TURBOMACHINE DISC SHEET, CORRESPONDING TURBOMACHINE DISC.

Abstract

The invention relates to a foil (5) for a disk (2) of axis (X) of a turbomachine (1), intended to be mounted in a cell (25) of the disk (2), radially between the disk (2) and a root of a movable blade (3), said cell (25) opening at the external periphery of the disk (2) and being delimited by a bottom (20) and two side walls (21) extending circumferentially on either side of said bottom (20), the foil (5) comprising: a base (50) intended to extend longitudinally along the axis (X) and configured to be mounted radially opposite said bottom (20) of said cell (25);two lateral branches (51) each configured to be mounted circumferentially opposite one of the two lateral walls (21) of said cell (25), the foil (5) having axial stop means of the click (5) in the cell (25), the axial stop means (52) of the click (5) in the cell (25) extending in circumferential projection from at least one of the lateral branches (51) and being configured to cooperate with complementary axial stop means (22) of the disc (2). Figure 2.;

Description

Title of the invention: FOIL FOR TURBOMACHINE DISC, CORRESPONDING TURBOMACHINE DISC. Field of invention

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

[0002] More particularly, the invention relates to a foil for a turbomachine disk as well as a corresponding turbomachine disk.

[0003] The invention relates to all types of turbomachines and in particular turbojets and turboprops. State of the prior art

[0004] In a turbomachine, a disk, for example a turbine disk, conventionally comprises blades at its outer periphery, these blades having blade roots which are engaged in substantially axial cells at the outer periphery of the disk. The blades are held radially on the disk by the shape of their roots cooperating with the cells of the disk.

[0005] Bladings of this type are for example described in document FR 2 890 684 A1 in the name of the applicant.

[0006] In order to facilitate the mounting of the blades on the rotor disks, it is necessary to provide sufficient clearance to allow easy sliding of the blade roots in the cells. To prevent wear of the blades and the disk and to guarantee the mechanical integrity of these parts, it is known to place foils between the blade roots and the cells of the disks. More precisely, these foils are mounted around the blade roots before being inserted into the cells of the disks. They are held in position on the blade roots by folded tabs, mainly upstream and downstream of the blade root, with reference to the overall direction of gas flow through the turbomachine in operation.

[0007] However, in operation, the foils tend to move axially, which can damage the tabs or even cut them. Once the tabs are cut, the foils can then disengage from the blade roots, partially or even completely. However, in the event of disengagement, numerous consequences can occur: the foil can insert itself into the air stream and damage the blades located downstream of the turbine, increased wear between the blade and the disc and therefore degraded mechanical strength over time.

[0008] Furthermore, the thermal stresses generated by the sequence of expansions and contractions that the blade undergoes also cause expansion and contraction of the foil, which leads to partial and then total degradation of the foil. In addition, if the expansion of the foil is not synchronized with the expansion of the blade root, decoupling can also occur.

[0009] There is therefore a need to provide a solution making it possible to improve the mechanical strength of such foils and to limit the aforementioned risks. Statement of the invention

[0010] The invention aims to remedy at least in part the drawbacks mentioned above relating to the techniques of the prior art.

[0011] To this end, the invention relates to a foil for a turbomachine X-axis disc, intended to be mounted in a cell of the disc, radially between the disc and a foot of a blade, the cell opening at the external periphery of the disc and being delimited by a bottom and two side walls extending circumferentially on either side of said bottom, the foil comprising: - a base intended to extend longitudinally along the X axis and configured to be mounted radially opposite said bottom of said cell; - two lateral branches each configured to be mounted circumferentially opposite one of the two lateral walls of said cell,

[0012] the foil having axial stop means for the click in the cell, the axial stop means for the click in the cell extending circumferentially from at least one of the lateral branches and being configured to cooperate with complementary axial stop means of the disc.

[0013] Thus, the proposed solution aims to resolve at least in part the drawbacks of the prior art.

[0014] In particular, by implementing a foil which is in contact with the disc and no longer with the blade root, the risks of separation by thermal expansion are limited because the thermal stresses at the disc are lower than at the blade. In fact, the blades are directly placed in the air stream while the disc is cooled by purge air, which creates a thermal difference between the disc and the blades.

[0015] Furthermore, the fact that the thermal stresses are lower at the level of the disc makes it possible to ensure that the axial stop means of the click in the cell retain a complementary shape to the complementary axial stop means throughout the life cycle of these components, which makes it possible to gain in reliability.

[0016] According to a particular aspect of at least one embodiment of the invention, said axial stop means of the click in the cell comprise two depressions positioned opposite, each of said lateral branches carrying one of said two depressions.

[0017] As a result, this makes it possible to limit the number of assembly operations, due to the elimination of the tabs compared to the prior art embodiments.

[0018] According to a particular aspect of at least one embodiment of the invention, each of the depressions has a plane of symmetry.

[0019] According to a particular aspect of at least one embodiment of the invention, each of the depressions is formed by stamping or by machining.

[0020] The invention also relates to a turbomachine disk comprising a plurality of cells opening at the external periphery of the disk, at least one of said cells having complementary axial stop means formed on said surface of said cell and capable of cooperating with axial stop means of a click in the cell carried by a foil.

[0021] According to a particular aspect of at least one embodiment of the invention, the complementary axial stop means comprise two depressions formed in a hollow opposite the cell.

[0022] According to a particular aspect of at least one embodiment of the invention, the complementary hollow axial stop means are each formed on a radially external portion of each of the side walls.

[0023] According to a particular aspect of at least one embodiment of the invention, the complementary hollow axial stop means extend in a median plane with respect to an axial length of said cell.

[0024] According to a particular aspect of at least one embodiment of the invention, said complementary axial stop means are formed by stamping or by machining.

[0025] The invention also relates to a turbomachine assembly comprising a turbomachine disk according to one of the aforementioned embodiments, and at least one foil according to one of the aforementioned embodiments, said axial stop means of the click in the cell extending in circumferential projection from at least one of the lateral branches and cooperating with complementary axial stop means of the disk, formed in a hollow opposite the cell.

[0026] According to a particular aspect of at least one embodiment of the invention, the base of the foil extends over an entire axial length of said bottom of said cell.

[0027] The invention also relates to a turbomachine turbine comprising an assembly according to one of the aforementioned embodiments.

[0028] The invention also relates to a turbomachine comprising a turbine according to the aforementioned embodiment. Presentation of figures

[0029] The invention, as well as the various advantages that it presents, will be more easily understood in the light of the following description of an illustrative and non-limiting embodiment thereof, and of the appended drawings among which: [Fig.l] is a schematic sectional view of a turbomachine; [Fig.2] is a schematic perspective view of a foil according to one embodiment of the invention; [Fig.3] is a schematic perspective view of a foil mounted on a disc according to the embodiment of [Fig.2]; [Fig.4] is a partial schematic perspective view of a foil mounted on a disc according to the embodiment of [Fig.2]; [Fig.5] is a schematic top view of a foil mounted on a disc according to the embodiment of [Fig.2]; [Fig.6] is a schematic top view of a disc according to the embodiment of [Fig.2]; [Fig.7] is a schematic front view of a foil mounted on a disc according to the embodiment of [Fig.2], with a blade root mounted in the cell; [Fig.8] is a schematic perspective view of a foil mounted on a disc according to the embodiment of [Fig.2], with a blade root mounted in the cell, and [Fig.9] is a partial schematic perspective view of a disc according to the embodiment of [Fig.2].

[0030] Detailed description of an embodiment of the invention

[0031] It should be noted that the invention applies to any type of turbomachine, and in particular to aircraft turbomachines.

[0032] This turbomachine 1, which extends along an axis X, is for example intended to be mounted on an aircraft (not shown), such as an airplane or a helicopter, for example under the wing of the aircraft, on the wing or even at the rear of the fuselage of the aircraft.

[0033] The turbomachine 1 illustrated in [Fig.l] is a twin-spool, twin-flow, direct-drive turbojet engine. This is not, however, limiting since the turbomachine 1 may not be intended to be mounted on an aircraft, but may be another type of turbojet engine, such as a geared turbojet engine, a turboprop engine, or an auxiliary power unit (also called an “APU” for “Auxiliary Power Unit”).

[0034] Throughout the description, an axial direction corresponds to the direction of the longitudinal axis X and a radial direction is a direction perpendicular to the longitudinal axis X and intersecting the longitudinal axis X. Similarly, an axial plane is a plane containing the longitudinal axis X and a radial plane is a plane perpendicular to the longitudinal axis X.

[0035] Similarly, the adjectives "inner" (or "internal") and outer ("or external") are used with reference to a radial direction so that the inner part of an element is, in a radial direction, closer to the longitudinal axis X than the outer part of the same element.

[0036] Furthermore, unless otherwise specified, the terms "upstream" and "downstream" are used with reference to the overall direction of gas flow through the turbomachine in operation.

[0037] As visible in [Fig.l], the turbomachine 1 comprises, from upstream to downstream, a fan 10, a compressor section 12, a combustion chamber 14 and a turbine section 16. The longitudinal axis X forms the axis of rotation of at least a part of the compressor section 12 and of the turbine section 16, which are capable of being driven in rotation around the longitudinal axis X relative to a casing 18 of the turbomachine 1.

[0038] In operation, the fan 10 sucks in an air flow, a portion of which, circulating within a primary vein 100, is successively compressed within the compressor section 12, ignited within the combustion chamber 14, and expanded within the turbine section 16 before being ejected from the turbomachine 1. In this way, the turbomachine 1 generates thrust. This thrust can also, for example, be used for the benefit of the aircraft on which the turbomachine 1 is attached and fixed.

[0039] Several components of the turbomachine, such as the turbine, comprise a disk. Such a disk conventionally comprises a plurality of cells which open at the outer periphery of the disk so as to house the roots of moving blades.

[0040] In relation to FIGS. 2 to 9, a first embodiment of a turbomachine assembly comprising a turbomachine disk 2 and at least one foil 5 is presented.

[0041] As illustrated, the turbomachine disk comprises a plurality of cells 25 opening at the external periphery of the disk 2.

[0042] Each of these cells 25 is delimited by a base 20 and two side walls 21 extending on either side of the base 20.

[0043] As already described, each of these cells is hollowed out so as to house one of the moving blade roots.

[0044] The principle of the invention is based on the implementation of a foil between the movable blade root and the cell in order to prevent wear of the movable blades and the disc and to guarantee the mechanical integrity of these parts. More precisely, the invention is based on the implementation of a foil which is in contact with the disc and no longer with the movable blade in order to limit the risks of separation by thermal expansion due to that the thermal stresses at the level of the disc are lower than at the level of the moving blade.

[0045] According to the invention, the foil 5 comprises: - a base 50 intended to extend longitudinally along the X axis and configured to be mounted radially opposite the bottom 20 of the cell 25; - two lateral branches 51 each configured to be mounted circumferentially opposite one of the two lateral walls 21 of the cell 25.

[0046] Thus, when the foil is in place in the cell 25, the base 50 is in contact with the bottom 20 and each of the lateral branches 51 is in contact with a lateral wall 21.

[0047] So that the foil 5 is held in position in the cell 25, the foil 5 has means for axially stopping the click 5 in the cell 25.

[0048] According to the invention, the axial stop means 52 of the click 5 in the cell 25 extend in circumferential projection from at least one of the lateral branches 51 and are configured to cooperate with complementary axial stop means 22 of the disc 2.

[0049] Thus, when the foil 5 is in place in the cell 25, the axial stop means 52 of the click 5 in the cell 25 cooperate with complementary axial stop means formed on the surface of the cell 25, and the foil is locked in position.

[0050] Here, each of the cells 25 has complementary axial stop means 22 formed on the surface of these cells 25.

[0051] Generally, at least one of the cells 25 has complementary axial stop means 22 formed on the surface of the cell 25 and capable of cooperating with axial stop means 52 of the click 5 in the cell 25.

[0052] In this embodiment, the axial stop means of the click 5 in the cell 25 comprise two depressions 52 positioned opposite each other, each of the lateral branches 51 carrying one of the two depressions 52.

[0053] According to a variant, the axial stop means of the click in the cell may comprise at least one depression formed on one of the base or the lateral branches and capable of cooperating with a complementary depression formed on one of the bottom or the lateral walls.

[0054] For example, one could provide a depression taking the form of an anchoring point formed on the base and capable of cooperating with a complementary depression formed on the base.

[0055] It would also be possible to provide a plurality of depressions formed on each of the lateral branches and capable of cooperating with complementary depressions formed on each of the lateral walls.

[0056] One or more depressions could also be provided on at least one of the base and the lateral branches and serving as indexing means. For example, a non-centered depression on the base or on one of the lateral branches, or several non-symmetrical depressions can serve as indexing means.

[0057] According to different embodiments, the depressions 52 are formed by stamping or by machining.

[0058] Similarly, according to different embodiments, the complementary axial stop means comprise at least one depression formed by stamping or by machining.

[0059] In the illustrated embodiment, the axial stop means of the click 5 in the cell 25 therefore comprise two depressions 52 positioned opposite each other, each of the lateral branches 51 carrying one of the two depressions 52.

[0060] These two depressions 52 each have a plane of symmetry.

[0061] These two depressions are pressed towards the outside of the foil 5 and have a semi-oval shape, and more precisely a rectangular semi-oval. Their edges are rounded here.

[0062] According to other embodiments, and as developed above, recesses having other shapes could be provided without departing from the scope of the invention.

[0063] They are each formed on a radially external portion of each of the lateral branches 51 of the foil 5.

[0064] Similarly, the complementary axial stop means 22 comprise two depressions formed hollowly opposite the cell 25.

[0065] More precisely, here, these complementary hollow axial stop means 22 are each formed on a radially external portion of each of the side walls 21.

[0066] These axial stop means may for example be produced by a depression of the lateral branches. Furthermore, the hollow of the complementary axial stop means may open at the radially external end of a tooth of the disc.

[0067] As illustrated, in this embodiment, the axial stop means of the click 5 in the cell 25 extend in a median plane with respect to an axial length of the foil 5.

[0068] Similarly, as also illustrated in this embodiment, the hollow axial stop means extend in a median plane relative to an axial length of the cell 25.

[0069] The fact of implementing axial stop means which extend in a median plane makes it possible to balance the forces exerted both on the foil and on the cell.

[0070] Furthermore, in this embodiment, the base 50 of the foil 5 extends over an entire axial length of the bottom 20 of the cell 25 so as to maximize the bearing surfaces.

Claims

Claims

1. Foil (5) for a disk (2) of axis (X) of a turbomachine (1), intended to be mounted in a cell (25) of the disk (2), radially between the disk (2) and a root of a blade (3), the cell (25) opening at the external periphery of the disk (2) and being delimited by a bottom (20) and two side walls (21) extending circumferentially on either side of said bottom (20), the foil (5) comprising: - a base (50) intended to extend longitudinally along the axis (X) and configured to be mounted radially opposite said bottom (20) of said cell (25);- two lateral branches (51) each configured to be mounted circumferentially opposite one of the two lateral walls (21) of the cell (25), the foil (5) having axial stop means for the click (5) in the cell (25), the axial stop means (52) for the click (5) in the cell (25) extending circumferentially projecting from at least one of the lateral branches and being configured to cooperate with complementary axial stop means of the disc.;

2. Clapper (5) according to claim 1, characterized in that said axial stop means of the click (5) in the cell (25) comprise two depressions (52) positioned opposite each other, each of said lateral branches (51) carrying one of the depressions (52).

3. Foil (5) according to the preceding claim, characterized in that each of the two depressions (52) has a plane of symmetry.

4. Foil (5) according to one of claims 2 or 3, characterized in that each of the depressions (52) is formed by stamping or by machining.

5. Disk (2) of a turbomachine (1) comprising a plurality of cells (25) opening at the external periphery of said disk (2), characterized in that at least one of the cells (25) has complementary axial stop means (22) formed on said surface of said cell (25) and capable of cooperating with axial stop means (52) in the cell (25) of a click (5) according to one of claims 1 to 4 carried by said foil (5).

6. Disk (2) of a turbomachine (1) according to claim 5, in which the complementary axial stop means (22) comprise two depressions formed hollowly opposite the cell (25).

7. Disk (2) of a turbomachine (1) according to the preceding claim, in which the complementary hollow axial stop means are each formed on a radially external end portion of each of the side walls (21).

8. Disk (2) of a turbomachine (1) according to one of claims 6 or 7, in which the complementary hollow axial stop means extend in a median plane with respect to an axial length of the cell (25).

9. Disk (2) of a turbomachine (1) according to one of claims 6 to 8, in which the complementary axial stop means (22) are formed by stamping or by machining.

10. Turbomachine assembly comprising a turbomachine disc (2) according to one of claims 5 to 9, and at least one shim (5) according to one of claims 1 to 4, said axial stop means of the click (5) in the cell (25) extending in circumferential projection from at least one of the lateral branches (51) and cooperating with the complementary axial stop means of the disc (2) formed in a hollow opposite the cell (25).

11. Turbomachine assembly according to the preceding claim, in which the base (50) of the foil (5) extends over an entire axial length of said bottom (20) of said cell (25).

12. A turbomachine turbine comprising an assembly according to one of claims 10 or 11.

13. A turbomachine comprising a turbine according to claim 12.

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