Device for setting a blade root in a fan and method for adjusting a clearance between the blade and an associated casing

Abstract

The present invention relates to a device (30a; 30b) for wedging a blade root (9) in a cell (12) of a rotor disk (11) of a turbomachine (1), comprising a first wedging portion intended to bear against a lateral surface of the blade root (9), a second wedging portion intended to bear against a lower surface of the blade root (9), and a connecting portion connecting the first wedging portion to the second wedging portion and intended to bear against a wall of the cell (12). Figure for abstract: Fig. 2

Description

Title of the invention: Device for setting a blade root in a fan and method for adjusting a clearance between the blade and an associated casing Technical field

[0001] The present invention relates to the field of turbomachines, in particular the field of shrouded fan rotors, even if it finds applications and benefits applicable to non-shrouded rotors, in particular for aircraft.

[0002] The present invention relates more particularly to a device for wedging a blade root in a cell of a fan rotor. STATE OF THE ART

[0003] On a turbomachine, in particular a bypass turbojet, a fan is arranged upstream of the low-pressure compressor relative to the direction of air flow in the turbomachine. Its role is to ensure the initial compression of the air entering the turbomachine. Such a fan generally comprises a plurality of blades extending radially relative to an extension axis (also referred to as the axis of rotation) of the turbomachine, from a fan rotor. More particularly, each of the blades comprises at its base a blade root secured to the rotor of the fan.

[0004] Conventionally, the attachment of the root of a blade to the fan rotor is done by means of a dovetail assembly, or broached attachment, between the blade root and a cell formed in the fan rotor, in particular on its periphery.

[0005] However, conventionally, the cell is machined with dimensions greater than those of the blade root, in order to be able to easily insert the blade root into said cell, this insertion being particularly carried out by sliding along a longitudinal axis parallel to the extension axis.

[0006] Due to these differences in dimensions, there is a clearance between the blade root and the walls of the cell, so that during rotation of the fan and therefore of the blade around the extension axis, the blade root may be damaged due to repeated impacts with the walls of the cell.

[0007] Furthermore, in the case of a shrouded fan, i.e. one comprising a peripheral casing surrounding the fan blades, a defined clearance between the casing and the tip of the blade (or end of the blade opposite the casing) constitutes an important factor in the performance of a turbomachine.

[0008] However, in the case of composite blades, constraints in the manufacture of the blade known as the "head cutting tolerance" requires that the clearance be open, i.e. relatively large, to be able to adapt to the cutting of the blades, which is known late (because it is carried out at the end of the blade manufacturing process) and which can be more or less large, in order to be sure to avoid any contact with the casing during operation. Indeed, during the operation of the turbomachine, various phenomena can modify the distance between the casing and the fan rotor, in particular deviations of the fan rotation shaft or expansions of the casing.

[0009] Usually, the positioning of the blade root in the cell is done by means of a shim arranged under the blade root in the cell and accommodation strips (also called "wearstrips") arranged on either side of the blade root (fixed to the blade root or on opposite walls of the cell) consisting of a coating to protect the interfaces between the blade root and the walls of the cell. EXPOSED

[0010] An aim of the present invention is to remedy one and / or other of the aforementioned drawbacks, by proposing a device for wedging a blade root in the cell of a fan rotor, which makes it possible to avoid the blade root being hammered against the wall of the cell while making it possible to minimize the play between the tip of the blade and the peripheral casing if necessary.

[0011] To this end, according to a first aspect, a device is proposed for wedging a blade root in a cell of a turbomachine rotor disk, comprising a first wedging portion intended to bear against a lateral surface of the blade root, a second wedging portion intended to bear against a lower surface of the blade root, and a connecting portion connecting the first wedging portion to the second wedging portion and intended to bear against a wall of the cell.

[0012] Advantageously, the first wedging portion comprises a part of adjustable thickness and the second wedging portion comprises a means for pressing the blade root onto the first wedging portion.

[0013] Advantageously, the means for pressing the blade root onto the first wedging portion comprises a flexible arm spring.

[0014] Preferably, the part of adjustable thickness is peelable.

[0015] In one embodiment, the adjustable thickness portion comprises a stack of sheets of predetermined thickness capable of being individually removed to reduce the thickness of the adjustable thickness portion, so as to adjust the positioning of the blade root in the cell.

[0016] Advantageously, the first wedging portion, the second wedging portion and the connecting portion are made of metal.

[0017] Advantageously, the wedging device comprises an axial stop extending from the second wedging portion to block the axial sliding of the blade along an extension axis of the rotor disk.

[0018] The present application also relates to an assembly for wedging a blade root in a cell of a turbomachine rotor disk, comprising a first wedging device as defined previously, and a second wedging device as defined previously.

[0019] Preferably, the cell comprises a first lateral flank, a second lateral flank, a bottom connected by a first junction to the first lateral flank and by a second junction to the second lateral flank, the first junction having a first radius of curvature and the second junction having a second radius of curvature, the connecting portion of the first wedging device being configured to at least partially match the first radius of curvature, the first wedging portion of the first wedging device being intended to be inserted between the first lateral flank and the blade root, and the second wedging portion of the first wedging device being intended to be inserted between the bottom and the blade root, and the connecting portion of the second wedging device being configured to at least partially match the second radius of curvature,the first wedging portion of the second wedging device being intended to be inserted between the second lateral flank and the blade root, and the second wedging portion of the second wedging device being intended to be inserted between the bottom and the blade root.

[0020] Advantageously, the second wedging portions of each of the wedging devices are connected to each other so that the first wedging device and the second wedging device are monolithic.

[0021] The present application also relates to a turbomachine fan, comprising a plurality of fan blades, a fan rotor comprising a plurality of cells, each blade of the plurality of blades comprising a blade root received in a cell of the plurality of cells, the fan further comprising at least one wedging assembly as defined previously, said wedging assembly being arranged in one of the cells receiving a blade root, in order to position the blade received in said cell.

[0022] Finally, the present application also relates to a method for adjusting a clearance between the end of a turbomachine fan blade and a peripheral casing surrounding the fan, the blade comprising a blade root, the fan comprising a fan rotor comprising a cell intended to receive the blade root, the method being implemented using a wedging device as defined previously, the first wedging portion of said plating device comprising a adjustable thickness part, the method comprising the following steps:

[0023] - insertion of the wedging device and the blade root into the cell,

[0024] - measurement of the clearance between the casing and the end of the blade opposite the casing,

[0025] - removal of the blade root and the cell wedging device,

[0026] - adjustment of the thickness of the adjustable thickness part of the first portion of setting the setting device according to the measured clearance and a desired clearance,

[0027] - following said adjustment, insertion of the wedging device and the blade root into the alveolus. DESCRIPTION OF FIGURES

[0028] 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:

[0029] [Fig.l] illustrates a schematic view, in axial and partial section, of an example of a turbomachine according to an embodiment of the invention;

[0030] [Fig.2] illustrates a schematic perspective view of a fan rotor in which a blade according to one embodiment of the invention is attached;

[0031] [Fig. 3A] is a schematic cross-sectional view of an exemplary embodiment of a wedging assembly in a cell of a blade root according to a first embodiment, and in which the blade root occupies a low position; and

[0032] [Fig.3B] is a schematic cross-sectional view of an exemplary embodiment of a wedging assembly in a cell of a blade root according to the first embodiment, and in which the blade root occupies a high position; and

[0033] [Fig.4] illustrates a schematic cross-sectional view of an exemplary embodiment of a wedging assembly in a cell of a blade root according to a second embodiment;

[0034] [Fig. 5] illustrates a schematic perspective view of an exemplary embodiment of a wedging assembly according to a third embodiment of the invention;

[0035] [Fig.6] illustrates a partial and schematic cross-sectional view of a shrouded fan rotor for implementing a method according to the invention for adjusting a clearance between a casing and a fan blade;

[0036] [Fig.7] schematically illustrates the different stages of the method according to the invention.

[0037] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0038] In [Fig.l], the turbomachine 1 shown is an aircraft turbomachine. The tur- bomachine 1 comprises a blower 2, a compression section 3, a combustion chamber 4, a turbine section 5 downstream of the combustion chamber 4, and an exhaust casing 50.

[0039] The fan 2 comprises a rotating blade 6. Alternatively, the invention applies to a static blade. In a preferred embodiment of the invention and as is the case in the example illustrated in [Fig.l], the turbomachine 1 may be a turbojet comprising a ducted fan 2, that is to say that the turbomachine 1 comprises a casing 7 surrounding the fan 2 and the fan blade 6. In an alternative embodiment, the turbomachine 1 may in particular be a USF type turboprop comprising an unducted propeller in place of the ducted fan 2, in which case the fan blade is unducted and extends downstream of the propeller.

[0040] The blading 6 comprises by definition a plurality of blades 8. With reference to [Fig.2], each blade 8 comprises a blade root 9 and an aerodynamic blade 10 extending from the blade root 9. The blade 10 therefore comprises a first end 10a connected to the blade root 9 and a second opposite end 10b also called the radial tip of the blade 8, which is opposite the casing 7. The fan 2 further comprises a fan rotor 11 comprising on its periphery a plurality of cells 12 each configured to receive a blade root 9 so as to attach a blade 8 to the fan rotor 11. Thus, each blade root 9 of the plurality of blades 8 is received in one of the cells 12 of the plurality of cells 12. To facilitate understanding of the figures, only one blade 8 is illustrated (partially) in a cell 12 in the example of [Fig.2]. [Fig.2] also illustrates a magnifying glass view of zone A of the blade root 9 inserted in the cell 12.

[0041] In the present application, upstream and downstream are defined relative to the direction of flow of the gases through the blading 6. The axis X is called the axis of rotation of the blades 8 around the rotor of the fan 2 (respectively, of the propeller). The axis X thus corresponds to the axis of rotation of the fan 2, and can also be called the axis of extension of the fan 2 in its length.

[0042] To facilitate the description, the description of a cell 12 and of the fixing of a blade root 9 of a blade 8 in a cell 12 will now be made, a perspective example being illustrated in [Fig. 2]. Nevertheless, said description can apply to one or more, and preferably to all of the other cells 12 receiving a blade root 9 of a blade 8.

[0043] The blade 8 is shaped so as to define a lower surface 8a, an upper surface 8b, a leading edge 8c and a trailing edge 8d. In a manner known per se, the leading edge 8c is configured to extend opposite the flow of gases entering the turbomachine 1. It corresponds to the upstream part of an aerodynamic profile which faces to the airflow and which divides the airflow into an intrados flow and an extrados flow. The trailing edge 8d corresponds to the downstream part of the aerodynamic profile, where the intrados and extrados flows meet.

[0044] The cell 12 is an axial slot along an axis X' substantially parallel to the axis X of rotation of the fan 2. The axis X' is also called the longitudinal axis because it extends along the length of the fan 2, parallel to the axis X but without being confused with the axis X. Unless otherwise specified, the axial direction is thus called the direction corresponding to the axis X' and the radial direction is a direction perpendicular to this axis X' and passing through it. In addition, unless otherwise specified, "internal" and "external" are used with reference to a radial direction so that the internal part or face of an element is closer to the axis X' than the external part or face of the same element.

[0045] As illustrated in Figures 3A and 3B, the cell 12 thus comprises a first lateral flank 13, a bottom 15 and a second lateral flank 17. The cell 12 further comprises a first junction 14 connecting the bottom 15 to the first lateral flank 13, and a second junction 16 connecting the bottom 15 to the second lateral flank 17. The first lateral flank 13, the bottom 15, the second lateral flank 17, the first junction 14 and the second junction 16 form the walls of the cell defining between them a housing intended to receive the blade root 9.

[0046] As illustrated in [Fig.3A], the first lateral flank 13 and the second lateral flank 17 are opposite each other and define between them an external radial opening 18 of the cell 12. In other words, the first lateral flank 13 comprises an external radial end 13a and an internal radial end 13b, and the second lateral flank 17 comprises an external radial end 17a and an internal radial end 17b, the respective external radial ends 13a and 17a of the two lateral flanks 13, 17 defining between them the external radial opening 18.

[0047] The first lateral flank 13 and the second lateral flank 17 are inclined towards each other so that their external radial ends 13a, 17a are closer to each other than their internal radial ends 13b, 17b. The first lateral flank 13 and the second lateral flank 17 thus form bearing surfaces against which the blade root 9 presses when it is received in the cell 12.

[0048] The internal radial end 13b of the first lateral flank 13 is connected to the first junction 14 (i.e., coincides with one end of the first junction 14 in contact with the first lateral flank 13), and the internal radial end 17b of the second lateral flank 17 is connected to the second junction 16 (i.e., coincides with one end of the second junction 16 in contact with the second lateral flank 17).

[0049] The bottom 15 is the wall forming the internal limit of the cell 12, and is radially opposite the external radial opening 18. The bottom 15 connects the first junction 14 to the second junction 16, which are opposite each other.

[0050] The cell 12 is rectilinear from upstream to downstream in the axial direction of the axis X', and thus extends between an upstream open end 12a and a downstream open end 12b. Each of the first lateral flank 13, the second lateral flank 17, the bottom 15 and the junctions 14, 16 thus extends between the upstream open end 12a and the downstream open end 12b.

[0051] The upstream end 12a can be opened so as to be able to insert the blade root 9 by axial sliding along the axis X' from upstream to downstream in the cell 12. Possibly, the downstream end 12b is also open, so that the introduction of the blade root 9 into the cell 12 can be done via the downstream end 12b and / or via the upstream end 12a.

[0052] The first junction 14 may have a first radius of curvature and the second junction 16 may have a second radius of curvature. In one embodiment, the two radii of curvature are identical. Alternatively, the first junction 14 and / or the second junction 16 may have an angle connecting the bottom 15 and the lateral flank 13, 17 respectively at their contact.

[0053] The cell 12 thus has a dovetail shape and the blade root 9 has a dovetail shape complementary to that of the cell 12.

[0054] More specifically, and as illustrated in Figures 2, 3A and 3B, the blade root 9 comprises a first lateral surface 19, a second lateral surface 21 and a lower surface 20 connecting the first lateral surface 19 to the second lateral surface 21. The blade root 9 further comprises an upstream face 9a and a downstream face 9b forming the upstream and downstream ends of the blade root 9 along the axis X'. The upstream face 9a is located under the leading edge 8c of the blade 8 and the downstream face 9b is located under the trailing edge 8d of the blade 8.

[0055] The blade root 9 extends longitudinally, that is to say axially along the axis X', when it is received in the cell 12. In other words, the first lateral surface 19, the second lateral surface 21, and the lower surface 20 each extend longitudinally, that is to say axially along the axis X' between the upstream face 9a of the blade root and the downstream face 9b of the blade root 9 when said blade root 9 is received in the cell 12.

[0056] The first lateral surface 19 and the second lateral surface 21 are opposite and substantially planar, and the lower surface 20 is preferably convex. More preferably, the lower surface 20 has a circular arc shape. The lower surface 20 constitutes the internal radial end of the blade root 9 when it is received in the cell 12.

[0057] The blade root 9 thus preferably has a cross-sectional cut relative to the axis X' in the form of a complementary dovetail to the cell 12 so as to be able to be slid into the cell 12 from an upstream axial end or swallows 12a, 12b of the cell, without being able to escape through the radial external opening 18, which only allows the aerodynamic blade to extend out of the cell 12.

[0058] The cell 12, in a known manner, has dimensions greater than those of the blade root 9 so as to be able to easily slide the blade root 9 axially along the axis X' in said cell 12.

[0059] The invention thus relates to a wedging assembly 25 making it possible to position and maintain the blade root 9 in the cell 12. More precisely, the wedging assembly 25 comprises at least one wedging device, and preferably a first wedging device 30a and a second wedging device 30b, an example of a first embodiment of which is illustrated in FIGS. 2, 3A and 3B.

[0060] The first and second wedging devices 30a, 30b are intended to be positioned on either side of the blade root 9 received in the cell 12. For example, the first wedging device 30a is arranged on the intrados side 8a of the blade 8, that is to say on the side of the first lateral flank 13 of the cell 12 and of the first lateral surface 19 of the blade root 9, and the second wedging device 30b is arranged on the extrados side 8b of the blade 8, that is to say on the side of the second lateral flank 17 of the cell 12 and of the second lateral surface 21 of the blade root 9.

[0061] Each wedging device 30a, 30b comprises a first wedging portion 31a, 31b, a second wedging portion 32a, 32b, and a connecting portion 33a, 33b connecting the first wedging portion 31a, 31b to the second wedging portion 32a, 32b.

[0062] The first wedging portion 31a, 31b is intended to bear against a lateral surface of the blade root 9, in particular the first wedging portion 31a of the first device 30a is intended to bear against the first lateral surface 19, and the first wedging portion 31b of the second device 30b is intended to bear against the second lateral surface 21, as shown in the example illustrated in FIGS. 3A and 3B. In addition, the second wedging portions 32a, 32b of each of the wedging devices 30a, 30b are intended to bear against the lower surface 20 of the blade root 9. Finally, the connecting portions 33a, 33b of each of the wedging devices 30a, 30b are intended to bear against a wall of the cell 12.

[0063] Each of the wedging devices 30a, 30b is intended to be inserted between walls of the cell 12 and the blade root 9 received in the cell 12.

[0064] More precisely, the first wedging portion 31a of the first wedging device 30a is intended to be interposed between the first lateral surface 19 of the blade root 9 and the first lateral flank 13 of the cell 12. Correspondingly, the first wedging portion 31b of the second wedging device 30b is intended to be interposed between the second lateral surface 21 of the blade root 9 and the second flank lateral 17 of the alveolus.

[0065] In addition, the second wedging portions 32a, 32b of each of the wedging devices 30a, 30b are intended to be interposed between the lower surface 20 of the blade root 9 and the bottom 15 of the cell.

[0066] Preferably, the connection portion 33a of the first wedging device 30a is configured to at least partially match the first radius of curvature of the first junction 14. Similarly, the connection portion 33b of the second wedging device 30b is configured to at least partially match the second radius of curvature of the second junction 16.

[0067] In this way, the wedging devices 30a, 30b can bear against the walls of the cell 12 formed by said junctions 14, 16 to maintain the blade root 9 in the desired position.

[0068] The second portion 32a, 32b of each of the wedging devices 30a, 30b comprises a means 34a, 34b for pressing the blade root 9 onto the first wedging portion 31a, 31b of the same wedging device 30a, 30b.

[0069] More specifically, the pressing means 34a, 34b may comprise a flexible arm spring configured to press against the lower surface 21 of the blade root 9. Alternatively, the pressing means 34a, 34b may comprise a leaf spring blade. More specifically and as illustrated in the example of FIGS. 3A, 3B, the pressing means 34a, 34b may be attached to the connecting portion 33a, 33b to which the second portion 32a, 32b is connected. In addition, the pressing means 34a, 34b may comprise a support part 35a, 35b pressing against the lower part of the blade root 9, so as to radially raise the blade root 9 so that said blade root 9 is in a position in which the side walls 19, 21 of the blade root 9 are pressed against the first portions 31a, 31b of the opposite wedging devices 30a, 30b.In this way, the blade root 9 is immobilized in the cell 12, and held against the bearing surfaces formed by the lateral flanks 13 and 17, by means of the first wedging portions 31a, 31b. The first wedging portions 31a, 31b then press against the lateral flank 13, 17 opposite.

[0070] The support portion 35a, 35b may be located on one end of the second portion 32a, 32b opposite the junction 14, 16 to which said second portion 32a, 32b is connected, so that the force exerted by said support portion 35a, 35b on the blade root 9 is maximized.

[0071] The first portion 31a, 31b of each of the wedging devices 30a, 30b may comprise a part of adjustable thickness 36a, 36b in order to adjust the position of the blade root 9 in the cell 12. Preferably, the part of adjustable thickness 36a, 36b is a peelable part. In other words, the part of adjustable thickness 36a, 36b comprises a plurality of sheets of predetermined thickness capable of being removed indi individually, in order to reduce the thickness of the corresponding adjustable thickness portion 36a, 36b.

[0072] The adjustable thickness portion 36a, 36b extends from the first portion 31a, 31b preferably perpendicular to the lateral surface 19, 21 of the blade root 9 arranged opposite said first portion 31a, 31b.

[0073] In this way, the position of the blade root 9 in the cell 12 can be adapted and adjusted, for example as a function of the distance between the aerodynamic blade and the peripheral casing 7, by reducing the thickness of the adjustable thickness portion 36a, 36b.

[0074] Furthermore, the thickness of each of the adjustable thickness parts 36a, 36b can be individually chosen, so as to adapt an inclination of the blade root 9 in the cell 12.

[0075] Figures 3A and 3B illustrate two positions of the blade root 9 in the cell 12 following the adjustment of the thickness of the adjustable thickness portion 36a, 36b. Indeed, in [Fig.3A], the adjustable thickness portion 36a, 36b has a first wide thickness, so that the blade root 9 occupies a low position in the cell 12. The second portion 32a, 32b of the wedging device 30a, 30b is then brought closer to the bottom 15 of the cell 12, so that the top 10b of the aerodynamic blade 10 of the blade 8 (not shown in [Fig.3A]) (or external radial end 10b) is located at a first point at a given distance from the casing 7.

[0076] On the contrary, in [Fig. 3B], the adjustable thickness portion 36a, 36b has a second thickness reduced compared to the first thickness, so that the blade root 9 occupies a higher position in the cell 12 than in [Fig. 3A]. The second portion 32a, 32b of the wedging device 30a, 30b is then further from the bottom 15 of the cell 12, so that the top 10b of the aerodynamic blade 10 of the blade 8 (not shown in [Fig. 3B]) is then in a position located at a second point further radially from the axis X, and therefore closer to the casing 7 than in [Fig. 3A].

[0077] In one embodiment, the first wedging portions 31a, 31b, the second wedging portions 32a, 32b and the connecting portions 33a, 33b are made of metal.

[0078] For example, the second wedging portion 32a, 32b may be made of 45C4 steel.

[0079] For example, the plating means 34a, 34b may be characterized by a modulus of Young's strength of about 150GPa, with a yield strength greater than 500MPa and a tensile strength greater than 1000 MPa.

[0080] In an alternative embodiment illustrated in [Fig. 4], the wedging assembly 25 is monolithic. In other words, the first wedging device 30a and the second wedging device 30b are connected to each other. More specifically, in one embodiment, the second wedging portions 32a, 32b are connected to each other. they by their end opposite the junction 14, 16 to which said second portions 32a, 32b are connected.

[0081] In an embodiment, an example of which is illustrated in [Fig. 5], the wedging assembly 25, and more particularly at least one of the wedging devices 30a, 30b, whether monolithic or not, comprises an axial stop 37 for blocking the axial sliding along the axis X' of the blade root 9 in the cell 12. For example, and as illustrated in [Fig. 5] in which the walls of the cell 12 have not been shown to facilitate understanding and in which the wedging assembly 25 is monolithic, the axial stop 37 extends from the upstream end of the wedging device(s) 30a, 30b, and extends from the second wedging portion(s) 32a, 32b radially outwards when the wedging assembly 25 is inserted into the cell 12.

[0082] The invention also relates to a method for adjusting a clearance 40 defined between the casing 7 and the tip 10b of the blade 10 of the vane 9 (or end 10b of the vane opposite the casing), the description of which follows is illustrated with the aid of figures 6 and 7.

[0083] In a step E1, the wedging device 30a, or more broadly the wedging assembly 25, is inserted into the cell 12 by sliding along the axis X'. Similarly, the blade root 8 is inserted into the cell 12.

[0084] In a second step E2, the clearance 40 between the tip 10b of the blade 8 and the casing 7 is measured.

[0085] In a third step E3, when the clearance 40 is too large, the blade root 9 and the wedging device 30a, where appropriate the wedging assembly 25, is removed from the cell 12 by sliding along the axis X'.

[0086] In a fourth step E4, the thickness of the adjustable thickness portion 36a of the first wedging portion 31a is adjusted. More precisely, depending on the measured clearance 40 and a clearance objective to be achieved, the thickness is adjusted, for example by removing sheets of predetermined thickness, when the adjustable thickness portion 36a is peelable. In parallel, the same operation can be carried out on the adjustable thickness portion 36b of the first wedging portion 31b of the second wedging device 30b.

[0087] In a fifth step E5, when the adjustment is carried out, the wedging device(s) 30a, 30b, as well as the blade root 9, are again inserted into the cell 12.

[0088] In a step E6, the clearance 40 is measured again following the adjustment E4, in order to check whether it corresponds to the clearance objective to be achieved. If this is not the case, the method can be implemented again from step E3, in order to adjust the clearance 40. On the contrary, if the clearance 40 is in accordance with the objective, the method according to the invention can be implemented preferably for all the other blades 8, so that each blade 8 is correctly positioned relative to the casing 7 with a constant clearance 40. from one blade to another. The performance of the turbomachine is then improved, because the air loss is reduced. The disparities between the manufactured blades 8 can thus be taken into account in order to adapt the clearance 40 at the blade tip relative to the casing 7 for each blade 8 specifically. Thus, the clearance 40 of each blade 8 can be adapted individually in order to reduce the air loss as much as possible.

[0089] Thus the wedging device 30a, and more generally the wedging assembly 25, constitute a means for ensuring correct positioning of the blade root 9 in the cell 12, and therefore correct positioning of the blade 8 relative to the casing 7, as well as ensuring correct orientability of the blade 8. In addition, the invention makes it possible to protect the blade root 9 against possible damage in the cell 12.

Claims

Claims

1. Device (30a; 30b) for wedging a blade root (9) in a cell (12) of a rotor disk (11) of a turbomachine (1), comprising a first wedging portion (31a; 31b) intended to bear against a lateral surface (19; 21) of the blade root (9), a second wedging portion (32a; 32b) intended to bear against a lower surface (20) of the blade root (9), and a connecting portion (33a; 33b) connecting the first wedging portion (31a; 31b) to the second wedging portion (32a; 32b) and intended to bear against a wall of the cell (12).

2. Wedging device (30a; 30b) according to claim 1, in which the first wedging portion (31a; 31b) comprises a part of adjustable thickness (36a; 36b) and the second wedging portion (32a; 32b) comprises a means (34a; 34b) for pressing the blade root onto the first wedging portion.

3. Wedging device (30a; 30b) according to claim 2, in which the means (34a; 34b) for pressing the blade root onto the first wedging portion comprises a flexible arm spring.

4. A wedging device (30a; 30b) according to claim 2 or 3, wherein the adjustable thickness portion (36a; 36b) is peelable.

5. Wedging device (30a; 30b) according to claim 4, in which the adjustable thickness portion (36a; 36b) comprises a stack of sheets of predetermined thickness capable of being removed individually to reduce the thickness of the adjustable thickness portion (36a; 36b), so as to adjust the positioning of the blade root (9) in the cell (12).

6. Wedging device (30a; 30b) according to one of claims 1 to 5, in which the first wedging portion (31a; 31b), the second wedging portion (32a; 32b) and the connecting portion (33a; 33b) are made of metal.

7. Wedging device (30a; 30b) according to one of claims 1 to 6, comprising an axial stop (37) extending from the second wedging portion (32a; 32b) to block the axial sliding of the blade (8) along an extension axis (X') of the rotor disc (11).

8. Assembly (25) for wedging a blade root (9) in a cell (12) of a rotor disk (11) of a turbomachine (1), comprising a first wedging device (30a) according to one of claims 1 to 7, and a second wedging device (30b) according to one of claims 1 to 7.

9. A wedging assembly (25) according to claim 8, wherein the cell (12) comprises a first lateral flank (13), a second lateral flank (17), a bottom (15) connected by a first junction (14) to the first lateral flank (13) and by a second junction (16) to the second lateral flank (17), the first junction (14) having a first radius of curvature and the second junction (16) having a second radius of curvature, the connecting portion (33a) of the first wedging device (30a) being configured to at least partially match the first radius of curvature, the first wedging portion (31a) of the first wedging device (30a) being intended to be inserted between the first lateral flank (13) and the blade root (9), and the second wedging portion (32a) of the first wedging device (30a) being intended to be inserted between the bottom (15) and the foot of the blade (9),and the connecting portion (33b) of the second wedging device (30b) being configured to at least partially match the second radius of curvature, the first wedging portion (31b) of the second wedging device (30b) being intended to be inserted between the second lateral flank (17) and the blade root (9), and the second wedging portion (32b) of the second wedging device (30b) being intended to be inserted between the bottom (15) and the blade root,

10. (y)- A wedging assembly (25) according to claim 8 or 9, wherein the second wedging portions (32a; 32b) of each of the wedging devices (30a; 30b) are connected together so that the first wedging device (30a) and the second wedging device (30b) are monolithic.

11. Fan (2) of a turbomachine (1), comprising a plurality of fan blades (8), a fan rotor (11) comprising a plurality of cells (12), each blade (8) of the plurality of blades comprising a blade root (9) received in a cell (12) of the plurality of cells, the fan (2) further comprising at least one wedging assembly (25) according to one of claims 8 to 10, said wedging assembly (25) being arranged in one of the cells (12) receiving a blade root (9), in order to position the blade (8) received in said cell (12).

12. Method for adjusting a clearance (40) between the end (10b) of a blade (8) of a fan (2) of a turbomachine (1) and a peripheral casing (7) surrounding the fan (2), the blade (8) comprising a blade root (9), the fan (2) comprising a fan rotor (11) comprising a cell (12) intended to receive the blade root (9), the method being implemented implemented using a wedging device (30a; 30b) according to one of claims 1 to 7, the first wedging portion (31a; 31b) of said plating device (30a; 30b) comprising a part of adjustable thickness (36a; 36b), the method comprising the following steps: - insertion (El) of the wedging device and the blade root into the cell, - measurement (E2) of the clearance between the casing and the end of the blade opposite the casing, - removal (E3) of the blade root and the cell wedging device, - adjustment (E4) of the thickness of the adjustable thickness part of the first wedging portion of the wedging device according to the measured clearance and a desired clearance, - following said adjustment, insertion (E5) of the wedging device and the blade root into the cell.

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