Rotor blade for an aircraft turbine engine, and aircraft turbine engine
By repositioning the 'elephant's foot' and incorporating a triangular-shaped additional thickness, the blade design addresses stress and deformation issues, enhancing stiffness and mechanical performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2026-01-09
- Publication Date
- 2026-07-16
AI Technical Summary
Current turbomachine blade designs with 'elephant's feet' at the longitudinal ends lead to significant stress and deformation due to centrifugal forces, causing mass distribution issues and over-stressing of the outer platform.
Repositioning the 'elephant's foot' away from the lateral edges and incorporating a triangular-shaped additional thickness along the blade, which minimizes cantilevered mass and increases stiffness by redistributing the blade's mass and thickness.
This design reduces stress and deformation, enhances blade stiffness, and improves mechanical behavior by optimizing mass distribution and reducing thickness at the ends.
Smart Images
Figure FR2026050018_16072026_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE: ROTOR BLADE FOR AN AIRCRAFT TURBOMACHINE
[0003] Technical field of the invention
[0004] The present invention relates in particular to a rotor blade for an aircraft turbomachine.
[0005] Technical background
[0006] An aircraft turbomachine 10, such as that shown in Figure 1, generally comprises at least one compressor 12, 14, an annular combustion chamber 16 and at least one turbine 18, 20. The air entering the compressor 12, 14 is compressed and then mixed with fuel and burned in the combustion chamber 16. The combustion gases are then expanded in the turbine 18, 20, which causes the turbine rotor to rotate, which in turn drives the compressor rotor.
[0007] There are several turbomachine technologies, such as turboprops or turbojets, which include, for example, a propulsion propeller 22 located upstream of the turbomachine 10 and which is also driven by the turbine rotor, this propeller being able to be shrouded or unshrouded.
[0008] There are also several turbomachine configurations, such as single-spool or multi-spool. In a twin-spool turbomachine as illustrated in Figure 1, the turbomachine 10 comprises a low-pressure LP spool and a high-pressure HP spool. The low-pressure LP spool includes a low-pressure compressor rotor 12 connected by a low-pressure shaft 24 to a low-pressure turbine rotor 18. The high-pressure spool 14 includes a high-pressure compressor rotor connected by a high-pressure shaft 26 to a high-pressure turbine rotor 20. In the direction of gas flow in the turbomachine, from upstream to downstream (see arrows), the twin-spool turbomachine 10 then comprises the low-pressure compressor 12, the high-pressure compressor 14, the combustion chamber 16, the high-pressure turbine 18, and the low-pressure turbine 20.
[0009] A turbomachine compressor 12, 14 comprises one or more compression stages which extend around and along the same axis X, and which each include a rotor wheel 28 and a stator blade 30 (also called a rectifier blade - figure 2).
[0010] Similarly, a turbomachine turbine comprises one or more expansion stages which extend around and along the same axis X, and which each include a rotor wheel 28 and a stator blade 30 (also called distributor blade - figure 2).
[0011] A rotor wheel 28, for a compressor or a turbine, generally comprises a disc 32 carrying blades 34 at its periphery. The disc 32 is centered on the X axis of rotation of the wheel 28 and the blades 34 are distributed around this X axis and mounted at the periphery of the disc 32.
[0012] A rotor blade 34 comprises two platforms, an inner 36 and an outer 38, between which a blade 40 extends. The blade 40 has leading edges 42 and trailing edges 44, and lower surfaces 46 and upper surfaces 48 extending between the leading and trailing edges. The leading edge 42 is located upstream and the trailing edge 44 is located downstream with respect to the gas flow (see arrows).
[0013] The inner platform 36 is connected to a foot (not shown) which allows it to be mounted on the disk 32. The outer platform 38 is connected to at least one sealing lip 50 which projects from the outer platform 38 and is designed to cooperate by friction with an annular element 52 made of abradable material. This element 52 surrounds the rotor wheel 28 and is supported by a housing 54 which also carries the stator blade 30 located downstream of the wheel 28.
[0014] Similarly, the stator blade 30 comprises vanes 56 distributed around the X-axis. Each of these vanes 56 extends between internal 58 and external 60 platforms. The external 60 platforms of the vanes 56 are generally attached to the housing 54, and the internal 58 platforms of the vanes carry scuffs 62 that cooperate by friction with an annular element 64 made of abradable material. This element 64 is carried by the rotor, which includes the wheel 28.
[0015] Blades 34 and 56 are oriented radially with respect to the X-axis; that is, each includes an elongation axis A that extends substantially radially with respect to the X-axis. Platforms 36, 38, 58, and 60 form annular assemblies that extend around the X-axis and are generally sectored to facilitate the mounting of the wheel 28 and the blade 30. Scrapers 50 and 62 also form annular assemblies that are likewise sectored. Scrapers 50 extend radially outwards, and scrapers 62 extend radially inwards.
[0016] The cooperation of the blades 50, 62 with the elements 52, 62 allows to form seals by baffle effect and thus to limit the passage of gas in operation between the rotor and the stator, respectively at the external periphery of the wheel 28 and the internal periphery of the blade 30.
[0017] Originally, each of the elements 52, 62 has a cylindrical or stepped shape, meaning that it comprises one or more cylindrical surfaces. During a break-in phase of the turbomachine, the scrapers 50, 62 rub against the elements and form annular grooves.
[0018] It is known to incorporate raised edges or "elephant's feet" on the slats. Each slat includes a raised edge or elephant's foot which aims to define the maximum thickness of the slat and thus define the desired width of the groove to be formed by the slat.
[0019] In current techniques, to facilitate blade manufacturing, the "elephant's feet" are located at the longitudinal ends of the blades, that is, at the lateral edges of the outer platform. However, this configuration leads to drawbacks related to the distribution of the blade's mass, which generates significant stresses on the outer platform due to centrifugal force. Indeed, a substantial deformation of the blade ends is observed at the "elephant's feet," due to the fact that the cantilevered masses at the blade ends are driven by centrifugal force and subsequently over-stress the areas opposite the platform.
[0020] The invention offers a solution to this problem that is simple, effective, and economical.
[0021] Summary of the invention
[0022] The technical background includes, in particular, documents US-A1-2007 / 053778, US-A1-2010 / 290897 and JP-A-H08303204.
[0023] The invention relates to a blade for an aircraft turbomachine, this blade being intended to be mounted for rotation about an axis, extending radially with respect to this axis in a radial direction and comprising: - a blade having an aerodynamic profile delimited by a leading edge, a trailing edge, an intrados face and an extrados face which extend between the leading edge and the trailing edge,
[0024] - a foot at one radial end of the blade,
[0025] - a heel at a second radial end of the blade, opposite the first radial end, the heel comprising a platform and at least one sealing flap extending radially from the platform, each flap being delimited by an upstream face located on the leading edge side and a downstream face opposite the upstream face and located on the trailing edge side, the upstream and downstream faces being connected together by a free radial end edge of the flap, and each flap being further delimited by two opposing circumferential end edges, one circumferential end edge being located on the lower surface side and the other opposite circumferential end edge being located on the upper surface side of the blade, said at least one flap further comprising an overthickness extending axially in projection from the upstream or downstream face of the flap,the excess thickness being located at a distance from the circumferential end edges of the slat and extending along said radial direction from the platform to the free radial end edge of the slat, characterized in that the excess thickness has a triangular shape in at least one cutting plane which crosses the slat and passes through this excess thickness,
[0026] in that the excess thickness has a triangular shape in a first plane of section which passes through the excess thickness and is perpendicular to said radial direction,
[0027] and in that the excess thickness has a triangular shape in a second cutting plane which passes through the excess thickness and which is parallel to said radial direction and perpendicular to the lick.
[0028] The invention makes it possible to limit the adverse effects mentioned above. This is achieved by positioning the elephant foot away from the lateral edges of the blade. This minimizes the cantilevered mass while increasing the blade's stiffness. Furthermore, the blade's mass can be reduced by decreasing the thickness and / or width of its ends.
[0029] The geometry of the slat is further designed to increase the stiffness of the slat.
[0030] The blade according to the invention may comprise one or more of the following features, taken individually or in combination with each other:
[0031] - the first cutting plane passes through the radially external end of the lick and passes through the free edge of the radial end of the lick;
[0032] - the second cutting plane passes through a circumferential end of the excess thickness located on the side of the intrados face of the blade;
[0033] - the excess thickness has a triangular shape in a third cutting plane which passes through the excess thickness and which is parallel to said radial direction and perpendicular to the lick;
[0034] - the third cutting plane passes through a circumferential end of the excess thickness located on the side of the extrados face of the blade;
[0035] - said overthickness includes a ridge which projects outwards from the platform to the radially external end of the overthickness and which is inclined at a determined angle with respect to said radial direction;
[0036] - said ridge extends in the middle of the overthickness, in a direction parallel to this lick;
[0037] - said ridge is located at a circumferential end of the overthickness, this circumferential end being located on the side of the intrados face or the extrados face of the blade;
[0038] - said extra thickness is formed by the juxtaposition of two right prisms with triangular bases, a first right prism whose triangular bases are located respectively on the side of the intrados and extrados faces of the blade and one of whose edges is located at the junction between the platform and the blade, and a second right prism whose triangular bases are located respectively on the side of the platform and the free edge of the radial end of the blade, the first and second right prisms being joined by a junction plane which is inclined with respect to said radial direction;
[0039] - said ridge is formed by one of the edges of the second right prism;
[0040] -- said overthickness has a proper thickness measured in said direction perpendicular to said faces, which decreases progressively from the external platform to said free radial end edge and which is minimal at the level of this free radial end edge;
[0041] -- said overthickness has a proper width measured in a direction parallel to the corresponding slit, which decreases progressively from the outer platform to said free radial end edge and which is minimal at the level of this free radial end edge;
[0042] -- said overthickness has a proper thickness measured in said direction perpendicular to said faces, which decreases progressively from the crest to each of the circumferential ends of the overthickness, these circumferential ends being located respectively on the side of said circumferential end edges;
[0043] -- said overthickness has a proper thickness measured in said direction perpendicular to said faces, which decreases progressively from the crest to the circumferential end of the overthickness opposite the crest and located on the other side of said circumferential end edges; -- said overthickness is located in the middle of the corresponding slit, in a direction parallel to this slit.
[0044] The present invention also relates to a turbine for an aircraft turbomachine, comprising several blades as described above, each of which is mounted in a cavity which opens at the outer periphery of a turbine disk centered on an axis, the blades being arranged circumferentially next to each other and around an axis, the turbine further comprising an abradable annular element which surrounds the blades and in which the blade tips can cooperate by friction.
[0045] Brief description of the figures
[0046] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:
[0047] [Fig.1] Figure 1 is a schematic axial cross-sectional view of an aircraft turbomachine,
[0048] [Fig.2] Figure 2 is a semi-schematic axial cross-sectional view of a compressor or turbine stage of an aircraft turbomachine,
[0049] [Fig. 3] Figure 3 is a schematic perspective view of a rotor blade,
[0050] [Fig. 4] Figure 4 is a larger-scale view of part of Figure 3.
[0051] [Fig. 5] Figure 5 is a schematic view of an external platform and the blades of a blade according to the invention,
[0052] [Fig. 6] Figure 6 is a view similar to that of Figure 5 and illustrates an alternative embodiment of the invention,
[0053] [Fig. 7] Figure 7 is a view similar to that of Figure 5 and illustrating another embodiment of the invention, [Fig. 8] Figure 8 is a schematic perspective view of the blades of a blade according to the invention,
[0054] [Fig.9] Figure 9 is a schematic perspective view of the blades of an alternative embodiment of a blade according to the invention,
[0055] [Fig.10] Figure 10 is a schematic view of the external platform and the blade slats of Figure 9.
[0056] Detailed description of the invention
[0057] Figures 1 and 2 have already been described above.
[0058] Figure 3 illustrates a rotor blade 100 according to prior art for an aircraft turbomachine 10, such as that illustrated in Figure 1.
[0059] The blade 100 is similar to the blade 34 of Figure 2 and comprises two platforms, respectively internal 102 and external 104, between which extends a blade 106 along an axis of extension A.
[0060] The blade 106 has leading edges 108 and trailing edges 110 and intrados 112 and extrados 114 faces which extend between the leading edges 108 and trailing edges 110.
[0061] The inner platform 102 is connected to a foot 116, and the outer platform 104 is connected to at least one sealing lip 118 that projects from the outer platform 102. In the example shown, there are two lip 118s. Each lip 118 extends substantially parallel to axis A.
[0062] The assembly formed by the platform 104 and the licks 118 forms a heel 103 of the dawn.
[0063] Each slat 118 has two faces 120, 122 located respectively on the leading edge 108 and the trailing edge 110, that is, on the upstream and downstream sides. Each slat 118 thus comprises an upstream face 120 and a downstream face 122. These faces 120, 122 may be substantially parallel to the axis A.
[0064] These faces 120, 122 are connected together by a radial end edge 124 or upper edge located on the opposite side to the blade 106, and two lateral edges 126, 128 located respectively on the side of the intrados 112 and extrados 114 faces of the blade 106.
[0065] Each of its slits 118 further includes a raised section 130 on at least one of its faces 120, 122, commonly called an elephant's foot. Each raised section 130 defines a maximum thickness Emax of the corresponding slit 118 measured in a direction perpendicular to the faces 120, 122.
[0066] As can be seen in figures 3 and 4, the extra thickness 130 of each slit 118 is located at one of the longitudinal ends of this slit 118, which generates disadvantages described above.
[0067] The invention offers an improvement to this technology, embodiments of which are illustrated in figures 5 to 12.
[0068] In general, the invention relates to a rotor blade 100 of the type illustrated in figures 3 and 4. As mentioned above, the blade 100 according to the invention comprises two platforms, respectively internal 102 and external 104, between which extends a blade 106 along an axis of length A, the blade 106 having leading edges 108 and trailing edges 110 and intrados 112 and extrados 114 faces which extend between the leading edges 108 and trailing edges 110.
[0069] Furthermore, a notion of "skeleton line" is defined. The blade 106 has, for any cross-section of the blade 106 perpendicular to the axis of elongation A, a virtual skeleton line Sq which connects the leading edge 108 to the trailing edge 110 and which is located at an equal distance from the intrados 112 and extrados 114 faces (figure 5).
[0070] Figure 5 shows for example the skeleton line Sq located on the blade 106 which is located closest to the external platform 104, and therefore the skeleton line Sq of the cross section of the blade 106 located at the connection of the blade to the external platform 104.
[0071] As shown in Figure 2, the internal platform 102 of the blade according to the invention is connected to a foot 116. Its external platform 104 is connected to at least one sealing lip 118 (and for example two lips 118). Each lip 118 projects from the external platform 104.
[0072] Each blade 118 has two faces 120, 122 located respectively on the leading edge side 108 and on the trailing edge side 110. These faces 120, 122 are connected together by an edge 124 located on the opposite side to the blade 106, and two lateral edges 126, 128 located respectively on the side of the lower surface faces 112 and upper surface faces 114 of the blade 106.
[0073] Each slit 118 also has an additional thickness 130 on at least one of its faces 120, 122, commonly called an "elephant's foot". This additional thickness 130 defines a maximum thickness Emax of the corresponding slit 118 measured in a direction perpendicular to the faces 120, 122.
[0074] The distinctive feature of the blade 100 according to the invention, which sets it apart from that of Figures 2 and 3, is that the additional thickness 130 of the blade or each blade 118 is located at a distance from the lateral edges 126, 128 and in line with the skeleton line Sq located closest to the external platform 104. In the embodiment of Figure 5, it can be seen that the additional thickness 130 is located on the face 120 of each blade 118. It can be seen that the additional thicknesses 130 of the two blades 118 can have different shapes but also different dimensions.
[0075] In the embodiment of figure 6, we see that an overthickness 130 is located on each face 120, 122 of each slat 118. We see that the overthicknesses 130 of the same slat 118 are identical, and that the overthicknesses 130 of one slat 118 are different from those of the other slat 118, in particular by their shapes and / or their dimensions.
[0076] In the embodiment of figure 7, we see that an overthickness 130 is located on the face 122 of each lick 118. We also see that the overthicknesses 130 of the licks 118 are identical.
[0077] Other embodiments of the slits 118 and the raised edges 130 are naturally conceivable within the framework of the definition of the invention. Generally, the raised edge 130 can be located in the middle of the corresponding slit 118, in a direction parallel to this slit 118.
[0078] Figure 8 illustrates a more concrete example of the realization of the overthicknesses 130 of the slats 118. Certain features of the invention will be explained in relation to this figure even though they can be applied to the embodiments illustrated in figures 5 to 7 and to variants not illustrated.
[0079] Advantageously, the overstud 130 extends from the external platform 106 to the edge 124 of the slit 118, which is visible in figure 8. Each overstud 130 advantageously has a triangular shape in at least one cutting plane P1, P2, P3 which crosses the slit 118 and passes through this overstud 130.
[0080] In the example shown, the overstud 130 has a triangular shape in a first cutting plane P1 which passes through the overstud 130 and is perpendicular to the radial direction A. The first cutting plane P1 passes here through the radially external end of the slit 118 and through the free radial end edge 124 of the slit 118.
[0081] The 130 reinforcement can have a triangular shape in a second cutting plane P2 that passes through the reinforcement 130 and is parallel to the radial direction A and perpendicular to the wingtip. The second cutting plane P2 passes here through a circumferential end of the reinforcement 130 located on the side of the lower surface 112 of the blade.
[0082] The shim 130 has a triangular shape in a third cutting plane P3 that passes through the shim 130 and is parallel to the radial direction A and perpendicular to the wingtip. The third cutting plane P3 may pass through a circumferential end of the shim 130 located on the upper surface 114 of the blade 106.
[0083] The additional thickness 130 is preferably formed by the juxtaposition of two right prisms 131a, 131b with triangular bases. A first right prism 131a comprises triangular bases 131a1, 131a2 located respectively on the lower surface 112 and upper surface 114 of the blade. One of the edges 131a3 of the first right prism 131a is located at the junction between the platform 104 and the wingtip 118.
[0084] A second right prism 131b comprises triangular bases 131b1, 131b2 located respectively on the side of the platform 104 and the free radial end edge 124 of the lick 118.
[0085] In the example shown, the right prisms 131 a1, 131a2 are joined by a junction plane P4 which is inclined with respect to said radial direction A. The ridge 132 is preferably formed by one of the edges 131 b3 of the second right prism 131b.
[0086] Each overthickness 130 preferably has its own thickness Esur measured in the direction perpendicular to the faces 120, 122, which decreases progressively from the external platform 106 to the said edge 124 and which is minimal (Esur_min) at the level of this edge 124, which is also visible in figure 8.
[0087] Each overthickness 130 can have its own width Lsur measured in a direction parallel to the corresponding slit 118, which decreases progressively from the external platform 106 to the edge 124 and which is minimal (Lsur_min) at the level of this edge 124. Alternatively, this width could be constant over the height of the slit 118.
[0088] Each overthickness 130 may include a ridge 132 or edge at the level of a greater thickness area of the overthickness 130. The ridge 132 may extend along the elongation axis A.
[0089] The ridge 132 can extend outwards from the platform 104 to the radially external end of the overthickness 130 and can be inclined at a determined angle with respect to the radial direction A, as in the example shown.
[0090] This ridge 132 can extend through the middle of the overthickness 130, in a direction parallel to the groove 118, as shown in Figure 8. This is also the case for each of the overthicknesses 130 in Figures 5 and 6. In this case, the overthickness 130 preferably has a thickness Esur measured in the direction perpendicular to the faces 120, 122, which gradually decreases (Esur) from the ridge 132 to each of the ends 130a, 130b of the overthickness 130 (Esur'). These ends 130a, 130b are located respectively on the side of the lateral edges 126, 128 of the corresponding groove 118.
[0091] The actual thicknesses Esur' at the ends 130a, 130b of the 130 reinforcement can be identical to within + / -10%. These thicknesses Esur' can be greater than the aforementioned thickness Esur_min as illustrated in the drawing.
[0092] The ends 130a, 130b of the overthickness 130 can be located at a distance from the lateral edges 126, 128, as is the case in figure 8 but also as is the case of the overthicknesses in the lower part of each of figures 5 and 6 (at the level of the lip 118 located on the side of the trailing edge 110 of the blade 106).
[0093] Alternatively, the ends 130a, 130b of the overthickness 130 can be located at the lateral edges 126, 128, as is the case for the overthicknesses in the upper part of each of figures 5 and 6 (at the level of the lip 118 located on the side of the leading edge 108 of the blade 106).
[0094] In yet another variant corresponding to the overthicknesses 130 of figure 7, the ridge 132 is located at one end 130a of the overthickness 130, this end 130a being located on the side of one of the lateral edges 128. This overthickness 130 can have an inherent thickness Esur measured in the direction perpendicular to the faces, which gradually decreases from the ridge 132 to the end 130b of the overthickness 130 opposite the ridge 132 and located on the side of the other of the lateral edges 126, as illustrated in figure 7.
[0095] Finally, as illustrated in Figure 8, the 130 overstud can have a general triangular or trapezoidal shape in at least one cutting plane, or even in two perpendicular cutting planes. The triangular shape is obtained, for example, in a cutting plane that is a transverse plane parallel to the platform 104. This plane is also perpendicular to the aforementioned elongation axis A. The triangular shape is obtained, for example, in a plane that is perpendicular to the platform 104 and the corresponding slit 118.
[0096] The 130 reinforcement can have a base 130c connected to the external platform 106, which has a generally triangular or trapezoidal shape, and a vertex 130d connected to the edge 124, which also has a generally triangular or trapezoidal shape. This geometry minimizes machining operations and thus facilitates production, but more complex shapes can be considered, particularly to emphasize certain functions according to specific needs.
[0097] Furthermore, this geometry and the reduction of thicknesses at the ends of the blades improve the mechanical behavior of the blade and its external platform in operation.
[0098] The embodiment variant of figures 9 and 10 differs from the dawn of figure 8 in particular in that the slats 118 taper in a circumferential direction from their median parts to their circumferential end edges 126, 128. The overthicknesses 130 are similar to those of figure 8.
[0099] The embodiment variant of figures 11 and 12 also has slits 118 which taper in a circumferential direction from their median parts to their circumferential end edges 126, 128. Each of the overthicknesses 130 here has a shape similar to that of figure 7.
[0100] From a quantitative point of view, it is possible to have:
[0101] - thicknesses at the lateral edges 126, 128 of the 118 edges which can go down to 0.3mm,
[0102] - minimum thicknesses (Esur_min) of the elephant's feet ranging from 0.8mm to 1.5mm,
[0103] - widths Lsur and Lsur_min of approximately 2mm, and
[0104] - thicknesses Esur at the base level 130c of the 118 strips between 2 and 6mm, and preferably between 3 and 4mm.
Claims
DEMANDS 1. Rotor blade (100) for an aircraft turbomachine (10), this blade (100) being intended to be mounted for rotation about an axis (X), extending radially with respect to this axis (X) in a radial direction (A) and comprising: - a blade (106) having an aerodynamic profile delimited by a leading edge (108), a trailing edge (110), an intrados face (112) and an extrados face (114) which extend between the leading edge (108) and the trailing edge (110), - a foot (116) at a first radial end of the blade (106), - a heel (103) at a second radial end of the blade (106), opposite the first radial end, the heel (103) comprising a platform (104) and at least one sealing flap (118) extending radially from the platform (104), each flap (118) being delimited by an upstream face (120) located on the leading edge side (108) and a downstream face (122) opposite the upstream face and located on the trailing edge side (110), the upstream (120) and downstream (122) faces being connected together by a free radial end edge (124) of the flap (118), and each flap (118) being further delimited by two opposing circumferential end edges (126, 128), one circumferential end edge being located on the side of the face of the intrados (112) and the other opposite circumferential end edge being located on the side of the extrados face (114) of the blade (106),said at least one slit (118) further comprising an overthickness (130) which extends axially in projection from the upstream face (120) or the downstream face (122) of the slit, the overthickness (130) being located at a distance from the circumferential end edges (126, 128) of the slit (118) and extending along said radial direction (A) from the platform (104) to the free radial end edge (124) of the slit (118), characterized in that the overthickness (130) has a triangular shape in at least one cutting plane (P1, P2, P3) which crosses the slit (118) and which passes through this overthickness (130), in that the overthickness (130) has a triangular shape in a first cutting plane (P1) which passes through the overthickness (130) and which is perpendicular to said radial direction (A), and in that the overthickness (130) has a triangular shape in a second cutting plane (P2) which passes through the overthickness (130) and which is parallel to said radial direction (A) and perpendicular to the lick (118).
2. Blade (100) according to claim 1, wherein the first cutting plane (P1) passes through the radially external end of the blade (118) and passes through the free radial end edge (124) of the blade (118).
3. Blade (100) according to claim 2, wherein the second cutting plane (P2) passes through a circumferential end of the overthickness (130) located on the side of the intrados face (112) of the blade (106).
4. Blade (100) according to claim 2 or 3, wherein the overthickness (130) has a triangular shape in a third plane of section (P3) which passes through the overthickness (130) and which is parallel to said radial direction (A) and perpendicular to the slit (118).
5. Blade (100) according to claim 4, wherein the third cutting plane (P3) passes through a circumferential end of the overthickness (130) located on the side of the extrados face (114) of the blade (106).
6. Blade (100) according to any one of the preceding claims, wherein said overthickness (130) comprises a ridge (132) which projects outwards from the platform (104) to the radially external end of the overthickness (130) and which is inclined at a determined angle with respect to said radial direction (A).
7. Blade (100) according to claim 6, wherein said ridge (132) extends in the middle of the overthickness (130), in a direction parallel to this slit (118).
8. Blade (100) according to claim 6, wherein said ridge (132) is located at a circumferential end (130a) of the overthickness (130), this circumferential end (130a) being located on the side of the lower surface (112) or the upper surface (114) of the blade.
9. Blade (100) according to any one of the preceding claims, wherein said overthickness (130) is formed by the juxtaposition of two right prisms (131a, 131b) with triangular bases, a first right prism (131a) whose triangular bases (131a1, 131a2) are located respectively on the side of the lower (112) and upper (114) surfaces of the blade and one of whose edges (131a3) is located at the junction between the platform (104) and the wingtip (118), and a second right prism (131b) whose triangular bases (131b1, 131b2) are located respectively on the side of the platform (104) and the free radial end edge (124) of the wingtip (118), the first and second right prisms (131a1, 131a2) being joined by a joining plane (P4) which is inclined with respect to said radial direction (A).
10. Blade (100) according to claim 9, depending on claim 6 or 7, wherein said crest (132) is formed by one of the edges (131 b3) of the second right prism (131b).
11. Turbine for an aircraft turbomachine (10), comprising several blades (100) according to any one of the preceding claims, each mounted in a cavity opening at the outer periphery of a turbine disk centered on an axis (X), the blades (100) being arranged circumferentially next to each other around an axis (X), the turbine (18, 20) further comprising an abradable annular element (52) which surrounds the blades (100) and in which the blade tips (118) of the blades (100) can cooperate by friction.