Fixed turbine blade of a turbomachine including variable pitch blades

Abstract

A blade (7) of a static blade of a turbomachine, comprising: - a blade foot (11) comprising a first portion (11a) configured to be fixed on a hub (8) of the turbomachine and a second portion (11b) extending radially from the first portion; - a first and a second baseplate (14, 15) extending on either side of the second portion and configured to transmit forces between the blade and the hub, the first and second baseplate each comprising a first support (14a, 15a) mounted on the first portion at a distance from the second portion or the hub, a second support (14b, 15b) mounted on the second portion (11b), and a connecting flange (14c) connecting the two supports; and - a platform (20) comprising a radially internal portion (20b) mounted on all or part of the first supports and a radially external portion (20a) mounted on the second portion. Figure for the abbreviation: Fig. 2A

Description

Title of the invention: Fixed turbomachine blade comprising variable pitch blades technical field

[0001] The present invention relates to the field of turbomachinery, in particular a fixed blade of a turbomachine, for example a fixed blade comprising stator blades with variable pitch, each fixed to a pivot. The invention is particularly applicable to the unshrouded or shrouded stator of a turbomachine. STATE OF THE ART

[0002] Turbomachines comprising at least one unducted propeller are known by the English term "open rotor" or "unducted fan." Such turbomachines may comprise two unducted, counter-rotating propellers (known by the English acronym CROR for "Contra-Rotating Open Rotor") or a single unducted propeller and a stator comprising several stator blades (known by the English acronym USF for "Unducted Single Fan"). The propellers may be located at the rear of the gas generator (or engine) so as to be of the pusher type or at the front of the gas generator so as to be of the tractor type. These turbomachines are turboprops, which are distinguished from turbojets by the use of a propeller outside the nacelle (unducted) instead of an internal fan.This allows the dilution rate to be increased very significantly without being penalized by the mass of the housings or nacelles intended to surround the propeller or fan blades.

[0003] The stator blades of the rectifier are generally mounted on a hub which carries the primary and secondary flow separation nozzle, the primary and secondary flows circulating respectively in a primary channel and around the inlet casing. Unlike the upstream propeller of a USF-type turbomachine, the stator blades of the rectifier are fixed in rotation relative to the axis of rotation of the upstream propeller and therefore do not experience centrifugal force.

[0004] The stator blades extend from the inlet housing and may optionally have variable pitch. In this case, each stator blade root is pivotally mounted about a pitch axis and connected to a pitch-changing system mounted in the turbomachine. However, the integration area of ​​the stator blade root and pivot is highly constrained by the presence of numerous surrounding components.

[0005] Current propeller fastening technologies, however, do not meet the need for fastening the stator blades of a turbomachine because they use centrifugal force generated by the propeller's rotation to press the blade's foot into its attachment. However, in a static blade, the absence of rotation and therefore of centrifugal force prevents the use of this fastening method.

[0006] The blades of static turbine blades are therefore generally fixed by bolting to a metal bracket comprising bolts extending either axially or radially, so as to fix the blade root to the leading edge. This type of bracket, however, is bulky tangentially, particularly when the bolts are mounted radially, which poses integration difficulties in the turbomachine.

[0007] In addition, the attachment is subjected to significant bending forces and the areas of the blade foot into which the bolts are inserted form stress concentration zones which undergo an asymmetrical force due to the pressure differences experienced by the intrados and extrados of the blade. EXPOSED

[0008] One aim of the present application is to remedy the aforementioned disadvantages, by proposing a system for fixing the blades of a static blade of a turbomachine, the size of which is reduced while ensuring suitable retention of the blades of the static blade.

[0009] To this end, a static blade of a turbomachine is proposed according to a first aspect, comprising:

[0010] - a blade foot comprising a first portion configured to be fixed on a hub of the turbomachine and a second portion extending radially from the first portion with respect to an extension axis of the blade;

[0011] - a first and a second base extending on either side of the second portion and configured to transmit forces between the blade and the hub, the first and second bases each comprising a first support configured to be mounted on one of the first portion of the blade foot at a distance from the second portion and the hub, a second support configured to be mounted on the second portion of the blade foot at a distance from the first portion and the first support, and a connecting flange joining the first support and the second support; and

[0012] - a platform comprising a radially internal part mounted on all or part the first supports and a radially external part mounted on the second portion of the blade.

[0013] Some preferred but not limiting features of the dawn described above are the following, taken individually or in combination: - the first and second portions of the blade foot are connected by a junction having a radius of curvature, the second support of the first base and the second base being fixed to the blade foot in an area of ​​the second portion positioned radially at a distance from the junction, and the first support of the first base and of the second base being fixed to the first portion or to the hub in an area at a distance tangentially from the junction. - the first support of the first and second base is mounted on the first portion of the blade foot so that a free edge of the first support is closer to a free end of the first portion of the blade foot than to the junction. - the first support of the first and second base is mounted on the hub, at a distance from the first portion of the blade foot. - the blade has several first bases and several second bases, for example at least two and at most four first and second bases, the first and second bases extend along the blade, between a leading edge and a trailing edge of the blade. - the blade has first fixing elements configured to fix the first supports to the hub, and second fixing elements configured to fix the second supports to the second portion of the blade foot. - the first and second supports each have a free edge, all or part of the free edges of the first and second supports being chamfered. - the platform is either monolithic with at least one of the first and second bases, or added and fixed to at least one of the first and second bases by means of third fixing elements.

[0014] The invention also relates to a turbine blade of a turbomachine comprising at least one blade as defined above and a hub, the blade being mounted in the hub by means of first fastening members.

[0015] Advantageously, the blade is mounted in the hub by means of a fastener, the fastener being pivotally mounted relative to the hub around a radial shim axis. DESCRIPTION OF THE FIGURES

[0016] Other features, objectives and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0017] Fig. 1 illustrates a schematic view, in axial and partial section, of an example of a turbomachine which may include a blade of a static blade according to an embodiment;

[0018] Figure [Fig. 2A] is a schematic cross-sectional view of an example embodiment of a blade of a static blade according to a first embodiment; and

[0019] The [Fig.2B] is a schematic cross-sectional view of an example of an embodiment of a blade of a static blade according to a second embodiment.

[0020] Throughout all the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0021] A turbomachine 1, in particular for aircraft, conventionally comprises at least one fan or at least one propeller 2, a compression section 3, a combustion chamber 4, a turbine section 5 downstream of the combustion chamber 4, and an exhaust casing.

[0022] The invention applies to any static (i.e., non-rotating) blade 6 of a turbomachine 1, whether it is a stator blade 6 of a fan or propeller 2, a stator blade 6 of the compression section 3, or a distributor blade 6 of the turbine section 5. By way of example, the turbomachine 1 may be a USF-type turboprop comprising an unshod propeller 2, in which case the static blade 6 is unshod and extends downstream of the propeller 2 (see [Fig. 1]). In another example, the turbomachine 1 may be a turbojet comprising a shod fan, in which case the static blade 6 may correspond to the shod stator extending downstream of the fan, which is known by the English designation "outlet guide vane".

[0023] In the present application, upstream and downstream are defined with respect to the direction of gas flow through the static blade 6. The axis of rotation around the rotor of the propeller 2 (respectively, of the fan) is called the X-axis. The axial direction corresponds to the direction of the X-axis, and a radial direction is a direction perpendicular to and passing through this X-axis. Furthermore, the circumferential (or tangential) direction corresponds to a direction perpendicular to and not passing through the X-axis. Unless otherwise specified, internal and external are used with reference to a radial direction such that the internal part or face of an element is closer to the X-axis than the external part or face of the same element.

[0024] The blade 7 will thus be defined with respect to the axis X of the rotor associated with the static blade 6 (whether it is the axis of rotation of the blower or the propeller 2 for a blower straightener, the axis of rotation of the compressor rotor for a straightener with a compression section 3 or the axis of rotation of the turbine rotor for a distributor with a turbine section 5 on which it is intended to be mounted).

[0025] Optionally, the blade 7 has variable pitch, i.e., the blades 7 are pivotally mounted about a pitch axis Y on a hub 8 of the blade 6 (the pitch axis Y being fixed relative to the X axis). This is not, however, limiting; the blades 7 can be fixed relative to the hub 8 when the blower is shrouded, the hub 8 then corresponds to the ferrule of the intermediate casing (which is located between the low pressure compressor casing and the high pressure compressor casing).

[0026] The static blade 6 thus comprises a hub 8 mounted fixed relative to a housing 9 of the turbomachine 1. It is therefore non-rotating. The blades 7 of the blade 6 extend substantially radially with respect to the X-axis.

[0027] In an embodiment in which the blades 7 have variable pitch, the blade 6 includes an actuation mechanism 10 for modifying the pitch angle of the blades 7 of the blade 6 in order to adapt the performance of the turbomachine 1 to the different phases of flight. Furthermore, the foot 11 of each blade 7 is mounted in the hub 8 by means of a fastener 8a (or pivot). The fastener is rotatably mounted relative to the hub 8 about a pitch axis Y. More precisely, the fastener is rotatably mounted inside a housing formed in the hub 8, by means of rolling elements such as balls or any other element capable of performing this function.

[0028] In the following description, for the sake of simplicity, the invention will be described in the case of a variable-pitch blade 7 whose foot is mounted in the hub 8 via the attachment 8a. However, the present description is not limited to this configuration and applies mutatis mutandis to a fixed blade 7 whose foot is mounted directly on the hub 8.

[0029] The blade 7 includes a blade 12 with an aerodynamic profile suitable for being placed in an airflow when the turbomachine 1 is in operation in order to generate lift, as well as a blade foot 11 configured to be fixed to the hub 8 of the blade 6.

[0030] The blade 7 is shaped to define an intrados 7a, an extrados 7b, a leading edge, and a trailing edge. As is known per se, the leading edge is configured to extend in relation to the flow of gases entering the turbomachine 1. It corresponds to the forward part of an airfoil that faces the airflow and divides the airflow into an intrados flow and an extrados flow. The trailing edge, for its part, corresponds to the rear part of the airfoil, where the intrados and extrados flows meet.

[0031] The blade foot 11 comprises a first portion 1a configured to be fixed to the hub 8 via the attachment 8a, and a second portion 11b extending radially with respect to the X axis from the first portion 1a. The second portion 11b is therefore connected to the blade 12, possibly monolithically.

[0032] In a first embodiment, the blade 7 comprises a composite material including a fibrous reinforcement embedded in a matrix, for example a polymer matrix. The fibrous reinforcement may include three-dimensional woven or knitted fibrous arrangements. It is further made such that it includes Warp threads that extend continuously both inside the airfoil portion 12 of the blade and inside the blade root portion 11. Alternatively, the fibrous reinforcement may comprise two-dimensional layered fibrous arrangements. The fibers of the fibrous reinforcement comprise at least one of the following materials: carbon (typically silicon carbide), glass, aramid, polypropylene, and / or ceramic (typically an oxide ceramic). The matrix typically comprises an organic matrix (thermoset, thermoplastic, or elastomer) or a carbon matrix. For example, the matrix comprises a plastic material, typically a polymer, such as epoxy, bismaleimide, or polyimide.

[0033] The fibrous reinforcement may, in particular, comprise two skins, which are joined to each other and extend generally opposite each other. In particular, the skins are joined at the blade tip along the entire chord of the blade 7, at the leading edge and at the trailing edge. The skins may be monolithic and made in one piece from a fibrous preform with a variable thickness. Alternatively, a first skin may be formed from a first part of the fibrous reinforcement to form the lower surface and a second skin may be formed from a second part of the fibrous reinforcement to form the upper surface, the first and second parts of the reinforcement then being joined, for example, near the blade tip.

[0034] A debonding is then made in the fibrous reinforcement at the radially internal end of the skins opposite the blade head, so that this end is free. The radially internal ends of the skins then form the first portion 1la and are separated from each other so as to extend tangentially against the attachment 8a. The radially internal ends of the skins each have a free end 1le. The free end 1le of the skin intended to form the intrados face 7a of the blade 7 extends on one side of the second portion 11b and forms an intrados part of the foot 11, while the free end 1le of the skin intended to form the extrados face 7b of the blade 7 extends on the other side of the second portion 11b and forms an extrados part of the foot 11.

[0035] Alternatively, the blade 7 is made of metal: in this case, the blade foot 11 is shaped so that its radially internal end comprises an intrados part and an extrados part which flare out from the second portion so as to extend substantially tangentially against the attachment to form two panels, each panel having a free end 1 extending on the intrados or extrados side, respectively.

[0036] The first and second portions 1a and 11b of the blade foot 11 are connected by a junction 1Id. In one embodiment, and particularly when the blade 7 is made of composite material, the junction 1Id has a radius of curvature R so to limit the risk of breakage between the first portion 1la and the second portion 11b during force transmission between the two, in particular by minimizing out-of-plane and shear stresses. The fastener 8a includes an external surface 8b configured to receive the first portion 1la. The first portion 1la is thus positioned against the external surface 8b.

[0037] The blade 7 further comprises a first base 14 and a second base 15 extending on either side of the second portion 11b of the blade foot 11. For example, the first base 14 is disposed on the intrados side of the blade foot 11 and the second base 15 is disposed on the extrados side of the blade foot 11. The first base 14 and the second base 15 are configured to transmit forces between the blade 7 and the hub 8 (via the attachment 8a).

[0038] In one embodiment, the blade 7 may comprise several first bases 14 and several second bases 15. For example, the blade 7 may comprise at least two first and two second bases 14 and 15. Considering the usual length (chord) of stator blades 7, the blade 7 may comprise at most four first and four second bases 14 and 15. For example, the blade comprises three first and three second bases 14 and 15. The first bases 14 and the second bases 15 are then substantially identical to each other. In all embodiments with several first and second bases 14, 15, the first bases 14 and the second bases 15 are arranged so as to extend along the blade 7 between the leading edge and the trailing edge, i.e. along the chord of the blade 7.The first bases 14 can, for example, be arranged on the lower surface 7a of the blade root 11 and the second bases 15 on the upper surface 7b of the blade root 11. In other words, the first bases 14, and respectively the second bases 15, are substantially aligned along the blade root 1a between the leading edge and the trailing edge. Preferably, two successive first bases 14 or two successive second bases 15 along the blade root 11 are then spaced at a constant distance, in order to distribute the load evenly along the blade root 11.

[0039] The first base 14 and the second base 15 each comprise a first support 14a, 15a, a second support 14b, 15b, and a connecting flange 14c, 15c, extending between the first and second supports 14a, 14b, 15a, 15b of the base 14, 15.

[0040] The second support 14b, 15b of each of the bases 14, 15 is mounted on the blade 7, and more specifically mounted on the second portion 11b of the blade foot 11. In particular, the second support 14b, 15b of each base 14, 15 can be fixed to the second portion 11b of the blade foot 11 by fasteners 16 such as bolts, rivets or any other equivalent fastening means. In order to limit the To distribute the load evenly, the first and second bases 14 and 15 and their first supports 14a, 15a are preferably arranged symmetrically with respect to the blade foot 11, i.e., opposite each other. Furthermore, in this configuration, a single fastening element 16 can secure the second supports 14b, 15b to a first and second base 14, 15 facing each other, the second fastening element 16 being, for example, mounted through the second supports 14b, 15b and the second portion 11b of the blade foot 11.

[0041] The first support 14a, 15a of each of the bases 14, 15 is configured to be secured to the hub 8 via the fastener 8a by means of fastening members 13. More specifically, in a first embodiment, an example of which is illustrated in [Fig.2A], the first support 14a, 15a of each of the bases 14, 15 is mounted directly on the hub 8 (here, via the fastener 8a) and in a second embodiment, an example of which is illustrated in [Fig.2B], the first support 14a, 15a of each of the bases 14, 15 is mounted on the hub 8 (here, via the fastener 8a) by means of the first portion 1a of the blade foot 11.

[0042] The fastening members 13 are therefore configured to secure the first portion of the blade 7 to the hub 8 (via the fastener 8a). In one embodiment, the fastening members 13 are configured to fix the first portion 1a to the external surface 8b of the fastener 8a. For example, the fastening members 13 include screws, bolts, or any other suitable fastening member radially fixing the first portion 1a to the external surface 8b. In one embodiment, the fixing members secure the blade 7 to the hub 8 (via the attachment 8a) on either side of the blade foot 11, that is to say that one or more fixing members 13a fix for example the intrados part of the first portion lia on the external surface 8b, and that one or more fixing members 13b fix the extrados part of the first portion lia on the external surface 8b.

[0043] Thus, each of the bases 14 and 15 is configured to absorb the majority of the forces between the blade 7 and the hub 8 (via the attachment 8a), so that these forces no longer pass through the junction 1 Id, which reduces stress concentrations in the most fragile part of the blade 7. This distributes the transmitted forces and limits the stress in these vulnerable areas of the blade root 11, and therefore reduces the risk of breakage of the blade root 11.

[0044] Furthermore, in order to increase the volume of forces that can be transmitted by the bases 14, 15, the second support 14b, 15b of each of the bases 14, 15 is mounted on the second portion 11b of the blade foot 11 so as to extend as far as possible from the junction 11d. The second support 14b, 15b thus extends at a distance from the first portion 11a and from the junction 11d. More precisely, these second supports 14b, 15b are fixed to the foot of blade 11 in areas of the second portion 11b positioned radially at a distance from junction 1 Id.

[0045] Similarly, to further protect the junction 1 Id, the first supports 14a, 15a of each of the bases 14, 15 can be fixed to the fastener 8a, if necessary via the first portion 1la so as to extend as far as possible from the junction 1 Id (taking into account the constraints of integrating the fastener 8a into the blade 6). The first support 14a, 15a thus extends at a distance, in a tangential direction, from the junction 1 Id. In this way, the transmission of forces between the two portions lia and 11b of the blade root 11 via the junction 1 Id, which is at high risk of breakage, is limited. It will be understood here that fixing the first supports 14a, 15a directly onto the hub 8 (via the attachment 8a) allows these first supports 14a, 15a to be moved further away from the junction 1 Id; however, the size of the second embodiment, where the first supports 14a, 15a are fixed onto the first portion 1 la of the blade foot 11 is smaller.

[0046] In one embodiment, each of the supports 14a, 14b, 15a, 15b of the bases 14, 15 includes a fixing plate 17a, 17b. Where applicable, the supports 14a, 14b, 15a, 15b may further include a reinforcing rib 18 configured to stiffen the bases 14, 15 and limit their deformation during the transmission of forces to the hub 8 (via the attachment 8a). Each reinforcing rib 18 then connects the connecting flange 14c, 15c to the fixing plate 17 of the base supports 14, 15. More specifically, each of the first supports 14a, 15a can include a first reinforcing rib 18a connecting the connecting flange 14c, 15c to the fixing plate 17a, and each of the second supports 4b, 15b can include a second reinforcing rib 18b connecting the connecting flange 14c, 15c to the fixing plate 17b.

[0047] The mounting plate 17a of each of the first supports 14a, 15a conforms to the external surface 8b of the fastener 8a. The first support 14a, 15a is secured to the hub 8 (via the fastener 8a) directly or via the first portion 1la by means of fasteners 19 such as bolts, screws, or any other equivalent means. In particular, in the embodiment in which the first supports 14a, 15a are fixed to the hub 8 (via the fastener 8a) by means of the first portion 1la of the blade foot 11, the fasteners 19 of the supports can be shared with the fasteners 13 of the first portion 1la of the foot 11 to the hub 8 (via the fastener 8a), in order to reduce the number of parts. Thus, the fixing plate 17a is positioned directly on the hub 8 (via the attachment 8a) or on the first portion lia.

[0048] On the other hand, the fixing plate 17b of each of the second supports 14b, 15b fits the opposite face of the second portion 11b of the blade foot 11. The fixing of the second support 14b, 15b to the second portion 11b of the foot of the blade 11 is made using the fixing devices 16.

[0049] In one embodiment (not shown in the figures), each of the supports 14a, 14b, 15a, 15b has at least one chamfered free edge in order to gradually transmit the forces to the blade 7 and the hub 8 (via the attachment 8a) and thus avoid creating stress ruptures. For example, each of the tangential free edges of the first supports 14a, 15a and the radial free edges of the second supports 14b, 15b are chamfered. By chamfered, it is understood that the thickness of the free edge is gradually reduced towards its free end 11. The free end 11 of the free edge is therefore thinner.

[0050] In the first embodiment (see for example [Fig. 2A]), the mounting plate 17a of the first supports 14a, 15a is fixed in a tangentially distant area from the blade foot 11, in order to transmit more forces to the hub 8 (via the attachment 8a). Thus, the first support 14a, 15a is mounted on the attachment 8a tangentially at a distance from the first portion 1a of the blade foot 11.

[0051] In the second embodiment (see, for example, [Fig. 2B]), the first support 14a, 15a is mounted on the first portion 1la such that the free edge of this first support 14a, 15a, which is closest to the Y-axis, extends at a distance from the junction 1Id. For this reason, the opposite free edge, i.e., the free edge of the first support 14a, 15a, which is furthest from the Y-axis of the blade, is closer to the free end 1le of the first portion 1la of the blade foot 11 than to the junction 1Id. In one embodiment, the opposite free edge can be positioned directly opposite the free end 1le of the first portion 1la. Thus, the distance between the first support 14a, 15a and the junction 1 Id of the blade foot 11 is the greatest possible, which increases the second moment of area as well as the recovery of forces from the blade 7.This embodiment also makes it possible to reduce the tangential bulk of the blade foot fixing 11 compared with the first embodiment.

[0052] Finally, the blade 7 includes a platform 20 configured to delimit a flow channel passing through the blade 7. The platform 20 comprises a radially external portion 20a mounted on all or part of the first supports 14a, 15a and a radially internal portion 20b mounted on the second portion 11b of the blade root 11. In one embodiment, the platform 20 comprises only a radially external portion 20a, extending on either side of the second portion 11b. Alternatively, the platform 20 may comprise a first radially external portion 20a fixed to the lower surface 7a of the blade 7 and a second radially external portion 20a fixed to the upper surface 7b of the blade. Similarly, the platform may include a single radially internal part 20b, which is fixed to one of the first and second bases 14, 15, so as to optimize the stress distribution and play on the stiffness of the platform for frequency positioning where applicable. Alternatively, the platform may comprise a first radially internal part 20b fixed to the first base 14 and a second radially internal part 20b fixed to the second base 15.

[0053] In a first embodiment, the platform 20 is brought and fixed on at least one of the bases 14, 15, preferably on each base 14, 15.

[0054] The radially external portion 20a is mounted on the second portion 11b of the blade 7 and comprises a flat surface 21 delimiting the flow channel and extending in a tangential direction. The flat surface 21 is therefore substantially parallel to the external surface 8b. The flat surface 21 is also located radially opposite the hub 8 with respect to the bases 14, 15. In one embodiment, the radially external portion 20a further comprises at least one fastening tab 22 configured to fix the radially external portion 20a to the second portion 11b of the blade root. For example, the fastening tab 22 may extend radially from an inner face of the flat surface 21 or form a radially bent end inside the flat surface 21. The fastening tab 22 extends along the chord of the blade 7.

[0055] In one embodiment, the fastening tab 22 is in contact with the second support 14b, 15b of the corresponding base 14, 15. Thus, it is possible to use the fastening members 16 to fix both the base 14, 15 and the platform 20 to the second portion 11b of the blade root 11. When the blade 7 comprises several bases 14, 15, the platform 20 may include a fastening tab 22 for each base 14, 15, in order to stiffen the platform 20. Alternatively, the platform 20 may include fastening tabs 22 only at the bases 14, 15 located near the leading and trailing edges of the blade 7.

[0056] In one embodiment, in particular the flat surface 21 is further in contact with the second portion 11b so as to limit leakage or air entry from the flow vein to the first portion 1 of the blade foot 11. A seal can be disposed between an external radial end of the second supports 14b, 15b and the flat surface 21, so as to seal the vein and protect the second portion 11b.

[0057] The radially internal portion 20b is mounted on all or part of the first supports 14a, 15a, and includes at least one connecting flange 23 connecting the flat surface 21 and the first support 14a, 15a of the corresponding base 14, 15. In one embodiment, the radially internal portion 20b includes as many connecting flanges 23 as there are bases 14, 15 in order to stiffen the platform 20.

[0058] More specifically, the radial flange 23 comprises an external end fixed to the flat surface 21 and an internal end, opposite the external end and fixed to the first support 14a, 15a of the base 14, 15 by means of fastening members 24, which may include bolts. Where appropriate, the inner end may be at the reinforcing rib 18a of the first support 14a, 15a, in order to limit the risk of failure of the base 14, 15.

[0059] In one embodiment, the connecting flange 23 has reinforcing ribs 25 at their internal and external ends.

[0060] For example, the platform 20 is made of a plastic or metallic material, for example polyetheretherketone (PEEK), polyetherimide (PEI), aluminum alloy or composite material.

[0061] In a second embodiment, the platform 20 is monolithic with at least one of the bases 14, 15.

[0062] The invention thus makes it possible to reduce the tangential and radial bulk at the base of the blade, while preserving the integrity of the base of the blade by ensuring the transfer of forces between the blade and the hub.

Claims

Demands

1. Blade (7) of a static blade (6) of a turbomachine, comprising: - a blade foot (11) comprising a first portion (lia) configured to be fixed on a hub (8) of the turbomachine and a second portion (11b) extending radially from the first portion (lia) with respect to an extension axis (X) of the blade (6);- a first and a second base (14, 15) extending on either side of the second portion (11b) and configured to transmit forces between the blade (7) and the hub (8), the first and second base (14, 15) each comprising a first support (14a, 15a) configured to be mounted on one of the first portion (1a) of the blade foot (11) at a distance from the second portion (11b) and the hub (8), a second support (14b, 15b) configured to be mounted on the second portion (11b) of the blade foot (11) at a distance from the first portion (1a) and the first support (14a, 15a), and a connecting flange (14c) connecting the first support (14a, 15a) and the second support (14b, 15b); and - a platform (20) comprising a radially internal part (20b) mounted on all or part of the first supports (14a, 15a) and a radially external part (20a) mounted on the second portion (11b) of the blade (7).;

2. Blade (7) according to claim 1, wherein the first and second portions (1a, 11b) of the blade foot (11) are connected by a junction (1Id) having a radius of curvature (R), the second support (14b, 15b) of the first base (14) and of the second base (15) being fixed to the blade foot (11) in an area of ​​the second portion (11b) positioned radially at a distance from the junction (1Id), and the first support (14a, 15a) of the first base (14) and of the second base (15) being fixed to the first portion (1a) or to the hub (8) in an area at a distance tangentially from the junction (1Id).

3. Blade (7) according to claim 2, wherein the first support (14a, 15a) of the first and second base (14, 15) is mounted on the first portion (1la) of the blade foot (11) such that a free edge of the first support (14a, 15a) is closer to a free end (1le) of the first portion (lia) of the blade foot (11) than to the junction (1Id).

4. Blade (7) according to any one of claims 1 to 3, wherein the first support (14a, 15a) of the first and second base (14, 15) is mounted on the hub (8), at a distance from the first portion (lia) of the paddle foot (11).

5. Blade (7) according to any one of claims 1 to 4, comprising several first bases (14) and several second bases (15), for example at least two and at most four first and second bases (14, 15), the first and second bases (14, 15) extending along the blade (7) between a leading edge and a trailing edge of the blade (7).

6. Blade (7) according to any one of claims 1 to 5, comprising first fixing members (13) configured to fix the first supports (14a, 15a) to the hub (8), and second fixing members (16) configured to fix the second supports (14b, 15b) to the second portion (11b) of the blade foot (11).

7. Blade (7) according to any one of claims 1 to 6, wherein the first and second supports (14a, 15a, 14b, 15b) each have a free edge, all or part of the free edges of the first and second supports (14a, 15a, 14b, 15b) being chamfered.

8. Blade (7) according to any one of claims 1 to 7, wherein the platform (20) is either monolithic with at least one of the first and second bases (14, 15), or attached and fixed to at least one of the first and second bases (14, 15) by means of third fixing members (24).

9. Blade (6) of a turbomachine comprising at least one blade (7) according to any one of claims 1 to 8 and a hub (8), the blade (7) being mounted in the hub (8) by means of first fastening members (13).

10. Blade (6) according to claim 9, wherein the blade (7) is mounted in the hub (8) by means of a fastener (8a), the fastener (8a) being pivotally mounted relative to the hub (8) about a radial shimming axis (Y).

Images