WO2021008815A1

WO2021008815A1 - Blade ring for an axial turbomachine

Info

Publication number: WO2021008815A1
Application number: PCT/EP2020/067265
Authority: WO
Inventors: Milan Schmahl
Original assignee: Siemens Energy Global GmbH & Co. KG
Priority date: 2019-07-18
Filing date: 2020-06-22
Publication date: 2021-01-21
Also published as: DE102019210647A1

Abstract

The invention relates to a blade ring (2) for an axial turbomachine, comprising a blade support (6) with a number of holding grooves (8) for rotor blades (10), said grooves running in the axial direction (A), and a corresponding number of blades (10) which are inserted into the holding grooves (8). A spring element (14) is arranged between at least one of the rotor blades (10) and a holding groove base (12) of the corresponding holding groove (8). A particularly simple assembly or disassembly of the rotor blade (10) into or out of the holding groove (8) is facilitated by a corresponding design of the spring element (14). The spring element (14) is designed in multiple parts and comprises at least one fixing plate (16) and at least one spring plate (18), wherein the spring plate (18) is designed to be thinner than the fixing plate (16), and a spring force which acts radially outwards on the rotor blade (10) is generated by the shape and/or the arrangement of the spring plate (18).

Description

description

Blade ring for an axial turbo machine

The invention relates to a blade ring for an axial turbo machine, comprising a blade carrier with a number of axially extending retaining grooves for rotating blades and a corresponding number of rotating blades which are inserted in the retaining grooves, with at least one of the rotating blades and a retaining groove base between ent speaking retaining groove a spring element is arranged. The invention also relates to a method for assembling a rotor blade of such a blade ring. The invention finally be a method for dismantling a rotor blade of such a blade ring.

In gas turbines, the blades are usually grooves in the rotor, also known as holding grooves, attached. Some Hal tenuten are axially oriented in the direction of flow. The blade is pushed in axially and must then be fixed in the installation position. It is advantageous if the blades are pushed radially outwards in addition to the axial fixation. This minimizes wear on the retaining groove connection and enables optimum finishing of the blade length in the rotor. At the same time, the removal of the blades should be as uncomplicated as possible, since the blades must be removed at irregular intervals in order to renew the anti-corrosion layer.

From EP 1 703 078 A1 it is known, for example, to secure the blades seated in axial retaining grooves by using a locking plate against displacement along the retaining grooves. A locking plate is placed between the blade base and the retaining groove on the base of the retaining groove. A bead on the locking plate engages the locking plate in an opening provided on the foot side. After inserting the blade with the locking plate and bending over the surrounding ends on the entry and exit sides the foot a positive locking is achieved. In order to be able to ensure a sufficiently pre-tensioned seat of the rotor blade in the holding groove during operation, the assembly of the rotor blade must also take place under a pre-tension. Assembly under preload leads to unfavorable wear and seizure on the wing, which increases the risk of cracking. Especially in the front stages of a compressor that flows axially through, that is, with large blades, where particularly large preload forces are required, the assembly or disassembly in the case of servicing the blade proves to be difficult.

The invention is therefore based on the object of enabling a particularly simple assembly or disassembly of the rotor blade of a blade ring in or out of the retaining groove by a corresponding design of the spring element.

A blade ring of the generic type is initially intended for use in an axial turbo machine. Since the blade ring has a blade carrier as a section of a rotor. A number of axially extending retaining grooves distributed around the circumference are present in the display carrier. A rotor blade with a blade root is fastened in each of these retaining grooves. For this purpose, the blades are pushed in the axial direction into the respective retaining groove. The retaining groove has a retaining groove base on the side facing the rotor axis, i.e. radially inward. Opposite, on the underside of the rotor blade, there is also a contact surface on the side facing the rotor axis.

At least one fixing plate is also generically arranged between the contact surface of the rotor blade and the retaining groove base in the blade carrier. This is used to axially secure the blades on the display carrier. To this end, the fixing plate stretches along the retaining groove, in particular over the entire length of the base of the retaining groove and the surface of the contact area. The fixing plate protrudes on both opposite sides lying ends an end face. This can be an end face on the rotor blade and / or an end face on the blade carrier. For this purpose, the fixing plate also has a fixing tab extending in the radial direction at least at one end.

According to the invention, in addition to the axial fixation, the ra-Diale bias of the blade is achieved by additionally using at least one spring plate. This is arranged for this purpose between the contact surface and the base of the retaining groove adjacent to the fixing plate. By elastic deformation of the fixing plate in the installed state (due to the shape and / or the arrangement of the spring plate), a spring force acting radially outward on the blade is generated.

The invention is based on the idea of separating the fixing function and the pressing or spring function of the otherwise inserted spring element from one another by providing at least two separate components. The two components thus differ from one another in terms of their shape, size and / or material, as a result of which the fixing function and the pressing function are decoupled from one another.

The fixing plate is designed here in the simplest form in the manner of a plate. It is advantageous if the thickness of the fixing plate is less than 0.2 times the width (measured in the direction tangential to the rotor axis) of the fixing plate, i.e. the fixing plate has a flat shape. It is not necessary for the fixing plate to have a constant thickness, although this is advantageous for production.

It is also advantageous if the fixing plate is made of a plastically deformable material in order to enable at least one tab to be bent at least partially. It has proven to be advantageous if only a slight elastic deformation occurs during bending, since parts - at least a tab - the fixing plate should be bent over and should remain in the bent state.

It must be ensured by means of sufficient strength, taking into account the material strength, that the fixing function is enabled, so that the rotor blade is reliably held in position in the axial direction. For this purpose, the thickness of the fixing plate is advantageously chosen between 1 mm and 4 mm. A thickness of the fixing plate between 0.4 mm and 0.5 mm has proven to be particularly advantageous.

The spring plate as the second component for securing the rotor blade is advantageously also designed in the manner of a sheet metal. Due to the shape and / or the arrangement of the at least one spring plate, a spring force acting radially outward is generated on the rotor blade. Under "shape and / or the arrangement" the geometric properties and / or the arrangement of the respective spring plate to the fixing plate, to the base of the retaining groove and / or to the rotor blade are understood.

It is not necessary that the spring plate likewise extend over the entire length of the retaining groove. For the advantageous generation and application of the radial forces by means of the spring plate, however, it is advantageous if this extends over at least 0.8 times the length of the fixed plate. It is particularly advantageous if the spring plate uses the full length in the axial direction and thus extends on both sides at least to the end of the retaining groove.

To enable elastic deformation of the spring plate, it is advantageously made significantly thinner than the fixing plate. Thin metal sheets have the advantage that they provide a relatively high elastic spring deflection, while the spring force is relatively low. It is advantageous if the thickness of the spring plate is less than 0.1 times the width of the spring plate. It is still advantageous adhesive if the thickness is between 0.2 mm and 0.7 mm. A thickness between 0.4 mm and 0.5 mm has proven to be particularly advantageous.

So that the spring steel sheet is designed with particularly good elastic properties, the spring steel sheet is preferably made of spring steel. In general, and especially when using a spring steel, it is particularly advantageous if the spring steel sheet is Herge from a flat flat material. It is also advantageous if the spring plate in the non-installed state also has the flat shape and therefore does not have to be bent in the manufacturing process.

The spring force can be increased by appropriately stacking several spring plates, while the spring travel remains advantageously high. In this respect, it is advantageous to use at least two or more spring steel sheets, which are net angeord radially one above the other. In this way, each of the spring plates can be chosen to be relatively thin, and the resilient properties can be adjusted by the number of spring plates. It can be provided that these are arranged on both sides of the fixing plate. In this case, however, it is particularly advantageous to arrange the spring steel sheets in layers between the fixing sheet and the base of the retaining groove.

According to a preferred embodiment, a spring force that is sufficient for the radial pressure on the rotor blade can be generated in that the at least one spring plate is designed as a flat plate and, when arranged between the fixing plate and the base of the retaining groove, a concave surface, or when arranged between the fixing plate and the contact surface this has a convex shape.

The main advantage here is that the spring steel sheet or spring steel sheets can be cut out or punched from flat metal sheets and are thus ready for installation without any further deformation being necessary. The cutting out can be done, for example, by water jet cutting, since the cut edges are not thermally stressed or metallurgically changed.

It is particularly advantageous if the contact surface is convex and the base of the retaining groove is concave (i.e. curved in the same direction) and the fixing plate is also curved, i.e. it is in the form of a curved plate. It when the fixing plate is formed complementary to the contact surface and the holding groove is particularly advantageous. Correspondingly, the fixing plate has a radius of curvature which corresponds to a radius of curvature of the retaining groove base on the side facing the rotor axis and a radius of curvature of the contact surface on the side facing radially outward. In this way, the at least one flat spring plate is advantageously and easily deformed radially and thus the elastic, radially acting spring force is generated.

Alternatively, however, it is also possible that the base of the retaining groove and / or the contact surface and / or the fixing plate are curvature-free, i.e. designed to be flat. In contrast, the at least one spring plate has a curved shape, whereby a radial spring force is also generated due to the interaction of the geometries of the retaining groove base or contact surface and the spring plate. For this purpose, the spring plate can advantageously have a corrugated shape. The spring force is generated by the waviness of the spring plate, the Fe derweg being determined in a simple manner by the height of the waves.

According to a preferred embodiment, a region of the spring steel sheet on an assembly side protrudes axially over an end face of the blade carrier and / or the rotor blade, ie from the retaining groove. This overhang simplifies the assembly and in particular the disassembly of the spring steel sheet from the blade rim. Usually, assembly and disassembly work on a blade installed in a blade ring is only carried out on one side, so the blade ring has a more accessible assembly side and a rear side. So that the Fe derblech can be easily pulled out of the Hal tenut during dismantling, it is dimensioned such that the protrusion is easily accessible on the assembly side.

In a particularly preferred embodiment, the spring plate has at least one disassembly hole in the protrusion. The disassembly hole is preferably easily accessible from the assembly side. The disassembly hole is used to disassemble the spring steel sheet from the retaining groove. For this purpose, a tool is preferably used which engages in the dismantling holes so that the spring steel sheet can be pulled out of the retaining groove under pretension when the rotor is installed.

If several spring steel sheets are stacked one on top of the other, the dismantling bores are advantageously directly above one another, so that one tool can simultaneously engage in the dismantling bores of several spring steel sheets.

According to a further preferred embodiment, the Fi xierblech at least one centering tab, wherein the

Centering tab is bent in the radial direction so that it is in particular perpendicular to the rotor axis. The

The centering tab is a spatial limitation for the spring steel sheet in the axial direction. The centering tab extends in the direction of the spring steel sheet. Depending on the position of the fixing plate relative to the spring plate, the Zentrierla cal can thus be bent radially inward or radially outward.

The centering tabs are partially pre-bent when installing the fixing plate. Alternatively, it is also possible that these are only bent at their place of use. In a particularly advantageous manner, the centering tab also adjoins the protrusion of the spring steel sheet, ie the centering tab and the protrusion are located next to one another in a tangential direction. This interaction enables the spring plate to be centered in the tangential direction. For this purpose, the fixing plate preferably has two pre-bent centering tabs on the assembly side, which are adjacent to the two sides of the protrusion of the spring plate.

Furthermore, it is advantageous if at least one Zentrierla cal is arranged at each end of the fixing plate. This enables the spring steel sheet to be secured axially in both directions.

If both a fixing tab and a centering tab are advantageously arranged at one end of the fixing plate, the fixing tab extends radially opposite the centering tab. It can advantageously be provided that one bracket rests on one end face of the rotor blade and the other bracket rests on one end face of the blade carrier.

If a centering tab is advantageously arranged on the second side, this can also advantageously be located on an opposite end face of the rotor blade or the

The display support (depending on which side the spring plate is arranged).

In a first embodiment variant, at least one fixing tab is arranged on both sides of the fixing plate. In this case, it is provided for advantageous assembly that the fixing tab on the assembly side initially extends in the extension of the fixing plate. In this variant, it is necessary that the fixing strap is bent over after the rotor blade has been installed. In contrast to this, the one centering tab or both centering tabs arranged opposite and the fixing tab arranged opposite to the assembly side can already move into the radial one before assembly Extend direction and can thus be advantageously pre-bent.

In a second embodiment variant, the blade ring furthermore comprises a mounting plate which is arranged adjacent to the fixing plate and opposite to the spring plate. The mounting plate enables the axial fixation of the rotor blade in that at least one radially extending fixation tab is arranged on the assembly side. For this purpose, the mounting plate is advantageously mounted after the mounting of the blade and in this respect the fixing tab can also be formed in the end position before mounting.

In the advantageous arrangement of the fixing tab on the Mon day side both the fixing plate and the mounting plate is provided that the fixing plate stretches radially and rests against an end face of the blade or the blade carrier. If there is a centering tab on the same side, the fixing tab extends radially opposite one another. To simplify production, it can be provided that the at least one fixing tab and the at least one centering tab - if present - are arranged tangentially next to one another, so that production from a sheet metal section with subsequent bending is possible.

Preferably one or both of the fixing tabs is used directly to axially secure the rotor blade and is accordingly bent radially outward. Particularly in front of geous, the fixing tab is bent radially outward, that is to say towards the blade, and thus prevents undesired axial movement of the blade out of the retaining groove.

The locking of the mounting plate takes place in accordance with an advantageous embodiment in that the fixing plate in the axial direction Rich has at least one radially outwardly shaped locking tab, for which a corresponding pocket is provided on the mounting plate. Deformed when inserting the mounting plate the locking tab and engages in the end position of the mounting plate in the pocket of the mounting plate. As a result, the axial fixing of the mounting plate on the fixing plate is ben. It is obvious that, as an alternative, a reverse arrangement with the locking tab on the mounting plate and the pocket on the fixing plate is possible.

The object is also achieved according to the invention by a method for mounting a rotor blade on a blade ring as described above.

For this purpose, the at least one spring plate and the at least one fixing plate are first inserted in a simple manner one after the other (or vice versa, depending on the intended arrangement) radially from the outside into the holding groove. The first thing to do is to insert the sheet metal, which in the assembled state is arranged on the side facing the base of the retaining groove. Correspondingly, the assembly of the further sheet or sheets takes place below. Alternatively, the sheets can also be inserted as a package in the desired order.

The rotor blade is then pushed axially into the retaining groove. In contrast, it is not necessary to insert the Fi xierblech or the spring plate also axially into the retaining groove.

If a fixing plate is used which has a fixing tab on the assembly side to limit the axial movement of the blade, this fixing tab is advantageously bent after the blade has been pushed in.

If the advantageous mounting plate is used, there is no bending of the fixing tab. Rather, the backup is effected by pushing in the mounting plate after pushing the rotor blade. The object is finally achieved by a method for dismantling a rotor blade of such a blade ring.

For this purpose, the centering tab of the fixing plate is first bent open on the assembly side, so that the centering tab extends as an extension of the fixing plate. By bending the centering tab, the spring steel sheet is axially free.

The spring steel sheet can then be pulled out of the retaining groove. In the case of a spring steel sheet package made up of several spring steel sheets, all spring steel sheets are preferably pulled out simultaneously.

By removing the spring plate, a radial gap is created in the retaining groove and there is no radial preload on the blade. This makes it possible for the rotor blade to be pulled laterally out of the holding groove without great effort.

It is particularly advantageous if a tool is used to pull out the Fe derblechs, which engages in the demon day hole.

If there is an advantageous fixing tab on the assembly side with an abutment on the blade, it is advantageously provided that the fixing tab is first bent into the extension of the fixing plate before the blade is removed, and the blade is then dismantled.

Overall, the solution is characterized by a particularly simple method for removing the rotor blade.

Embodiments of the invention are explained in more detail with reference to a drawing. Show here: 1 shows, in an exploded view, sections of a blade ring according to the invention in the first embodiment;

FIG. 2 - FIG. 5 shows, step by step, the assembly of a rotor blade according to the second variant embodiment of a blade ring with mounting plate;

6 shows a view of an assembly side of the blade ring according to the second embodiment variant;

7 shows the metal sheets used in the second variant embodiment;

8 shows an alternative embodiment to the first embodiment variant;

9 shows an exemplary rear side of the blade ring.

FIG. 1 shows a section of a blade ring 2 for an axial turbo machine, not shown in detail, such as for a compressor of a gas turbine. The blade ring 2 comprises a blade carrier 6, not shown in detail here, with a plurality of retaining grooves extending in the axial direction A, of which only one retaining groove 8 is shown. A blade 10 is inserted into the retaining groove 8, with between the blade 10 and a retaining groove base 12 of the Hal tenut 8 fixing plate 16 for axially fixing the blade 10 is arranged. To achieve the desired radial tension of the blade 10 in the retaining groove 8, several spring plates 18 are used.

The fixing plate 16 is thicker than the spring plate 18 leads out. In particular, it has a thickness in the range between 2 mm and 3 mm. In addition, the fixing plate 16 is formed from a steel which has less deformation than the material of the spring plate, that is to say no spring steel. The fixing plate 16 can consist of X6CrNiTil810, for example. The fixing plate 16 is designed to be complementary to the underside of the rotor blade 10, a convex contact surface, and is in this respect a curved plate.

At one axial end, the fixing plate 16 has a centering tab 24 in the middle, which is bent radially inward. To the side of the centering tab 24, two fixing tabs 26 are provided which, in the assembled state, are bent radially outward (indicated with dashed lines). In this exemplary embodiment, the axial fixation of the rotor blade 10 is thus effected on the assembly side.

In the first exemplary embodiment shown, the spring steel sheets 18 are formed from a spring steel and have a thickness in the range between 0.4 mm and 0.5 mm. Spring steel is understood here to be a steel that has a higher strength compared to other steels. Such a steel is e.g. X10CrNil8. Due to the shape or the arrangement of the spring plates 18, a spring force acting radially outward on the rotor blade 10 is generated.

In the specific exemplary embodiment, the spring effect is created by the combination of flat spring steel sheets 18 and a concave retaining groove base 12 in conjunction with a convexly shaped fixing plate 16 pointing towards the spring steel sheets 18.

Alternatively, curved spring plates can be inserted between a flat retaining groove base and a flat fixing plate in order to generate the spring effect.

Each spring plate 18 has an axial Ausspa tion 20 and two dismantling bores 22 at its end. It can also be seen that the centering tab 24 on the fixing plate engages in the recesses 20 of the spring steel plates 18. As a result, on the one hand, an axial securing of the spring steel sheets 18 is effected and at the same time a centering in the tangential direction is made possible.

In the first exemplary embodiment shown, several spring plates 18 are provided, but it is possible to achieve the resilient effect by means of a single spring plate 18. On the other hand, it is also conceivable to use more than just one fixing plate 16, e.g. two or more plates with similar properties.

In addition, in the first exemplary embodiment the fixing plate 16 is arranged radially above the spring plate 18; alternatively, other arrangements are also possible, e.g. by inserting the fixing plate between the radially lowermost spring plate 18 and the retaining groove base 12.

The steps for assembling a rotor blade 10 in a retaining groove 8 according to a second variant are shown in FIG. 2 to FIG. The assembly in the end position of the rotor blade 10 is shown in FIG. The detailed structure of the components of the spring element can be seen from FIG.

As can be seen from FIG. 2, the spring steel sheets 18 are first inserted as a package in the radial direction R into the retaining groove 8 from the outside. The dismantling bores 22 of the individual spring plates 18 are always one above the other. Then the fixing plate 16 is also inserted radially from the outside. In this embodiment, two centering tabs 24 are provided on the assembly side and two centering tabs 25 are provided on the rear side, which are 24, 25 pre-bent radially inward. Furthermore, the fixing plate comprises a fixing tab 27 which is arranged on the rear side and is oriented radially outward. As can still be seen, the xierblech 16 formed, shown in more detail in Figure 7 Rastla's 28 out of the plane of the fixing plate 16 radially outward.

The rotor blade 10 is inserted axially into the retaining groove 8 from an assembly side 30, which is shown in FIG.

Finally, as shown in FIG 4, a mounting plate 32 axially between tween the fixing plate 16 and the blade 10 is pushed in. Over part of the axial length of the mounting plate 32, two pockets 34 are formed which correspond to the locking tabs 28 of the fixing plate 16, so that the locking tabs 28 snap into pockets 34, which can be seen from FIG. On the assembly side, the mounting plate 32 has two ra dial outwardly extending fixing tabs 26, which 26 come to rest on an end face of the rotor blade 10.

The assembly side 30 of the finished assembly according to FIG. 2 to FIG. 5 is shown in FIG. The spring plate 16, a fixing plate 18 and the mounting plate 32 are shown in greater detail individually in FIG. In FIG. 6, the lateral centering tabs 24 of the fixing plate 16 are bent inward in the radial direction R and engage in corresponding recesses 20 of the spring steel plates 18. The centering tabs 24 encompass an overhang 33 of the spring steel plate 18 protruding from the retaining groove 8, in which 33 the mounting holes 22 are formed.

In FIG. 7, the mounting plate 32, the fixing plate 16 and a spring plate 18 are sketched at a distance from one another, the blank of a respective metal sheet being sketched before the tabs 24-28 are bent.

A variant of the first exemplary embodiment is shown in FIG. 8 and FIG. 8 shows the assembly side 30 of the blade rim 2. The fixing plate with two radially inwardly bent centering tabs 24 and a radially outwardly bent fixing plate can be seen under the rotor blade 10. see 26. The protrusion 33 of the spring plate with the disassembly bore extends between the centering tabs 24. The fixing tab 26, which is formed on the fixing plate 16, is only folded over radially outward after the rotor blade 10 has been inserted and supports the rotor blade 10 in the axial direction A.

The axially opposite rear side 36 is sketched in FIG. A similar structure with two centering tabs 25 and a fixing tab 27 is present on the rear side 36. However, there is no protrusion with a disassembly hole on the spring plate.

To dismantle a blade ring arrangement according to one of the examples outlined, the centering tabs 24 are first bent open on the assembly side 30 so that these 24 extend as an extension of the fixing plate 16. Thereafter, a tool, in particular a hook-shaped tool, is introduced from the assembly side 30 into the disassembly bores 22 of the Fe derbleche 18, with the aid of which the spring plates 18 are pulled out of the retaining groove 8 laterally. As a result, a radial spring force is no longer exerted on the rotor blade 10. The fixing tab 26 is now bent open on the assembly side 30, so that the rotor blade 10 can subsequently be removed axially from the retaining groove 8 without any problems.

Claims

1. Blade ring (2) for an axial turbo machine with a blade carrier (6), which (6) has several retaining grooves (8) running in the axial direction with a respective retaining groove base (12), and with a rotor blade (10) which ( 10) are each inserted in a retaining groove (8) and have a bearing surface facing the retaining groove base (12), and with fixing plates (16) which (16) are each arranged between the bearing surface and the associated retaining groove base (12) and on both ends extend beyond one end face of the blade carrier (6) and / or the rotor blade (10) and have at least one fixing tab (26, 27) extending in the radial direction on at least one end,

marked by

at least one spring plate (18) which (18) is arranged between tween the fixing plate (16) and the contact surface or the retaining groove base (12) and causes a radially acting de spring force.

2. blade ring (2) according to claim 1,

the fixing plate (16) having a thickness less than 0.2 times its width, and in particular between 1 mm and 4 mm; and or

wherein the fixing plate (16) is made of a flat material Herge provides.

3. blade ring (2) according to claim 1 or 2,

wherein the length of the spring plate (18) is at least

0.8 times the length of the fixing plate (16) corresponds;

and or

the spring plate (18) having a thickness less than 0.1 times its width, and in particular between 0.2 mm and 0.7 mm; and or

wherein the spring plate (18) is made from a flat material, and in particular is made flat.

4. blade ring (2) according to one of claims 1 to 3, wherein at least two spring plates (18) are arranged radially one above the other.

5. blade ring (2) according to one of claims 1 to 4,

wherein in a cross section the contact surface is convex and / or the retaining groove base (12) is concave, and in particular the fixing plate is shaped complementary to the contact surface (11) and / or the retaining groove base (12).

6. blade ring (2) according to one of claims 1 to 5,

wherein the spring plate (18) at at least one end, in particular at both ends, with a protrusion (33) in sections axially over an end face of the blade carrier (6) and / or the rotor blade (10) it extends.

7. blade ring (2) according to claim 5,

wherein the spring plate (18) has at least one dismantling bore (22) in the protrusion (33).

8. blade ring (2) according to claim 7,

wherein the fixing plate (16) at least at one end, in particular at both ends, has at least one radially stretching centering tab (24) which (24) forms an axial limit for the spring plate (18), and in particular in cooperation with the Overhang (33) effect a tangential centering of the spring plate (18).

9. blade ring (2) according to one of claims 1 to 8,

wherein the fixing plate (16) has at least one fixing tab (26) pointing away radially from the spring plate (18) at both ends.

10. blade ring (2) according to one of claims 1 to 8,

marked by

a mounting plate (32) which is arranged adjacent to the fixing plate (16) opposite to the spring plate (18).

11. blade ring (2) according to claim 10,

the mounting plate (32) having at least one radially extending fixing plate (26) at the end opposite the fixing tab (26) on the fixing plate (16).

12. blade ring (2) according to claim 10 or 11,

wherein the mounting plate (32) has at least one pocket (34) and the fixing plate (16) has at least one latching tab (28) resiliently engaging in the pocket (34), or the fixing plate (16) has at least one pocket (34) and the mounting plate (32) has at least one latching tab (28) resiliently engaging in the pocket (34),

whereby an axial fixation of the mounting plate (32) on the fixing plate (16) takes place.

13. A method for mounting a rotor blade (10) on a blade ring (2) according to one of the preceding claims, comprising the steps:

- Insertion of the fixing plate (16) and the at least one spring plate (18) into the holding groove (8); and

- Push the blade (10) into the retaining groove (8).

14. The method according to claim 13,

wherein the fixing tab (26) on the side of the blade to be pushed (10) first extends in the extension of the fixing plate (16) and after pushing the blade (10) is bent radially outward.

15. The method according to claim 13,

wherein the mounting plate (32) is pushed into the retaining groove (8) after the rotor blade (10) has been pushed in.

16. A method for dismantling a rotor blade (10) of a blade ring (2) according to one of claims 1 to 12 with the steps:

- Bending the centering tab (24) into the extension of the fixing plate (16);

- Axial withdrawal of the spring steel sheet (18) from the Hal tenut (8); and

- Axial withdrawal of the blade (10) from the Hal tenut (8).

17. The method according to claim 16,

a tool that engages in the disassembly bore (22) is used to pull out the spring plate (18).

18. The method according to claim 16 or 17,

wherein prior to dismantling the blade (10), the fixing tab (26) is bent on one assembly side into the extension of the fixing plate (16).