EP2884052B1 - Rotor for a turbomachine having a closed flow contour ring and method for manufacturing the same - Google Patents

Description

The invention relates in essence to a turbine machine designed as a turbine or as an axial compressor, along the flow path alternately rows of fixed to a rotatable support vanes and blades attached to a rotor follow one another, wherein at least one of the vane rows comprises free-standing vanes and one of this vane directly adjacent Blade rows includes blades, which are each inserted in at least partially extending in the axial direction retaining grooves. Furthermore, the invention relates to a method for producing a rotor of a compressor from a plurality of rotor base elements.

Turbomachines and axial compressors are known in a variety of ways from the extensive state of the art. Basically, they have sequentially rows of blades, which are either made of vanes attached to a non-rotatable support. The carrier may, for example, be designed as a guide blade carrier or as a housing. Both are annular structures in whose interior a rotor is rotatably mounted. Or the rows are formed of blades, which are usually attached to a shaft collar of the rotor.

The blades of the blades are disposed in the annular flow path, which typically extends axially between the carrier and the rotor. For fastening the guide vanes and blades in rows different concepts are known in the art: both Vanes as well as blades can be inserted in their corresponding carrier (the vane support or on the rotor) in circumferential grooves. Frequently, the circumferential grooves then have a hammer-shaped contour in cross-section, into which the correspondingly executed blade roots of the guide vanes or moving blades are inserted. With blades arranged in circumferential grooves, all blades of a row sit in one and the same groove. These blades are referred to as blades having a radial foot design. Alternatively, it is known for blades that instead of a common circumferential groove for each blade a separate retaining groove is present, which then extends in each case mainly in the axial direction of the rotor. In the latter case, the mutually corresponding contours of retaining groove and blade root are then dovetail-shaped or fir tree-shaped. These foot constructions are referred to below as Axialfußdesign.

All blades are attached at least the foot side. With reference to annular flow paths, the guide vanes are thus fastened radially on the outside of the flow path boundary, and the rotor blades are radially inward.

For both blades and vanes, it is known to allow the head end of the blades to end freely. These freestanding blades then have blade tips that are shaped by the blade itself. Instead, it is also known for both vanes and buckets to provide platforms at the head ends of the airfoils which are coupled to the adjacent vanes of the particular vane ring. Such blades are also referred to as shroud blades. Furthermore, it is known for vanes that their head ends are rigidly coupled via a common inner ring. This thus arranged hub side inner ring simultaneously forms the local boundary of the flow path.

However, it has been found that in turbomachines whose housing has a parting line, some combinations of these different constructions are difficult or impossible to implement. Such turbomachines are assembled so that their fitted with blades rotor is first inserted into a lower half of the housing, after which the rotor is then covered by placing the upper half of the housing on the lower. This is also known as a radial design and is in contrast to a Axialbauweise, as found in aircraft engines application. In turbomachines in radial design freestanding vanes require a rotor-side mostly rotationally symmetrical wall surface on the rotor, which faces the tips of the free-standing vanes and locally limits the flow path radially inward. This requirement has heretofore made it impossible to use axial foot design blades because their retaining grooves require clearance at the same location to first position the blades at the appropriate radius during assembly and then push them into the respective retaining groove by the axial sliding motion can.

Due to the need for free space at the side of the retaining groove, an inner ring guide design was mostly used at these axial positions when directly next to it axial blade design blades were used.

In principle, blades with a radial foot design are more expensive to produce compared to blades with Axialfußdesign. Guide vanes, which have an inner ring on the head side, are very complex in manufacture and assembly. In addition, these are susceptible to interference in operation. Furthermore, a seal between the inner ring and the rotor is required, which increases the complexity of the system, if only small leaks are desired.

Next has been found to be disadvantageous that free-standing vanes applying an abrasive Layer on the rotor in the area between two rows of blades is only laboriously feasible and leads to an expensive production.

For these reasons, there is a desire to be able to use freestanding guide vane design with blades having Axialfußdesign at any point of the turbomachine. In the prior art, for example, discloses DE 1 196 017 a drum rotor for axial flow machines, in which a separable intermediate ring between the wheels of two adjacent disks is provided to cover the gap there existing. In the separation region of the intermediate ring is stepped or sawtooth designed so as to provide an inwardly compressible end. Pressed inward, one of the lateral openings of the axial grooves is exposed by the blade, so that subsequently the latter can be removed from the rotor. It is considered to be disadvantageous that the ring is separable and thus must be secured against separation during operation of the turbomachine.

Instead of a gap between two adjacent rings covering the intermediate ring is from the US 2,683,583 A1 a closed ring is known, which can be axially displaced to a side wall of the rotor in order to close the arranged in this side wall insertion openings of retaining grooves. The disadvantage, however, is that this concept is only applicable to the front blade row of a compressor, but not for blade rows arranged downstream thereof.

The object of the invention is therefore to provide a rotor for a preferably made in radial construction Turbomachine and a preferably produced in radial flow machine of the type mentioned, in which in particular repeatedly freestanding vanes of a row of vanes can be arranged immediately adjacent to seated in axial holding blades blades.

The object underlying the invention is achieved with a rotor for a turbomachine according to the features of claim 1. In addition, the object directed to the turbomachine with a turbomachine according to the features of claim 11 is achieved. Furthermore, the features of claim 16 solve the problem of specifying a method for producing a rotor for a turbomachine.

Overall, a technical solution is presented with the invention, as the previously annular space, which is required in addition to a shaft collar for the assembly of blades with Axialfußdesign, can be completely closed by a cover, the cover can simultaneously represent the hub-side boundary of the flow channel. This ensures that immediately adjacent to said blades with Axialfußdesign the vanes can be carried out freestanding, ie without resort to inner ring design of vanes.

The rotor for a turbomachine with an annular cross-sectional flow path thus comprises at least one endless shaft collar, in which at least partially axially extending retaining grooves are provided, each with a seated therein blade to form a blade ring, wherein the rotor comprises at least one Strömungskonturring, which at least one , Which has at most four radially outwardly facing openings as access to a corresponding number of available segment clearances, which segment free space or which segment clearances are open at least on one side, preferably on both sides, and wherein the flow contour ring and / or the remaining rotor means for fixing a closing the access Closing device and wherein said flow contour ring is arranged laterally of the respective shaft collar and whose or their accesses in each case by a respective flow contour ring and / or the rest e rotor attached closure device is closed.

In this respect, the closed flow contour ring is arranged in particular during assembly of the rotor base elements between the two immediately adjacent rotor base elements, in particular with built-rotors. This largely fills the previously free for the assembly of the blades annular space between the adjacent rotor base elements and leaves at least one segment clearance. Each segment free space extends only over a part of the circumference of the flow contour ring and is usually chosen only so large that it is at most slightly larger than the pitch of the adjacent blade ring. Thus, one to four segment clearances are now provided instead of the previous Ringfreiraumes. The segment clearances serve in the absence of closure device on the one hand for the disassembly / assembly of the blades and for the placement of a de- or mounting device such as a hydraulic cylinder, by means of which the blades can be pushed out into the holding or out of the holding. Thus, the closed flow contour ring and the corresponding to the segment clearances in Number of existing closure devices collectively a cover that closes the previous ring clearance so that a flow-free hub-side boundary is formed in the axial region of freestanding vanes.

When this rotor is installed in a turbomachine, the flow contour ring according to the invention forms the hub-side boundary of the flow channel in the axial section of the freestanding guide vanes.

After producing the bladeless rotor with the two rotor base elements and the flow contour ring arranged therebetween, a moving blade is to be inserted into each of the retaining grooves provided in the shaft collar. At least one segment free space is not yet closed by the associated closure device, but open. To assemble each blade, the closed flow contour ring relative to the two rotor base elements is to be rotated in the circumferential direction such that its segment clearance is arranged so that the foot of the relevant blade can be immersed in it from radially outside. Then it can be inserted into the lateral opening of the retaining of said blade root until it is completely absorbed by the retaining groove. Then, the flow contour ring can be rotated in the circumferential direction to the next holding groove according to the pitch of the blade ring, in which then the next blade is mounted in the same manner. These steps are repeated until all the blades of the ring are mounted on the respective shaft collar. Subsequently, the closure device is attached to the closed flow contour ring, whereby the radially outwardly facing opening of the segment space is closed flat and flush.

In principle, it is sufficient if the flow contour ring has only one segment free space with the radially outwardly facing opening. For reasons of symmetry and out Because of the imbalance of the rotor, a slightly larger number of segment clearances and thus openings can be provided. Expedient upper limit seems to represent a number of four segment clearances, since otherwise the effort to close the respectively outwardly facing opening is too costly.

The closed flow contour ring also comprises an outwardly facing surface, which may be cylindrical, frusto-conical or even a curved truncated cone shape. In principle, it is still rotationally symmetrical, since this opposite to the tips of the vanes in the installed state of the rotor. The rotational symmetry may possibly be excluded if a so-called "stroke-treatment" is arranged opposite the blade tips of the freestanding guide vanes.

Thus, using the closed flow contour ring, it is possible to provide a radial flow machine having an annular flow path along which vanes of fixed support and rotor-mounted blades successively follow one another, with at least one of the vanes comprising free-standing vanes and one the blade vane immediately adjacent this vane ring comprises blades which are each inserted in at least partially axially extending retaining grooves of the rotor, wherein the rotor and its associated flow contour ring is configured such that it faces the tips of the free-standing vanes.

With the aid of the claimed subject matter, it is possible to provide a total of a preferably radially constructed flow machine, which allows the advantages of free-standing vanes with blades held in axial grooves in the immediate vicinity.

If in the present patent application of a free space on the side of the retaining grooves is concerned, the term "laterally" refers to one or both axially adjacent portions of that shaft collar in which the holding grooves for blades are arranged.

Further advantageous features of the invention are specified in the dependent claims.

Preferably, the flow contour ring may be made of metal or of glass or carbon fiber reinforced plastic. Since the use in rows of blades is possible, which are exposed to relatively low thermal influences, can be used as a plastic material. The use of plastic is inexpensive and provides a durable and low-weight solution. By contrast, the use of metal is also suitable, especially at higher operating temperatures.

According to a further advantageous development, a flow contour ring is provided on both sides of the respective shaft collar. This allows in the service case by dismantling each wall element access to mounting space to position on the one hand a tool for pushing out the blade therein, which tool can then push the dismantling blade into the other mounting space available.

According to a further advantageous embodiment, the radially outwardly facing surface of the flow contour ring and / or the closure element is coated. According to this concept, the layers are to be integrated as abradable layers - possibly called abradables - in a further groove on the outer circumference of the flow contour ring.

Expediently, the access in question, the relevant frontal opening and the segmental clearance in question have a size such that at least one, but no more than two blades of the immediately adjacent ring can be assembled or disassembled at the same time. With the help of this measure, the size of the closure device, with which the radially outwardly facing opening of the segmental clearance is to close, be designed physically small, which reduces their tendency to loss or for release.

According to a further advantageous embodiment of the flow contour ring and its closure devices are designed such that they block a displacement of the mounted blade along its retaining groove on one side. On this side of the retaining then no further measures are required to prevent the displacement of the blade along the retaining. In this respect, hereby a comparatively simple, as cost-effective solution is provided as axial securing.

According to a first embodiment of a closure device, this may be integrally formed screwed to the flow contour ring. In this case, the closure device is relatively easy to manufacture, wherein it has proved to be advantageous when the screws are in turn secured against loosening.

An alternative closure device can be configured in several parts in the manner of a closure piece for circumferential grooves of rotor blade rings. Such closure pieces are known from the extensive prior art.

Alternatively, the closure device may comprise a cover member closing the access flush and an intermediate piece, wherein the intermediate piece is seated radially positively in the flow contour ring and screwed to the cover element. This also represents a comparatively inexpensive and easy to install closure device that closes the access permanently and reliably.

Because, during assembly of multiple blades and / or during disassembly of multiple blades, the flow contour ring freed from at least one shutter is to be rotated about the axis of rotation until the segment clearance is at the appropriate position where the blades are to be installed proved to be useful when the flow contour ring has radially inwardly two to five Gleitkontaktbereiche to the rest of the rotor. This ensures low adjustment forces. Also, with the help of an additional adjustment in the groove in which the flow contour ring sits, the service friendliness increased and the adjustment force can be further reduced by a leverage.

Overall, the turbomachine can be designed either as an axial turbine or as an axial compressor. The axial compressor may in particular be that of a stationary gas turbine.

Overall, the invention achieves the following advantages: Guide plates, in which the guide vanes are coupled radially outwards and radially inward via rings, can be dispensed with. These can be replaced by freestanding vanes. This results in savings in manufacturing, storage and production management costs for the components. In addition, despite the use of Axialfußschaufeln a destacking of the rotor in case of service is no longer necessary. At the same time, there are lower leakage flows between the blade tips and the opposite flow contour rings compared to the constructions with inner rings which are to be sealed off from the rotor.

It should also be noted that the rotor basic elements can not only be comparatively solid rotor elements with a comparatively large axial extension. The rotor basic elements can also be designed in each case as wheel discs, in particular when the rotor is in modular Construction is composed of a plurality of such wheel discs. Such rotor disks can be clamped together either via a central tie rod or via a plurality of decentralized tie rods.

In principle, it lends itself to the fact that the flow contour ring is designed comparatively solid away from its segmental clearance, so that it can be designed as a self-supporting construction. Instead of a comparatively massive design, it is also possible for the flow contour ring to be substantially a sheet metal construction comprising some circumferentially distributed and / or extending struts for radial and lateral support.

In principle, the closed flow contour ring has a width which is detected in the axial direction and which is only slightly larger than the width of the endless shaft collar, likewise detected in the axial direction, in which the rotor blades are inserted.

On the whole, the invention provides a closed flow contour ring for a rotor, a rotor for a turbomachine and a turbomachine, which can be configured in such a way by using the flow contour ring according to the invention in a rotor and by using a rotor in a turbomachine. that, in particular, repeatedly freestanding guide vanes can be arranged directly axially adjacent to rotor blades, which in turn are inserted into at least partially axially extending retaining grooves. To accomplish this, a closed flow contour ring is suggested which is mounted on the rotor adjacent a shaft collar having the retaining grooves of axial blade design vanes and which has a laterally and outwardly openable lockable segment clearance for removal of a blade.

Further advantages and features of the invention will be explained in more detail with reference to further embodiments.

FIG 1

einen Ausschnitt durch den Längsschnitt eines Axialverdichters nach dem Stand der Technik mit freistehenden Laufschaufeln, die in Axialnuten befestigt sind und mit Leitschaufeln, deren kopfseitige Enden an einem Innenring miteinander gekoppelt sind,

FIG 2

einen Ausschnitt durch den Längsschnitt eines Axialverdichters nach dem Stand der Technik mit freistehenden Leitschaufeln sowie mit freistehenden Laufschaufeln mit Radialfußdesign,

FIG 3

eine perspektivische Darstellung eines Teils eines Rotors mit zwei Wellenbünden und einem dazwischen angeordneten Strömungskonturring,

FIG 4

den Strömungskonturring in perspektivischer Darstellung,

FIG 5

die Verschlussvorrichtung für den Strömungskonturring gemäß FIG 4,

FIG 6

einen Längsschnitt durch den Rotor gemäß FIG 3,

FIG 7

ein zweites Ausführungsbeispiel eines Strömungskonturrings mit einem zweiten Ausführungsbeispiel einer Verschlussvorrichtung,

FIG 8

in perspektivischer Darstellung die Verschlussvorrichtung gemäß des zweiten Ausführungsbeispiels,

FIG 9

den Strömungskonturring gemäß des zweiten Ausführungsbeispiels, eingebaut in einen Rotor,

FIG 10

einen Strömungskonturring gemäß eines dritten Ausführungsbeispiels in Art einer Blechkonstruktion,

FIG 11

eine zum Strömungskonturring gemäß des dritten Ausführungsbeispiels passende Verschlussvorrichtung,

FIG 12

den Längsschnitt durch einen Rotor einer Strömungsmaschine mit einem Strömungskonturring gemäß des dritten Ausführungsbeispiels und

FIG 13,

14, 15 und 16 das schrittweise Verfahren zur Demontage einer Laufschaufel aus einer sich teilweise in Axialrichtung erstreckenden Haltenut unter Verwendung eines geschlossenen Strömungskonturrings mit einer radial nach außen weisenden Öffnung zu einem Segmentfreiraum.

Show it:

FIG. 1

a section through the longitudinal section of a prior art axial compressor with free-standing blades, which are mounted in axial grooves and with vanes whose head-side ends are coupled to each other on an inner ring,

FIG. 2

1 a section through the longitudinal section of a prior art axial compressor with free-standing vanes and with free-standing rotor blades with radial foot design,

FIG. 3

a perspective view of a portion of a rotor with two shaft collars and a flow contour ring arranged therebetween,

FIG. 4

the flow contour ring in perspective,

FIG. 5

the closure device for the flow contour ring according to FIG. 4 .

FIG. 6

a longitudinal section through the rotor according to FIG. 3 .

FIG. 7

A second embodiment of a flow contour ring with a second embodiment of a closure device,

FIG. 8

in a perspective view of the closure device according to the second embodiment,

FIG. 9

the flow contour ring according to the second embodiment, installed in a rotor,

FIG. 10

a flow contour ring according to a third embodiment in the manner of a sheet metal construction,

FIG. 11

a closure device suitable for the flow contour ring according to the third embodiment,

FIG. 12

the longitudinal section through a rotor of a turbomachine with a flow contour ring according to the third embodiment and

FIG. 13,

14, 15 and 16 show the step-by-step method of disassembling a blade from a partially axially extending retaining groove using a closed flow contour ring with a radially outwardly facing opening to a segment clearance.

All embodiments illustrate the invention with reference to an axial compressor, which is representative of any turbomachinery. In all figures, identical features are provided with the same reference numerals.

FIG. 1 shows a section of a longitudinal section through an axial compressor 10 of the prior art, in which 12 guide vanes 14 are arranged in rows on a rotatable carrier. The vanes 14 are hooked with their blade root 16 in the blade carrier 12 in any desired manner. On the blade ends 16 opposite the head ends of the guide vanes 14 so-called inner rings 18 are provided, which couple the blades of the vanes 14 in a row. The inner rings 18 are arranged in a free space 20 which is arranged axially between two shaft collars 23 of adjacent wheel disks 22, in each of which retaining grooves 24 are arranged. In the retaining grooves 24 blades 26 are inserted. The retaining grooves 24 extend substantially in the axial direction, that is, they can also be employed against the axial direction. The side of the shaft collars 23 existing clearances 20 allow for a rotor 19, the subsequent mounting of blades 26. The rotor 19 includes individual wheel discs 22 which are braced by a tie rod 28 together.

According to FIG. 1 hitherto, the inner rings 18 formed the hub-side boundary of the flow path 13 in the region of the guide vanes 14, whereas according to FIG FIG. 2 the hub-side boundary of the flow path 13 is formed by the outer peripheral surfaces 40 of the rotor disks 42.

In particular in axial compressors in radial construction instead of guide vanes 14 with inner rings 18 freestanding guide vanes 34 (FIGS. FIG. 2 ), had in the prior art - shown in FIG. 2 - The blades 36 are arranged in circumferential grooves 38 which are provided on the outer peripheral surfaces 40 of the rotor discs 42. The outer peripheral surfaces 40 of the rotor disks 42 also delimit the flow path 13 of the compressor 10 away from the rotor blades 36, which is annular in cross-section and in which the blades of the blades 14, 26, 34, 36 are arranged for compressing the working medium. Like from the FIGs. 1 and 2 shows the wreaths are arranged concentrically to a central axis 15.

Order now the in FIG. 1 illustrated blades 26 with Axialfußdesign immediately adjacent freestanding vanes 34 according to FIG. 2 to be used in turbomachinery in particular with radial design, which is in the FIGS. 3 to 12 shown embodiments of rotors 21 proposed.

For the sake of clarity is in the FIGS. 3 to 12 only a blade shown. The following exemplary embodiments are described with reference to a rotor 21, which has a plurality of rotor base elements 25, hereinafter referred to as wheel disks 22. According to the in the FIGS. 3 and 4 illustrated embodiment, the rotor 21 comprises at least two immediately adjacent rotor base elements 25, which are designed as wheel discs 22. At the wheel disks 22, a shaft collar 23 is provided on the outside, in which the retaining grooves 24, which are usually inclined to the axial direction, are arranged. Between the shaft collars 23 there is a clearance 20 which is required to push the blades 26 into the retaining groove 24. The free spaces 20 may be located in those axial portions of the rotor 21, in which both wheel disks 22 extend axially into it. After assembly of the blades 26 in the retaining grooves 24, the access to the free spaces 20 are flat and continuously cover for the flow.

FIG. 3 shows in perspective two directly adjacent wheel discs 22. The wheel discs 22 each have the shaft collar 23, in which along the circumference uniformly distributed retaining grooves 24 are provided for blades 26. The retaining grooves 24 are opposite the rotation axis 15 (FIG. FIGs. 1 and 2 ) slightly inclined. However, they can also be aligned exactly parallel to the axis of rotation 15 of the rotor 21.

The outwardly facing surfaces 45 of the shaft collars 23 are hub-side boundary surfaces for the flow path of the turbomachine.

Between the two shaft collars 23 a self-contained flow contour ring 46 is arranged. A closure device 48 is secured in the flow contour ring 46. The outwardly facing surfaces of the flow contour ring 46 and the closure device 48 are aligned with the outwardly facing surfaces 45 of the shaft collars 23, so that a stepless boundary of the flow path is ensured on the hub side.

The closed flow contour ring 46 is in FIG. 4 shown in perspective. The flow contour ring 46 has at least one segment clearance 49 which includes a radially outwardly facing opening 50 for access to the segment clearance 49. Further, the segment clearance 49 is open at both end side surfaces of the flow contour ring 46.

The in FIG. 4 shown in perspective flow contour ring 46 is made comparatively solid and has on its inner side segment-shaped grooves 52, which reduce the weight of the Strömungskonturrings 46. At two immediately opposite positions, the inner surface of the flow contour ring has inwardly projecting sliding contact surfaces 54 such that at these sliding contact surfaces 54, the flow contour ring 46 may contact the remainder of the rotor. Instead of two sliding contact surfaces 54, three or optionally even more sliding contact surfaces can be provided. It is advantageous in any case, if not the entire inwardly facing surface of the flow contour ring 46 is in sliding contact with the rest of the rotor.

In the region of the segment clearance 49, the flow contour ring 46 has only a comparatively small material thickness in the radial direction, in which holes 56 can be provided according to the exemplary embodiments illustrated here. The opening 50 of the segmental clearance 49 can be closed by means of a closure device 48. A first embodiment of a closure device 48 is shown in FIG FIG. 5 shown in perspective. De facto, the closure device 48 is made in one piece as a cuboid with two holes 51st

FIG. 6 shows the longitudinal section through two immediately adjacent rotor disks 22 and arranged between the shaft collars 23 Strömungskonturring 46 and the closure device mounted thereon 48. Due to the employment of the retaining grooves 24 relative to the axial direction is similar to their representation a circumferential groove, which they are not. After complete assembly of all blades 26 of both rings, the closure device 48 is inserted into the segmental clearance 49 of the flow contour ring 46, so that the radially outwardly facing opening 50 is completely closed, except for the openings in the closure device 48 for receiving the screws. The holes 56 provided in the flow contour ring 46 are aligned with the bores 51 of the closure device 48, so that screws can be screwed to the rotor disks 22, after which the closure device 48 is fastened in the flow contour ring 46. By screwing with the rotor disks 22 at the same time a movement of the Strömungsungskonturrings 46 is excluded in the circumferential direction relative to the rotor disks 22 during operation of the turbomachine, which prevents wear on the Gleitkontaktflächen 54.

The screws need not necessarily be bolted to the rotor disks 22. Instead, it would be conceivable that the holes 56 of the flow contour ring 46 have an internal thread into which the screws are screwed to secure the closure device 48. In this case, the screws should be so long that their headless ends in the installed state can engage positively in the holes of the rotor disk, so as to ensure the fuse described above.

A second embodiment of a flow contour ring 46 shows FIG. 7 , where in FIG. 7 the edges of the flow contour ring 46 are shown in phantom and the closure device 48 arranged in its segment clearance 49 is shown as a solid line. The shutter 48 is such as is known from blades for circumferential grooves of blades.

The closure device 48 is configured in four parts with a left spacer 48a, a right spacer 48b and a middle spacer 48c, which are listed in the here Sequence in the segment clearance 49 can be used, with the left and right spacers arranged to interlock with undercuts 47 of the flow contour ring 46 can hook. In order to secure the closure device 48 against loss, a screw 55 with a trapezoidal beard 53 (FIG. FIG. 8 ) intended. On a front side of the central part 48 c, a spring 59 is also provided, which can engage in a corresponding groove which is provided on the shaft collar 23. Also, this present in the circumferential direction positive locking prevents relative movement of the flow contour ring 46 to the remaining rotor during operation of the turbomachine. Projections 57 ( FIG. 7 ) on the left and right spacers 48a, 48c also prevent relative movement of the spacers 48a, 48c with respect to the flow contour ring 46.

A second embodiment of a flow contour ring is shown in FIG FIG. 10 shown in perspective. In contrast to the first embodiment, the Strömungskonturring 46 shown here is designed rather sheet-like with a jacket plate 61, on which an inwardly projecting circumferential web 62 is provided, wherein web 62 and jacket plate 61 are connected to each other stabilizing over distributed along the circumference ribs 63. This flow contour ring 49 may also have sliding contact surfaces 54 distributed in opposite positions or evenly distributed on the inner circumference.

According to the in FIG. 10 selected representation, the flow contour ring 46 at its twelve o'clock position the segment clearance 49, which is open radially on both sides and the front side.

FIG. 11 shows one too FIG. 7 Similar representation of a closure device 48 for the second embodiment of the Strömungskonturrings 46. The closure device 48 according to the second embodiment shown here comprises an intermediate piece 66 and a cover member 68. The intermediate member 66 is via pins 70, which in correspondingly shaped Recesses 72 ( FIG. 10 ) of the Strömungskonturrings 46, whereby it is positively locked in the radial direction with the flow contour ring 46. At the same time, the cover element 68 is screwed by two screws 74 with the intermediate element 66. Since the cover element 68 bears laterally against the shaft collar 23, the pins 70 can not be released from the recesses 72 when the cover element 68 is mounted, so that the loss of the closure device 48 is reliably avoided.

The FIGS. 13 to 16 3 sequentially show the different steps of removing the last blade 26 of a blade ring using the flow contour ring 46 of the present invention FIG. 13 As can be seen, the circumferential position of the segment clearance 49 for removing the arranged in the right shaft collar 23 blade 26 is unsuitable, since this is to move according to the representation chosen here upwards, which FIG. 14 is shown with the arrow 76. Subsequently, the segment clearance 49 of the flow contour ring 46 is arranged so that the entire blade root of the blade 26 can be pushed into this. The displacement of the blade root of the blade 26 in the segment clearance 49 is in FIG. 15 shown, wherein the movement of the blade 26 is visualized by the arrow 78. Since the flow contour ring 46 is axially slightly wider than the shaft collar 23, the blade 26 can be inserted into the segment clearance 49 so far that the entanglement of the foot of the blade 26 with the retaining groove 24 is released. Subsequently, the blade 26 is the segment space 49 removed, which is in FIG. 16 is shown. The assembly of a blade on a rotor 21 naturally in reverse order.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be made by those skilled in the art without departing from the scope of the invention, which is defined by the following claims.

Claims (16)

1. Rotor for a turbomachine, having a flow path which is of ring-shaped cross section,
   having at least one endless shaft collar (23) in which there are provided at least partially axially extending holding grooves (24) with in each case one rotor blade (26) seated therein, forming a blade ring,
   characterized in that
   the rotor comprises at least one closed flow contour ring (46) with face-side side surfaces and with at least one radially outwardly pointing surface, in which there is provided at least one opening as an entrance to segment free spaces (49) provided in corresponding number,
   wherein the respective segment free spaces (49) are at least unilaterally open at the face sides,
   wherein the flow contour ring (46) is arranged to the side of the respective shaft collar (23) and its or their entrances are closed in each case by a closure device (48) fastened to the respective flow contour ring (46).
2. Rotor according to Claim 1,
   which has means for fastening a closure device (48) which closes off the entrance.
3. Rotor according to Claim 1 or 2,
   wherein the flow contour ring (46) is manufactured from metal or from glass-fibre-reinforced or carbon-fibre reinforced plastic.
4. Rotor according to Claim 1, 2 or 3,
   wherein the outwardly pointing surface of the flow contour ring (46) and/or that of the closure element (48) are/is coated.
5. Rotor according to one of the preceding claims,
   in which the respective entrance, the respective face-side opening and the respective segment free space (49) have such a size that at least one of the rotor blades (26) of the immediately adjacent ring can be mounted and dismounted through them.
6. Rotor according to one of the preceding claims,
   in which the flow contour ring (46) and the closure devices (48) thereof are designed so as to unilaterally block a displacement of the rotor blades (26) along their holding grooves (24).
7. Rotor according to one of the preceding claims,
   in which the closure device (48), formed in one piece, is screwed to the flow contour ring (46).
8. Rotor according to one of Claims 1-6,
   in which the closure device (48) is of multi-part form in the manner of a closure piece for circumferential grooves of rotor blade rings.
9. Rotor according to one of Claims 1-6,
   in which the closure device (48) comprises a cover element (68), which closes off the entrance in a flush manner, and an intermediate piece (66), wherein the intermediate piece (66) is seated in a radially positively locking manner in the flow contour ring (46) and is screwed to the cover element (68).
10. Rotor according to one of the preceding claims,
    in which the flow contour ring (46) has, radially at the inside, two to five sliding contact regions (54) with respect to the rest of the rotor.
11. Turbomachine having a ring-shaped flow path, having a rotor (21) according to one of Claims 1 to 10, wherein rings of guide blades (34) fastened to a rotationally fixed carrier, and the rotor blades (26) fastened to the rotor, are arranged alternately in succession along the flow path,
    wherein at least one of the guide blade rings comprises free-standing guide blades (34), and at least one of the two rotor blade rows immediately adjacent to said guide blade row comprises rotor blades (26) which are inserted in each case into at least partially axially extending holding grooves (24) of the rotor (21),
    characterized in that
    the one or more flow contour rings (46) of the rotor is or are situated opposite the tips of the free-standing guide blades (34).
12. Turbomachine according to Claim 11,
    in which the two respective rotor blade rings are provided on two axially immediately adjacent rotor base elements (25).
13. Turbomachine according to Claim 11 or 12,
    formed as a turbine.
14. Turbomachine according to Claim 11 or 12, formed as an axial compressor.
15. Static gas turbine having an axial compressor according to Claim 14.
16. Method for producing a rotor (21) for a turbomachine according to one of Claims 1 to 10, in which the rotor comprises multiple rotor base elements (25), and in which, before the directly adjacent rotor base elements (25) are placed against one another, the flow contour ring (46) is installed in between.

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