ASSEMBLY COMPRISING AN AXIAL STOP SEGMENT AND A TOOL FOR UNLOCKING SAID AXIAL STOP SEGMENT AND METHOD FOR UNLOCKING AN AXIAL STOP SEGMENT TECHNICAL FIELD OF THE INVENTION

Abstract

Assembly (1) comprising an axial stop segment (2); an unlocking tool (3) for said axial stop segment (2), said axial stop segment (2) comprising: an axial retention ring (5) extending circumferentially in the shape of an arc of a circle relative to an axis X and comprising a folding region (101); a tab (100) movable relative to the folding region (101) between an unlocked position and a locked position, said assembly (1) being characterized in that the unlocking tool (3) comprises: a rod (31), a first branch (33) extending from the rod (31) and a second branch (32) extending from the rod (31), wherein said first branch (33) is in contact with the first surface of the tab (100), said second branch (32) is in contact with the second face of the retention ring. Figure to be published with the abstract: Figure 7

Description

Title of the invention: ASSEMBLY COMPRISING AN AXIAL STOP SEGMENT AND AN UNLOCKING TOOL SAID AXIAL STOP SEGMENT AND METHOD FOR UNLOCKING AN AXIAL STOP SEGMENT TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of aeronautics and particularly to the field of a tool for dismantling a stop segment of a turbine wheel.

[0002] The present invention relates more particularly to an assembly comprising an axial brake segment and a tool for unlocking the axial brake segment. Another aspect of the invention relates to a turbine wheel comprising the assembly according to the invention. The invention further relates to a method for unlocking an axial brake segment. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Conventionally, a turbomachine turbine for aircraft comprises several successive turbine wheels rotating along an axis of rotation X crossed by an air stream.

[0004] As shown in an axial section including the axis of rotation X, in [Fig. 1], a turbine wheel 10 of a turbomachine comprises a plurality of movable blades 12 comprising blade roots 14 and a disk 4 with an axis of rotation X. Each blade root 14 comprises an upstream face and a downstream face axially opposite the upstream face. The disk 4 comprises teeth, not visible, each delimited by an upstream face and a downstream face, and cells 26 formed between the teeth, distributed over the external periphery of the disk 4. Each blade root 14 is mounted in a cell 26 of the disk 4.

[0005] Generally, each blade root 14 is held axially in the cell 26 of the disk 4 by means of a retaining device or axial stop segment 2 or axial brake segment comprising an axial retention ring 5 arranged to bear against the disk 4 and cooperating with a blade hook 7' arranged in the blade root 14. This type of axial stop segment 2 of the blade root 14 requires the presence of a groove or a movable ring forming a groove 23 with the disk, configured to accommodate the axial retention ring 5 and to keep it bearing against the disk 4, opposite the downstream face of a tooth. In other words, the axial stop segment 2 comprises a first face facing the disk 4 and a second face opposite the first face.

[0006] The assembly of the axial stop segments 2 is illustrated in Figures 2 and 3. Each axial stop segment 2 comprises notches 21, 22 and a tab 100 folded into an unlocked position PO relative to the rest of the axial stop segment 2. [Fig. 2] illustrates how the notches 21, 22 of the axial stop segment 2 in the unlocked position PO (referenced in [Fig. 5]) are placed opposite the blade hooks 6', 7' allowing the passage of the axial stop segment 2 into the groove 23 of the disc 4. A translation of each axial stop segment 2 in the groove 23, in the circumferential direction or along the periphery of the disc 4, is then carried out in order to align the corresponding blade hooks 7' with the teeth 6, 7 of each axial stop segment 2, as illustrated in [Fig. 3].

[0007] Finally, the tabs 100 of the axial stop segments 2 are unfolded into a locking position PI, to block the translation of the segments in the groove of the disc. The transition from the unlocked position PO to the locked position PI is illustrated in [Fig. 5] which shows a sectional view of the axial stop segment 2 brake housed in the disc 4, the section being made at the level of a tab 100. It is obvious that in the locked position, the tab 100 is in circumferential abutment with a blade hook, so as to block the translation of the brake segment along the groove of the disc.

[0008] For disassembly, it is sufficient to fold back the tabs 100 of the axial stop segments 2 and to carry out the other operations in reverse order. For example, it is possible to use a tool 19 such as that shown in [Fig.6].

[0009] However, the implementation of such a tool 19 is time-consuming.

[0010] The support areas concerned on a blade 12 are generally fragile and can cause damage requiring replacement of blade 12. Pressing on disc 4 will not be acceptable if it generates a mark because it is a critical part of the engine.

[0011] There is currently no known tool that allows an axial brake segment to be quickly unlocked without risk of damaging the segment itself, the disc or the blade roots. Summary of the invention

[0012] The invention provides a solution to the problems mentioned above, by proposing an assembly comprising an axial stop segment with a foldable tab and an unlocking tool allowing the tab to be folded by lever arm without coming into contact with other parts of the turbine wheel.

[0013] A first aspect of the invention relates to an assembly comprising an axial stop segment comprising at least one tooth for forming an axial stop of at least one blade root and a tool for unlocking said axial stop segment, said axial stop segment comprising: • an axial retention ring having a first face and a second face opposite the first face, said axial retention ring extending circumferentially in the shape of an arc of a circle relative to an axis X and comprising a folding region; • a tab movable relative to the folding region between a locked position and an unlocked position, said tab extending from the folding region of the axial retention ring to a free end in a radial direction normal to the X axis, said tab having a first surface and a second surface opposite the first surface,

[0014] said assembly being characterized in that the unlocking tool comprises: • a stem, • a first branch extending from the stem and • a second branch extending from the stem, • wherein said first branch is in contact with the first surface of the tab at a first point of contact, said second branch is in contact with the second face of the axial retention ring at a second point of contact, the first point of contact being located radially outwardly relative to the second point of contact.

[0015] The first face of the axial stop segment is understood to be the face of the segment facing the blade roots or a disc intended to accommodate the blade roots. The second face of the axial stop segment is understood to be the face opposite the internal face.

[0016] The term "first surface of the tongue" means the surface of the tongue which is at least partially opposite the blade roots or a disc intended to accommodate the blade roots. The term "second surface of the tongue" means the surface of the tongue opposite the internal surface.

[0017] The assembly according to the invention makes it possible to effectively bend the tab without touching any other element of the turbine wheel and therefore to reduce the risk of damage to adjacent parts.

[0018] The unlocking tool allows the tab to be bent only by pressing at two points on the segment itself and only it, like a bottle opener. This greatly reduces the risk of damaging the blades or the disc.

[0019] The first internal and second branches of the unlocking tool are sized to avoid any contact with parts other than the tab such as the blade roots or the disc.

[0020] In other words, the unlocking tool behaves like an inter-support or first-class lever. The second point of contact at the outer face of the axial stop segment constitutes the fulcrum of the lever. The first point of contact at the inner surface of the tab represents the force which opposes when bending the free end of the tab. The force exerted on the rod allows the tab to be bent into the unlocked position. Increasing the length of the rod of the unlocking tool therefore reduces the force required to bend the tab.

[0021] According to one embodiment, the second point of contact is located at said folding region. According to this embodiment, the unlocking tool rests only on the tab. This makes it possible to greatly reduce the risk of damaging the blades, the disc or other parts of the axial stop segment.

[0022] According to a variant of this embodiment, said second branch comprises two arms in contact with two second contact points of the second face of the retention ring, the folding region being located between the two contact points.

[0023] According to another variant of these two embodiments, the second point of contact is radially internal relative to the folding region.

[0024] Advantageously, the axial stop segment comprises two teeth, each tooth extending from the axial retention ring to a free end in a radial direction normal to the X axis, each tooth comprising a stop portion extending from the free end and having a thickness to be housed in a blade hook so as to axially stop the corresponding blade root.

[0025] Advantageously, the tab is located between the two teeth.

[0026] Advantageously, the rod of the unlocking tool extends in a direction normal to the second surface of the tab; this orientation of the rod makes it possible to reduce the force required to position the tab in the unlocked position. Of course, another angle between the rod and the tab may work but would be less efficient.

[0027] Advantageously, the radial distance between the first point of contact and the free end of the tab is less than the radial distance between the first point of contact and the folding zone. This makes it possible to reduce the force required to place the tab in the unlocked position. In other words, the first point of contact is as close as possible to the tab.

[0028] Advantageously, the second branch has a first portion extending from the rod, and a second portion extending from the first portion, the second portion having one end forming contact with the second face of the axial retention ring, the angle between the first portion and the second portion being greater than or equal to 90 degrees.

[0029] This makes it possible to increase the distance between the fulcrum of the lever arm and the point of application of the force at the free end of the tab. In other words, this arrangement of the unlocking tool makes it possible to subsequently reduce the force required to put the tab in the unlocked position.

[0030] A second aspect of the invention relates to a turbine wheel comprising: • a disk with an X rotation axis, • a plurality of blades, each blade comprising a blade root mounted in a cell of the disc, • the assembly according to the preceding aspect of the invention, the segment extending circumferentially along the periphery of the disc and a portion of the axial retention ring being housed between two walls of the disc.

[0031] Another aspect of the invention relates to a method for axially unlocking blade roots on a disc, each blade root comprising a hook, the disc comprising disc teeth and cells in which the blade roots are mounted, each blade root being axially locked by an axial stop segment comprising: • At least one tooth to form an axial stop of at least one blade root; • An axial retention ring having a first face and a second face opposite the first face, said axial retention ring extending circumferentially in the shape of a circle relative to an axis X and comprising a folding region; • A tab movable relative to the folding region between an unlocked position and a locked position, said tab extending from the folding region of the axial retention ring to a free end in a radial direction normal to the X axis, said tab having a first surface and a second surface opposite the first surface;

[0032] the at least one tooth extending from the axial retention ring to a free end in a radial direction normal to the X axis and comprising a stop portion extending from the free end and housed between the hook and the blade root so as to axially stop the blade root;

[0033] said method comprising the following steps: • Positioning (401) of an unlocking tool (3), said locking tool comprising: - A rod (31); - A first branch (33) extending from the rod (31) and - A second branch (32) extending from the rod (31),

[0034] the first branch (33) being in contact with the first surface of the tongue (100) at a first point of contact (330), the second branch (32) being in contact with the second face of the axial retention ring (5) at a second point of contact (320), the first point of contact (330) being located radially outwards relative to the second point of contact (320); • Applying force to the rod of the unlocking tool to modifying the inclination of the tab relative to the axial retention ring until the free end of the tab is in the unlocked position so as not to be in circumferential abutment with the blade hook; • Circumferential translation of the axial stop segment along the periphery of the disc so as to have at least one tooth of the axial stop segment between two hooks. • Extraction of the axial stop segment from the disc.

[0035] The unlocking method according to the invention has the advantage of being simple to implement and of reducing the risks of damage to the parts adjacent to the tab.

[0036] The inclination of the tongue is understood to mean the angle formed by the tongue and the plane along which the axial stop segment extends.

[0037] Advantageously, the method according to one aspect of the invention comprises a fourth step of extracting the axial stop segment. This makes it possible to separate the axial brake segment from the blade disc.

[0038] In one embodiment of the method according to one aspect of the invention, the unlocking tool extends in a direction normal to the external surface of the tab.

[0039] In one embodiment of the method according to one aspect of the invention, the radial distance between the first point of contact and the free end of the tab is less than the radial distance between the first point of contact and the second point of contact.

[0040] In one embodiment of the method according to one aspect of the invention, the second branch has a first portion extending from the rod and a second portion extending from the first portion, the second portion having one end forming contact with the second face of the axial retention ring, the angle between the first portion and the second portion being greater than or equal to 90 degrees.

[0041] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0042] Other advantages and characteristics of the invention will appear on reading the following description, illustrated by the figures in which:

[0043] [Fig. 1] is an axial sectional view of a turbine wheel comprising a retaining device according to the state of the art;

[0044] [Fig.2] is a partial perspective view of the upstream face of a turbine wheel having an axial brake segment according to the state of the art;

[0045] [Fig.3] is a second partial perspective view of the downstream face of a wheel of turbine of [Fig.2] illustrating the longitudinal translation of an axial brake segment according to the state of the art;

[0046] [Fig.4] is an enlarged view of a portion of the retaining device of [Fig.3] illustrating the folding of the tab into the locked position;

[0047] [Fig. 5] is an axial sectional view of a brake segment according to the state of the art. illustrating the two locked and unlocked positions of the tab.

[0048] [Fig.6] is a sectional view of an unlocking tool according to the state of the technique;

[0049] [Fig.7] is a partial perspective view of the assembly according to the first aspect of the invention;

[0050] [Fig.8] is an enlarged view of the assembly according to the first aspect of the invention;

[0051] [Fig.9] is an axial section of the assembly according to the first aspect of the invention illustrated in Figures 7 and 8;

[0052] [Fig. 10] schematically illustrates the steps of the method according to one aspect of the invention. DETAILED DESCRIPTION

[0053] An exemplary embodiment of a turbine wheel comprising a brake segment unlocking assembly according to the first aspect of the invention is described in detail below, with reference to the appended drawings. This example illustrates the characteristics and advantages of the invention.

[0054] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0055] For the understanding of the invention, the radial R, tangential or circumferential T and axial A orientations will be adopted according to the reference RT A indicated in the figures, the tangent T and axial A axes of which extend in a horizontal plane according to the orientation in the figures. The axial axis A is parallel to an axis of rotation X of a disk of the turbine wheel. The upstream of the device towards the downstream of the retaining device is oriented according to the axial axis of the reference RTA. In addition, the term longitudinal will be used for the direction extending along the periphery of the disk, by analogy with the terminology used in cylindrical coordinate reference systems.

[0056] In the description, the terms “upstream” and “downstream” are defined in relation to the direction of air flow from the air inlet into the turbine to the air outlet from the turbine.

[0057] [Fig.l] to [Fig.6] have been described in relation to the state of the art.

[0058] [Fig.7] and [Fig.8] represent an enlarged view of a turbine wheel comprising: - a disc 4 with rotation axis X comprising teeth and alveoli formed between the teeth, - a plurality of blades (not visible in the figure) each comprising a blade root mounted in a corresponding cell of the disc 4, and - an assembly 1 according to an embodiment of a first aspect of the invention comprising an axial stop segment 2 of at least one blade root to hold it in the cell of the disc and a tool 3 for unlocking the axial brake segment 2.

[0059] Each tooth of the disc 4 comprises an upstream face and a downstream face axially opposite the upstream face and axially connected by a lateral face of the tooth. Each cell of the disc 4 is delimited by two lateral faces of the tooth 32 opposite circumferentially or longitudinally relative to each other and connected circumferentially or longitudinally by a bottom of the cell. The bottom of the cell is therefore a surface of the disc 4 arranged between two lateral faces of two neighboring teeth.

[0060] [Fig.7] illustrates an example of an assembly 1 according to the first aspect of the invention. The assembly 1 comprises a brake segment 2 and an unlocking tool 3. The brake segment 2 extends circumferentially along the periphery of the disc 4. The brake segment 2 comprises the axial retaining ring 5 having a first face or internal face facing the disc and a second face or external face opposite the first face. The brake segment 2 further comprises a series of teeth 6, 7, 8, 9 extending radially from the axial retaining ring 5 in radial directions of the disc. In the locked position, each tooth faces a blade hook 6', 7', 8', 9' so as to axially block the blade roots mounted on the disc 4.

[0061] The brake segment 2 comprises a tab 100 comprising a first surface or internal surface and a second surface or external surface. The tab 100 is positioned between two teeth 7 and 8 and extends from the axial retention ring 5 to a free end in a radial direction normal to the axis X. In the locked position, the free end of the tab 100 is in circumferential or tangential abutment against a blade hook 7' or 8'.

[0062] According to the first embodiment illustrated in [Fig.7], the axial retention ring 5 comprises a folding region 101 connecting the axial retention ring 5 to the tab 100.

[0063] The assembly 1 further comprises an unlocking tool 3. The unlocking tool 3 comprises a rod 31 connected to a first branch 33 and to a second branch 32. In this first embodiment, the rod 31 of the unlocking tool 3 extends in a direction normal to the second surface of the tab 100.

[0064] According to the embodiment illustrated in [Fig.7], the unlocking tool 3 rests only on the tab 100 and on the folding region 101. This makes it possible to greatly reduce the risk of damaging the blades, disc or other parts of the brake segment.

[0065] [Fig. 8] shows an enlarged view of a turbine wheel according to [Fig. 7] comprising an assembly 1 according to the first aspect of the invention. [Fig. 8] shows that the first internal 33 has one end in contact with the first surface of the tongue at a first contact point 330. The second branch 32 has one end in contact with the folding region 101 at a second external contact point. The first contact point 330 is radially external relative to the second contact point 320.

[0066] Advantageously, this configuration makes it possible to bend the tab 100 at the bending region 101 by exerting a force at the rod 31 of the unlocking tool 3.

[0067] The first branch 33 and the second branch 32 have a reduced size, which allows the unlocking tool 3 to be used without touching the adjacent parts, while reducing the risk of damaging them.

[0068] According to the embodiment illustrated in figures [Fig.7] and [Fig.8], the circumferential extension of the two branches 32 and 33 is less than the circumferential extension of the tab 100, so as not to be in contact with the teeth 6,7 of the brake segment 2 during unlocking.

[0069] According to the embodiment illustrated in [Fig.7] and [Fig.8], the axial extension of the internal branch is less than the distance between the first surface of the tab and the blade root opposite the first surface of the tab. This makes it possible to unlock the brake segment 2 without risking touching the blade roots.

[0070] According to the embodiment illustrated in [Fig.7] and [Fig.8], the rod 31 extends along a direction substantially normal to the second face of the tongue 100.

[0071] Figure [Fig.9] shows an axial sectional view of the assembly according to the first aspect of the invention, the section being made at the level of the tab 100. According to the embodiment illustrated in [Fig.9], the second branch 32 has a first part 321 connected to the rod 31, and a second part 322 connected to the first part 321 and having one end in contact with the folding region 101. The contact between the second part 322 and the second face of the retention ring is made at a second contact point 320, the angle between the first branch and the second branch being greater than or equal to 90 degrees.

[0072] The angle 0 illustrated in [Fig.9] designates the bending angle of the tab 100 or its inclination, namely the angle between the tab 100 and the plane along which the axial retention ring 5 extends.

[0073] This arrangement makes it possible to shift the fulcrum of the lever along the rod 31 relative to the first contact point 330 or internal contact point. Given that the first point of contact 330 is the point of application of the force to bend the tab, this arrangement makes it possible to reduce the force required to bend the tab 100 by unlocking the brake segment 2.

[0074] The position of the unlocking tool 3 in a continuous line corresponds to the locked position of the tab 100, which is then in circumferential abutment against a lateral face of a hook adjacent to the tab 100. The bending angle 0 can also be defined as the angle between the first face of the tab 100 and the plane of rotation of the disc 4.

[0075] The position of the unlocking tool 3 in dashes corresponds to the unlocked position of the tab 100. The unlocked position corresponds to a higher angle 0 compared to the locked position.

[0076] It is important to note how the unlocked position in figure [Fig.9] corresponds to a brake segment 2 which is free to translate along the disc 4 because the free end of the tab 100 is no longer in circumferential abutment against a lateral face of a hook.

[0077] Figure [Fig. 10] schematically illustrates the steps of the method 400 according to the fourth aspect of the invention. The method 400 comprises a step 401 of positioning a tool for unlocking an assembly according to the first aspect of the invention. During this step, the first branch is in contact with the first surface of the tab at a first point of contact or internal point of contact. The second branch is positioned in contact with the second face of the axial retention ring at a second point of contact or external point of contact. Advantageously, the first point of contact is radially external relative to the second point of contact. This arrangement makes it possible to reduce the force required to bend the tab and place it in the unlocked position.

[0078] The method 400 further comprises a step of applying a force 402 to the rod 31 of the unlocking tool to modify the inclination of the tab relative to the retention ring, until the free end of the tab is in the unlocked position. This step corresponds to the change between the locked and unlocked position illustrated in the figure [Fig.9].

[0079] At the end of step 403, the free end of the tongue is no longer in circumferential abutment with a hook, which allows the circumferential or longitudinal translation of brake segment 2 during step 403.

[0080] The translation of the brake segment allows each tooth of the brake segment to be opposite a tooth of the disc.

[0081] The method 400 according to the invention may further comprise a step 404 of extracting the brake segment from the disc.

[0082] Advantageously, the method 400 according to one aspect of the invention makes it possible to reduce the risk of damaging adjacent parts and save time in after-sales operations.

[0083] It is interesting to estimate the time saving compared to the use of the unlocking tool according to the state of the art.

[0084] The installation, use and uninstallation time of the current tooling is estimated at 5 minutes. For example, there are 7 tabs to be folded in a LEAP-1A / 1C type turbine. The assembly according to the first aspect of the invention can be used in just a few seconds, since there is no installation required.

Claims

Claims

1. Assembly (1) comprising an axial stop segment (2) comprising at least one tooth for forming an axial stop of at least one blade root and an unlocking tool (3) for said axial stop segment (2), said axial stop segment (2) comprising: - an axial retention ring (5) having a first face and a second face opposite the first face, said axial retention ring (5) extending circumferentially in the shape of an arc of a circle relative to an axis X and comprising a folding region (101); - a tab (100) movable relative to the folding region (101) between an unlocked position and a locked position, said tab (100) extending from the folding region (101) of the axial retention ring (5) to a free end in a radial direction normal to the X axis, said tab (100) having a first surface and a second surface opposite the first surface,- said assembly (1) being characterized in that the unlocking tool (3) comprises: - a rod (31), - a first branch (33) extending from the rod (31) and - a second branch (32) extending from the rod (31), wherein said first branch (33) is in contact with the first surface of the tab (100) at a first point of contact (330), said second branch (32) is in contact with the second face of the retention ring at a second point of contact (320), the first point of contact (330) being located radially outwardly relative to the second point of contact (320).,

2. Assembly (1) according to the preceding claim characterized in that the second point of contact (320) is located at the level of said folding region (101).

3. Assembly (1) according to one of the preceding claims, characterized in that the rod (31) of the unlocking tool (3) extends according to a direction normal to the second surface of the tab (100).

4. Assembly (1) according to one of the preceding claims, characterized in that the radial distance between the first point of contact (330) and the free end of the tongue is less than the radial distance between the first point of contact (330) and the second point of contact (320).

5. Assembly (1) according to one of the preceding claims, characterized in that the second branch (32) has a first part (321) extending from the rod (31) and a second part (322) extending from the first part (321), the second part (322) having one end forming contact with the second face of the axial retention ring (5), the angle between the first part (321) and the second part (322) being greater than or equal to 90 degrees.

6. Turbine wheel comprising: - a disc (4) with an axis of rotation X, - a plurality of blades, each blade comprising a blade root mounted in a cell of the disc, - the assembly (1) according to one of the preceding claims, the segment extending circumferentially along the periphery of the disc and a portion of the axial retention ring (5) being housed between two walls of the disc.

7. Method (400) for axially unlocking blade roots on a disc (4), each blade root comprising a hook (6', 7', 8', 9'), the disc (4) comprising disc teeth and sockets in which the blade roots are mounted, each blade root being axially locked by an axial stop segment (2), said axial stop segment comprising: - at least one tooth (6, 7, 8, 9) for forming an axial stop of at least one blade root; - an axial retention ring (5) having a first face and a second face opposite the first face, said axial retention ring (5) extending circumferentially in the shape of a circle relative to an axis X and comprising a folding region (101); - a tab (100) movable relative to the folding region (101) between an unlocked position and a locked position, said tab (100) extending from the folding region folding (101) of the axial retention ring (5) to a free end in a radial direction normal to the X axis, said tab (100) having a first surface and a second surface opposite the first surface; the at least one tooth (6, 7, 8, 9) extending from the axial retention ring (5) to a free end in a radial direction normal to the X axis and comprising a stop portion extending from the free end and housed between the blade hook (6', 7', 8', 9') and the blade root so as to axially stop the blade root; said method comprising the following steps: Positioning (401) of an unlocking tool (3), said locking tool comprising: • A rod (31); • A first branch (33) extending from the rod (31) and • A second branch (32) extending from the rod (31), the first branch (33) being in contact with the first surface of the tab (100) at a first point of contact (330), the second branch (32) being in contact with the second face of the axial retention ring (5) at a second point of contact (320), the first point of contact (330) being located radially outwardly relative to the second point of contact (320); Applying a force (402) to the rod (31) of the unlocking tool to modify the inclination of the tab (100) relative to the axial retention ring (5) (5) until the free end of the tab (100) is in the unlocked position so as not to be in circumferential abutment with the blade hook; Circumferential translation (403) of the axial stop segment (2) along the periphery of the disc (4) so as to have the at least one tooth (6, 7, 8, 9) of the axial stop segment (2) between two hooks. Extraction (404) of the axial stop segment (2) from the disc.

8. Method according to the preceding claim in which the rod (31) of the unlocking tool (3) extends in a direction normal to the external surface of the tab (100).

9. A method according to claim 8 or claim 9 wherein the radial distance between the first contact point (330) and the free end of the tab is less than the radial distance between the first contact point (330) and the second contact point (320).

10. Method according to one of claims 7 to 9 in which the second branch (32) has a first part extending from the rod (31) and a second part (321) extending from the first part (321), the second part (322) having one end forming contact with the second face of the axial retention ring (5), the angle between the first part (321) and the second part (322) being greater than or equal to 90 degrees.

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