CN114599859A

CN114599859A - Rotor with a rotor component arranged between two rotor disks

Info

Publication number: CN114599859A
Application number: CN202080073026.2A
Authority: CN
Inventors: 彼得·库里; 米尔科·米拉扎尔; 克里斯托弗·W·罗斯; 尤利安·巴加埃娃; 卡斯滕·科尔克; 伊凡·勒博夫; 亚历山大·罗曼诺夫; 哈拉尔德·赫尔; 凯文·肯扑卡; 勒内·曼克; 安德烈亚斯·弗瑞真; 丹尼尔·霍夫索默; 埃克哈德·马尔德费尔德; 约格·里克特
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2019-10-18
Filing date: 2020-06-18
Publication date: 2022-06-07
Anticipated expiration: 2040-06-18
Also published as: CN114599859B; JP7394979B2; EP4013950B1; WO2021073786A1; JP2022552170A; KR20220078706A; EP4013950A1

Abstract

The invention relates to a rotor of a gas turbine, comprising two adjacent rotor disks (01, 11) on which rotor blades are respectively fastened, wherein an annular rotor component (21) is arranged between the rotor disks (01, 11), which rotor component has circumferential annular grooves (24, 34) on opposite ends, into which circumferential fastening projections (04, 14) of the respective rotor disks (01, 11) engage respectively. In the rest state of the rotor, the first groove outer side (25) of the first annular groove (24) bears under pressure against the first projection outer side (05) of the first fastening projection (04), and a gap is present between the first groove inner side (26) of the first annular groove (24) and the first projection inner side (06) of the first fastening projection (04).

Description

Rotor with a rotor component arranged between two rotor disks

Technical Field

The invention relates to a rotor of a gas turbine, comprising at least two rotor disks connected to one another, between which an annular rotor component is arranged.

Background

Different embodiments of rotors with interconnected rotor disks for use in gas turbines are known from the prior art, wherein an annular rotor component is arranged between the rotor disks for shielding an inner region of the rotor from hot gas flowing through the gas turbine. In this case, the two rotor disks have a plurality of rotor blades distributed over the outer circumference in each case. Between the two rows of rotor blades there is a row of guide blades arranged distributed around the circumference, which are each fastened to a stationary housing. In this case, a gap must exist between the guide blades and the rotor blades due to the rotation of the rotor. The gap can in principle allow the hot gas to enter radially into the region inside the stator blade. In order to keep the hot gas away from the rotor interior, in some gas turbines an annular rotor component is provided between two adjacent rotor disks. For this purpose, the rotor components are supported on both sides of the rotor disk.

The rotor component is solely based on the object of being able to prevent hot gas ingress. The other function is not normally present. Accordingly, the mounting of the rotor component is generally kept simple, with only one annular, axially extending shoulder engaging in a corresponding annular groove.

In order to ensure the position of the rotor components between the two rotor disks, it is generally proposed: the rotor components are supported on both sides of the respective rotor disk by means of a press fit. Here, the rotor component is usually arranged on the side facing the rotor axis relative to the rotor disk at the location of the press fit. This is due in particular to the fact that the rotor components are subjected to greater deformations in the event of centrifugal forces than rotor disks which are formed in a solid manner in comparison therewith.

Although the usual embodiments in the prior art have proven successful, it is therefore possible for different thermal expansions to occur at the rotor disk and at the rotor components, depending on the design of the press fit and the possible elastic deformations during heating or cooling of the gas turbine. In some cases, this can lead to: loss of compressive stress in the press fit. In contrast, the combination of the press fit provided and the deformation caused by the centrifugal force generated by the rotation of the rotor can lead to unacceptably high compressive stresses.

Disclosure of Invention

The object of the invention is therefore to ensure the position of the rotor component even when the gas turbine is heated and cooled, without exceeding the permissible stresses on the rotor component or the rotor disk.

The object is achieved by an embodiment according to the invention of a rotor according to the teaching of claim 1. Advantageous embodiments are the subject matter of the dependent claims. A method of mounting a rotor is given in claim 10.

This type of rotor was originally used in gas turbines. However, it is also possible, independently of this, to use the rotor embodiment in another turbomachine, for example in a steam turbine.

The rotor has at least a first rotor disk and a second rotor disk directly and securely connected to the first rotor disk. In this case, the rotor disks each have a plurality of blade retaining grooves distributed over the outer circumference, which each extend axially through the respective rotor disk. In this case, the blade holding groove serves to accommodate the rotor blade.

In addition, the first rotor disk has a circumferential first fixing projection radially below the blade retaining groove, said first fixing projection extending in the axial direction toward the second rotor disk. Similarly, the second rotor disk has a circumferential second fixing projection radially below the blade retaining groove, which second fixing projection extends in the axial direction toward the first rotor disk.

An annular rotor component is arranged in the region of the blade retaining groove and/or between the two rotor disks radially below the blade retaining groove. The annular rotor component surrounds a section of the rotor or of the two rotor disks whose section is located inside the rotor component. For centering and simultaneously fixing the rotor component relative to the rotor disk, the rotor component has a circumferential, axially open first annular groove at an axial end and a circumferential, axially open second annular groove axially opposite thereto. In this case, the first fastening projection of the first rotor disk engages in the first annular groove, and the second fastening projection of the second rotor disk engages in the second annular groove.

According to the invention, a defined position of the rotor component is now ensured without unacceptably high stresses occurring in that: in a stationary state where the rotor of the rotor has substantially room temperature, a compression is provided on the outer circumference of the first fixing projection. Accordingly, the first groove outer side of the first annular groove bears against the first projection outer side of the first fastening projection under pressure. Contrary to this, the requirements are: when at rest at room temperature, a gap is present between the first groove inner side of the first annular groove and the first projection inner side of the first fastening projection (04) in a radially opposing manner.

By the arrangement according to the invention of the press fit when the rotor is in the rest state, in which the rotor as a whole has room temperature, on the radial outside of the first rotor disk with respect to the fixing projections, an inadmissible increase in the compressive stress is avoided when centrifugal forces occur.

It is particularly advantageous here that the connection of the rotor component to the second rotor disk is substantially stress-free when the rotor is at rest at room temperature. For this purpose, it is necessary for a gap to be present between the second groove outer side of the second annular groove and the second projection outer side of the second fastening projection, and for a gap to be present between the second groove inner side of the second annular groove and the second projection inner side of the second fastening projection.

With regard to the advantageous coordination of the fixing of the rotor components between the rotor disks and the compressive stresses which occur in consideration of the rotation of the rotor at the start-up of the gas turbine and the accompanying expansion of the rotor components and the rotor disks, it is particularly advantageous if, in a first transitional state at a first rotational speed of the rotor, a change occurs from the first rotor disk to the fixed state of the second rotor disk. In this case, the first rotational speed is lower than the nominal rotational speed at which the rotor operates according to regulations. In this first transitional state, the contact of the first groove outer side against the first projection outer side is not reduced, wherein the second groove inner side also contacts the second projection inner side. In contrast, the gap between the first groove inner side and the first projection inner side and the gap between the second groove outer side (35) and the second projection outer side remain unreduced.

In this case, the first rotational speed is advantageously greater than 0.2 times the nominal rotational speed. In contrast, the design should provide that the first rotational speed is less than 0.6 times the nominal rotational speed. For the design of the transition state, it can be assumed that the rotor disk and the rotor component have approximately the same temperature, which corresponds approximately to or is above room temperature, but differs significantly from the operating temperature.

The position of the rotor component relative to the rotor disk during the start-up of the gas turbine can be advantageously ensured by a corresponding determination of the diameter of the opposing fixing projections and of the annular groove. As the rotational speed of the rotor component relative to the rotor disk increases and expands relatively more, the pressing force between the first projection outer side and the first groove outer side decreases, wherein contact is produced between the second groove inner side and the second projection inner side. In this respect, in the first transition state, the fixing of the rotor component to the first rotor disk changes to the fixing of the rotor component to the second rotor disk.

In a second transitional state, at a second rotational speed of the rotor, the fixation of the rotor component is advantageously undertaken by the second rotor disk. In this case, the second rotational speed is higher than the first rotational speed, but lower than the nominal rotational speed of the gas turbine. Accordingly, there is compression between the second groove inner side and the second projection inner side. In contrast, there is a gap between the further contact surfaces, i.e. between the first groove outer side and the first projection outer side, and between the first groove inner side and the first projection inner side, and between the second groove outer side and the second projection outer side.

In order to design the second transition state, a second rotational speed can advantageously be assumed, which corresponds to at least 0.8 times the nominal rotational speed.

In the second transition state, the component has a second transition temperature. At startup of the gas turbine and when all components are heated, the particularly low mass of the rotor components typically heats up significantly faster than the more solid rotor disks. Accordingly, the second transition temperature is characterized in that the rotor component approximately reaches the operating temperature, while the rotor disk has a significantly lower temperature than the operating temperature, for example a temperature which is approximately 30% lower.

It is particularly advantageous if the rotor component is supported on both sides at the rated rotational speed according to the specification for a firm bearing of the rotor component between the two rotor disks and for the rotor component to be supported on the rotor disks. For this purpose, the first groove inner side is pressed against the first projection inner side, and the second groove inner side is pressed against the second projection inner side. In contrast, there are gaps on the radial outside, i.e. between the first groove outer side face and the first projection outer side face and between the second groove outer side face and the second projection outer side face. Thus, a safe position of the rotor member and load absorption of the centrifugal force are ensured on both sides.

Advantageous mounting of the rotor component in the rotor can be achieved if the diameter of the first annular groove is determined in a suitable ratio to the diameter of the first fixing projection. In this case, it is particularly advantageous for the mounting to heat the rotor component to a mounting temperature of at least 100 ℃ and at most 200 ℃, whereas the rotor disk has room temperature. The required size of the first annular groove relative to the first fixing projection can be determined taking into account the corresponding expansion of the rotor component due to the temperature increase. In this case, it is advantageous if, at the installation temperature, the pressing force between the outer side of the first groove and the outer side of the first projection corresponds to a maximum of 10% of the pressing force between the two components at room temperature. In this case, it is particularly advantageous if the diameters of the fastening projection and of the annular groove are designed accordingly, so that the overlap existing at room temperature is substantially eliminated by means of the installation temperature.

If a gap is produced between the first groove outer side and the first projection outer side at the installation temperature, it is to be noted in contrast thereto that, however, no significant overlap is produced on the radial inner side. Accordingly, the pressing force between the first groove inner side and the first projection inner side can in this case be a maximum of 10% of the pressing force existing at room temperature between the first groove outer side and the first projection outer side. In any case, it is advantageous if a gap is maintained between the first groove inner side and the first projection inner side even at the installation temperature.

In an advantageous embodiment of the rotor component, the rotor component has a cover section, by means of which the blade retaining groove or the blade root of the rotor blade fixed in the blade retaining groove can be covered at least in sections. For this purpose, the cover segments need to extend in the circumferential direction and in the radial direction. The cover section is arranged here on the radial outside of the first annular section groove. It is also proposed that the cover section in the region between the blade retaining grooves bears axially against the end face of the first rotor disk by means of a bearing surface.

In a particularly advantageous manner, it can be provided that the rotor component has cover sections on both sides, axially opposite one another.

It is also advantageous at least if the support surface bears against the end face under compression when the cover section is elastically deformed. It is thus possible to ensure: in the case of operation of the fluid machine at operating temperatures from rest up to the rated rotational speed, the support surface is in any case in contact with the end face.

In order to achieve an advantageous pressing between the support surface and the end surface while avoiding an increase in the mounting force, it can advantageously be provided that the rotor component is heated to a mounting temperature of between 100 ℃ and 200 ℃, which is accompanied by a deformation of the rotor component and in particular of the cover section, such that, in a defined position of the rotor component in the region of the annular groove relative to the fastening projection, the pressing force between the support surface and the end surface corresponds to a maximum of 10% of the pressing force at room temperature. This state of deformation of the cover segments in the axial direction, in particular in the region of the bearing surfaces, is achieved, on the one hand, by the configuration of the rotor component with cover segments arranged on the axial ends. Furthermore, a configuration with a lower material thickness in the central region between two annular grooves has an advantageous effect with regard to the desired deformation. On the other hand, the desired effect can be achieved by a targeted temperature increase, preferably in the region of the first annular groove.

In consideration of the possible installation temperatures of the rotor components, the respective configuration of the rotor components, in particular the diameters of the first and second annular grooves and the overlap between the bearing surfaces and the end faces, is determined, on the one hand, so that installation can be carried out without excessive expenditure of force and the secure position of the rotor components between the rotor disks is determined during operation.

It is also advantageous if, during the mounting of the rotor component on the first rotor disk, a free first expansion distance is maintained between the first projection end face of the first fastening projection and the first groove base of the first annular groove. The first expansion distance is here at least 0.5 mm. In contrast, the first expansion distance is disadvantageously greater than 5 mm. Particularly advantageous is a first expansion distance of at least 1mm and at most 2.5 mm.

It can also be provided that a second expansion distance exists between the second projection end face of the second fastening projection and the second groove base of the second annular groove. In this case, the second expansion distance should correspond to a maximum of 0.2 times the first expansion distance.

The novel configuration of the rotor component with regard to its fixation between two adjacent rotor disks leads to a novel method for mounting the rotor.

First a first rotor disc is provided. It is advantageous here for the first rotor disk to be mounted horizontally, with its rotor axis oriented vertically.

The rotor component must be heated to a mounting temperature of at least 100 ℃ here or later. In this case, the temperature should not exceed 200 ℃.

The rotor component is now placed on the first rotor disk. To this end, the rotor member is placed on the first rotor disc such that the first annular groove is located above the first fixing projection. The rotor component can thus be pressed onto the first rotor disk until the bearing face abuts against the end face of the rotor disk.

By pushing the rotor component further onto the first rotor disk by means of elastic deformation of the rotor component, a desired position of the rotor component relative to the rotor disk is reached, wherein the desired position is defined by a predefined first expansion distance between the first projection end face of the first fixing projection and the first groove bottom of the first annular groove.

Now, the rotor component can be cooled, wherein during this time the rotor component has to be held in position relative to the first rotor disk.

Finally, the second rotor disk can be placed or pressed onto the first rotor disk and the rotor component simultaneously. The second fastening projection engages in the second annular groove.

Drawings

Exemplary embodiments of the rotor according to the invention are illustrated in the following figures. The figures show:

fig. 1 schematically shows a rotor component between two rotor disks in a sectional view;

FIG. 2 shows a detail of the press fit between the first fixing protrusion and the first annular groove;

FIG. 3 shows a detail of the gap between the second fixing lug and the second annular groove;

4-7 illustrate displacement of a rotor component relative to a rotor disk upon startup of a gas turbine;

fig. 8-11 illustrate the mounting of the rotor member on the first rotor disk.

Detailed Description

The mounting of the rotor component 21 between the

rotor disks

01 and 11 is schematically illustrated in fig. 1 in a sectional view. The

rotor disks

01, 11 in this case each have

blade retaining grooves

02, 12, which extend axially through the

respective rotor disk

01, 11, distributed over the outer circumference. The

blade retaining grooves

02, 12 are defined for receiving rotor blades. The

respective rotor disks

01, 11 in turn each have a

fastening projection

04, 14, which surrounds the rotor axis 10. As can be seen, the

fastening projections

04, 14 each extend axially to the opposing rotor disk. The rotor component 21 located between the two

rotor disks

01, 11 covers the intermediate space between the

rotor disks

01, 11. For fastening, the rotor component 21 has

annular grooves

24, 34 on axially opposite sides, in each case, into which annular grooves 24, 34 a

respective fastening projection

04, 24 engages. Furthermore, a cover section 22 can be identified at an axial end of the rotor component 21, said cover section 22 extending in the circumferential direction and in the radial direction. The cover section 22 covers the blade retaining groove 02 in the first rotor disk.

The detail of the press fit between the first fixing projection 04 and the first annular groove 24 is drawn in fig. 2. For better visibility, the rotor components 21 are shown offset axially. The first rotor disk has a first projection outer side 05 on the first fastening projection 04 on the radial outside. The first inner lobe side 06 is located on a diametrically opposite side. The first projection end face 07 is located at the free end of the first fixing projection 04. Similarly, the rotor component 21 has a first groove outer side 25 on the radial outer side and a first groove inner side 26 on the radial inner side at the first annular groove 24. A first groove base 27 is present on the annular groove 24 opposite the first projection end face 07. There is a press fit between the first projection outer side surfaces 05 and the first groove outer side surfaces 25 in a stationary state of the rotor at normal temperature or after the rotor is mounted. The press fit results from a geometric overlap 08 between the two

respective components

01, 21. On the radially opposite inner side, a gap 28 is present between the first projection inner side and the first groove inner side.

Fig. 3 shows a detail of the assembly between the second rotor disk 11 and the rotor component 21, wherein the rotor components 21 are shown offset, similar to fig. 2. In turn, it can be recognized that the second rotor disk 11 essentially has blade retaining grooves 12 and second fixing projections 14. The rotor disk 14 has a radially outer second projecting outer side 15 and a radially opposite second projecting inner side 16, and has a second projecting end face 17 on the end face. For this purpose, a second groove outer side 35 and an opposing second groove inner side 36 are present on the rotor component 21 on the second annular groove 34 on the radial outside, and a second groove bottom 27 is present opposite the second projection end face 17. It can be recognized here that, in the rest state or after installation,

gaps

09, 29 are present between the second fixing lug 14 and the second annular groove 34 on the radial outside and on the radial inside.

Fig. 4 to 7 below show the state of the rotor component 21 mounted on the two

fastening projections

04, 14 during the start-up of the gas turbine and the increase in rotational speed to the nominal rotational speed ω N and the increase in temperature to the operating temperature TN.

The state after installation or in the rest state is depicted in fig. 4 as described above. On the first rotor disk 01, due to the overlap 08, a press fit is present on the radial outside, whereas on the contrary a gap 28 is present on the radial inside. Likewise,

free gaps

09, 29 are present on both sides of the second fixing projection 14.

Fig. 5 now shows a first transitional state during the start-up of the gas turbine. If the rotor is now set in motion, a first rotational speed ω 1 is reached, which first rotational speed ω 1 is still significantly lower than the nominal rotational speed ω N, wherein the component temperatures T01, 11, 21 of the

rotor disks

01, 14 and of the rotor components can be slightly increased, however still far away from the operating temperature TN. It is important that in the first transitional state, the second groove inner side 36 now rests against the second projection inner side 16. Depending on the temperatures T01, 11, 21 of the

components

01, 11, 21 and the existing gap 29 in the stationary state, the contact is carried out at different rotational speeds, wherein the gap 29 is preferably determined to be a value which causes contact at a nominal rotational speed ω N of about 0.3.

As the rotational speed increases and the component temperature increases, the contact pressure between the second fixing projection 14 and the rotor component 21 increases on the radial inner side, whereas the contact pressure between the first fixing projection 04 and the rotor component 21 decreases on the radial outer side. In the second transitional state depicted in fig. 6, a gap is now produced on the radial outside between the first fastening projection 04 and the rotor component 21. That is, a free space exists between the first projection outer side surface 05 and the first groove outer side surface 25. In this state, the second rotational speed ω 2 lies between the first rotational speed ω 1 in the first transition state and the nominal rotational speed ω N, wherein the second rotational speed ω 2 can correspond to about 0.6 times the nominal rotational speed ω N. Due to the smaller mass of the rotor component 21 relative to the

rotor disks

01, 11, the gas turbine heats up more quickly when it is started up. Accordingly, the component temperature T01, 11 of the

rotor disks

01, 11 is significantly lower than the component temperature T21 of the rotor components, which component temperature T21 gradually approaches the operating temperature TN.

Fig. 7 shows the state when the nominal rotational speed ω N and the operating temperature TN are reached. From the second transitional state of the rotational speed increase, the first inner flank 06 of the first fastening projection 04 bears against the first inner flank 26 of the first annular groove 24.

The mounting of the rotor member 21 on the first rotor disc 01 is schematically illustrated in the following fig. 8 to 11. It is to be noted here that for advantageous mounting, the rotor disk 01 is oriented vertically, not horizontally as shown here, and correspondingly the rotor component 21 is located above the rotor disk 01. As mentioned above, it is provided that an overlap 08 exists between the first projection outer side surface 05 of the first fastening projection 04 and the first groove outer side surface 25 of the first annular groove 24, so that a press fit results. Furthermore, it is proposed that the cover portion 22 rests with the support surface 23 against the end face 03 of the rotor disk 01 under pressure. This requires heating of the rotor member 21 for advantageous mounting.

For this purpose, fig. 8 shows the state of the rotor disk 01 and the rotor component 21 located above it, wherein the rotor component 21 is preheated to a temperature between 100 ℃ and 200 ℃. Thus, on the one hand: the diameter of the first groove outer side 25 is increased at least approximately to the diameter of the first projection outer side 05, whereby it is possible to push the rotor member 21 onto the first fixing projection 04 without excessive force.

However, a further effect is achieved by the special shaping of the rotor component 21 during heating. This effect is a deformation of the rotor member 21 as follows: the cover section 22 is deformed away from the first rotor disc 01. Accordingly, the distance between the end face 03 and the support face 23 increases, contrary to the case at room temperature.

For this purpose, fig. 9 shows the position of the rotor component 21 on the rotor disk 01 until the rotor component 21 comes into contact with the end face 03 before the bearing face 23 comes into contact with it. In this case, an increased expansion distance 33' remains between the first projection end face 07 and the first groove base 27.

The rotor component 21 is then pressed further onto the first fastening projections 04 of the first rotor disk 01 until the previously defined expansion distance 33 is reached — see fig. 10. The cover segment 22 continues to deform, wherein an initial compression occurs between the support surface 23 and the end face 03.

Fig. 11 now shows the state of the rotor member 21 when it is cooled again, as from the desired position shown in fig. 10. It is to be noted here that the expansion distance 33 is kept constant. The temperature-induced deformation of the cover section 22 now remains as a geometry-induced deformation, with a compression between the support surface 23 and the end face 03. The theoretical state with an overlap 13 between the rotor component 21 and the rotor disk 01 is plotted in fig. 11.

List of reference numerals:

01 first rotor disc

02 first blade holding groove

03 end face

04 first fixing projection

05 outer side of the first projection

06 first convex inner side surface

07 first raised end face

08 are overlapped

09 gap

10 rotor axis

11 second rotor disk

12 second vane retaining groove

13 overlap

14 second fixing projection

15 second convex outer side surface

16 second convex inner side surface

17 second convex end face

21 rotor component

22 cover section

23 bearing surface

24 first annular groove

25 first groove outer side surface

26 first groove inner side surface

27 first groove bottom

28 gap

29 gap

33 expansion gap

34 second annular groove

35 outer side of the second groove

36 second groove inner side surface

37 second groove bottom

Claims

1. A rotor, in particular for a gas turbine, having

A first rotor disk (01), which first rotor disk (01) has a plurality of first blade retaining grooves (02) which extend axially through the rotor disk (01) and a circumferential, axially extending first fastening projection (04) which is arranged below the first blade retaining grooves (02) on the side facing the rotor axis, distributed over the outer circumference, and

a second rotor disk (11), which second rotor disk (11) is firmly connected to the first rotor disk (01) and has, distributed over the outer circumference, a plurality of second blade retaining slots (12) which axially extend through the rotor disk (11) and a circumferential, axially extending second fixing projection (14) which is arranged below the second blade retaining slots (12) on the side facing the rotor axis, and

an annularly encircling rotor component (21), the rotor component (21) having an encircling, axially open first annular groove (24) on one side and an encircling, axially open second annular groove (34) on the opposite side, wherein the first fastening projection (04) engages in the first annular groove (24) and the second fastening projection (14) engages in the second annular groove (34),

it is characterized in that the preparation method is characterized in that,

in a static state

-a first groove outer side (25) of the first annular groove (24) bears under compression against a first projection outer side (05) of the first fixing projection (04), and

-a gap is present between the first groove inner side (26) of the first annular groove (24) and the first protrusion inner side (06) of the first fixing protrusion (04).

2. The rotor of claim 1,

in the rest state

-a gap is present between a second groove outer side (35) of the second annular groove (34) and a second projection outer side (15) of the second fixing projection (14), and

-a gap is present between the second groove inner side (36) of the second annular groove (34) and the second projection inner side (16) of the second fixing projection (14).

3. The rotor of claim 2,

in a first transitional state in which the first rotational speed is lower than the nominal rotational speed according to the specification, in particular the first rotational speed lies between 0.2 and 0.6 times the nominal rotational speed,

-the first groove outer side (25) bears against the first projection outer side (05), and

-a gap is present between the first groove inner side (26) and the first protrusion inner side (06), and

-there is a gap between the second groove outer side (35) and the second projection outer side (15), and

-the second groove inner side (36) bears against the second projection inner side (16).

4. The rotor of claim 3,

in a second transitional state in which the second rotational speed is greater than the first rotational speed and less than the nominal rotational speed according to the specification, in particular the second rotational speed is at least 0.8 times the nominal rotational speed,

-there is a gap between the first groove outer side (25) and the first projection outer side (05), and

-the second groove inner side (36) bears against the second projection inner side (16) under compression.

5. Rotor according to claim 1 or 4, characterised in that at a nominal rotational speed according to the specification

-there is a gap between the first groove outer side (25) and the first projection outer side (05),

-the first groove inner side (26) bears against the first projection inner side (06) under compression, and

6. The rotor of claim 1 or 5,

at a mounting temperature of the rotor component (21) of at least 100 ℃ and at most 200 ℃,

-the pressing force between the first groove outer side (25) and the first projection outer side (05) corresponds to a maximum of 10% of the pressing force at room temperature, and

-the pressing force between the first groove inner side (26) and the first projection inner side (06) corresponds to a maximum of 10% of the pressing force between the first groove outer side (25) and the first projection outer side (05) at room temperature, in particular a gap exists between the first groove inner side (26) and the first projection inner side (06).

7. The rotor according to one of claims 1 to 6, characterized in that the rotor component (21) has a circumferentially and radially extending cover section (22), which cover section (22) covers the first blade retaining groove (02) at least in sections and rests with a support surface (23) on the end face (03) of the first rotor disk in the region between the blade retaining grooves (02).

8. The rotor of claim 7,

the support surface (23) bears against the end face (03) under pressure when the cover section (22) is elastically deformed.

9. The rotor as recited in claim 8, characterized in that the pressing force of the support surface (23) against the end face (03) corresponds to a maximum of 10% of the pressing force at room temperature at a mounting temperature of the rotor component (21) of at least 100 ℃ and at most 200 ℃.

10. The rotor of any one of claims 1 to 9,

after the rotor has been installed, at least before the rotor is heated, a free first expansion distance exists between the first projection end face (07) of the first fastening projection (04) and the first groove base (27) of the first annular groove (24), wherein the first expansion distance is at least 0.5mm and at most 5mm, in particular at least 1mm and at most 2.5 mm.

11. The rotor as recited in claim 10, characterized in that a free second expansion distance or abutment exists between the second projection end face (17) of the second fixing projection (14) and the second groove bottom (37) of the second annular groove (34), wherein the second expansion distance corresponds at most to 0.2 times the first expansion distance.

12. A method for mounting a rotor according to any preceding claim, the method comprising:

-providing a first rotor disc (01);

-heating the rotor member (21) to a mounting temperature of at least 100 ℃ and at most 200 ℃;

-placing and/or pressing the rotor member (21) onto a first rotor disc (01), wherein the support surface (23) abuts against the end surface (03);

-pushing the rotor member (21) further onto the first rotor disc (01) until a predefined expansion distance between a first protrusion end surface (07) of a first fixing protrusion (04) and a first groove bottom (27) of the first annular groove (24) is reached;

-cooling the rotor member (21) and here holding the first rotor disc (01) and the rotor member (21) together;

-placing and/or pressing the second rotor disc (11) simultaneously onto the first rotor disc (01) and the rotor member (21).