EP1698758B1 - Axially split rotor end piece - Google Patents

Description

Technical area

The invention relates to the field of thermal turbomachinery, in particular it relates to a rotor end for rotors according to the preamble of claim 1. Furthermore, an assembly method for a rotor according to the invention is given.

State of the art

Thermal turbomachinery with axial turbines and axial compressors, have a rotor equipped with blades and a stator, are mounted in the guide vanes for flow guidance.

The stationary guide vanes have the task of directing the flow of the gas medium to be compressed or to be relaxed in such a way onto the rotating running blading of the respective compressor stage or the respective turbine stage that the energy conversion takes place with the best possible efficiency.

Both blades and vanes essentially comprise a profiled airfoil and a blade root. In order to secure the blades on the rotor or the stator vanes in the stator, grooved in the stator and on the rotor shaft. In these grooves are the Feet of the blades inserted and locked there.

It is known that compressor blade rows of gas turbine rotors are arranged in circumferential grooves, which often have a T-shaped cross-section. As a rule, blades and spacers alternate here. When assembling such rows of blades, a special solution must be found for the last blades to be mounted, since then the remaining filling opening for a complete intermediate piece is too small. This residual opening is therefore filled with a so-called rotor-end.

From the DE 812 337 is such a rotor-end known. The known rotor closure consists of a halved intermediate piece, that is to say of two halves split circumferentially with respect to the rotor, and a wedge with the aid of which the end halves in the rotor are caulked in the circumferential direction.

The two end halves in the known prior art according to the DE 812 337 each have a straight side surface formed. The side surfaces mentioned are opposite in the installed state, in which case the wedge is located between them. After the two end halves and the wedge are installed, finally, the formed at the top of the wedge flaps are bent into appropriate undercuts in the side surfaces of the end halves and the wedge and thus the entire tail secured against escaping.

A disadvantage of this prior art that at high rotor speeds strength problems due to the tilting moment of the two end halves can occur, which is caused by the centrifugal force during operation.

Another disadvantage of these technical solutions is that the On the one hand by the centrifugal force during operation and on the other hand by caulking of the wedge exert axial forces on the rotor. In the search for the causes of the frequently occurring rotor vibrations, it has been found that these axial forces can bend the rotor and thereby disadvantageously generate disturbing vibrations.

The EP 1 215 367 A2 and the DE 103 10 432 A1 describe proposals for solutions in which the forces are introduced into the adjacent blades, ie in the circumferential direction. The solutions presented here are complex and costly in assembly and production. In addition, can be caused by the introduction of forces in the circumferential direction rotor vibrations.

Presentation of the invention

The object of the invention is therefore to avoid the aforementioned disadvantages of the prior art. The invention is based on the technical problem of providing a rotor end which, if possible, exerts no axial forces on the rotor, thereby avoiding the occurrence of disturbing rotor vibrations caused by axial forces.

According to the invention, this object is achieved by a rotor end for rotors of thermal turbomachinery with the features of patent claim 1. An inventive mounting method is described in claim 9. Advantageous embodiments and further developments of the invention are described in the subclaims.

This avoids the disadvantages of the prior art and provides a rotor tail which does not impart axial forces to the rotor and exerts no forces in the circumferential direction on adjacent blades, so that occurrence of disturbing rotor vibrations and jamming of adjacent blades is effectively avoided.

The rotor end according to the invention is characterized in that a clamp is arranged in the residual gap, which accommodates the forces of the two end halves and two shim halves arranged between the end halves and clamped with the wedge. As a result, the forces acting in the known rotor-end constructions in the axial direction of the groove and in the circumferential direction on adjacent blades forces are effectively avoided.

The advantages of the invention are that now the clip and not as in the prior art, the rotor absorb the axial forces caused by the centrifugal force and the aufgestemmten wedge. As a result, disturbing vibrations are advantageously avoided.

An advantageous development of the invention provides that the opposing shims halves each have an undercut, in the arranged on the upper side of the wedge key flaps are hineinspreizbar. As a result, the wedge is secured in the package against flying out due to centrifugal forces.

A further advantageous embodiment of the invention provides that the supplement halves have over the undercuts Beilagelappen, which are drivable on the spread keys. This results in an additional securing of the wedge, since a drift apart of the side shells and associated exposure of the keys is safely avoided.

Furthermore, it is advantageous that the package of the two supplements and the wedge is secured by flanged halves tail. This is it also an additional fuse that intervenes in case of failure of one of the previous fuses.

It is particularly advantageous that the clamp is designed as a substantially rectangular plate with a Lägsschlitz and U-shaped cross-section. In this case, a development of the invention provides that the U-legs of the clip engage in corresponding grooves of the end halves. The staple is in axial, i. mounted in the rotor longitudinal direction in the circumferential groove. The clip is engaged with both the half shells and the half halves. Due to the centrifugal forces, the U-legs are additionally pressed into the corresponding grooves of the end halves.

Yet another advantageous development of the present invention provides that corresponding projections of the clasp halves engage in the slotted slot of the clamp. Alternatively, noses or webs may project downwardly on the shims and engage in the longitudinal slot of the clip. As a result, the force is introduced by the wedge apart driven supplements in the axial direction in the bracket. A load of Nutgrunds in the axial direction is thereby effectively avoided.

Finally, a further advantageous embodiment of the present invention provides that the clamp is made of a chromium-molybdenum alloy. As a result, the requirements for high strength with low weight of the component are advantageously met.

A method according to the invention for mounting an axially divided rotor closure, which has two end halves, two side halves, a clamp and a wedge, comprises the following steps: inserting the clamp into the circumferential groove; Mounting the two end halves, which are engaged with the clip; Assembly of the two side halves, where these are also engaged with the clip; Tension the two side halves in the axial direction by inserting the wedge. Disassembly is in reverse order. The wedges are drilled out.

An advantageous development of the method for mounting an axially divided rotor closure, further comprises the following steps: securing the wedge by Aufpreitzen the upper Keillappen in recesses of the side halves and Umbörteln of lobes of the side halves; Secure the sides of the garnish and fold over with cloths of the end halves. When disassembling the flanged cloths are usually ground away.

Brief description of the drawings

• Fig. 1 einen Schnitt in Rotorlängsrichtung durch einen erfindungsgemässen Rotor-Schluss nach Einbau in einen Verdichterrotor;
• Fig. 2 einen Schnitt in Umfangsrichtung etlang der Linie II - II aus Figur 1;
• Fig. 3 eine Seitenansicht einer erfindungsgemässen Schlusshälfte;
• Fig. 4 eine Draufsicht auf zwei Schhlusshälften;
• Fig. 5 ein Schnitt entlang der Linie V -V aus Figur 4;
• Fig. 6 eine Seitenansicht zweier erfindungsgemässer Beilagen;
• Fig. 7 eine Draufsicht auf eine erfindungsgemässe Klammer;
• Fig. 8 einen Querschnitt entlang der Linie VIII - VIII aus Figur 7; und
• Fig.9 - Fig 11 verschiedene Montagestufen des erfindungsgemässen Rotorschluss im Schnitt.

Further advantages of the invention are illustrated below together with the description of a preferred embodiment of the invention with reference to the figures. Show it:

• Fig. 1 a section in the rotor longitudinal direction by a rotor according to the invention after installation in a compressor rotor;
• Fig. 2 a section in the circumferential direction etlang the line II - II off FIG. 1 ;
• Fig. 3 a side view of an inventive end half;
• Fig. 4 a plan view of two split halves;
• Fig. 5 a section along the line V -V off FIG. 4 ;
• Fig. 6 a side view of two inserts according to the invention;
• Fig. 7 a plan view of a clip according to the invention;
• Fig. 8 a cross section along the line VIII - VIII from FIG. 7 ; and
• Fig.9 - Fig. 11 various assembly stages of the novel rotor in section.

In the figures, the same components are provided with the same reference numerals. Furthermore, only the essential elements for understanding the invention are shown.

Ways to carry out the invention

Fig. 1 shows a section in the rotor longitudinal direction by a rotor-1 according to the invention after installation in a compressor rotor. Fig. 2 shows a section in the circumferential direction along the line II - II FIG. 1 ,

The in Fig. 1 and Fig. 2 shown section represents a portion of a rotating rotor groove 3 a compressor stage. In the groove 3 all upsetting blades and spacers (not shown in this section) and the two closing blades 4, 4 are already mounted. The closing blades 4, 4 differ from the regular compression blades only in that the bulge on the inlet and outlet side is removed. In the remaining between the two closing blades 4, 4 remaining opening are three separate Assembled. The axially separated rotor closure has two end halves 9, 9, a first side half 5, a second side half 6, a bracket 8 and a wedge 7 made of chrome nickel steel. The package formed from the shims 5, 6 and the wedge 7, the clamp 8 and the end halves 9, 9 together have a comparable mass with an intermediate piece.

Fig. 3 shows a side view of an inventive closing half 9, 9 and Fig. 4 a plan view of the two half-shots. Fig. 5 shows a section along the line V -V FIG. 4 , The two end halves 9, 9 are made in the present embodiment of a chromium-nickel-molybdenum alloy. The outer contour of the closing half 9 is designed so that it corresponds to the T-shaped cross-section of the circumferential groove 3 of the rotor disk 2. In addition, in the FIGS. 3 to 5 the elongated webs or tabs 10 shown at the top of the end half 9, which are crimped at the end of assembly.

Fig. 6 shows a side view of two inventive side halves 5, 6, which are made in the present embodiment of a chromium-nickel-molybdenum alloy. The bracket 8 is the component which absorbs the axial forces in the present invention and thus provides for the relief of the rotor groove. The bracket 8 is a plan view of a substantially rectangular metal profile with a central longitudinal slot or a central elongated recess 12. The bracket 8 has a U-profile in cross-section. Through the recess 12 and the U-legs 13, the clip with the end halves 9.9 and the supplement halves 5, 6 is engaged. Together with the wedge 7 so a fastening dressing is formed.

Fig. 7 showed a detail plan view of a clip 8 according to the invention. Fig. 8 shows a cross section through the bracket 8 along the line VIII - VIII out FIG. 7 , The bracket 8 is made in the present embodiment of a chromium molybdenum alloy.

Fig.9 - Fig. 11 show different stages of assembly of the inventive rotor 1 in section.

In this case, a circumferential groove 3 is inserted with a substantially T-shaped cross-section in a rotor disk 2. In this groove 3 upsetting blades and intermediate pieces 15 are alternately mounted until the two closing blades 4 are mounted, between which no regular intermediate piece 15 can be mounted because of the small space in the residual gap.

About the residual gap two end halves 9, 9 are installed together with a bracket 8. The end halves 9, 9 are driven apart in the circumferential direction. Then two side halves 5, 6 are mounted and a wedge 7 is inserted.

As in FIG. 10 are shown, the wedges 7 in the shims recesses 18, 18, which together form a heart shape in the side view, spread. The shims 16, 16 on the heart shape then become, as in FIG. 10 shown, driven over the spread wedge 7.

The package formed from the shims 5, 6 and the wedge 7 is additionally secured by the bending over of the half-shots 10, 10. The result is the in FIG. 1 rotor-end shown.

LIST OF REFERENCE NUMBERS

1

Rotor end

2

rotor disc

3

Circumferential groove

4

final shovel

5

First supplement half

6

Second side half

7

wedge

8th

clip

9

final half

10

Final half cloth

11

Supplement lead

12

clamp recess

13

U-leg

14

Schlusshälftennut

15

connecting piece

16

side dish cloth

17

wedge cloth

18

Supplement recess

Claims (10)

1. Rotor end piece (1) for a rotor of a thermal turbomachine, having at least one circumferential slot (3) in which moving blades, intermediate pieces and two end blades (4), between which a residual gap is formed, are fitted, the rotor end piece (1) having two end piece halves (9, 9), a wedge (7), a clip (8) and two shim halves (5, 6), characterized in that the clip (8) is arranged in the residual gap and the clip (8) absorbs the forces of the two end piece halves (9, 9) and the two shim halves (5, 6) arranged between the end piece halves (9, 9) and restrained with the wedge (7).
2. Rotor end piece (1) according to Claim 1, characterized in that the opposite shim halves (5, 6) each have an undercut (18) into which wedge tabs (17) arranged on the top side of the wedge (7) can be spread.
3. Rotor end piece (1) according to Claim 2, characterized in that the shim halves (5, 6) have shim tabs (16) above the undercuts (18), and these shim tabs (16) can be driven via the spread wedge tabs (17).
4. Rotor end piece (1) according to one of Claims 1 to 3, characterized in that the pack consisting of the two shim halves (5, 6) and the wedge (7) is secured by beaded-over tabs (10) of the end piece halves.
5. Rotor end piece (1) according to one of the preceding claims, characterized in that the clip (8) is designed as an essentially rectangular plate with an aperture (12) and a U-shaped cross section.
6. Rotor end piece according to Claim 5, characterized in that the U legs (13) of the clip (8) engage in corresponding grooves (14) of the end piece halves.
7. Rotor end piece according to Claim 1, characterized in that corresponding projections (11) of the shims (5, 6) engage in the apertures (12) of the clip (8).
8. Rotor end piece according to Claim 1, characterized in that the clip (8) is made of a chrome*-molybdenum-vanadium alloy.
9. Method of fitting an axially separate rotor end piece which has two end piece halves, two shim halves, a clip and a wedge, the method comprising the following steps:

   - inserting the clip into the circumferential slot;

   - fitting the two end piece halves, said end piece halves being brought into engagement with the clip;

   - fitting the two shim halves, said shim halves likewise being brought into engagement with the clip;

   - restraining the two shim halves in the axial direction by inserting the wedge.
10. Method of fitting an axially separate rotor end piece according to Claim 9, the method also comprising the following steps:

    - securing the wedge by spreading out the top wedge tabs into recesses of the shim halves and by beading over tabs of the shim halves;

    - securing the shim halves and beading over tabs of the end piece halves.

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