MOBILE WHEEL FOR AN AIRCRAFT TURBOMACHINE

Abstract

The invention relates to a mobile wheel for a turbomachine comprising an annular disc comprising alternating teeth and grooves, and mobile blades mounted on the periphery of the disc, each root of a blade comprising a bulb (26) intended to be housed in a groove (32) of the disc and two walls (29) arranged on either side of the bulb and intended to bear against the bearing walls (36) of two adjacent teeth, characterized in that: each bearing wall of a tooth of the disc comprises a protuberance (70) rising radially outwards and extending from the top of the tooth in the direction of a groove (32), and each wall of a blade comprises a shoulder (100) intended to bear against the protuberance (70) of the bearing wall (36) of the tooth arranged opposite the wall. Figure for abstract: Figure 7

Description

Title of the invention: MOVING WHEEL FOR AN AIRCRAFT TURBOMACHINE Technical field

[0001] The present invention relates in particular to a mobile wheel for an aircraft turbomachine. Prior art

[0002] Turbomachines generally comprise moving blades which equip moving fan wheels, compressor wheels or even moving turbine wheels.

[0003] [Fig. 1] illustrates such a turbomachine wheel 10 equipped with moving blades. A blade 20 of a turbomachine wheel, and in particular of a turbomachine turbine or compressor wheel, generally comprises a root 22 and an aerodynamic blade 24 extending radially outwards along a stacking axis from the root 2.

[0004] The roots 22 of the moving blades are intended to be inserted into an annular disc 30 of the wheel 10. In particular, the roots 22 of the moving blades are then received in grooves 32, also called cells, formed at the external periphery of the turbomachine wheel. The grooves 32 are distributed regularly around the axis of rotation of the turbomachine wheel. Two adjacent grooves are separated by a tooth 34 of disc 30.

[0005] More precisely, a foot 22 of a blade 20 comprises a bulb 26 and a stilt 27 extending radially from the bulb 26. The bulb 26 is connected to the stilt 27 by a neck 28. The latter corresponds to a portion of the bulb 26 which comprises a small section or a reduced thickness compared to the rest of the bulb 26. In general, the grooves 32 are each intended to receive a bulb 26 and have a shape complementary to that of the bulb of the foot of the blade. The bulbs of the blade feet may have a dovetail or fir tree shape.

[0006] Each movable blade root 22 further comprises at least two walls 29 arranged on either side of the bulb 26 and each intended to bear against bearing walls 36 of two adjacent teeth 34. Each tooth 34 comprises a top S and two bearing walls 36 connected by the top S.

[0007] In operation, that is to say when the turbomachine moving wheel is rotating around its axis of rotation, dislocations between two adjacent moving blades have been observed as illustrated in [Fig. 2] at their roots. By definition, the dislocation is the maximum possible separation in a transverse plane between two adjacent moving blades mounted in their disc. By "transverse plane" we mean a plane perpendicular to a radial direction. However, a dislocation in a fleet can lead to a request for engine removal.

[0008] Consequently, it is necessary to limit the value of this as much as possible in order to avoid these fleet detachments.

[0009] The invention aims to remedy the aforementioned drawbacks. Summary of the invention

[0010] Thus, an objective of the present invention is to propose an optimal solution making it possible to limit the value of dislocation between two adjacent blades of a turbomachine moving wheel.

[0011] To this end, the invention relates to a mobile wheel for a turbomachine, in particular of an aircraft, comprising:

[0012] - an annular disc comprising teeth and grooves distributed regularly around the periphery of the disc, two adjacent teeth being separated by a groove, each tooth comprising a top and two support walls connected by the top, and - moving blades mounted on the periphery of the disc, each moving blade comprises a root and a blade extending from the root and a platform separating the blade from the root, each root comprising a bulb intended to be housed in a groove of the disc and two walls arranged on either side of the bulb and intended to bear against the bearing walls of two adjacent teeth,

[0013] characterized in that:

[0014] - each bearing wall of a tooth of the disc comprises a protuberance rising radially outwards and extending from the top of the tooth towards a groove, and - each wall of a moving blade has a shoulder intended to bear against the protuberance of the support wall of the tooth arranged opposite the wall.

[0015] The invention thus makes it possible to achieve the aforementioned objective. In particular, the invention proposes modifying the design of the walls of the moving blades and that of the teeth of the wheel disc in order to limit the dislocations between the moving blades.

[0016] The invention makes it possible to increase the distance between the top of the teeth of the disc and the point of contact between the bulb and the cell. The inventors have found that increasing this distance makes it possible to reduce the maximum possible spacing between two successive blades and therefore to limit the risk of disengagement between two successive blades in a fleet.

[0017] The mobile wheel for a turbomachine according to the invention may comprise one or several of the following characteristics, taken in isolation from each other or in combination with each other:

[0018] - the thickness of the protuberance of a support wall of a disc tooth is greater than the thickness of the shoulder of a low wall; - the protuberance of the disc tooth has a first rectilinear part in a first direction and a second curved part, the first rectilinear part being arranged between the second curved part and the top of the tooth, the shoulder of the wall has a first curved part and a second rectilinear part, the first curved part being arranged between the second rectilinear part and the bulb of the foot, the second rectilinear part being substantially parallel to the first rectilinear part of the protuberance of the tooth, and the second curved part of the protuberance of the tooth is spaced from the first curved part of the shoulder of the wall in the first direction; - the root of the moving blade and the groove of the disc receiving the root of the moving blade have symmetry with respect to a radial plane, the center of curvature of the first curved part of the shoulder of the wall is at a first distance from the radial plane, and the center of curvature of the second curved part of the protuberance of the tooth is at a second distance from the radial plane greater than the first distance; - the second curved part of the tooth protrusion has a convex shape; - the first curved part of the shoulder of the wall has a concave shape; - the turbomachine comprises a turbine having at least five stages and the moving wheel is a wheel of a stage of the turbine greater than or equal to the fifth stage, preferably the fifth stage; - the thickness of the shoulder of the wall is between 0.17 mm and 0.23 mm, and preferably equal to 0.2 mm, and the thickness of the protuberance of a support wall of a disc tooth is between 0.2 mm and 0.4 mm, preferably equal to 0.3 mm; - the radius of curvature of the first curved part of the shoulder of the wall is between 0.77 mm and 0.83 mm, and preferably equal to 0.8 mm; - the first distance D2 between the center of curvature of the first curved part of the shoulder of the wall and the radial plane P is between 4.9 mm and 5.05 mm, preferably equal to 5 mm; - the wall comprises a rectilinear part arranged between the shoulder and the bulb and extending substantially parallel to the second rectilinear part of the shoulder of the wall; - the rectilinear part of the wall arranged between the shoulder and the bulb extends over a distance along the first direction of between 0.9 mm and 3.9 mm; - physical characteristics relating to the disc tooth protrusion and the blade wall shoulder are determined by computer-aided design optimization, including the thickness of the wall shoulder, the thickness of the protrusion, the radius of curvature of the first curved portion of the wall shoulder, and the distance between the center of curvature of the first curved portion of the wall shoulder and a radial plane of symmetry of the blade root.

[0019] The invention also relates to a turbine for a turbomachine, in particular for an aircraft comprising at least one moving wheel according to the invention and as described above. Preferably, the turbine is a low-pressure turbine. Preferably, the turbine has between five and seven stages. The moving wheel according to the invention is preferably a wheel of a stage of the turbine greater than or equal to the fifth stage, and preferably the fifth stage.

[0020] The invention also relates to a turbomachine, in particular for an aircraft, comprising at least one mobile wheel according to the invention and as described above or a turbine according to the invention and as described above. Brief description of the drawings

[0021] The present invention will be better understood and other details, characteristics and advantages of the present invention will appear more clearly on reading the description of a non-limiting example which follows, with reference to the appended drawings in which:

[0022] - [Fig. 1], already described, schematically represents a front and partial view of an example of a turbomachine mobile wheel comprising a cell in which a foot according to the prior art is received; - [Fig.2], already described, illustrates an enlarged view of a turbomachine moving wheel having a gap between two adjacent moving blades; - [Fig.3] illustrates in axial section a turbomachine to which the invention applies; - [Fig.4] is a perspective and partial view of an example of a moving wheel which comprises a disc equipped with vanes extending from the periphery of the disc; - [Fig.5] is a front view of an example of a turbomachine disk according to the invention intended to be equipped with moving blades; - [Fig.6] is a perspective and partial view of the turbomachine disk of [Fig.5]; - [Fig.7] is a front view of an example of a foot of a blade according to the invention; and - [Fig.8] is a perspective and partial view of the blade root of [Fig.7].

[0023] The elements having the same functions in the different implementations have the same references in the figures. Description of the embodiments

[0024] [Fig. 3] shows an axial and partial sectional view of a turbomachine with longitudinal axis X, in particular a dual-flow turbomachine 50 to which the invention applies. Of course, the invention is not limited to this type of turbomachine.

[0025] Such a double-flow turbomachine 50 generally comprises a gas generator 51 upstream of which a fan 52 is mounted. In the present invention, and generally, the terms “upstream” and “downstream” are defined in relation to the circulation of fluids in the turbomachine, and here along the longitudinal axis X.

[0026] The turbomachine 50 comprises a primary vein 53 in which a primary aerodynamic flow “P” or hot flow circulates and a secondary vein 54 in which a secondary aerodynamic flow “S” or cold flow circulates around the primary vein 53. The primary and secondary veins 53, 54 are coaxial.

[0027] The gas generator 51 comprises a set of gas compressors 55 (which may comprise a low pressure (LP) compressor 56 and a high pressure (HP) compressor 57), a combustion chamber 58 and a set of turbines 59 (which may comprise a high pressure turbine 60 and a low pressure turbine 61). The latter are traversed by the primary flow P. In particular, the primary vein 53 is delimited radially by an annular internal casing 62 and an annular inter-vein casing 63. The inter-vein casing 63 envelops the gas generator 51.

[0028] The terms "internal", "external", "radial" and "radially" are defined with respect to a radial axis Z perpendicular to the longitudinal axis X around which the turbomachine extends. Thus, by "lower", "inner" or "inner", we will designate any positioning close to the longitudinal axis X in the radial direction while by "upper", "outer" or "outer", we will designate any positioning further from the longitudinal axis X in the radial direction than the lower, inner or inner positioning.

[0029] As for the secondary vein 54, this is delimited radially by the inter-vein casing 63 and an annular external casing 64 to which a fan casing 65 is secured. The secondary flow S circulates around the inter-vein casing 59.

[0030] The turbomachine 50 further comprises an ejection nozzle 66, located downstream of the gas generator 51 through which the primary flow P and the secondary flow S are ejected outside the turbomachine, and in particular into the atmosphere, to produce a propulsive force, the secondary flow "S" here providing the majority of the thrust.

[0031] Each turbine (like each compressor) comprises one or more stages. In the case of a multi-stage turbine, these are arranged successively along the longitudinal axis X. Each turbine stage comprises a bladed wheel forming a rotor and a fixed wheel forming a stator. The blades of this stator are designated by the term distributor blade. Each bladed wheel is arranged downstream of a distributor wheel. A distributor diverts and accelerates the gas flow from the combustion chamber towards the turbine blades at an appropriate angle and speed in order to rotate these blades and the turbine disk.

[0032] [Fig.4] illustrates an example of a wheel, in particular a moving wheel of a turbine low pressure. This wheel comprises elements common to the wheel of the prior art described in relation to [Fig.l] and which are designated by the same numerical references. Each movable wheel 10 comprises an annular disc 30 centered on the longitudinal axis X. A plurality of movable blades 20 are mounted on the periphery of the disc 30 and are distributed circumferentially regularly, around the disc 30 of the movable wheel 10.

[0033] Figures 5 and 6 show an example of a turbomachine movable wheel disc 30 according to the invention intended to be equipped with movable blades, while Figures 6 and 7 illustrate an example of such turbomachine movable wheel blades according to the invention. The disc and the blades comprise elements common to the disc and the blade of the prior art described in relation to [Fig. 1] and which are designated by the same numerical references.

[0034] With reference to Figures 5 and 6, the annular disc 30 of the movable wheel 10 comprises several grooves 32 or cells arranged at the external periphery of the disc and several teeth 34. The grooves 32 and the teeth 34 are distributed regularly around the axis of rotation of the wheel of the turbomachine. The disc 30 has as many grooves 32 as teeth 34, the grooves 32 and the teeth 34 being alternated. In other words, two adjacent grooves 32 are separated by a tooth 34 and two adjacent teeth 34 are separated by a groove 32. Each groove 32 is intended to receive at least partially a root 22 of a blade 20 and the root 22 of the blade rests at least partially on the two teeth 34 of the disc adjacent to the groove 32 receiving the root 22 of the blade. For this purpose, each tooth 34 generally comprises a top S and two support walls 36A, 36B connected by the top S.The two support walls 36A, 36B of the same tooth 34 are flat and inclined relative to each other, that is to say they form an acute angle with apex S.

[0035] Preferably, the two support walls 36A, 36B are symmetrical with respect to a radial plane PI passing through the apex S of the tooth 34. One of the support walls 36A extends in particular in a first direction Y1 and to the longitudinal axis X. The other of the support walls 36B of the same tooth 34 extends in a second direction Y2 symmetrical to the first direction Y1 with respect to the plane PL. The two support walls 36A, 36B also extend in a direction parallel to the longitudinal axis X.

[0036] According to the invention, each support wall 36A, 36B further comprises a protuberance 70 or elevation rising radially outwards and extending from the apex S of the tooth 34 in the direction of the groove 32 juxtaposed with the tooth. In particular, for each bearing wall, the protrusion 70 of the disc tooth has a first rectilinear part 72 and a second curved part 74. The first rectilinear part 72 is arranged between the second curved part 74 and the apex S of the tooth 34. Furthermore, the first rectilinear part 72 forms a plateau which extends along a plane parallel to the bearing wall 36. Thus, in the case of the bearing wall 36A extending along the first direction Y1 and the longitudinal axis X, the protrusion 70A of this bearing wall extends along the first direction Y1 (and the longitudinal direction X).Similarly, the protrusion 70B of the support wall 36B extending in the second direction Y2, also extends in this second direction Y2 (and the longitudinal direction X). The thickness “El” of the protrusion 70 of a support wall 36 of a tooth 34 of disc 30 is defined as the distance separating the plate (the first rectilinear part 72) from the protrusion of the associated support wall 36.

[0037] Preferably, the second curved portion 74 has a convex shape having a center of curvature and a radius of curvature, respectively denoted "Cl" and "RI". The center of curvature Cl of the second curved portion is arranged at a distance, denoted "DI", from the plane PL. By distance between a point and an axis or plane, we mean the distance orthogonal to this axis or plane, that is to say the smallest distance between the point and this axis or plane.

[0038] In Figures 7 and 8 is illustrated an example of a blade 20 of a mobile wheel 10 of a turbomachine according to the invention. Each blade 20 comprises a root 22 and an aerodynamic blade 24 extending from the root 22 along a stacking axis. This stacking axis is substantially parallel to the radial axis Z. The blade 24 comprises a leading edge 80 and a trailing edge 81 (visible in [Fig. 4]) which are opposite, here along the longitudinal axis X. Each blade 24 is arranged in the aerodynamic flow so that the leading edge 80 is placed upstream of the trailing edge 81. The leading edge 80 and the trailing edge 81 are connected by a pressure surface 82 and an extrados surface which are opposite along a transverse axis T as shown in [Fig. 4]. The transverse axis T is perpendicular to the longitudinal axis X, as well as to the radial axis Z.

[0039] As illustrated in [Fig.4], each foot 22 comprises a bulb 26 intended to be housed in a groove 32 of corresponding shape in the disc 30. Preferably, the foot of the moving blade, and in particular the bulb 26, and the groove 32 of the disc receiving it have a symmetry with respect to a radial plane P2.

[0040] The bulb 26 is located at a proximal end of the blade. The root 2 also comprises a stilt 27 which extends radially from the bulb 26. In particular, Péchasse 27 is connected to the bulb 26 via a neck 28. Furthermore, Péchasse 27 is connected to a platform 83 which separates the blade 24 from the root 22 of the blade 20. The platform 83 is intended to form at least a portion of a radially internal wall of a vein of the turbomachine. In other words, Péchasse 27 extends radially between the platform 83 and the bulb 26.

[0041] With reference to Figures 4, 7 and 8, the bulb 26 extends along the longitudinal axis X between an upstream end face 84 and a downstream end face 85. Each upstream and downstream end face 84, 85 is defined respectively in a plane which is perpendicular to the longitudinal axis X. The bulb 26 also extends transversely between a first lateral surface 86 and a second lateral surface 87 (see [Fig.5]). More precisely, the bulb 26 is formed of a base 88 widened along the transverse axis with a radially internal face 89 which is defined in a plane perpendicular to the radial axis Z. The radially internal face 89 is located at the proximal end of the blade. The neck 28 is located radially above the widened base 89. In other words, the neck is located between Péchasse 27 and the widened base 89. The first lateral surface 86a and the second lateral surface 87a at the neck 28 are substantially rectilinear in this example.These can of course have a curvature and be substantially convex. The stilt 27 comprises a radial wall 90 or core which extends radially between the bulb 26 and the platform 83. This also extends along the longitudinal axis between an upstream wall 91 and a downstream wall 92 (in a situation of installation in the turbomachine and along the longitudinal axis). Each upstream wall 91 and downstream wall 92 extends along the transverse axis T. The upstream and downstream walls 91, 92 are connected on the one hand, at their radially external ends to the platform 83 and on the other hand, at their radially internal ends to the neck 28 (at a connection zone). For this, the upstream wall 91 and the downstream wall 92 each comprise a first lateral face 93 and a second lateral face 93 between which they extend. The first lateral face 93 and the second lateral face 94 are opposite with respect to the transverse axis T.The term "lateral" is defined relative to the transverse axis T. .

[0042] With reference to [Fig.7], each first lateral face 93 and second lateral face 94 of the upstream and downstream walls 91, 92 are connected to the neck 28. In particular, each first lateral face 93 and second lateral face 94 are respectively connected to the first lateral surface 86a and to the second lateral surface 87a via a connecting surface 95. The connecting surface 95 has a first part rectilinear 96 and a second curved part 97. The second part 97 forms a connecting radius with the neck 28 (and in particular with the first and second lateral surfaces 86a, 87a). The rectilinear part 96 of the connecting surface 95 forms the walls 29 of the root and is intended to rest on the bearing walls 36 of two adjacent teeth 34 when the wheel disc 30 of the wheel 10 is equipped with the movable blade. In other words, the root 22 comprises walls 29 arranged on either side of the bulb 26 and are configured to bear against the bearing walls 36 of two adjacent teeth when the wheel disc is equipped with the movable blade. For this purpose, the walls 29 have flat surfaces inclined relative to each other. Preferably, the walls 29 are symmetrical with respect to the radial plane P2 of symmetry of the blade root and in particular of the bulb.The flat surfaces of the walls are substantially parallel to the support walls 36 on which they respectively rest when the wheel is assembled. Thus, one of the walls 29A extends substantially along the first direction Y1 of extension of the support wall 36A of the tooth on which the wall rests. Respectively, the other wall 29B extends substantially along the second direction Y2 of extension of the support wall 36B of the neighboring tooth on which the other wall rests.

[0043] According to the invention, each wall 29 comprises a shoulder 100 intended to bear against the protuberance 70 of the bearing wall 36 of the tooth 34 arranged opposite the wall 29. The shoulder 100 rises radially outwards. In particular, for each wall, the shoulder 100 has a first curved portion 101 and a second rectilinear portion 102. The first curved portion 101 is arranged between the second rectilinear portion 102 and the bulb 26 of the foot. The second rectilinear portion (102) is substantially parallel to the first rectilinear portion (72) of the protuberance (70) of the tooth. In other words, it extends in a plane parallel to the first direction Y1 (or second direction Y2) and the longitudinal direction X.

[0044] Each wall 29 comprises another rectilinear part 103 arranged between the shoulder 100 and the bulb 26 and extending substantially parallel to the support wall 36 of the tooth on which the wall rests. The thickness “E2” of the shoulder 100 of the blade root is defined as the distance separating the second rectilinear part 102 of the shoulder and the other rectilinear part 103.

[0045] Advantageously, the thickness E1 of the protuberance 70 of a support wall 36 of a disc tooth is greater than the thickness E2 of the shoulder 100 of a wall 29. Thus, the blade roots rest mainly on the protuberances of the disc teeth.

[0046] Preferably, the first curved portion 101 of the shoulder 100 of the wall has a concave shape having a center of curvature and a radius of curvature, respectively denoted “C2” and “R2”. The center of curvature C2 of the first portion curved 101 is arranged at a distance, denoted “D2”, from the plane P2. Advantageously, the second curved portion 74 of the protuberance 70 of the tooth is spaced from the first curved portion 101 of the shoulder 100 of the wall in the first direction. In other words, the center of curvature C1 of the second curved portion 74 of the protuberance 70 of the tooth is at a second distance D3 from the radial plane P2 greater than the distance D2 between the center of curvature C2 of the first curved portion 101 of the shoulder 100 of the wall and the plane P2. This means that the center of curvature C1 of the protuberance 70 of the tooth is further from the plane P2 than the center of curvature C2 of the shoulder 100 of the foot wall.

[0047] The physical characteristics relating to the protuberance of the disc tooth and the shoulder of the blade wall are advantageously determined by computer-aided design optimization, in particular:

[0048] - the thickness E2 of the shoulder 100 of the wall, - the thickness El of the protuberance 70, - the radius of curvature C2 of the first curved part 101 of the shoulder 100 of the wall, and - the distance D2 between the center of curvature C2 of the first curved part 101 of the shoulder 100 of the wall and the radial plane P2 of symmetry of the foot 22 of the blade.

[0049] Such optimizations take into account the maximum and minimum manufacturing tolerances of the blade roots and the teeth and grooves of the movable wheel disc.

[0050] These optimizations thus make it possible to determine these physical characteristics making it possible to limit the dislocation between two consecutive moving blades mounted on a disk and to calculate this.

[0051] The invention applies in particular to the moving wheels of low pressure turbines of a turbomachine and in particular to the moving wheels of stages five to seven of such turbines.

[0052] For example, for the fifth-stage moving wheel of a low-pressure turbine, the maximum value of dislocation with a design according to the prior art is 5.6 mm. This is quite significant and explains the cases of dislocation observed in the fleet.

[0053] The optimization calculations resulted in the following physical characteristics:

[0054] - the thickness E2 of the shoulder 100 of the wall is between 0.17 mm and 0.23 mm, and preferably equal to 0.2 mm; - the thickness El of the protuberance 70 of a support wall 36 of a disc tooth is between 0.2 and 0.4 mm, preferably equal to 0.3 mm; - the radius of curvature C2 of the first curved part 101 of the shoulder 100 of the wall 29 is between 0.77 mm and 0.83 mm, and preferably equal to 0.8 mm; the first distance D2 between the center of curvature C2 of the first curved part 101 of the shoulder 100 of the wall and the radial plane P2 is between 4.9 mm and 5.05 mm, preferably equal to 5 mm; the rectilinear part 103 of the wall 29 arranged between the shoulder 100 and the bulb 26 extends over a distance along the first direction of between 0.9 mm and 3.9 mm;

[0055] A design according to the invention and in particular with the preferred values ​​above makes it possible to greatly reduce the dislocation value from 5.6 mm to 1.7 mm, i.e. a reduction of approximately 4 mm. The dislocation value is thus reduced by 70%.

[0056] Such a mobile wheel design makes it possible to reduce the (orthogonal) distance between the top of the disc teeth and the point of contact between the bulb and the socket marked D in [Fig.l].

[0057] Furthermore, these geometric changes are minor in the sense that they do not call into question the mechanical dimensioning because these are areas subject to little mechanical stress, the mass impact is low in particular and without the need for significant updating of the certification file of the turbomachine.

[0058] These geometric modifications can be advantageously achieved by simple additional machining of the blade root walls and by broaching the disc.

Claims

1.

2.

3. Claims Mobile wheel (10) for a turbomachine (50), in particular of an aircraft, comprising: - an annular disc (30) comprising teeth (34) and grooves (32) distributed regularly around the periphery of the disc, two adjacent teeth being separated by a groove, each tooth comprising a top (S) and two support walls (36) connected by the top, and - movable blades (20) mounted on the periphery of the disc, each movable blade comprises a root (22) and a blade (24) extending from the root and a platform separating the blade from the root, each root comprising a bulb (26) intended to be housed in a groove (32) of the disc (30) and two walls (29) arranged on either side of the bulb and intended to bear against the bearing walls (36) of two adjacent teeth, characterized in that: - each support wall of a tooth of the disc comprises a protuberance (70) rising radially outwards and extending from the top (S) of the tooth (34) in the direction of a groove (32), and - each wall of a moving blade comprises a shoulder (100) intended to bear against the protuberance (70) of the support wall (36) of the tooth arranged opposite the wall. A mobile wheel according to claim 1, wherein the thickness (El) of the protuberance (70) of a support wall of a disc tooth is greater than the thickness (E2) of the shoulder (100) of a wall. A moving wheel according to claim 1 or 2, wherein: - the protuberance (70) of the disc tooth has a first rectilinear part (72) in a first direction (Yl) and a second curved part (74), the first rectilinear part being arranged between the second curved part and the top of the tooth, - the shoulder (100) of the wall (29) has a first curved part (101) and a second rectilinear part (102), the first curved part (101) being arranged between the second rectilinear part (102) and the bulb (26) of the foot, the second rectilinear part (102) being substantially parallel to the first rectilinear part (72) of the protuberance (70) of the tooth, and - the second curved part (74) of the protuberance (70) of the tooth is spaced from the first curved part (101) of the shoulder (100) of the wall (29) in the first direction.

4. A movable wheel according to claim 3, wherein the second curved portion (74) of the protrusion (70) of the tooth (34) has a convex shape.

5. A mobile wheel according to one of claims 3 to 4, wherein the first curved portion (101) of the shoulder (100) of the wall (29) has a concave shape.

6. A moving wheel according to one of the preceding claims, in which the turbomachine comprises a turbine having at least five stages and the moving wheel is a wheel of a stage of the turbine greater than or equal to the fifth stage, preferably the fifth stage.

7. A mobile wheel according to claim 6, wherein the thickness (E2) of the shoulder (100) of the wall (29) is between 0.17 mm and 0.23 mm, and preferably equal to 0.2 mm, and the thickness (El) of the protuberance (70) of a support wall (36) of a tooth (34) of the disc (30) is between 0.2 mm and 0.4 mm, preferably equal to 0.3 mm.

8. A movable wheel according to claim 6 or 7 in combination with claim 3, wherein the radius of curvature (C2) of the first curved portion (101) of the shoulder (100) of the wall is between 0.77 mm and 0.83 mm, and preferably equal to 0.8 mm.

9. Mobile wheel according to one of claims 6 to 8 in combination with claim 4, in which the first distance (D2) between the center of curvature (C2) of the first curved part (101) of the shoulder (100) of the wall and the radial plane (P) is between 4.9 mm and 5.05 mm, preferably equal to 5 mm.

10. A mobile wheel according to one of claims 6 to 9 in combination with claim 3, wherein the wall (29) comprises a rectilinear portion (103) arranged between the shoulder (100) and the bulb (26) and extending substantially parallel to the second rectilinear portion. (102) of the shoulder (100) of the wall.

11. A movable wheel according to claim 10, wherein the straight portion (103) of the wall arranged between the shoulder and the bulb extends over a distance along the first direction of between 0.9 mm and 3.9 mm.

12. Turbine for a turbomachine, in particular of an aircraft, characterized in that it comprises at least one mobile wheel (20) according to any one of the preceding claims.

13. Aircraft turbomachine (50) characterized in that it comprises at least one mobile wheel (20) according to any one of claims 1 to 11.

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