EP1183444B1 - Turbomachine and sealing element for a rotor thereof - Google Patents

Abstract

The invention relates to a turbomachine (1) with a rotor (25) that extends along a rotational axis (15). Said rotor (25) has a rotor shaft groove (31) with a groove base (33) and a rotor blade (13) with a blade footing (35). Said blade footing (35) is introduced into the rotor shaft groove (31) and a gap (37) is formed between the blade footing (35) and the groove base (33). A sealing element (39) is provided for sealing said gap (37). Said sealing element is at least partially accommodated by the blade footing (35) and is mobile in relation to the same. The invention also relates to a sealing element (39), especially for a rotor (25) of a turbomachine (1), comprising a first partial sealing element (53A) and a second partial sealing element (53B). The inventive sealing element (39) performs its sealing action under the influence of an external force, especially the centrifugal force.

Description

The invention relates to a turbomachine with a along a rotation axis extending rotor, wherein the Rotor has a rotor shaft groove, and a blade with a blade root inserted into the rotor shaft groove is, and a gap between the blade root and the rotor shaft groove is formed. The invention further relates to a Sealing element for a rotor of a turbomachine.

Rotatable blades of turbomachinery, for example of gas or steam turbines or compressors, are in different embodiments over the full extent the peripheral surface of a rotor shaft, e.g. a rotatable one Running disk has attached. A blade points usually an airfoil, a paddle platform and a blade root with a mounting structure, which of a correspondingly complementarily configured rotor shaft groove is added to fix the blade. The rotor shaft groove can act as a circumferential groove or axial groove be made of the peripheral surface of the rotor shaft. The rotor shaft groove has a groove base. Structurally conditioned is after inserting the blade root of a blade in the rotor shaft groove through each adjacent Rotor components formed a gap. The gap gives in operation cause the rotor to leakages of coolant or an action fluid driving the rotor through the gap therethrough. Such a gap is formed between the blade root and the groove base. A split of this kind can also between two adjoining paddles from circumferentially adjacent blades and between the peripheral surface of the rotor shaft and a radially to the peripheral surface adjacent paddle platform occur. To the possible leakage flows through the gap, such as the escape of coolant, e.g. of cooling air in the flow channel A gas turbine, to limit, becomes intense after effective Wanted sealing concepts. These must be resistant to the occurring temperatures and the mechanical load due to the considerable centrifugal forces on the rotating system.

From DE 198 10 567 A1 is a sealing plate for a Blade of a gas turbine out. If cooling air, which is the Moving blade is supplied, escapes into the flow channel, This leads inter alia to a reduction in the efficiency the gas turbine. The sealing plate, which in one Gap between the blade platforms of two adjacent Rotor blades is used, the leakage currents due prevent the escape of cooling air. An additional Sealing effect is achieved by sealing pins, which also between the blade platforms of two adjacent ones Blades are installed. It is a variety of sealing pins required to achieve the desired sealing effect the escape of cooling air from the adjacent blade platforms to reach.

In US Patent 4,021,138 is a sealing concept for a rotor of a gas turbine with a running disk and with an internally cooled blade described. The running disk has an end face and one along the axis of rotation the front surface opposite back surface, as well an axial pulley groove extending from the end face extends into the back surface. The blade has a Shovel foot taken up by the axial pulley groove is. In the running disk radially inwardly adjacent to the Blade foot on a coolant chamber, which is the running disk in axial direction completely from the end face to the Rear surface penetrates. In the blade are coolant channels provided, from the blade root to the blade extending in the radial direction and in fluid communication stand with the coolant chamber, so that for internal cooling the blade a coolant from the coolant chamber enters the coolant channels. This is done via a the front face axially upstream coolant supply the coolant chamber subjected to a coolant. To the coolant chamber seal against leakage of coolant, is a first seal plate on the face and a second seal plate disposed on the rear surface of the rotor disk. For improved sealing has the end face facing side of the first sealing plate is in Circumferential direction of the rotor disk extending channel, the opens towards the face. In the radial direction is the Channel bounded by a radially outwardly disposed outer Edge region and from one, the outer edge region opposite, radially inwardly disposed inner edge region, wherein the outer and the inner edge region of the Adjacent end face. The outer edge area is designed that thereby the adjacent to the end face part of the channel in a direction opposite to the face normal inclined, this direction being a component radially outward. Into the channel is a Sealing rod, which extends along the circumferential direction, movably introduced. Moved during operation of the rotor the sealing rod in the channel under centrifugal force along the outer edge region radially outward and in Direction against the frontal area, where he finally his Gasket position occupies. In the sealing position is the sealing rod in contact with the face and seals one Split off, between the face and the face facing side of the sealing plate is formed. On This way should largely be prevented that coolant from the coolant chamber or the coolant supply through the Gap exits. By using the relatively extended Sealing plates and the additional sealing bars is this solution is very expensive. Furthermore, maintenance and Repairs to the blade only after complete Removal of these sealing components from the rotor possible.

EP 0 799 974 A2 discloses a sealing element for a moving blade a turbomachine. The turbomachine points in this case a rotor, with a radially inwardly arranged Rotor disc, wherein radially outward on the rotor disc a plurality of blades in the circumferential direction of the rotor disk attached to form a respective gap. Cooling channels are provided for cooling the rotor through the rotor disc and the blades in radial Extend direction. To get a leak on coolant (Leakage) in the area of blade attachment from the gap to limit is between the blade root and the rotor disk arranged a sealing element. The sealing element leads under Centrifugal force from a tilting movement and reaches thereby its sealing position. To the sealing element in the direction the axis of rotation before falling out of the gap secure, the sealing element has two securing teeth, the a radially inwardly formed projection in the blade root encompass, wherein the sealing element, in particular one of Fuse teeth, at least partially the front side of the rotor disk sticking out of the gap.

The invention is based on the object, a turbomachine with a rotor having a rotor shaft groove and a groove base and a blade with a Blade foot, wherein the blade root used in the Rotorwellennut is to specify with a sealing element. The sealing element in particular, an efficient limitation of axial Allow leakage currents, and against the occurring mechanical and thermal loads as resistant as possible be. Another object of the invention is to provide a sealing element, in particular for a rotor of a turbomachine, specify.

According to the first object is achieved by a Turbomachine with one moving along a rotation axis extending rotor having a rotor shaft groove with a Nutgrundfläche and a blade with a Blade foot, wherein the blade root used in the Rotorwellennut is and between the blade root and the Nutgrundfläche a gap is formed, wherein a sealing element for sealing the gap is provided, which at least partially is received by the blade root, wherein the sealing element is movable relative to the blade root, and wherein the Sealing element under centrifugal force in contact with the Groove base is and thereby seals the gap.

The invention is based on the consideration that during operation of a Turbomachine, for example, a gas or steam turbine or a compressor, the rotor one along this flowing action fluid, e.g. a hot gas, steam or heated Air, is exposed. An action fluid can thereby do an expansion work on the blades and rotate them around the axis of rotation. Of the the blade having rotor is both thermal and also mechanically, in particular due to the rotation occurring centrifugal forces, very heavily loaded. For cooling the rotor and especially the blade becomes a coolant, e.g. Cooling air, usually used by suitable coolant supply is supplied to the rotor. there Both leakage currents to coolant and to flowing action fluid - so-called gap losses - in the formed by the blade root and the Nutgrundfläche gap occur. These leakage currents are very disadvantageous on the cooling efficiency as well as the mechanical installation resistance (Smoothness and creep strength) of the blade in the Rotor shaft groove off.

With the invention, a new possibility is shown, the Gap effectively seal against possible leakage currents. This is achieved, on the one hand, in that the sealing element at least partially absorbed by the blade root and is movable in relation to this. On the other hand, the im Operation of the turbomachine, i. during rotation of the rotor, occurring centrifugal force targeted for sealing purposes exploited. The blade root thus serves in addition to the attachment of the Blade at the same time receiving the sealing element. Furthermore, by the specified embodiment, the sealing element guided in the blade root. The gap extends in radial and axial direction and in the circumferential direction of the Rotor, the axial extent of the gap usually is dominant, as well as the expansion of the gap in the circumferential direction is greater than the radial dimension. The exact Geometry of the gap is of the specific design the rotor shaft groove and the groove base, as well as the blade root certainly. The sealing element can individually the particular geometry of the rotor and the requirements adapted to the leakage currents to be limited become.

According to the invention, the sealing element seals the gap below Centrifugal force. During operation of the turbomachine the sealing element is then due to the rotation through the radially outwardly directed centrifugal force in its sealing position brought and unfolds its sealing effect. The sealing element is pressed firmly against the groove base and seals the gap.

An essential advantage over conventional sealing concepts results from the targeted sealing of the gap. This makes it possible to realize a very compact design. Extensive sealing elements, which are very costly are, thus unnecessary. The sealing element will be there locally arranged where it is needed to efficiently limit leakage currents is required. During operation of the rotor, this achieves Sealing element while its sealing position and unfolds his Sealing effect. In this case, the sealing element comes in contact with the groove base and is pressed firmly against the groove base. The fact that the sealing element furthermore at least partially received by the blade root is the gap sealed. In this way, for example, the entrance from an action fluid, e.g. the hot gas in a gas turbine, effectively prevented in the gap. This protects the Material of the rotor, in particular the material of the blade root, before the high temperatures and the possible oxidizing and corrosive influences of the action fluid. By the inhibition of leakage flows of action fluid and / or of coolant in the gap through the sealing element, become temperature gradients avoided in the blade attachment. Possible thermal stresses resulting from a disabled thermal expansion of adjacent rotor components at temperature differences result will be reduced. Of the Blade foot of a blade and the Rotorwellennut the Rotor blade receives and fixes, can therefore with a significantly lower tolerance can be produced. A lesser one Tolerance has an advantageous effect on the mechanical Installation resistance of the blade and the smoothness of the rotor out.

In particular, fits that are used to attach the blade root are provided in the rotor shaft groove, with a smaller Game be provided. This also reduces accordingly the possible leakage currents through the fit. Since that Sealing element at least partially received by the blade root is, on the one hand, it is safe and against one Falling out of the rotor secured, on the other hand it is present protected from immediate action by the action fluid. In this case, the sealing element is not necessarily firmly to a blade, in particular to the blade root coupled. This facilitates assembly or repair work on a blade, e.g. exchanging a Blade, without much effort. The sealing element remains of it largely untouched and can therefore also be used several times become.

According to the invention, the sealing element has a first Part sealing element and a second partial sealing element, which are movable relative to each other. The partial sealing elements can be designed so that they in particular Do a partial sealing function for different ones areas to be sealed in the gap, in particular for Different areas of Nutgrundfläche, take over. The Part sealing elements then complement each other by their pairs Arrangement for a sealing element, wherein the sealing effect of Paired system of partial sealing elements is larger than the a single partial sealing element. By a particularly adapted design of the partial sealing elements to each To be sealed areas in the gap succeeds that the Sealing effect of the paired arrangement is greater than it approximately would be feasible with a one-piece sealing element. By the relative mobility of the partial sealing elements is thus a particularly flexible and efficient system Part sealing elements provided. Here are both relative Translations as well as rotations of the partial sealing elements intended against each other. If the partial sealing elements themselves for example, in a plane perpendicular to the axis of rotation extend, the relative movements are substantially in limited to this level. The relative mobility of the Part sealing elements allows a very adapted system, which depends on the thermal and / or mechanical Load of the rotor and the specific geometry of the sealed Spalten is designed. The adapted system Part sealing elements is designed and stored in this way, that under the action of external forces, e.g. of the Centrifugal force and the normal and bearing forces (reaction forces), adjusted to a certain extent, and thereby his Unfolding sealing effect. Advantageously, furthermore possible thermally or mechanically induced voltages through the movable pair of partial sealing elements clearly better balanced than conventional sealing concepts.

Preferably, the rotor has a running disk, which the Rotor shaft groove with the groove base comprises, wherein the Ro Torwellennut extends along a transverse axis, opposite a plane perpendicular to the axis of rotation is inclined. The attachment of the rotatable blade in the rotor shaft groove is thus made so that they are in the operation of the rotor the blade stresses due to flow and centrifugal forces as well as blade vibrations with high safety absorb and the forces occurring on the rotor and finally can transfer the entire rotor. The attachment the blade can, for example, by axial grooves with a blade in a specially designed, extending substantially in the axial direction Disk groove is clamped. For low loads, e.g. in axial compressor blades in compressors, are simple fastenings of the blade, for example with a swallowtail or lava foot, possible. For Steam turbine power amplifiers with long blades and accordingly large blade centrifugal forces comes in addition to the so-called Plug foot and the axial Tannenbaumfuß in question. The axial Fir-tree fastening is also preferably used in thermally highly loaded blades in gas turbines. In this case, the rotor shaft groove along the transverse axis extend completely over the entire disk. Of the Gap between the groove base and the blade root is then radially open and extends along accordingly the transverse axis.

Preferably, the sealing element is in a recess, in particular in a groove, arranged in the blade root. A fallback of the sealing element and / or a fuse against Throwing out of the sealing element with centrifugal force in stationary operation or with a transient load of the rotor is achieved in that the sealing element in a suitable recess is arranged in the blade root. Through the recess is also in the blade root a Reaction surface prepared, which expediently as a partial surface the recess is formed. In the case of a groove this reaction surface produced for example on the groove base. The reaction surface is then radially outward in the Shovel arranged and lies the groove base of the rotor shaft groove along the radial direction.

To achieve the best possible sealing effect during surgery of the sealing element in the recess, is the reaction surface with correspondingly low and well-defined surface roughness produced. After the actual production the recess, in particular the groove, for example by Material removal of the blade root by means of a milling or Turning process, can on the groove bottom by polishing a reaction surface be created with the desired roughness.

The blade root preferably has a first blade root edge and one along the axis of rotation of the first blade root edge opposite second Schaufelfußrand on, as well a blade root center region extending axially between the first Schaufelfußrand and the second Schaufelfußrand arranged is, wherein a sealing element in the region of the first Schaufelfußrand and / or the second blade root edge and / or the Schaufelfußmittenbereich is arranged. Regarding the flow direction a flowing action fluid, for example a hot gas of a gas turbine, this is e.g. the first Blade root edge upstream and the second blade root edge arranged downstream. Depending on the design conditions and requirements with regard to the sealing effect to be achieved in the gap, allows this geometric breakdown an embodiment and arrangement of the sealing element or more Sealing elements in different sections of the blade root.

The arrangement of a sealing element in the region of the first, upstream Schaufelfußrands limited in the first Line the entry of pouring, possibly very hot, action fluid into the gap, thus preventing one Damage to the rotor. The arrangement of the sealing element in Area of the second, downstream Schaufelfußrands serves primarily to prevent the escape of coolant, e.g. under a certain pressure cooling air in the gap, in the axial direction upstream along the groove base to limit in the flow channel. Since the action fluid relaxed in the flow direction, the pressure of the action fluid continuously degraded in the flow direction. An under a certain pressure refrigerant in the gap is therefore in the direction of the lower ambient pressure from the Gap exit, so at the downstream arranged second Blade-root. Because of that it is beneficial in the field the second Schaufelfußrands provide a sealing element. The blade root center area forms another subarea of the blade foot. Together with the first and the second Schaufelfußrand stand so different options available, a sealing element in different To arrange portions of the blade root. You will become one in blades having an internal cooling system, wherein a coolant, e.g. Cooling air, through a suitable coolant supply, which is arranged in the blade root center region, the blade is supplied, the sealing element preferably in the region of the first or the second blade root edge Arrange. For blades without such an internal cooling system can also be an arrangement of the sealing element in the area the Schaufelfußmittenbereichs just as advantageous.

Preferably, a plurality of sealing elements are provided. Depending on constructive conditions and requirements regarding the sealing effect to be achieved, the number and Arrangement of sealing elements determined, including combinations can be used from several sealing elements. The Sealing concept offers in terms of adaptation to a concrete task a very high flexibility. For example, seals the combination of a sealing element in the area of first Schaufelfußrands and another sealing element in Area of the second blade root edge the gap from two sides As a result, it provides a great security against both an entry of action fluid into the gap as well against leakage of coolant from the gap in the Flow channel of the turbomachine. An escape from Coolant in the flow channel would inter alia to a Reduction of the efficiency of the turbomachine lead. Also in view of this, is a multiple arrangement of Sealing elements very advantageous.

Preferably, the sealing element extends in a plane perpendicular to the axis of rotation. The gap has a radial and axial extent and an extent in the circumferential direction of the rotor. One in a plane perpendicular to the Rotation axis extending sealing element is therefore suitable especially good, possible axial leakage currents with high Hamper efficiency. For example, an upstream one directed, axial leakage current, e.g. a hot gas out the flow channel of a gas turbine, which extends along the Nutgrundfläche spreads, by the sealing element effectively with special needs. The leakage flow is in this case by the Obstacle delayed in the form of the sealing element in the gap and finally on the leakage flow side facing the Sealing element come to a standstill (simple throttle). The the leakage flow side facing away from the sealing element and in the axial direction adjoining part of the Gaps is caused by the simple sealing element from being acted upon with the leakage medium, e.g. a hot action fluid or a coolant, already protected. A significant improvement this simple solution with a single sealing element, that is in a plane perpendicular to the axis of rotation extends, results from the combination of the sealing element with one or more other sealing elements, the also in a plane perpendicular to the axis of rotation extend and arranged axially spaced from the sealing element are. Through this multiple arrangement of sealing elements possible leakage currents in the gap are considerably reduced.

Preferably, the sealing element is movable in the radial direction. This ensures that the sealing element under Centrifugal force acting in the radial direction of the axis of rotation removed from the rotor. This effect is targeted exploited to a significantly improved sealing effect in the To achieve a gap. The sealing element comes under centrifugal force in contact with a radially outwardly disposed Reaction surface, for example, as part of a Recess, in particular a groove, is configured. The Sealing element is pressed firmly against the reaction surface. By correspondingly advantageous use of centrifugal force as well the reaction forces and their force components on the reaction surface is achieved that the sealing element at the same time in Contact with the groove base comes and firmly to the Nutgrundfläche is pressed. A sufficient radial mobility the sealing element is characterized by suitable dimensioning the recess, in particular the groove, in the blade root and ensured the sealing element.

A further advantage is that thereby the sealing element for any maintenance or failure of the blade without any additional tools and without the risk of one Baking of the sealing element due to an oxidizing or Corrosive attack at high operating temperatures easily Remove from the recess and replace if necessary is. In addition, a certain tolerance of the Sealing element, which in the recess, in particular in the Groove, in the blade root engages very useful, because thereby allowed thermal expansions and thus thermally induced Tensions between the sealing element and the thereto adjacent groove base and the blade root avoided become.

Preferably, the first partial sealing element is a first Turning area with a first axis of rotation and the second Part sealing element a second rotation area with a second Assigned axis of rotation.

Each of the partial sealing elements is thus preferably designed that it is rotatably mounted about a respective axis of rotation is. If the sealing elements are vertical in one plane extend to the axis of rotation of the rotor, the rotation of the Part sealing elements limited in this level. This will an improved seal of the gap allows, because each Part sealing element by the rotation in a favorable sealing position is brought. In this way, for each partial sealing element independently achieved an improved sealing effect. The axis of rotation of a partial sealing element can also as support point (support axis) of the rotation range with a suitable support surface, e.g. with a reaction surface the adjacent to the rotation area, be formed. The reaction surface is advantageously as a partial surface of a recess, in particular a groove, produced in the blade root. The first Rotary axis and the second axis of rotation can from each other be different or identical. In the latter case, this indicates first partial sealing element and the second partial sealing element a common axis of rotation.

Preferably, the center of mass of the first partial sealing element relative to the first axis of rotation and the center of gravity of the second partial sealing element relative to the second axis of rotation arranged so that the results under centrifugal force Torques are directed opposite. By the resulting oppositely directed torques become the partial sealing elements relative to each other in opposite Direction rotated around the respective axis of rotation. The Centrifugal force acts for both partial sealing elements in the same Way radially outward and attacks the respective center of mass at. The vertical connection vector from the center of mass one of the partial sealing elements to the associated axis of rotation forms together with the centrifugal force vector, for example a legal system. In this case, the vertical connection vector forms from the center of gravity of the other partial sealing element to the other partial sealing element associated axis of rotation together with the centrifugal force vector a link system, so that the resulting torques directed opposite are. This is due to appropriate structural design the partial sealing elements in terms of mass distribution, in particular the location of the respective center of gravity, as well as the storage of the partial sealing elements with respect to the axis of rotation ensured.

Preferably, the first partial sealing element and the second Part sealing element similar geometry. The partial sealing elements can thus by turns or reflections or from this combined symmetry operations are transformed into each other become. Manufacturing technology, this is a particularly favorable Solution, especially if the first partial sealing element and the second partial sealing element designed structurally identical are. Then only one form of the partial sealing element is to be produced, which, for example, by a turning or milling process from a workpiece or as a casting with the help a suitable mold is produced. A first partial sealing element and another identical second partial sealing element can thus be easily paired with a sealing element be arranged, which is very inexpensive.

A further improved sealing effect in the gap is achieved in that in a preferred embodiment, the first partial sealing element and the second partial sealing element overlap in the circumferential direction. Due to the overlap in the circumferential direction, a possible axial leakage flow is effectively hindered. The first partial sealing element and the second partial sealing element can each have a groove base sealing edge adjoining the groove base surface and a rotational edge lying opposite the radial direction of the groove base sealing edge, the rotary edge comprising the rotary region. During operation of the rotor, ie under centrifugal force, the groove base sealing edge of the first partial sealing element and the groove base sealing edge of the second partial sealing element respectively come into contact with the groove base surface and seal the gap. The system of partial sealing elements is designed so that a sealing of the gap, in particular in the axial direction, is achieved by overlapping the partial sealing elements in the circumferential direction, wherein the partial sealing elements complement each other advantageously in their sealing effect.
Preferably, the first partial sealing element and the second partial sealing element are arranged axially adjacent to one another. The partial sealing elements can also adjoin one another, whereby a mutually mechanically stabilizing system of partial sealing elements is provided. Sliding of the partial sealing elements for precise reaching their respective sealing position in the operation of the rotor is facilitated. The specified system of partial sealing elements is carried out in such a way adapted that under the action of external forces such as centrifugal force, and the normal and bearing forces, self-adjusted to achieve the desired sealing effect in the gap. Here, in the paired arrangement of the two partial sealing elements to a sealing element, a particularly good positive engagement in the gap, in particular on the groove base realized.

Preferably, the sealing element is made of a highly heat-resistant material, in particular of a nickel-based or cobalt-based alloy, produced. These alloys also have sufficient elastic deformation properties. The material the sealing element is preferably matched with the Material of the rotor is selected, reducing impurities or Diffusion damage can be largely avoided. Furthermore is a uniform thermal expansion or contraction ensures the rotor with the sealing element.

Preferably, the turbomachine is a gas turbine.

The on a sealing element for a rotor of a turbomachine directed object is achieved by a sealing element, in particular for a rotor of a turbomachine, which a first partial sealing element and a having second partial sealing member which is movable relative to each other are, and the first partial sealing element a first Turning area with a first axis of rotation and the second Part sealing element a second rotation area with a second Assigned axis of rotation, wherein the center of mass of the first Part sealing element relative to the first axis of rotation and the Center of mass of the second partial sealing element relative to second axis of rotation are arranged so that under a Force on both partial sealing elements resulting Torques are directed opposite. The force effect on both partial sealing elements can e.g. at a rotating system caused by the centrifugal force. The sealing element is suitable in a special way in a Turbomachine, e.g. a gas or steam turbine or a compressor, with one moving along an axis of rotation extending rotor having a rotor shaft groove with a Nutgrundfläche and a blade with a Blade foot, wherein the blade root used in the Rotorwellennut is, one between the blade root and the groove base To seal the gap formed. The gap is sealed against possible leakage currents, for example from an action fluid or a coolant. The sealing element But it can also be used in other rotating systems where to seal a fluid flow, in particular a leakage flow is to be used. Possible applications of the sealing element are for example given in rotors or wheels of power or prime movers, the hydraulic and / or pneumatic systems with a fluid, e.g. an operating or lubricants (oil), as well as in internal combustion engines or aircraft engines with a resource.

Preferably, the first partial sealing element and the second Part sealing element similar geometry. By symmetry operations like rotation or mirroring or combinations of rotation and reflection can thus be the first Part sealing element and the second partial sealing element into each other be transferred. A particularly advantageous embodiment is that the first partial sealing element and the second Part sealing element constructively identical components are. This ensures that produce only one component is, which e.g. as a casting by means of a mold or made by means of a turning or milling process.

FIG 1

einen Halbschnitt durch eine Gasturbine mit Verdichter, Brennkammer und Turbine,

FIG 2

eine perspektivische Ansicht eines Ausschnitts einer Laufscheibe eines Rotors,

FIG 3

eine perspektivische Ansicht eines Ausschnitts einer Laufscheibe mit eingesetzter Laufschaufel,

FIG 4

einen Ausschnitt einer Ansicht der in Figur 3 gezeigten Anordnung entlang der Schnittlinie IV-IV mit einem Dichtelement,

FIG 5

eine perspektivische Darstellung eines Dichtelements mit einem ersten Teildichtelement und mit einem zweiten Teildichtelement,

FIG 6

eine Draufsicht auf das erste Teildichtelement und das zweite Teildichtelement senkrecht zur Rotationsachse,

FIG 7

eine Seitenansicht einer Laufschaufel mit Innenkühlungssystem und mit einem Dichtelement,

FIG 8

eine Seitenansicht einer Laufschaufel ohne Innenkühlungssystem mit einer gegenüber Figur 7 alternativen Anordnung eines Dichtelements,

FIG 9

eine Schnittansicht eines Ausschnitts eines Rotors mit Umfangsnut und mit eingesetzter Laufschaufel,

FIG 10

eine Schnittansicht eines Ausschnitts eines Rotors mit gegenüber Figur 9 alternativer Ausgestaltung der Laufschaufelbefestigung.

The invention will be described by way of example in the following with reference to the embodiments illustrated in the drawings. Some show schematically and simplified:

FIG. 1

a half section through a gas turbine with compressor, combustion chamber and turbine,

FIG. 2

a perspective view of a section of a rotor of a rotor,

FIG. 3

a perspective view of a section of a running disk with inserted blade,

FIG. 4

3 shows a detail of a view of the arrangement shown in FIG. 3 along the section line IV-IV with a sealing element,

FIG. 5

3 a perspective view of a sealing element with a first partial sealing element and with a second partial sealing element,

FIG. 6

a top view of the first partial sealing element and the second partial sealing element perpendicular to the axis of rotation,

FIG. 7

a side view of a blade with internal cooling system and with a sealing element,

FIG. 8

1 a side view of a blade without an internal cooling system with an arrangement of a sealing element that is an alternative to FIG. 7,

FIG. 9

a sectional view of a section of a rotor with circumferential groove and with inserted blade,

FIG. 10

a sectional view of a section of a rotor with respect to Figure 9 alternative embodiment of the blade attachment.

The same reference numerals have in the individual figures same meaning.

FIG. 1 shows a half section through a gas turbine 1. The gas turbine 1 has a compressor 3 for combustion air, a combustion chamber 5 with burners 7 for a liquid or gaseous fuel, as well as a turbine 9 to drive the compressor 3 and one in the figure 1 not shown generator. In the turbine 9 are fixed Vanes 11 and rotatable blades 13 on each extending radially, not in half-section shown, wreaths along the axis of rotation 15 of the gas turbine 1 arranged. It will be one along the axis of rotation 15 consecutive pair of a ring of vanes 11 (vane ring) and a ring of blades 13 (blade ring) referred to as turbine stage. each Guide vane 11 has a paddle platform 17, which for fixing the relevant vane 11 on the inner Turbine housing 19 is arranged. The paddle platform 17 represents a wall element in the turbine 9. The blade platform 17 forms an outer boundary of the flow channel 21, by the operation of the turbine 9, a hot action fluid A is streaming. The blade 13 is on the along the rotational axis 15 of the gas turbine 1 arranged turbine rotor 23 attached via a corresponding blade platform 17. The turbine runner 23 may be e.g. from several, in Figure 1, not shown, the blades 13 receiving Sliding wheels assembled by a not shown Tie rods held together and by Hirth gearing heat expansion tolerant centered on the axis of rotation 15 are. The turbine runner 23 forms together with the Blades 13, the rotor 25 of the turbomachine 1, in particular the gas turbine 1. In the operation of the gas turbine is air L sucked from the environment. The air L is in the compressor 3 compressed and thereby simultaneously preheated. In the combustion chamber 5, the air is L with the liquid or gaseous Fuel brought together and burned, creating a hot Action fluid A is generated. A previously the compressor 3 off suitable withdrawals 27 removed part of the air L serves as Cooling air K for cooling the turbine stages, e.g. the first Turbine stage with a turbine inlet temperature of about 750 ° C to 1200 ° C is applied. In the turbine 9 takes place a relaxation and cooling of the hot action fluid A, hereinafter referred to as hot gas A, which by the Turbine stages flows while the rotor 25 is rotated. For internal cooling of the blade 13, the cooling air K via the turbine rotor 23 of the blade 13 by suitable, not shown, supply lines supplied. Of the Removal 27 in the compressor 3, the cooling air K flows first along the axis of rotation 15 upstream in the turbine runner 23 and is then radially outward through the Rotor 25 out and finally reaches the blade 13, to cool them. Such an internal cooling system for a blade 13 is particularly at high thermal load Rotors 25 are used for efficient blade cooling.

FIG. 2 shows a perspective view of a detail a running disk 29 of a rotor 25. The running disk 29 is centered along the axis of rotation 15 of the rotor 25. The Running disk 29 has a rotor shaft groove 31 for attachment a blade 13 of the gas turbine 1. The rotor shaft groove 31 extends along a transverse axis 41, opposite a plane perpendicular to the axis of rotation 15 is inclined. The transverse axis 41 forms an angle different from 0 ° with the axis of rotation 15. The transverse axis 41 but can also be parallel to the axis of rotation 15. The rotor shaft groove 31 has a groove base 33, which at the groove bottom of the rotor shaft groove 31 is arranged and moving along the transverse axis 41 extends. The rotor shaft groove 31 is in the form of an axial drive groove, in particular as an axial Tannenbaumnut, designed. In this way is a reliable attachment of a blade 13 possible, wherein during operation of the turbomachine 1 the blade stresses due to flow and centrifugal forces and picked up by blade vibrations with high security can be and a good transfer of occurring Forces on the rotor 29 and finally the whole Rotor 25 is guaranteed.

A perspective view of a section of a rotor 25 is shown in FIG. The rotor 25 has a running disk 29 and a blade 13. The running disk 29 has a rotor shaft groove 31 with a groove base 33. The blade 13 extends radially outward directed longitudinal axis 43 and includes along the longitudinal axis 43 successively a blade root 35, one on the blade root adjacent blade platform 17 and an on the paddle platform 17 adjacent and only partially shown Airfoil 65. In the rotor shaft groove 31 is the Blade 13 with its blade root 35 along the direction of insertion 41 of the pulley groove 31 is inserted. Between the Blade root 35 and the groove base 33, a gap 37 is formed, which extends along the insertion direction 41. A hot gas A flowing past the airfoil 65 generates a torque on the rotor 29. At high operating temperatures the rotor 25 requires the airfoil 65 of the blade 13 an internal cooling, the supply lines 63 in the airfoil 65 along the longitudinal axis 43 of the blade 13 extend. The supply lines 63 are part of an internal cooling system, which is not closer is shown. In this case, a coolant K, for example Cooling air K, through a supply line, not shown by the Run disk 29 in the blade root 35 of the blade 13 passed and from there via the supply line 63 in the Airfoil 65. To escape a coolant K, in particular the cooling air K, from the gap 37 to prevent and limit the entry of the hot gas A into the gap 37, the gap 37 is sealed (see FIG. 4).

FIG. 4 shows a detail of a view in FIG. 3 shown arrangement along the section line IV-IV with a Sealing element 39. The sealing element 39 is for sealing the Slits 37 are provided. The sealing element 39 extends in a plane perpendicular to the axis of rotation 15 and is in one Recess 45, in particular in a groove in the blade root 35th arranged and thereby partially received by the blade root 35. The sealing element 39 has a first partial sealing element 53A and a second partial sealing element 53B, the relative are movable to each other. The first partial sealing element 53A and the second partial sealing element 53B overlap in the circumferential direction and are along the rotation axis 15 to each other arranged adjacent. The first partial sealing element 53A is a first rotation portion 55A having a first rotation axis 57A as well the second partial sealing element 53B, a second rotation region 55B associated with a second axis of rotation 57B. Here are the axes of rotation 57A, 57B through the respective support point (Support axis) of the rotation portions 55A, 55B along the Longitudinal axis 43 radially outward to the rotational areas 55A, 55B adjacent groove bottom of the recess 45 set. The axes of rotation 57A, 57B are different axes and extend essentially parallel to the axis of rotation 15 a rotation of the partial sealing elements 53A, 53B about the respective Rotation axis 57A, 57B allows. The partial sealing elements 53A, 53B can both by their design and arrangement both Perform rotations as well as translations or combinations from twists and translations. In operation of the rotor 25 the sealing element 39 seals the gap 37 under centrifugal force from. At this time, each of the sub-sealing members 53A, 53B becomes due to the radially outward along the longitudinal axis 43 Centrifugal force brought into its sealing position and unfolded its sealing effect. Each partial sealing element 53A, 53B becomes while firmly pressed against the groove base 33 and seals the gap 37 from. The sealing effect is achieved in that each sub-sealing element 53A, 53B under the centrifugal force performs a rotation about the respective axis of rotation 57A, 57B until a positive contact of the partial sealing elements 53A, 53B is made with the groove base 33. By the Relative mobility of the partial sealing elements 53A, 53B results a matched to the gap geometry system, which depends from the thermal and / or mechanical stress the rotor 25 and the structural design of the sealed Gap 37 is made. The system from relative to each other movable partial sealing elements 53A, 53B is so designed to be under the influence of external forces, such as the centrifugal force and the normal and bearing forces (Reaction forces), as it were self-adjusting, and thereby assumes its sealing position. The partial sealing elements 53A, 53B are configured and mounted in the recess 45, that under centrifugal force the torque on the first sub-sealing element 53A directed opposite to Torque on the second part of the device 53B is. Thereby make the partial sealing elements 53A, 53B to reach their sealing position one rotation with opposite Rotation. Through these oppositely directed turns the partial sealing members 53A, 53B become relative to each other moved scissor-shaped, causing in the sealing position ensures a special secure hold of the sealing element 39 is. The sealing element 39 comprising the paired partial sealing elements 53A, 53B, seals the gap 37 at the groove base 33 against the directed in the direction of the longitudinal axis 43 Centrifugal force. By the sealing element 39 is thus a particularly advantageous and efficient sealing of the gap 37 reached. Through the movable pair of partial sealing elements 53A, 53B, which are arranged paired with the sealing element 39, Beyond that also possible thermally or mechanically induced voltages significantly better balanced than at conventional seals.

A preferred embodiment of the sealing element shown in Figure 4 39 is shown in FIG. FIG. 5 shows a perspective view of a sealing element 39 with a first partial sealing element 53A and with a second partial sealing element 53B. Here, the center of mass 59A of the first Part sealing member 53A relative to the first axis of rotation 57A and the center of gravity 59B of the second partial sealing element 53B is disposed relative to the second rotation axis 57B so that the under the action of the along the longitudinal axis 43 radially outwardly directed centrifugal force resulting torques 61A, 61B are directed opposite. The first partial sealing element 53A and the second partial sealing element 53B point in this case similar geometry, which manufacturing technology especially is advantageous.

FIG. 6 shows a plan view of the first partial sealing element 53A and the second partial sealing element 53B according to FIG. 5 are vertical to the axis of rotation, ie opposite to the longitudinal axis 43. Relative to the axis of rotation 15 is the center of mass 59A of the first partial sealing element 53A along the circumferential direction 67 the center of mass 59B of the second partial sealing element 53B opposite. The same applies to the partial sealing elements 53A, 53B associated rotary axes 57A, 57B, so that the under a force on both partial sealing elements 53A, 53B resulting torques oppositely directed are. The two partial sealing elements 53A, 53B are relative to one another, for example, along the circumferential direction 67, movable. As a result, in the installed state of the sealing element 39 (see Figure 4) under centrifugal force of the Gap 37 effectively sealed, with the partial sealing elements 53A, 53B after execution of a limited relative Translation and rotation to achieve their respective sealing position. In this case, the partial sealing elements 53A, 53B complement each other in their sealing effect, so that in particular leakage currents along the axis of rotation 15 are limited very efficiently. At the Use of the sealing element 39 for a rotor 25 of a turbomachine 1, for example, a gas turbine 1, one chooses as a material for the sealing element 39, a highly heat-resistant material, which also has sufficient elasticity Has deformation properties. For this example comes Alloys based on nickel or cobalt in question.

The sealing element 39 with the paired arrangement of Part sealing elements 53A, 53B may be in different ways be used for sealing. To illustrate this, shows Figure 7 is a side view of an internally cooled blade 13 with a sealing element 39A and with another Sealing element 39B. The blade 13 is with her blade foot 35 inserted into the rotor shaft groove 31 of the rotor disk 29. The blade root 35 has a first blade root edge 47 and one along the axis of rotation of the first Schaufelfußrand 47 opposite second blade root edge 51 on. Axial between the first blade root edge 47 and the second End of the blade 51, a Schaufelfußmittenbereich 49 is arranged. With respect to the flow direction of the flowing hot gas A is the first blade root edge 47 upstream and the second blade root edge 51 is located downstream. In the Running disk 29 and in the Schaufelfußmittenbereich 49 Coolant bushings 63 are provided which extend along the Longitudinal axis 43 extend and in flow communication with the Interspace 37 are. The coolant passages 63 are Part of an internal cooling system, not shown in Figure 7 for the blade 13. For internal cooling of the blade 13, a coolant K, e.g. Cooling air, through the Coolant passages 63 and is through the internal cooling system through the blade platform 17 and which is radially subsequent blade sheet 65 of the blade 13 out. To prevent the gap 37 from escaping coolant K is the first sealing element 39A in the region of first Schaufelfußrands 47 and the second sealing element 39 B in Area of the second Schaufelfußrands 51 arranged. The Sealing elements 39A, 39B are each in a recess 45, in particular in a groove, arranged in the blade root. there the sealing elements 39A, 39B of the blade root 35 are partially added.

As described in Figures 4 to 6, but for reasons of clarity not shown in Figure 7, the sealing elements 39A, 39B each as a system of two arranged in pairs Partial sealing members 53A, 53B (see, for example, FIG 5) designed. In operation of the rotor 25, i. under the influence one directed along the longitudinal axis 43 radially outwardly Centrifugal force, enter the partial sealing elements 53A, 53B then in contact with the groove base 33 and seal the Gap 37 from. In this case, the sealing element 39A seals the gap on first blade root 47 and the sealing member 39B the gap 37 at the downstream arranged second Schaufelfußrand 51st from. This embodiment offers great security both against the entry of hot gas A into the gap 37 as well towards the exit of coolant K from the gap 37 in FIG the flow channel 21 (see Figure 1) of the rotor 25. An escape of coolant K in the flow channel 21 would be under lead to a reduction in the efficiency.

FIG. 8 shows a side view of a blade 13 without Internal cooling system with an alternative to Figure 7 alternatives Arrangement of a sealing element 39A and another sealing element 39B. In this case, the sealing element 39A is in the region of first Schaufelfußrands 47 and the sealing element 39B in the area the Schaufelfußmitten 49 arranged. The order the sealing element 39A primarily limits the entrance of flowing hot gas A in the gap 37 and prevented thus damaging the rotor 25. By the combination of the sealing member 39A and the other sealing member 39B achieved a correspondingly greater sealing effect. The specified Sealing concept offers in terms of customization a specific task a very high flexibility. A multiple arrangement of sealing elements 39A, 39B is included of particular advantage.

In addition to the attachment of a blade 13 in a substantially axially directed rotor shaft groove 31 of a running disk 29 (axial groove) are also other blade fasteners known. The application of the sealing element 39 shown at alternative blade mountings is below illustrated in Figures 9 and 10.

FIG. 9 is a sectional view of a detail of FIG Rotor 25 with rotor shaft groove 31 and with inserted blade 13 is shown. The rotor shaft groove 31 is as Circumferential 31 performed in the rotor shaft 23. The circumferential groove 31 is made as a so-called Hammerkopfnut, the Shovel foot 35 receives. For short blades 13 with small ones Centrifugal forces and bending moments becomes this form of blade attachment preferably used. In the blade root 35 is a recess 45, in particular a groove into which a Sealing element 39 engages. The sealing element 39 extends in the circumferential direction of the rotor shaft 23 and seals the gap 37th from. The sealing element 39 seals the gap in this case Fliehkrafteinwirkung and can from two in the circumferential direction overlapping and relatively movable, in 9, not shown, partial sealing elements 53A, 53B assembled be as described for Figure 5. At rotation the rotor shaft 23 about the rotation axis 15 is the Sealing element 39 under centrifugal force firmly to the groove base 33 pressed. As a result, the gap 37 is sealed.

FIG. 10 shows a sectional view of a section of a Rotor 25 with respect to Figure 9 alternative embodiment the blade attachment. Here is the circumferential groove 31 produced by a so-called Umfangstannenbaumnut. The blade root 35 of the blade 13 is accordingly produced as Tannenbaumfuß, in the circumferential groove 31, in particular in the Umfangstannenbaumnut 31, engages. By this type of attachment of the blade 13 is during rotation of the rotor 25 about the axis of rotation 15 is a very effective Power transmission to the rotor shaft 23 and a particular secure hold achieved. Analogous to Figure 9 is in the Blade foot 35 a recess 45 is provided in the one Sealing element 39 is arranged. The sealing element 39 serves for Sealing of the gap 37, between the blade root 35 and the groove base 33 is formed.

The stated concept for sealing the gap 37 by means of a Sealing element 39, or a pair of relative to each other movable partial sealing members 53A, 53B, is in each Case very flexibly transferable to a rotor 25, whose blade 13 is mounted in a circumferential groove 31.

Claims (15)

1. Fluid-flow machine (1) comprising a rotor (25) which extends along a rotation axis (15) and has a rotor-shaft slot (31) having a slot root surface (33) and a moving blade (13) having a blade root (35), the blade root (35) being inserted into the rotor-shaft slot (31), and a gap (37) being formed between the blade root (35) and the slot root surface (33), and a sealing element (39) being provided for sealing the gap (37), wherein the sealing element (39) is arranged in a recess (45) in the blade root (35) and is at least partly accommodated by the blade root (35), wherein the sealing element (39) is movable relative to the blade root (35), and wherein the sealing element (39) is in contact with the slot root surface (33) under the effect of centrifugal force and thereby seals the gap (37), characterized in that the sealing element (39) has a first sealing element section (53A) and a second sealing element section (53B) which are movable relative to one another.
2. Fluid-flow machine (1) according to Claim 1, characterized in that the rotor (25) has a moving disc (29) which comprises the rotor-shaft slot (31) with the slot root surface (33), the rotor-shaft slot (31) extending along a transverse axis (41) which is inclined relative to a plane perpendicular to the rotation axis (15).
3. Fluid-flow machine (1) according to either of Claims 1 and 2, characterized in that the blade root (35) has a first blade-root margin (47) and a second blade-root margin (51), located opposite the first blade-root margin along the rotation axis, and a blade-root centre region (49) which is arranged axially between the first blade-root margin (47) and the second blade-root margin (51), a sealing element (39) being arranged in the region of the first blade-root margin (47) and/or of the second blade-root margin (51) and/or of the blade-root centre region (49).
4. Fluid-flow machine (1) according to one of the preceding claims, characterized in that a plurality of sealing elements (39) are provided.
5. Fluid-flow machine (1) according to one of the preceding claims, characterized in that the sealing element (39) extends in a plane perpendicular to the rotation axis (15).
6. Fluid-flow machine (1) according to one of the preceding claims, characterized in that the sealing element (39) is movable in the radial direction (43).
7. Fluid-flow machine (1) according to one of the preceding claims, characterized in that a first rotary region (55A) having a first rotary axis (57A) is assigned to the first sealing element section (53A), and a second rotary region (55B) having a second rotary axis (57B) is assigned to the second sealing element section (53B).
8. Fluid-flow machine (1) according to Claim 7, characterized in that the mass centre (59A) of the first sealing element section (53A) is arranged relative to the first rotary axis (57A) and the mass centre (59B) of the second sealing element section (53B) is arranged relative to the second rotary axis (57B) in such a way that the torques (61A, 61B) resulting under the effect of centrifugal force are opposed.
9. Fluid-flow machine (1) according to Claim 7 or 8, characterized in that the first sealing element section (53A) and the second sealing element section (53B) have similar geometry.
10. Fluid-flow machine (1) according to one of Claims 7, 8 or 9, characterized in that the first sealing element section (53A) and the second sealing element section (53B) overlap in the circumferential direction.
11. Fluid-flow machine (1) according to one of Claims 7 to 10, characterized in that the first sealing element section (53A) and the second sealing element section (53B) are arranged axially adjacent to one another.
12. Fluid-flow machine (1) according to one of the preceding claims, characterized in that the sealing element (39) is made of a high-temperature-resistant material, in particular a nickel-base or cobalt-base alloy.
13. Fluid-flow machine (1) according to one of the preceding claims, characterized by a configuration as a gas turbine (1).
14. Sealing element (39), in particular for a rotor (25) of a fluid-flow machine (1), which has a first sealing element section (53A) and a second sealing element section (53B) which are movable relative to one another, and a first rotary region (55A) having a first rotary axis (57A) is assigned to the first sealing element section (53A), and a second rotary region (55B) having a second rotary axis (57B) is assigned to the second sealing element section (53B), the mass centre (59A) of the first sealing element section (53A) being arranged relative to the first rotary axis (57A) and the mass centre (59B) of the second sealing element section (53B) being arranged relative to the second rotary axis (57B) in such a way that the torques (61A, 61B) resulting on both sealing element sections (53A, 53B) under an effect of a force are opposed.
15. Sealing element (39) according to Claim 14, characterized in that the first sealing element section (53A) and the second sealing element section (53B) have similar geometry.

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