EP3807500B1 - Holding system for the dismantling of a blade wheel - Google Patents

Description

TECHNICAL AREA

This presentation relates to a holding system for removing a paddle wheel and a method for removing a paddle wheel.

TECHNOLOGICAL BACKGROUND

It is known from the prior art, in particular from the document FR 3 008 448 , a turbine rotor comprising a movable blade wheel 1, that is to say configured to be driven in rotation around the axis of the rotor, shown in figure 1 , forming a crown, and which comprises a disc 2 around which are circumferentially mounted a set of blades 3. It is also known to hold the blades 3 axially by means of a retaining ring 17. In operation, the retaining ring 17 is subject to faster wear than disk 2. It must therefore be replaced more regularly. However, to reach the retaining ring 17, and to be able to replace it, it is necessary to remove the impellers arranged downstream of the impeller which includes the used retaining ring. However, to remove the blades from the various impellers with movable blades arranged downstream, it is necessary to remove the blades from the discs one by one, then, once the retaining ring has been replaced, reassemble the blades on the discs of the wheels one by one. with moving paddles. Such an operation is time-consuming and represents a significant cost. EN 2604936 and US 5026032 disclose two workpiece clamping devices.

PRESENTATION

This presentation aims to resolve all or part of the drawbacks mentioned above.

• un disque,
• une pluralité d'aubes configurée pour être montée circonférentiellement autour du disque, la pluralité d'aubes définissant une pluralité d'espaces inter-aubes, les espaces inter-aubes étant chacun défini circonférentiellement entre deux aubes adjacentes de la pluralité d'aubes,

le système de maintien comprenant une pluralité d'inserts, chacun des inserts étant configuré pour être inséré aligné selon une direction circonférentielle dans chacun des espaces inter-aubes dans une position de maintien de façon à maintenir la position relative des aubes lorsque la pluralité d'aubes est démontée du disque.To this end, the present presentation relates to a holding system for dismantling a bladed wheel, the bladed wheel comprising:

• a disk,
• a plurality of vanes configured to be mounted circumferentially around the disk, the plurality of vanes defining a plurality of inter-vane spaces, the spaces inter-blades each being defined circumferentially between two adjacent blades of the plurality of blades,

the holding system comprising a plurality of inserts, each of the inserts being configured to be inserted aligned in a circumferential direction in each of the inter-blade spaces in a holding position so as to maintain the relative position of the blades when the plurality of vanes is removed from the disc.

The axis of the paddle wheel is called the axis of symmetry (or quasi-symmetry) thereof. This axis corresponds to the axis of rotation of the paddle wheel. The axial direction corresponds to the direction of the axis of the blade wheel and a radial direction is a direction perpendicular to the axis of the blade wheel and intersecting this axis. Similarly, an axial plane is a plane containing the axis of the impeller and a radial plane is a plane perpendicular to this axis.

A circumference is understood as a circle belonging to a radial plane and whose center belongs to the axis of the paddle wheel. A circumferential direction is a direction following a circumference.

Unless otherwise specified, the adjectives interior/internal and exterior/external are used with reference to a radial direction so that the interior part of an element is, in a radial direction, closer to the axis of the impeller than the outer part of the same element.

Thanks to these arrangements, it is possible to access the retaining ring by dismantling the disk of a given impeller, without having to disassemble the impellers with impellers arranged downstream. Thus, a saving of time is obtained in accessing a damaged retaining ring carried by this given movable impeller. Indeed, the relative position of the blades being maintained, it is possible to disassemble and reassemble all of the blades on the disk at one time, without having to disassemble or reassemble them one by one. Thus, the disassembly and reassembly of the paddle wheel is faster and more efficient. In addition, the inserts taking up the forces exerted on the disc, the disc is more easily removable.

The holding position is at a determined height of the inter-blade space in the radial direction.

When an insert is in the holding position, the center of the insert in the radial direction is at the determined height.

For example, the position for holding the inserts is preferably as close as possible to the disk, in order to hold the blades as well as possible.

In some embodiments, the blade wheel further includes a retainer ring configured to axially retain the blades to the disk.

In certain embodiments, each vane of the plurality of vanes comprises a root, a blade and a head, arranged in this order along a longitudinal direction of the vane. When the blade is mounted on the disc, the longitudinal direction of the blade corresponds to the radial direction.

In certain embodiments, the position for holding the inserts is at an internal portion of the inter-blade space, defined between the blade root and the center of the inter-blade space in a radial direction. .

It is understood that at least a part of each insert has a shape corresponding to the inter-blade space, defined between two adjacent blades. In addition, at least a portion of the inserts matches the shape of a portion of the blades of two adjacent blades.

It will be understood that, in the holding position, each insert is placed against, and preferably directly against, each of the adjacent blades defining the inter-blade space.

In certain embodiments, each of the inserts comprises at least one portion made of an aluminum-based alloy, and/or a polymer having a shore A hardness of between 75 and 100.

By “based on”, is meant an alloy comprising at least 50% by weight of aluminium.

For example, the inserts could comprise a portion comprising an aluminum-based alloy covered with a polymer.

For example, the polymer is a resin.

It is understood that the at least one portion comprising aluminum, or a polymer having a Shore A hardness of between 75 and 100 is a portion in contact with a blade.

For example, the at least one portion consists of an alloy based on aluminium, and/or a polymer having a shore A hardness of between 75 and 100.

It is understood that the material forming the blade is less soft than the aluminum-based alloy and/or the polymer having a Shore A hardness of between 75 and 100.

Thus, when the inserts are installed in their holding position, the risk of damaging the blades, which are formed from a harder material than the material of the portions of the inserts in contact with the blades, is more limited.

In some embodiments, the inserts have a thickness in a radial direction greater than or equal to 10% of the height of a blade of a vane in the radial direction.

By height of a blade of a blade is meant the greatest distance between a platform of the blade root and a platform of the blade tip.

Thus, sufficient contact surfaces with the blades are guaranteed and maintaining the position of the blades relative to each other is more effective.

For example, the thickness is about 10 mm, for a blade height of about 100 mm.

According to an example not forming part of the claimed invention, the insert comprises a first part and a second part. The first part is the part of the insert intended to be inserted into the inter-blade space. The second part is used, for example, for mounting the insert. The greatest length in an axial direction of the first part is between 10 mm and 20 mm, that is to say represents between 70% and 100% of the length of the blade of the blade in the axial direction.

In some embodiments, the holding system includes a gripping portion configured to be mounted on an insert of the plurality of inserts, the gripping portion being configured to allow the gripping of the insert and to facilitate the mounting of the insert in an inter-blade space.

Thus, the handling of the inserts during their insertion into the inter-blade spaces is facilitated.

For example, the gripping portion can make it possible to mount the inserts directly at their holding position, by a movement which follows the shape of the insert. Indeed, the gripping portion can form a lever arm which thus makes it possible to be able to exert sufficient force on the insert to insert it directly into the holding position.

In certain embodiments, the holding system comprises a device for positioning the plurality of inserts, each insert of the plurality of inserts being configured to be attached to the positioning device so as to hold the inserts in position, c 'that is to say so that the inserts are arranged in the holding position.

Thus, the inserts are substantially aligned in a circumferential direction, which makes it possible to balance the forces exerted on the blades, and thus to more effectively maintain the position of the blades with respect to each other, and will facilitate the dismantling of the disc.

For example, the positioning device allows slightly different insert holding positions in the radial direction, so as to compensate for the dimensional tolerances/dispersions of the blades.

By "substantially" or "slightly" is meant that the actual height in the radial direction of the inserts in their holding position differs by at most 5% relative to the determined height.

The positioning device allows radial blocking of the inserts which makes it possible to guarantee the integrity of the assembly comprising the blades and the inserts, in particular when the disc is disassembled.

In some embodiments, the positioning device includes a positioning ring, the positioning ring including fasteners to allow attachment of the inserts to the positioning ring.

Thus, the inserts are held in their holding position, which makes it possible to more effectively maintain the relative position of the blades.

It is understood that the positioning device is annular.

In some embodiments, the fasteners allow attachment of the inserts to the positioning ring.

In certain embodiments, the fixing elements of the positioning device are intended to be arranged opposite the inserts when the inserts are in the holding position, to allow the fixing of the inserts on the positioning device.

For example, the fixing elements comprise oblong openings each emerging facing an inter-blade space. For example, the oblong slots extend in the radial direction so as to allow a slightly different positioning of the inserts relative to each other in the radial direction.

For example, the inserts each comprise a blind hole extending in the axial direction. The blind hole is intended to come opposite the oblong slot when the insert is in the holding position.

For example, a fixing member makes it possible to fix the insert on the positioning ring, cooperating with the blind hole.

For example, the blind hole is reamed and the fastener is threaded.

For example, the fasteners are threaded and are configured to cooperate with the reamed blind holes present in each of the inserts. Furthermore, the fixing members are configured to hold the inserts against the positioning ring, for example thanks to a stop element, such as a screw head.

In certain embodiments, the inserts each comprise a first member and a second member, the first and second members being configured to be placed in an inter-blade space, the first member being placed against a first blade, and the second member being disposed against a second vane circumferentially adjacent to the first vane; and a clamp, configured to be inserted between the first and second bodies so as to maintain the insert between the first and second blades.

For example, the clamping piece is configured to be inserted between the first and second members in the axial direction.

Thus, the mounting of the inserts can be carried out axially in particular when the radial mounting is difficult to achieve in certain circumstances. This embodiment of the inserts also makes it possible to adapt the clamping to each inter-blade space, depending on the insertion of the clamping part.

For example, the holding system includes a stop disk, allowing the positioning of the inserts.

According to an example not forming part of the claimed invention, at least one of the first and second members comprises a guide surface, configured to guide the clamping part during its insertion between the first and second members and to avoid the radial displacement of the clamping piece.

According to an example not forming part of the claimed invention, the clamping part comprises an abutment configured to come into contact with the first and second members when the clamping part is mounted between the first and second members.

According to an example not forming part of the claimed invention, the clamping piece has a wedge, bevel, conical or rectangular shape.

1. A. insérer une pluralité d'inserts d'un système de maintien alignés selon une direction circonférentielle dans les espaces inter-aubes dans une position de maintien de sorte que la position relative des aubes soit maintenue ;
2. B. retirer le disque.

This presentation also relates to a method for disassembling a blade wheel comprising a disc and a plurality of blades mounted circumferentially around the disc, the plurality of blades defining a plurality of inter-blade spaces, the spaces inter-blades each being defined circumferentially between two adjacent blades of the plurality of blades, the dismantling method comprising the following steps:

1. A. inserting a plurality of inserts of a retaining system aligned in a circumferential direction into the inter-blade spaces in a retaining position so that the relative position of the blades is maintained;
2. B. remove the disc.

Thanks to these provisions, it is possible to access the retaining ring by dismantling the disk of a moving blade wheel given, without having to disassemble the impellers arranged downstream. Thus, a saving of time is obtained in accessing a damaged retaining ring carried by this given movable impeller. Indeed, the relative position of the blades being maintained, it is possible to disassemble and reassemble all of the blades on the disk at one time, without having to disassemble or reassemble them one by one. Thus, the disassembly and reassembly of the paddle wheel is faster and more efficient. In addition, the inserts taking up the forces exerted on the disc, the disc is more easily removable.

• remplacer un anneau de retenue configuré pour maintenir la position des aubes selon une direction axiale,
• réengager les aubes sur le disque,
• retirer le système de maintien de la roue à aubes.

According to an example not forming part of the claimed invention, the method further comprises the following steps:

• replacing a retaining ring configured to maintain the position of the blades in an axial direction,
• re-engage the blades on the disc,
• remove the impeller retainer.

• on insère les inserts au niveau d'une portion radialement externe des espaces inter-aubes, et
• on déplace les inserts selon une direction radiale, radialement vers l'intérieur, jusqu'à atteindre la position de maintien.

In some embodiments, during step A:

• the inserts are inserted at a radially outer portion of the inter-blade spaces, and
• the inserts are moved in a radial direction, radially inwards, until the holding position is reached.

Thus, it is possible to adjust the position of the inserts according to the force which it is desired to apply to the blades and according to the dimensional tolerances/dispersions of the blades.

According to a variant not forming part of the claimed invention, the inserts are inserted directly at their holding position, thanks to a gripping portion, by a movement which follows the shape of the insert. Indeed, the gripping portion can form a lever arm which thus makes it possible to be able to exert sufficient force on the insert to insert it directly into the holding position.

• on dispose le premier organe d'un insert, dans un espace inter-aubes, contre une première aube au niveau de la position de maintien,
• on dispose le deuxième organe de l'insert, dans l'espace inter-aubes, contre une deuxième aube, adjacente à la première aube, de façon à ce que le deuxième organe soit disposé circonférentiellement en regard du premier organe,
• on insère la pièce de serrage entre les premier et deuxième organes de façon à maintenir l'insert dans la position de maintien.

In certain embodiments, the inserts each comprise a first member, a second member and a clamping piece, during step A:

• the first member of an insert is placed, in an inter-blade space, against a first blade at the holding position,
• the second member of the insert is placed, in the inter-blade space, against a second blade, adjacent to the first blade, so that the second member is arranged circumferentially opposite the first member,
• the clamping piece is inserted between the first and second members so as to hold the insert in the holding position.

Thus, the mounting of the inserts can be carried out axially if the radial mounting is difficult to carry out in certain circumstances.

For example, to position and hold the inserts in the holding position, it is possible to arrange a positioning device at the level of the holding position of the inserts.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 représente une roue à aubes ;
• la figure 2 représente une vue en coupe de la roue à aubes selon le plan II-II de la figure 1 ;
• la figure 3 représente une vue schématique portion d'une roue à aubes dans laquelle des inserts sont insérés dans les espaces inter-aubes ;
• la figure 4 représente un insert selon un exemple ne faisant pas partie de l'invention revendiquée;
• la figure 5 représente un insert monté sur la roue à aubes et fixé à un dispositif de positionnement ;
• la figure 6 représente un insert selon une mode de réalisation sur lequel est montée une portion de préhension ;
• la figure 7 représente une portion de la roue à aubes, sur laquelle est monté un système de maintien selon une mode de réalisation ;
• la figure 8 représente une portion de la roue à aubes, sur laquelle est montée un insert selon le deuxième mode de réalisation ;
• la figure 9 représente une étape du montage d'un insert selon une mode de réalisation dans un espace inter-aubes.

The invention and its advantages will be better understood on reading the detailed description given below of various embodiments of the invention given by way of non-limiting examples. This description refers to the pages of appended figures, on which:

• the figure 1 represents a waterwheel;
• the picture 2 represents a sectional view of the paddle wheel according to the plane II-II of the figure 1 ;
• the picture 3 shows a schematic view portion of a paddle wheel in which inserts are inserted into the inter-blade spaces;
• the figure 4 represents an insert according to an example not forming part of the claimed invention;
• the figure 5 shows an insert mounted on the impeller and attached to a positioning device;
• the figure 6 represents an insert according to one embodiment on which a gripping portion is mounted;
• the figure 7 represents a portion of the paddle wheel, on which is mounted a holding system according to one embodiment;
• the figure 8 represents a portion of the paddle wheel, on which is mounted an insert according to the second embodiment;
• the figure 9 represents a step in the assembly of an insert according to one embodiment in an inter-blade space.

DETAILED DESCRIPTION

The figure 1 represents a blade wheel 1. For example, the blade wheel 1 is installed at the level of the low pressure turbine of a turbomachine.

The paddle wheel 1 comprises a disc 2 and a plurality of vanes 3. The plurality of vanes 3 are mounted on the disc 2 around its circumference.

The picture 2 is a section of the bladed wheel 1 according to the plane II-II shown in figure 1 . Dawn 3 represented on the figure 2 comprises a blade 5, a blade root 7 and a blade tip 9. The blade root 7 comprises a radially inner platform 11. The blade tip 9 comprises a radially outer platform 13. The blade 5 extends radially between the platforms 11, 13. All the blades 3 of the plurality of blades are similar to the blade shown in figure 1 . The blades 5 of the blades 3 each have a concave face and a convex face.

When they are mounted on the disc 2, the vanes 3 extend in a radial direction DR and are spaced apart from each other so as to define inter-vane spaces 15, visible on the figure 1 for example. It is understood that an inter-blade space 15 is defined between two adjacent blades 3. The distance between two blades 5 of adjacent blades 3 is greater near the blade tips 9 than at proximity of the blade roots 7. Thus, the distance between two blade blades decreases between the blade tips 9 and the blade roots 7.

The vanes 3 are mounted on the disc 2 in a nominal operating position.

The figure 1 and 2 also represent a retaining ring 17, configured to axially block the blades 3 on the disc 2.

The picture 3 represents a portion of a bladed wheel 1 and a holding system 19 for removing the bladed wheel 1. The holding system 19 comprises a plurality of inserts 21. The inserts 21 are here inserted aligned in a circumferential direction in each of the inter-blade spaces 15 so as to maintain the relative position of the blades 3 and to allow the dismantling of the disc 1.

An insert according to an example not forming part of the claimed invention is shown in figures 4 and 5 .

The insert 21 comprises a first part 23 and a second part 25. The first part 23 is configured to maintain the relative position of the blades 3. The first part 23 comprises a first contact surface 27, configured to come into contact with a blade 5a of a first blade 3a and match the shape of the convex face of the blade 5a. Here, the first contact surface 27 therefore has a concave shape. In other words, the first contact surface 27 and the convex face of the blade 5a have complementary shapes.

The first part 23 further comprises a second contact surface 29, configured to come into contact with a blade 5b of a second blade 3b and match the shape of the concave face of the blade 5b. Here, the second contact surface 29 therefore has a convex shape. In other words, the second contact surface 29 and the concave face of the blade 5b have complementary shapes. The first and second vanes 3a, 3b are adjacent in the circumferential direction of the vane wheel.

The convex face of the blade 5a and the concave face of the blade 5b face each other in the circumferential direction. The surfaces of the blades 5a, 5b of the first and second blades 3a, 3b define the inter-blade space 15.

It will be understood that the first part 23 of the insert 21 has a shape corresponding to a portion of the inter-blade space 15, when the blades 3 are in the nominal position. Thus, when the inserts 21 are mounted in the inter-blade spaces 15 at a holding position, the blades of the blade wheel are held together via the inserts, which releases the stresses applied by the blade roots. 7 at the level of the cells of the disk in which the blade roots are mounted and thus allows easy assembly or disassembly of the disk.

For example, at least the portions of the first part 23 of the insert 21 in contact with the blades 5a, 5b of the blades 3a, 3b, and preferably at least the first part 23 of the insert 21, comprise/comprises a aluminum-based alloy, and/or a polymer having a Shore A hardness of between 75 and 100. For example, the polymer is a resin.

The dimension of the section of the first part 23 of the insert 21 according to a plane normal to the radial direction DR is greater than the dimension according to this plane of the inter-blade space 15 near the blade roots 7. Thus, the insert 21, in the position for maintaining the relative position of the blades 3, is positioned in the inter-blade space 15 at the level of a portion having substantially the same dimension as the dimension of the section of the insert 21 along a plane normal to the radial direction DR.

Generally, the inserts 21 are arranged at the level of a first end portion of the inter-blade spaces 15, defined, for each inter-blade space, between the blade root 7 and the center of the inter-blade space. 15 in the radial direction DR.

The inserts 21, and more particularly their first part 23, have a thickness e in the radial direction DR greater than or equal to 10% of the height h of the blade in the radial direction DR.

The holding position of each insert is at a determined height of the inter-blade space 15, or of the adjacent blades 5. When the insert 21 is in the holding position, the center of the insert in the radial direction, that is to say, a height of the insert corresponding to half of its thickness e, is at the level of the determined height. Sometimes, because of the dimensional tolerances or dispersions of the blades, the height according to the radial direction, corresponding to the holding position, is significantly different at the height determined for certain inserts. However, the difference between the actual height of the position in which the inserts 21 are held and the determined height is less than or equal to 5% of the total height of the blade 5, or of the inter-blade space 15.

For example, the thickness e is approximately 10 mm, for a blade height of approximately 100 mm. For example, the greatest length in an axial direction DA of the first part 23 is 15 mm, that is to say between 70 and 100% of the length in the axial direction DA of the blade 5 of the blade 3.

The second part 25 of the insert 21 is connected to the first part of the insert 23. For example the first and second parts 23, 25 are formed together.

The second part 25 extends, here, in the extension of the first part 23 in the axial direction DA. The second part 25 provides a gripping means making it possible to engage or disengage the insert 21 from the inter-blade space 15. The second part 25 can also serve as a support for mounting the insert 21 on other elements.

For example, as shown in figure 6 , the holding system 19 may further comprise a gripping portion 31 of the inserts 21. The gripping portion 31 can be mounted on the second part 25. The gripping portion 31 makes it possible to form a handle, long enough to allow a user to grasp it easily. Thus, the gripping portion 31 facilitates the manipulation of the inserts 21 and their insertion into the inter-blade spaces 15. For example, the gripping portion 31 is removably mounted on the second part 25. In this way, the user can use the same gripping portion 31 for mounting all the inserts 21.

Furthermore, as shown in the figure 7 , the holding system 19 may comprise a positioning device 33. The positioning device 33 may comprise a positioning ring 35 configured to be positioned against the blades 3, in a circumferential direction. The positioning ring 35 includes oblong slots 37 opening towards the inter-blade space 15. The oblong slots 37 extend in a radial direction DR so as to allow a slightly different positioning of the inserts 21 with respect to each other in the radial direction DR, so as to take into account dimensional tolerances/dispersions.

For example, the second part 25 comprises a bored blind hole 38 extending along the axial direction DA. The blind hole 38 is intended to come opposite the oblong slot 37, when the insert 21 is in the holding position. A fixing member 39 makes it possible to fix the insert 21 on the positioning ring 35. For example, as shown, the fixing member 39 is a screw, configured to be inserted into the blind hole 38 bored. However, the insert 21 could be fixed on the positioning ring 35 by any other means. In this way, the inserts 21 are substantially aligned along the circumferential direction.

In order to position the inserts 21 at the same radial height in the inter-blade spaces according to another embodiment (not shown), an internal radial abutment disc could be provided at a predetermined height, corresponding to the holding position of the inserts 21. The second part 25 of the inserts could then come into abutment against the internal disk. Once the plurality of inserts has been mounted, an external radial locking disc is positioned to maintain the position of the inserts 21.

The method for dismantling the bladed wheel 2 according to the first embodiment is described below.

Initially, the inserts 21 are inserted, one by one, aligned in a circumferential direction in each of the inter-blade spaces 15, in their holding position.

For this, the inserts 21 are first inserted at an outer portion of the inter-blade space 15, as shown in figure 9 , then the inserts 21 are moved, for example thanks to the gripping portion 31, in the radial direction DR, according to the arrow F, that is to say inwards, until reaching the holding position. By outer portion of the inter-blade space 15 is meant a portion defined between the center of the blade 5 in the radial direction DR and the outer end of the blade 5.

According to a variant, the inserts 21 are placed directly at their holding position by a movement which follows the shape of the first and second contact surfaces 27, 29, thanks to the gripping portion 31 which forms, in this variant, a lever arm and which thus makes it possible to exert sufficient force on the insert 21 to insert it directly into the holding position.

According to an example not forming part of the claimed invention, to position and hold the inserts 21 in the holding position, the positioning ring 35 can be arranged so that the oblong slots 37 are at the level of the holding position of the inserts 21. Thus, when the inserts are mounted, and face the oblong slots, they are fixed to the positioning ring 35, here thanks to the fixing members 39 which can be inserted into the blind holes 37 of the inserts 21.

Once all of the inter-blade spaces 15 of the bladed wheel 1 are provided with an insert 21, the disc 2 can be removed. After removing the disc 2, it is possible, for example, to replace the the retaining ring 17. Then, the disc 2 can be reengaged with all of the blade roots 7 of the blades 3, since their relative position has been maintained by the inserts. Finally, once the blades 3 have been reassembled on the disc 2, the retaining system 19 can be removed.

A second embodiment of the holding system is shown in figure 8 . In what follows, the elements common to the different embodiments are identified by the same reference numerals. The second embodiment differs from the first embodiment in that the inserts 21 each comprise a first member 41 and a second member 43. The first and second members 41, 43 are configured to be arranged, in an inter-blade space 15 The first member 41 is placed against the blade 5a of the first blade 3a and the second member 43 is placed against the blade 5b of the second blade 3b, adjacent circumferentially to the first blade 3a. The first and second members 41, 43 face each other in the circumferential direction of the paddle wheel.

The inserts 21 further each comprise a clamping part 45, configured to be inserted, in the axial direction DA, between the first and second members 41, 43, so as to hold the first and second members 41, 43 against the blades 5a , 5b. In the embodiment shown, the clamping piece 45 has a wedge or bevel shape.

In order to guide the clamping piece 45 between the first and second members 41, 43 during its insertion in the axial direction and therefore prevent its radial displacement, at least one of the first and second members 41, 43 comprises a guide surface. In the example shown, each of the first and second members 41, 43 comprises a guide surface.

The guide surfaces are here formed by grooves 47, 49, made in each of the first and second members 41, 43. The edges of the grooves 47, 49 allow the radial blocking of the clamping part 45 and a guiding in axial translation of clamping piece 45.

In one embodiment, not shown, the clamping part 41 comprises an axial stop configured to come into contact with the first and second members 41, 43 when the clamping part 45 is mounted between the first and second members 41, 43.

For example, in order to position the inserts 21 at the same radial height in the inter-blade spaces according to the embodiment shown in figure 8 , an internal disc 34 of radial abutment could be provided at a predetermined height, corresponding to the holding position of the inserts 21. The first and second members could be positioned in abutment against the internal disc 34, before the insertion of the clamping piece.

The method for removing the bladed wheel 1 using a holding system according to the second embodiment is described below.

First, the inserts 21 are inserted, one by one, into each of the inter-blade spaces 15, in their holding position.

For this, the first member 41 of an insert 21 is placed against the blade 5a of the first blade 3a, at the level of the holding position. Then, the second member 43 of the insert 21 is placed against the blade 5b of the second blade 3b, circumferentially adjacent to the first blade 3a, also at the level of the holding position, so that the second member 43 is placed in face of first member 41 in the circumferential direction of the paddle wheel. Then, the clamping piece 45 is inserted between the first and second members 41, 43.

Inserts 21 are thus inserted into each of the inter-blade spaces 15.

Once all of the inter-blade spaces 15 of the bladed wheel 1 are provided with an insert 21, in the same way as in the first embodiment, the disc 2 can be removed. After removing the disc 2, it is possible, for example, to replace the retaining ring 17. Then, the disk 2 can be easily reengaged with all of the blade roots 7 of the blades 3, since their relative position has been maintained by inserts. Finally, once the blades 3 have been reassembled on the disc 2, the retaining system 19 can be removed.

Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. Accordingly, the description and the drawings should be considered in an illustrative rather than restrictive sense.

It is also obvious that all the characteristics described with reference to a method can be transposed, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device can be transposed, alone or in combination, to a method.

Claims (10)

1. A holding system (19) for the dismantling of a blade wheel (1), the blade wheel (1) comprising:

   - a disc (2),

   - a plurality of blades (3) configured to be mounted circumferentially around the disc (2), the plurality of blades (3) defining a plurality of inter-blade spaces (15), each of the inter-blade spaces (15) being defined circumferentially between two adjacent blades (3a, 3b) of the plurality of blades (3),

   the holding system (19) comprising a plurality of inserts (21), characterized in that each of the inserts (21) are configured to be inserted into each of the inter-blade spaces (15) in a holding position so as to hold the relative position of the blades (3) when the plurality of blades (3) is dismantled from the disc (2).
2. The holding system (19) according to claim 1, wherein each of the inserts (21) comprises at least one portion made of an aluminum-based alloy, and/or a polymer having a Shore A hardness comprised between 75 and 100.
3. The holding system (19) according to one of claims 1 or 2, wherein the inserts have a thickness (e) in a radial direction (DR) greater than or equal to 10% of the height (h) of an airfoil of a blade in the radial direction (DR).
4. The holding system (19) according to one of the preceding claims, comprising a grip portion (31) configured to be mounted on an insert (21) of the plurality of inserts, the grip portion (31) being configured to allow the gripping of the insert (21) and facilitate the mounting of the insert (21) in an inter-blade space (15).
5. The holding system (19) according to one of the preceding claims, comprising a device (33, 34) for positioning the plurality of inserts, each insert (21) of the plurality of inserts being configured to be applied to the positioning device (33, 34) so as to hold the inserts (21) in position.
6. The holding system according to claim 5, wherein the positioning device (33) comprises a positioning ring (35), the positioning ring (35) comprising fastening elements (37) to allow the fastening of the inserts (21) on the positioning ring (35).
7. The holding system (19) according to one of claims 1 to 3, wherein each of the inserts (21) comprises:

   - a first member (41) and a second member (43), the first and second members (41, 43) being configured to be disposed in an inter-blade space (15), the first member (41) being disposed against a first blade (3a), and the second member (43) being disposed against a second blade (3b) circumferentially adjacent to the first blade (3a); and

   - a clamping part (45), configured to be inserted between the first and second members (41, 43) so as to hold the insert (21) between the first and second blades (3a, 3b).
8. A method for dismantling a blade wheel (1) comprising a disc (2) and a plurality of blades (3) mounted circumferentially around the disc (2), the plurality of blades (3) defining a plurality of inter-blade spaces (15), each of the inter-blade spaces (15) being defined circumferentially between two adjacent blades of the plurality of blades (3), characterized in that the dismantling method comprises the following steps:

   A. inserting a plurality of inserts (21) of a holding system (19) into the inter-blade spaces (15) in a holding position so that the relative position of the blades (3) is held;

   B. withdrawing the disc (2).
9. The method according to claim 8, wherein, during step A:

   - the inserts are inserted at a radially outer portion of the inter-blade spaces (15);

   - the inserts (21) are moved in a radial direction (DR), radially inward, until they reach the holding position.
10. The method according to claim 8, wherein each of the inserts (21) comprises a first member (41), a second member (43) and a clamping part (45), during step A:

    - the first member (41) of an insert (21) is disposed, in an inter-blade space (15), against a first blade (3a) at the holding position;

    - the second member (43) of the insert (21) is disposed, in the inter-blade space (15), against a second blade (3b), adjacent to the first blade (3a), so that the second member (43) is disposed circumferentially facing the first member (41);

    - the clamping part (45) is inserted between the first and second members (41, 43) so as to hold the insert (21) in the holding position.

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