PROTECTIVE ELEMENT FOR A COMPRESSOR Drum AND METHOD FOR SERVICING A COMPRESSOR Drum

Abstract

The invention relates to a protective element (45.1, 45.2) for a compressor drum (20), intended to be arranged at least partially between a blade root (25) and the compressor drum (20), comprising: a first side wall (51.1, 51.2) comprising an inner portion (54.1, 54.2) for covering an inner circular portion of a pocket (24); the compressor drum (20) comprises a plurality of blades (5.1, 5.2), a bearing surface portion (55.1, 55.2) for covering a blade root bearing surface of the pocket (24), and an outer portion (56.1, 56.2) for covering an outer circular portion of the compressor drum (20); a connecting wall (53.1, 53.2) for covering an outer face of the compressor drum (20); and a second side wall (52.1, 52.2) comprising a protruding portion (57.1, 57.2) for engaging with a mounting groove (46.1, 46.2) formed in a vertical face of the compressor drum (20).

Description

Technical Field

[0001] This invention relates to a protective element for a low-pressure compressor drum used in a turbine. The invention reveals a particularly advantageous application for repairing worn low-pressure compressor drums. However, the invention can also be implemented with low-pressure compressor drums under new conditions at the end of production. Background Technology

[0002] The working principle of a turbofan is to compress the air entering the engine. Most of this air forms the secondary flow, while another part forms the primary flow. This primary flow passes through a low-pressure compressor integrated with the fan, a high-pressure compressor, a combustion chamber, a high-pressure turbine, and finally a low-pressure turbine before being injected.

[0003] Fan compression occurs in two stages. In the first stage, the moving blade assembly provides acceleration to the air particles by deflecting them relative to the engine axis. This moving blade assembly comprises multiple blades mounted on a cylindrical hub called a "fan disk," which is driven to rotate by a low-pressure turbine.

[0004] In the second stage, a stationary fan assembly slows down air particles and converts a portion of their velocity into pressure. This stationary fan assembly is called an OGV (“Outlet Guide Vane”) or “rectifier” because it directs the airflow accelerated by the moving fan assembly back along the engine’s axis.

[0005] The same principle applies to the low-pressure compressor downstream of the fan. The low-pressure compressor consists of moving blades mounted on a cylindrical section called the compressor drum, and a rectifier composed of fixed blades. Depending on the turbine, the low-pressure compressor can have 3 to 5 stages, with each compressor stage consisting of a wheel with moving blades and a corresponding rectifier grid.

[0006] like Figure 1 As shown, for each stage of the low-pressure compressor, the movable blades 1 are installed in the corresponding unit 2 of the compressor drum 4 through the introduction window 3 according to the following steps:

[0007] i - Insert the first blade 1 into the unit 2 by introducing window 3 along arrow F1.

[0008] ii - Once blade 1 is inserted, it is tangentially moved along arrow F2 by sliding it into unit 2 to clear the entry window 3. Then the first blade 1 is installed.

[0009] iii - Then the next blade can be inserted, and the operation is repeated until all blades 1 are installed in unit 2.

[0010] As the turbine and therefore the compressor drum 4 rotate, the movable blades 1 are radially held by the support area 5 in unit 2, such as Figure 2 As shown. The installation process for mounting the movable blade 1 into the unit 2 of the compressor drum 4 is a conventional and proven installation in the prior art.

[0011] However, at the contact surface between the support area 6 at the blade root 7 and the support area 5 in the unit 2, the minute displacement of the blade 1 within the unit 2 can locally wear down the support area 5 in the unit 2.

[0012] Depend on Figure 2 The wear, indicated by the dashed line, can reduce the radial clearance above the moving blade 1, creating a risk that the moving blade 1 may uncontrollably penetrate into the wear-resistant washer. This wear also poses a risk that the moving blade 1 may interfere with the axial misalignment of the stationary blades. Furthermore, positional differences between the moving blades 1 affect the balance of the compressor drum 4.

[0013] Because there is a risk that the movable blade 1 is located between the unworn and worn portions of the support area 5 of the compressor drum 4, it may also affect the installation of the movable blade 1 on the worn compressor drum 4.

[0014] Significant wear may also affect the mechanical strength of the low-pressure compressor drum 4, which may cause the compressor drum 4 to break during operation. Summary of the Invention

[0015] The object of this invention is to effectively remedy the above-mentioned disadvantages by providing a protective element for a compressor drum, said protective element being at least partially disposed between the blade root and the compressor drum, said protective element comprising:

[0016] A first sidewall, comprising an inner portion for covering an inner circular portion of a unit in the compressor drum, a support region portion for covering a blade root support region in the unit, and an outer portion for covering an outer circular portion of the compressor drum.

[0017] A connecting wall, the connecting wall being used to cover the outer surface of the compressor drum, and

[0018] The second sidewall includes a protrusion that cooperates with a mounting groove in the vertical surface of the compressor drum.

[0019] Therefore, this invention allows for the restoration of the contact interface between the support area and the moving blades in the drum unit. Thus, this invention allows the moving blades to be installed in the compressor drum in the same position as when they were installed on a new drum at the end of production.

[0020] According to one embodiment of the invention, the connecting wall is elastically deformable to allow the protective element to be mounted onto the compressor drum.

[0021] According to one embodiment of the invention, the protective element includes a notch arranged opposite a portion of the blade inlet window in the compressor drum.

[0022] According to one embodiment of the invention, the protective element includes at least one notch arranged opposite a portion of the blade lock introduction window.

[0023] According to one embodiment of the invention, the connecting wall includes at least one channel opening in a protruding portion of the channel region for the gasket.

[0024] According to one embodiment of the present invention, the protective element is composed of a folded metal plate with a thickness between 0.2 mm and 0.4 mm.

[0025] According to one embodiment of the present invention, the protective element is made of a nickel-based metal material.

[0026] According to one embodiment of the present invention, the support area is partially covered with a lubricating varnish layer.

[0027] According to one embodiment of the invention, the tangential length of the protective element is greater than the tangential length of the blade platform and less than or equal to the tangential length of the five blade platforms.

[0028] The present invention also relates to a method for repairing compressor drums, the method comprising the following steps:

[0029] - Machining to remove wear in the support areas of the compressor drum in order to define the unit, the unit having upstream and downstream support areas with regular surfaces.

[0030] - Two mounting grooves are machined upstream and downstream of the unit, respectively, and

[0031] - Install upstream and downstream protection elements such that the protection elements cooperate with the corresponding mounting grooves in the compressor drum and cover the upstream and downstream support areas in the unit.

[0032] According to one embodiment of the invention, the method further includes the step of machining a channel area for the gasket to have alternating protruding and flat portions, so as to facilitate mounting the protective element on the compressor drum.

[0033] According to one embodiment of the invention, each protective element is installed by applying a radial force to the protective element, causing the connecting wall of the protective element to deform so that the protrusion of each protective element cooperates with the corresponding mounting groove to cover the corresponding outer surface of the compressor drum before returning to its initial flat shape.

[0034] According to one embodiment of the present invention, the method further includes the following step: machining the outer surfaces of the compressor drum at the upstream and downstream sides of the unit, respectively. Attached Figure Description

[0035] The invention will be better understood by reading the following detailed description, and other features and advantages will be apparent. These detailed descriptions include embodiments given for illustrative purposes with reference to the accompanying drawings, which are presented by way of non-limiting example and can be used to thoroughly understand the description of the invention and its embodiments and ultimately contribute to its definition, wherein:

[0036] [ Figure 1 [Already described] Figure 1 This is a perspective view showing the blades being installed inside the unit of the low-pressure compressor drum;

[0037] [ Figure 2 [Already described] Figure 2 This is a cross-sectional view of the compressor drum unit, showing the wear in the support area caused by the blade roots;

[0038] [ Figure 3 ] Figure 3 This is a longitudinal section view of the front part of the turbine;

[0039] [ Figure 4 ] Figure 4 This is a perspective view of the drum of a low-pressure compressor that implements the maintenance method of the present invention;

[0040] [ Figure 5 ] Figure 5 This is a cross-sectional view of a unit in the drum of a low-pressure compressor that implements the maintenance method of the present invention;

[0041] [ Figure 6a ] Figure 6a This is a partial perspective view of a unit in the compressor drum after the machining steps of the maintenance method according to the present invention;

[0042] [ Figure 6b ] Figure 6b yes Figure 6a A detailed perspective view of the unit shows the machining process of the groove for receiving the washer;

[0043] [ Figure 7a ] Figure 7aThis is a perspective view of an upstream protection element for a compressor drum according to the present invention, the upstream protection element having a standard configuration;

[0044] [ Figure 7b ] Figure 7b This is a perspective view of a downstream protection element for a compressor drum according to the present invention, the downstream protection element having a standard configuration;

[0045] [ Figure 8a ] Figure 8a This is a perspective view of an upstream protection element for a compressor drum according to the present invention, the upstream protection element having a "locking" configuration;

[0046] [ Figure 8b ] Figure 8b This is a perspective view of a downstream protection element for a compressor drum according to the present invention, the downstream protection element having a "locking" configuration;

[0047] [ Figure 9 ] Figure 9 The different steps for installing the protective element according to the invention into the unit of the low-pressure compressor drum are shown;

[0048] [ Figure 10 ] Figure 10 This is a perspective view of the unit according to the invention, in which the protective element has been installed in the drum of a low-pressure compressor.

[0049] [ Figure 11 ] Figure 11 This is a perspective view showing the blades being installed into a unit in a low-pressure compressor drum that has already been fitted with a protective element according to the invention.

[0050] [ Figure 12 ] Figure 12 This is a perspective view showing the upstream and downstream protective elements according to the invention positioned between the support region of the blade and the support region of the unit in the low-pressure compressor drum.

[0051] It should be noted that, Figures 3 to 12 In the drawings, structural and / or functional elements common to different embodiments have the same reference numerals. Therefore, unless otherwise stated, these elements have the same structure, dimensions, and material properties. Detailed Implementation

[0052] In the remainder of the instruction manual, the terms “inner” and “outer” should be understood in relation to the radial direction relative to the axis X1 of the compressor drum, that is, the “inner” surface is the radially inner surface and the “outer” surface is the radially outer surface, such that the inner surface is closer to the axis X1 of the drum than the outer surface.

[0053] Figure 3The front portion of a turbine 10 is shown, which includes a fan 11 with a movable blade assembly 12 for accelerating air particles by deflecting them relative to the engine's axis. The movable blade assembly 12 includes a plurality of blades 13 mounted on a cylindrical hub 14 called a "fan disk," which is driven to rotate by a low-pressure turbine.

[0054] The fixed blade assembly 15, located downstream of the movable blade assembly 12, slows down air particles and converts a portion of their velocity into pressure. This fixed blade assembly 15 is referred to as an OGV (“outlet guide vane”) or “rectifier” because it causes the airflow accelerated by the movable blade assembly 12 to return along the engine axis.

[0055] The low-pressure compressor 18 includes movable blades 19 mounted on a cylindrical portion referred to as the low-pressure compressor drum 20, and a rectifier 21 consisting of fixed blades. Depending on the configuration of the turbine 10, the low-pressure compressor 18 may include 3 to 5 stages, each compressor stage consisting of a wheel with movable blades 19 and a corresponding grid of rectifier 21.

[0056] Figure 4 The compressor drum 20 shown has a cylindrical shape and an axis X1. The compressor drum 20 includes a plurality of units 24 corresponding to the number of stages in the low-pressure compressor 18. Each unit 24 extends along the circumference of the drum 20 and receives a circumferential groove for the blade root 25, such that the blades 19 are angularly and regularly spaced along the circumference of the compressor drum 20. The compressor drum 20 includes a mounting interface 22 for a fan hub 14.

[0057] like Figure 5 As shown, unit 24 is defined by an upstream blade root support region 26.1, an upstream inner circular portion 27.1, a unit bottom 28, a downstream inner circular portion 27.2, and a downstream blade root support region 26.2. A blade root support region 25 of corresponding shape abuts against the upstream blade root support region 26.1, and a downstream blade root support region 26.2 of corresponding shape abuts against the downstream blade root support region 26.2. In the cross-sectional view, the upstream blade root surface 26.1 and the downstream blade root surface 26.2 form a non-zero angle with respect to the unit bottom 28, such that unit 24 generally has a trapezoidal shape complementary to the shape of the blade root 25. This allows the blades 19 to be radially held in place as the compressor drum 20 rotates.

[0058] The upstream outer circular portion 29.1 and the downstream outer circular portion 29.2 are located in the extensions of the upstream blade root support region 26.1 and the downstream blade root support region 26.2 in the corresponding unit 24, respectively.

[0059] The compressor drum 20 also includes an upstream outer surface 30.1 and a downstream outer surface 30.2. The outer surfaces 30.1 and 30.2 have an annular shape oriented axially relative to the axis X1. The outer surfaces 30.1 and 30.2 are positioned radially outward from the compressor drum 20 relative to the axis X1.

[0060] The upstream vertical surface 31.1 and the downstream vertical surface 31.2 each extend in a radial plane relative to the axis X1 of the compressor drum 20. Each (upstream 31.1 and downstream 31.2) vertical surface is located on the side opposite to the corresponding surface of the outer circular portion (upstream 29.1 and downstream 29.2), the blade root support area (upstream 26.1 and downstream 26.2), and the inner circular portion (upstream 27.1 and downstream 27.2).

[0061] An upstream vertical surface 31.1, an upstream outer surface 30.1, an upstream outer circular portion 29.1, an upstream blade root support area 26.1, and an upstream inner circular portion 27.1 are formed in the upstream wall 35.1 of unit 24. A downstream vertical surface 31.2, a downstream outer surface 30.2, a downstream outer circular portion 29.2, a downstream blade root support area 26.2, and a downstream inner circular portion 27.2 are formed in the downstream wall 35.2 of unit 24.

[0062] like Figure 6a and Figure 6b As shown, the compressor drum 20 also includes an inlet window 36 for the blade root 25, and two inlet windows 37 for blade locking on either side of the inlet window 36 for the blade root 25.

[0063] Furthermore, the channel region 40 for the gasket is defined by two circumferential low walls 41 from the outer surface 30.1, between which extends a groove 42 for receiving the gasket (not shown). In the example shown, the gasket is intended to be positioned upstream of unit 24. However, depending on the stage of the low-pressure compressor 18, the gasket may be installed upstream or downstream of unit 24.

[0064] The following describes a method for repairing a worn low-pressure compressor drum 20.

[0065] The step of machining the drum 20 is performed to eliminate wear on the support regions 26.1, 26.2 of the compressor drum 20, so as to define a unit 24 having an upstream support region 26.1 and a downstream support region 26.2 with regular surfaces. Preferably, the machining process is performed such that the unit 24 has an axisymmetric structure and does not include blades or lock-in windows 36, 34.

[0066] The compressor drum 20 is also machined to allow installation in the protective elements 45.1, 45.2, which are described in more detail below. According to this operation, two mounting grooves 46.1, 46.2 are formed upstream and downstream of unit 24 in the upstream vertical surface 31.1 and the downstream vertical surface 31.2, respectively.

[0067] The upstream outer surface 30.1 and the downstream outer surface 30.2 of the low-pressure compressor drum 20 are further machined to obtain regular surfaces. In particular, the channel area 40 for the gasket is machined to form alternating protrusions 48 and flat portions 49 to facilitate the mounting of protective elements 45.1, 45.2 on the low-pressure compressor drum 20.

[0068] Once the machining steps are completed, the upstream protective element 45.1 and the downstream protective element 45.2 are installed, such that the protective elements 45.1 and 45.2 cooperate with the corresponding mounting grooves 46.1 and 46.2 in the drum 20, respectively, and respectively cover the upstream support area 26.1 and the downstream support area 26.2 in the unit 24.

[0069] Therefore, the protective elements 45.1 and 45.2 fill the gap between the support area of ​​the movable blade 19 and the support area of ​​the unit 24 in the compressor drum 20, such as Figure 12 As shown.

[0070] More specifically, each protective element 45.1, 45.2 (upstream or downstream) is designed to be arranged at least partially between the blade root 25 and the compressor drum 20.

[0071] according to Figure 7a and Figure 12 The standard upstream geometry shown includes an upstream protection element 45.1 (also referred to as an "upstream foil") comprising a first upstream sidewall 51.1, a second upstream sidewall 52.1, and an upstream connecting wall 53.1 providing a connection between the first upstream sidewall 51.1 and the second upstream sidewall 52.1.

[0072] The first upstream sidewall 51.1 includes an upstream inner portion 54.1 for covering the upstream inner circular portion 27.1 of the covering unit 24, an upstream support region portion 55.1 for covering the upstream blade root support region 26.1 in the covering unit 24, and an upstream outer portion 56.1 for covering the upstream outer circular portion 29.1 of the drum in the extension of the upstream blade root support region 26.1. The upstream support region portion 55.1 forms a non-zero angle with respect to the upstream connecting wall 53.1.

[0073] The purpose of the upstream connecting wall 53.1 is to cover the upstream outer surface 30.1 of the compressor drum 20. The upstream connecting wall 53.1 has a flat shape. The upstream connecting wall 53.1 is elastically deformable to allow the upstream protective element 45.1 to be mounted onto the compressor drum 20. The upstream connecting wall 53.1 includes at least one channel opening 60 for the protrusion 48 of the gasket channel region 40. The number of channel openings depends on the construction of the gasket channel region 40 where the upstream protective element 45.1 is located.

[0074] The second upstream sidewall 52.1 includes an upstream protrusion 57.1 for cooperating with an upstream mounting groove 46.1 in the upstream vertical surface 31.1 of the drum. The upstream protrusion 57.1 extends toward the interior of the upstream protective element 45.1. The second upstream sidewall 52.1 has an S-shaped configuration. The upstream protective element 45.1 has an axisymmetric geometry at unit 24.

[0075] Similarly, according to Figure 7b and Figure 12 The standard downstream geometry shown includes a downstream protection element 45.2 comprising a first downstream sidewall 51.2, a second downstream sidewall 52.2, and a downstream connecting wall 53.2 for connecting the first downstream sidewall 51.2 and the second downstream sidewall 52.2 to each other.

[0076] The first downstream sidewall 51.2 includes an inner downstream portion 54.2 for covering the inner circular downstream portion 27.2 of the covering unit 24, a downstream support region portion 55.2 for covering the downstream blade root support region 26.2 of the covering unit 24, and a downstream outer portion 56.2 for covering the downstream outer circular portion 29.2 of the drum 20 in the extension of the downstream blade root support region 26.2. The downstream support region portion 55.2 forms a non-zero angle with respect to the downstream connecting wall 53.2.

[0077] The downstream connecting wall 53.2 is designed to cover the downstream outer surface 30.2 of the compressor drum 20. The downstream connecting wall 53.2 has a flat shape. The downstream connecting wall 53.2 is elastically deformable for mounting the downstream protective element 45.2 onto the compressor drum 20.

[0078] The second downstream sidewall 52.2 includes a downstream protrusion 57.2 for cooperating with a downstream mounting groove 46.2 in the downstream vertical surface 31.2 of the drum 20. The downstream protrusion 57.2 extends toward the interior of the downstream protective element 45.2. The second downstream sidewall 52.2 has an S-shaped configuration. The downstream protective element 45.2 has an axisymmetric geometry at unit 24.

[0079] according to Figure 8aThe locking geometry shown includes an upstream protection element 45.1 comprising an upstream notch 63.1 arranged opposite an upstream portion of the blade inlet window 36 in the low-pressure compressor drum 20. The upstream notch 63.1 is formed in the upstream outer portion 56.1 and the upstream connecting wall 53.1 of the upstream protection element 45.1. The upstream protection element 45.1 also includes notches 64.1, each arranged opposite a portion of the blade lock inlet window 37.

[0080] Similarly, according to Figure 8b The locking geometry shown includes a downstream protection element 45.2 comprising a downstream recess 63.2 arranged opposite a downstream portion of the blade inlet window 36 in the compressor drum 20. The downstream recess 63.2 is formed in the downstream outer portion 56.2 and the downstream connecting wall 53.2 of the downstream protection element 45.2. The downstream protection element 45.2 also includes a recess 64.2 arranged opposite a portion of the blade lock inlet window 37.

[0081] Preferably, each protective element 45.1, 45.2 is constructed of a folded metal plate with a thickness between 0.2 mm and 0.4 mm. The thickness of the metal plate can be adapted to maintenance requirements to compensate for the degree of wear on the unit 24. The thin metal plate is sufficiently deformable to allow the protective elements 45.1, 45.2 to conform to the shape of the machined unit 24.

[0082] Each protective element 45.1, 45.2 is made of a nickel-based metal material, particularly a chromium-nickel-iron alloy (registered trademark). This material provides superior wear resistance compared to titanium and allows for the production of parts with low thickness and sufficient rigidity to withstand the matting stress at the interface between the moving blade 19 and the compressor drum 20.

[0083] The support areas 55.1 and 55.2 may be covered with a layer of lubricating varnish. This allows for improved contact conditions between the moving blades 19 and the corresponding support areas 26.1 and 26.2 of the unit 24, thereby maximizing the service life of the compressor drum 20.

[0084] Preferably, the tangential dimensions of the protective elements 45.1 and 45.2 allow multiple (particularly 1 to 5) movable blades 19 to contact the latter. Advantageously, the tangential lengths of the protective elements 45.1 and 45.2 are greater than the blade platform 65 (see...). Figure 11 The tangential length of the blade 19 is adjusted to prevent the support area of ​​the blade 19 from contacting the two adjacent protective elements 45.1, 45.2, thereby creating a contact interruption between the moving blade 19 and the compressor drum 20.

[0085] Furthermore, the tangential lengths of the protective elements 45.1 and 45.2 are less than or equal to the tangential lengths of the five-blade platform 65 to allow the protective elements 45.1 and 45.2 to deform for mounting onto the compressor drum 20. In fact, the greater lengths of the protective elements 45.1 and 45.2 will increase their rigidity, which will prevent them from deforming, and this is necessary for their mounting onto the compressor drum 20.

[0086] The following reference Figure 9 The steps for installing protective element 45.1 are described. Except for the installation orientation, these steps are the same as those for protective element 45.2.

[0087] As shown in the left-hand view, the protective element 45.1 is positioned according to arrow F1, such that the inner portion 54.1 and the support area portion 55.1 are respectively opposite to the inner circular portion 27.1 and the support area 26.1 of the unit 24. The connecting wall 53.1 has a flat shape before its installation.

[0088] As shown in the center view, a radial force is applied to the protective element 45.1, causing the connecting wall 53.1 to deform so that the protrusion 57.1 of the protective element 45.1 cooperates with the mounting groove 46.1.

[0089] As shown in the right-hand view, the connecting wall 53.1 then restores its initial flat shape to cover the outer surface 30.1 of the compressor drum 20. Thus, the upstream protective element 45.1 or the downstream protective element 45.2 is held around the upstream wall 35.1 or the downstream wall 35.2 of the unit 24, respectively.

[0090] like Figure 10 As shown, a plurality of upstream protective elements 45.1 are thus arranged edge-to-edge to conform to the circumference of the upstream wall 35.1 of the unit 24 in the drum. Similarly, a plurality of downstream protective elements 45.2 are arranged edge-to-edge to conform to the circumference of the downstream wall 35.2 of the unit 24 in the drum. The geometry (standard or locked) of the protective elements 45.1, 45.2 is adjusted according to the construction of the unit 24 in the implantation region for the protective elements 45.1, 45.2.

[0091] like Figure 11 As shown, based on the previous reference Figure 1 The method described above allows the blade 19 to be installed within the unit 24 via window 36. A blade lock is then implemented via window 37 to prevent movement of the blade 19 within the unit 24.

[0092] The present invention also relates to an assembly formed by protective elements 45.1, 45.2 and compressor drum 20.

[0093] Of course, different features, variations and / or embodiments of the present invention can be associated with each other in various combinations, as long as they do not contradict or exclude each other.

[0094] Furthermore, the present invention is not limited to the embodiments described above, but is provided merely as examples. The present invention includes various modifications, alternatives, and other variations that may be conceived by those skilled in the art within the context of the present invention, and in particular, any combination of the various operating modes described above may be employed individually or in combination.

Claims

1. A protective element (45.1, 45.2) for a compressor drum (20), the protective element being arranged at least partially between a blade root (25) and the compressor drum (20), wherein: The protection element comprises: a first side wall (51.1, 51.2), the first side wall comprising an inner portion (54.1, 54.2) for covering an inner circular portion (27.1, 27.2) in a unit (24) in the compressor drum (20), a bearing area portion (55.1, 55.2) for covering a blade root bearing area (26.1, 26.2) in the unit (24), and an outer portion (56.1, 56.2) for covering an outer circular portion (29.1, 29.2) of the compressor drum (20), a connecting wall (53.1, 53.2) for covering the outer surface (30.1, 30.2) of the compressor drum (20), and A second side wall (52.1, 52.2) comprising a protruding portion (57.1, 57.2) for cooperating with a mounting recess (46.1, 46.2) in a vertical face (31.1, 31.2) of the compressor drum (20).

2. The protection element according to claim 1, wherein: The connecting walls (53.1, 53.2) are elastically deformable in order to allow the protective element (45.1, 45.2) to be mounted on the compressor drum (20).

3. The protection element according to claim 1 or 2, wherein: The protection element comprises a recess (63.1, 63.2) arranged opposite a portion of a blade introduction window (36) in the compressor drum (20).

4. The protection element according to any one of claims 1 to 3, wherein: The protection element comprises at least one notch (64.1, 64.2) arranged opposite a portion of the blade lock introduction window (37).

5. The protection element according to any one of claims 1 to 4, wherein: The connecting wall (53.1, 53.2) comprises at least one passage opening (60) for a protruding part (48) of the passage region (40) of the gasket.

6. The protection element according to any one of claims 1 to 5, wherein: The protective element consists of a folded metal sheet with a thickness between 0.2 mm and 0.4 mm.

7. The protection element according to any one of claims 1 to 6, wherein: The protection element is made of nickel-based metal material.

8. The protection element according to any one of claims 1 to 7, wherein: The bearing area parts (55.1, 55.2) are covered with a lubricating varnish layer.

9. The protection element according to any one of claims 1 to 8, wherein: The tangential length of the protective element (45.1, 45.2) is greater than the tangential length of the blade platform (65) and less than or equal to the tangential length of five blade platforms (65).

10. A method for repairing a compressor drum (20), wherein: The method comprises the following steps: machining to remove wear from bearing areas (26.1, 26.2) in the compressor drum (20) so as to define a unit (24) having upstream and downstream bearing areas (26.1, 26.2) with regular surfaces, Two mounting grooves (46.1, 46.2) are machined upstream and downstream of the unit (24), respectively, and An upstream protection element (45.1) and a downstream protection element (45.2) are mounted such that the protection elements (45.1, 45.2) cooperate with corresponding mounting recesses (46.1, 46.2) in the compressor drum (20) and cover upstream and downstream bearing areas (26.1, 26.2) in the unit (24).

11. The method according to claim 10, wherein: The method further comprises the step of machining a channel area (40) for a gasket to have alternating protruding portions (48) and flat portions (49) to facilitate mounting of a protection element (45.1, 45.2) on the compressor drum (20).

12. The method according to claim 10 or 11, wherein: Each protection element (45.1, 45.2) is installed by applying a radial force to the protection element (45.1, 45.2) so that the connecting wall (53.1, 53.2) of the protection element (45.1, 45.2) is deformed to allow the protruding portion (57.1, 57.2) of each protection element (45.1, 45.2) to cooperate with the corresponding mounting groove (46.1, 46.2) before the connecting wall (53.1, 53.2) returns to its original flat shape, thereby covering the corresponding outer face (30.1, 30.2) of the compressor drum (20).

13. The method according to any one of claims 10 to 12, wherein: The method further comprises the step of machining the outer face (30.1, 30.2) of the compressor drum (20) upstream and downstream of the unit (24), respectively.

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