Turbine rotor for a turbomachine and method for mounting the rotor

Abstract

The invention relates to a turbine rotor (20) comprising a disc (30) having cavities (31), a plurality of blades (40) each having a root (80) housed in one of the cavities, and axial retention means comprising a first series and a second series of strips (101-104) distributed circumferentially around an axis of the rotor, the first series and the second series of strips being axially superposed and arranged so that at least two strips (101, 103) of the first series circumferentially adjacent are axially superposed on strips (102, 104) of the second series, and each of the strips of the first series and of the second series is arranged opposite a cavity of the disc so as to axially block the root of a blade.

Description

Technical Field

[0001] The present invention relates to the general field of turbomachines.

[0002] The invention relates more particularly to a high-pressure or low-pressure turbine rotor and to a turbomachine comprising such a rotor. The invention also relates to a method for mounting such a rotor. Background Art

[0003] An aircraft turbomachine typically consists of several modules, such as a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine followed by a low-pressure turbine, and a gas injection system. The low-pressure turbine and the high-pressure turbine drive the corresponding low-pressure compressor or high-pressure compressor. Each turbine is formed by one or more stages, each of which in turn comprises a wheel of stationary blades called guide vanes and a wheel of moving blades called a rotor.

[0004] In this application, the terms "outer" and "inner," "upper" and "lower," "outer side" and "inner side" are used with reference to the position of a part or surface relative to the longitudinal axis of the turbine. Furthermore, the terms "radial" and "axial" correspond to the axial direction, which is parallel to the longitudinal axis of the turbine, and to the radial direction, i.e., perpendicular to the longitudinal axis of the turbine, respectively. Furthermore, the terms "upstream" and "downstream" are used with reference to the flow direction of the gas flow in the turbine, as indicated by the arrows in the figures.

[0005] Figure 1 is an axial cross-sectional view of a portion of a turbine rotor according to the prior art, the cross-sectional view being taken at one of the blade roots mounted circumferentially around the rotor disk.

[0006] Reference Figure 1 The stationary blades 11 of the guide vanes are connected together at their radially inner ends by annular sectors placed circumferentially end to end so as to form an inner shroud 12 and are mounted at their radially outer ends on a casing (not shown) of the turbine.

[0007] Furthermore, the rotor comprises a disk 3 comprising, at its outer periphery, teeth delimiting slots in which the moving blades 4 engage by their respective roots 8. Each moving blade 4 comprises a blade 5 equipped with a platform 6 connected to a support extending radially to the root 8. The roots 8 of the moving blades 4 are retained radially in the slots of the disk 3 by their spherical sections (called dovetail sections) and axially by an annular ring 14 axially abutting against the upstream face of the roots 8 of the moving blades 4. The annular ring 14 is radially retained in an upstream groove 6 c formed on the inner face of the platform 6 and is axially retained by an annular upstream clamp 15 fixed to the disk 3.

[0008] In order to improve the performance of the turbine and to prevent the disk 3 from overheating due to the flow of hot gases from the upstream combustion chamber and the flow stream 9 flowing through the turbine, it is important to limit as much as possible the circulation of these gases radially from the outside to the inside, that is, from the flow 9 to the area 10 located between the platforms 6 of the blades 4 and the disk 3. In fact, the part of the gas flow 9 that flows radially under the platform 6 does not contribute to the rotation of the blades 40 and directly heats the teeth of the disk 3. In addition, the cooling of the disk 3 and the roots 8 of the blades 4 is ensured by ports (not shown) provided in the upstream clamp 15, which ensure the path of the cooling air flow towards the bottom of the slots in the disk 3. Therefore, it is also necessary to limit the passage of the cooling air flow radially from the inside to the outside.

[0009] In order to limit the gas circulation between the flow 9 and the zone 10 situated between the platform 6 of the moving blades 4 and the disk 3, it is known to equip the platform 6 of each moving blade 4 with an upstream spoiler 6a and a downstream spoiler 6b defining a sealing baffle with a downstream spoiler 13b and an upstream spoiler 13a, respectively, formed axially projecting on annular sectors of the inner shroud 12 situated respectively upstream and downstream of the rotor.

[0010] Furthermore, the sealing between the platforms 6 is ensured by sealing plates 18 (also called "lollipops") installed between the moving blades 4 in side cavities 19 provided in the pillars 7 of the moving blades 4. In particular, each sealing plate 18 is installed between two circumferentially adjacent moving blades 4 and comprises a circumferential end portion housed in the side cavity 19 of the moving blade 4 and an opposite circumferential end portion housed in the side cavity 19 of the adjacent moving blade 4. These sealing plates 18 closely fit the internal shape of the side cavity 19 with a small gap. In operation, these sealing plates 18 are subjected to centrifugal forces and are radially pressed against the inner face of the main wall of the platform 6, thereby preventing hot gases from flowing radially through the region 10 located radially below the platform.

[0011] Furthermore, each moving blade 4 includes an upstream lower wall 16 a and a downstream lower wall 16 b extending radially between the root 8 and the platform 6 of each moving blade 4, which surround and limit the bypass of the gas flow in the inflow 9. Furthermore, the upstream lower wall 16 a and the downstream lower wall 16 b limit the leakage of gas from the flow 9 that wants to bypass the moving blade 4 by passing through the root 6 of the moving blade 4.

[0012] Furthermore, in addition to ensuring the sealing in the turbine, the reduction of the mass of the constituent elements of the turbine is a constant concern, which has led to the development of blades the vanes of which are made of ceramic matrix composite materials known as CMCs.

[0013] While the use of CMC materials makes it possible to reduce the weight of blades and increase their resistance to high temperatures, it also requires evaluating the geometry of the moving blade 4 due to limitations in the methods used to manufacture CMC parts. In practice, manufacturing a moving blade equipped with a platform having a structure similar to that described above is complex, as such a structure can, in particular, create problems with material fiber distortion during its manufacture. Of course, this problem of simplified platform structures can also arise in other types of blades. Summary of the Invention

[0014] The present invention provides a solution to the above-mentioned problems by providing a turbine rotor comprising blades made of, for example, CMC, the structure of which is simplified and sealing is ensured.

[0015] A first aspect of the invention relates to a turbine rotor extending about an axis and comprising:

[0016] a disk centered on the axis of the rotor and comprising slots and teeth in its outer periphery, the slots being distributed circumferentially around the disk and each tooth being delimited by two circumferentially adjacent slots,

[0017] - a plurality of blades, each blade comprising:

[0018] - blades extending radially with respect to the rotor axis,

[0019] - a root, provided in the radial extension of the blade, configured to be mounted in a corresponding slot of the disk,

[0020] - platform, located between the blade and the root of the blade,

[0021] wherein the disk comprises axial retaining means configured to axially retain the roots of the blades in the slots of the disk, the axial retaining means comprising a first series of lamellae and a second series of lamellae distributed circumferentially around the axis, the lamellae of the first series and the lamellae of the second series being axially superposed and arranged such that:

[0022] - at least two circumferentially adjacent lamellae of the first series are axially superposed on the lamellae of the second series and are circumferentially offset,

[0023] Each lamella of the first and second series is arranged facing a slot of the disk so as to axially block the root of a blade mounted in said slot of the disk.

[0024] By replacing the annular ring with a first and a second series of lamellae, the axial retention of the blades and the sealing between the blades are ensured by the overlap of the lamellae of the first series with the lamellae of the second series, which makes it possible to eliminate the upstream and downstream lower walls. This elimination of the upstream and downstream lower walls makes it possible to reduce the height of the struts and therefore the mass of the blades.

[0025] Furthermore, due to the axial superposition of the lamellae of the first and second series, such axial retaining means are mechanically more resistant than annular rings to the stresses exerted by the hot gases during operation of the rotor.

[0026] Furthermore, replacing the annular ring with the first and second series of lamellae reduces the problem of differential expansion between the axial retaining device and the blades during rotor operation. In fact, the increase in the total volume of the lamellae due to thermal expansion is smaller than the increase in the total volume of the annular ring. Similarly, the lamellae are less likely to exert stress on adjacent components, namely, adjacent lamellae and the blade platform, thus limiting deformation or even fracture of these components during rotor operation.

[0027] Furthermore, the smaller lamellae are easier to install and remove than the annular rings. Furthermore, maintenance of the rotor is facilitated, as it is sufficient to replace only the degraded lamellae, rather than the entire annular ring.

[0028] Furthermore, thin sheets are easier to manufacture than annular rings, in particular because thin sheets are easier to size than annular rings.

[0029] In addition to the features mentioned immediately above, the turbine rotor according to the first aspect of the invention may have one or more complementary features of the following features considered individually or in all technically possible combinations.

[0030] According to a non-limiting embodiment, each blade comprises a strut situated between the root and the platform of said blade and having an upstream face and a downstream face, and wherein the lamellae of the first and second series have a substantially T-shaped shape, each of said lamellae comprising:

[0031] a radially outer portion configured to face one face of at least two circumferentially adjacent struts or to face at least two circumferentially adjacent lamellae (101, 102, 103),

[0032] - a radially inner portion configured to face the root of the blade.

[0033] According to a non-limiting embodiment, the lamellae of the first and second series comprise upstream lamellae mounted upstream of the disc, the lamellae of the first and second series being axially superimposed and arranged such that:

[0034] - at least two circumferentially adjacent upstream lamellae of the first series are axially superposed on the upstream lamellae of the second series, and,

[0035] Each upstream lamella of the first and second series is arranged facing a slot of the disk so as to axially block the root of a blade mounted in said slot of the disk.

[0036] According to a non-limiting embodiment, the axial retention means comprise an annular upstream clamp which is fixed on the one hand to the disc and which, on the other hand, retains the upstream lamellae of the first and second series against the disc.

[0037] According to a non-limiting embodiment, the upstream holder has an upstream edge that extends axially to the annular upstream spoiler. Thus, the upstream spoiler of the platform of the moving blade is transferred to the upstream holder, which simplifies the structure of the platform of the moving blade and thus facilitates its production, which is particularly interesting when the blade is made of a ceramic matrix material.

[0038] According to a non-limiting embodiment, the platform of each blade comprises a main wall having an upstream edge, each upstream lamella of the first and second series bearing radially against at least one inner face of the upstream edge.

[0039] According to a non-limiting embodiment, the lamellae of the first and second series comprise downstream lamellae mounted downstream of the disc, the lamellae of the first and second series being axially superimposed and arranged such that:

[0040] - at least two circumferentially adjacent downstream lamellae of the first series are axially superposed on the downstream lamellae of the second series, and,

[0041] Each downstream lamella of the first and second series is arranged facing a slot of the disk so as to axially block the root of a blade mounted in said slot of the disk.

[0042] According to a non-limiting embodiment, the axial retaining means comprise radially inner and radially outer retaining means configured to retain axially and radially the first and second series of downstream lamellae facing the slots of the disc.

[0043] According to a non-limiting embodiment, the radially inner retaining means are formed by radial hooks of the disc, each radial hook extending radially from the downstream face of a tooth of the disc and configured to house the circumferential end of a radially outer portion of a downstream foil.

[0044] In a non-limiting embodiment, the radially outer retaining means are formed by radial grooves formed in the platform of the blade, each radial groove being provided in the inner face of the downstream edge of the platform and configured to house a radially outer portion of a downstream foil.

[0045] According to a non-limiting embodiment, the blades and the lamellae are made of different materials.

[0046] According to a non-limiting embodiment, the blade is made of a ceramic matrix material.

[0047] According to a non-limiting embodiment, the sheet is made of a metallic material.

[0048] A second aspect of the invention relates to a turbomachine comprising at least one turbine rotor according to the first aspect.

[0049] A third aspect of the present invention relates to a method for installing a turbine rotor according to the first aspect of the present invention, the method comprising the following steps:

[0050] - insert the root of the blade into the slot of the disc,

[0051] - positioning the lamellae of the first and second series so that at least two circumferentially adjacent lamellae of the first series are axially superposed on a lamellae of the second series and each lamella of the first and second series is arranged facing a slot of the disk so as to axially block the root of a blade mounted in said slot of the disk.

[0052] The invention and its various applications will be better understood by reading the following description and examining the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings are set forth by way of illustration and are not in any way limiting.

[0054] Figure 1 is an axial cross-sectional view of a portion of a turbine rotor according to the prior art, the cross-sectional view being taken at the roots of blades mounted in slots of a rotor disk.

[0055] Figure 2 is a partial axial cross-sectional view of a turbine of a turbomachine.

[0056] Figure 3 is an axial cross-sectional view of a portion of a rotor according to one embodiment of the present invention, the axial cross-sectional view being taken at the root of a blade mounted in a slot of a rotor disk.

[0057] Figure 4 is viewed from the downstream of the turbine. Figure 3 A perspective view of the rotor shown in FIG.

[0058] Figure 5is viewed from upstream of the turbine. Figure 3 A perspective view of the rotor shown in FIG. DETAILED DESCRIPTION

[0059] Unless otherwise specified, identical elements appearing in different figures have a single reference number.

[0060] The invention relates to a rotor 20 for a turbine 1 of a turbomachine.

[0061] It should be noted that a turbine generally includes, from upstream to downstream in the direction of gas flow, a fan, one or more compressor stages, such as a low-pressure compressor and a high-pressure compressor, a combustion chamber, one or more turbine stages, such as a high-pressure turbine and a low-pressure turbine, and an exhaust nozzle.

[0062] Figure 2 It is a partial axial cross-section of the high-pressure or low-pressure turbine of a turbomachine.

[0063] Reference Figure 2 , the turbine 1 comprises a plurality of blade stages, each stage comprising a wheel of fixed blades 110 (called guide vanes) and a wheel 20 of moving blades 40 (called rotor).

[0064] The wheel of stationary blades 110 is mounted via its radially outer ends to an outer casing 111 of the turbine 1 and is connected together at its radially inner ends by annular sectors of an inner shroud 112 placed circumferentially end to end and carrying blocks of abradable material.

[0065] The wheels 20 of moving blades 40 are axially assembled to one another by annular flanges and each wheel comprises a disk 30 carrying an individual moving blade 40. The rotor 20 is connected to the shaft of the turbine 1 via a drive cone 10.

[0066] In operation, the stationary blades 110 of the guide vanes and the moving blades 40 of the rotor 20 are exposed to the hot gases in the flow from the combustion chamber into the turbine 1 .

[0067] In the following description, the term "blade" will be used to refer to the rotor moving blades.

[0068] Figure 3 is an axial cross-sectional view of a portion of a rotor 20 according to one embodiment of the present invention, the axial cross-sectional view being taken at the root of a blade mounted in a slot 31 of a disk 30 of the rotor 20 of the turbine 1 .

[0069] Reference Figure 3 Each blade 40 comprises a blade 50 connected by a platform 60 to a mid-section or strut 70 extending radially to a root 80 .

[0070] As in Figure 4 and Figure 5 As can be seen in FIG, the roots 80 of the blades 40 engage in slots 31 provided in the outer periphery of the disk 30. The slots 31 are regularly distributed around the axis of rotation X of the rotor 20 and define teeth 32 between them.

[0071] Furthermore, each platform 60 includes a main wall bounded by an upstream edge 61, a downstream edge 62, and two circumferential edges 64. To limit gas leakage through the gaps between the circumferential edges 64 of the platforms 60, each blade 40 includes two side cavities 71 disposed within the struts 70. Sealing members 90, referred to as "lollipops," are positioned within the side cavities. Each sealing member 90 is mounted between two circumferentially adjacent blades 40 and includes a circumferential end portion received within the side cavity 70 of the blade 40, and an opposing circumferential end portion received within the side cavity 71 of the circumferentially adjacent blade 40. These sealing members 90 are formed from plates that closely conform to the internal shape of the side cavities 71 with a small clearance. During operation, these sealing members 90 are subjected to centrifugal forces and are radially pressed against the inner surfaces of the side cavities 71, preventing hot gases from the flow from radially passing through the region between the platform 60 and the disk 30. These sealing members 90 also provide damping for vibrations to which the blades 40 are subjected during operation.

[0072] The roots 80 of the blades 40 are retained radially in the slots 31 by their spherical sections, called dovetail sections. Furthermore, the roots 80 of the blades 40 are retained axially in the slots 31 of the disk 30 by axial retaining means.

[0073] The axial retention means comprise upstream lamellae 101 , 102 arranged upstream of the disc 30 and an upstream clamp 97 which retains said upstream lamellae 101 , 102 against the disc 30 .

[0074] The upstream clamping member 97 is fixed to the disk 30 of the rotor 20 and is in the form of a rotating member whose axis of rotation is identical to the axis of rotation X of the rotor 20 .

[0075] The upstream clamp 97 has an upstream edge 97 - 1 which extends axially to an annular upstream spoiler 97 - 2 which defines a sealing baffle with the downstream spoiler 113 b . Figure 2As can be seen in FIG, the downstream spoiler is arranged in an annular sector of the inner shroud 112 located upstream of the rotor 20. The overlap of the upstream spoiler 97-2 arranged in the upstream clamp 97 and the downstream spoiler 113b arranged in the inner shroud 112 limits the passage of hot gas radially from the outside to the inside, that is, from the annular flow of the hot gas flow to the area between the platform 60 and the disk 30 of the blade, and conversely limits the flow of cold air radially from the inside to the outside. In addition, the downstream edge 62 of the main wall of the platform 60 extends axially to the downstream spoiler 62-1, which defines a sealing baffle with the upstream spoiler 113a. Figure 2 As can be seen in FIG, the upstream spoiler is arranged in an annular sector of the inner shroud 112 situated downstream of the rotor 20 .

[0076] Furthermore, the upstream clamp 97 has a downstream edge 97 - 3 bearing axially against the disk 30 and facing the upstream face of the root 80 of the blade 40. Advantageously, the upstream clamp 97 comprises sealing means formed by an O-ring 98 arranged between the upstream clamp 97 and the disk 30, in an annular groove 97 - 5 arranged in the radially inner portion of the downstream edge 97 - 3 of the upstream clamp 97.

[0077] Furthermore, in order to maintain the upstream lamellae 101, 102 axially and radially against the disk 30, the upstream clamp 97 comprises an annular shoulder 97-4 provided in the radially external portion of its downstream edge 97-3. Advantageously, the annular shoulder 97-4 forms radial and axial bearing surfaces defining a housing for housing the upstream lamellae 101, 102.

[0078] The upstream fins 101, 102 are arranged facing the slots 31 of the disk 30 so as to axially block the roots 80 of the blades 40 in said slots 31. Furthermore, each fin 101, 102 has a radially inner end bearing radially against the radial bearing surface formed by the annular shoulder 97-4 and a radially outer end bearing radially against the inner face of the upstream rim 61 of the platform 60.

[0079] The upstream lamellae 101, 102 include a first series and a second series that are circumferentially distributed and axially superimposed about the axis X of the rotor 20. Specifically, the upstream lamellae 101 of the first series are positioned between the axial support surface formed by the annular shoulder 97-4 of the upstream clamp 97 and the upstream face of the upstream lamellae 102 of the second series. The upstream lamellae 102 of the second series are positioned between the upstream face of the strut 70 and the downstream face of the upstream lamellae 101 of the first series. Furthermore, the first and second series of upstream lamellae 101, 102 are arranged such that at least two adjacent upstream lamellae 101 of the first series are axially superimposed on the upstream lamellae 102 of the second series. In other words, the upstream lamellae 101 of the first series overlap (i.e., are circumferentially offset) with the upstream lamellae 102 of the second series to limit gas leakage through the gap between two circumferentially adjacent upstream lamellae.

[0080] Advantageously, the first and second series of upstream lamellae 101 , 102 have a generally T-shaped shape.

[0081] The heads 101-1 or radially outer portions of the upstream lamellae 101, 102 are configured to face the upstream faces of at least two circumferentially adjacent struts 70, or the upstream faces of at least two circumferentially adjacent upstream lamellae 101, 102. In particular, the heads 101-1 of the upstream lamellae 101 of the first series axially bear against the upstream faces of at least two circumferentially adjacent upstream lamellae 102 of the second series. The heads 102-1 of the upstream lamellae 102 of the second series axially bear against the upstream faces of at least two circumferentially adjacent struts 70.

[0082] Furthermore, the roots 101-2, 102-2 or radially inner portions of the first and second series of upstream lamellae 101, 102 face at least one root 50 of a blade 40 mounted in a slot 31 of the disk 30. Furthermore, the roots 101-2, 102-2 of the first and second series of upstream lamellae 101, 102 form lugs for rotationally blocking said upstream lamellae 101, 102. In particular, the roots 101-2, 102-1 of the first and second series of upstream lamellae 101, 102 circumferentially abut against the upstream edge 32-1 of the tooth 32 of the disk 30.

[0083] Furthermore, the axial retaining means comprise downstream lamellae 103 , 104 arranged downstream of the disk 30 , and radially outer and inner retaining means for retaining said downstream lamellae 103 , 104 radially and axially facing the slots 31 of the disk 30 .

[0084] Advantageously, the radially outer retaining means are formed by radial grooves 62-2 provided in the inner face of the downstream rim 62 of the platform 60. Thus, when the platforms 60 are arranged circumferentially end to end, the radial grooves 62-2, placed end to end, form an annular radial groove. Furthermore, the radially inner retaining means are formed by radial hooks 33 extending radially from the downstream face of each tooth 32 of the disk 30. Thus, the head 103-1, 104-1 of each downstream lamella 103, 104 is retained at its radially outer end by at least one radial groove 62-2 and at its radially inner end by at least two adjacent radial hooks 33.

[0085] Furthermore, similar to the upstream lamellae 101 and 102, the downstream lamellae 103 and 104 are arranged facing the slots 31 of the disk 30 so as to axially block the roots 80 of the blades 40 in the slots 31. Furthermore, the downstream lamellae 103 and 104 comprise a first series and a second series distributed circumferentially about the axis X of the rotor 20. Furthermore, the downstream lamellae 103 of the first series and the downstream lamellae 104 of the second series are axially superimposed. In particular, the downstream lamellae 104 of the second series are positioned between the downstream faces of the struts 70 of the blades 40 and the upstream faces of the downstream lamellae 103 of the first series. Furthermore, the downstream lamellae 103 and 104 of the first series are arranged such that at least two circumferentially adjacent downstream lamellae 103 of the first series are axially superimposed on the downstream lamellae 104 of the second series. In other words, the first series of downstream lamellae 103 overlap (ie are circumferentially offset) with the second series of downstream lamellae 104 in order to limit gas leakage through the gap between two circumferentially adjacent downstream lamellae.

[0086] Advantageously, the first and second series of downstream lamellae 103 , 104 have a generally T-shaped shape.

[0087] The heads 103-1 or radially outer portions of the downstream lamellae 103, 104 are configured to face the downstream faces of at least two circumferentially adjacent struts 70, or the downstream faces of at least two circumferentially adjacent downstream lamellae 103, 104. In particular, the heads 103-1 of each downstream lamella 103 of the first series bear axially against the downstream faces of at least two downstream lamellae 104 of the second series, while the heads 104-1 of each downstream lamella 104 of the third series bear axially against the downstream faces of at least two struts 7. Each head 103-1, 104-1 of the first and second series of downstream lamellae 103, 104 bears radially against two adjacent radial hooks 33.

[0088] Furthermore, the roots 103-2, 104-2 of the first and second series of downstream lamellae 103, 104 are positioned between two adjacent radial hooks 33, facing the root 80 of the blade 40. Thus, the root 103-2, 104-2 of each said downstream lamella 103, 104 forms a lug that abuts circumferentially against the radial hooks 33 of the disk 30 so as to rotationally block said downstream lamellae 103, 104.

[0089] Advantageously, the upstream clamp 15 and / or the upstream fins 101, 102 and / or the downstream fins 103, 104 comprise ports (not shown) which ensure the path of the cooling air flow indicated by the arrows towards the bottom of the slots of the disk 3 in order to ensure cooling of the disk 30 and the roots 80 of the moving blades 40.

[0090] Advantageously, the blades 40 and the upstream and downstream lamellae 101, 102, 103, 104 are made of different materials. Thus, for example, the blades 40 are made of a ceramic matrix composite material, while the upstream and downstream lamellae 101, 102, 103, 104 are made of a metallic material, for example. In an alternative embodiment, the blades 40 and the lamellae 101, 102, 103, 104 are made of the same material, for example a material of the ceramic matrix composite type.

[0091] The present invention also relates to a method for installing the rotor 20 described above.

[0092] In a first step, the sealing member 90 is positioned in the side cavity 71 provided in the strut 70 of the blade 40 .

[0093] In a second step, the root 80 of the blade 40 is partially inserted into the slot 31 of the disk 30 , preferably over more than half the width of the disk 30 .

[0094] In a third step, the first and second series of downstream lamellae 103, 104 are positioned inside the radial hooks 33. In particular, the downstream lamellae 103, 104 are arranged so that their heads 103-1, 104-1 are held by two adjacent radial hooks 33 and their roots 103-2, 104-2 are positioned between these two radial hooks 33. Furthermore, the first and second series of downstream lamellae 103, 104 are axially superimposed so that at least two circumferentially adjacent downstream lamellae 103 of the first series are axially superimposed on the downstream lamellae 104 of the second series.

[0095] In a fourth step, the first and second series of downstream lamellae 103 , 104 are placed obliquely in the radial hooks 33 so as to bring the radially outer ends of said lamellae 103 , 104 closer to the downstream edge 62 of the platform 60 of the blade 40 .

[0096] In a fifth step, the root 80 of the blade 40 is fully inserted into the slot 31 of the disk 30 and the radially outer ends of the first and second series of downstream lamellae 103 , 104 are positioned in the radial grooves 62 - 1 provided in the downstream edge 62 of the platform 60 of the blade 40 .

[0097] In a sixth step, the first and second series of upstream lamellae 101, 102 are placed in the housing formed by the annular shoulder 94-4 of the upstream clamp 97. Specifically, the first and second series of upstream lamellae 101, 102 are arranged so that at least two circumferentially adjacent upstream lamellae 101 of the first series are axially superposed on the upstream lamellae 102 of the second series. The heads 101-1 of the upstream lamellae 101 of the first series then bear axially against the upstream faces of at least two circumferentially adjacent upstream lamellae 102 of the second series, while the heads 102-1 of the upstream lamellae 102 of the second series bear axially against the upstream faces of at least two circumferentially adjacent struts 7. Furthermore, the roots 101-2, 102-2 of the first and second series of upstream lamellae 101, 102 circumferentially abut against the upstream edges 32-1 of the teeth 32 of the disk 30.

[0098] In a seventh step, the upstream clamping piece 97 is fixed to the upstream flange of the disk 30 of the rotor 20 so that the radially outer ends of the first and second series of upstream lamellae 101, 102 radially bear against the inner face of the upstream rim 61 of the platform 60 and so that the radially inner ends of the first and second series of upstream lamellae 101, 102 radially bear against the radial bearing surface formed by the annular shoulder 97-4 of the upstream clamping piece 97.

[0099] Of course, the invention is not limited to the different embodiments described and alternative embodiments are possible.

Claims

1. A turbine rotor extending about an axis and comprising: - a disc centered on the axis and comprising slots and a plurality of teeth provided in the outer periphery of the disc, the slots being distributed circumferentially around the disc and each tooth being delimited by two circumferentially adjacent slots, - Multiple blades, each blade comprising: o blades, extending radially relative to the axis, o roots, formed in the radial extension of the blade, configured to fit in corresponding slots of the disk, o Platform, located between the blade and the root of the blade, o wherein the disk comprises axial retaining means configured to retain the roots of the blades axially in the slots of the disk, Characterized in that the axial retaining means comprise a first series of lamellae and a second series of lamellae distributed circumferentially around the axis, the lamellae of the first series and the lamellae of the second series having a generally T-shaped shape and being axially superposed and arranged such that: - at least two lamellae of the first series are circumferentially adjacent to one another and at least two lamellae of the second series are circumferentially adjacent to one another, - the upper portion of each T-shape of at least two circumferentially adjacent lamellae of the first series axially superposes the upper portion of each T-shape of at least two circumferentially adjacent lamellae of the second series and is circumferentially offset; Each lamella of the first and second series is arranged facing a slot of the disk so as to axially block the roots of a plurality of blades mounted in said slot of the disk.

2. The turbine rotor according to claim 1, characterized in that Each blade comprises a strut located between the root and the platform of the blade and having an upstream face and a downstream face, and the first and second series of lamellae have a generally T-shaped shape, each of the lamellae comprising: - a radially outer portion configured to face one face of at least two circumferentially adjacent struts, or to face at least two circumferentially adjacent lamellae, - a radially inner portion configured to face the root of the blade.

3. The turbine rotor according to claim 1, characterized in that The first series of lamellae and the second series of lamellae comprise upstream lamellae mounted upstream of the disc, the first and second series of upstream lamellae being axially superimposed and arranged such that: - at least two circumferentially adjacent upstream lamellae of the first series are axially superposed on the upstream lamellae of the second series, and, - each upstream lamella of the first and second series is arranged facing a slot of the disc so as to axially block the root of a blade mounted in said slot of the disc, The axial retaining means comprise an annular upstream clamp which is fixed to the disc on the one hand and which retains the upstream lamellae of the first and second series against the disc on the other hand.

4. The turbine rotor according to claim 3, characterized in that The platform of each blade comprises a main wall having an upstream edge, each upstream lamella of the first and second series bearing radially against at least one inner face of the upstream edge.

5. The turbine rotor according to claim 1, characterized in that The first and second series of lamellae comprise downstream lamellae mounted downstream of the disc, the first and second series of downstream lamellae being axially superimposed and arranged such that: - at least two circumferentially adjacent downstream lamellae of the first series are axially superposed on the downstream lamellae of the second series, and, Each downstream lamella of the first and second series is arranged facing the slot of the disc so as to axially block the root of a blade mounted in the slot of the disc.

6. The turbine rotor according to claim 5, characterized in that The axial retaining means comprise radially inner and radially outer retaining means configured to retain axially and radially the first and second series of downstream lamellae facing the slots of the disc.

7. The turbine rotor according to claim 6, characterized in that The radially inner retaining means are formed by radial hooks of the disc, each radial hook extending radially from the downstream face of a tooth of the disc and configured to house the circumferential end of a radially outer portion of a downstream foil.

8. The turbine rotor according to any one of claims 6 to 7, characterized in that The radially outer retaining means are formed by radial grooves formed in the platform of the blade, each radial groove being provided in the inner face of the downstream edge of the platform and being configured to house a radially outer portion of a downstream foil.

9. The turbine rotor according to claim 1, characterized in that The blades and flakes are made of different materials.

10. The turbine rotor according to claim 9, characterized in that The blades are made of a ceramic matrix material, and the sheets are made of a metal material.

11. A method for installing a rotor of a turbine according to any one of claims 1 to 10, characterized in that: The method comprises the following steps: - Insert the root of the blade into the slot of the disc, - positioning the lamellae of the first series and the lamellae of the second series so that at least two circumferentially adjacent lamellae of the first series are axially superposed on the lamellae of the second series and so that each lamellae of the first and second series is arranged facing a slot of the disk so as to axially block the root of a blade mounted in said slot of the disk.

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