ANNULAR COMPONENT FOR SUPPORTING A TURBINE ENGINE BEARING

Abstract

A component (1, 2) for supporting at least one bearing (3) for a turbine engine (10) comprising: two coaxial walls, internal (4) and external (5) walls respectively, defining a gas flow vein (6) between them and interconnected by a row of arms (7); an external ferrule (50) comprising an internal peripheral edge (51) connected to the external wall (5) and an external peripheral edge (52) connected to an external mounting flange (53); an internal ferrule (40) comprising an external peripheral edge (41) connected to the internal wall (4) and an internal peripheral edge (42) comprising an internal mounting flange (43); at least one of the ferrules (4, 5), which at the peripheral edge (41, 51) thereof is connected to the corresponding wall (4, 5), having a general shape which is corrugated about an axis (X-X) of the component (1, 2).

Claims

1. An annular component of supporting at least one bearing, for a turbine engine, in particular for an aircraft, comprising: two coaxial annular walls, internal and external respectively, these walls delimiting between them an annular gas flow vein and being connected together by an annular row of arms; an external annular shell extending around the external annular wall, this shell comprising an internal peripheral edge connected to the external annular wall and an external peripheral edge connected to an annular fixing flange, referred to as “external flange”; an internal annular shell extending inside the internal annular wall, this shell comprising an external peripheral edge connected to the internal annular wall and an internal peripheral edge comprising an annular fixing flange, referred to as the “internal flange”; the annular component wherein at least one of the shells has its external or internal peripheral edge which is connected to the corresponding annular wall and which has a generally corrugated shape around an axis of the annular component.

2. The annular component according to claim 1, wherein only one of the shells has its external or internal peripheral edge corrugated and connected to the corresponding annular wall.

3. The annular component according to claim 2, wherein the other of the shells has its external or internal peripheral edge connected to the corresponding annular wall, this external or internal peripheral edge has a generally circular shape around the axis of the component, this shell having openings which are through openings and which are aligned substantially circumferentially with the arms.

4. The annular component according to claim 1, wherein the internal and external shells each have their external or internal peripheral edge connected to the corresponding annular wall, which is corrugated.

5. The annular component according to claim 1, wherein the arms are hollow for the passage of auxiliaries.

6. The annular component according claim 1, wherein the annular walls each comprise an annular row of holes which are through holes and which open into the arms.

7. The annular component according to claim 3, wherein the annular walls each comprise an annular row of holes which are through holes and which open into the arms and said circular peripheral edge of the other of the shells extends in a plane perpendicular to the axis and passing through the holes of the annular wall to which said peripheral edge is connected.

8. The annular component according to claim 3, wherein the annular walls each comprise an annular row of holes which are through holes and which open into the arms and said circular peripheral edge of the other of the shells extends in a plane inclined with respect to the axis of the annular component and passing through the holes of the annular wall to which peripheral edge is connected.

9. The annular component according to claim 6, wherein the corrugated peripheral edge comprises hollow portions and hump portions, each hollow portion extending around a hole of the annular wall to which that edge is connected, and each hump portion extending between two adjacent holes of that wall.

10. The annular component according to claim 1, wherein the corrugated peripheral edge forms corrugations of constant amplitude.

11. The annular component according to claim 1, wherein the corrugated peripheral edge forms corrugations of variable amplitude.

12. The annular component according to claim 1, wherein the maximum amplitude of the corrugation is between 10% and 90%.

13. A turbine engine, in particular for an aircraft turbine engine, comprising at least one annular component according to claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0034] The invention will be better understood and other details, features and advantages of the invention will become clearer on reading the following description made by way of non-limiting example and with reference to the attached drawings in which:

[0035] FIG. 1 is a schematic half-view in axial section of a component of a turbine engine in which an annular support component for at least one bearing is arranged, according to a first embodiment of the invention;

[0036] FIG. 2 is a schematic perspective view of the annular component shown in FIG. 1;

[0037] FIG. 3 is a schematic half-view in axial section of the annular component of FIGS. 1 and 2;

[0038] FIG. 4 is a schematic perspective view of an annular support component according to a second embodiment of the invention;

[0039] FIG. 5 is a schematic side view of the annular component of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

[0040] By convention in the present application, the terms “inside” and “outside”, and “internal” and “external” are used in reference to a positioning with respect to an axis X-X of rotation of a turbine engine. For example, a cylinder extending along the axis X-X of the engine comprises an inside surface facing the engine axis and an outside surface opposite its inside surface. “Longitudinal” or “longitudinally” means any direction parallel to the axis X-X, and “transversely” or “transversal” means any direction perpendicular to the axis X-X. Similarly, the terms “upstream” and “downstream” are defined in relation to the direction of airflow in the turbine engine.

[0041] FIG. 1 illustrates component of a turbine engine 10, such as an aircraft turboshaft engine, comprising an annular component 1 for supporting bearings 3 of the invention, which enables to guide a shaft 20 driven by a turbine arranged downstream of this annular component 1. The gases, coming from a gas generator (not shown), pass through a flow vein 6 of this component 1.

[0042] The component 1 is connected, on the one hand, to a set of elements 22, 23 of an external structure of the turbine engine 10, and on the other hand, to an internal structure 21 carrying the bearings 3 of the turbine engine 10. Downstream of this component 1, the gases pass through, for example, a free turbine stator and then a free turbine wheel to which they transmit their energy (not shown). This free turbine wheel is mechanically connected to the shaft 20, which is guided by the bearings 3 and which recovers the power from the turbine engine. These bearings 3 are carried by the internal structure 21 which is connected to the component 1 of the invention.

[0043] FIGS. 1 to 3 illustrate a first embodiment of the component 1 and FIGS. 4 to 5 illustrate a second embodiment of this component 2.

[0044] According to the first embodiment, the component 1 has a shape of revolution extending around an axis which is coincident with the axis X-X of the turbine engine.

[0045] With reference to FIG. 2, the component 1 comprises two annular walls, respectively internal 4 and external 5, which are connected to each other by arms 7. These arms 7 may be solid or tubular (or otherwise said to be hollow) for example for the passage of auxiliaries 8. This component 1 further comprises an internal annular shell 40 extending radially inside the internal annular wall 4 and an external annular shell 50 which extends around the external annular wall 5.

[0046] The internal annular shell 40 comprises an external peripheral edge 41 connected to the internal annular wall 4 and an internal peripheral edge 42 coprising an internal fixing flange 43. This internal flange 43 may be connected by fastening means (such as bolts) to a flange of the internal structure 21 of the turbine engine 10, as shown for example in FIG. 1.

[0047] The external annular shell 50 comprises an internal peripheral edge 51 connected to the external annular wall 5 and an external peripheral edge 52 comprising an external fixing flange 53. This external flange 53 may also be connected by fastening means (such as bolts) to flanges of the external structure 22, 23 of the turbine engine 10, as shown in FIG. 1.

[0048] In the example shown, the external edge 41 connected to the internal wall 4 comprises corrugations 9 arranged around the axis X-X, while the internal edge 51 connected to the external wall 5 has a generally circular shape.

[0049] The external shell 50 comprises openings 12 (or “lunulae” as mentioned above) which are through openings and are substantially radially aligned with the arms 7.

[0050] The walls 4, 5 comprise holes 11 which also are through holes and which open into the arms 7. The arms 7, openings 12 and holes 11 are at least partially aligned substantially radially with each other, for example to allow the passage of auxiliaries 8, as illustrated for example in FIG. 1. Non-limitingly, the holes 11 are dimensioned so as to have a substantially smaller area than the openings 12. The dimensions of the holes 11 and the openings 12 are for example chosen according to the overall size of the component 1 for supporting the bearing, the rotational speed of the shaft 20, the need for the passage of the auxiliary 8, the levels of mechanical loading, in particular for the openings and the type of turbine engine 10.

[0051] With reference to FIG. 3, the elements composing the component 1 are described in detail with respect, on the one hand, to several planes perpendicular P to the axis X-X and parallel to each other, and on the other hand, to several tangent planes T which are oblique to the axis X-X and form angles of inclination α.

[0052] The internal wall 4 and external wall 5 each extend along a tangent plane, respectively plane T4 and plane T5. The internal wall 4 is thus inclined in an oblique direction to the axis X-X forming an angle of inclination α4, and the external wall 5 is inclined in an oblique direction to the axis X-X forming an angle of inclination α5.

[0053] Each arm 7 extends radially between the internal wall 4 and the external wall 5 and may be inclined in an oblique direction with respect to the axis X-X forming an angle of inclination α7. The arm 7 comprises an internal cavity bounded by a wall 7a located upstream to form a leading edge of the arm and passing through a tangent plane T7a, and a wall 7b located downstream to form a trailing edge and passing through a tangent plane T7b parallel to plane T7a.

[0054] The internal shell 40 extends substantially axially and comprises, on the upstream side, the external edge 41 which passes through a plane P41, and, on the downstream side, the internal edge 42 which passes through a plane P42. This internal shell 40 extends substantially radially, on the one hand, towards the outside through the plane P41 of the external edge 41 connecting the internal wall 4, and on the other hand, towards the inside through the plane P42 which comprises the internal flange 43. In axial section, the internal shell 40 connected to the internal wall 4 comprises a curved shape with a concavity directed downstream.

[0055] The external shell 50 extends substantially axially and comprises on the upstream side the internal edge 51 passing through a plane P51, and on the downstream side the external edge 52 passing through a plane P52. This external shell 50 extends substantially radially toward the outside through the plane P52 which comprises the external flange 53. In axial cross-section, the external shell connected to the external wall 5 comprises a half-arc curved shape with a concavity directed downstream. The plane P41 of the internal shell 40 connected to the internal wall 4 is disposed between the planes P51 and P52 of the external shell 50, and the plane P42 of the internal edge 42 of the internal shell 40 is disposed downstream of the plane P52 of the external shell 50.

[0056] In the example shown, the opening 11 has a generally elongate shape extending between an upstream end 11a passing substantially through plane T7a and a downstream end 11b passing substantially through plane T7b, such that this opening in the internal wall 4 opens into the internal cavity of the arm 7. Similarly, the opening 12 also extends upstream to downstream between tangent planes T7a and T7b, such that this opening in the external wall 5 opens into the internal cavity of the arm 7.

[0057] In particular, the plane P41 of the internal shell 40 connected to the internal wall 4 is arranged between the planes T7a and T7b of the arm 7, and closer to the plane T7b of the wall 7b than to the plane T7a of the wall 7a. The external edge 41 of the internal shell 40, which passes through this plane 41, therefore partially closes the internal cavity of the arm 7 and the downstream end 11b of the hole. The plane P51 of the external shell 50 connected to the external wall 5 is almost joined to the plane T7a of the wall 7a of the arm by the internal edge 51.

[0058] The corrugated edge 41 comprises hollow portions 90 and hump portions 91 alternately to form corrugations 9 between the planes P41 and P51. Each hollow portion 90 is disposed around a hole 11, preferably around the downstream end 11b and passing substantially through a plane P11b. The hump portion 91 is arranged between two adjacent holes 11.

[0059] Advantageously, the corrugations 9 comprise an amplitude A1 substantially similar to a total length L1 of the arm 7 measured along the axis X-X (FIG. 1). This amplitude A1 may be constant or variable depending on the size and/or position, respectively similar or different, of the arms 7. In FIGS. 1 and 2, the arms 7, five in number, are substantially of the same size and arranged equidistant from each other, so that the corrugations 9 have a constant amplitude around the axis X-X. The annular component 1 may comprise more or less than five arms depending on the functional requirement of this component in the turbine engine.

[0060] FIGS. 4 and 5 illustrate the second embodiment. The component 2 is distinguished from the component 1 by the external edge 41 connected to the annular wall 4 which has a generally circular shape, whereas the internal edge 51 comprises corrugations 9 arranged around the axis X-X. This corrugated edge 51 extends in a plane P51 downstream of the component 2 and perpendicular to the axis X-X, and the external edge 52 extends in a plane P52 upstream which is parallel to P51. The internal shell 40 comprises openings 12 which are through openings and which are substantially radially aligned with the arms 7. The annular walls 4, 5 comprise holes 11 which are through holes and which open into the arms 7. The arms 7, the openings 12 and the holes 11 are also at least partially radially aligned with each other to allow the passage of auxiliaries 8. The openings 12 are different in shape and size from the holes 11.

[0061] The holes 11 in the external annular wall 5 are elongate in shape similar to an aircraft wing having a leading edge which is the front of the airflow profile and a trailing edge which is the rear of the airflow profile. Thus comparably, the hole 11 comprises an upstream end 11a passing through a plane P11a perpendicular to the axis X-X and forming a leading edge, and a downstream end 11b passing through a plane P11b perpendicular to the axis X-X and forming a trailing edge. The downstream end 11b is smaller and also axially and radially offset from the upstream end 11a of the hole. Thus, the upstream end 11a of the hole is sufficiently large to allow the auxiliary passage 8, while the downstream end 11b of the hole is close to the edge 51 connected to the external wall 5 to allow the formation of the corrugations 9.

[0062] In particular, the corrugations 9 also comprise hollow portions 90 and hump portions 91. Each hollow portion 90 comprises a hollow passing through a plane P90 and located close to the downstream end 11b of the hole, so as to circumvent this hole. Each hump portion 91 comprises an apex passing through a plane P91 and located substantially between two downstream ends 11b of two adjacent holes.

[0063] Advantageously, the corrugations 9 comprise an amplitude A2 of between 15% and 20%, with respect to a total length L2 of the arm 7 measured along the axis X-X. This amplitude A2 of the corrugations 9 may be constant or variable depending on the dimensioning, respectively similar or different, of the arms 7. In FIGS. 4 and 5, the arms 7 are substantially of the same size and arranged equidistant from each other, so that the corrugations 10 have a constant amplitude around the axis X-X of the component. In these two embodiments, the corrugations of the connecting edge of at least one of the shells create a non-axisymmetry to compensate for the quasi-axisymmetric stress field at this shell, while reinforcing the sealing of the component.

[0064] The annular components 1, 2 of the invention can be made by casting or by additive manufacturing. It should be noted that the creation of the corrugations on the annular component does not introduce any major manufacturing problems. For example, the casting process allows the corrugations to be produced without introducing any prohibitive additional cost in series production.

[0065] The annular components for supporting the bearings of the invention provide several advantages compared to the prior art, in particular: [0066] improving the sealing by eliminating the openings at the level of the shells of the annular support component; [0067] reliably and stably maintain the bearings of the turbine engine shafts; [0068] ensure efficient auxiliary passage, e.g. for the bearings of the rotating elements of the internal structure carrying the bearings; [0069] guarantee stress containment in the shells in order to limit crack propagation during the fatigue initiation phase; [0070] guarantee mechanical resistance under thermomechanical stress or vibratory positioning in the conditions of the engine in operation; [0071] easily adaptable to current bearings.

[0072] In general, the annular bearing support component with the corrugations of the connecting edge of at least one of the shells improves the performance of the engine and limits aerodynamic disturbances in the gas flow vein of the turbine engine. The proposed solutions are simple, effective and economical to produce and assemble on a turbine engine, while ensuring optimum mechanical strength and life of the annular component for supporting the bearings.