VARIABLE TIMING TURBOMACHINE BLADE.

Abstract

The present invention relates to a variable-pitch turbine blade (1) for an aircraft turbomachine, comprising a blade (2) extending at the blade tip (21) by an external plate (3a) and then an external pivot (4a), and at the blade root (22) by an internal plate (3b) and then an internal pivot (4b). This blade (2) has a leading edge (23) and a trailing edge (24) and is capable of pivoting about an axis of rotation (X-X') joining the center of the external pivot (4a) to the center of the internal pivot (4b). This blade is notable in that it comprises a functional part (5) and a wear part (6b), assembled together. The wear part is located either at the blade root and near the leading edge or trailing edge, respectively, or at the blade tip and near the leading edge or trailing edge, respectively. Figure for the abstract: Fig. 4.

Description

Title of the invention: VARIABLE PITCHING BLADE FOR TURBO MACHINE. FIELD OF THE INVENTION

[0001] The invention is in the field of aeronautics.

[0002] The present invention relates more particularly to a variable-pitch vane for an aircraft turbomachine rectifier and in particular for a compressor rectifier, more preferably for a high-pressure compressor.

[0003] The invention also relates to an aircraft turbomachine, provided with a rectifier equipped with at least one such variable-pitch blade. STATE OF THE ART

[0004] As can be seen in the attached [Fig.l], the variable-pitch blades (known under the English name of "variable stator vary or VSV") can be maneuvered so as to pivot around an axis of rotation X-X'. This makes it possible to modify their angle of incidence (or pitch angle) relative to the air flow coming from upstream of the turbomachine (on the left in [Fig.l]) and this, during the different phases of flight.

[0005] Each variable-pitch blade A comprises a blade B and at each end thereof, successively a plate C and a pivot D, the axis of rotation X-X' being centered on the pivots D.

[0006] During their use, variable pitch blades are subjected to very high stresses, particularly in terms of pressure, temperature and mechanical stresses.

[0007] In the attached figures 2 and 3, we can see for each blade A, two critical zones at the level of which the stresses are concentrated more particularly. Incipient cracks E appear first of all at the level of the connection fillet between the blade B and the plate C, (mainly on the side of the trailing edge). Then, these incipient cracks propagate to form cracks F and lead to the complete rupture of the blade A.

[0008] A variable-pitch blade is already known from document FR 3 014 964. More precisely, this blade comprises, on the one hand, a blade and four internal pivot elements, made of composite material, and on the other hand, two metal caps.

[0009] The blade is provided at each of its two ends with shoulders and a lug and two internal pivot elements are fixed on either side of each lug, so as to define the plate and the pivot of the blade. In addition, each cap covers this plate and this pivot.

[0010] However, such a dawn does not allow for effective resolution of the problems of formation of the aforementioned crack initiations and, moreover, it requires the manufacture and assembly of a large number of parts. Statement of the invention

[0011] The aim of the invention is to provide a variable-pitch blade which greatly limits the impact of a crack starting on the blade, by avoiding complete breakage of the blade and therefore of the blade, while retaining the functions of this blade which are to straighten the air flow coming from upstream and to be able to be oriented according to different pitch angles.

[0012] To this end, the invention relates to a variable-pitch vane for an aircraft turbomachine rectifier, comprising a blade extending at the blade head by an external plate then an external pivot and at the blade root by an internal plate then an internal pivot, this blade having a leading edge and a trailing edge and being able to pivot around an axis of rotation joining the center of the external pivot to the center of the internal pivot.

[0013] According to the invention, this blade is made up of a functional part and a wear part, assembled together, this wear part being:

[0014] - either a wear part which comprises a first part of the blade head which extends transversely from the trailing edge at most to the axis of rotation of the blade and which is extended by a first part of the external plate which extends transversely from a downstream zone of the circumferential contour of this external plate at most to the axis of rotation of the blade, so that this first part of the blade head and this first part of the external plate form a single-piece assembly which encompasses the connection line between the blade head and the downstream zone of the external plate, - either a wear part which comprises a first part of the blade root which extends transversely from the trailing edge at most to the axis of rotation of the blade and which is extended by a first part of the internal plate which extends transversely from a downstream zone of the circumferential contour of this internal plate at most to the axis of rotation of the blade, so that this first part of the blade root and this first part of the internal plate form a single-piece assembly which encompasses the connection line between the blade root and the downstream zone of the internal plate,

[0015] - either a wear part which comprises a second part of the blade head which extends transversely from the leading edge at most to the axis of rotation of the blade and which is extended by a second part of the external plate which extends transversely from an upstream zone of the circumferential contour of this external plate at most to the axis of rotation of the blade, so that this second part of the blade head and this second part of the external plate form a single-piece assembly which encompasses the connection line between the blade head and the upstream zone of the external plate,

[0016] - either a wear part which comprises a second part of the blade root which extends transversely from the leading edge at most to the axis of rotation of the blade and which is extended by a second part of the internal plate which extends transversely from an upstream zone of the circumferential contour of this internal plate at most to the axis of rotation of the blade, so that this second part of the blade root and this second part of the internal plate form a single-piece assembly which encompasses the connection line between the blade root and the upstream zone of the internal plate,

[0017] and in that the functional part is made up of the remainder of the blade.

[0018] Thanks to these characteristics of the invention, the functional part and the wear part being separate, a crack initiation in the wear part is not transmitted to the functional part. In the event of damage to this wear part, only this one needs to be replaced. This solution is therefore more economical.

[0019] Preferably, the wear part is:

[0020] - either a wear part which comprises a first part of the blade head which extends transversely from the trailing edge at most to the axis of rotation of the blade and which is extended by a first part of the external plate which extends transversely from a downstream zone of the circumferential contour of this external plate at most to the axis of rotation of the blade then by a first part of the external pivot which extends from the downstream zone of the circumferential contour of this external pivot at most to the axis of rotation of the blade, so that this first part of the blade head, this first part of the external plate and this first part of the external pivot form a single-piece assembly which encompasses the connection line between the blade head and the downstream zone of the external plate,

[0021] - either a wear part which comprises a first part of the blade root which extends transversely from the trailing edge at most to the axis of rotation of the blade and which is extended by a first part of the internal plate which extends transversely from a downstream zone of the circumferential contour of this internal plate at most to the axis of rotation of the blade then by a first part of the internal pivot which extends from the downstream zone of the circumferential contour of this internal pivot at most to the axis of rotation of the blade, so that this first part of the blade root, this first part of the internal plate and this first part of the internal pivot form a single-piece assembly which encompasses the connection line between the blade root and the downstream zone of the internal plate,

[0022] - either a wear part which comprises a second part of the blade head which extends transversely from the leading edge at most to the axis of rotation of the blade and which is extended by a second part of the external plate which extends transversely from an upstream zone of the circumferential contour of this external plate at most to the axis of rotation of the blade then by a second part of the external pivot which extends from the upstream zone of the circumferential contour of this external pivot at most to the axis of rotation of the blade, so that this second part of the blade head, this second part of the external plate and this second part of the external pivot form a single-piece assembly which encompasses the connection line between the blade head and the upstream zone of the external plate,

[0023] - either a wear part which comprises a second part of the blade root which extends transversely from the leading edge at most to the axis of rotation of the blade and which is extended by a second part of the internal plate which extends transversely from an upstream zone of the circumferential contour of this internal plate at most to the axis of rotation of the blade then by a second part of the internal pivot which extends from the upstream zone of the circumferential contour of this internal pivot at most to the axis of rotation of the blade, so that this second part of the blade root, this second part of the internal plate and this second part of the internal pivot form a single-piece assembly which encompasses the connection line between the blade root and the upstream zone of the internal plate.

[0024] According to other advantageous and non-limiting characteristics of the invention, taken alone or in combination:

[0025] - the height of the first part of the blade head or the height of the second part of the blade head included in the wear part and measured from the blade head or the height of the first part of the blade root or the height of the second part of the blade root included in the wear part and measured from the blade root measures up to 20% of the height of the blade measured along the axis of rotation.

[0026] - the first part or the second part of the internal plate has, in a plane of section perpendicular to the axis of rotation of the blade, the shape of an angular section which is symmetrical with respect to a first straight line, this first straight line is perpendicular to the axis of rotation of the blade and passes through this axis of rotation of the blade and a point located in the middle of the connection line between the blade root and the downstream zone of the internal plate, and in that the angle of this angular section is equal to twice an angle, measured from said first straight line and between 30° and 90°.

[0027] - the first part or the second part of the external plate has, in a plane of section perpendicular to the axis of rotation of the blade, the shape of an angular section which is symmetrical with respect to a third straight line, this third straight line is perpendicular to the axis of rotation of the blade and passes through this axis of rotation of the blade and a point located in the middle of the connection line between the blade head and the downstream zone of the external plate and the angle of this angular section is equal to twice an angle, measured from said third straight line and between 30° and 90°.

[0028] - the first part or the second part of the internal pivot presents, in a plane of section perpendicular to the axis of rotation of the blade, the shape of an angular section which is symmetrical with respect to a second straight line, this second straight line is perpendicular to the axis of rotation of the blade, passes through this axis of rotation of the blade and is in the same plane as the first straight line and the angle of this angular section is equal to twice an angle measured from said second straight line and between 30° and 90°.

[0029] - the first part or the second part of the external pivot presents, in a plane of section perpendicular to the axis of rotation of the blade, the shape of an angular section which is symmetrical with respect to a fourth straight line, this fourth straight line is perpendicular to the axis of rotation of the blade, passes through this axis of rotation of the blade and is in the same plane as the third straight line and the angle of this angular section is equal to twice an angle measured from said fourth straight line and between 30° and 90°.

[0030] - the wear part and the functional part are made of metal.

[0031] - the functional part is made of metal and the wear part is made of composite material.

[0032] - the wear part and the functional part are assembled by welding.

[0033] - the wear part and the functional part are assembled by gluing.

[0034] - the wear part and the functional part are assembled by interlocking mechanics of the wear part into the functional part.

[0035] The invention also relates to an aircraft turbomachine equipped with a rectifier.

[0036] According to the invention, said rectifier comprises at least one variable-pitch blade as mentioned above. DESCRIPTION OF FIGURES

[0037] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0038] [Fig.l] is a side view showing the structure of a variable pitch blade.

[0039] [Fig.2] is a diagram showing the beginning of damage to a blade.

[0040] [Fig.3] is a diagram showing the sequence of damage to a blade.

[0041] [Fig.4] is a side view showing the structure of a variable pitch vane in accordance with the invention.

[0042] [Fig.5] is a cross-sectional view of the blade of [Fig.4], taken along the section plane passing through line VV in [Fig.4].

[0043] [Fig.6] is a cross-sectional view of the blade of [Fig.4], taken along the section plane passing through line VI-VI in [Fig.4].

[0044] [Fig.7] is a side view of a first variant embodiment of the blade of the [Fig.4],

[0045] [Fig.8] is a cross-sectional view of the blade of [Fig.7], taken along the section plane passing through line VIII-VIII in [Fig.7].

[0046] [Fig.9] is a side view of a second variant embodiment of the blade of the [Fig.4],

[0047] [Fig. 10] is a side view of a third alternative embodiment of the blade of [Fig.4],

[0048] [Fig. 11] is a cross-sectional view of the blade of [Fig. 10], taken along the section plane passing through line XI-XI in [Fig. 10].

[0049] [Fig. 12] is a side view of a fourth alternative embodiment of the blade of [Fig.4],

[0050] [Fig. 13] is a cross-sectional view of the blade of [Fig.9], taken along the section plane passing through line VV in [Fig.9].

[0051] [Fig. 14] is a diagram showing the start of damage to a blade according to the invention.

[0052] [Fig. 15] is a diagram showing the stopping of damage to a blade according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0053] A first embodiment of a variable-pitch blade according to the invention will now be described in connection with FIGS. 4 to 7.

[0054] In the remainder of the description and claims,

[0055] In [Fig.4], it can be seen that the variable-pitch blade 1 comprises a central part forming a blade 2, which extends at the blade head 21, successively by an external plate 3a then by an external pivot 4a and at the blade root 22, successively by an internal plate 3b then by an internal pivot 4b.

[0056] The terms "external" and "internal" are used in the remainder of the description and the claims to designate a radially external, respectively radially internal, part of the blade 1, relative to its normal position of use in the turbomachine.

[0057] The blade 1 can pivot around an axis of rotation X-X' joining the center of the external pivot 4a to the center of the internal pivot 4b, the rotation being ensured by a control member not visible in the figures.

[0058] Preferably, the pivots and the plates are cylindrical in shape.

[0059] Furthermore, each plate 3a, 3b has on its circumferential contour a zone upstream 31a, respectively 31b and a downstream zone 32a, respectively 32b, and likewise each pivot 4a, 4b has on its circumferential contour an upstream zone 41a, respectively 41b and a downstream zone 42a, respectively 42b (upstream and downstream being defined in the description and the claims with respect to the direction of air flow on the blade and more generally in the turbomachine, that is to say from left to right in the figures). Each zone extends at most over 180°.

[0060] The blade 2 has a leading edge 23 and a trailing edge 24.

[0061] According to the invention, the blade 1 is made up of a functional part 5 and a wear part which are assembled together, as will be described later.

[0062] In the first embodiment of the invention shown in Figures 4 to 6, the wear part bears the reference 6b.

[0063] Apart from the wear part 6b, the functional part 5 constitutes the remainder of the blade 1.

[0064] The functional part 5 forms the main portion of the blade 1 and retains the functional missions thereof, namely the aerodynamic function provided by a part of the blade and the plates and the rotation function of the blade provided by a part of the pivots.

[0065] The wear part 6b forms a portion of the blade 1 smaller than the functional part 5 and supports the maximum stresses. It can be replaced in the event of wear or breakage, thus avoiding the replacement of the complete blade 1.

[0066] The wear part 6b comprises a part (called "first part") 220 of the blade root 22 which extends transversely (i.e. in the direction of the axis of rotation X-X' of the blade) from its trailing edge 24 at most to this axis of rotation X-X' and which is extended (i.e. in the internal radial direction, i.e. downwards in [Fig. 4]) by a part (called "first part") 33b of the internal plate 3b.

[0067] This first part 33b extends transversely from the downstream zone 32b of the circumferential contour of this internal plate 3b, (which is therefore located on the trailing edge side of the blade) at most up to the axis of rotation X-X'.

[0068] Thus, this first part 220 of the blade root 22 and this first part 33b of internal plate 3b form a single-piece assembly, that is to say a single piece and of the same material, which constitutes the wear part 6b.

[0069] Furthermore, the single-piece wear part 6b is shaped so as to encompass the connection line 25 (or connection fillet) between the blade root 22 and the downstream zone 32b of the circumferential contour of the internal plate 3b. This connection line 25 can also be seen in dotted lines in [Fig. 5]. This connection line constitutes precisely a location subject to high stresses during use of the blade 1, (see the previous explanations given in connection with Figures 2 and 3).

[0070] As can be seen in [Fig. 4], the first part 220 of the blade root 22 which is part of the wear part 6b extends over a height H1 measured from the blade root 22 in the direction of the middle part 20 of the blade 2. Preferably, this height H1 is chosen so as not to impact the aerodynamic operation of the blade 2 and to maintain good mechanical strength, that is to say to encompass the high stress zone and to have an interface between the blade 2 and this first part 220 of a sufficient area to allow the fixing of this first part 220 on the blade 2.

[0071] Preferably, this height H1 measures up to 20% of the height H of the blade 2 measured along the axis of rotation X-X'.

[0072] As can be seen in [Fig.4], this height H1 is not necessarily constant over the entire part 220 and it can decrease when approaching transversely the axis X-X'.

[0073] As can be seen in [Fig.5], the first part 220 extends over a thickness E1 which is preferably equal to the entire thickness of the blade 2.

[0074] Furthermore, the first part 220 extends over a length L1 which at most extends from the trailing edge 24 to the axis X-X' as explained previously but which may be less as can be seen in FIGS. 4 and 5.

[0075] Furthermore, to the extent that the height H1 can vary, this length L1 can also vary over the height of the first part 220. In the figures, the length L1 is for example longer near the blade root.

[0076] As can be seen in Figures 4 and 6, the first part 33b of the internal plate 3b which is part of the wear part 6b extends over a height H2, measured along an axis parallel to the axis of rotation X-X', which corresponds at most to the total height of the internal plate 3b.

[0077] Furthermore, the first part 33b of the internal plate 3b extends over a length L2 which extends from the downstream zone 32b of the contour at most up to the axis X-X' as explained previously but which may be less as seen in Figures 4 and 6. In addition, this length L2 may vary over the height of the internal plate 3b. In the figures, it is for example shorter near the blade root 22 and longer near the pivot 4b.

[0078] Finally, the first part 33b of the internal plate 3b advantageously has, in a section plane perpendicular to the axis of rotation X-X', the shape of an angular section, (see [Fig.6]).

[0079] This angular section is symmetrical with respect to a first straight line Y-Y', perpendicular to the axis of rotation X-X' of the blade and which passes through this axis of rotation X-X' and through a midpoint 250 located in the middle of the connecting line 25 or a point located directly above this midpoint (see [Fig.5]). As can be seen in [Fig.6], the angle a of this angular section is equal to twice an angle al, this angle al being measured from the first line Y-Y' and this angle al being between 30° and 90°.

[0080] According to a variant of the first embodiment, shown in Figures 7 and 8, the wear part 6b may also include a part (called "first part") 43b of the internal pivot 4b which extends transversely over a length L3 from the downstream zone 42b of its circumferential contour at most up to the axis X-X'. This first part 43b extends over a height H3, which preferably corresponds to the entire height of said internal pivot 4b. The first part 43b is in one piece with the parts 220 and 33b.

[0081] Finally, the first part 43b of the internal pivot 4b advantageously has, in a section plane perpendicular to the axis of rotation X-X', the shape of an angular section, (see [Fig.8]).

[0082] This angular section is symmetrical with respect to a second straight line Yl-Y' 1. This second straight line Y1-Y' 1 is perpendicular to the axis of rotation X-X' of the blade, it passes through this axis of rotation X-X' and it is in the same plane as the first straight line Y-Y' mentioned above and is parallel to it. The angle a2 of this angular section is equal to twice an angle a3, this angle a3 being measured from the second straight line Y 1-Y' 1 and being between 30° and 90°.

[0083] It will be noted that the values ​​of the angles a1 and a3 can be identical or different from each other.

[0084] [Fig.9] illustrates a second embodiment of the invention, in which the wear part, referenced 6a, is formed at the trailing edge and at the blade tip.

[0085] In this case, the wear part 6a comprises a first portion 210 of the blade head 21 which extends from its trailing edge 24 transversely at most to the axis of rotation X-X' and which is extended (in the external radial direction, i.e. upwards in [Fig. 9]) by a first portion 33a of the external plate 3a which extends transversely from the downstream zone 32a of the circumferential contour of this external plate 3a at most to the axis of rotation X-X'. Optionally, the wear part 6a may also include a first portion 43a of the external pivot 4a.

[0086] Furthermore, the single-piece wear part 6a is shaped so as to encompass the connection line 26 between the blade head 21 and the downstream zone 32a of the external plate 3a.

[0087] In a similar manner to what has been described for the wear part 6b and which will not be described again in detail, the first part 210 has a length L4 measured from the trailing edge 24 and a height H4 measured from the blade head (preferably at most 20% of H), the first part 33a has a length L5 measured from the downstream zone 32a and a height H5 and finally the first part 43a has a length L6 and a height H6.

[0088] Similar to what has been described for the wear part 6b, in the wear part 6a, the angular section of the first part 33a of the external plate 3a, in a plane perpendicular to X-X', is symmetrical with respect to a third straight line Y2-Y'2. This straight line Y2-Y'2 passes through the axis X-X' and a point 260 located in the middle of the connecting line 26 or a point located directly above this point 260 (see figures 9 and 13). The angle a4 of this angular section is equal to twice an angle a5, measured from said third straight line Y2-Y'2 and the angle a5 is between 30° and 90°.

[0089] Similarly, the angular section of the first part 43a of the external pivot 4a, in a plane perpendicular to X-X', is symmetrical with respect to a fourth straight line Y3-Y'3. This straight line Y3-Y'3 is perpendicular to the axis X-X', passes through it and is in the same plane as the third straight line Y2-Y'2. The angle a6 of this angular section is equal to twice an angle a7, measured from said fourth straight line Y3-Y'3 and the angle a7 is between 30° and 90°.

[0090] [Fig. 10] illustrates a third embodiment of the invention, in which the wear part, referenced 7b, is formed at the leading edge and at the root of the blade.

[0091] In this case, the wear part 7b comprises a second portion 221 of the blade root 22 which extends from its leading edge 23 transversely at most to the axis of rotation X-X' and which is extended (in the internal radial direction, i.e. downwards in [Fig. 10]) by a second portion 34b of the internal plate 3b which extends transversely from the upstream zone 31b of the circumferential contour of this internal plate 3b and at most to the axis of rotation X-X'. Optionally, the wear part 7b may also include a second portion 44b of the internal pivot 4b.

[0092] Furthermore, the single-piece wear part 6a is shaped so as to encompass the connection line 28 between the blade root 22 and the upstream zone 31b of the internal plate 3b.

[0093] In a similar manner to what has been described for the wear part 6b and which will not be described again in detail, the second part 221 has a length L7 measured from the leading edge 23 and a height H7 measured from the blade root (preferably at most 20% of H), the second part 34b has a length L8 measured from the upstream zone 31b and a height H8 and finally the second part 44b has a length L9 and a height H9.

[0094] Finally, [Fig. 12] illustrates a fourth embodiment of the invention, in which the wear part, referenced 7a, is formed at the leading edge and at the blade tip.

[0095] In this case, the wear part 7a comprises a second part 211 of the blade head 21 which extends from its leading edge 23 transversely at most to the axis of rotation X-X' and which is extended (in the external radial direction, i.e. upwards in [Fig. 12]) by a second part 34a of the external plate 3a which extends transversely from the upstream zone 31a of the circumferential contour of this external plate 3a and at most to the axis of rotation X-X'. In an op tional, the wear part 7a may also include a second part 44a of the external pivot 4a.

[0096] Furthermore, the single-piece wear part 7a is shaped so as to encompass the connection line 27 between the blade head 21 and the upstream zone 31a of the external plate 3a.

[0097] In a similar manner to what has been described for the wear part 6b and which will not be described again in detail, the second part 211 has a length L10 measured from the leading edge 23 and a height H10 measured from the blade head (preferably at most 20% of H), the second part 34a has a length L11 measured from the upstream zone 31a and a height H11 (at most equal to the height of the plate 3a) and finally the second part 44a has a length L12 and a height H12.

[0098] What has been specified for the lengths L1, L2 and L3 and for the heights H1, H2 and H3 of the wear part 6b also applies respectively to the lengths L4 to L12 and the heights H4 to H12 of the parts 6a, 7b and 7a.

[0099] Furthermore, the thickness of the first part 210 and of the second parts 211 and 221 is preferably equal to the entire thickness of the blade 2.

[0100] Finally, what has been specified for the angles a1 and a3 of part 6b and a5 and a7 of part 6a also applies to the wear parts 7a and 7b.

[0101] Whatever the embodiment of the wear part 6a, 6b, 7a or 7b as previously described, the fact that it is distinct from the functional part 5 and that it includes the connection line 26, 25, 27 or respectively 28 means that when a crack initiation E appears at the level of this connection line (for example the line 25 in [Fig. 14]), and that this initiation transforms into a crack F, then this crack is stopped at the level of the boundary 8 between the wear part and the functional part, (see [Fig. 15]).

[0102] The dissociation of the functional part 5 and the wear part 6a, 6b, 7a or 7b thus makes it possible to stop the propagation of a possible crack in the direction of the functional part 5 and to only have to replace the wear part. In addition, a complete breakage of the blade 1 is avoided. Materials and manufacturing processes.

[0103] The functional part 5 and the wear part 6a, 6b, 7a or 7b may both be made of metal, for example the same metal or made of different materials. Thus, for example, the functional part 5 may be made of metal and the wear part 6a, 6b, 7a or 7b of composite material (fibers and resin).

[0104] The manufacturing of metal parts can be done, for example, by machining, by additive manufacturing or by casting. The manufacturing of the composite material part can be done by weaving the fibers then adding the resin and hardening. Assembly of the parts.

[0105] This assembly can be carried out by welding when the functional part 5 and the wear part are both made of metal. The functional part and the wear part having complementary shapes, this welding is carried out at the border between the two and in particular at the junction of the wear part with the plate part 3a or 3b of the functional part 5.

[0106] This assembly can be carried out by gluing in the case of metal and composite bi-materials, this gluing preferably being carried out at the junction of the wear part with the plate part 3a or 3b of the functional part 5.

[0107] Finally, this assembly can be carried out by mechanical assembly of the parts.

[0108] For example, the functional part 5 and the wear part 6a, 6b, 7a, 7b can be nested one inside the other and held together by the bore of the rectifier housing in which the pivot and the plate are inserted. It is also possible to provide one or more projecting pins on one of the two parts and one or more holes for receiving these pins on the other of the two parts.

[0109] The variable-pitch vane 1 which has just been described can be used in any rectifier of a turbomachine, in particular in a rectifier of a compressor, more particularly a high-pressure compressor.

Claims

Claims

1. Variable-pitch vane (1) for an aircraft turbomachine rectifier, comprising a blade (2) extending at the blade head (21) by an external plate (3a) then an external pivot (4a) and at the blade root (22) by an internal plate (3b) then an internal pivot (4b), this blade (2) having a leading edge (23) and a trailing edge (24) and being able to pivot about an axis of rotation (X-X') joining the center of the external pivot (4a) to the center of the internal pivot (4b), characterized in that it consists of a functional part (5) and a wear part (6a, 6b, 7a, 7b), assembled together, this wear part being: - either a wear part (6a) which comprises a first part (210) of the blade head (21) which extends transversely from the trailing edge (24) at most to the axis of rotation (X-X') of the blade and which is extended by a first part (33a) of the external plate (3a) which extends transversely from a downstream zone (32a) of the circumferential contour of this external plate (3a) at most to the axis of rotation (X-X') of the blade, so that this first part (210) of the blade head and this first part (33a) of the external plate form a single-piece assembly which encompasses the connection line (26) between the blade head (21) and the downstream zone (32a) of the external plate (3a),- either a wear part (6b) which comprises a first part (220) of the blade root (22) which extends transversely from the trailing edge (24) at most to the axis of rotation (X-X') of the blade and which is extended by a first part (33b) of the internal plate (3b) which extends transversely from a downstream zone (32b) of the circumferential contour of this internal plate (3b) at most to the axis of rotation (X-X') of the blade, so that this first part (220) of the blade root and this first part (33b) of the internal plate form a single-piece assembly which encompasses the connection line (25) between the blade root (22) and the downstream zone (32b) of the internal plate (3b),- either a wear part (7a) which comprises a second part (211) of the blade head (21) which extends transversely from the leading edge (23) at most to the axis of rotation (X-X') of the blade and which is extended by a second part (34a) of the external plate (3a) which extends transversely from an upstream zone (31a) of the circumferential contour of this external plate (3a) at most to the axis of,

2. rotation (X-X') of the blade, so that this second part (211) of the blade head and this second part (34a) of the external plate form a single-piece assembly which includes the connection line (27) between the blade head (21) and the upstream zone (31a) of the external plate (3a), - or a wear part (7b) which comprises a second part (221) of the blade root (22) which extends transversely from the leading edge (23) at most to the axis of rotation (X-X') of the blade and which is extended by a second part (34b) of the internal plate (3b) which extends transversely from an upstream zone (31b) of the circumferential contour of this internal plate (3b) at most to the axis of rotation (X-X') of the blade, so that this second part (221) of the blade root and this second part (34b) of the internal plate form a single-piece assembly which includes the connection line (28) between the blade root (22) and the upstream zone (31b) of the internal plate (3b),and in that the functional part (5) is made up of the remainder of the blade (1)., Variable pitch vane according to claim 1, characterized in that the wear part is: - either a wear part (6a) which comprises a first part (210) of the blade head (21) which extends transversely from the trailing edge (24) at most to the axis of rotation (X-X') of the blade and which is extended by a first part (33a) of the external plate (3a) which extends transversely from a downstream zone (32a) of the circumferential contour of this external plate (3a) at most to the axis of rotation (X-X') of the blade then by a first part (43a) of the external pivot (4a) which extends from the downstream zone (42a) of the circumferential contour of this external pivot at most to the axis of rotation (X-X') of the blade, so that this first part (210) of the blade head, this first part (33a) of the external plate and this first part (43a) of the external pivot form a single-piece assembly which includes the connection line (26) between the blade head (21) and the downstream zone (32a) of the external plate (3a), - either a wear part (6b) which comprises a first part (220) of the blade root (22) which extends transversely from the trailing edge (24) at most to the axis of rotation (X-X') of the blade and which is extended by a first part (33b) of the internal plate (3b) which extends transversely from a downstream zone (32b) of the circumferential contour of this internal plate (3b) at most to the axis of

3. rotation (X-X') of the blade then by a first part (43b) of the internal pivot (4b) which extends from the downstream zone (42b) of the circumferential contour of this internal pivot at most to the axis of rotation (X-X') of the blade, so that this first part (220) of the blade root, this first part (33b) of the internal plate and this first part (43b) of the internal pivot form a single-piece assembly which includes the connection line (25) between the blade root (22) and the downstream zone (32b) of the internal plate (3b), - either a wear part (7a) which comprises a second part (211) of the blade head (21) which extends transversely from the leading edge (23) at most to the axis of rotation (X-X') of the blade and which is extended by a second part (34a) of the external plate (3a) which extends transversely from an upstream zone (31a) of the circumferential contour of this external plate (3a) at most to the axis of rotation (X-X') of the blade then by a second part (44a) of the external pivot (4a) which extends from the upstream zone (41a) of the circumferential contour of this external pivot at most to the axis of rotation (X-X') of the blade, so that this second part (211) of the blade head, this second part (34a) of the external plate and this second part (44a) of the external pivot form a single-piece assembly which includes the connection line (27) between the blade head (21) and the upstream zone (31a) of the external plate (3a), - either a wear part (7b) which comprises a second part (221) of the blade root (22) which extends transversely from the leading edge (23) at most to the axis of rotation (X-X') of the blade and which is extended by a second part (34b) of the internal plate (3b) which extends transversely from an upstream zone (31b) of the circumferential contour of this internal plate (3b) at most to the axis of rotation (X-X') of the blade then by a second part (44b) of the internal pivot (4b) which extends from the upstream zone (41b) of the circumferential contour of this internal pivot at most to the axis of rotation (X-X') of the blade, so that this second part (221) of the blade root, this second part (34b) of the internal plate and this second part (44b) of the internal pivot form a single-piece assembly which includes the connection line (28) between the blade root (22) and the upstream zone (31b) of the internal plate (3b). Variable pitch blade according to claim 1 or 2, characterized in that the height (H4) of the first part (210) of the blade head (21) or the height (H 10) of the second part (211) of the blade head (21) included in the wear part (6a, 7a) and measured from the blade head (21) or the height (Hl) of the first part (220) of the blade root (22) or the height (H7) of the second part (221) of the blade root (22) included in the wear part (6b, 7b) and measured from the blade root (22) measures up to 20% of the height (H) of the blade (2) measured along the axis of rotation (X-X').

4. Variable-pitch blade according to any one of the preceding claims, characterized in that the first part (33b) or the second part (34b) of the internal plate (3b) has, in a section plane perpendicular to the axis of rotation (X-X') of the blade, the shape of an angular section which is symmetrical with respect to a first straight line (Y-Y'), in that this first straight line (Y-Y') is perpendicular to the axis of rotation (X-X') of the blade and passes through this axis of rotation (X-X') of the blade and a point (250) located in the middle of the connection line (25) between the blade root (22) and the downstream zone (32b) of the internal plate (3b), and in that the angle (a) of this angular section is equal to twice an angle (al), measured from said first straight line (Y-Y') and between 30° and 90°.

5. Variable-pitch blade according to any one of the preceding claims, characterized in that the first part (33a) or the second part (34a) of the external plate (3a) has, in a section plane perpendicular to the axis of rotation (X-X') of the blade, the shape of an angular section which is symmetrical with respect to a third straight line (Y2-Y'2), in that this third straight line (Y2-Y'2) is perpendicular to the axis of rotation (X-X') of the blade and passes through this axis of rotation (X-X') of the blade and a point (260) located in the middle of the connection line (26) between the blade head (21) and the downstream zone (32a) of the external plate (3a), and in that the angle (a4) of this angular section is equal to twice an angle (a5), measured from said third straight line (Y2-Y'2) and between 30° and 90°.

6. Variable-pitch blade according to claims 2 and 4, characterized in that the first part (43b) or the second part (44b) of the internal pivot (4b) has, in a section plane perpendicular to the axis of rotation (X-X') of the blade, the shape of an angular section which is symmetrical with respect to a second straight line (Y 1-Y' 1), in that this second straight line (Y 1-Y' 1) is perpendicular to the axis of rotation (X-X') of the blade, passes through this axis of rotation (X-X') of the blade and is in the same plane as the first straight line (Y-Y'), and in that the angle (a2) of this angular section is equal to twice an angle (a3) ​​measured from said second straight line (Y 1-Y' 1) and between 30° and 90°.

7. Variable pitch vane according to claims 2 and 5, characterized in that the first part (43a) or the second part (44a) of the external pivot (4a) has, in a section plane perpendicular to the axis of rotation (X-X') of the vane, the shape of an angular section which is symmetrical with respect to a fourth straight line (Y3-Y'3), in that this fourth straight line (Y3-Y'3) is perpendicular to the axis of rotation (X-X') of the vane, passes through this axis of rotation (X-X') of the vane and is in the same plane as the third straight line (Y2-Y2'), and in that the angle (a6) of this angular section is equal to twice an angle (a7) measured from said fourth straight line (Y3-Y'3) and between 30° and 90°.

8. Variable pitch vane according to any one of the preceding claims, characterized in that the wear part (6a, 7a, 6b, 7b) and the functional part (5) are made of metal.

9. Variable pitch vane according to any one of claims 1 to 7, characterized in that the functional part (5) is made of metal and the wear part (6a, 7a, 6b, 7b) is made of composite material.

10. Variable pitch vane according to claim 8, characterized in that the wear part (6a, 7a, 6b, 7b) and the functional part (5) are assembled by welding.

11. Variable pitch vane according to claim 9, characterized in that the wear part (6a, 7a, 6b, 7b) and the functional part (5) are assembled by gluing.

12. Variable pitch vane according to any one of claims 1 to 9, characterized in that the wear part (6a, 7a, 6b, 7b) and the functional part (5) are assembled by mechanical fitting of the wear part (6a, 7a, 6b, 7b) into the functional part (5).

13. Aircraft turbomachine provided with a rectifier, characterized in that said rectifier comprises at least one variable-pitch blade (1) according to any one of the preceding claims.

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