Turbomachine rotor assembly and turbomachine

Abstract

One aspect of the invention relates to a rotor assembly of a turbomachine, comprising a disc (2) of axis X comprising pockets (20), comprising a longitudinal direction (x') for the insertion of a blade root (32), inclined with respect to a straight line d parallel to the axis X and passing through the pocket (20). The assembly comprises at least one plate (4) in the pocket (20), comprising a main portion (40) located in the pocket (20) and two anti-rotation parts (421, 431) on respective sides of the main portion (40), respectively pressed against the second radial surface (23) of the disc (2) and intended to come into contact with a blade root (32), characterized in that the two anti-rotation parts (421, 431) are passed through by a plane (P(d,x)) comprising the straight line d and the axis of rotation X, and in that a width (L42, L43) of at least one anti-rotation part (421, 431), measured perpendicularly to the radial and axial directions, is wider than a width (L1) of the main portion (40).

Description

DESCRIPTION TURBOMACHINE ROTOR ASSEMBLY AND TURBOMACHINE TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of turbomachines such as turboprops or turbojets. More particularly, the invention relates to an axial stop plate for a turbomachine rotor, as well as a rotor assembly equipping such a turbomachine. It essentially aims at the axial locking of the fan blades in their housing on the fan disc. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] A turbomachine rotor, for example a rotor implemented in a low-pressure turbine extending around a longitudinal axis and conventionally comprising one or more rotor discs carrying on the outer periphery a plurality of moving blades.

[0003] The moving blades have a radially internal part, or blade root, extended by a blade. These moving blades are each housed at their root in one of the cells of the disc which open onto the outer peripheral surface of the rotor disc. The positioning of the blade roots in the cells of the rotor discs is done by translation in a cell direction inclined from 0 to 30° relative to the axis of the turbomachine.

[0004] In order to facilitate the assembly of the moving blades on the rotor disks, it is necessary to provide sufficient clearance to allow easy sliding of the blade roots in the cells. There therefore remains a relatively large clearance once the blade root has been assembled in the cell, which requires an axial retaining device retaining a blade root or blade roots, such as flanges mounted and wedged on each side of the blade and the disk or axial wedges each arranged in the corresponding cell to retain the blade in the cell in an axial direction.

[0005] There are axial stop plates with a small width between 1 and 50mm, and a small thickness between 0.3mm and 5mm, in order to allow the maximum amount of air to pass through the gap between the blade root and the base of the cell in order to cool the blade root. In fact, when of the rotation of the rotor each blade root is subjected to high temperatures during the operation of the turbomachine, due to the blades arranged in the flow path of the low pressure turbine crossed by gases whose temperature is high. The cells of the disks which receive the blade roots being directly exposed to these gases, it may be necessary to cool them to avoid any damage to the disks. For this purpose, it is known in particular to take a portion of the air which flows outside the flow path of the low pressure turbine to convey it via a cooling circuit to the cells of the rotor disks either by channels in the disk as in the applicant's application FR3054855, or by a fresh air flow channel formed between a cylindrical flange mounted axially against the blade root and the disk to bring air between the blade root and the bottom of the disk cell.The flange can also be used to hold the blade root in the other axial direction.

[0006] Figure 1A represents an axial view of an assembly in the case of a narrow axial stop plate 1 comprising a main portion 10 housed in a cell 20 of a disc 2 between the bottom of the cell 20 and a blade root 32 of a blade 3. Two blades 3 are represented in this figure 1A, they each comprise a blade 30, a platform 31 extending from the blade 30 and the blade root 32 extending from the platform 31 housed in the cell 20 between two teeth 21 of the disc 2. The axial stop plate 1 is further represented in figure 1B representing the axial stop plate 1 in a three-dimensional manner.

[0007] The axial stop plate 1 thus comprises a main portion 10 housed in and along the cell 20 and a first longitudinal end portion 13 for axially holding the blade 3, extending from a first end of the main portion 13 outside the cell 20 in abutment against a radial surface of the blade root 32 to retain it axially in an axial direction. In this figure 1A, a first radial face 23 of the disc 2 is shown, the longitudinal end portion 13 of which is visible. The stop plate 1 further comprises a second longitudinal end portion 12 for axial retention against a second radial surface (not visible) of the disc 2 extending from one end of the main portion 13 opposite the first end.

[0008] However, the axial stop plate 1 can become misaligned relative to the direction x' of the cell 20. Figures 2A and 2B schematically represent respectively an axial stop plate 1 housed and centered in a cell 20 in the inclined direction x' of the cell 20 relative to the axis of rotation x and an axial stop plate 1 housed and offset in the worst case in the cell 20 relative to the inclined direction x' of the cell 20. Here the direction x' of the cell 20 is at an angle of 21° relative to the axis of rotation x. The direction x' and the axis of rotation x each extend in two parallel planes. In Figure 2A, the axial stop plate 1 protrudes from the disc 2 only by its thickness e representing the second longitudinal end portion 12 against the radial surface of the disc 2. Of course, the first longitudinal end portion 13 can also protrude from the disc 2 if the radial surface of the blade root 3 is flush with a radial surface of the disc 2 opposite that in abutment.As seen in Figure 2B, each axial stop plate 1 comprises a width L1 measured perpendicular to the insertion direction x'. Due on the one hand to the fact that the width L1 is less than a width L2 of the bottom of the corresponding cell 20 housing the main portion 10 opposite an end surface of the blade root 21, and on the other hand to the inclination of a few degrees (here 21°) of the insertion direction x' of each cell 20 relative to the axis of rotation x, each axial stop plate 1 can pivot, here according to an angle of 6° measured between the longitudinal direction x” of the axial stop plate 1 and the insertion direction x' of the cell 20. This pivoting causes an axial projection L3, L4 of the axial stop plate 1 relative to the disc 2 on each side which can cause a displacement by a distance L5 according to the translation direction x' of the blade root 32.This distance L5 of displacement of the blade root 32 and the axial stop plate 1 can cause turbulence reducing the efficiency of the turbomachine as well as damage to the blade 3 and the axial stop plate 1.

[0009] In Figure 1B an axis d is shown, passing at the middle of the main portion of the axial stop plate 1. This axis d is parallel to the axis X of rotation. The axis d passes at the middle of the axial stop plate 1 in a radial plane p(d,x) further comprising the axis of rotation x.

[0010] Figure 1C represents the view of the axial stop plate 1 according to an axial view along the rotation axis X as well as in dotted lines the plane p(d,x) comprising the rotation axis x and the axis d.

[0011] There is therefore a need to prevent a narrow axial stop plate from pivoting. SUMMARY OF THE INVENTION

[0012] The invention provides a solution to the problems mentioned above, by proposing an axial stop plate, the plate is held angularly using an overlap of the longitudinal end portions according to an axial view of the rotor.

[0013] One aspect of the invention relates to a turbomachine rotor assembly, comprising: a rotation axis disc, comprising: a first and a second radial surface axially opposite relative to the disc, teeth at the radially outer periphery of the disc, connecting the first radial surface to the second radial surface and cells each delimited by two circumferentially adjacent teeth, each cell extending from a first axial end edge which connects the cell to the first radial surface to a second axial end edge which connects the cell to the second radial surface, each cell comprising a longitudinal direction for the insertion of a blade root, which is preferably inclined relative to the rotation axis, a plate intended to hold in a single axial direction a blade in one of the cells, comprising: a main portion mounted in the cell,the main portion extending in the longitudinal direction between a first longitudinal end and a second opposite longitudinal end, comprising a width measured perpendicular to the longitudinal direction and the radial direction, a first longitudinal end portion and a second longitudinal end portion extending axially on either side of the main portion, the first longitudinal end portion and the second longitudinal end portion, each comprising an anti-rotation part, the anti-rotation part of the first longitudinal end portion cooperating with the second radial surface of the disc located radially between a bottom of the cell and the axis of rotation and the anti-rotation part of the second longitudinal end portion being intended to cooperate with a root of a blade, characterized in that at least one anti-rotation part has a width taken perpendicular to the radial and axial direction, wider than the width taken perpendicular to the radial and axial direction, of the main portion.

[0014] By virtue of the invention, the fact that an anti-rotation portion has a width taken perpendicular to the radial and axial direction, wider than the width taken perpendicular to the radial and axial direction, of the main portion makes it possible to reduce or even prevent, depending on its width and the half-width of the cell, pivoting of the plate in the cell. In addition, the fact of locating the anti-rotation portion of the first longitudinal end portion cooperating with the second radial surface of the disc situated radially between the cell and the axis of rotation makes it possible to avoid having plates covering the blade root on each axial side.

[0015] In addition to the characteristics which have just been mentioned in the preceding paragraph, the plate according to one aspect of the invention may have one or more additional characteristics among the following, considered individually or according to all technically possible combinations: According to one embodiment, the first longitudinal end portion extends radially from the end of the main portion towards the axis of rotation, and the second longitudinal end portion extends radially from the other end of the main portion towards the outside. According to one embodiment, the first radial surface of the disc is an upstream radial surface and in which the second radial surface of the disc is a downstream radial surface. According to one embodiment, each anti-rotation portion extends only on one side relative to the rest of the first, second longitudinal end portion, respectively, the first, second end portion longitudinal comprising an edge located in the same plane as an edge of the main portion. According to one embodiment, the width taken perpendicular to the radial and axial direction, of each of the two anti-rotation parts extends in a plane normal to the axis of rotation. Thus, the anti-rotation parts extend in a circumferential direction to prevent rotation of the insert. This makes it possible to balance the weight of the longitudinal end portion. In other words, a plane normal to the axis of rotation which passes through the two longitudinal end portions, results in an overlap of the two longitudinal end portions according to an axial view. In other words, by locating the axis d radially at the level of the anti-rotation parts in the cell, this axis d parallel to the axis of rotation X (same direction) will pass through the anti-rotation parts, thus making it possible to prevent the pivoting of the insert in the cell. According to an example of this embodiment, the plane passes through the axial and circumferential center of the cell. According to one embodiment, the first longitudinal end portion and the second longitudinal end portion of the plate are of identical shape. According to one embodiment, the first longitudinal end portion and the second longitudinal end portion are of the same dimension. This makes it possible to have a symmetrical longitudinal end portion and thus to be able to manufacture longitudinal end portions more easily and in particular less expensively by cutting sheets while reducing losses. According to one embodiment, the maximum width of the main portion taken perpendicular to the radial and axial direction is at least twice smaller than the width of the cell, taken perpendicular to the radial and longitudinal direction. This makes it possible to form cooling channels and to reduce the weight of the plates. According to one embodiment, the maximum width of the main portion taken perpendicular to the radial and axial direction is at least two times smaller than a width of the cell, taken perpendicular to the radial and axial direction. According to one embodiment: the first longitudinal end portion comprises a first bend extending from the main portion to the anti-rotation part of the first longitudinal end portion, the second longitudinal end portion comprises a second bend extending from the main portion to the anti-rotation part of the second longitudinal end portion, in which the first bend and second bend each have a maximum width taken perpendicular to the radial and axial direction, less than respectively the maximum width taken perpendicular to the radial and axial direction, of the corresponding anti-rotation part. This makes it possible to have a simple manufacturing insert while having an axial spring effect with the curved fold.According to one example; the first and second longitudinal end portions respectively comprise a first and second intermediate portion each extending between the corresponding fold and the rotation portion. According to one embodiment, the first and second longitudinal end portions respectively comprise a first and second intermediate portion each extending between the corresponding elbow and the anti-rotation part, the first and second intermediate portions each having a width taken perpendicular to the radial and axial direction which widens increasingly from the elbow corresponding to the anti-rotation part. According to one embodiment, each of the anti-rotation parts has a width taken perpendicular to the radial and axial direction, greater than the width taken perpendicular to the radial and axial direction of the main portion. According to one embodiment, each of the anti-rotation parts has a width taken perpendicular to the radial and longitudinal direction of , greater than the width taken perpendicular to the radial and axial direction of the main portion. This makes it possible to simplify the manufacture of the plate and to be able to form two symmetrical longitudinal end portions. According to an example of these last two embodiments of the assembly, the plate is formed from a sheet metal cut and folded to form the first and second longitudinal end portions from the main portion. This makes it possible to simplify the manufacture of the plate. According to one embodiment, the assembly further comprises blades, each comprising a blade root housed in a corresponding cell which opens at the radially external periphery of the disc, each plate comprising: the main portion between the bottom of the corresponding cell and the corresponding blade root, the anti-rotation part which cooperates with a radial surface of the blade root. In this embodiment, the assembly is therefore a mobile wheel of a turbomachine rotor. According to one embodiment, the assembly comprises a plurality of air circuits opening into each cell, this makes it possible to have a plate while allowing the air to circulate. According to one embodiment, the assembly comprises an air circuit opening into at least one cell. In particular according to an example of these two embodiments, the disc comprises this air circuit. Another aspect of the invention relates to a turbomachine comprising a rotor assembly of a turbomachine according to the different aspect with or without a combination of the characteristics of the different embodiments.

[0016] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0017] The figures are presented for information purposes only and in no way limit the invention.

[0018] [Fig. 1A] schematically represents an axial view of an assembly comprising a disc, a blade root and a plate according to the prior art.

[0019] [Fig. 1 B] schematically represents a perspective view of the plate of the assembly of Figure 1 A according to the prior art.

[0020] [Fig. 1 C] schematically represents an axial view of the plate of the assembly of Figure 1 A according to the prior art.

[0021] [Fig. 2A] schematically represents a top view of a plate according to the prior art in a cell.

[0022] [Fig. 2B] schematically represents a top view of the plate of figure 2A according to the prior art offset in the cell.

[0023] [Fig. 3A] schematically represents an axial view of an assembly according to a first example of the first embodiment of the invention, comprising a disc, a blade root and a plate.

[0024] [Fig. 3B] schematically represents an axial view opposite that of FIG. 3A, of the assembly according to the example of the first embodiment of the invention.

[0025] [Fig. 4] represents a perspective view of an axially retained insert according to the example of the assembly of Figure 3A.

[0026] [Fig. 5A] represents a schematic diagram of a top view of a wafer according to Figure 3A in a cell.

[0027] [Fig. 5B] represents a schematic diagram of an axial view of the plate of the assembly of Figure 3A.

[0028] [Fig. 6] represents a perspective view of an axially retained insert according to a second example of the assembly. DETAILED DESCRIPTION

[0029] The figures are presented for information purposes only and in no way limit the invention.

[0030] [Fig. 3A] shows a schematic representation according to an axial view of a part of an assembly according to an example of a first embodiment of the invention.

[0031] The assembly comprises at least one disk 2 of a turbomachine rotor, for example of a turbine, in this case more precisely of a low-pressure turbine stage. The disk 2 is like that described in FIG. 1A, it comprises a first radial surface 23 partially visible in FIG. 3A and a second radial surface 22 axially opposite relative to the disk 2, referenced in FIG. 3B partially schematically representing the assembly of FIG. 3A seen on the other face of the disk 2.

[0032] The disc 2 comprises teeth 21 and alveoli 20 each delimited between two circumferentially adjacent teeth 21, located at the radially external periphery of the disc 2. Thus the disc comprises teeth and alveoli in an alternating manner circumferentially on its external periphery. Each cell 20 extends in a plane parallel to an axis X of rotation not shown in these two figures 3A, 3B, from a first axial end edge 202 which connects the cell 20 to the first radial surface 23 to a second axial edge 203 which connects the cell 20 to the second radial surface 22. The cells 20 are inclined relative to the axis of rotation X but each belong to a plane tangent to a circle of axis of rotation X. A reference xrt is shown whose axis x represents the axial direction which is parallel to the axis of rotation X, the axis r represents the radial direction, and the axis t represents the tangent direction.Each cell 20 thus comprises a longitudinal direction x' shown in Figure 5A schematically representing a top view (i.e. a radial view) of the cell 20 explained below, different from each other around the axis X of rotation but parallel to each other. The longitudinal directions x', each also called inclined longitudinal direction, are therefore in a cylinder of an axis intersecting the axis of rotation X. Each cell 20 thus allows, along this longitudinal direction x', the insertion of a blade root 32, inclined relative to a straight line d (for each cell 20) parallel to the axis X and passing through the corresponding cell 20. The first and second radial surfaces 23, 22 are each perpendicular to the axis of rotation X and to this straight line d.

[0033] The assembly comprises at least one plate 4 in a cell 20, but preferably it comprises as many plates 4 as cells 20. The assembly may further comprise a blade 3 per cell 20 each comprising a blade root 32 in the corresponding cell 20. In Figure 3A only two blades 3, two cells 20 and two plates 4 are shown as well as a tooth 21 and partially two teeth 21. The assembly may be a turbine rotor stage, for example of a low pressure turbine.

[0034] Each plate 4 makes it possible to axially hold a blade 3 in the longitudinal direction x' in the direction of the second radial surface 22 towards the first radial surface 23.

[0035] Each plate 4 comprises a main portion 40 mounted in the cell 20 extending in the longitudinal direction x' between a first longitudinal end 402 and an opposite second longitudinal end 403. The plate 4 is further shown in a three-dimensional view in FIG. 4. The first and second longitudinal ends 402 and 403 are located respectively in the same radial plane as the first and second axial edges 202, 203.

[0036] Each main portion 40 comprises in this case a maximum width L1 measured perpendicular to the longitudinal direction x'. In this case the main portion 40 has a plate shape having a constant width, i.e. the maximum width L1 measured perpendicular to the longitudinal direction x' and to the radial direction over the entire length and a thickness e4 visible in FIG. 4, measured radially, constant. This maximum width L1 is in this case at least two times smaller than a width L2 of the cell 20 measured in the same direction in the same plane. This makes it possible to form, when the main portion 40 is located radially between the bottom of the cell 20 and a blade root 32 inserted in the cell, two channels on each side extending along the main portion 40 can be formed. Each channel can thus make it possible to cool the blade root, for example by being connected to a fresh air duct not shown.

[0037] The plate 4 further comprises a first longitudinal end portion 42 extending from the first longitudinal end 402 of the main portion 40. The first longitudinal end portion 42 comprises at least one first anti-rotation part 421 abutting against the second radial surface 22 of the disc 2 between the bottom of the cell and the axis X.

[0038] The first anti-rotation part 421 comprises an axial stop surface 422 in contact against the second radial surface 22 of the disc 2, in this case a downstream radial surface, visible in FIG. 3B. The blade root 32 comprises on the upstream side a platform 31

[0039] The plate 4 further comprises a second longitudinal end portion 43 extending from the second longitudinal end 403 of the main portion 40. The second longitudinal end portion 43 comprises at least one second anti-rotation part 431 in abutment against a radial surface 324 of the blade root 32, in this case a downstream radial surface on the side of the first radial surface 23 of the disc 2. This anti-rotation part 431 therefore comprises an axial abutment surface 432 in contact against the radial surface 324 of the blade root 32. The second anti-rotation part 431 extends radially from the second longitudinal end 403 towards the outside (relative to the axis X), i.e. opposite the first anti-rotation part 421 which extends from the first longitudinal end 402 radially towards the inside (towards the axis X).

[0040] At least one of the two anti-rotation portions 421, 431 comprises a width L42, L43 greater than the maximum width L1 of the main portion. In this example, the two longitudinal end portions 42, 43 each have their anti-rotation portion 421, 431 wider than the maximum width L1 of the main portion. The widths L42, L43 of each of the two anti-rotation portions 421, 431 are measured perpendicular to the radial and axial direction.

[0041] The anti-rotation parts 421, 431 are oriented circumferentially towards each other such that they are crossed by a plane (P(d,x)) comprising the straight line d and the axis X of rotation, shown in figure 5B representing a schematic diagram of an axial view of the plate 4 of the assembly of figure 5A. Figure 5A represents a schematic diagram of a top view of the insert 4 in a cell 20 without a blade root 32, in which the straight line d passes above the anti-rotation part 421 of the first longitudinal end portion 42 and above or even below, depending on the radial distance from the axis X of the straight line d, the anti-rotation part 431 of the second longitudinal end portion 43. The insert 4 shown in this figure 5A is immobilized in rotation by its anti-rotation parts 421, 431 bearing against the disc and the tooth, unlike the insert of the prior art explained in relation to figure 2B.

[0042] In this example, the straight line d passes through the middle of a width of the alveolus 20 measured perpendicular to the axis X and in the middle between the first radial face 22 and the second radial face 23 of the disc 2, but could be shifted towards one of the two teeth (while remaining parallel to the axis of rotation X). In the case where the straight line d is offset towards one of the teeth, one of the two anti-rotation parts 421, 431 advantageously comprises a width greater than the other anti-rotation part 431, 421.

[0043] Advantageously, the two anti-rotation parts 421, 431 comprise a lateral edge which is flush with the plane (P(d,x)). This makes it possible to avoid an excess of non-useful material.

[0044] In this example, shown in Figure 4, the two longitudinal end portions 42, 43 are of identical shape but could each have a different shape from one another. The longitudinal end portions 42, 43 are also furthermore of identical dimension. Thus the same machine tool can form the two longitudinal end portions 42, 43 without changing the setting or program.

[0045] In this example, the first longitudinal end portion 42 and the second longitudinal end portion 43 respectively comprise a first and a second intermediate portion 423, 433 extending from the corresponding first and second anti-rotation part 421, 431 and respectively a first fold 420 and a second fold 430 each extending from the main portion 40 to the first and a second intermediate portion 423, 433. More precisely, the first fold 420 extends from the first longitudinal end 402. Furthermore, the second fold 430 extends from the second longitudinal end 403 of the main portion 40.

[0046] The first and second folds 420, 430 are each curved to form a spring effect to each apply a force respectively to the first anti-rotation part 421, 431 against respectively the disc 2 and the blade root 32.

[0047] In this example, the first and second folds 420, 430 as well as the first and a second intermediate portion 420, 430 each have a width constant to the width L1 of the main portion 40. A fold is formed between each intermediate portion 420, 430 and each anti-rotation part 421, 421 of each longitudinal end portion 42, 43.

[0048] The first and second longitudinal end portions 42, 43 shown in FIG. 5A have the same thickness e4 as that of the main portion 40. In particular, the plate 4 is formed from a cut and folded sheet metal forming the two different longitudinal end portions 42, 43 from the main portion 40.

[0049] Preferably, the rotor assembly comprises a flange (not shown) mounted on the side of the first radial face 22 of the disc 2 to retain the blade root 32 in the other direction of the axial direction of insertion.

[0050] In particular, the rotor assembly may comprise one or more fresh air circuits each opening onto each cell 20 and an intercalated-tooth-cell duct formed by the space located between each tooth 21 forming the cell 20 and the main portion 51 of each wedge 5. The flange may further form against the disc a part of a cooling channel and form an outlet or an inlet for fresh air in the cell 20 by circulating in the intercalated-tooth-cell duct.

[0051] For example, the assembly is a turbomachine rotor, for example a rotor of a low-pressure turbine extending around a longitudinal axis, conventionally comprising one or more rotor disks 2 carrying on their outer periphery a plurality of moving blades 3. The moving blades 3 each have a radially internal part, or blade root, extended by a blade 30. These moving blades 3 are housed at their root 32 in the cells 20 which open onto the outer peripheral surface of the rotor disk.

[0052] The positioning of the blade roots 32 in the cells 20 of the rotor discs 2 is done by translation in a longitudinal insertion direction x' inclined relative to the axis x of the turbomachine. Each stage of the rotor can thus comprise the rotor assembly.

[0053] Thus the assembly can comprise moving blades 3 each comprising a blade root 32 housed in a corresponding cell 20 forming a turbine rotor stage of a turbomachine, for example a low pressure turbine or a fan rotor.

[0054] Each main portion 51 is thus located between the bottom of the corresponding cell 20 and the corresponding blade root 32, and each axially retaining longitudinal end portion 53 is pressed against a radial surface of the corresponding blade root 32.

[0055] Figure 6 represents a three-dimensional view of a plate 4 of an assembly according to another exemplary embodiment. The plate 4 is identical to that of the first exemplary embodiment except that the first and second longitudinal end portions 42, 43 are different from each other and that each intermediate portion 430, 420 between the anti-rotation part 421, 431 and the corresponding first fold 420, 430, extends by increasing its width until obtaining the maximum width L42, L43 of the anti-rotation part 431, 422. In this example, the radial length of each of the first longitudinal end portions 42, 43, are different, in particular the first longitudinal end portion 42 is less long radially (i.e. the height) than the second longitudinal end portion 43 because the “height” of the anti-rotation part 421 is constrained by the integration of an axial stop flange at the level of the disc. It is therefore not possible to lengthen it in height. Furthermore, the anti-rotation portion 431 comprises a lateral edge on the side of the protrusion relative to the elbow 430 having a bevel so as not to exceed the bulb-shaped radial surface 324 of the blade root 32.

[0056] The invention also relates to a turbomachine comprising such a rotor assembly of a turbomachine.

[0057] Unless otherwise specified, the same element appearing in different figures has a single reference.

Claims

CLAIMS

1. A turbomachine rotor assembly, comprising: - a disc (2) with an axis of rotation (x), comprising: o a first and a second radial surface (23, 22) axially opposite relative to the disc (2), o teeth (21) at the radially external periphery of the disc (2), connecting the first radial surface (23) to the second radial surface (22) and o cells (20) each delimited by two circumferentially adjacent teeth (21), each cell (20) extending from a first axial end edge (202) which connects the cell (20) to the first radial surface (23) to a second axial end edge (203) which connects the cell (20) to the second radial surface (23), each cell (20) comprising a longitudinal direction (x') for the insertion of a blade root (32), which is preferably inclined relative to the axis of rotation (x), - a plate (4) intended to hold in a single axial direction a blade (3) in one of the cells (20), comprising: o a main portion (40) mounted in the cell (20), the main portion (40) extending in the longitudinal direction (x') between a first longitudinal end (402) and a second opposite longitudinal end (403), comprising a width (L1) measured perpendicular to the longitudinal direction (x') and the radial direction, o a first longitudinal end portion (42) and a second longitudinal end portion (43) extending axially on either side of the main portion (40), the first longitudinal end portion (42) and the second longitudinal end portion (43) each comprising an anti-rotation part (421, 431), the anti-rotation part (421) of the first longitudinal end portion (42) cooperating with there second radial surface (22) of the disc (2), the anti-rotation part (421) extending from the first longitudinal end portion (42) cooperates with the second radial surface of the disc located radially between a bottom of the cell and the axis of rotation and the anti-rotation part (431) of the second longitudinal end portion (43) being intended to cooperate with a root of a blade (32), characterized in that at least one anti-rotation part (421, 431) has a width (L41, L42) taken perpendicular to the radial and axial direction, wider than the width (L1) taken perpendicular to the radial and axial direction, of the main portion (40).

2. A turbomachine rotor assembly according to the preceding claim, wherein the first radial surface (23) of the disc (2) is an upstream radial surface and wherein the second radial surface (22) of the disc (2) is a downstream radial surface.

3. A turbomachine rotor assembly according to claim 1 or 2, wherein the width (L41, L42) taken perpendicular to the radial and axial direction, of each of the two anti-rotation parts (421, 431) extends in a plane normal to the axis of rotation

4. A turbomachine rotor assembly according to any preceding claim, wherein the first longitudinal end portion (42) and the second longitudinal end portion (43) of the plate (4) are of identical shape.

5. A turbomachine rotor assembly according to the preceding claim, wherein the first longitudinal end portion (42) and the second longitudinal end portion (43) are of the same dimension.

6. Turbomachine rotor assembly according to one of the preceding claims, in which the maximum width (L1) of the main portion (40) taken perpendicular to the radial and axial direction, is at less than twice smaller than the width (L2) of the cell (20), taken perpendicular to the radial and longitudinal direction.

7. A turbomachine rotor assembly according to any preceding claim, wherein: - the first longitudinal end portion (42) comprises a first elbow (420) extending from the main portion (40) to the anti-rotation part (421) of the first longitudinal end portion (42), - the second longitudinal end portion (43) comprises a second elbow (430) extending from the main portion (40) to the anti-rotation part (431) of the second longitudinal end portion (43), - in which the first elbow and second elbow (420, 430) each have a maximum width taken perpendicular to the radial and axial direction, less than respectively the maximum width (L42, L43) taken perpendicular to the radial and axial direction, of the corresponding anti-rotation part (421, 431).

8. A turbomachine rotor assembly according to any preceding claim, wherein the first and second longitudinal end portions (42, 43) respectively comprise a first and second intermediate portion (423, 433) each extending between the corresponding elbow (420, 430) and the anti-rotation portion (421, 431), the first and second intermediate portions (423, 433) each having a width taken perpendicular to the radial and axial direction which widens increasingly from the elbow (420, 430) corresponding to the anti-rotation portion (421, 431).

9. A turbomachine rotor assembly according to any preceding claim, wherein each of the anti-rotation portions (421, 431) has a width taken perpendicular to the radial and longitudinal direction of the main portion, greater than the width (L1) taken perpendicular to the radial and longitudinal direction of the main portion (40).

10. A turbomachine rotor assembly according to any preceding claim, wherein the wafer (4) is formed from of a sheet metal cut and folded to form the first and second longitudinal end portions (42, 43) from the main portion (40).

11. A turbomachine rotor assembly according to any one of the preceding claims, further comprising blades each comprising a blade root (30) housed in a corresponding cell (20) which opens at the radially outer periphery of the disc (2), each plate (4) comprising: - the main portion (40) between the bottom of the corresponding cell (20) and the corresponding blade root (30), - the anti-rotation part (431) which cooperates with a radial surface of the blade root (32).

12. A turbomachine rotor assembly, according to any one of the preceding claims, comprising an air circuit opening into at least one cell (20)

13. A turbomachine comprising a rotor assembly of a turbomachine, according to any one of the preceding claims.

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