EP3511524A1 - Rotor with sealing elements fixed in blade retention grooves - Google Patents

Abstract

The invention relates to a rotor for a gas turbine having a rotor disk (01), which (01) distributed in the circumference has a plurality of blade retaining grooves (02) extending axially through the rotor disk (01). In the blade holding grooves (02) each rotor blades (11) are fixed with a blade root (12). Furthermore, the rotor has a plurality of sealing elements (21) arranged distributed in the periphery in front of the end face of the rotor disk (01), which (21) cover the blade retaining grooves (02) in sections. A particularly advantageous load transfer is provided by the attachment of the sealing elements (21), each with one in the blade retaining grooves (02) recorded holding foot (22).

Description

The invention relates to a rotor for use in a gas turbine with a particularly advantageous attachment of a sealing element for covering Schaufelhaltenuten in a rotor disk.

Arrangements for frontal covering of blade retaining grooves in rotor disks are well known in the prior art. For example, this shows the execution EP 3090135 a rotor disk, which has a plurality of circumferentially spaced blade holding grooves, in each of which a blade is attached to the blade root. In order to cover the blade holding grooves, in particular for separating a cooling air flow leading to the rotor blades from the hot gas flowing through the gas turbine, a plurality of sealing sheets arranged distributed around the circumference are provided in front of an end face of the rotor disk in the area of the blade holding grooves. These are axially mounted in this case with an inner edge portion in a circumferential annular groove in the rotor disk. The rotor blades each have a blade platform projecting beyond the end face of the rotor disk. In each of these ring segment grooves are present on the side facing the rotor axis, in which the sealing plates are fixed with an outer edge portion both axially and radially. Thus, a simple and reliable storage of the sealing plates on the rotor disk is made possible. A disadvantage of this embodiment, however, is that the radial support via the blades takes place.

An improved embodiment of a rotor for a gas turbine discloses the EP 3129600 , Once again, the rotor has a rotor disk, on which a plurality of moving blades are distributed in each case in each blade holding groove. On the front side, blade holding grooves are covered analogously by means of sealing plates. Unlike the previous solution However, here provided that the Ringsegmentnut is designed as a T-groove and the sealing plates each have at the inner edge portion on the side facing the rotor axis a bilateral axial elevation. By this shaping is achieved that the radial fixing of the sealing plates is no longer on the blades, but now in the annular groove of the rotor disk and thus the centrifugal forces are introduced directly into the rotor disk.

However, the above-described embodiment causes the problem that the annular groove must be interrupted to allow the mounting of the sealing plates. This in turn leads to the problem that the holder of the sealing plate is weakened at the position of the interruption.

Object of the present invention is therefore to enable an improved and uniform radial support of the sealing plates on the rotor disk.

The stated object is achieved by an embodiment according to the invention according to the teaching of claim 1. Advantageous embodiments are the subject of the dependent claims.

The generic rotor is used in particular for use in a gas turbine. However, the generic embodiment can also be used in other turbomachines, such as a steam turbine. At least the rotor comprises at least one rotor disk which has a plurality of blade retaining grooves distributed around the circumference. In this case, the blade retaining grooves extend axially through the rotor disk. The exact alignment of the blade retaining grooves and whether they are linear or arcuate, is irrelevant in this respect. At least it is further provided that distributed on the rotor circumference a plurality of blades are arranged. These each have a blade root, an adjoining blade platform and a radially extending blade leaf extending therefrom. The Blades are attached to the blade root in the blade retaining grooves. The blade platform extends in the axial direction and in the circumferential direction, wherein at least on one side of the blade platform extends beyond an end face of the rotor disc out.

Furthermore, the generic rotor comprises a plurality of sealing elements, which are arranged distributed in the circumference in front of the end face of the rotor disk and in this case cover the blade retaining grooves in sections. It is provided that the sealing elements are mounted in the axial direction of the blade, wherein this can be done on the one hand on the blade root and / or on the other hand on the blade platform.

In order to improve the radial support of the sealing elements on the rotor disk, it is now provided according to the invention that the sealing elements are each provided with a retaining foot arranged pointing in the direction of the rotor axis. In this case, the retaining foot is designed to be complementary to the lower part of the blade retaining groove and arranged in this, so that a bearing of the sealing element takes place with the retaining foot in the radial direction and in the circumferential direction in the blade retaining groove of the rotor disk. This means that the sealing element is arranged on the one hand with the holding foot in the blade holding groove and with the part radially outside of the holding foot in front of the blade holding groove and thus covers the blade holding groove in the radially upper region.

By means of the embodiment according to the invention, a particularly advantageous fastening of the sealing elements to the rotor disk becomes possible without the necessity of positioning a last sealing element on a mounting gap. Thus, a vulnerability by the novel embodiment is avoided.

With the inventive arrangement of the sealing element on the one hand in front of the end face of the rotor disk or in front of the blade retaining grooves and on the other hand with the arrangement of the retaining foot connected in the blade retaining groove is a particularly advantageous design of the rotor disk to the effect that the rotor disk in the lower pointing to the rotor axis portion of the blade retaining groove has an extension in the form of a shoulder which extends axially in front of the end face. In this case, the lower part of the blade holding groove, in which the holding foot of the sealing element is arranged, extends into the extension. Thus, advantageously, the sealing element can be made without an otherwise necessary offset, wherein an arrangement in the blade retaining groove and at the same time an arrangement in front of the blade retaining groove takes place.

It is particularly advantageous if the sealing elements are fixed axially to the rotor blades at least on one side in the edge region pointing radially outward. For this purpose, it can be provided in one embodiment that the sealing elements abut with an outer edge portion on a corresponding shoulder of the blade platform.

In a particularly preferred embodiment, the blade platform of the rotor blades in the overhang extending beyond the end face of the rotor disk has a ring segment groove extending in the circumferential direction and opening toward the rotor axis. Here, the sealing elements are mounted with the respective radially outwardly facing outer edge portion in at least one Ringsegmentnut, so that the sealing elements are fixed in the axial direction of the blade.

In addition or as an alternative to the axial fixing of the sealing elements on the blade platform, it can be advantageously provided that the blade root has an attachment means which is undercut in the axial direction. In contrast, a complementary axially undercut retaining means is arranged on the holding element. By the engagement of the holding means on the fastening means, the axial fixation of the sealing element on the blade root of the blade is effected.

How the fastening means and the retaining means is carried out, this is initially irrelevant, so far may act to interlocking hooks. Likewise, it is conceivable to design the fastening means or the retaining means as an axially opening T-slot or the like and to make the retaining means or the fastening means in the form of a T-shaped slot.

An axial positioning of the rotor blades on the rotor disk which acts at least on one side can be effected by means of the sealing elements. For this purpose, it is particularly advantageously provided that the sealing elements in the outer quarter of the blade retaining grooves or in the radial position of the connection of the fastening means with the retaining means in each case abut axially between two blade retaining grooves on the rotor disk. With the axial fixation of the sealing elements on the blades and the axial contact of the sealing elements on the rotor disk is achieved that also the blades are fixed axially in one direction on the rotor disk. It is particularly advantageous if the installation of the sealing elements on the rotor disk, in particular in the case of axial fixing of the sealing elements on the blade platform, takes place as close as possible to the outer circumference of the rotor disk.

The system of sealing elements on the rotor disk can be done directly by their own flat contact on the front side of the rotor disk. However, it is advantageous if either the rotor disk has an abutment shoulder extending axially between in each case two blade retaining grooves and / or the sealing element has an abutment shoulder extending to the rotor disk. Thus, an advantageous direct axial support of the blade can be ensured via the sealing element on the rotor disk.

A further particularly advantageous securing of the sealing elements and of the rotor blades is achieved if, in addition, a securing element is used which causes an axial fixation of the sealing elements on the rotor disk. If available axial engagement of the sealing elements on the rotor disk causes insofar the securing element an axial fixation in the opposite direction.

The advantageous axial fixation can be carried out in different ways, wherein in a particularly advantageous embodiment, in each case between two blade retaining grooves a securing receptacle in the rotor disk is present. In this, the securing element is arranged and extends in the circumferential direction over the retaining foot of the sealing element and thus causes the axial fixation of the sealing element and thus at the same time the blade. In this case, in a particularly advantageous manner, the securing receptacle is formed by an axially opening T-slot.

The securing element is advantageously a section of a securing ring and is in this case formed by a sheet metal section.
Furthermore, it is advantageous if viewed in the circumferential direction, the securing element has successive narrow and wide areas viewed in the radial direction. This allows a bayonet-like attachment of the fuse element in the securing receptacles of the rotor disk. For mounting, the wider area can thus first be positioned in the area of the blade retaining grooves and the narrower area can be inserted into the T-slots. By displacement in the circumferential direction, the axial fixation is achieved.

The securing of the securing elements, in turn, to prevent a displacement in the circumferential direction can be done in various ways. On the one hand, it is possible to provide on the securing element a locking tab, which causes by bending and thereby resulting abutment of the locking tab in the circumferential direction of the rotor disk or the blade, whereby a displacement of the securing element in the circumferential direction is prevented.

Furthermore, a backup of the fuse elements can be done by a locking pin is used, which is fixed in the axial and / or radial direction of the rotor disk and adjacent to the securing element secures this against displacement in the circumferential direction.

In a further embodiment, a separate locking tab is used, which is attached adjacent to the securing element, or between two securing elements on the rotor disk.

Instead of using a circumferentially extending securing element, it is alternatively possible to provide a securing element between the groove bottom of the blade retaining groove and the retaining foot of the sealing element. For this purpose, the securing element can be axially fixed at one end to the rotor disk and cause axial insertion after insertion of blades and sealing element into the blade retaining groove by bending the axially opposite end of the securing element.

If an improved sealing of the blade holding groove is also necessary in the region of the holding foot, then in a further embodiment it is possible to provide a sealing groove which opens radially outwardly between the two blade holding grooves in the rotor disk. In each case, a sealing strip is inserted, which bears against the sealing element at least during rotation of the rotor and thus favors a seal.

The radially outer region of the blade retaining grooves or the end face of the rotor disk is covered by the sealing element. However, due to the attachment of the retaining foot of the sealing element in the blade retaining groove there is no cover of the rotor disk or the blade retaining groove (although this would be possible by a cover plate in front of the retaining foot on the sealing element). Therefore, it is particularly advantageous for the separation of the gas turbine flowing through the hot gas, when a sealing portion is arranged on the sealing element, which extends axially opposite to the end face of the rotor disk and in the circumferential direction. Particularly advantageously, the sealing portion on the radially outwardly facing side extending in the circumferential direction, axially-radially aligned sealing ribs. Thus, the sealing portion can effect an advantageous sealing cooperatively with another component, for example a stator ring.

Fig. 1

ein erstes Ausführungsbeispiel für einen Rotor mit den in Schaufelhaltenuten befestigten Dichtelementen;

Fig. 2

das Ausführung aus Fig. 1 im perspektivischen Schnitt;

Fig. 3

die Rotorscheibe zur Ausführung aus Fig. 1;

Fig. 4

die Laufschaufel mit Dichtelement zur Ausführung aus Fig. 1;

Fig. 5

das Dichtelement zur Ausführung aus Fig. 1;

Fig. 6

ein Schnitt durch den Rotor im Bereich des Dichtelements;

Fig. 7

die Darstellung aus Fig. 2 im Bereich des Haltefußes;

Fig. 8

das Sicherungselement zur Ausführung aus Fig. 1;

Fig. 9

eine weitere Detailansicht im Bereich des Haltefußes;

Fig. 10-12

Beispiele zur Ausführung von Arretierungsbolzen und Arretierungslasche;

Fig. 13

ein zweites Ausführungsbeispiel eines erfindungsgemäßen Rotors;

Fig. 14

eine Schnittansicht im Bereich des Haltefußes zur Ausführung aus Fig. 13;

Fig. 15

das Dichtelement zur Ausführung aus Fig. 13.

In the following figures, exemplary embodiments of a rotor according to the invention are outlined. Show it:

Fig. 1

a first embodiment of a rotor with the attached in Schaufelhaltenuten sealing elements;

Fig. 2

the execution Fig. 1 in perspective section;

Fig. 3

the rotor disk for execution Fig. 1 ;

Fig. 4

the blade with sealing element for execution Fig. 1 ;

Fig. 5

the sealing element for execution Fig. 1 ;

Fig. 6

a section through the rotor in the region of the sealing element;

Fig. 7

the presentation Fig. 2 in the area of the holding foot;

Fig. 8

the fuse element for execution Fig. 1 ;

Fig. 9

a further detail view in the area of the holding foot;

Fig. 10-12

Examples of the execution of locking pin and locking tab;

Fig. 13

a second embodiment of a rotor according to the invention;

Fig. 14

a sectional view in the region of the holding foot for execution Fig. 13 ;

Fig. 15

the sealing element for execution Fig. 13 ,

In the FIGS. 1 to 13 a first embodiment of a rotor according to the invention is shown. It can be seen in the Fig. 1 In the blade holding grooves 02 are fixed circumferentially distributed blades 11. In front of a front side of the rotor disk 01 circumferentially distributed sealing elements 21 are fixed, which are 21 axially secured by a securing element 31 ,

This shows the Fig. 2 the execution Fig. 1 in a perspective sectional view. In turn, the rotor 01 with the blade retaining grooves 02, in which 02 the rotor blades 11 are fastened, can be seen. The sealing elements 21 hereby partially cover the blade retaining grooves 02 in the radially outer region and in this case extend as far as the rotor blades 11. In the radially lower region on the side facing the rotor axis, the sealing elements 21 are fastened in the blade retaining grooves 02.

In the Fig. 3 now the rotor disk 01 is shown. The blade holding grooves 02, which extend axially through the rotor disk 01, can be seen. In the radially lower region of the blade retaining groove 02, the rotor disk 01 has an extension 03 in the form of a shoulder, so that the blade retaining grooves 02 extend axially in the region of the extension 03 over the overlying end face of the rotor disk 01. At the extension 03 of the rotor disk 02 each fuse receptacles 08 are arranged between the blade retaining grooves 02, which 08 in this case in the form of a are designed axially opening T-slot. Furthermore, the rotor disk 01 in the region of the extension 03 on a circumferentially extending and radially outwardly opening sealing groove 09. On the outer circumference of the rotor disk 01, in each case between two blade retaining grooves 02, an abutment shoulder 07 extending axially beyond the end face is located.

In the Fig. 4 the blade 11 is shown pre-assembled with the sealing element 21. Evident is the structure of the blade 11 with the blade root 12, which 12 has a complementary to Schaufelhaltenut 02 shape. At the blade root 12, a blade platform 13 connects, which 13 extends in the circumferential direction and axially. In the overhang of the blade platform 13, which extends beyond the end face of the rotor disk, there is a ring segment groove 16 which extends in the circumferential direction and opens radially to the rotor axis.

In front of an end face of the blade root 12 extending in the circumferential direction beyond the blade root 12, the sealing element 21 is located. This 21 is axially mounted with an outer edge portion 26 in the Ringsegmentnut 16.

In the Fig. 5 the sealing element 21 is shown in a perspective view. Evident is its flat, circumferentially and radially extending shape with the outer edge portion 26. On the side facing the rotor axis, the sealing element 21 has a retaining foot 22. This 22 is in this case designed to be complementary to blade holding groove 02. Furthermore, the sealing element 21 has a sealing portion 24, which extends axially from the flat basic shape of the sealing element 21, starting axially and in the circumferential direction opposite to the blade. The sealing portion 24 in this case has circumferentially extending axially-radially aligned sealing ribs.

In the Fig. 6 the rotor is shown in section in the region of the sealing element 21. The rotor disk 01 and the blade platform 13 of the rotor blade 11 can be seen again. The sealing element 21, which is mounted with the outer edge portion 26 in the annular segment groove 16 of the rotor blade 11, is located in front of the end face of the rotor disk 01. For the axial support of the sealing element 21 on the rotor disk 01, the rotor disk 01 on a contact shoulder 07, which 07 extends axially in front of the end face of the rotor disk 01 and comes to rest on the sealing element 21.

Furthermore, to recognize the sealing portion 24 with the sealing ribs. Below the sealing element 21 is located in an extension 03 of the rotor disk 01, the sealing groove 09. It can also be seen in the rotor disk 01, the T-slot as a fuse holder 08 for receiving a fuse element 31st

In the Fig. 7 is again shown in an enlarged view analogous to Figure 2, the region of the holding foot 22. The rotor disk 01 with the extension 03 and the blade retaining groove 02 can be seen in turn. The sealing element 21 is fastened here with the retaining foot 22 in the blade retaining groove 02. A further axial fixation of the sealing element 21 and thus at the same time the blade 11 is achieved by a securing element 31 is attached to the rotor disk 01, which 31 prevents axial movement of the sealing element 21 in the region of the holding foot 22.

This shows the Fig. 8 the securing element 31 in the form of a circumferentially extending sheet metal section with radially wider and narrower sections seen. This allows a bayonet-like attachment of the fuse element 31 to the rotor disk 01st

In the Fig. 9 again, the area of the holding foot 22 is shown enlarged. To recognize is again the rotor disk 01 with the extension 03 as well as the in the blade holding groove 02 fixed blade 11, which has a further 11 extending in the axial direction of the investment projection 17 in contact with the back of the sealing element 21. Furthermore, it can be seen how the retaining foot 22 is fixed in the axial direction by means of the securing element 31. An improved seal between the sealing element 21 and the radially outwardly facing top of the extension 03 is achieved by the arrangement of a sealing strip 36 in the sealing groove 09.

To secure the securing element 31 against displacement in the circumferential direction are various options available, in an exemplary embodiment, a locking pin 32 - shown on the right side of Fig. 10 - Is used, which is attached to the rotor disk 01 between two securing elements 31.

A securing of the locking bolt 32 can in turn be done by means of a fixed to the rotor disk 01 locking tab 34. Alternatively, it would also be possible, the locking pin 32 by means of another pin, as in Fig. 11 shown to secure.

Likewise, it would also be possible, a locking tab 33 directly on the rotor disk 01 in each case between two securing elements 31, as in Fig. 12 shown to install.

In the Fig. 13 Now another embodiment is outlined. In turn, a rotor disk 61 with the sealing elements 81 fastened in blade holding grooves 62 can be seen. The rotor disk 61 analogously has an extension 63 extending axially in front of an end face for the corresponding widening of the blade retaining grooves 62 in the radially lower region. Likewise, an abutment paragraph 67 for the axial support of the sealing elements 81 is present. An advantageous sealing portion 84 with extending in the circumferential direction Sealing ribs is arranged directly radially outside of the holding foot 82 in this embodiment.

Not shown, but provided in accordance with the previous embodiment, the fixing of an outer edge portion 86 of the sealing elements 81 in a corresponding Ringsegmentnut the respective blades in the axial direction.

A further difference from the previous embodiment is that the securing takes place in the axial direction by means of a securing element 91 arranged in the blade retaining groove 62 in the form of a sheet metal tab - see Fig. 14 , Here, it is provided that the securing element 91 is arranged between the holding foot 82 and the groove bottom of the blade retaining groove 62 and in this case is fixed axially on the side facing the rotor disk by means of a bend on the rotor disk 61. Opposite, a bend of the securing element 91 is also provided axially in front of the retaining foot 82.

Furthermore, it can be seen the formation of a ring cavity 64 between the end face of the rotor disk 61 and the extension 63, so that a better distribution of cooling air is possible. For this purpose, the rotor disk further on the extension 63 penetrating cooling air holes 10.

In the Fig. 15 is again the sealing element 81 to the embodiment of Fig. 13 shown. In turn, it can be seen its flat, in the circumferential direction and radially extending basic shape with extending in the axial direction and in the circumferential direction sealing portion 84 and the retaining base 82nd

Claims (11)

Rotor, in particular for a gas turbine, with at least one rotor disk (01,61), which (01,61) distributed in the circumference a plurality of axially through the rotor disk (01,61) extending blade holding grooves (02,62), and with a A plurality of rotor blades (11), which (11) in each case with a blade root (12) in a Schaufelhaltenut (02,62) are fixed and adjoining the blade root (12) extending over an end face of the rotor disk blade platform (13) and a have radially outwardly extending airfoil (14), and with a plurality in front of the end face of the rotor disk (01,61) distributed circumferentially arranged sealing elements (21,81), which (21,81) the blade retaining grooves (02,62) sections cover and are axially fixed to the blade root (12) and / or the blade platform (13),
characterized,
that the sealing elements (21,81) having a retaining foot (22,82) in the Schaufelhaltenut (02,62) are radially fixed. Rotor according to claim 1
characterized,
that the sealing elements (21,81) with an outer edge portion (26,86) abut the blade platform (13); and or
in that (16) the sealing element (21, 81) is axially mounted with an outer edge section (26, 86). Rotor according to claim 1 or 2,
characterized,
in that the blade root (12) has an axially undercut fastening means and the sealing element (21, 81) has a complementary axially undercut retaining means, which effect the axial fixation. Rotor according to one of claims 1 to 3,
characterized,
that the sealing elements (21,81) lie in the radially outer quarter of the height of the Schaufelhaltenuten (02,62) on the rotor disk (01,61). Rotor according to one of claims 1 to 4,
marked by
at least one securing element (31, 91), which (31, 91) effects an axial fixation of the sealing elements (21, 81) on the rotor disk (01, 61). Rotor according to claim 5,
characterized,
in that the rotor disk (01, 61) has at least one circumferentially extending securing receptacle (08) between two blade retaining grooves (02, 62), in which (08) the securing element (31, 91) is accommodated, wherein in particular the securing receptacle (08 ) is formed by an axially opening T-slot. Rotor according to claim 5 or 6,
characterized,
that the securing element (31) is a portion of a retaining ring and is formed by a sheet metal section; and or
that the securing element (31) successively comprises the narrow areas and broad areas in the circumferential direction and like a bayonet on the fuse receptacle (08) can be mounted. Rotor according to one of claims 5 to 7,
characterized,
that a locking pin (32) in the axial and / or radial direction in the rotor disk (01,61) and in the securing element (31) or adjacent to the securing element (31) engages and prevents displacement of the securing element (31) in the circumferential direction; and or
that a deformable locking tab (32) on the securing element (31) or adjacent to the securing element (31) on a shoulder on the rotor disk (01,61) and / or the sealing element (21,81) engages and a displacement of the securing element (31) in Circumferential direction prevented. Rotor according to claim 5,
characterized,
that the securing element (91) between the groove base of the Schaufelhaltenut (02) and the sealing element (21,81) and having a first end to the rotor disc (01,61) and with the second axial end of the sealing element (21,81) axially abutting. Rotor according to one of claims 1 to 9,
characterized,
in that a sealing groove (09) which opens radially outwards to the sealing element (21, 81) is arranged in the rotor disk (01, 61) between the blade retaining grooves (02), in which (09) a sealing strip (36) is arranged. Rotor according to one of claims 1 to 10,
characterized,
in that on the side facing away from the rotor disk (01, 61) there is arranged on the sealing element a sealing section which has circumferentially extending axially-radially aligned sealing ribs.

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