Suspension of a turbomachine component to the turbomachine structure

Abstract

Suspension (10) of a component (7) of a turbomachine (1) to a structure (1a) of the turbomachine, comprising at least one connecting rod (11) articulated by a first end (12) on a journal (13) and by a second end (14) on a fitting (15) integral with the structure (1a) of the turbomachine (1), the journal (13) being connected to the component (7) by means of a flexible link (20), the flexible link (20) comprising two coaxial laminated cylinders (21, 22) supporting the journal (13) and each comprising an alternation of at least one layer of elastomeric material (21c 22c) and at least one intermediate layer of thermally conductive and elastically deformable metallic material (21d, 22d). The suspension (10) further includes a thermal limiting device (30) configured to limit the temperature of the intermediate layers of metallic material (21d, 22d). Figure for the abstract: [Fig 3]

Description

Title of the invention: Suspension of a turbomachine component to the turbomachine structure Technical field of the invention

[0001] The present invention relates to the field of power transmission.

[0002] More particularly, the present invention relates to suspensions, in particular of a component of a turbomachine to the structure of the turbomachine, and more particularly targets damping bearings configured to attenuate vibrations between the suspended component and the supporting structure. Prior art

[0003] Gas turbine aircraft engines are generally equipped with an accessory relay box mounted on their external casing.

[0004] The invention finds a privileged application in gearboxes configured to drive accessories (fuel pump, recovery pump, hydraulic pump, etc.), or "accessory gearbox", acronym "AGB", in Anglo-Saxon terms located in the inter-vein compartment of the engine, separating the primary and secondary veins of a twin-flow turbomachine.

[0005] Indeed, temperatures in this compartment are generally higher than those encountered in the ventilation zone, i.e., outside the secondary, cold-flow channel. The suspensions of an AGB in the inter-channel zone include connecting rods linking the AGB to a generally hot engine casing, for example, the high-pressure compressor casing.

[0006] As stresses are applied to these shock-absorbing bearings, they tend to collapse, detach from their housing, or even fail to return to their initial position.

[0007] French document FR 2 917 711 - Al describes a turbomachine suspension comprising a flexible link formed by two laminated cylinders comprising alternating layers of elastomeric material and rigid metallic layers. This flexible link supports a trunnion and dampens vibrations between the engine and the casing.

[0008] The major drawback of this solution is the potential for the metallic layers to overheat when the flexible connection is subjected to stress. Furthermore, if the suspension is located in an area with relatively high temperatures, the heat generated during stress on the flexible connection is not sufficiently dissipated by the ambient air, and the temperature of the elastomeric material layers may rise to the point of damaging them.

[0009] In order to remedy the problem of protecting a shock-absorbing bearing from high temperatures which can damage the layers of elastomer material, it is known to place the bearing in a cold area, in particular away from the hot parts of the engine.

[0010] However, for certain turbomachine components intended to be suspended in areas subjected to relatively high temperatures, such a solution is not feasible. Description of the invention

[0011] The present invention therefore aims to overcome the aforementioned drawbacks.

[0012] The aim of the invention is therefore to improve known shock-absorbing bearings, in particular those used in accessory gearboxes configured to drive accessories (fuel pump, recovery pump, hydraulic pump, etc.), or "accessory gearbox", acronym "AGB", in Anglo-Saxon terms located in the inter-vein compartment of the engine, separating the primary and secondary veins of a twin-flow turbomachine.

[0013] The invention aims to limit the temperature increase within a shock-absorbing bearing.

[0014] The invention relates to a suspension of a component of a turbomachine to a structure of the turbomachine. The suspension comprises at least one connecting rod articulated at one end on a trunnion and at the other end on a fitting fixed to the structure of the turbomachine.

[0015] The trunnion is connected to the organ by means of a flexible link.

[0016] The flexible link comprises two coaxial laminated cylinders supporting the trunnion and each comprising an alternation of at least one layer of elastomeric material and at least one intermediate layer or lamella of thermally conductive and elastically deformable metallic material.

[0017] The suspension further includes a thermal limiting device configured to limit the temperature of the intermediate layers of metallic material, particularly during stresses on the flexible connection.

[0018] For example, the turbomachine component is an accessory box.

[0019] Generally speaking, the turbomachine component can be any equipment suspended in a hot area of ​​the turbomachine.

[0020] The flexible link has the function of damping the vibrations between the source constituted by the engine and the structure of the turbomachine.

[0021] The flexible link connects the journal to the connecting rod.

[0022] The flexible connection can also be called a "shock absorber bearing".

[0023] The cylinders are mounted respectively in housings provided on the structure of the turbomachine.

[0024] The intermediate layer(s) of metallic material may be in the form of strips.

[0025] In general, the intermediate layer or layers of metallic material are elastically deformable, that is to say, they are capable of deforming elastically under the action of an external stress and of returning to their initial position when the external stress is stopped.

[0026] Each intermediate metallic layer may have an annular, flat, rectangular, discoidal or any other shape.

[0027] Advantageously, the thermal limiting device includes at least one thermally conductive device associated with each cylinder and connecting at least one metallic intermediate layer to a thermally conductive zone configured to absorb heat from the thermally conductive device.

[0028] This thermally conductive zone is preferably located as close as possible to the suspension in order to ensure minimal bulk and thus good integration of the thermal limiting device. For example, the thermally conductive zone can be located on one of the housings of the accessory relay box.

[0029] Preferably, the thermally conductive device is connected to the associated metallic intermediate layer by a conductive connecting element, for example a metallic lug.

[0030] For example, the conductive connecting element is connected to the associated metallic intermediate layer by brazing, welding or any other process allowing good thermal conduction.

[0031] For example, the thermally conductive device is flexible, for example in the form of a flexible cable or braid, or articulated, for example in the form of a spherical connecting rod.

[0032] According to one embodiment, each of the cylinders comprises a first rigid, metallic, annular reinforcement, integral with the trunnion, a second rigid, annular reinforcement coaxial with the first reinforcement, and between the two, at least two layers of elastomeric material, alternating with at least one intermediate metallic layer.

[0033] Preferably, all the layers adhere to each other.

[0034] According to one embodiment, each of the intermediate layers of metallic material of each cylinder is connected by at least one thermally conductive device to the thermally conductive zone.

[0035] It could also be envisaged that a thermally conductive device connects several intermediate metallic layers of each cylinder to the thermally conductive zone.

[0036] For example, the fitting attached to the turbomachine comprises a shaft, a ball joint inserted into an opening in the second end of the connecting rod, a spacer, and a nut. The connection between the connecting rod and the turbomachine is not radially damped.

[0037] According to a second aspect, the invention relates to an accessory relay box for a turbomachine connected to the turbomachine by a suspension as described above.

[0038] According to another aspect, the invention relates to a turbomachine comprising a motor shaft and an accessory relay box as described above mounted in an area of ​​the intermediate housing of the turbomachine and coupled via a drive shaft, directly or indirectly, to the motor shaft. Brief description of the drawings

[0039] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the indexed drawings in which:

[0040] [Fig.1] schematically illustrates a half axial section of a structure of an example of a turbomachine locating the location of an accessory gearbox configured to drive the accessories (fuel pump, recovery pump, hydraulic pump, etc...), or "accessory gearbox", acronym "AGB", in Anglo-Saxon terms located in the inter-flow compartment of the engine, separating the primary and secondary flow of a twin-flow turbomachine;

[0041] [Fig.2] is an exploded perspective view of a suspension of the accessory relay box of the [Fig.1];

[0042] [Fig.3] is a detailed cross-sectional view of part of the suspension of [Fig.2], illustrating a flexible connection according to one embodiment of the invention;

[0043] [Fig.4A], [Fig.4B] illustrate two distinct embodiments of a flexible connection according to [Fig. 3]; and

[0044] [Fig.5] is an example of a thermally conductive device according to figures 4A and 4B.

[0045] Detailed description of at least one embodiment

[0046] In the following description, the terms "axial" and "radial" are defined with respect to an axis of rotation XI-XI of a rotor of a turbomachine engine 1.

[0047] Figure 1 schematically represents a half-axial section of a turbomachine 1, with a general longitudinal axis XI-XI, for example of the twin-spool, twin-flow turbojet type comprising a fan 2 coupled to an engine a gas turbine comprising a compressor device 3, an annular combustion chamber 4, a high-pressure turbine 5 and a low-pressure turbine 6 intended to supply the compressor device 3.

[0048] For example, the rotors of the high-pressure compressor and the high-pressure turbine are connected by a high-pressure (HP) shaft (not shown) and together form a high-pressure housing. The rotors of the low-pressure compressor and the low-pressure turbine are connected by a low-pressure (LP) shaft (not shown) and together form a low-pressure housing. The HP and LP shafts extend along a longitudinal axis XI-XI of the turbomachine 1.

[0049] The blower shaft 2a is rotationally linked to the BP shaft directly or indirectly.

[0050] Downstream of the blower 2, the main airflow F is separated into a primary airflow Fl and into a secondary airflow F2.

[0051] The primary airflow Fl travels through an internal passage or primary vein VI.

[0052] The secondary airflow F2 travels through an external annular passage or secondary vein VE.

[0053] The turbomachine 1 includes an accessory relay box 7 mounted in an area of ​​the intermediate casing 8 of the turbomachine 1 and coupled via a drive shaft 9, directly or indirectly, to the shaft of the motor 2a.

[0054] It should be noted that the invention is not limited to such a turbomachine structure and could be applied to a turbomachine of a different structure, for example to a turbomachine of the turbofan type with a double-flow turbojet, in which the low-pressure compressor acts as a blower.

[0055] In general, the invention relates to any engine comprising at least one accessory gearbox configured to drive accessories (fuel pump, recovery pump, hydraulic pump, etc.), or "accessory gearbox", acronym "AGB", in Anglo-Saxon terms, located in the inter-vein compartment of the engine.

[0056] It should also be noted that the invention is not limited to the arrangement and structure of the accessory relay housing 7 as seen in [Fig. 1]. An alternative arrangement could indeed be provided in the turbomachine 1.

[0057] Fig.2 illustrates, in exploded perspective, a suspension 10 of the accessory relay box 7 of Fig.1.

[0058] The suspension 10 includes a connecting rod 11 articulated by a first end 12 on a trunnion 13, visible on the [Fig.3], and by a second end 14 on a fitting 15 integral with a structure la of the turbomachine 1.

[0059] The trunnion 13 is connected to the accessory relay box 7 via a flexible link 20.

[0060] As illustrated, and in no way limiting, the fitting 15 integral with the structure la of the turbomachine 1 comprises here a shaft 15a, a ball joint 15b inserted in the orifice 14a of the second end 14, a spacer 15c and a nut 15d. The connection between the connecting rod 11 and the structure la of the turbomachine 1 is not radially damped here.

[0061] The flexible link 20 has the function of damping the vibrations between the source constituted by the motor 1 and the accessory relay box 7.

[0062] The flexible link 20 connects the journal 13 to the connecting rod IL

[0063] The flexible link 20 can also be called a "shock-absorbing bearing".

[0064] The flexible link 20 comprises two coaxial laminated cylinders 21, 22 and comprising each of the layers of elastomeric material alternating with rigid layers of metallic material.

[0065] The cylinders 21, 22 are symmetrical with respect to the plane perpendicular to the journal 13 passing through the connecting rod 11.

[0066] The cylinders 21, 22 are mounted respectively in housings 1b, provided on the component 7, for example in a clevis attached to a housing 7a of the component 7.

[0067] Each of the cylinders 21, 22 comprises a first rigid, metallic, annular armature 21a, 22a, integral with the trunnion 13, a second rigid, annular armature 21b, 22b, coaxial with the first armature 21a, 22a, and between the two, layers of elastomeric material 21c, 22c, here three in number, alternating with one or more intermediate layers of metallic material 21d, 22d, here two in number.

[0068] All the layers adhere to each other.

[0069] The intermediate layers of metallic material 21d, 22d can be in the form of lamellae.

[0070] In general, the intermediate layers of metallic material 21d, 22d are elastically deformable, that is to say, they are capable of deforming elastically under the action of an external stress and of returning to their initial position when the external stress is stopped.

[0071] The intermediate layers of metallic material 21d, 22d are made of a metallic material configured to ensure good thermal conductivity.

[0072] The intermediate layers of metallic material 21d, 22d may have an annular, flat, rectangular, discoidal or any other shape in cross-section.

[0073] The trunnion 13 is supported by the two cylinders 21, 22 and a ball joint 16a inserted in the orifice 12a of the first end 12 and is made solid by means of a washer 16b and a nut 16c screwed to the threaded end 13a of the trunnion 13 and held axially by a pin 16d cooperating with a bore 13b provided at the end of the trunnion 13.

[0074] The suspension 10 further includes a thermal limiting device 30 configured to limit the temperature of the layers or lamellae of metallic material 21d, 22d during stresses on the flexible link 20.

[0075] The thermal limiting device 30 includes a thermally conductive device 32 connecting a metallic intermediate layer 21d, 22d to a thermally conductive zone 34 configured to absorb heat from the thermally conductive device 32.

[0076] This thermally conductive zone 34 is preferably located as close as possible to the suspension in order to ensure minimal bulk and thus good integration of the thermal limiting device 30. For example, the thermally conductive zone 34 can be located at the level of a housing 7a of the accessory relay box 7.

[0077] The thermally conductive device 32 is connected to the metallic intermediate layer 21d, 22d by a conductive connecting element 36, for example a metallic lug.

[0078] The conductive connecting element 36 is connected to the metallic intermediate layer 21d, 22d by brazing, welding or any other process allowing good thermal conduction.

[0079] As illustrated, and in no way limiting, each of the two intermediate layers of metallic material 21d, 22d of each cylinder 21, 22 is connected each by a thermally conductive device 32 to the thermally conductive zone 34.

[0080] Generally, at least one intermediate metallic layer 21d, 22d of each cylinder 21, 22 is connected by a thermally conductive device 32 to the thermally conductive zone 34.

[0081] It could be envisaged that a thermally conductive device 32 connects several intermediate metallic layers 21d, 22d of each cylinder 21, 22 to the thermally conductive zone 34.

[0082] As illustrated in Figures 4A, 4B, and 5, the thermally conductive device 32 is in the form of a flexible braid.

[0083] Alternatively, the thermally conductive device 32 could be in the form of a joint. However, a jointed connection would require spherical connecting rods with good heat conduction at the joints, which could be more expensive.

[0084] Thus, a flexible connection was preferred, such as a cable or a metal braid.

[0085] The invention consists of placing a heat-conducting device on a shock-absorbing bearing or a flexible connection whose damping part comprises a plurality of layers composed of alternating strips of metallic material and layers of elastomer material.

[0086] The metallic material strips structure the bearing and allow the bearing to return to its initial position throughout its life.

[0087] The solution makes it possible to achieve a flexible connection between the journal and the turbomachine structure through which the forces exerted by the connecting rod on the journal travel, while limiting the temperature rise of the damping bearing and preserving the integrity of the elastomer material layers.

Claims

Demands

1. Suspension (10) of a component (7) of a turbomachine (1) to a structure (la) of the turbomachine, comprising at least one connecting rod (11) articulated at a first end (12) to a journal (13) and at a second end (14) to a fitting (15) integral with the structure (la) of the turbomachine (1), the journal (13) being connected to the component (7) by means of a flexible linkage (20), the flexible linkage (20) comprising two coaxial laminated cylinders (21, 22) supporting the journal (13) and each comprising an alternation of at least one layer of elastomeric material (21c, 22c) and at least one intermediate layer of thermally conductive and elastically deformable metallic material (21d, 22d), characterized in that the suspension (10) further comprises a thermal limiting device (30) configured to limit the temperature of the intermediate layers in metallic material (21d, 22d).

2. Suspension (10) according to claim 1, wherein the thermal limiting device (30) comprises at least one thermally conductive device (32) associated with each cylinder (21, 22) and connecting at least one intermediate layer of metallic material (21d, 22d) to a thermally conductive zone (34) configured to absorb heat from the thermally conductive device (32).

3. Suspension (10) according to claim 2, wherein the thermally conductive device (32) is connected to the associated intermediate layer of metallic material (21d, 22d) by a conductive connecting element (36).

4. Suspension (10) according to claim 3, wherein the conductive connecting element (36) is connected to the associated intermediate layer of metallic material (21d, 22d) by brazing, welding or any other process allowing good thermal conduction.

5. Suspension (10) according to any one of claims 2 to 4, wherein the thermally conductive device (32) is flexible or articulated.

6. Suspension (10) according to any one of the preceding claims, wherein each of the cylinders (21, 22) comprises a first rigid, metallic, annular frame (21a, 22a), integral with the trunnion (13), a second rigid, annular frame (21b, 22b) coaxial to the first armature (21a, 22a), and between the two, at least two layers of elastomeric material (21c, 22c), alternating with at least one intermediate layer of metallic material (21d, 22d).

7. Suspension (10) according to claim 6 taken in combination with any one of claims 2 to 5, wherein each of the intermediate layers of metallic material (21d, 22d) of each cylinder (21, 22) is connected each by at least one thermally conductive device (32) to the thermally conductive zone (34).

8. Suspension (10) according to any one of the preceding claims, wherein the fitting (15) integral with the turbomachine (1) comprises a shaft (15a), a ball joint (15b) inserted into an orifice (14a) of the second end (14) of the connecting rod (11), a spacer (15c) and a nut (15d).

9. Accessory relay box (7) for turbomachine, connected to the turbomachine by a suspension (10) according to any one of the preceding claims.

10. Turbomachine (1) comprising a main shaft (2a) and an accessory relay box (7) according to claim 9, said accessory relay box (7) being mounted in an inter-vein compartment area (8) of the turbomachine (1) and coupled via at least one drive shaft (9) to the main shaft (2a).

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