used herein, the words “comprising,” “including,” and similar terms should not be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to.” The invention is further described with reference to the following examples. It should be understood that the claimed invention is not intended to be limited in any way by these examples. It will also be appreciated that the invention covers not only individual embodiments but also combinations of embodiments described herein.

[0064] The various embodiments described herein are presented merely to aid in understanding and teaching the claimed features. These embodiments are provided only as representative examples of embodiments and are not exhaustive and / or exclusive. It should be understood that the advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein should not be considered as limitations on the scope of the invention as defined by the claims or on its equivalents, and other embodiments may be utilized and modifications may be made without departing from the spirit and scope of the claimed invention. In addition to those specifically described herein, various embodiments of the invention may suitably include, constitute, or substantially constitute suitable combinations of, the disclosed elements, components, features, parts, steps, devices, etc. Furthermore, this disclosure may include other inventions not currently claimed but which may be claimed in the future. Detailed Implementation

[0065] Figure 1 The diagram illustrates engine system 1 and a conventional arrangement for connecting engine system 1 to aircraft structure 2. In this example, engine system 1 is a gas turbine engine with components conventionally associated with gas turbine engines. Engine system 1 includes a fan casing 4 and a turbine exhaust casing (TEC) 6. TEC 6 forms the outer shell of the turbine rear structure (TRS).

[0066] like Figure 1 As shown, engine system 1 is attached to aircraft structure 2, such as a wing pylon, via one or more front engine mounts 3, one or more rear engine mounts 5, and one or more thrust linkages 7. Aircraft structure 2 may alternatively be part of the aircraft fuselage itself, such as the aft fuselage or in a blended wing body arrangement. These mounts (also called lugs) and linkages distribute and transfer the load of engine system 1 to aircraft structure 2. More specifically, in a conventional arrangement, engine system 1 is connected to aircraft structure 2 via front engine mounts 3 mounted on fan housing 4 and rear engine mounts 5 mounted on TEC 6.

[0067] TEC 6 includes an inner ring 9 having an inner flange 12 or an inner ring portion 12, and an outer ring 10 having an outer flange 11 or an outer ring portion 11. In some arrangements, the cone may be centrally located at the TEC.

[0068] Engine system 1 has a composition of Figure 1 The central axis, indicated by the dashed line 13, extends axially through the center of engine system 1. Also... Figure 1 As shown, the center of gravity of engine system 1, marked CoG, is axially located between the front engine mount 3 and the rear engine mount 5. Also marked, "rearward" refers to components located further downstream in the airflow direction during use. For example, air enters at the front of engine system 1 and exits at the rear of engine system 1 via a turbine.

[0069] Figure 2 It shows the relationship with Figure 1 The engine system arrangement is similar to engine system arrangement 1, but with an additional component 14 located behind (or downstream in the airflow direction during use) the TEC 6. As discussed herein, in some engine system arrangements, it may be advantageous to arrange the additional component (e.g., a heat exchanger) behind the TEC 6. If the additional component (e.g., a heat exchanger) is located behind or downstream of the TEC 6 or the turbine in the exhaust direction, the load distribution of engine system 1 on engine mounts 3, 5 can be significantly altered.

[0070] This is indicated by the center of gravity CoG, which was previously located between the front engine mount 3 and the rear engine mount 5, but is now located behind or behind the rear engine mount 5. As the inventors have identified, this changed load distribution of the engine system on the engine mounts applies significant and varied loads to the engine mounts. This increased load, particularly on the rear engine mount, can lead to uneven or increased wear on the engine mounts, thereby reducing component life. Furthermore, this increased and rearward-distributed load increases the shear and torsional loads on the components of the engine system 1, which may increase the likelihood of component failure. This reduces the overall safety of the aircraft.

[0071] Turning Figure 3 The rear engine mounting structure 15 according to the invention described herein is shown.

[0072] As shown in the figure, the rear engine mounting structure 15 includes an extended body 16. The extended body 16 of the rear engine mounting structure 15 is arranged in use for connection at a first end to the rear side of the TEC6 (or TRS). For readability, the remaining portion of the engine system 1 in front of the TEC6 is not shown. The extended body 16 may be arranged in use to connect at its first end to the inner flange 12, outer flange 11, or both or other portions of the TEC6. Alternatively, the extended body 16 may be arranged in use to connect to the radially inner or radially outer surface or portion of the TEC6 or TRS. By arranging the first end as a portion connecting to the TEC6, the footprint of the rear engine mounting structure 15 is minimized, and therefore aerodynamic interference is reduced.

[0073] The elongated body 16 is arranged to accommodate, be directly or indirectly connected to, or otherwise support the additional component 14 in use, which in some examples is a heat exchanger. For example, the elongated body 16 may be provided with one or more connection points for connecting the additional component 14. The additional component 14 may be accommodated by the elongated body 16 in use, or it may be structurally supported by the elongated body 16.

[0074] The rear engine mounting structure 15 includes one or more mounting points 5 (corresponding to one or more rear engine mounts) disposed on the extended body 16. The mounting points 5 described herein may be lugs or portions having through holes for receiving bolts or pins; however, it should be understood that other techniques may be used. As shown, the mounting points 5 are connected to the aircraft structure 2 via linkages and pins. The mounting points 5 may be integrally formed with the extended body 16.

[0075] and Figure 1 and Figure 2 In contrast, mounting point 5 is moved from TEC 6 and instead positioned on the extended body 16 of the rear engine mounting structure 15. In other words, the rear mounting point 5 is moved to the rear of TEC 6 and spaced apart from the rear of TEC 6 or TRS in the axial rearward direction. Thus, mounting point 5 and TEC 6 are positioned on different and axially separated planes that intersect perpendicularly to the axial direction of engine system 1.

[0076] Due to the altered position of the rear engine mount 5, the center of gravity CoG of the engine system 1 (including the additional component 14) is located between the front engine mount 3 (not shown) and the rear engine mount / mounting point 5. This reduces the adverse effects of the varying load distribution on the engine system on the engine mounts and the center of gravity located behind the rear engine mounting point. For example, the varying loads on the engine mounts are reduced. In particular, due to this arrangement, shear and torsional loads on the engine mounts (especially the rear engine mount) are reduced. This increases the lifespan of the engine mounts and reduces the likelihood of component failure, thereby increasing the overall safety of the aircraft. Furthermore, this structure allows for a lightweight and compact implementation.

[0077] Furthermore, by providing the rear engine mounting structure 15 to structurally support and bear the weight / load of the additional component 14, the additional component 14 does not need to provide its own structural and load-bearing support. In fact, in some examples where the additional component 14 is a heat exchanger, the rear engine mounting structure 15 can provide the necessary structural support instead of providing structural support within the heat exchanger that reduces its functional volume. In this way, the rear engine mounting structure 15 allows for optimized additional components because the load-bearing requirements of the additional component are decoupled from the additional component itself. This increases layout flexibility and compatibility by reducing the need for structural modifications to the additional component.

[0078] Furthermore, in some examples, the additional component 14 may not be adequately rigid or resistant to the torsional loads it is to bear. Therefore, the rear engine mounting structure 15 responds to the loads associated with the additional component 14, rather than the additional component 14 itself responding to these loads or forces. This further allows the additional component 14 to be optimized for its intended purpose, such as heat exchange, without needing to meet structural and strength requirements to support its own loads.

[0079] like Figure 3 As shown, one or more mounting points 5 are disposed on the surface of the elongated body. Alternatively, a mounting ring may be provided that circumferentially surrounds the elongated body and provides a reinforcing ring in which the mounting points 5 can be located. This provides increased strength and further distributes the load throughout the rear engine mounting structure 15. For example, the mounting ring causes the load to be distributed circumferentially throughout the elongated body 16.

[0080] Turning Figure 4a and Figure 4b These figures illustrate additional rear engine mounting structures according to the invention described herein.

[0081] As shown in the figure, the rear engine mounting structure 15 includes an elongated body 16, which in this example is a tapered or tapered elongated body. Alternatively, the elongated body 16 may be generally cylindrical or flared. The elongated body 16 is centered on the axis of the engine system (previously shown by dashed line 13) and extends axially behind the TEC 6 or TRS.

[0082] The tapered or tapered elongated body 16 reduces the aerodynamic footprint of the rear engine mounting structure 15 and helps guide the airflow exhausted from the rear of the turbine. Furthermore, the tapered or tapered elongated body 16 reduces airflow interference from the turbine exhaust, resulting in increased thrust. A flared elongated body 16 can help guide the turbine exhaust airflow radially.

[0083] Furthermore, in some examples, the inventors have established that the exhaust cone of the TRS can be adapted counterintuitively to the conical elongated body of this arrangement.

[0084] For example, in some engine systems, it is known to provide an exhaust cone centered on TEC 6. However, traditionally, these exhaust cones do not perform load-bearing purposes but are based on airflow considerations. In fact, it is counterintuitive to modify the exhaust cone or structure behind TEC 6 to interfere with airflow by including mounting points 5 for connecting the cone or structure to the aircraft structure 2.

[0085] Furthermore, as shown in the figure, the elongated body 16 is arranged to be substantially circumferentially surrounded by the attachment 14 during use. This can help to further reduce the overall footprint of the rear engine mounting structure 15. This can also help guide airflow through the attachment 14, which can be particularly advantageous in examples where the attachment 14 is a heat exchanger.

[0086] The elongated body 16 can be configured to connect to or otherwise support the attachment 14 in use. For example, one or more struts can be provided that project radially outward from the elongated body 16. The surfaces of these struts, or in fact the elongated body 16 itself, can be arranged for connection to the attachment 14 or sections thereof.

[0087] Aircraft structure 2 can be a wing pylon or part of the aircraft fuselage itself. In use, the extended body 16 of the rear engine mounting structure 15 is connected at its first end (the front end of the rear engine mounting structure 15) to the rear side of the turbine exhaust casing (TEC) 6. As described above, this connection can be made by one or more bolts to secure the extended body 16 to the interior of the TEC 6, such as an inner flange or an engine outlet inner flange. The extended body 16 may include a flange at its first end to facilitate connection to the TEC 6 and provide additional surfaces through which the connection can be made. Other connection arrangements are possible. In some examples, the extended body may be welded to the TEC inner shell / inner ring, or the extended body may be integrally formed with the TEC hub / inner shell / inner ring and thus manufactured as a single piece.

[0088] As described above, the rear engine mounting structure 15 includes one or more mounting points 5 for connection to the aircraft structure 2. For example, the extended body 16 includes mounting points 5. This connection is shown as formed via a link and a pin inserted through the end of the link, and a hole in the mounting point 5. It should be understood that other forms of link arrangement may be used.

[0089] like Figure 4a As shown, mounting point 5 is spaced apart from the first end (arranged to connect to TEC 6 in use) in the axial direction of the elongated body 16. In some examples, mounting point 5 may be placed in the central region of the elongated body 16, such as the axial central region, and then the elongated body 16 of the engine mounting structure 15 is connected to TEC 6 at its end.

[0090] Mounting point 5 in this arrangement transmits vertical forces. Therefore, in addition to the transmitted lateral, vertical, and thrust forces, the front engine mount (not shown) also transmits torque and lateral loads around the vertical axis. The linkage for attaching to mounting point 5 may include a ball bushing to minimize torque transmission, thereby increasing component life. A second mounting point may be added for redundancy, wherein the second mounting point may include an oversized bore (configured to receive the pin relative to it). This arrangement provides redundancy and increases safety in the event of component failure.

[0091] like Figure 4a As further shown, the additional component 14 (e.g., a heat exchanger) can be arranged at the rear of the TEC 6. Although not shown, the rear engine mounting structure can support the weight and load of the additional component 14. As mentioned above, this weight or load can be transferred via various connections (e.g., one or more connecting struts), or the additional component 14 can be directly attached to the extended body 16 of the rear engine mounting structure. In this way, the rear engine mounting structure 15 can be configured to connect to the heat exchanger in use or to support the weight of the heat exchanger in use.

[0092] Although the attachment 14 is shown as being arranged radially around the elongated body 16, it should be understood that the attachment 14 may extend to various amounts of the length of the rear engine mount structure 15 and the elongated body 16. In some examples, the attachment 14 may extend the entire length of the elongated body 16 of the rear engine mount structure 15.

[0093] The load path of this arrangement will now be described. In conventional systems, the rear engine mount is located on TEC6, as described above. However, in this arrangement, the rear engine mount (mounting point 5) is moved to the rear of TEC6. The load path from aircraft structure 2 passes through the linkage to mounting point 5 of the rear engine mount structure 15. The load at mounting point 5 is reflected in the rear engine mount structure 15. The load path continues through and along the extended body 16 of the rear engine mount structure, and then connects to the rear side of TEC6. Therefore, the extended body 6 (e.g., the cone of a TRS or an exhaust cone) is the load-bearing structure.

[0094] Turning Figure 4b It shows a cut-off view from the rear. Figure 4a An end view of the arrangement. As shown, the rear engine mount structure 15 and its auxiliary components 14, which are configured to support / connect in use, are arranged concentrically around the central axis (previously shown by dashed line 13) of the rear engine mount structure 15, TEC 6, and the engine system 1 itself. This concentric arrangement contributes to a uniform load distribution around the rear engine mount structure 15 and is used to minimize airflow interference, resulting in increased thrust.

[0095] As shown in the figure, an additional component 14 of the heat exchanger may be provided with a cutout area surrounding a connecting rod that connects the rear engine mounting structure 15 to the aircraft structure 2.

[0096] Figure 5a A rear engine mounting structure 15 with multiple (three in this example) mounting points 5 is shown. In this example, the three mounting points 5 are arranged collinearly around the periphery of the extended body 16. Due to the increased number of mounting points 5, the rear engine mounting structure is able to transmit vertical and lateral forces around the engine axis. It should be understood that any arrangement described herein can advantageously have three mounting points.

[0097] In some examples, one of the mounting points 5 (e.g., the middle mounting point among the three mounting points) has an oversized hole (shaped to receive the pin relative to it), and therefore the aforementioned mounting point is only effective in transmitting loads if one or more of the other mounting points / links fail.

[0098] Figure 5b It shows the relationship with Figure 5a The same arrangement is used, except that the connecting rod used to connect mounting point 5 to aircraft structure 2 is meandering. Since the connecting rod overlaps in the axial direction of the rear engine mounting structure 15 / extended body 16, this allows the size of the cut-out area of ​​the additional component 14 (e.g., heat exchanger) to decrease as the area occupied by the connecting rod decreases.

[0099] Figure 6a and Figure 6b Another arrangement of the rear engine mounting structure 15 is shown. As shown, the extended body 16 also includes a surrounding annular portion 17, such as a mounting ring, in which mounting points 5 are provided. The surrounding annular portion 17 circumferentially surrounds and extends around the extended body 16 of the rear engine mounting structure 15, for example, around the central region of the extended body 16. The surrounding annular portion 17 increases the strength of the rear engine mounting structure 15 and advantageously distributes loads. This reduces the load that each component of the arrangement might individually experience, thereby increasing component life. The surrounding annular portion 17 may include a flange to further increase rigidity.

[0100] Furthermore, the use of the annular portion 17 (e.g., a surrounding ring) allows for radial airflow throughout the rear engine mounting structure 15. This is particularly advantageous for additional components such as the heat exchanger 13, which depend on airflow arrangement. It also reduces interference with the airflow leaving the turbine, resulting in increased thrust.

[0101] The surrounding annular portion 17 is connected to the extended body 16 via one or more struts 18. The struts 18 extend radially inward from the surrounding annular portion 17 to the extended body 16. As shown, the surrounding annular portion 17 can have a circular cross-section and can be cylindrical. The struts facilitate the transfer of loads from the annular portion 17 to the extended body 16 and then to the TEC 6. Therefore, the struts help to uniformly distribute the load radially within the rear engine mounting structure 16.

[0102] Advantageously, one or more mounting points 5 may be located in the area where the support column 18 connects to the surrounding annular portion 17 to facilitate load transfer. As previously mentioned, one or more mounting points 5 (particularly one of the three mounting points) may include an oversized hole.

[0103] The additional component 14 can be supported or connected to one or more of the strut 18, the extended body 16, or the surrounding annulus 17 during use. As a result, the weight of the additional component 14 is distributed among the components of the rear engine mounting structure 15.

[0104] In some arrangements (not shown), an inner annular portion circumferentially surrounding the elongated body 16 may be provided between the surrounding annular portion 17 and the elongated body 16. A strut 18 may pass through this inner annular portion. This inner annular portion further increases the strength of the arrangement and provides additional connections for attachments 14 to be connected during use. The struts 18 above and below the inner ring may be non-parallel, in other words, angled relative to each other. This can advantageously guide air throughout the arrangement. One or more struts may be provided with internal channels or cavities for fluid communication, for example, for use with the attachment 14.

[0105] Now will describe Figure 6a and Figure 6b The load path arrangement is as follows. As previously described, the load is transferred between the aircraft structure 2 and the mounting point 5. The load is then transferred to the mounting ring 17 and the strut 18 to the extended body 16, and then along the extended body 16 to the rear side of the TEC 6. Thus, this arrangement advantageously provides multiple load paths from the mounting point 5 to the TEC 6 along different struts 18.

[0106] By providing multiple load paths, the rear engine mounting structure can effectively distribute loads throughout the structure, thereby reducing the load experienced by each individual component. This increases the overall lifespan of the mounting structure and allows for a reduction in the weight of each individual component, as each component is required to bear a reduced amount of load.

[0107] As shown, the surrounding annular portion 17 extends only a portion of the axial range of the elongated body 16. In other examples, the surrounding annular portion 17 may be a surrounding cylinder that extends along the entire radial range of the elongated body 16.

[0108] Although the circumferential spacing of the supports 18 is shown as substantially uniform in this figure, in some cases it may be advantageous to change this spacing. For example, to reduce weight, the upper half surrounding the annular portion 17 may have a greater number of supports 18 than the lower half.

[0109] The elongated body 16 in this arrangement can be tapered, tapered, or flared. This helps to facilitate radial movement of airflow throughout the structure and turbine exhaust. Furthermore, the elongated body 16 can have perforations on its surface to further allow airflow throughout the structure and reduce weight. In some arrangements, the elongated body 16 can be substantially cylindrical.

[0110] Figure 6c It shows the relationship with Figure 6a and Figure 6bA similar arrangement, but with an additional inner annular portion 17b. This inner annular portion 17b provides an additional ring located between the elongated body 16 and the surrounding annular portion 17. As shown, a support 18a connects the elongated body 16 to the inner annular portion 17b, and a support 18b connects the inner annular portion 17b to the surrounding annular portion 17. These supports 18a, 18b can advantageously be non-parallel or angled relative to each other to reduce thermomechanical stress in the component. The addition of the inner annular portion 17b provides additional locations for attaching auxiliary or additional equipment or components.

[0111] Turning Figure 7 It shows the same as Figure 6a and Figure 6b A similar arrangement is adopted, in which multiple axially or longitudinally extending beams 19 are added. These beams are radially spaced around the mounting ring 17 / enclosing annulus 17, and these beams 19 extend forward and rearward from the mounting ring 17, providing increased bending stiffness to the rearward engine mounting structure 15. Furthermore, these beams 19 help to isolate the load from the attachment member 14 during use. As shown, the beams 19 extend the entire axial length of the rearward engine mounting structure 15. This is used to further increase the bending stiffness. The beams 19 may be provided with multiple connection points configured to connect to the attachment member 14 during use.

[0112] For all the arrangements described, the mounting ring 17 (or the surrounding annular portion) may be provided with one or more perforations or cutouts to reduce weight.

[0113] The rear engine mounting structure 15 of this figure also includes a rear plate at the end opposite to the first end, with an elongated body 16 at the first end arranged to connect with the TEC 6 in use. Also as shown, the first ends of a plurality of beams 19 are arranged to connect in use to the outer periphery or ring of the TEC 6, while the elongated body 16 is arranged to connect in use to the inner ring of the TEC 6. Therefore, this arrangement advantageously provides multiple load paths from the mounting point 5 to the TEC 6.

[0114] By providing multiple load paths, the rear engine mounting structure can effectively distribute loads throughout the structure, thereby reducing the load experienced by each individual component. This increases the overall lifespan of the mounting structure and allows for a reduction in the weight of each individual component, as each component is required to bear a reduced amount of load.

[0115] Other arrangements described in this article, such as Figure 7As shown, strut 19 is omitted. When the rear engine mounting structure 15 includes one or more axially extending beams (such as beam 19), the structure can have sufficient rigidity to distribute the strut 19 to save weight. In this arrangement, the axially extending beam connects a portion of the elongated body 16 at its first end to a portion of the elongated body 16 at its second end opposite to its first end. These portions at the first and second ends can be radially extending portions, such as discs extending radially from the elongated body 16 at the first and second ends, connected by the axially extending beams.

[0116] Figure 8a and Figure 8b Another arrangement of the rear engine mounting structure 15 is shown.

[0117] In this arrangement, the elongated body 16 includes multiple beams forming a grid structure, such as a cylindrical or polygonal elongated grid structure. The beams provide strength to the structure and help distribute the load of the additional component 14 throughout the structure. The grid structure also ensures that air can flow radially outward from the turbine exhaust and thus serves to minimize airflow interference, resulting in increased thrust.

[0118] Multiple beams may include axial and transverse beams, or longitudinal beams and diagonal braces, which may be straight or curved, to increase the internal space of the additional component 14. Four or more longitudinal / axial beams (e.g., six as shown in the figure) may be used. The hexagonal cross-section grid structure provides substantial internal space while providing structural stiffness.

[0119] In this arrangement, one or more mounting points 5 (e.g., three) are located at the vertices of the polygonal elongated grid structure. The mounting points 5 transfer the load to the elongated grid structure of the elongated body 16. Furthermore, the elongated body 16 is configured to connect in use to the rear side of the TEC6, such as an outer flange, like the outer periphery of the TEC6 or the engine outlet flange, as described above.

[0120] Therefore, compared to some previous arrangements, the load path of the rear engine mounting structure 15 is connected to the exterior of the TEC 6, rather than the inner flange or interior of the TEC 6. In this arrangement, the cone (if present) does not form part of the structure and is not used to bear part of the load of the additional component 14. This may be advantageous for certain arrangements where the cone is absent or where the cone cannot be modified, without adversely affecting engine performance.

[0121] As shown in the figure, the rear engine mounting structure 15 may include a support ring 8 located at an end opposite to the end that is connected to the rear side of the TEC 6 in use. This support ring 8 can further provide rigidity to the arrangement.

[0122] Figure 9 It shows the relationship with Figure 8a and Figure 8b A similar arrangement. Figure 9 The arrangement further includes a mounting ring 20 that circumferentially surrounds the elongated body 16 and provides mounting points 5. In other words, mounting points 5 are located on the mounting ring 20. The mounting ring 20 increases the strength and rigidity of the rear engine mounting structure 15. The mounting ring 20 also serves to uniformly transfer loads circumferentially throughout the entire rear engine mounting structure 16.

[0123] Figure 10a and Figure 10b It shows the relationship with Figure 8a , Figure 8b and Figure 9 A similar arrangement. The arrangement of Figure 10 additionally or alternatively includes a plate 22 positioned at a second end opposite to the first end (i.e., at the rear end of the rear engine mounting structure 15). A center structure 21 is attached to the plate 22. The center structure 21 may be tapered, tapered, or flared. The plate 22 and the center structure 21 together form a second load path from the mounting point 5 to the interior of the TEC 6 (e.g., the inner flange or the engine outlet inner flange).

[0124] By providing a tapered or tapered center structure 21, interference with the airflow leaving the turbine is minimized. The flared center structure 21 also helps to guide the airflow radially.

[0125] By providing a second load path, the rear engine mounting structure can effectively distribute loads throughout the structure, thereby reducing the load experienced by each individual component. This increases the overall lifespan of the mounting structure and makes it possible to reduce the weight of each individual component, as each component is required to bear a reduced amount of load.

[0126] Figure 11a and Figure 11b Another arrangement of the rear engine mounting structure 15 is shown.

[0127] As shown in the figure, the elongated body 16 in this arrangement is substantially cylindrical. As further shown, the elongated body 16 has perforations on its surface. These perforations can take the form of multiple holes, such as circular, triangular, rectangular, or hexagonal holes. Preferably, the perforations are in the form of multiple triangular holes with rounded corners, as these are efficiently created using a milling machine. By providing perforations on the elongated body 16, the overall weight of the rear engine mount structure 16 is reduced, and air can flow between the internal volume of the rear engine mount structure 16 and its external vicinity. This helps minimize airflow interference with the rear engine mount structure 16 and allows turbine exhaust to pass through it. This increases thrust. The perforations can be made by milling sheet metal.

[0128] Alternatively, the elongated body 16 includes an equal grid arrangement. This arrangement can increase the strength of the elongated body while reducing its weight.

[0129] As shown in the figure, the cross-section of the elongated body is circular. It should be understood that this can alternatively be polygonal, with the perforated pieces joining longitudinal / axial beams (such as...) at the vertices of the polygon. Figure 8a , Figure 8b , Figure 9 , Figure 10a and Figure 10b (As shown).

[0130] Figure 12a and Figure 12b It shows the relationship with Figure 11a and Figure 11b A similar arrangement.

[0131] Figure 12a and Figure 12b The arrangement also includes a mounting ring 20 that substantially circumferentially surrounds the elongated body 16. The mounting ring 20 provides mounting points 5 and increases the strength and rigidity of the rear engine mounting structure 16. The elongated body 16 may be provided with a plurality of circumferentially spaced rings in the axial direction to further increase the strength of the structure.

[0132] For all the arrangements described herein, the mounting ring 20 may be provided with one or more perforations or cutouts to reduce its weight.

[0133] As shown in the figure, air can flow through the perforations in section AA. It should be understood that any arrangement described herein may be provided with perforations, such as perforations on the surface of the elongated body 16. This reduces the weight of the arrangement and allows turbine exhaust to flow past the rear engine mounting structure 16, thereby minimizing its impact on the airflow path.

[0134] The components of the rear engine mounting structure 16 described herein can be formed of a nickel alloy. Alternatively, the components can be formed of alloy steel (ferritic or austenitic).

[0135] The arrangement described herein can be manufactured using any suitable technique such as forging, pressing, sheet forming, chemical milling, casting, conventional machining, or hydroforming. These techniques allow for the formation of aerodynamic shapes to define the desired geometry defined by a particular engine. Components of the described arrangement can be joined using various techniques such as welding, brazing, and mechanical joints such as bolts, rivets, and pins.

[0136] Additive manufacturing technology can also be conveniently used to form components of the rear engine mounting structure 16 or the rear engine mounting structure 16 itself. Additive manufacturing technology involves, for example, using powder bed technology such as laser beam melting to construct three-dimensional shapes as a series or layers. Complex geometries can be conveniently formed with minimal material waste.

[0137] Additive manufacturing techniques that can be used to form all or part of the invention described herein include, but are not limited to: Powder bed fusion method; Direct laser sintering of metals (DMLS); Electron beam melting (EBM); Selective laser melting (SLM); Selective laser sintering (SLS); Direct metal wire deposition; and Direct metal powder deposition.

Claims

1. A rear engine mounting structure for connecting an engine system to an aircraft structure, the rear engine mounting structure comprising: An elongated body having a first end arranged for connection to the rear side of a turbine exhaust casing in use, the elongated body including one or more mounting points for connection to the aircraft structure, wherein the one or more mounting points are spaced apart from the first end in the axial direction.

2. The rear engine mounting structure according to claim 1, wherein, The first end is arranged to be connected to the inner ring portion of the turbine exhaust housing during use.

3. The rear engine mounting structure according to claim 1, wherein, The first end is arranged to be connected to the outer ring of the turbine exhaust casing during use.

4. The rear engine mounting structure according to any of the preceding claims, wherein, The elongated body also includes a surrounding annular portion that provides the one or more mounting points, the surrounding annular portion including one or more radially inwardly extending struts that connect the surrounding annular portion to a portion of the elongated body.

5. The rear engine mounting structure according to claim 4, wherein, The elongated body further includes an inner annular portion disposed between the elongated body and the surrounding annular portion, wherein the support connects the surrounding annular portion to the portion of the elongated body via the inner annular portion.

6. The rear engine mounting structure according to claim 5, wherein, The upper part of the support connecting the surrounding annular portion to the inner annular portion and the lower part of the support connecting the inner annular portion to the portion of the elongated body are not parallel.

7. The rear engine mounting structure according to any one of claims 4 to 6, wherein, The circumferential spacing between different pairs of pillars is different.

8. The rear engine mounting structure according to any one of claims 4 to 7, further comprising one or more radially spaced and axially extending beams.

9. The rear engine mounting structure according to any one of claims 4 to 8, wherein, One or more pillars include internal channels for communicating fluid, and / or, optionally, the surrounding annular portion includes one or more perforations.

10. The rear engine mounting structure according to any one of claims 1 to 3, wherein, The elongated body also includes a surrounding annular portion that provides the one or more mounting points and is connected to one or more axially extending beams that connect a portion of the elongated body at its first end to a portion of the elongated body at its second end opposite to the first end.

11. The rear engine mounting structure according to claim 10, wherein, The portion of the elongated body at its first and second ends is a radially extending portion, and / or the surrounding annular portion includes one or more perforations.

12. The rear engine mounting structure according to claim 1 or 2, wherein, The one or more mounting points are provided on the surface of the elongated body.

13. The rear engine mounting structure according to any of the preceding claims, wherein, The elongated body is tapered, conical, or trumpet-shaped.

14. The rear engine mounting structure according to claim 1 or 3, wherein, The elongated body includes multiple beams forming a grid structure, wherein, optionally, the multiple beams include axial beams and transverse beams.

15. The rear engine mounting structure according to claim 1, 3, or 14, wherein, The elongated body includes a plate and a central structure, wherein the plate is positioned at a second end opposite to the first end, and the central structure is attached to the plate and arranged to connect to the inner flange of the turbine exhaust housing in use.

16. The rear engine mounting structure according to claims 14 to 15, wherein, The elongated body has a polygonal or annular cross-section.

17. The rear engine mounting structure according to claims 14 to 16, wherein, The mounting point is located on the mounting ring, which circumferentially surrounds the elongated body.

18. The rear engine mounting structure according to claim 17, wherein, The mounting ring is circular or polygonal.

19. The rear engine mounting structure according to claim 18, wherein, The mounting ring is polygonal, and the mounting point is located at the vertex of the polygonal mounting ring.

20. The rear engine mounting structure according to claims 14 to 19, wherein, The elongated body includes a rear ring at a second end opposite to the first end.

21. The rear engine mounting structure according to claim 1 or 3, wherein, The elongated body is approximately cylindrical.

22. The rear engine mounting structure according to claim 21, wherein, The elongated body has perforations on its surface.

23. The rear engine mounting structure according to claim 21, wherein, The elongated body includes an equal grid arrangement structure.

24. The rear engine mounting structure according to claims 21 to 23, wherein, The mounting point is located on the surface of the elongated body or on the mounting ring, the mounting ring circumferentially surrounding the elongated body.

25. The rear engine mounting structure according to any of the preceding claims, wherein, There are three installation points.

26. The rear engine mounting structure according to any of the preceding claims, wherein, One of the mounting points includes an oversized hole.

27. The rear engine mounting structure according to any one of claims 17 to 20 and 24, wherein, The mounting ring provides one or more perforations.

28. A rear engine mounting structure for connecting an engine system to an aircraft structure, the rear engine mounting structure comprising: An annular body, the annular body including one or more mounting points for connection to the aircraft structure; as well as One or more radially inwardly extending struts connect the annular body to an elongated central body, the first end of which is arranged for connection in use to the rear side of the turbine exhaust casing of the engine system.

29. A method for connecting an engine system to an aircraft structure, the method comprising: Provide a rear engine mounting structure according to any one of claims 1 to 28; Connect the first end to the rear side of the turbine exhaust casing of the engine system; as well as Connect the one or more mounting points to the aircraft structure.

30. An aircraft comprising a rear engine mounting structure according to any one of claims 1 to 28.

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