ASSEMBLY COMPRISING A BLADE AND AN ANGULAR BLADE TIMMING SYSTEM

Abstract

The invention relates to an assembly comprising an unducted propeller blade (10) and a system (34) for angularly setting the blade (10), for an aircraft turbomachine, which comprises: - a blade (10) whose root (14) has a bulb-shaped portion (32); - a system (34) for angularly setting the blade (10) around a setting axis (A), the angular setting system (34) comprising a bowl (58) which is intended to be arranged inside the external casing (73), which comprises a flared open upper end for axial insertion of the root (14), and in which the root (14) of the blade (10) is fixed axially by an immobilizing member (52); characterized in that it comprises at least one radial retention claw (77) in a radial space (E) reserved between the wall (58a) of the bowl (58) and the foot (14). Figure for the abstract: Figure 8

Description

Description Title of the invention: ASSEMBLY COMPRISING A BLADE AND A BLADE ANGULAR ADJUSTMENT SYSTEM Technical field of the invention

[0001] The present invention relates to the field of aircraft turbomachinery and in particular to- particular to the propulsive propellers of these turbomachines which have blades with variable calibration. Technical background

[0002] The state of the art includes, in particular, documents FR-A1-3 017 163 and FR- A1-3 080 322.

[0003] An aircraft turbomachine propeller can be shrouded, as is the case with a for example, a fan-cooled or unenclosed design, as is the case with an architecture of the type open-rotor for example.

[0004] = A propeller comprises blades that may have variable pitch. The turbomachine then includes a shimming system allowing the shimming angle of the blades to adapt the thrust generated by the propeller according to the different phases of theft.

[0005] — The design of a propeller blade involves several disciplines whose objectives are generally antagonistic. It must allow for aerodynamic performance. optimal (i.e., providing thrust while maximizing efficiency), guaranteeing a mechanical strength of the blade (that is, withstanding the mechanical stresses resulting from the static and dynamic loads) while limiting mass and signature acoustics. In particular, improving the aerodynamic performance of the propeller tends towards an increase in the BPR (By Pass Ratio), which translates into an increase- measurement of its external diameter and therefore of the span of the blades.

[0006] … In all prior art attachments, the blade foot is mounted in a metal barrel interfacing with the bearings to allow for variable shimming. These metal parts are an integral part of the blade. In the event of blade loss, these metal parts with a high density compared to the composite material the components of the rest of the dawn have significant energy. However, the energy of the released debris on an unfaired architecture is a fundamental element to optimize because this could hit the fuselage. This is therefore a factor to consider for the dimensions. sion of fuselage armor and, a fortiori, for the aircraft's mass.

[0007] — The invention aims to reduce the risk of the fuselage being struck by elements likely to damage it, even in the event of a failure of the means of fixing the blade to the leveling system. Furthermore, another way to optimize aerodynamic performance is to improve efficiency near the hub by carefully managing the quality of the airflow. Controlling this flow is all the more complex because the blade typically has variable pitch. A variable-pitch propeller essentially consists of a hub rotating around an axis of rotation and fitted with housings for blades that are pivotally mounted within these housings around angular pitch axes. These pitch axes extend radially from the hub's axis of rotation. Each blade has a root from which a blade extends. The root is mounted in a corresponding housing in the hub via a bearing oriented along the radial axis, which is interposed between an internal structure of the hub and the blade root to allow the blade to pivot. The hub generally includes an external casing that acts as an aerodynamic fairing for the hub. Openings are made in this casing through which the housings open, and through which the blade roots are inserted into the hub. Therefore, aerodynamic discontinuities exist in this fairing near the openings, firstly between the blade roots and the edges of the openings, and secondly between the blade roots and the blades. These aerodynamic discontinuities cause turbulence around the blade roots, which degrades the overall aerodynamic efficiency of the propeller. According to a known technical solution, a blade platform is used to cover the hole in the hub. The design of this platform ensures good geometric continuity at a specific pitch, and therefore at a specific flight point. This point is traditionally chosen as the point at which performance is to be optimized. When the pitch changes, the platform creates a gap with the hub. This break in the geometry then becomes a source of reduced efficiency for the blades. The platform is not a component systematically present in the state of the art of unfaired engine architectures. Furthermore, when present, the platform serves as a fairing element to achieve aerodynamic performance and has no structural function. Summary of the invention The invention relates to an assembly comprising an unfaired propeller blade and a blade angular adjustment system, for an aircraft turbomachine, which includes: - a blade comprising a blade connected to a connecting foot which is intended to be attached to a propeller hub and intended to be received in an associated opening of an external hub housing, the foot having a bulb-shaped portion; - an angular positioning system for the blade around a positioning axis, the angular positioning system comprising a bowl which is intended to be arranged inside the outer casing, which has an open flared upper end for the axial insertion of the foot into an annular wall of the bowl, and in which the foot of the blade is axially fixed by a locking member which is fixed to the bowl, the receiving bowl being intended to be mounted pivoting around the positioning axis relative to the hub; characterized in that it comprises at least one retention claw which extends radially from the wall of the bowl into a reserved radial space between the wall of the bowl and the foot, the claw being arranged axially opposite the bulb, the claw being capable of retaining the foot of the blade inside the bowl by contact with the bulb in the event of failure of the foot fixing member in the bowl. According to another aspect of the assembly made according to the teachings of the invention, the claw is made in one piece with a support member which is attached and fixed to the bowl. According to another aspect of the assembly made according to the teachings of the invention, the support member comprises an axial fixing tab which is fixed against an inner face of the bowl and from which the claw extends radially. According to another aspect of the assembly made according to the teachings of the invention, the support member comprises a radial fixing plate for a platform intended to close the associated opening of the housing, the fixing plate being arranged at an upper end of the fixing lug, the plate extending over an upper end edge of the bowl. According to another aspect of the assembly made according to the teachings of the invention, the claw is capable of flexing to cushion a displacement of the foot of the blade axially in the event of failure of the immobilizing element of the foot in the bowl. According to another aspect of the assembly made according to the teachings of the invention, the claw has a main section directed radially inwards from the fixing lug and an end section curved radially outwards to promote the deformation of the claw in case of axial displacement of the foot of the blade. According to another aspect of the assembly made according to the teachings of the invention, the claw is elastically deformable in bending over at least part of its bending movement. According to another aspect of the assembly made according to the teachings of the invention, in the fixed position of the foot of the blade in the bowl, the claw is arranged axially at a distance from the bulb of the foot. According to another aspect of the assembly produced according to the teachings of the invention, in fixed position of the foot of the blade in the bowl, the claw is arranged pre-stressed in flexion against the bulb of the foot. According to another aspect of the assembly made according to the teachings of the invention, the support member comprises a plurality of claws which are distributed regularly around the foot of the blade. According to another aspect of the assembly produced according to the teachings of the invention, the support member is made in several distinct sectors, each of which is fixed independently to the bowl, According to another aspect of the assembly made according to the teachings of the invention, the bowl has a shoulder face which extends radially inward from its inner face and which receives the support member in axial upward support. According to another aspect of the assembly made according to the teachings of the invention, the shoulder face is formed by the lower face of a rim which extends radially inwards from the upper end edge of the bowl. According to another aspect of the assembly made according to the teachings of the invention, the support member is radially supported outwards against the inner face of the bowl. According to another aspect of the assembly made according to the teachings of the invention, the support member is fixed to the bowl by means of a fixing screw which is received in through holes having a diameter greater than the diameter of its shank, the screw being screwed into a nut mounted with a radial play in the hole of the bowl or in the hole of the fixing member so that axial forces applied to the claw upwards pass only through the shoulder face against which the fixing member is supported. According to another aspect of the assembly made according to the teachings of the invention, the immobilizing member is formed by an immobilizing ring which extends around said axis and which is configured to be mounted around the foot, this immobilizing ring being configured to be mounted inside the bowl and to cooperate respectively with the foot and the annular wall of the bowl in order to ensure axial retention of the foot in the bowl. According to another aspect of the assembly made according to the teachings of the invention, a portion of the claw extends axially opposite the locking ring. According to another aspect of the assembly made according to the teachings of the invention, the immobilizing ring is a dog clutch ring which has external dog clutch teeth configured to cooperate with complementary internal dog clutch teeth of the annular wall of the bowl. According to another aspect of the assembly produced according to the teachings of the invention, the locking ring has a wedge shape in cross-section and is configured, under the effect of centrifugal forces in operation, to be axially stressed towards the outside of the bowl and to keep the blade foot axially tight by wedge effect. According to another aspect of the assembly produced according to the teachings of the invention, it further comprises: - a lower bearing guide extending around said axis and mounted around a lower part of the annular wall, - a guide bearing with an upper roller extending around said axis and mounted around an upper part of the annular wall, - at least one of the guide bearings having its inner ring integrated into said bowl. The invention also relates to a turbomachine, in particular for aircraft, comprising at least one assembly according to the teachings of the invention. Brief description of the figures Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for which reference should be made to the accompanying drawings in which: - Figure [Fig. 1] is a schematic perspective view of a propeller blade for an aircraft turbomachine, and illustrates the present invention. -Fig. 2 is a larger-scale view of part of Fig. 1 and shows the foot of the dawn, - [Fig.3] is a schematic perspective view with partial exploded view of the foot of the blade of [Fig.1], -Fig.4 is a schematic perspective view of the body of the foot of the dawn of [Fig.1], - [Fig. 5] is another schematic axial cross-sectional view of the blade root of [Fig. 1] and guide bearings, the cross-sectional plane extending along a chord of the blade, - [Fig. 6] is a schematic axial cross-sectional view of the blade root of [Fig. 1] and the guide bearings, the cross-sectional plane extending transversely to the blade chord, -Fig.7 is another schematic cross-sectional view along line VII-VII of [Fig.5], - [Fig.8] is a schematic axial cross-sectional view of the base of the blade of [Fig.1] and of an embodiment of an angular positioning system for this blade comprising a retention claw made according to a first embodiment of the invention, - [Fig.9] is a schematic perspective view of a bowl from the system of [Fig.8], - Fig. 10 is a schematic perspective view of a dog clutch ring system of the [Fig.8], -Fig.11 is a schematic perspective view of a locking ring of the system of [Fig.8], - [Fig.12] is a schematic perspective and partial axial section view of the blade foot and the system of [Fig.8], and shows a first assembly stage, the upper part of the bowl having been cut off to allow a better view of the inside of the bowl, - Figure [Fig. 13] is a schematic perspective and partial axial section view of the blade foot and the system of Figure [Fig. 8], and shows a second assembly stage, -Fig. 14 is a schematic perspective and partial axial section view of the blade foot and the system of Fig. 8, and shows a third assembly stage, - Figure [Fig. 15] is a schematic perspective and partial axial section view of the blade foot and the system of Figure [Fig. 8], and shows a fourth assembly stage, - Figure [Fig. 16] is a schematic perspective and partial axial section view of the blade foot and the system of Figure [Fig. 8], and shows a fifth assembly stage, - Figure 17 is a schematic perspective and partial axial section view of the blade foot and system of Figure 8, and shows a sixth assembly stage, and - [Fig.18] is a schematic axial cross-sectional view of the base of the blade of [Fig.1] and of a variant embodiment of an angular positioning system for this blade comprising a retention claw made according to the first embodiment of the invention, - [Fig.19] is a half-view similar to that of [Fig.8], which shows a second embodiment of the retention claw. - [Fig.20] is a half-view similar to that of [Fig.8], which represents a third embodiment of the retention claw, - Figure [Fig. 21] is a perspective view with partial axial section which schematically represents a retention claw made according to an alternative embodiment of the invention, - [Fig.22] is a view similar to that of [Fig.21] which represents another variant of the retention claw. Detailed description of the invention Figure [Fig.1] shows a blade 10 for a propeller of an aircraft turbomachine, this propeller being shrouded or unshrouded. The blade 10 comprises a blade 12 connected to a foot 14. The blade 12 has an aerodynamic profile and comprises an intrados 12a and an extrados 12b which are connected by a leading edge 12c and a trailing edge 12d, the terms upstream and downstream referring to the flow of gases around the blade 12 in operation. Blade 12 has a free upper end, called the apex, and a lower end that is connected to foot 14. In the example shown, the blade 10 is made of composite material using an injection molding process called RTM (Resin Transfer Molding). This process involves preparing a fibrous preform 18 by three-dimensional weaving, then placing this preform in a mold and injecting a polymerizable resin, such as an epoxy resin, which will impregnate the preform. After polymerization and hardening of the blade 12, its leading edge 12c is generally reinforced by a metal shield 20, which is attached, for example, by bonding. The blade 10 here includes a spar 22 which includes a part forming a core of the blade 12 and which is intended to be inserted into the preform 18 before the resin injection, and a part which extends on the opposite side to the top of the blade 12 to form part of the foot 14, called body 24. The spar 22 is preferably made of an epoxy organic matrix composite material reinforced with 3D woven carbon fibers, with the warp direction predominantly radially oriented and the weft predominantly oriented along the chord of the blade 12 at the aerodynamic rib height. However, the spar can also be a more mechanically advantageous assembly of different organic matrix composite materials (thermoset, thermoplastic, or elastomer) reinforced with long fibers (carbon, glass, aramid, polypropylene) in various fiber arrangements (woven, braided, knitted, unidirectional). Although not shown, the blade 12 can be hollow or solid and includes an internal cavity filled with a foam or honeycomb-type filler material. This filler material is installed around the spar 22 and is covered with a skin of organic matrix composite material to increase the impact resistance of the blade 12. The shield 20 can be titanium or titanium alloy, stainless steel, steel, aluminum, nickel, etc. The lower surface 12a or even the upper surface 12b of the blade 12 can be covered with a polyurethane film for erosion protection. The 'A' axis is an axis of extension for the blade 10 and the blade 12, and in particular an 'A' axis for setting the blade 10, that is to say, the axis around which the angular position of the blade 10 is adjusted. It is generally also a radial axis, extending along a radius relative to the axis of rotation of the propeller equipped with this blade 10. As shown in [Fig. 8], the blade 10 is attached by its foot 14 to a turbomachine hub 72 via an angular adjustment system 34, which will be described in more detail later. The hub 72 is here a ring that serves as a rotor disc. The hub 72 is fitted with an external housing 73 that constitutes an aero- dynamics of the hub 72. The housing 73 has an opening 75 for the passage of the blade 10, the foot 14 being thus housed inside the housing 73 while the blade 12 extends radially outside the housing 73. The foot 14 comprises a body 24 which has a particular shape more clearly visible in figures 3 to 7. The body 24 includes a bulb 32 which is connected to the blade 12 by a section radically narrower than the bulb 32, called stilt 30. In the embodiment shown in the figures, the foot 14 here comprises a metallic shaft 26 which at least partially encloses the body 24, and in particular the bulb 32, as will be explained in more detail later. The foot 14 is intended to be mounted in the hub 72 via the angular shimming system 34 which allows the blade 10 to pivot around its shimming axis "A" relative to the hub 72. The angular positioning system 34 comprises a bowl 58 having an annular wall 58a extending around the positioning axis "A". The bowl 58 serves as a pivot for the blade 10 relative to the hub 72. This wall 58a has a lower axial end closed by a bottom wall 58b, and an upper axial end open by a passage 59a radially delimited by an upper edge 59b of the wall 58a. The wall 58a is flared from bottom to top to allow the foot 14 of the blade 10 to be mounted inside the bowl 58 by axial insertion along the direction of the positioning axis "A". The bowl 58 is made in one piece. The wall 58a of the bowl 58 is delimited radially inwards by an internal face 59b. An elastically deformable member 66, such as a helical spring, extends around the shim axis "A" and is mounted inside the bowl 58. This member 66 bears axially on the upper surface of the bottom wall 58b, at the outer periphery of this surface in the example shown, and is configured to axially stress the foot 14 of the blade 10 outwards from the bowl 58, i.e. on the side of the top of the blade 10. As seen in [Fig.8], the bowl 58 is designed to be mounted pivotally around the shim axis "A" in the hub 72. More particularly, it is designed to support bearings 54, 56 which ensure the centering and guidance of the bowl 58 around the shim axis "A" relative to the hub 72. Bearings 54 and 56 can be part of the angular positioning system 34. In particular, at least one of the guide bearings can have its inner ring integrated into the bowl 58. This is the case here with the lower bearing 54, which has its inner ring 54a integrated into the bowl 58. In practice, this means that the bowl 58 includes a raceway 54a on its outer periphery on which the balls of the bearing 54 roll directly. This raceway The bearing comprises an annular surface with a concave curved cross-section. This raceway is located at the lower end of the bowl 58 and the wall 58a. The outer ring 54b of the bearing 54 is fixed to the housing 73, for example by shrink fitting. Furthermore, the bowl 58 is advantageously designed to apply a preload to the bearing 54. The outer ring 56b of the bearing 56 is fixed to the housing 73, for example by shrink fitting. Its inner ring 56a is engaged on and around the free upper end of the bowl 58 and the wall 58a. This end of the wall 58a includes an external cylindrical mounting surface 76 for the inner ring 56a and an external thread for screwing a nut 78 intended to bear axially against the inner ring 56a to hold it axially clamped against an external cylindrical shoulder 80 of the bowl 58. The wall 58a of the bowl 58 is flared outwards so that the bulb 32 is free to be inserted by axial sliding into the bowl 58. It is therefore necessary to provide a locking member to axially fix the bulb 32 in the bowl 58, and thus ensure the axial fixing of the blade 10 relative to the hub 72. For this purpose, the bowl 58 includes in its inner face 59b means configured to cooperate with a locking ring 52 forming said locking member. The immobilizing ring 52 extends around the shim axis "A" and is configured to be mounted around the foot 14. This immobilizing ring 52 is configured to be mounted inside the bowl 58 and to cooperate respectively with the foot 14 and the annular wall 58a of the bowl 58 in order to ensure the axial retention of the foot 14 in the bowl 58. Different embodiments of this immobilizing ring 52 will be detailed later. The blade 10 is also rotationally fixed to the bowl 58. The bottom wall 58b is configured here to cooperate by complementary shapes with the free end of the foot 14, and therefore with the end 28 of the body 24, so that the bowl 58 is rotationally fixed to the foot 14 around the axis. In this case, it is understood that the bottom wall 58b includes a recess 60 having a non-circular, and in particular rectangular, cross-section, and configured to receive the end 28 ([Fig. 8]). According to the teachings of the invention, the angular adjustment system 34 includes a safety device for retaining the foot 14 of the blade 10 inside the bowl 58 when the locking element, in particular the locking ring 52, can no longer perform its fastening function. This safety device prevents the blade 10 from striking the aircraft in the event of detachment. For this purpose, at least one retention claw 77 extends radially from the inner face 59b of the bowl 58 into a reserved radial space "E" between the wall 58a of the bowl 58 and the foot 14. A section of the claw 77 is arranged axially opposite the bulb 32 re- This constrains the passage section 59a of the bowl 58 to retain the foot 14 of the blade 10 inside the bowl 58 in case of failure of the foot 14 locking device in the bowl 58. In this way, when the foot 14 detaches from the bowl 58, it is subjected to a radially oriented centrifugal force that tends to pull it out of the bowl 58. The claw 77 forms a restriction in the passage section 59a of the bowl 58, which comes into contact with the foot 14. The centrifugal force exerted on the blade 10 is thus transmitted to the hub 72 via the claw 77 and the bowl 58 to retain the blade 10 in the bowl 58. The claw 77 forms a point protuberance which, in one embodiment, does not extend circumferentially in a continuous manner around the alignment axis "A". In an alternative embodiment of the claw 77 shown in [Fig. 21], the claw 77 has the shape of a wall of revolution. The claw 77 conformation, as described below, is defined along a couple in a plane that contains the alignment axis "A". According to another embodiment of the claw 77, which is shown in [Fig. 22], the claw 77 is in the form of segments of a wall of revolution. The claw 77 conformation, as described below, is defined along a couple in a plane that contains the alignment axis "A". As shown in [Fig. 8], the claw 77 is made in one piece with a support member 79 which is attached to and fixed to the bowl 58. The support member 79 has an axial fixing tab 81 which is fixed against the inner face 59b of the bowl 58 and from which the claw 77 extends radially. More specifically, the claw 77 extends radially from an upper end of the fixing tab 81. In the embodiments shown in Figures 21 and 22, several mounting tabs are distributed at specific points around the claw 77, forming a wall of revolution or segments of a wall of revolution. The portions shown in Figures 21 and 22 do not have mounting tabs. The mounting bracket 81 is, for example, fixed to the wall 58a of the bowl 58 by means of an assembly consisting of a screw 97 and a crimped nut 99. The nut 99 is, for example, made by crimping two rivets through the wall 58a of the bowl 50 or through the mounting bracket 81. The nut 99 is, for example, mounted with some play in the plane of the wall it passes through, the screw 97 enabling the fixing by tightening. The through holes 101 allowing the passage of the screw 97 have a diameter slightly larger than the diameter of the screw 97's shank in order to prevent the screw 97 from working in shear by keeping the screw shank away from the edges of the holes 101. The fixing is thus achieved essentially by tightening the screw 97 against the support. The support element 79 is made of a metallic material such as steel, titanium or a titanium alloy, such as TA6V, Inconel or aluminum. The claw 77 is likely to flex to cushion a movement of the foot 14 of The blade 10 axially rotates in the event of failure of the foot immobilizing device 14 in the bowl 58. Thus, the kinetic energy of the blade 10 is converted into deformation energy of the claw 77. The claw 77 has, in particular, a first bend 83a at its connection end with the fixing lug 81. The claw 77 is susceptible to flexing due to deformation of this first bend 83a. To provide greater flexibility to the claw 77, it has a main section 77a, which is generally straight, directed radially inwards from the mounting lug 81, and an end section 77b, which is also generally straight, curved radially outwards to facilitate deformation of the claw 77 in the event of axial displacement of the foot 14 of the blade 10. More specifically, the main section 77a is inclined towards the bottom of the bowl 58. The end section 77b extends radially towards the wall of the bowl 58 from its connection end with the main section 77a. The end section 77b is also inclined towards the bottom of the bowl 58 so as to extend substantially parallel to the axially opposite portion of the wall of the bulb 32. Thus, the claw 77 has a second elbow 83b which is arranged at the connection between the main section 77a and the end section 77b. The claw 77 is designed to make contact with the foot 14 via a contact face 85 formed by the lower face of the end section 77b. The contact face 85 extends substantially parallel to the opposite portion of the bulb wall 32. Thus, the contact surface 85 that comes into contact with the bulb 32 during axial movement of the blade 10 is large enough to withstand the pressure and retain the bulb 32 within the bowl 58. During an axial displacement of the blade 10, the bulb 32 of the foot 14 thus puts stress on the claw 77 by its contact face 85, causing the claw 77 to bend at its first and second bends 83a, 83b. The shock with the foot 14 is thus likely to be absorbed more effectively. The claw 77 is particularly elastically deformable, at least in part of its flexure. For example, the claw 77 is elastically deformable throughout its entire flexure movement. Alternatively, the claw 77 is elastically deformable over the first part of its bending movement, then the energy transmitted by the foot 14 is absorbed by plastic deformation of the claw 77 at the end of its bending movement. According to a first embodiment of the invention shown in [Fig.8], in the fixed position of the foot 14 of the blade 10 in the bowl 58, the claw 77 is arranged axially at a distance from the protruding portion of the foot 14. To prevent the blade 10 from gaining too much speed before the claw 77 slows it down in the event of a failure of the locking ring, it is preferable that the axial distance between the claw 77 and the bulb 32 of the foot 14 be reduced, for example to less than 2 mm. According to a second embodiment of the invention shown in [Fig. 19], in the fixed position of the foot 14 of the blade 10 in the bowl 58, the claw 77 is arranged pre-stressed in bending against the projecting portion of the foot 14. In [Fig. 7], the rest position of the claw 77 is shown in dashed lines. It can be seen that the claw 77 is here pushed outwards and upwards against its elastic restoring force. This embodiment allows the claw 77 to absorb the kinetic energy of the blade 10 from the beginning of its axial movement, before it has been able to gain speed. To improve the damping during the contact between the blade 10 and the claw 77, the contact face 85 of the claw 77 can be covered with a pad (not shown), for example made of elastomeric material. The support member 79 preferably comprises a plurality of claws 77 which are regularly distributed around the foot 14 of the blade 10 in order to distribute the forces. To facilitate its arrangement in the bowl 58, the support member 79 is made in several distinct sectors 79a, 79b, each of which is fixed independently to the bowl 58. Each sector 79a, 79b can be arranged in contact with two adjacent sectors 79a, 79b, or they can be arranged circumferentially at a distance from each other. Each sector 79a, 79b is equipped with at least one claw 77 to allow the retention effort of the blade 10 to be distributed over the entire circumference of the bowl 58. When the support is made of several distinct sectors 79a, 79b, each sector 79a, 79b is positioned radially by bearing against an annular portion of the inner face 59b of the bowl 58. Furthermore, the bowl 58 has at least one shoulder face 87 that extends radially inward from its inner face 59b to receive, by means of upward axial support, each sector 79a, 79b of the support member 79. More specifically, the upper end of the mounting tabs 81 bears axially against the shoulder face 87. Thus, each sector 79a, 79b is positioned both radially and axially so that each claw 77 is correctly positioned relative to the bulb 32. The shoulder face 87 is formed here by the lower face of a rim 89 that extends radially inwards from the upper end of the bowl 58. As will be explained later, in certain embodiments of the angular positioning system 34, it is necessary to provide a passage for inserting parts such as the locking ring. In this case, the rim 89 does not extend continuously around the entire circumference of the bowl 58, but is formed of discontinuous segments between which a circumferential space is reserved for the insertion of said elements. Advantageously, the support member 79 includes a radial plate 91 for fixing a platform 93 which is intended to close the associated opening 75 of the housing 73 in order to to provide better aerodynamic performance to the propeller. The mounting plate 91 is arranged at one upper end of the mounting bracket 81. It extends here above the upper end of the bowl 58 so as to support the platform 93, which completely closes the opening 75. The plate 91 extends radially from an inner end located near the strut 30, aligned with the inside of the bowl 58, to an outer end located aligned with the outside of the bowl 58. The plate 91 extends just below the level of the housing 73 so that the platform 93 is flush with the outer face of the housing 73. The plate 91, for example, has a ring shape around the "A" axis of the support. The plate 91 is, for example, made in several segments to facilitate its arrangement around the foot 14. Each segment can carry at least one claw 77. Thus, the support element 79 serves not only as a safety device in case of failure of the locking ring 82, but also as a support for the platform 93. It is therefore possible to reduce the number of parts forming the propeller, to reduce the weight of the propeller, but also to simplify the assembly of the propeller. Platform 93 can be made of metallic material or composite material. To adjust the position of the platform 93 along the alignment axis "A" so that it is perfectly flush with the outer face of the housing 73, shims 95 can be inserted between the platform 93 and the plate 91. The invention is now described as implemented in two particular and non-limiting embodiments of the angular support system 34. In these two embodiments, and as explained previously, the body 24 of the foot 14 has a particular shape, more clearly visible in Figures 3 to 7. Body 24 essentially comprises the three parts described previously, namely: - the free end 28 located on the side opposite the blade 12, - the stilt 30 located on the side of the blade 12, and - the bulb 32 located between the free end 28 and the stilt 30. The free end 28 has a general parallelepiped shape in the example shown. As can be seen in [Fig.7], this end 28 is offset or offset relative to the alignment axis "A" to achieve a keying or indexing function, as will be explained in more detail below. As shown in Figures 5 and 6, Pb is defined as a transverse plane, that is, a plane perpendicular to the alignment axis "A", passing approximately through the midpoint of end 28, measured along the alignment axis "A". This plane Pb is called the bottom or lower plane. Figure 7 shows the cross-sectional shape of end 28 in this plane Pb. This cross-section, called the bottom section, has a value or area, for example a maximum, denoted Sb, and has a generally rectangular shape in the example shown. As will also be described below, the end 28 is configured to cooperate with a blade 10 adjustment system 34. The 30 stilt has a relatively complex shape and can be considered as comprising: - two lateral sides 30a, 30b, located respectively on the intrados 12a and extrados 12b side of the blade 12, which converge towards each other along the "A" alignment axis and in the direction of the top of the blade 12 (see figures 4 and 6), and - two edges, respectively upstream 30c and downstream 30d, which on the contrary diverge from each other along the "A" alignment axis and in the direction of the top of the blade 12 (see figures 4 and 5). Ph is defined as a transverse plane passing through the stilt 30, and in particular its lower end. This plane Ph is called the upper plane. In this plane, the stilt may have a non-circular cross-section, for example oval, oblong, square, or rectangular. This cross-section, called the upper section, has a value or area, for example a maximum, denoted Sh. The bulb 32 has a general swollen or domed shape, this swollen or domed shape extending all around the "A" axis of alignment. We define Pm as a median plane passing through the bulb 32, and in particular through its largest cross-section, which is denoted Sm. This plane Pm is called the mean plane. In this plane, the bulb 32 may have a circular cross-section, although this cross-section is not a limiting factor. We understand that the Pm plane is located between the Pb and Ph planes. The cross-section of the bulb 32 decreases from the Pm plane (Sm) to the Ph plane, and also from the Pm plane to the Pb plane. Therefore, we understand that Sm is greater than both Sb and Sh. Furthermore, in the example shown, Sh is greater than Sb. The shaft 26 is here made of two half-shells 26a, 26b, as can be seen in [Fig.3], which are attached and fixed to the body 24, for example one on the side of the intrados 12a of the blade 12 and the other on the side of the extrados 12b of the blade 12. The half-shells 26a, 26b are thus joined at the level of a joint plane which passes through the alignment axis "A" and which extends substantially parallel to a chord of the blade 12. The barrel 26 is advantageously fixed to the body 24, preferably by gluing. The glue extends between the barrel and the body 24, all around the alignment axis "A". The barrel 26 is preferably metallic (steel, titanium, or a titanium alloy such as TA6V). The adhesive is, for example, an epoxy adhesive filled with thermoplastic or elastomer nodules, or reinforced with a fabric. This bonding assembly method is particularly well-suited due to the large contact area between the barrel cavity and the body 24, which can be made of composite material. The presence of an adhesive joint is advantageous because it allows for the correction of slight shape defects. The adhesive joint also helps to prevent the friction at the metal / composite interface and therefore increase the lifespan of the blade 10. Several options are considered for attaching the shaft 26 to the body 24. One option is to intentionally leave a gap between the two halves 26a and 26b of the shaft 26 once they are attached, in order to properly apply pressure during the polymerization of the adhesive joint. The polymerization phase can be carried out in an autoclave with the entire blade 10 inside a vacuum bag. However, it is also possible to perform this operation under pressure. The disadvantage of leaving a gap between the two halves 26a and 26b is that their positioning becomes less precise, thus requiring further machining of the external surface. A second possibility is to fit the half-shells together around the body 24 without any play. This strategy is possible, for example, by machining a blank already cut into two parts and held together during the machining operation to ensure the geometry of the external surfaces once the half-shells are reassembled. This allows control over the positioning and geometry of the external surface of the barrel 26 without the need for additional machining after bonding. In all cases, positioning pins or stops can be used to ensure the relative position of the barrel half-shells. The presence of an adhesive joint between the body 24 and the shaft is not mandatory, although it is highly advantageous. An alternative is to use preload washers (or springs) between the shaft and the composite body 24 to radially push the body 24 and press it against the shaft's bearing surfaces. The shaft's geometry can also be modified to slightly "clamp" the body 24 when the two shaft halves are fitted around the bulb 32. In this case, the shaft's deformation generates the preload. Therefore, tooling must be provided to maintain this position before final assembly. As can be seen in figures 5 and 6, the shaft 26 covers and fits at least part of the bulb 32 and the stilt 30, and has a complementary shape in section to the bulb 32, at the middle section Sm, and to the stilt 30, at the upper section Sh. More specifically, barrel 26 comprises three parts in the example shown: - a lower extremity 36 which has a generally annular shape (see figures 5-7) and which extends at the level of and around the free extremity 28 of the foot 14, - an upper extremity 38 which extends at the level of the plane Ph and which includes two lateral lips 40 applied to the flanks 30a, 30b of the stilt 30, and - a median part 42 applied to the bulb 32 and closely following its shape. The lips 40 bear against the sides 30a, 30b of the stilt 30 and allow the foot 14 of the blade 10 to be stiffened and its resistance to torsion around the A-axis of alignment. They also allow for the absorption of energy in the event of an impact on the blade 10, such as the ingestion of a bird. Fillets may be present on these lips to prevent wear or local damage to the body 24. The internal surfaces of the shaft 26, which are in contact with the body 24, serve as bearing surfaces. Compared to a pinned attachment, the bearing surface area is maximized by utilizing the entire circumference of the lower part of the blade 10. On a pinned attachment, only two distinct surfaces of the blade's foot 14, located on the lower and upper surfaces respectively, bear on bearing surfaces, while the surfaces of the blade's foot 14 located at the leading and trailing edges are free. Also compared to a pinned attachment, the height of the bearing surfaces in the radial direction is significantly greater, which also contributes to considerably increasing their area. This large bearing surface reduces contact pressure in all operating conditions. The barrel 26 includes two cylindrical surfaces 44, 46a for mounting shrink rings 48, 50. The shrink rings 48, 50 allow the half-shells 26a, 26b to be held tightly against each other and on the body 24. The shrink rings 48, 50 extend around the shim axis "A". The surface 44 is located on the lower end 36 and is oriented radially outwards with respect to the alignment axis "A". It receives the ring 48 by shrink fitting, which is engaged from below and bears axially on a cylindrical bearing surface located at the junction of the end 36 and the middle part 42 of the shaft 26. Surface 46a is located on the median part 42 and is oriented radially outwards with respect to the alignment axis "A". It receives the ring 50 by shrink fitting, which is engaged from above and bears axially on a cylindrical support located near the plane Pm. It can be seen that the surface 46a is located right next to a cylindrical surface 46b which is intended to receive a locking ring 52, as will be described below. Surfaces 44 and 46a, as well as rings 48 and 50, have different diameters in the example shown. Surface 46a has a larger diameter than surface 44, and therefore ring 50 has a larger diameter than ring 48. Surfaces 46a and 46b may have the same or different diameters. Surface 46b may, for example, have a slightly smaller diameter than surface 46a. This is particularly relevant when ring 50 is to be mounted with a predetermined radial clearance relative to surface 46b. Figures 5 and 6 show that ring 50 is located between planes Ph and Pm, and that ring 48 is located between planes Pm and Ps. Figures 5 and 6 also show the position of the rings 48, 50 and the planes Pm, Ph, Ps relative to the bearing supports 54, 56 which extend around the shim axis "A" and the foot 14. The levels 54, 56 are here two in number and are respectively a lower level 54 and an upper level. Bearings 54, 56 are of the ball bearing type. In the example shown, they have different diameters and their balls also have different diameters. The bearing 54 extends substantially between the planes Pm and Pb and therefore around a lower part of the bulb 32. It also extends around the ring 48. This bearing 54 has a smaller diameter than the other bearing 56, and its balls have a larger diameter than those of the other bearing 56. The bearing 54 is also an angular contact bearing. In the example shown, the bearing points or surfaces of the balls on the raceways of their rings 54a, 54b are located on a frustoconical surface S1 which extends along the alignment axis "A" and whose largest diameter is located on the side of the top of the blade 10. The bearing 56 extends substantially between the planes Pm and Ph and thus around an upper part of the bulb 32. It also extends around the ring 50. The bearing 56 is also an angular contact bearing. In the example shown, the bearing points or surfaces of the balls on the raceways of their rings 56a, 56b are located on a frustoconical surface S2 which extends along the alignment axis "A" and whose largest diameter is located on the side of the free end of the foot 14 of the blade 10. The position of the middle section between the two bearings 54 and 56 is very advantageous in terms of radial dimensions because part of the bearing height between the middle section and the upper section is located inside the bowl 58, unlike the state of the art with pinned fasteners integrated into a pivot. This helps to reduce the radial dimensions of the shimming system 34. Figures 8 to 17 illustrate a first embodiment of the angular positioning system 34 and in particular of the locking ring 52, and [Fig.18] illustrates a variant embodiment of the angular positioning system 34 and of this ring. The angular adjustment system 34 comprises a bowl 58 having an annular wall 58a extending around the adjustment axis "A". This wall 58a has a lower axial end closed by a bottom wall 58b, and an open upper axial end configured to allow the mounting of the foot 14 of the blade 10 inside the bowl 58. The bottom wall 58b is configured to cooperate by complementary shapes with the free end of the foot 14, and therefore with the end 28 of the body 24, so that the bowl 58 is rotationally fixed with the foot 14 around the axis. In this case, it is understood that the back wall 58b includes a recess 60 has a non-circular, and in particular rectangular, cross-section, and is configured to receive the end 28 ([Fig. 8]). As seen in [Fig. 5], this recess 60 is offset from the alignment axis "A" in a manner similar to the end 28 (see [Fig. 7]). This offset allows for indexing and keying during the insertion and assembly of the foot 14 in the bowl 58, as only one engagement position of the end 28 in the recess 60 is possible. The recess 60 is located on an upper or internal face of the bottom wall 58b of the bowl 58, which is therefore located inside the bowl 58 and oriented towards the side of the foot 14. The angular adjustment system 34 generates a torque at the blade foot 14 of the blade 10, which opposes the torsional moment resulting from aerodynamic and centrifuge forces. The end 28 of the foot 14 could be enclosed within the shaft 26, like the rest of the foot body 24. In this case, the foot would also have a non-circular shape to constrain its rotation. However, it is advantageous to leave this end of the body 24 protruding from the shaft, as mentioned above, in order to directly constrain the rotation of the body 24. This results in a more direct force path, with the torsional moment acting directly on the body 24. The lower section has dimensions strictly smaller than the maximum dimension of the middle section in order to limit the circumferential bulk at this height. Consequently, the shaft also has a smaller circumferential bulk at this height than at the middle section.This allows for a reduction in the diameter of the lower bearing located below the middle section. Therefore, the blade foot 14 can be integrated radially lower, significantly decreasing the theoretical hub ratio associated with the integration of the foot 14. Now, those skilled in the art know that a low hub ratio improves motor performance, particularly because the motor is more compact and therefore lighter. This last point is a very important advantage of this technical solution compared to the competition, which typically offers externally cylindrical shafts. The bottom wall 58b includes a lower or external face, which is located on the side opposite the foot 14, and which includes a cylindrical extension 62 extending along the pitch axis "A" and having an external thread or external straight grooves 64 for the rotational coupling of the angular pitch system 34 with a pitch changing mechanism which is not illustrated and which is common to the various angular pitch systems 34 and propeller blades 10. An elastically deformable member 66, such as a helical spring, extends around the alignment axis "A" and is mounted inside the bowl 58. This member 66 bears axially on the upper surface of the bottom wall 58b, at the outer periphery of this surface in the example shown, and is configured to axially load the foot 14 of the blade 10 outwards from the bowl 58, i.e., towards the apex of dawn 10. The component 66 rests on a cylindrical bearing surface 68 of the shaft 26. In the example shown, the component 66 is centered by engaging its upper end on and around a cylindrical rim 70 of the shaft, and by engaging its lower end on and around a cylindrical rim of the bowl 58 located at the external periphery of the bottom wall 58b. The component 66 extends here around the shrink ring 48. As can be seen in [Fig.8], the bowl 58 is designed to support the bearings 54, 56 which ensure the centering and guidance of the bowl 58 around the "A" alignment axis vis-à-vis the hub 72. Bearings 54 and 56 can be part of the angular positioning system 34. In particular, at least one of the guide bearings can have its inner ring integrated into the bowl 58. This is the case here with the lower bearing 54, whose inner ring 54a is integrated into the bowl 58. In practice, this means that the bowl 58 includes a raceway 54aa on its outer periphery, on which the balls of the bearing 54 roll directly. This raceway comprises an annular surface with a concave curved cross-section. This raceway is located here at the lower end of the bowl 58 and the wall 58a. The outer ring 54b of the bearing 54 is fixed to the hub 72, for example, by shrink fitting. Furthermore, the bowl 58 is advantageously designed to apply a preload to the bearing 54. The outer ring 56b of the bearing 56 is fixed to the hub 72, for example by shrink fitting. Its inner ring 56a is engaged on and around the free upper end of the bowl 58 and the wall 58a. This end of the wall 58a includes an external cylindrical mounting surface 76 for the inner ring 56a and an external thread for screwing a nut 78 intended to bear axially against the inner ring 56a to hold it axially clamped against an external cylindrical shoulder 80 of the bowl 58. The wall 58a of the bowl 58 further includes in its internal face 59b means configured to cooperate with the aforementioned locking ring 52. The immobilizing ring 52 extends around the shim axis "A" and is configured to be mounted around the foot 14. This immobilizing ring 52 is configured to be mounted inside the bowl 58 and to cooperate respectively with the foot 14 and the annular wall 58a of the bowl 58 in order to ensure the axial retention of the foot 14 in the bowl 58. In the embodiment of figures 8 to 17, this immobilizing ring 52 is a dog clutch ring which has external dog clutch teeth 84 configured to cooperate with complementary internal dog clutch teeth 82 of the annular wall 58a of the bowl 58. The teeth 82 of bowl 58 are more clearly visible in [Fig. 9]. These teeth are regularly spaced around the alignment axis "A". There are six of them in the non-limiting example shown. For example, each has an angular extension around the alignment axis "A", between approximately 20 and 30°. Each of the teeth 82 includes on its inner periphery a groove 86 oriented circumferentially with respect to the alignment axis "A". The grooves 86 of the teeth 82 form a discontinuous groove around the alignment axis "A". The dog clutch ring is more clearly visible in [Fig. 10]. Its 84 teeth are regularly spaced around the alignment axis "A". There are six of them in the non-limiting example shown. Each one has, for example, an angular extension around the alignment axis "A" of between approximately 20 and 30°. The teeth 84 are complementary to the teeth 82 and are configured to cooperate by dog ​​clutching with these teeth 82. Dog clutching is a well-known mounting method in the aeronautical field and will be illustrated by figures 12 to 17 illustrating a mounting method. As explained previously, and as shown in [Fig. 9], in this case, the rim 89 of the bowl 58 is formed by segments that are circumferentially spaced apart to allow the passage of the teeth 84 of the ring 52. The segments of the rim 89 are not necessarily arranged in coincidence with the teeth 82 of the bowl 58; they may be angularly offset. This makes it possible, for example, to provide a means of retaining the ring 52 inside the bowl 58 in the event of accidental removal of the ring 52. In Figures 12 to 17, the part of the bowl 58 containing the rim 89 has not been shown to allow for a clearer view and explanation of the operation of the angular positioning system 34. The ring 52 includes an internal cylindrical surface 52a intended to cooperate by sliding with the aforementioned surface 46b of the shaft 26. The ring 52 includes a second set of teeth 88, which extend axially upwards from the top of the blade 10 from an upper face 89 of the ring 52. These teeth 88 are also regularly spaced around the alignment axis "A". There are six of them in the example shown. They can be staggered with respect to the teeth 84, that is, the teeth 88 are axially aligned with the circumferential spaces between the teeth 84. By way of non-limiting example, each tooth 88 has an angular extension around the alignment axis "A" of between approximately 10 and 20°. Each of the teeth 88 has on its inner periphery a groove 90 oriented circumferentially with respect to the alignment axis "A". The grooves 90 of the teeth 88 form a discontinuous groove around the alignment axis "A". Figure 11 shows a locking ring 92 which is configured to be axially engaged between the dog teeth 82, 84 to prevent rotation of the ring 52. the inside of bowl 58. This ring 92 includes pads 94, here six in the non-limiting example shown, intended to be engaged in the inter-tooth spaces extending between the teeth 82 and 84. It is therefore understood that these pads 94 have shapes complementary to those of these spaces and are regularly spaced around the "A" alignment axis. In the example shown, the pads 94 are joined together by brackets 96 extending circumferentially between the pads 94. There are five brackets 96, each extending between two adjacent pads 94. Two of the pads 94 are intentionally not connected by a bracket so that the ring 92 is open. This simplifies the assembly by moving these pads closer together or further apart when mounting the ring in the angular positioning system 34. Each of the pads 94 has on its inner periphery a groove 98 oriented circumferentially with respect to the alignment axis "A". The grooves 98 of the pads 94 form a discontinuous groove around the alignment axis "A". The angular adjustment system 34 further includes an annular ring 100 which is only visible in [Fig.17]. The circlip 100 is mounted in the bowl 58 to axially lock the locking ring 92 in the bowl 58. The circlip 100 can also be split or opened to facilitate its assembly and is intended to be engaged in the grooves 86 of the teeth 82 of the bowl 58 as well as the grooves 98 of the pads 94 of the ring 92, when these grooves 86, 98 are all located in the same plane perpendicular to the alignment axis "A" and are arranged circumferentially with respect to each other to form a complete groove around the alignment axis "A" (see figures 16 and 17). We now refer to figures 12 to 17 which illustrate a method of mounting the assembly formed by a blade 10 as illustrated in [Fig.1] and an angular adjustment system 34 as represented in [Fig.8]. In the first step illustrated in [Fig. 12], the foot 14 of the blade 10 is engaged in the bowl 58 of the angular shimming system 34 by axial translation along the shimming axis "A", until the end 28 of the body 24 of the foot 14 engages in the recess 60 of the bowl 58. As can be seen in the drawing, the shrink-fit ring is already mounted captive around the shank 30 of the body 24 of the foot 14. Although not shown in this figure, the component 66 ([Fig. 8]) is compressed during the insertion of the foot 14 into the bowl 58. In the second step illustrated by Figures 12 and 13, the shrink-fit ring is positioned angularly around the alignment axis "A" so that its teeth 84 are aligned with the spaces between the teeth 82 of the bowl 58. The ring 52 is then moved axially within the bowl 58 until the ring 52 is engaged on the surface 46b of the barrel 26 and the teeth 84 are located just below the teeth 82, as illustrated in [Fig. 13]. The grooves 90 provided on the teeth can be used to grip the ring 52 with a suitable tool. In the third step illustrated in Figures 13 and 14, the ring 52 is rotated around the alignment axis "A" so that its teeth 82 and 84 are axially aligned with each other. Due to the angular extension of the teeth in the example shown, this angular displacement is on the order of 25-30°. The teeth 88 can be used to grip the ring 52 and rotate it using the aforementioned tool. The component 66, not shown, axially forces the foot 14 outward from the bowl 58, causing the teeth 84 to bear axially on the teeth 82. The foot 14 is thus held axially within the bowl 58 and the angular alignment system 34. In operation, the centrifugal forces applied to the blade 10 are transmitted by the teeth 82, 84 to the bowl 58, these forces being directly taken up by the bearing 54 whose inner ring 54a is integrated into the bowl 58, In the fourth step illustrated in Figures 15 and 16, the ring 92 is positioned angularly around the alignment axis "A" so that its pads 94 are aligned with the spaces between the teeth 82 and 84. The ring 92 is then moved axially within the bowl 58 until the pads 94 are engaged in these spaces. The bridges 96 can then bear against the teeth 84 of the ring 52. The ring 92 thus prevents any rotation of the ring 52 within the bowl 58. In the final step illustrated in [Fig. 17], the ring 100 is engaged in the grooves 86, 98, which are circumferentially aligned with each other. The ring 100 prevents accidental disassembly of the ring 92. The sectors 79a, 79b of the support member 79 are then positioned in the bowl 58. Each sector 79a, 79b is inserted into the space "E" reserved radially between the wall 58a of the bowl 58 and the stilt 30. Each sector 79a, 79b is then positioned by being pressed radially against the internal annular face 59b of the bowl 58 and axially upwards against the shoulder face 87 of the rim 89. Then the sectors 79a, 79b are fixed in this position, for example by means of riveted screws and nuts. According to the embodiment shown in [Fig.8], the claws 77 extend axially above the bulb 32 but they do not extend above the immobilizing ring 52. In the alternative shown in [Fig. 20], the free end of the claws 77 extends axially opposite the upper surface of the immobilizing ring 52. Thus, the claws 77 also contribute to retaining the immobilizing ring 52 inside the bowl 58. It is understood that the disassembly of the blade 10 is carried out by performing the aforementioned steps in reverse order. It is also understood that one of the essential steps in the assembly and disassembly of the base 14 concerns the retaining ring 52. This ring 52 can be manipulated from outside a turbomachine, which is particularly advantageous during maintenance operations. A blade 10 can be disassembled and removed from the propeller by disassembling and removing a minimal number of parts. We refer to [Fig.18] which illustrates a variant embodiment of the locking ring 52'. This ring 52' has a wedge shape in cross-section and is configured, under the effect of centrifugal forces in operation, to be axially stressed outwards from the bowl 58 and to keep the foot 14 of the blade 10 axially clamped by wedge effect. In the example shown, the 52° ring has a general trapezoidal shape in its axial half-section and comprises a lower surface 102 and two lateral surfaces, respectively internal 104 and external 106. The surfaces 102-106 are annular and extend around the "A" alignment axis. The 52” ring is engaged around the foot 14 and in the bowl 58 and bears axially by its surface 102 on the shrink ring 50, here by means of a washer 108. The external surface 106 of the ring cooperates by axial support and sliding with a complementary ring 110 mounted inside the bowl 58 and around the ring 52'. The 52” ring is sectorized and formed of several sectors arranged around the alignment axis “A” with a certain circumferential distance from each other. As a non-limiting example, there are six sectors, evenly distributed around the alignment axis “A”. Finally, a nut 112 is screwed onto an internal thread of the upper end of the bowl 58 and cooperates by axial bearing and sliding with the internal surface 104 of the ring 52”. Screwing and tightening the nut 112 causes both an axial displacement of the sectors of the ring 52' bearing against the washer 108, and a radial load on these sectors against the complementaryly shaped ring 110. Any assembly play is then eliminated. The shaft 26 includes a cylindrical shoulder 114 bearing against a cylindrical shoulder 116 complementary to the bowl 58, here at the junction between the middle part 42 and the lower end of the shaft 26. The advantage of this variant is in particular to take up the centrifugal forces in order to achieve the retention of the blade 10 but also to replace the aforementioned component 66 by directly applying a prestress between the shaft 26 and therefore the foot 14 of the blade 10, and the inner ring 54a of the bearing 54. The support element 79, which includes the claws 77 and supports the plate 95, is indeed understood as applicable to this embodiment, as shown in [Fig.18]. Other, unrepresented, alternative implementations are possible, including: the half-shells 26a, 26b of the barrel 26 can be attached to the body 24 by bolting, riveting, welding, etc.; The adhesive used to bond the barrel 26 to the body 24 can be an epoxy adhesive, but it can also be an elastomer or a thermoplastic adhesive. It is also possible to use a non-stick film to allow for relative movement while limiting wear from friction; Regarding the barrel / body interface 24, several technical solutions can also be combined from those proposed (bonding, pre-stressing by washers or springs, pre-stressing by the geometry of the barrel); these solutions can be combined regardless of the existence of a gap between the two parts of the barrel; Although less advantageous, the radial position of the bearing ensuring the centrifugal retention of the blade 10 can be reversed with the radial position of the bearing which ensures the absorption of bending moments from aerodynamic and centrifuge forces. In all these embodiments, when the locking ring 52, 52" is no longer able to immobilize the blade foot 14 of the blade 10, the bulb 32 moves axially outwards along the alignment axis "A". The bulb 32 comes into contact with the claws 77 in such a way as to cause their deformation, which sufficiently slows the blade 10 so that it can be held inside the bowl 58 by the claws 77 thus deformed. The centrifugal forces exerted by the blade 10 are transmitted to the hub via the mounting lug 81, which bears axially against the shoulder face 87. This transmits the centrifugal force to the bowl 58, which in turn transmits the force to the hub 72 via the bearings 54, 56. In this way, the centrifugal force advantageously does not pass through the mounting screws of the support members 79, which are received with a sufficient radial clearance in their respective orifices.

Claims

Claims

1. Assembly comprising an aubc (10) of unducted propeller and a system (34) angular setting of the blade (10), for a turbomachine aircraft, which includes: - a blade (10) comprising a foot (14) which is intended to be attached to a hub (72) of the propeller and which is intended to be received in a opening (75) associated with an external casing (73) of hub (72), the foot (14) having a bulb-shaped portion (32); - a system (34) for angularly setting the blade (10) around an axis (A) of wedging, the angular wedging system (34) comprising a bowl (58) which is intended to be arranged inside the external casing (73), which has a flared open top end for axial insertion of the foot (14) in an annular wall (58a) of the bowl (58), and in which the foot (14) of the blade (10) is fixed axially by a member (52) immobilization which is fixed to the bowl (58), the receiving bowl (58) being intended to be mounted pivoting around the axis (A) of timing relative to to the hub (72); - at least one retention claw (77) which extends radially from the wall (58a) of the bowl (58) in a radial space (E) reserved between the wall (58a) of the bowl (58) and the foot (14), the claw (77) being arranged axially opposite the bulb (32), the claw (77) being capable of retaining the foot (14) of the blade (10) inside the bowl (58) by contact with the bulb (32) in case of failure of the foot fixing member (14) in the bowl (58), characterized in that the assembly further comprises: - a platform (93) intended to close the associated opening (75) of the casing (73), and in that the claw (77) is made in one piece with a member (79) support which is reported and fixed to the bowl (58), and which comprises a radial plate (91) for fixing said platform (93), the plate (91) extending above an upper end edge of the bowl (58).

2. Assembly according to the preceding claim, characterized in that the support member (79) comprises an axial fixing lug (81) which is fixed against an internal face (59b) of the bowl (58) and from which the claw (77) extends radially.

3. Assembly according to claim 2, characterized in that the tray (91) fixing is arranged at an upper end of the leg (81) of fixation.

4. An assembly according to any preceding claim, ca- characterized in that the claw (77) is capable of flexing to cushion a displacement of the foot (14) of the blade (10) axially in the event of de- failure of the member (52) for immobilizing the foot (14) in the bowl (58).

5. Assembly according to the preceding claim, characterized in that the claw (77) has a main section (77a) directed radially towards the interior from the fixing lug (81) and an end section (77b) curved radially outwards to promote deformation of the claw (77) in the event of axial displacement of the root (14) of the blade (10).

6. Assembly according to any one of claims 4 and 5, characterized in that the claw (77) is elastically deformable in flexion on at less part of its bending movement.

7. An assembly according to any preceding claim, ca- characterized in that in the fixed position of the foot (14) of the blade (10) in the bowl (58), the claw (77) is arranged axially at a distance from the bulb (32) of the foot (14).

8. Assembly according to any one of claims 1 to 6, characterized in that in the fixed position of the foot (14) of the blade (10) in the bowl (58), the claw (77) is arranged prestressed in bending against the bulb (32) of the foot (14).

9. An assembly according to any preceding claim, ca- characterized in that the support member (79) comprises a plurality of claws (77) which are distributed regularly around the foot (14) of dawn (10).

10. An assembly according to any preceding claim, ca- characterized in that the support member (79) is made of several distinct sectors (79a, 79b) each of which is fixed independently to the bowl (58).

11. An assembly according to any preceding claim, ca- characterized in that the bowl (58) has a shoulder face (87) which extends radially inwardly projecting from one face (59b) internal of the bowl (58) and which receives the member (79) in axial support upwards of support.

12. Assembly according to the preceding claim, characterized in that the support member (79) is fixed to the bowl (58) by means of a screw (97) of fixing which is received in orifices (101) of passage having a diameter greater than the diameter of its rod, the screw (97) being screwed into a nut (99) mounted with radial clearance in the orifice (101) of the bowl (58) or in the orifice (101) of the member (79) of fixing so that axial forces applied to the claw (77) upwards pass only through the shoulder face (87) against which the fixing member (79) is supported.

13. An assembly according to any preceding claim, ca- characterized in that the immobilizing member is formed by a ring immobilization (52, 52) which extends around said axis (A) and which is configured to be mounted around the foot (14), this ring immobilizer (52, 52') being configured to be mounted on the interior of the bowl (58) and to cooperate respectively with the foot (14) and the annular wall (58a) of the bowl (58) in order to ensure axial retention of the foot (14) in the bowl (58).

14. Assembly according to the preceding claim, characterized in that a portion of the claw (77) extends axially opposite the ring (52) immobilization.

15. Turbomachine, in particular for an aircraft, comprising at least one assembly according to any one of the preceding claims.