Holding system for removing a paddle wheel

TECHNICAL AREA

This disclosure 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 document FR 3 008 448, a turbine rotor comprising a movable impeller 1, that is to say configured to be driven in rotation about the axis of the rotor, shown in Figure 1, forming a ring, and which comprises a disc 2 around which are mounted circumferentially a set of blades 3. It is also known to axially maintain the blades 3 by means of a retaining ring 17. In operation , the retaining ring 17 is subject to wear more quickly than the disc 2. It must therefore be replaced more regularly. However, in order to reach the retaining ring 17, and to be able to replace it, it is necessary to remove the paddle wheels arranged downstream of the paddle wheel which includes the used retaining ring. Gold, to remove the vanes from the various moving impellers arranged downstream, the vanes must be removed one by one from the disks, then, once the retaining ring has been replaced, reassemble the vanes one by one on the impeller disks mobile. Such an operation is time consuming and represents a significant cost.

PRESENTATION

The present disclosure aims to resolve all or part of the drawbacks mentioned above.

[0004] To this end, the present disclosure relates to a holding system for removing a paddle wheel, the paddle wheel comprising:

- a disk,

a plurality of vanes configured to be mounted circumferentially around the disc, 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 into each of the inter-blade spaces in a holding position so as to maintain the relative position of the blades when the plurality of blades is removed from the disk.

Called axis of the paddle wheel, tax symmetry (or quasi-symmetry) thereof. This axis corresponds to the rate of rotation of the paddle wheel. The axial direction corresponds to the tax direction of the paddle wheel and a radial direction is a direction perpendicular to the axis of the paddle wheel and intersecting this axis. Likewise, 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 the center of which belongs to the axis of the paddle wheel. A circumferential direction is a direction along a circumference.

[0007] Unless otherwise specified, the adjectives inside / inside and outside / outside are used with reference to a radial direction so that the inside part of an element is, in a radial direction, closer to the axis of the wheel paddle as the outer part of the same element.

[0008] Thanks to these arrangements, it is possible to access the retaining ring by removing the disk from a given movable impeller, without having to dismantle the movable impellers arranged downstream. Thus, a saving of time is obtained to access a damaged retaining ring carried by this given movable paddle wheel. Indeed, the relative position of the blades being maintained, it is possible to remove and reassemble all the blades on the disk at once, without having to dismantle 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 located 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.

[0011] For example, the position for maintaining the inserts is preferably as close as possible to the disc, in order to maintain the blades as well as possible.

[0012] In some embodiments, the impeller further comprises a retaining ring configured to axially hold the vanes on the disc.

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

In some embodiments, the position for maintaining the inserts is located at an internal portion of the inter-blade space, defined between the blade root and the center of the inter-blade space according to a radial direction.

It is understood that at least 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 conforms to the shape of a portion of the blades of two adjacent vanes.

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

[0017] 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 aluminum.

[0019] For example, the inserts could comprise a portion comprising an aluminum-based alloy coated with a polymer.

[0020] 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.

[0022] For example, the at least one portion consists of an aluminum-based alloy, and / or of a polymer having a Shore A hardness of between 75 and 100.

It is understood that the material forming the blade is softer 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 material harder 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 blade in the radial direction.

The height of a blade of a blade is understood to mean the greatest distance between a platform of the blade root and a platform of the blade head.

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.

In some embodiments, 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 comprises 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 facilitate assembly. of the insert in an inter-blade space.

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

[0032] For example, the gripping portion can allow the inserts to be mounted 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.

[0033] 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. inserts, 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 maintain the position of the blades with respect to each other more effectively, and will facilitate the dismantling of the blade. disk.

For example, the positioning device allows slightly different inserts 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% from the determined height.

The positioning device allows the radial blocking of the inserts which guarantees the integrity of the assembly comprising the blades and the inserts, in particular when the disc is removed.

[0038] In certain embodiments, the positioning device comprises a positioning ring, the positioning ring comprising fixing elements to allow the fixing of the inserts on the positioning ring.

[0039] Thus, the inserts are maintained in their holding position, which makes it possible to maintain the relative position of the blades more effectively.

It is understood that the positioning device is annular.

[0041] In some embodiments, the fixing elements allow the fixing of the inserts on the positioning ring.

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

[0043] For example, the fastening elements comprise oblong slots each opening 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.

[0044] 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, by cooperating with the blind hole.

For example, the blind hole is bored and the fixing member is threaded.

For example, the fasteners are threaded and are configured to cooperate with the bored blind holes present in each of the inserts. In addition, the fasteners are configured to hold the inserts against the positioning ring, for example by means of a stop element, such as a screw head.

In some embodiments, the inserts each comprise a first member and a second member, the first and second members being configured to be disposed in an inter-blade space, the first member being disposed against a first vane, 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

organs so as to maintain the insert between the first and second vanes.

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

[0050] 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 tightening to each inter-blade space, as a function of the insertion of the tightening part.

For example, the holding system comprises a stop disc, allowing the positioning of the inserts.

In some embodiments, at least one of the first and second members comprises a guide surface, configured to guide the clamping piece during its insertion between the first and second members and to avoid radial displacement of the clamping piece .

In some embodiments, the clamping piece comprises a stopper configured to come into contact with the first and second members when the clamping piece is mounted between the first and second members.

[0054] In some embodiments, the clamping piece has a wedge, bevel, conical or rectangular shape.

The present disclosure further relates to a method of disassembling a paddle wheel comprising a disk and a plurality of vanes mounted circumferentially around the disk, the plurality of vanes defining a plurality of inter-vane spaces. , the inter-blade spaces each being defined circumferentially between two adjacent blades of the plurality of blades, the dismantling method comprising the following steps:

A. inserting a plurality of inserts of a retaining system into the inter-vane spaces in a holding position so that the relative position of the vanes is maintained;

B. remove the disc.

Thanks to these arrangements, it is possible to access the retaining ring by removing the disc from a movable impeller.

given, without having to dismantle the movable paddle wheels arranged downstream. Thus, a saving of time is obtained to access a damaged retaining ring carried by this given movable paddle wheel. Indeed, the relative position of the blades being maintained, it is possible to remove and reassemble all the blades on the disk at once, without having to dismantle 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.

In some embodiments, the method further comprises the following steps:

- replace a retaining ring configured to maintain the position of the blades in an axial direction,

- re-engage the blades on the disc,

- remove the paddlewheel retaining system.

In some embodiments, during step A:

- the inserts are inserted at the level of a radially outer portion of the inter-blade spaces, and

- The inserts are moved in a radial direction, radially inward, until the holding position is reached.

Thus, it is possible to adjust the position of the inserts as a function of the force that is to be applied to the blades and as a function of the tolerances / dimensional dispersions of the blades.

According to one variant, 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.

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 level of 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 disposed circumferentially facing the first member,

- The clamping piece is inserted between the first and second members so as to maintain the insert in the holding position.

Thus, the mounting of the inserts can be performed axially if the radial mounting is difficult to achieve in certain circumstances.

For example, to position and hold the inserts in the holding position, a positioning device can be placed at the level of the holding position of the inserts.

For example, the positioning device comprises a positioning ring, and the positioning ring is positioned so that the fixing elements, for example oblong slots, are at the level of the holding position of the inserts. Thus, when the inserts are mounted, and face the fixing elements, the inserts can be fixed to the positioning ring.

For example, the inserts are fixed on the positioning ring thanks to the fixing elements.

BRIEF DESCRIPTION OF THE DRAWINGS

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:

- Figure 1 shows a paddle wheel;

- Figure 2 shows a sectional view of the paddle wheel along the plane II-II of Figure 1;

- Figure 3 shows a schematic view of a portion of a paddle wheel in which inserts are inserted into the inter-blade spaces;

- Figure 4 shows an insert according to a first embodiment;

- Figure 5 shows an insert according to the first embodiment, mounted on the paddle wheel and fixed to a positioning device;

- Figure 6 shows an insert according to the first embodiment on which is mounted a gripping portion;

- Figure 7 shows a portion of the paddle wheel, on which is mounted a retaining system according to the first embodiment;

- Figure 8 shows a portion of the paddle wheel, on which is mounted an insert according to the second embodiment;

- Figure 9 shows a step of mounting an insert according to the first embodiment in an inter-blade space.

DETAILED DESCRIPTION

FIG. 1 represents a paddle wheel 1. For example, the paddle wheel 1 is installed at the level of the low pressure turbine of a turbomachine.

The impeller 1 comprises a disc 2 and a plurality of blades 3. The plurality of blades 3 is mounted on the disc 2 around its circumference.

Figure 2 is a section of the paddle wheel 1 along the plane II-II shown in Figure 1. The blade 3 shown in Figure 2 comprises a blade 5, a blade root 7 and a head of The blade 9. The blade root 7 comprises a radially internal platform 11. The blade head 9 comprises a radially external 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 from each other so as to define inter-vane spaces 15, visible in FIG. 1 for example. It will be 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 heads 9 than

proximity of the blade roots 7. Thus, the distance between two blade blades decreases between the blade heads 9 and the blade roots 7.

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

Figures 1 and 2 also show a retaining ring 17, configured to axially block the blades 3 on the disc 2.

Figure 3 shows a portion of a paddle wheel 1 and a holding system 19 for removing the paddle wheel 1. The holding system 19 comprises a plurality of inserts 21. The inserts 21 are here inserted into each of the inter-blade spaces 15 so as to maintain the relative position of the blades 3 and to allow the disassembly of the disc 1.

An insert according to the first embodiment 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. of 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 impeller.

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 is 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 impeller are held together via the inserts, which releases the stresses applied by the blade roots. 7 at the level of the cells of the disc in which the blade roots are mounted and thus allows easy assembly or disassembly of the disc.

For example, at least the portions of the first part 23 of the insert 21 in contact with the blades 5a, 5b of the vanes 3a, 3b, and preferably at least the first part 23 of the insert 21, comprise / comprises an 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 along a plane normal to the radial direction DR is greater than the dimension along this plane of the inter-blade space 15 near the feet of blade 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 a portion having substantially the same dimension as the dimension of the section. of the insert 21 in a plane normal to the radial direction DR.

Generally, the inserts 21 are arranged at 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 space. inter-blades 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 according to 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 dimensional tolerances or dispersions of the blades, the height in 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 for maintaining the inserts 21 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 vane 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 include a gripping portion 31 of the inserts 21. The gripping portion 31 can be mounted on the second part 25. The gripping portion 31 allows to form a handle, long enough to allow a user to grip it easily. Thus, the gripping portion 31 makes it possible to facilitate the handling 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 The user can use the same gripping portion 31 for mounting all of the inserts 21.

In addition, as shown in Figure 7, the holding system 19 may include a positioning device 33. The positioning device 33 comprises, in this embodiment, a positioning ring 35 configured to be positioned against the vanes 3, in a circumferential direction. 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 in 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 fastener 39 allows the insert 21 to be fixed on the positioning ring 35. For example, as shown, the fastener 39 is a screw, configured to fit 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 stop disk 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 disc. Once the plurality of inserts have been mounted, an external radial locking disc is positioned making it possible to maintain the position of the inserts 21.

The method for removing the paddle wheel 2 according to the first 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, we first insert the inserts 21 at an outer portion of the inter-blade space 15, as shown in Figure 9, then we move the inserts 21, for example through the portion of gripping 31, in the radial direction DR, along arrow F, that is to say inwards, until the holding position is reached. 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.

For example, 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 located at the position of holding 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 fasteners 39 which can be inserted into the blind holes 37 of the inserts 21.

Once all of the inter-vane spaces 15 of the impeller 1 is provided with an insert 21, the disc 2 can be removed. After removing the disc 2, it is possible, for example, to proceed replacing the retaining ring 17. Then, the disc 2 can be re-engaged with all of the blade roots 7 of the blades 3, since their relative position has been maintained by the inserts. Finally, once the vanes 3 are raised 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 various 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 disposed against the blade 5a of the first blade 3a and the second member 43 is disposed against the blade 5b of the second blade 3b, circumferentially adjacent 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 piece 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.

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

[0100] The guide surfaces are here formed by grooves 47, 49, formed in each of the first and second members 41, 43. The edges of the grooves 47, 49 allow the radial locking of the clamping part 45 and a guiding in axial translation of the clamping piece 45.

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

[0102] 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 FIG. 8, an internal radial stop disk 34 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 paddle wheel 1 by virtue of 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, we have the first member 41 of an insert 21 against the blade 5a of the first blade 3a, at the holding position. Then, the second member 43 of the insert 21 is placed against the blade 5b of the second vane 3b, circumferentially adjacent to the first vane 3a, also at the holding position, so that the second member 43 is arranged 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-vane spaces 15 of the impeller 1 is provided with an insert 21, in the same way as in the first embodiment, the disc 2 can be removed. removed the disc 2, one can, for example, proceed to the replacement of the retaining ring 17. Then, one can easily re-engage the disc 2 with the set of blade roots 7 of the blades 3, since their relative position has been held by the inserts. Finally, once the vanes 3 are raised on the disc 2, the retaining system 19 can be removed.

[0108] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the revendications. In particular, individual characteristics of the different illustrated / mentioned embodiments can be combined in additional embodiments. Therefore, the description and the drawings should be taken in an illustrative rather than a 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 device. a method.
CLAIMS

1. Retaining system (19) for removing a paddle wheel

(1), the paddle wheel (1) comprising:

- a disc (2),

- a plurality of vanes (3) configured to be mounted circumferentially around the disc (2), the plurality of vanes (3) defining a plurality of inter-vane spaces (15), the inter-vane spaces (15) each 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), each of the inserts (21) being configured to be inserted into each of the inter-vane spaces (15) in a holding position so as to maintain the relative position vanes (3) when the plurality of vanes (3) is removed from the disc (2).

2. 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 of between 75 and 100. .

3. 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 a blade of a blade in the radial direction (DR).

4. Holding system (19) according to one of the preceding claims, comprising a gripping portion (31) configured to be mounted on an insert (21) of the plurality of inserts, the gripping portion (31) being configured. to allow the insert (21) to be gripped and to facilitate the assembly of the insert (21) in an inter-blade space (15).

5. Holding system (19) according to one of the preceding claims, comprising a positioning device (33, 34) of the plurality of inserts, each insert (21) of the plurality of inserts being configured to be attached to the positioning device (33, 34) so ​​as to hold the inserts (21) in position.

6. A holding system according to claim 5, wherein the positioning device (33) comprises a positioning ring (35), the positioning ring (35) comprising fixing elements (37) to allow the fixing of the inserts. (21) on the positioning ring (35).

7. Holding system (19) according to one of claims 1 to 3, wherein the inserts (21) each comprise:

- 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 vane (3a), and the second member (43) being disposed against a second vane (3b) circumferentially adjacent to the first vane (3a); and

- a clamping piece (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 vanes (3a, 3b).

8. A method of dismantling a paddle wheel (1) comprising a disk (2) and a plurality of vanes (3) mounted circumferentially around the disk (2), the plurality of vanes (3) defining a plurality of vanes (3). 'inter-vane spaces (15), the inter-vane spaces (15) each being defined circumferentially between two adjacent vanes of the plurality of vanes (3), the dismantling method comprising the following steps:

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

B. remove the disc (2).

9. The method of 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 the holding position is reached.

10. The method of claim 8, wherein the inserts (21) each comprise a first member (41), a second member

(43) and a clamping piece (45), during step A:

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

- We have the second member (43) of the insert (21), 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);

- Inserting the clamping piece (45) between the first and second members (41, 43) so as to maintain the insert (21) in the holding position.