EP3587739A1 - Casing ring arrangement for a flow engine - Google Patents

Abstract

The invention relates to a casing ring arrangement (20) for a turbomachine (1), with a housing part (21), a casing ring segment (22), which is provided for this, in each case with respect to a longitudinal axis (2) of the turbomachine (1) To surround the rotor blade radially outward and for this purpose is arranged radially inside the housing part, and with a segment ring (25) which is divided all the way into segments (35, 36, 40) and with which the casing ring segment (22) is fastened to the housing part (21), wherein the segment ring (25) is arranged axially in a form-fitting manner on a form-locking element (26) of the housing part (21), for which purpose a respective segment (35, 36, 40) of the segment ring (25) is in each case assembled radially outward with the form-locking element (26), and wherein the segment ring (25) forms a support (27) on which the jacket ring segment (22) is supported with an axially front end supported radially inwards.

Description

Technical field

The present invention relates to a jacket ring arrangement for a turbomachine.

State of the art

The turbomachine can, for example, be a jet engine, e.g. B. a turbofan engine. The fluid machine is functionally divided into a compressor, combustion chamber and turbine. In the case of the jet engine, for example, the air drawn in is compressed by the compressor and burned in the downstream combustion chamber with added kerosene. The resulting hot gas, a mixture of combustion gas and air, flows through the downstream turbine and is expanded in the process. The turbine is typically subdivided into several modules, so it can have, for example, a high-pressure and a low-pressure turbine module. Each of the turbine modules then generally comprises a number of stages, each stage being composed of a guide vane ring and a rotor blade ring which follows downstream.

The jacket ring arrangement in question comprises a housing part and a jacket ring segment which is mounted radially on the inside of the housing part. In a fully assembled module, the casing ring segment delimits the gas channel radially outward, specifically at the axial height of a rotor blade ring. Accordingly, the jacket ring segment can be equipped, for example, with a sealing system or an inlet lining, along which the rotor blades of the ring graze with their outer cover bands. This should, such as. B. also the reference to a jet engine, illustrate the present subject, but initially not restrict it in its generality.

Presentation of the invention

The present invention is based on the technical problem of specifying a particularly advantageous casing ring arrangement.

This is achieved according to the invention with the jacket ring arrangement according to claim 1. Specifically, the object relates to the attachment or assembly of the jacket ring segment to the housing part, which is done with a segment ring. This segment ring is or is assembled from the radially inside with a positive locking element of the housing part. For this purpose, the segment ring is circumferentially divided into a plurality of segments, which are handled individually and can therefore be assembled one after the other from radially inside to radially outside with the form-locking element of the housing part. The fully assembled segment ring is held on the housing part in an axially positive manner.

The segment ring also forms a support on which the jacket ring segment is seated and is thus supported radially inwards. Compared to an alternative conceivable approach, namely a jacket ring segment that lies directly on a housing hook of the housing part itself, the approach according to the invention can initially be advantageous for thermal reasons. In particular, the shielding of the housing can be improved, and the support of the jacket ring segment can also be better sealed off from the gas channel. Furthermore, in the case of a solution with “housing hooks”, comparatively high thermal gradients would also occur on this or in the housing, which can limit the service life.

As an alternative to the present subject, the jacket ring segment itself could also bring a suspension element at its front end, which is positively mounted on the housing part instead of the segment ring. However, this can already be disadvantageous insofar as the jacket ring segment would have to be provided as a casting with a corresponding thickness in order to create a sufficiently stable suspension element. In the present case, however, the jacket ring segment can preferably be designed as a sheet metal part (see below), which offers cost and weight advantages. Due to the greater weight, a casting is also in its extension limited in the direction of circulation, there would be a larger number of impacts over the entire circulation (heating in the narrow gaps). Furthermore, a jacket ring segment with an integral suspension element is also comparatively complex and cost-intensive, which can be disadvantageous with regard to manufacture and also maintenance.

An inlet seal can be arranged on the casing ring segment, into which the rotor blades or outer sealing fins of the rotor blades can run.

Preferred refinements can be found in the dependent claims and the entire description, wherein the representation of the features does not always differentiate individually between device, method and use aspects; in any case, the disclosure is to be read implicitly with regard to all claim categories. In particular, it therefore always relates to both the casing ring arrangement and a module or turbine module with such, as well as corresponding uses.

In the context of this disclosure, “axially” generally relates to the longitudinal axis of the turbine module, and thus therefore the longitudinal axis of the turbomachine, which coincides, for example, with an axis of rotation of the rotors. "Radial" relates to the radial directions pointing away from it, and a "rotation" or "circumferential" or the "rotation direction" relates to the rotation about the longitudinal axis. "Front" and "rear" refer to the axial flow direction component of the hot gas, so this passes "front" parts axially in front of "rear" parts. In the context of this disclosure, "one" and "one" are to be read as indefinite articles without expressly stated otherwise and therefore always as "at least one" or "at least one".

The jacket ring segment is supported with its axially front end on the segment ring, with its axially rear end it preferably lies on the outer shroud of the following guide vane ring. In the course of the initial production, a module is usually assembled from axially front to axially rear, in the present case, for example, the segment ring can first be mounted on the housing part and the jacket ring segment can then be inserted. However, there is a particular advantage here in that assembly or disassembly from the front axially is also possible with the segmented segment ring. This can be particularly advantageous when overhauling the turbomachine, see below in detail.

The segment ring or its segments can be produced from a forged ring, for example, by turning and milling. The segments can also be cast parts (in connection with a reworking of the functional surfaces). Finally, additive manufacturing is also possible, ie the segment ring or segments can be built additively layer by layer from a previously formless or neutral material. When viewed in an axial section, the segment ring can, for example, form an inverted T-shape at its radially inner end. Its inner circumferential surface can preferably form a seal to an axially upstream gas channel component, for example, represent a piston ring running surface.

The assembled segment ring is held on the form-fitting element in an axially positive manner. For this purpose, the positive locking element of the housing part z. B. be a radially inward open groove in which the segment ring engages with a radially protruding web.

In a preferred embodiment, the arrangement is exactly the reverse, that is to say the form-locking element of the housing part is a web projecting radially inwards and seated in a receptacle of the segment ring which is open radially outwards. The individual segments of the segment ring are or are pushed radially outward onto the web of the housing part. Viewed in axial sections, the segments can each be U-shaped in a radially outer section, the U-shape is pushed onto the web.

In a preferred embodiment, the web of the housing part, viewed in an axial section, extends at an angle of at most 30 ° to the radial direction, with at most 20 ° or 10 ° being further preferred. The smaller of two angles is considered here, which includes a straight line in the axial section in the web with the radial direction. When viewed in the axial section, the web is preferably perpendicular to the longitudinal axis, so the angle is 0 °. This can be the design and also simplify the assembly, although in general an assembly from the inside is still possible even with an inclined web, as long as the assembly play and the elasticity of the segments can bridge undercuts (which result with increasing angle).

In a preferred embodiment, a securing ring is provided, on which the segments of the segment ring are supported in a radially inward manner. The locking ring presses the segments radially outward into contact with the form-locking element. For this purpose, the locking ring can extend uninterrupted in the circumferential direction. As an alternative to a retaining ring, a radial locking of the segments with or via a housing part is generally also conceivable, for example an axially upstream housing part could provide a corresponding fixation of the segments.

In a preferred embodiment, the retaining ring, which is closed all the way round (continuous without interruption), is pressed axially into a receptacle in the segment ring. With a view to the preferred ability to be assembled and disassembled from the front axially, the receptacle preferably faces the front axially, that is to say the retaining ring is pressed in axially to the rear. The retaining ring is held in the receptacle by a press fit.

In a preferred embodiment, the segment ring forms a radially protruding projection on the receptacle, behind which the retaining ring is held in an axially positive manner. This projection is preferably formed on an inner wall surface of the segment ring pointing radially inwards, against which the securing ring used rests with an outer wall surface. The projection is dimensioned such that the locking ring can be pressed in axially, but is then secured axially in the opposite direction. This is preferably supported by an inclined flank (sawtooth profile), along which the locking ring slides when pressed in.

In a preferred embodiment, the jacket ring segment is a sheet metal part, which can be advantageous, for example, in terms of costs (first production and also maintenance), but also in terms of weight. A seal can be attached radially on the inside of the sheet metal part be (e.g. soldered on), such as a so-called honeycomb seal. In general, however, a sheet metal part is not mandatory, and many of the advantages mentioned (for example, mountability "from the front") can also be achieved with a jacket ring segment produced as a cast part or generatively.

The embodiments described below relate to the orientation or extension of the abutting edges with which the segments of the segment ring adjoin one another in the circumferential direction. Two circumferentially next adjacent segments have mutually complementary abutting edges on a respective joint.

In a preferred embodiment, at least one of the segments has abutting edges that are parallel to one another when viewed in the axial direction. When assembling the segment ring, i.e. when the individual segments are inserted radially outwards one after the other, the segment with the mutually parallel abutting edges can also be pushed in or pushed on when the all-round neighboring segments are already arranged in their assembly position. The segment can be inserted along an insertion direction parallel to its abutting edges. In the direction of insertion, the segment is brought into its position in the segment ring. In relation to the segment ring as a whole, the mutually parallel abutting edges are preferably oriented such that they or their extensions towards the opposite side of the segment ring surround the center of the circle of the segment ring in the center.

In a preferred embodiment, every second segment has mutually parallel abutting edges in the circumferential direction. The segments with the abutting edges parallel to each other are preferably identical to one another and the complementary segments arranged between them are also identical to one another, so that the entire segment ring can be constructed with only two different segment types.

In another preferred embodiment, the segments are or are set up in such a way that the segment ring can ideally be constructed from only a single segment ring type. This can be achieved with a butt edge, which in Axial direction is oriented obliquely to the radial direction. Specifically, the oblique butt edge forms an angle α of at least 85 ° and at most 110 ° with a connecting line that extends diagonally through the segment to the outer corner of the oblique butt edge. Further preferred upper limits are at most 100 ° or 95 °, further preferred lower limits are (irrespective of this) at least 88 ° or 90 ° (in the order in which they are mentioned increasingly preferred). By appropriately limiting the angle α, the segment can also be used when the circumferentially next-adjacent segments are already arranged in their assembly position. The segment can first be brought into position with the opposite butt edge and then, as it were, turned into a system with the oblique butt edge, cf. Figure 4 for illustration.

In a preferred embodiment, all segments are identical to one another, that is to say rotationally symmetrical about the longitudinal axis. Keeping and assembling just one type of segment ring can simplify assembly and warehousing.

In a preferred embodiment, a sealing insert, preferably a sealing plate, is used on a joint where two segments adjoin one another with their abutting edges. For this purpose, a pocket open to the joint is provided in each of these two segments; the sealing insert is held axially therein and extends over the joint. So that these segments can still be assembled from the radially inside, one of the pockets is preferably open radially outwards. During assembly, the sealing insert is then placed in the other pocket, which is closed radially inwards and outwards, and when the other segment is positioned, it slides into the pocket, which is open radially outwards.

The invention also relates to a turbine module with a jacket ring arrangement disclosed herein. A rotor blade ring is arranged radially within the casing ring segment. The turbine module preferably has an axially downstream guide vane ring, on the outer shroud of which the jacket ring segment rests with its axially rear end (supported radially inward). The jacket ring arrangement with the jacket ring segment is preferably part of the axially foremost stage of the module because it is possible to remove it axially from the front. Of course, however, other or all stages of the turbine module can also be equipped with a jacket ring arrangement according to the invention.

The invention also relates to a method for overhauling a corresponding turbine module, the jacket ring segment being removed from the front axially by removing the segment ring. The individual modules (low pressure or high pressure etc.) of the turbine can be separated from one another comparatively easily, so that each module is accessible from the axially front and axially rear. Accessibility from the front axially can also be advantageous insofar as axially front components can be subjected to greater loads.

The invention also relates to the use of a corresponding turbine module or a jacket ring arrangement disclosed in a turbomachine, in particular in a jet engine, for example a jacket power engine.

Brief description of the drawings

The invention is explained in more detail below on the basis of an exemplary embodiment, the individual features within the framework of the subordinate claims also being essential to the invention in a different combination and furthermore not being distinguished in detail between the different claim categories.

Figur 1

ein Mantelstromtriebwerk in einem Axialschnitt;

Figur 2

eine erfindungsgemäße Mantelringanordnung als Teil des Mantelstromtriebwerks gemäß Figur 1 in einem Axialschnitt;

Figur 3

einen Ausschnitt eines Segmentrings der Anordnung gemäß Figur 2 in einem Schnitt senkrecht zur axialen Richtung;

Figur 4

als Alternative zu Figur 3 eine weitere Möglichkeit zur Orientierung der Stoßkanten der einzelnen Segmente.

In detail shows

Figure 1

a turbofan engine in an axial section;

Figure 2

a jacket ring arrangement according to the invention as part of the turbofan engine according to Figure 1 in an axial section;

Figure 3

a section of a segment ring according to the arrangement Figure 2 in a section perpendicular to the axial direction;

Figure 4

as an alternative to Figure 3 another way of orienting the abutting edges of the individual segments.

Preferred embodiment of the invention

Fig. 1 shows a turbomachine 1, specifically a turbofan engine, in an axial section. The flow machine 1 is functionally divided into a compressor 1a, a combustion chamber 1b and a turbine 1c. Both the compressor 1a and the turbine 1c are each made up of several stages, each stage being composed of a guide vane ring and a subsequent rotor blade ring. The rotor blades rotate during operation about the longitudinal axis 2 of the turbomachine 1. The air sucked in is compressed in the compressor 1a and then burned in the downstream combustion chamber 1b with added kerosene. The hot gas flows through the hot gas duct 3 and drives the rotor blades, which rotate about the longitudinal axis 2.

Fig. 2 shows a jacket ring arrangement 20, which is provided as part of a module of the turbine 1c. It has a housing part 21 and a jacket ring segment 22, on which a seal 23 is arranged radially on the inside, in the present case an inlet coating in the form of a honeycomb seal. The jacket ring segment 22 surrounds the blades 24 radially outward.

To mount the jacket ring segment 22 on the housing part 21, a segment ring 25 is provided, which is divided into a plurality of segments in the circumferential direction (cf. Fig. 3 and 4 ). The individual segments of the segment ring 25 are assembled from the inside radially with a form-locking element 26 of the housing part 21. The form-locking element 26 is provided in the present case as a radially inwardly projecting housing web onto which the segments of the segment ring 25 are pushed until the housing web finds a radial contact in a receptacle 25a of the segment ring 25. The segments of the segment ring are then also held in an axially positive manner. The segment ring 25 forms a support 27 which supports the jacket ring segment 22 radially inward at its axially front end. To hold the segments of the segment ring 25 radially in position, a locking ring 28 is used. This extends circumferentially without interruption and is pressed axially into a receptacle 29 of the segment ring 25. In the receptacle 29, it is held axially positively behind a projection 30.

A bore 31 is provided in the form-locking element 26 or the housing web of the housing part 21, which can be used (and is optional) for supplying a cooling fluid. Furthermore, the shielding plates 32 arranged radially between the housing part 21 and the casing ring segment 22 are optional; the approach according to the invention could also be realized with an insulating material or the like between the housing part 21 and the casing ring segment 22.

Fig. 3 shows the segment ring 25 in a section perpendicular to the longitudinal axis 2 (for the sake of clarity without hatching), namely a section of the segment ring with some segments 35, 36. The segments 35, 36 each have abutting edges 35a, 36a with which they adjoin one another. With the arrangement according to Fig. 3 the segment ring 25 is constructed from two types of segment rings. On the one hand there are the segments 35, the abutting edges 35a of each segment 35 are parallel to one another. These segments 35 and the complementary segments 36 follow one another alternately. Due to the mutually parallel abutting edges 35a, the segments 35 can each be pushed into their installation position in an insertion direction 37; the next neighboring segments 36 are brought into position beforehand.

Fig. 4 points to Fig. 3 alternative segments 40, with which the entire segment ring 25 can be constructed from a single segment ring type. For this purpose, a butt edge 40a is inclined in such a way that it forms an angle α of around 90 ° with a connecting line 41. The opposite abutting edge 40b is complementarily oblique, it forms an obtuse angle on an inner peripheral surface 42 of the segment ring and an acute angle on the outer peripheral surface 43. When inserting, a corresponding segment 40 can first be hooked in with the abutting edge 40b if the circumferentially next adjacent segments 40 are already in the assembly position. The segment 40 is then screwed into its assembly position.

Regardless of the design of the segments 35, 40 in detail, sealing inserts 46 are provided on the joints 45. <B> LIST OF REFERENCES </ b> flow machine 1 compressor 1a combustion chamber 1b turbine 1c longitudinal axis 2 Hot gas duct 3 Shroud assembly 20 housing part 21 Shroud segment 22 poetry 23 blade 24 segment ring 25 admission 25a Form-fitting element 26 edition 27 circlip 28 admission 29 head Start 30 drilling 31 shielding 32 segment 35 impact edge 35a segment 36 impact edge 36a segment 40 abutting edges 40a, b connecting line 41 Inner circumferential surface 42 Outer circumferential surface 43

Claims (15)

Sheath ring arrangement (20) for a turbomachine (1), with
a housing part (21),
a jacket ring segment (22) which, in each case with respect to a longitudinal axis (2) of the turbomachine (1), is provided for enclosing a rotor blade ring radially outwards and for this purpose is arranged radially inside the housing part, and
with a segment ring (25) which is subdivided into segments (35, 36, 40) and with which the jacket ring segment (22) is fastened to the housing part (21),
wherein the segment ring (25) is arranged axially in a form-fitting manner on a form-locking element (26) of the housing part (21), for which purpose a respective segment (35, 36, 40) of the segment ring (25) is assembled radially outward with the form-locking element (26) .
and wherein the segment ring (25) forms a support (27) on which the jacket ring segment (22) is supported with an axially front end supported radially inwards. Sheath ring arrangement (20) according to claim 1, wherein the form-locking element (26) of the housing part (21) is a radially inwardly projecting web which is arranged in a radially outwardly open receptacle (25a) of the segment ring (25). Sheath ring arrangement (20) according to claim 2, wherein the web extends in an axial section at an angle of at most 30 ° to the radial direction. Sheath ring arrangement (20) according to one of the preceding claims with a locking ring (28), of which the segments (35, 36, 40) of the segment ring (25) are pressed radially outward into abutment on the form-locking element (26). Sheath ring arrangement (20) according to claim 4, wherein the retaining ring (28), which is provided closed all round, is pressed axially into a receptacle (29) in the segment ring (25). Sheath ring arrangement (20) according to claim 5, in which the retaining ring (28), viewed in an axial section, is held axially positively in the receptacle (29) behind a projection (30). Jacket ring arrangement (20) according to one of the preceding claims, in which the jacket ring segment (22) is a sheet metal part and / or in which an inlet seal is arranged on the jacket ring segment. Sheath ring arrangement (20) according to one of the preceding claims, in which the segments (35, 36) of the segment ring adjoin each other circumferentially with abutting edges (35a, 36a), at least one (35) of the segments (35, 36) having abutting edges (35a), seen in the axial direction parallel to each other. A jacket ring arrangement (20) according to claim 8, in which the circumference of every second segment (35) has abutting edges (35a) which, viewed in the axial direction, lie parallel to one another. Sheath ring arrangement (20) according to one of Claims 1 to 7, in which the segments (40) of the segment ring (25) adjoin one another circumferentially with abutting edges (40a, b), at least one of the segments (40) having an oblique abutting edge (40a), seen in the axial direction with a connecting line (41) which is between an intersection of the oblique butt edge (40a) with an outer circumferential line (43) of the segment ring (25) and an intersection of the opposite butting edge (40b) with an inner circumferential line (42) of the segment ring (25) extends, an angle α, which is at least 85 ° and at most 110 °. Sheath ring arrangement (20) according to claim 10, in which all segments (40) of the segment ring are identical to one another. Sheath ring arrangement (20) according to one of the preceding claims, in which a sealing insert (46.) On a joint (45) at which two segments (35, 36, 40) adjoin one another with their abutting edges (35a, 36a, 40a, 40b) ) is arranged. Turbine module with a casing ring arrangement (20) according to one of the preceding claims and with a rotor blade ring which the casing ring segment (22) surrounds radially outwards, the casing ring arrangement (20) and thus the segment ring (25) preferably being part of an axially front step of the turbine module are. Method for overhauling a turbine module according to Claim 13, in which the casing ring segment (22) is removed from the front axially by removing the segment ring (25). Use of a jacket ring arrangement (20) according to one of claims 1 to 11 or a turbine module according to claim 12 or 13 in a turbomachine (1), in particular in a jet engine.

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