The present invention relates to a module for a turbomachine.
The turbomachine may involve, for example, a jet engine, e.g., a turbofan engine. Functionally, turbomachines are divided into compressors, combustion chambers, and turbines. Generally, in the case of the jet engine, aspirated air is compressed by the compressor and burned in the downstream combustion chamber with fuel mixed in. The hot gas that arises, a mixture of combustion gases and air, flows through the downstream turbine and is thereby expanded. In this case, the turbine withdraws the hot gas, proportionally also as energy, in order to drive the compressor. The turbine and the compressor are usually each constructed with multiple stages, wherein, in each case, a stage has a ring of guide vanes and a ring of rotating blades. In the case of the compressor, the rotating blade ring is arranged each time downstream of the guide vane ring.
The present invention has as a subject a module comprising a guide vane arrangement and a seal carrier. In addition to the one or more guide vanes arranged on an inner platform, the guide vane arrangement has guide pins that are arranged radially opposite the guide vanes inside on the inner platform. The one or more guide pins form a so-called spoke centering and, for this purpose, engage in an uptake that opens radially outward for the seal carrier. Further, a slide body is arranged in this uptake, this slide body forming a contact for the one or more guide pins relative to the direction of rotation. In the direction of rotation, which refers to a rotation around the longitudinal axis of the module or of the turbomachine, considerable mechanical forces are transferred by way of the guide vanes, and the slide body is stressed correspondingly. Therefore, currently, a special slide body that withstands these high mechanical stresses is used and is fastened with a rivet.
The present invention is based on the technical problem of providing a particularly advantageous module for a turbomachine.
This problem is solved according to the invention by a module of the present invention, in which the slide body is designed in one piece with a wall of the seal carrier that axially bounds the uptake with the guide pin therein. The one-piece configuration is advantageous in this regard, since the slide body need not be fastened separately as an integral part; in concrete terms, no riveting is required. In the prior art, the slide body is placed between two walls of the seal carrier that together axially bound the uptake and is fastened by a rivet that penetrates through these walls and the slide body. In this case, the slide body needs to be somewhat under-dimensioned, so that it can generally be moved between the walls into the mounting position. In the riveting itself, the walls are pressed together prior to closing the rivet. The inventor has now determined that the rivet is loaded with a pre-stress thereby, which is based on the spring effect after the riveting tool has been removed, and this pre-stress can lead, in the worst case, to a failure of the rivet, initially or over the period of use. This cleaving problem can be resolved by the one-piece configuration.
Preferred embodiments are found in the dependent claims and the overall disclosure, wherein, in the presentation of the features, a distinction is not always made individually between the module, a corresponding compressor, or the turbomachine. The disclosure is to be read with respect to all of these categories, in particular also to corresponding applications.
As is clear in the details that follow, the uptake is usually axially bounded by two walls of the seal carrier, which form a U profile in an axial section. With respect to the radial depth of this U profile, the slide body is arranged essentially in the center according to the prior art; thus, a free space remains radially between the slide body and the base of the profile. As the example of embodiment also illustrates, the slide body extends in the present case, in contrast, preferably down to the base of the profile. If, for example, the uptake is introduced from radially outside in a material-removing manner, e.g., by milling or piercing, an appropriate shape may also be necessary. A material removal is then hardly possible radially underneath the slide body due to the lack of accessibility. In comparison to the prior art with the free space therein, a certain disadvantage must therefore be taken into the bargain, that is, a heavier weight as a consequence of the larger volume of the slide body. Although this may translate into a somewhat increased fuel consumption, for example, in the case of an aircraft engine, considered overall, the increased reliability with the subject of the invention is more important.
In general, in the scope of this disclosure, “axial” refers to the longitudinal axis of the module, thus the longitudinal axis of the compressor or of the turbomachine. This longitudinal axis can coincide, for example, with an axis of rotation, in order to rotate the rotating blades associated with the guide vane arrangement during operation. “Radial” relates to the radial directions perpendicular thereto, pointing away from the longitudinal axis, and “rotation” or the “direction of rotation” refers to a rotation around the longitudinal axis. In the case of an “axial section”, the longitudinal axis lies in the sectional plane.
Further, in the scope of this disclosure, unless expressly indicated otherwise, “a” and “one” are to be read as the indefinite article and thus also are always to be read as “at least one”. The guide vane arrangement can be provided, for example, as a multiple arrangement; thus, a plurality of guide vanes can be arranged radially outside on the inner platform and follow one another circumferentially. The guide vane arrangement forms the stage jointly with another or other guide vane arrangement(s) that follow one another circumferentially. Preferably, all guide vane arrangements of the stage are guided on a slide body formed in one piece with the wall of the seal carrier.
As a consequence of the configuration “in one piece” with one another, the slide body and the seal carrier wall cannot be separated from one another in a non-destructive manner; therefore, they can only be separated from one another with at least partial destruction of the slide body and/or the seal carrier wall or a connecting layer therebetween. In general, a one-piece formation is also conceivable by a material-bonded or cohesive connection of the slide body with the seal carrier wall, in particular, by a welding, e.g., by friction welding.
In the preferred embodiment, the slide body is designed monolithically with the seal carrier wall. The two are thus shaped together, for example, in the same manufacturing process, e.g., in a casting process or in an additive construction. The slide body and the seal carrier wall, however, can also be worked out of a solid material by corresponding removal of material, e.g., by milling or piercing, etc. A transition region between slide body and seal carrier wall can be free of boundaries between different materials or materials of different manufacturing history as a consequence of the “monolithic” embodiment. The monolithic embodiment can be particularly robust, for example.
In a preferred embodiment, at least one surface region of the slide body that forms the contact for the guide pins is provided with a coating. Although the slide body is not provided from a material that is more solid when compared with the seal carrier wall, unlike the case in the prior art, the mechanical strength can be advantageously increased with the coating.
In a preferred embodiment, an inner wall surface of the seal carrier wall is provided with a coating, at least in a region around the slide body, which can help increase the strength or capacity to withstand load in this mechanically stressed region. The inner wall surface delimits the uptake axially. Preferably, the slide body itself and the inner wall surface are coated in regions. That is, if, in the case of the material-removing manufacture, the slide body with a fillet can transition into the inner wall surface, said surface is then preferably coated.
A highly heat-resistant nickel alloy is provided as a coating in a preferred embodiment. Copper can be alloyed to the nickel, for example.
In a preferred embodiment, the first guide pin, together with a second guide pin, engage the slide body with respect to the direction of rotation. The slide body is thus held circumferentially between the guide pins (however, a piece can still be displaced far radially), for which reason, this arrangement is also called Tang (“forceps”). The two guide pins find their respective contact on lateral surfaces of the slide body that are circumferentially opposite one another; this arrangement represents a spoke centering.
In a preferred embodiment, as already mentioned, the seal carrier wall forms a U profile with another seal carrier wall, when considered in an axial section. The seal carrier walls, which are also called partition walls, have a radial surface extent, in the direction of rotation; their respective thickness dimension is taken axially. Preferably, the seal carrier walls lie parallel to one another and each is perpendicular to the longitudinal axis (with respect to their surface extent).
In a preferred embodiment, the slide body is formed in one piece with both seal carrier walls, preferably monolithic in each case. However, this is not absolutely necessary in general: the slide body could also be provided in one piece only with one of the seal carrier walls; the other seal carrier wall could then be produced as a metal sheet, for example. The one-piece/monolithic construction, preferably with both seal carrier walls, can be obtained, for example, in the case of a material-removing manufacture, starting from a disk: from radially outside, from the edge of the disk, an axially central region will be removed, whereby the uptake is formed and the seal carrier walls remain. In this case, the slide body also remains; therefore, no material is removed in the corresponding region.
In a preferred embodiment, the slide body extends radially inward, down to the base of the U profile; see also the above remarks. A correspondingly lengthwise extended slide body can also be advantageous with respect to mechanical stress, since a force that is introduced from the one or more guide pins and that is distributed onto a larger surface means a lower pressure and thus less stress.
In the case of one preferred embodiment, a rivet passes through the two walls and the slide body. On an outer wall surface, which is turned away from the uptake, of at least one of the two seal carrier walls, preferably on both seal carrier walls, the rivet holds a seal (on the outer wall surface in each case). The rivet thus serves for fastening the seal, not for fastening the slide body, for which reason the initially described cleavage problem does not occur, or at least does not occur to that extent.
In a preferred embodiment, the seal is a fish mouth seal. Said seal can be formed, in particular, from S-shaped or L-shaped sheet metal parts that extend out away from the respective outer wall surface of the corresponding seal carrier wall with an axial extent, at least proportionally. The fish mouth seals may thus have a radial overlap with axial flanges of the upstream or downstream rotating blade arrangements.
In the case of a preferred embodiment, the seal carrier bears a sealing element, preferably a honeycomb seal, radially inside. The arrangement of seal carrier ring, fish mouth seal, and spoke centering by the slide body is also called Static Inner Air Seal (SIAS).
The invention also relates to a compressor having a module as disclosed in the present document. Further, the invention also relates to a turbomachine having a corresponding compressor or a presently described module.
The invention will be explained in more detail in the following on the basis of an example of embodiment, wherein the individual features in the scope of the independent claims can also be essential to the invention in another combination, and wherein also no distinction is made individually between the different claim categories.
Taken individually,
The guide pins 21c,d are held in position axially between the walls 23a,b; in this case, however, they can still move radially and thus are not clamped. In further detail, the sectional plane of the axial section according to
The guide pins 21c,d are not shown in
Based on the one-piece or monolithic configuration, the slide body 31 does not need to be fastened with a rivet, which, in the present assembly, would produce a rivet loaded with a high pre-stress. According to the prior art, namely, a certain axial gap is necessary between the slide body 31 and the walls 23a,b; see also the remarks in further detail in the introduction to the description. The embodiment according to the invention can thus have advantages with respect to service life and reliability.
As can be seen from a juxtaposition of
It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be covered by the appended claims.
Number | Date | Country | Kind |
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10 2017 221 660.3 | Dec 2017 | DE | national |