FR3141489A1 - ASSEMBLY FOR TURBOMACHINE INCLUDING BLOWER DISC AND COMPRESSOR SHAFT - Google Patents

Abstract

An assembly (50) for a turbomachine comprising a compressor shaft (56) and a fan disk (70), wherein the compressor shaft includes a radially outer surface having a first portion (58) including a plurality of main splines (68 ) and a second part (60), the fan disk comprising a radially internal surface comprising a first part (78) comprising a plurality of complementary grooves (88) cooperating with said main grooves (68), and a second part (80) bearing on the second part (60) of the compressor shaft, in which the second part (60) of the compressor shaft and the second part (80) of the fan disk are frustoconical, the assembly comprising in in addition to a wedge (90), the compressor shaft (56) and the fan disc (50) bear substantially axially on opposite sides of the wedge (90). Abstract Figure: Figure 2

Description

ASSEMBLY FOR TURBOMACHINE INCLUDING BLOWER DISC AND COMPRESSOR SHAFT

The present disclosure relates to an assembly for a turbomachine comprising a fan disk and a compressor shaft.

Conventionally, a turbomachine is equipped with a fan and at least one compressor, in particular a low pressure compressor (also subsequently called a “LP compressor”).

There shows a schematic view in longitudinal section of a detail of an assembly 10 formed by the fan, referenced 12, and the LP compressor, referenced 14, according to the prior technique. The blower 12 and the LP compressor 14 are only partially represented on the .

The BP compressor 14 comprises a shaft 16 of generally cylindrical shape with longitudinal axis A. The shows only an upstream part of shaft 16.

The shaft 16 comprises a radially outer surface 16-1 and a radially inner surface 16-2.

The radially outer surface 16-1 of the shaft 16 comprises a first part 18 having a first radius R1 and a second part 20 having a radius R2. The radii R1 and R2 are measured relative to the axis A of the shaft 16. As is clear from the , the radius R1 is less than the radius R2.

The first part 18 comprises a thread 22 adapted to screw a nut 24 for tightening the fan 12 onto the shaft 16 of the LP compressor 14.

The second part 20 comprises a substantially cylindrical portion 26 comprising a plurality of grooves 28. Each groove 28 comprises a blind groove (not visible on the ) set back radially in the second part 20 of the shaft 16 and which is delimited laterally between two teeth 28-1. Advantageously, each groove 28 extends substantially parallel to the axis A over the entire length of the portion 26.

The second part 20 also comprises another substantially cylindrical portion 27 located longitudinally behind the portion 26.

The fan 12 comprises a fan disk 30. The fan disk 30 comprises a body 32, one or more lug(s) 34 and a fixing flange 36.

The body 32 has a substantially cylindrical shape preferably coaxial with the axis A. The body 32 comprises a radially external surface 32-1 and a radially internal surface 32-2.

Each tab 34 extends substantially radially from the radially internal surface 32-2 of the body 32 to the fixing flange 36.

The fixing flange 36 has a general cylindrical shape coaxial with the axis A. Also, the fixing flange 36 is substantially parallel to the body 32 of the disc 30.

The fixing flange 36 comprises a radially outer surface 36-1 and a radially inner surface 36-2.

The radially internal surface 36-2 comprises a first part 38 and a second part 40.

The first part 38 comprises a substantially annular portion 42 projecting radially relative to the rest of the radially internal surface 36-2.

The second part 40 comprises a substantially cylindrical portion 44 and a portion 46 comprising a plurality of grooves 47.

The portion 46 with grooves 47 has a substantially cylindrical shape and is located longitudinally in front of the portion 44. Each groove 47 includes a blind groove (not visible on the ) and which is delimited laterally between two teeth 47-1 projecting radially relative to the rest of the second part 40. Advantageously, each groove 47 of the flange extends substantially parallel to the axis A over the entire length of the portion 26 .

Each spline 47 has a shape complementary to the shape of one of the splines 28 of the portion 26 of the shaft 16.

As it appears from the , in the assembly 10, the radially internal surface 36-2 of the flange 36 is radially opposite the radially external surface 16-1 of the shaft 16. Thus, each tooth 28-1 is received between two teeth 47-1, which ensures the connection in rotation around the axis A of the shaft 16 and the disk 30.

In order to ensure centering between the fan disk 30 and the shaft 16 of the compressor 14, the radially internal surface 36-2 of the flange 36 is shaped to be in contact with the first part 18 and the second part 20 of the radially outer surface 16-1 of the shaft 16. As is clear from the , the portion 42 and the portion 44 of the radially internal surface 36-2 are respectively in contact with the first part 18 and the portion 27 of the second part 20 of the shaft 16.

However, as indicated previously, the radius R1 of the first part 18 is different from the radius R2 of the second part 20. More precisely, the change from the radius R1 of the first part 18 to the radius R2 of the second part 20 is done so brutal. Thus, in the prior art it is necessary for the portions 42 and 44 of the flange 36 to be machined with dimensions having precise values, particularly in their radial direction. Likewise, it is necessary to ensure that the machined shaft 16 has precise values of the radii R1 and R2. Indeed, any deviation from these precise values for one of the portions 42, 44, or for one of the radii R1, R2, prevents the two portions 42, 44 from being in contact with the radially external surface 16-1 of the shaft 16, which deteriorates the quality, or even prevents, the centering between the fan disk 30 and the shaft 16.

The values of the radial dimensions of the portions 42, 44 and the radii R1 and R2 therefore have a low tolerance (that is to say, the difference between the minimum value and the maximum value that they can have to ensure assembly correct of the disc 30 on the shaft 16 is weak) and are connected together by a tight dimension. The manufacture of the shaft 16 and the disk 30 is therefore long and complex, and involves a high risk of obtaining unusable parts.

Summary

This disclosure improves the situation.

For this purpose, there is proposed an assembly for a turbomachine comprising a compressor shaft and a fan disc, the compressor shaft extending along a longitudinal axis, the fan disc being mounted on the compressor shaft around said longitudinal axis, wherein the compressor shaft comprises a radially outer surface having a first part comprising a plurality of main splines and a second part, the fan disk comprising a radially inner surface having a first part comprising a plurality of splines complementary cooperating with said main splines to ensure the rotational connection of the fan disk and the compressor shaft, and a second part bearing on the second part of the compressor shaft, in which the second part of the compressor shaft and the second part of the fan disc are frustoconical, the assembly further comprising a wedge, the compressor shaft bearing substantially axially on a first side of the wedge, the fan disc bearing substantially axially of a second side of the wedge opposite said first side.

The centering of the fan disk on the compressor shaft is then carried out in the radial direction from the support of the second part of the fan disk on the second part of the compressor shaft. It is therefore sufficient, when manufacturing the fan disc and the compressor shaft, to ensure that the axial dimensions of the first parts and the second parts of the compressor shaft and the fan disc, and the inclinations second parts relative to the longitudinal axis, allow the second part of the fan disk to come to bear on the second part of the compressor shaft when the first part of the fan disk and the first part of the compressor shaft compressor cooperate with each other. Also, unlike the prior art, in the present assembly it is not necessary to apply small tolerances on two distinct diameters of the compressor shaft and the fan disk during their manufacture to guarantee the centering of the disk. blower on the compressor shaft.

The manufacturing of the compressor shaft, the fan disk, and therefore the assembly that they form, is thus simpler, less expensive and presents a reduced risk of obtaining unusable parts.

In addition, the centering of the fan disk on the compressor shaft being ensured by the support of the second part of the fan disk on the second part of the compressor shaft, which are both frustoconical, it is possible to redistribute the mass gained compared to the prior technique in which such centering is obtained by supporting the fan disk on two parts of the compressor shaft having a sudden change in diameter between them. Indeed, in the prior art, the sudden change in diameter between each part of the compressor shaft or the fan disk is obtained by removal of material, which involves not only economic losses, but also a loss of mass of the compressor shaft and the blower disc. The centering ensured by the contact between the second frustoconical parts of the compressor shaft and the fan disk therefore makes it possible to obtain a gain in mass which can be concentrated in particular on the first parts of the compressor shaft and the fan disk. fan, as well as on the second parts of the compressor shaft and the fan disc. The connection between the compressor shaft and the fan disk is thus more robust, which is of major interest in the event of ultimate loads.

Furthermore, thanks to the wedge on which the compressor shaft and the fan disk rest axially, it is possible to maintain the fan disk axially in position relative to the compressor shaft, which makes it possible to guarantee centering the fan disc on the compressor shaft also in the axial direction.

The shim is for example an added shim, easily machinable and inexpensive. It is therefore possible to manufacture a specific shim for each assembly, the shim having substantially the same dimensions of an axial clearance existing between the fan disk and the compressor shaft of the corresponding assembly.

In the present text, by “radial” is meant substantially perpendicular to the longitudinal axis of the compressor shaft, and by “axial” or “longitudinal” is meant substantially parallel to said longitudinal axis.

The compressor is for example a low pressure compressor.

The compressor shaft may have a hollow elongated shape. In particular, a cavity can pass axially through the compressor shaft, for example over its entire length.

The longitudinal axis of the compressor shaft is for example substantially parallel to a longitudinal axis of the turbomachine. The longitudinal axis of the compressor shaft and the longitudinal axis of the turbomachine can be coincident.

Each main and complementary groove includes for example a blind groove.

Each main groove can also comprise two main teeth laterally delimiting the respective blind groove. Likewise, each complementary groove may comprise two complementary teeth laterally delimiting the respective blind groove.

Each main tooth and each complementary tooth can project radially from, respectively, the first part of the compressor shaft and the first part of the fan disk. For example, each main and complementary tooth can project radially between 30 mm and 60 mm, preferably between 40 mm and 50 mm relative to, respectively, the first part of the compressor shaft and the first part of the fan disk .

Advantageously, each main tooth can be shared by two adjacent main splines, and each complementary tooth can be shared by two adjacent complementary splines. This makes manufacturing the assembly simpler and faster and reduces its weight.

Advantageously, each main tooth is able to be positioned between two successive complementary teeth. More precisely, each main tooth can be shaped to be positioned in an adjusted manner between two complementary teeth. The rotational connection of the fan disk and the compressor shaft is thus guaranteed. In particular, the positioning of one of the main teeth between two successive complementary teeth, in particular in an adjusted manner, causes that when the compressor shaft is rotated around its longitudinal axis, the main tooth comes into abutment with the one of the complementary teeth between which it is positioned. The rotational movement of the compressor shaft can thus be transmitted to the fan disk, which then rotates integrally with the compressor shaft.

The plurality of main teeth and complementary teeth are advantageously arranged on, respectively, the first part of the compressor shaft and the first part of the fan disk such that during the entire rotational movement of the compressor shaft around its longitudinal axis, at least one of the main teeth is arranged between two complementary teeth.

According to one aspect, the wedge can be arranged radially around the compressor shaft and comes to bear substantially axially on a downstream end portion of the fan disk.

In this text, the terms "upstream" and "downstream" are to be interpreted in relation to the direction of flow of a flow of air drawn into the turbomachine and passing longitudinally through the turbomachine between its two ends.

The wedge bearing substantially axially on the downstream end of the fan disk, the axial centering of the fan disk on the compressor shaft is possible without the need to create intermediate zones on the fan disk and the compressor shaft. exhibiting abrupt changes in diameter.

The wedge may have a substantially annular shape. Advantageously, a radially internal diameter of the shim can be substantially equal to a radially external diameter of the compressor shaft, so that the shim is mounted adjusted or tightened around the compressor shaft.

According to one aspect, the wedge may be elastically deformable.

Thanks to the fact that the wedge is elastically deformable, the fan disk can come to bear both on the second part of the compressor shaft and on the wedge, and the compressor shaft can come to bear both on the second part of the fan disk and on the wedge.

The wedge can be made of metallic material, for example the same material of the fan disk and/or the compressor shaft. The wedge is for example made of titanium or steel.
The wedge may have an axial section comprising at least one hollow part to guarantee elastically deformable behavior. For example, the wedge can have a U-shaped axial section to guarantee this elastically deformable behavior.

According to one aspect, the assembly may further comprise a nut configured to exert a substantially axial force on at least one of the compressor shaft or the fan disk so as to maintain the substantially axial support of the shaft compressor and the blower disk on the wedge.

The nut can be screwed onto a thread provided on the compressor shaft and exert the axial force on the fan disc. The nut can exert the axial force directly on the upstream end of the fan disk. Thanks to this axial force, the fan disk can move axially on the compressor shaft until the shim is axially in contact with the fan disk and the compressor shaft. Advantageously, the force exerted by the nut on the fan disk exceeds the force necessary to bring the fan disk and the compressor shaft into axial contact with the wedge. Also, the shim can compress axially between the fan disc and the compressor shaft, thereby ensuring that no axial play remains between the fan disc and the compressor shaft. The axial force exerted by the nut subsequently makes it possible to hold the fan disk axially in position relative to the shim so that no axial play appears between the fan disk and the compressor shaft, guaranteeing thus the correct axial centering of the fan disk in relation to the compressor shaft.

Alternatively, the nut can be screwed onto a thread provided on the fan disc and exert the axial force on the compressor shaft.

The axial force exerted by the nut can be adjusted manually by screwing or unscrewing it on the corresponding thread.

The nut may have a substantially annular shape capable of being screwed onto the compressor shaft or the fan disk.

According to one aspect, the axial dimension of the second part of the compressor shaft may be greater than the axial dimension of the first part of the compressor shaft, and the axial dimension of said second part of the fan disk may be greater to the axial dimension of the first part of the fan disk.

Here, the axial dimensions of the first part of the compressor shaft, the first part of the fan disk, the second part of the compressor shaft and the second part of the fan disk are understood to be the dimension of the projection in the radial direction of each of these parts on the longitudinal axis of the compressor shaft.

The axial dimension of the second part of the compressor shaft being greater than the axial dimension of the first part of the compressor shaft, and the axial dimension of the second part of the fan disk being greater than the axial dimension of the first part of the fan disc, the risk of collision between the main splines and the complementary splines when mounting the fan disc on the compressor shaft is reduced. In particular, as the axial dimension of the second parts of the compressor shaft and the fan disk is larger than the axial dimension of the first parts of the compressor shaft and the fan disk, when mounting the disk on the shaft, the second part of the fan disk comes to support the second part of the compressor shaft before the first parts of the compressor shaft and the fan disk are radially opposite each other. one from the other. This makes it possible to check in advance that the main splines and the complementary splines are not in a position in which they could collide axially. If, on the contrary, they are in such a position, the fan disc (or the compressor shaft) can be rotated around the longitudinal axis at an angle to avoid such a collision.

An axial dimension of each main and complementary groove may be equal to the axial dimension of, respectively, the first part of the compressor shaft and the first part of the fan disk.

The blind groove included in each main and complementary groove can extend over the entire axial dimension of the first part of the compressor shaft and the first part of the fan disk respectively.

Each main tooth and each complementary tooth extends for example over the entire axial dimension of, respectively, the first part of the compressor shaft and the first part of the fan disk.

According to one aspect, the axial dimension of the first part of the compressor shaft and the axial dimension of the first part of the fan disk can be between 100 mm and 200 mm, preferably between 125 mm and 175 mm.

The main and complementary splines are thus long enough in the axial direction to ensure that all rotational forces can be transmitted from the compressor shaft to the fan disc.

According to a non-limiting example, the axial dimension of the first part of the compressor shaft is equal to the axial dimension of the first part of the fan disk.

According to one aspect, the axial dimension of the second part of the compressor shaft and the axial dimension of the second part of the fan disk can be between 200 mm and 400 mm, preferably between 250 mm and 350 mm.

The second part of the compressor shaft and the second part of the fan disc are thus sufficiently long to limit the risk of collision between the main splines and the complementary splines when mounting the fan disc on the compressor shaft.

According to a non-limiting example, the axial dimension of the second part of the compressor shaft is equal to the axial dimension of the second part of the fan disk.

According to one aspect, the second part of the compressor shaft and the second part of the fan disk can form an angle with the longitudinal axis of the compressor shaft of between 15° and 50°, preferably between 20° and 40°. The inclination of the fan disk on the compressor shaft is thus low.

The angle formed with the longitudinal axis of the compressor shaft by the second part of the compressor shaft may be the same as the angle formed by the second part of the fan disk with this longitudinal axis. This allows the second part of the fan disk to rest over its entire length on the second part of the fan disk, which improves the stability of the assembly.

According to one aspect, said first part of the compressor shaft and said first part of the fan disk may be cylindrical. In such cases, each main spline and each complementary spline may extend substantially parallel to the longitudinal axis of the compressor shaft.

According to one aspect, said first part of the compressor shaft and said first part of the fan disk may be frustoconical. The centering of the fan disc on the compressor shaft can therefore also be a conical centering at the level of the first part of the compressor shaft and the first part of the fan disc.

In such cases, the main splines and the complementary splines may extend so as to form with the longitudinal axis of the compressor shaft the same angle as, respectively, the first part of the compressor shaft and the first part of the fan disk forms with this longitudinal axis. The main grooves and the complementary grooves thus cooperate with each other with conical contact.

According to one aspect, said first part of the compressor shaft and said first part of the fan disk can form an angle with the longitudinal axis substantially equal to the angle formed by said second part of the compressor shaft and said second part of the fan disk with said longitudinal axis.

This reduces the risk of loss of concentricity between the first part of the compressor shaft and the second part of the compressor shaft, as well as between the first part of the fan disk and the second part of the fan disk.

In addition, this makes it possible to use the assembly used to machine the second part of the compressor shaft and the second part of the fan disk to respectively machine the first part of the compressor shaft and the first part of the fan disk , which reduces the assembly manufacturing time.

According to one aspect, said first part of the compressor shaft and said first part of the fan disk can be arranged respectively upstream of said second part of the compressor shaft and said second part of the fan disk.

Typically, a mounting direction of the fan disk on the compressor shaft corresponds to the direction of flow of the air flow sucked in by the turbomachine. Also, when the axial dimension of the second parts of the compressor shaft and the fan disk is greater than the axial dimension of the first parts of the compressor shaft and the fan disk, during assembly of said second assembly parts come into contact with each other before said first parts. This prevents the main and complementary splines from colliding axially during assembly, as explained previously.

In some cases, the first portion of the compressor shaft is longitudinally separated from the second portion of the compressor shaft by a portion that is radially recessed relative to the first portion of the compressor shaft and the second portion of the compressor shaft. Likewise, the first part of the fan disk is separated longitudinally from the second part of the fan disk by a part which is radially recessed relative to the first part and the second part of the fan disk.

In other cases, the part longitudinally separating the first part of the compressor shaft and the second part of the compressor shaft is depressed radially only with respect to one of the first part of the compressor shaft and the second part of the compressor shaft, and the part longitudinally separating the first part of the fan disk and the second part of the fan disk is depressed radially only with respect to one of the first part of the fan disk and the second part of the blower disk.

According to another aspect, there is proposed an assembly for a turbomachine comprising a compressor shaft and a fan disk, the compressor shaft extending along a longitudinal axis, the fan disk being mounted on the fan shaft. compressor about said longitudinal axis, wherein the compressor shaft comprises a radially outer surface having a first part comprising a plurality of main splines and a second part, wherein the fan disk comprises a radially inner surface having a first part comprising a plurality of complementary splines shaped to cooperate with said main splines to ensure the rotational connection of the fan disk relative to the compressor shaft, and a second part bearing on said second part of the compressor shaft, in which said second part of the compressor shaft and the second part of the fan disk are frustoconical, in which an axial dimension of said second part of the compressor shaft is greater than an axial dimension of said first part of the compressor shaft compressor, and an axial dimension of said second part of the fan disk is greater than an axial dimension of said first part of the fan disk.

According to another aspect, a turbomachine is proposed such as a turbojet or a turboprop, comprising an assembly as described above.

As indicated previously, the manufacture of the assembly described above is simpler and less expensive. Consequently, the manufacture of the turbomachine comprising such an assembly is also simplified and less expensive. All the other advantages conferred by the assembly described above are also applicable to such a turbomachine.

Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which:

Fig. 1

is a schematic view in longitudinal section of a detail of an assembly for a turbomachine according to the prior art and described above.

Fig. 2

is a schematic view in longitudinal section of a detail of an assembly for a turbomachine according to a first embodiment of the invention.

Fig. 3

is a schematic longitudinal couple view of a detail of an assembly for a turbomachine according to a second embodiment of the invention.

There represents a schematic view in longitudinal section of a detail of an assembly 50 for a turbomachine according to a first embodiment of the invention. The assembly 50 includes a fan 52 and a compressor 54, in particular a LP compressor. The blower 52 and the BP compressor 54 are only partially represented on the .

The BP 54 compressor includes a shaft 56, only an upstream part of which is visible on the . The shaft 56 extends along and around a longitudinal axis B. The axis B is preferably substantially parallel to the longitudinal axis of the turbomachine. Axis B is for example coincident with the longitudinal axis of the turbomachine.

Advantageously, a cavity 57 passes through the shaft 56. The cavity 57 preferably extends substantially in the axial direction, for example over the entire length of the shaft 56. Also, the shaft 56 comprises a radially external surface 56- 1 and a radially internal surface 56-2.

The radially external surface 56-1 of the shaft 56 comprises a first part 58 and a second part 60. In the following, the first part 58 of the shaft 56 will also be called "main splined part", and the second part 60 of the shaft 56 will also be called “main guide part”.

The main grooved part 58 and the main guide part 60 are arranged longitudinally one after the other. In particular, as will be detailed, the main grooved part 58 is located upstream of the main guide part 60. As indicated previously, in the present text, the terms "upstream" and "downstream" are to be interpreted in relation to the classic direction of flow of a flow of air sucked in by the turbomachine, this direction of flow also corresponding to a direction of mounting S1 of the fan 52 on the compressor 54, as will be detailed below.

The radially external surface 56-1 of the shaft 56 further comprises a third part 59 longitudinally separating the main grooved part 58 and the main guide part 60. On the , the third part 59 is radially depressed relative to the main grooved part 58 and the main guide part 60. Alternatively, the third part 59 could be radially depressed relative to only the main grooved part 58 or the main guide part 60.

The main grooved part 58 is for example substantially cylindrical. In particular, the main grooved part 58 has a general cylindrical shape with axis B. Advantageously, the axial dimension L1 of the main grooved part 58 is between 100 mm and 200 mm, preferably between 125 mm and 175 mm.

The main grooved part 58 comprises a plurality of main grooves 68 extending substantially parallel to the axis B. Preferably each main groove 68 extends over the entire axial dimension L1 of the main grooved part 58. More precisely, the dimension axial of each main groove 68 can be equal to the dimension L1 of the grooved part 58.

Each main groove 68 includes a blind groove (not visible on the ) extending substantially parallel to axis B over the entire axial dimension of the respective groove 68. Each main groove 68 also comprises two main teeth 68-1 laterally delimiting the respective blind groove. Preferably, each main tooth 68-1 extends over the entire dimension of the respective main groove 58.

Each main tooth 68-1 projects radially from the main grooved part 68. For example, each main tooth 68-1 can project radially from the main grooved part between 30 mm and 60 mm, preferably between 40 mm and 50 mm.

Each main tooth 68-1 is advantageously shared by two adjacent main grooves 68. This makes it possible to simplify and accelerate the manufacture of the shaft 56, as well as to reduce its weight and its bulk.

The main guide part 60 is substantially frustoconical. In particular, the main guide part 60 has a general truncated cone shape with axis B. Thus, the main guide part 60 is inclined relative to the axis B. An angle formed between the axis B and the main guide part 60 is for example between 15° and 50°, preferably between 20° and 40°.

Advantageously, an axial dimension L2 of the main guide part 60 is greater than the axial dimension L1 of the main grooved part 58. For example, the axial dimension L2 of the main guide part 60 is between 200 mm and 400 mm, preferably between 250 mm and 350 mm.

As it appears from the , an upstream end portion of the shaft 56 may comprise a thread 67. A downstream end portion of the shaft 56 may comprise a portion 69 projecting radially outwards from the radially outer surface 56-1 of the shaft 56. A side face 69-1 of the portion 69 forms an axial stop, as will be detailed below.

The fan 52 includes a fan disk 70, partially visible on the . The blower disk 70 is mounted on the compressor shaft 56, as will be detailed.

The fan disk 70 comprises a body 72, one or more lug(s) 74 and a fixing flange 76.

The body 72 has a substantially cylindrical shape preferably coaxial with the axis B. The body 72 comprises a radially external surface 72-1 and a radially internal surface 72-2. The radially outer surface 72-1 of the body 72 also corresponds to a radially outer surface of the disc 70.

A plurality of blades (not illustrated) extending substantially radially relative to the disk 70 are arranged on the radially external surface 72-1 of the body 72.

Each tab 74 extends substantially radially from the radially internal surface 72-2 of the body 72 to the fixing flange 76. Each tab 74 is for example substantially inclined relative to a direction perpendicular to the axis B.

The fixing flange 76 comprises a radially outer surface 76-1 and a radially inner surface 76-2. The radially internal surface 76-2 of the flange 76 also corresponds to a radially internal surface of the disk 70.

The disk 70 comprises along the radially internal surface 76-2 a first part 78 and a second part 80. In what follows, the first part 78 of the fan disk 70 will also be called "complementary grooved part", and the second part 80 of the flange 76 of the fan disk 70 will also be called “complementary guide part”.

The complementary grooved part 78 and the complementary guide part 80 are arranged longitudinally one after the other. In particular, as will be detailed, the complementary grooved part 78 is located upstream of the complementary guide part 80.

The radially internal surface 76-2 of the disc 70 also comprises a third part 79 longitudinally separating the complementary grooved part 78 and the complementary guide part 80. On the , the third part 79 is radially depressed relative to the complementary grooved part 78 and the complementary guide part 80. Alternatively, the third part 79 could be radially depressed relative to only the complementary grooved part 78 or the complementary guide part 80.

The complementary grooved part 78 is for example substantially cylindrical. In particular, the complementary grooved part 78 has a general cylindrical shape with axis B. Advantageously, the axial dimension L3 of the complementary grooved part 78 is between 100 mm and 200 mm, preferably between 125 mm and 175 mm. The axial dimension L3 of the complementary grooved part 78 can in particular be equal to the axial dimension L1 of the main grooved part 58.

The complementary grooved part 78 comprises a plurality of complementary grooves 88 extending substantially parallel to the axis B. Preferably each complementary groove 88 extends over the entire axial dimension L3 of the complementary grooved part 78. More precisely, the dimension axial of each complementary groove 78 can be equal to the dimension L3 of the complementary grooved part 78.

Each complementary groove 88 includes a blind groove (not visible on the ) extending substantially parallel to axis B over the entire axial dimension of the respective groove 88. Each complementary groove 88 also comprises two complementary teeth 88-1 laterally delimiting the respective blind groove. Preferably, each complementary tooth 88-1 extends over the entire dimension of the respective complementary groove 88.

Each complementary tooth 88-1 projects radially from the complementary grooved part 78. For example, each complementary tooth 88-1 can project radially from the complementary grooved part between 30 mm and 60 mm, preferably between 40 mm and 50 mm.

Each complementary tooth 88-1 is advantageously shared by two adjacent complementary grooves 78. This makes it possible to simplify and accelerate the manufacture of the disk 70, as well as to reduce its weight and its size.

The complementary grooved part 78 is arranged radially opposite the main grooved part 58. The plurality of complementary grooves 88 are shaped to cooperate with the main grooves 68 so as to ensure the rotational connection of the fan disk 70 and of the compressor shaft 56. In particular, each main tooth 68-1 is able to be positioned between two successive complementary teeth 88-1. Advantageously, each main tooth 68-1 can be shaped to be positioned in an adjusted manner between two complementary teeth 88-1. Also, when the shaft 56 is rotated around the axis B, the main tooth 68-1 abuts against one of the complementary teeth 88-1, which makes it possible to drive the fan disk 70 in rotation around axis B integrally with shaft 56.

The complementary guide part 80 is substantially frustoconical. In particular, the complementary guide part 80 has a general shape of a truncated cone of axis B. Thus, the complementary guide part 80 is inclined relative to the axis B. An angle formed between the axis B and the complementary guide part 80 is for example between 15° and 50°, preferably between 20° and 40°. Advantageously, the angle formed between axis B and the complementary guide part 80 is substantially equal to the angle formed between axis B and the main guide part 60.

Advantageously, an axial dimension L4 of the complementary guide part 80 is greater than the axial dimension L3 of the complementary grooved part 78. For example, the axial dimension L4 of the complementary guide part 80 is between 200 mm and 400 mm, preferably between 250 mm and 350 mm. The axial dimension L4 of the complementary guide part is for example equal to the axial dimension L2 of the main guide part 60.

As it appears from the , the complementary guide part 80 comes to support the main guide part 60. Preferably, the entire complementary guide part 80 comes to support the main guide part 60, without this being limiting. The support of the entire complementary guide part 80 on the main guide part 60 is notably obtained when the angle formed between the axis B and the complementary guide part 80 is substantially equal to the angle formed between the axis B and the main guide part 60.

The main guide parts 60 and complementary 80 being frustoconical, the support of the complementary guide part 80 on the main guide part 60 forms a centering of the disc 70 on the shaft 56 in the radial direction of conical type.

Note, as explained previously, that thanks to the conical centering ensured by the support of the complementary guide part 80 on the main guide part 60, the manufacture of the shaft 56, the disc 70 and the assembly 50 is simpler, less expensive and has a reduced risk of obtaining unusable parts. Furthermore, as also explained, such centering makes it possible to obtain a more robust connection between the shaft 56 and the disk 70.

To guarantee the centering of the disc 70 on the shaft 56 in the axial direction, the assembly may include a nut 84 and/or a shim 90. On the example of the , the assembly 50 includes the nut 84 and the shim 90.

The nut 84 has, for example, a substantially annular shape. In particular, the nut 84 is shaped so as to be able to be connected to the thread 67 of the upstream end portion of the shaft 56. To this end, the nut 84 comprises on a radially internal surface a thread 85 complementary to the thread 67 of shaft 56.

The nut 84 exerts an axial force on an upstream end of the flange 76. The axial force exerted by the nut 84 is adjusted, for example manually, by screwing or unscrewing the nut 84 on the thread 67.

As indicated, the shim 90 is advantageously an easily machinable and inexpensive insert making it possible to fill the axial clearance between the disc 70 and shaft 56. For this purpose, the shim 90 is for example arranged between a downstream end of the flange 76 and the stop 69-1 of the shaft 56. The wedge 90 has for example a substantially annular shape having a radially internal diameter substantially equal to a radially external diameter of the shaft 56. Also, the wedge 90 can be mounted adjusted or tightened around of shaft 56.

The wedge 90 can be made of metallic material. Preferably, the wedge 90 is made of the same material as the fan disk 70 and/or the shaft 56. The wedge 90 is for example made of titanium or steel.

Advantageously, the wedge 90 is elastically deformable. For this purpose, the wedge 90 can have a U-shaped axial section, as illustrated in the .

When the nut 84 is screwed onto the thread 67, the disc 70 is moved axially on the shaft 56 in the direction of approach of the stop 69-1. Advantageously, the nut 84 is screwed onto the thread 67 until the disc 70 comes into axial support on a first side of the wedge 90, and the stop 69-1 of the shaft 56 comes into axial support on a second side of the wedge 90 opposite axially to its first side. Thus, the axial centering of the disk 70 on the shaft 56 is ensured.

Thanks to the elastically deformable behavior of the wedge 90, it is possible to guarantee both the support of the fan disk 70 on the wedge 90 and on the main guide part 60 of the compressor shaft. It is thus possible to center the disc 70 radially and axially on the shaft 56.

We note that even if on the the assembly 50 includes the nut 84 and the shim 90, the axial centering of the disc 70 on the shaft could also be achieved by omitting one of the two. For example, the axial centering could be carried out using only the shim 90, the latter being machined with dimensions making it possible to fill the axial play existing in the assembly 50 between the disc 70 and the shaft 56.

There represents a schematic view in longitudinal section of a detail of an assembly 100 for a turbomachine according to another embodiment of the invention. Assembly 100 is distinguished from assembly 50 of the in that the main grooved part 58 and the complementary grooved part 78 are substantially frustoconical. In particular, on the form of realization of the , the main grooved part 58 and the complementary grooved part 78 have a general truncated cone shape with axis B. The main grooves 68 and complementary 88 can therefore extend so as to form a non-zero angle with the axis B , and they may include blind grooves (not visible on the ) also extending so as to form a non-zero angle with the axis B.

According to a non-limiting example, the main 58 and complementary 78 grooved parts can form an angle with the axis B substantially equal to the angle formed by the main 60 and complementary 80 guide parts. This reduces the risk of loss of concentricity between the main grooved parts 58 and complementary 78 and, respectively, the main guide parts 60 and complementary 80. In addition, this makes it possible to use the assembly used to machine the guide parts 60, 80 to also machine the grooved parts 58 , 78.

The rest of the characteristics of the assembly 50 described with reference to the are applicable to assembly 100 of the . For the sake of brevity, they will not be redescribed below.

The present disclosure also relates to a turbomachine (not illustrated) comprising assembly 50 or assembly 100 as described above.

A method of mounting the assembly 50 or the assembly 100 will now be described.

The disk 70 is mounted on the shaft 56 by moving it substantially parallel to the axis B in a mounting direction S1. As indicated previously, the mounting direction S1 corresponds to the classic direction of flow of the air flow sucked into the turbomachine.

The upstream end of the shaft 56 is thus introduced into the flange 76, the disc 70 being moved towards the downstream end of the shaft 56. During this movement, the complementary guide part 80 comes into contact with the main guide part 60.

As indicated previously, the main guide part 60 and the complementary guide part 80 have axial dimensions L2 and L4 greater than, respectively, the axial dimension L1 of the main grooved part 58 and the axial dimension L3 of the complementary grooved part 78 Also, when the complementary guide part 80 comes into contact with the main guide part 60, the complementary grooved part 78 is not yet facing radially the main grooved part 58. This makes it possible to check. anticipated manner that the main splines 68 and the complementary splines 88 are not in a position in which they could collide axially, in particular by axial collision of the main teeth 68-1 with the complementary teeth 88-1. If, on the contrary, they are in such a position, the fan disk 70 (or the compressor shaft 56) can be rotated around the axis B at an angle allowing such a collision to be avoided.

The disc 70 is moved from upstream to downstream on the shaft 56 until the complementary grooved part 78 and the complementary guide part 80 are entirely facing, respectively, the main grooved part 58 and the main guide part 60. The conical centering in the radial direction of the disc 70 on the shaft 56 is thus guaranteed thanks at least to the support of the complementary guide part 80 on the main guide part 60.

Then, in order to axially center the disc 70 on the shaft 56, the nut 84 is screwed onto the thread 67. By screwing the nut 84, the disc 70 is again moved towards the downstream end of the shaft 56 under the effect of the axial force exerted by the nut 84. During the movement of the disc 70 caused by the nut 84, the disc 70 comes into contact with the wedge 90. The elastically deformable wedge 90 being arranged between the disc 70 and the projecting portion 68 of the shaft 56, it is compressed between the disc 70 and the shaft 56 as the nut 84 is screwed, thus guaranteeing that no axial play remains between the fan disk 70 and the compressor shaft 56. The disk 70 is thus centered axially on the shaft 56.

The assembly process described above therefore makes it possible to guarantee that the disc 70 is centered on the shaft 56 axially and radially, the radial centering being of the conical type.

The present disclosure is not limited to the examples of assembly and assembly method described above, only by way of example, but it encompasses all the variants that those skilled in the art may consider in the context of the protection sought.

Claims (10)

Assembly (50, 100) for a turbomachine comprising a compressor shaft (56) (54) and a fan disc (70) (52),
the compressor shaft (56) extending along a longitudinal axis (B), the fan disc (70) being mounted on the compressor shaft (56) around said longitudinal axis (B),
in which the compressor shaft (56) comprises a radially outer surface (56-1) comprising a first part (58) comprising a plurality of main splines (68) and a second part (60),
the fan disk (70) comprising a radially internal surface (76-2) comprising a first part (78) comprising a plurality of complementary grooves (88) cooperating with said main grooves (68) to ensure the rotational connection of the disk ( 70) of the fan and the compressor shaft (56), and a second part (80) bearing on the second part (60) of the compressor shaft (56),
in which the second part (80) of the compressor shaft and the second part (60) of the fan disk are frustoconical,
the assembly (50, 100) further comprising a wedge (90), the compressor shaft (56) bearing substantially axially on a first side of the wedge (90), the fan disc (70) coming resting substantially axially on a second side of the wedge (90) opposite said first side. Assembly (50, 100) according to claim 1, in which the wedge (90) is arranged radially around the compressor shaft (56) and bears substantially axially on a downstream end portion of the disk (70) of blower. Assembly (50, 100) according to one of the preceding claims, in which the wedge (90) is elastically deformable. Assembly (50, 100) according to one of the preceding claims, further comprising a nut (84) configured to exert a substantially axial force on at least one of the compressor shaft (56) or the disc (70). fan so as to maintain the substantially axial support of the compressor shaft (56) and the fan disc (70) on the wedge (90). Assembly (50, 100) according to one of the preceding claims, in which the axial dimension (L2) of the second part (60) of the compressor shaft is greater than the axial dimension (L1) of the first part (58 ) of the compressor shaft, and the axial dimension (L4) of said second part (80) of the fan disk (70) is greater than the axial dimension (L3) of the first part (78) of the disk (70) of blower. Assembly (50, 100) according to one of the preceding claims, in which the second part (60) of the compressor shaft and the second part (80) of the fan disk form an angle with the longitudinal axis (B) of the compressor shaft (58) between 15° and 50°, preferably between 20° and 40°. Assembly (50) according to one of the preceding claims, wherein said first part (58) of the compressor shaft (56) and said first part (78) of the fan disk (70) are cylindrical. Assembly (100) according to one of claims 1 to 6, wherein said first part (58) of the compressor shaft (56) and said first (78) part of the fan disk (70) are frustoconical. Assembly (100) according to the preceding claim, wherein said first portion (58) of the compressor shaft (56) and said first portion (78) of the fan disc (70) form an angle with the longitudinal axis (B ) substantially equal to the angle formed by said second part (60) of the compressor shaft (56) and said second part (80) of the fan disc (70) with said longitudinal axis (B). Assembly (50, 100) according to one of the preceding claims, wherein said first part (58) of the compressor shaft and said first part (78) of the fan disk are arranged respectively upstream of said second part (60). ) of the compressor shaft and said second part (80) of the fan disk.