ROTOR FOR A FLOW MACHINE AND FLOW MACHINE WITH SUCH A ROTOR

Description

[0001] The invention relates to a rotor for a turbomachine and to a turbomachine with such a rotor.

[0002] Rotors of turbomachinery, such as stationary gas turbines and aircraft engines, are known in many variations from the prior art. It is also known to equip a rotor arm or rotor body with one or more sealing fins. A sealing fin projects radially from the rotor body with respect to an axis of rotation and, during rotor operation, interacts with an associated sealing element, which is stationary with respect to a housing of the turbomachine, to prevent unwanted leakage. Rotor sealing fins are also typically designed with or on a base or pedestal. Such a base can serve as a support for covers during the coating of the sealing fins. A large axial overhang of the base is necessary to avoid partial coating of the rotor arm, which could lead to structural mechanical disadvantages.For this purpose, such a base has, with respect to an axial direction of the rotor, a base area located upstream of the sealing fin in the installation position of the rotor and a base area located downstream of the sealing fin.

[0003] The axial base width of the base areas located to the left and right of the sealing fin, viewed axially, cannot be arbitrarily increased, as axial and radial relative displacements between the sealing fin and the sealing element can occur during operation of the associated turbomachine. If this is not adequately addressed, axial contact between the base and the sealing element can occur, for example, in compressor pumps. Such contact is unacceptable, as it could lead to damage. Axially narrower bases, in which contact between the base and the sealing element is reliably prevented under all operating conditions of the associated turbomachine, often have an insufficient axial contact area for covers when coating, for example, the sealing fin.This can unintentionally coat areas on the base or rotor arm, which then need to be reworked, stripped, or recoated.

[0004] Related prior art is disclosed in US 2005 / 150234 A1, EP 3 293 360 A1, US 2008 / 124215 A1 and US 2009 / 067997 A1. EP 3 312 388 A1 discloses the preamble of claim 1.

[0005] The object of the present invention is to provide a rotor which, on the one hand, enables reliable coating coverage and, on the other hand, can also meet the axial and radial clearance requirements of an associated turbomachine under all operating conditions. A further object of the invention is to provide a turbomachine which can meet the axial and radial clearance requirements between its rotor and an associated sealing carrier under all operating conditions.

[0006] The problems are solved according to the invention by a rotor with the features of claim 1 and by a turbomachine according to claim 8. Advantageous embodiments with expedient further developments of the invention are specified in the respective dependent claims, wherein advantageous embodiments of the rotor are to be regarded as advantageous embodiments of the turbomachine and vice versa.

[0007] A first aspect of the invention relates to a rotor for a turbomachine, in particular for an aircraft engine, with a rotor body on which at least one sealing fin is arranged on a base for interaction with an associated sealing element of the turbomachine, wherein the base has, with respect to an axial direction of the rotor, a base region adjacent upstream of the sealing fin and a base region adjacent downstream of the sealing fin, the base regions extending substantially parallel to the axial direction. According to the invention, the upstream base region and the downstream base region have different radial distances to a radially outer sealing tip of the sealing fin. In other words, the base of the sealing fin is not designed symmetrically, but asymmetrically, in that the base regions are located to the left (upstream) and to the right (downstream).Downstream of the sealing fin, the base exhibits different radial heights and thus different distances to the sealing tip. This ensures reliable coating coverage and allows the axial and radial clearance requirements of the associated turbomachine to be met under all operating conditions. This is because the radial staggering of the base prevents contact between any of the base areas and the corresponding sealing element of the turbomachine's sealing carrier. This fulfills both the structural-mechanical requirements (no contact at all operating points) and the manufacturing requirements (sufficient axial contact of the coating). Furthermore, the improved coating properties result in a lower rework rate, leading to corresponding time and cost savings.The radial staggering of the base also allows the use of one or more stepped sealing elements, enabling smaller axial designs and thus improving the efficiency and surge line of an associated turbomachine. It should be noted that the terms "axial," "radial," and "circumferential" always refer to the machine or rotation axis of the rotor when installed in the turbomachine, unless the context implicitly or explicitly indicates otherwise. In general, "a" or "an" within this disclosure is to be read as an indefinite article, meaning that unless explicitly stated otherwise, it always also means "at least one." Conversely, "a" or "an" can also be understood as "only one."

[0008] In an advantageous embodiment of the invention, it is provided that the ratio between the radial distance of the upstream adjacent base area and the radial distance of the downstream adjacent base area is between 0.25 and 4, wherein the ratio cannot be 1. In other words, it is intended that A1:A2 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 3.05, 3.10, 3.15, 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3.50, 3.55, 3.60, 3.65, 3.70, 3.75, 3.80, 3.85, 3.90, 3.95, or 4.00, where A1 is the radial distance or radial height of the upstream adjacent base area. and A2 the radial distance or.The radial height of the downstream adjacent base area is defined, and all intermediate values ​​except 1.0 (A1=A2) are considered to be implicitly disclosed. This allows the specific requirements of the rotor and its associated turbomachine to be optimally considered.

[0009] In a further embodiment of the invention, it has proven advantageous for the rotor to be designed as a compressor rotor and for the upstream base area to have a greater distance to the radially outer sealing tip of the sealing fin than the downstream base area. Alternatively, the rotor is designed as a turbine rotor and for the upstream base area to have a smaller distance to the radially outer sealing tip of the sealing fin than the downstream base area. This allows the different flow conditions in a compressor and in a turbine to be optimally accommodated.

[0010] Further advantages arise from the fact that the upstream and downstream adjacent base areas have different axial extents. In other words, it is intended that not only the radial height of the base areas to the left and right, or upstream and downstream of the sealing fin, can differ, but also their axial extents or widths. In particular, a combination of different radial and different axial extents has proven especially advantageous. The axial extent is measured from an adjacent sealing fin wall to a respective edge of the base area in question. This allows for particularly short axial rotor designs with corresponding improvements in the efficiency and surge line of the associated turbomachine.

[0011] In a further advantageous embodiment of the invention, the rotor is designed as a compressor rotor and the upstream base region has a smaller axial extent than the downstream base region, or the rotor is designed as a turbine rotor and the upstream base region has a larger axial extent than the downstream base region. This allows the different flow conditions in a compressor and in a turbine to be optimally accommodated.

[0012] Further advantages arise from the sealing fin having an asymmetrical sealing tip in cross-section and / or a coated sealing tip. This allows the sealing effect of the sealing fin to be optimally adapted to the respective application situation.

[0013] In a further advantageous embodiment of the invention, the rotor body has at least two sealing fins arranged one behind the other in the flow direction, preferably having different radial distances to an axial axis of rotation of the rotor. This allows the at least two sealing fins to interact with radially stepped sealing elements, resulting in a particularly good seal and a correspondingly improved reduction in leakage.

[0014] A second aspect of the invention relates to a turbomachine, in particular an aircraft engine, which, according to the invention, comprises at least one rotor according to the first aspect of the invention, the at least one of whose sealing fins interacts with at least one associated sealing element. This allows the axial and radial clearance requirements between the rotor and the associated sealing element to be met under all operating conditions of the turbomachine. Various seals are suitable as sealing elements, for example, honeycomb seals. Alternatively, a brush seal can also be used as a sealing element. Further features and their advantages can be found in the descriptions of the first aspect of the invention, whereby advantageous embodiments of the first aspect of the invention are to be considered advantageous embodiments of the second aspect of the invention and vice versa.

[0015] In an advantageous embodiment of the invention, the at least one sealing element of the turbomachine is held by a seal carrier. This allows for particularly simple and reliable assembly as well as correspondingly simple replacement of the at least one sealing element. The seal carrier can be formed as a single-piece ring or in multiple parts from several ring segments, which are then assembled to form a ring or ring similar to the guide vane ring. For mounting on a housing or a guide vane or guide vane ring, the seal carrier can have a connection area at its radially outer end, while an arrangement area for mounting the sealing element is provided at its radially inner end.

[0016] Further advantages arise from the fact that the at least one sealing element comprises an inlet seal, in particular a honeycomb seal. The inlet seal serves to form a sealing gap between the sealing tip of the at least one sealing fin and the static part of the turbomachine in order to reduce leakage of a flow medium. A honeycomb seal can optionally be deposited directly in the area of ​​the seal carrier or on another machine part.

[0017] In a further advantageous embodiment of the invention, the rotor has at least two sealing fins arranged on a base in the axial direction, which interact with respective sealing elements arranged radially in a stepped configuration relative to one another. Such a radially stepped sealing arrangement allows for a particularly high reduction in leakage and thus increases the efficiency and the surge line of the turbomachine. Each base can be designed asymmetrically in the manner described above. Alternatively, only some or only one of the bases can be designed asymmetrically in the manner described above, while the other base(s) are designed symmetrically.

[0018] In a further advantageous embodiment of the invention, the at least one sealing element is held on a housing of the turbomachine and / or on at least one guide vane, in particular on a guide vane ring. This allows for a particularly good sealing of a flow path of the turbomachine via an internal seal (Inner Air Seal, IAS).

[0019] Further features of the invention are evident from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as those subsequently mentioned in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations without departing from the scope of the invention. Thus, embodiments that are not explicitly shown and explained in the figures, but which can be derived and generated from the explained embodiments by separate combinations of features, are also to be considered as encompassed and disclosed by the invention. Embodiments and combinations of features that do not exhibit all the features of an originally formulated independent claim are also to be considered disclosed.Furthermore, embodiments and combinations of features, in particular those set out above, are to be considered disclosed which go beyond or deviate from the combinations of features set out in the cross-references of the claims. This shows: . Fig. 1 a schematic axial sectional view of a rotor according to the invention; Fig. 2 a schematic axial sectional view of the rotor in the area of ​​a sealing fin cooperating with a sealing element of a turbomachine; Fig. 3 a schematic axial sectional view of the rotor according to the invention in the cold assembly state; and Fig. 4 a schematic axial sectional view of the rotor according to the invention in two possible operating states of the associated turbomachine.

[0020] Fig. 1 Figure 1 shows a schematic axial sectional view of a rotor 10 of an aircraft engine according to the invention. The rotor 10, which in this case is designed as a compressor rotor and rotates about an axis of rotation D in the installed state, comprises a rotor body 12 which carries three circumferential sealing fins 14. Each sealing fin 14 is arranged on a base 16. The bases 16 can also be referred to as pedestals. It can be seen that each base 16, with respect to a flow direction S of an operating fluid of the associated flow direction, has a base region 16a located upstream of its sealing fin 14 and a base region 16b located downstream of the sealing fin 14. In the present embodiment, it can be seen that the downstream base 16 is asymmetrically designed, such that its upstream base region 16a and its downstream base region 16b have different radial distances to the sealing tip 18 of the respective sealing fin 14.A reverse configuration is also conceivable, for example in turbines. The first two bases 16, viewed in the flow direction S, are symmetrically designed, such that their upstream base regions 16a and their downstream base regions 16b each have the same radial distance to the respective sealing tip 18. Additionally, the base regions 16a, 16b of the first two bases 16 are also of equal width and have the same axial overhang extending from the sealing fin 14. Alternatively, it is possible that one of the more upstream bases 16 is asymmetrically designed with respect to its radial and, if applicable, axial shape, or that several or all bases 16 are asymmetrically designed with respect to their radial and, if applicable, axial shape. Likewise, more or fewer bases 16 and, correspondingly, more or fewer sealing fins 14 can be provided.

[0021] Fig. 2 Figure 1 shows a schematic axial sectional view of the rotor 10 in its installed state in the region of the downstream sealing fin 14, which interacts with an associated sealing element 20 of the turbomachine. The sealing element 20 is designed as a honeycomb seal and is held by a seal carrier 22 on a guide vane (not shown) of a compressor stage of the turbomachine. It can be seen that the seal carrier 22 is designed as a stepped labyrinth seal of an inner air seal (IAS), such that the upstream sealing element 20 has a smaller radial distance to the axis of rotation D of the rotor than the downstream sealing element 20. Furthermore, it can be seen that the sealing tips 18 of all sealing fins 14 have an asymmetrical cross-section and are provided with a coating 24, which can also be referred to as tip armoring.In the illustrated embodiment, the ratio of the left radial height A1 of the upstream base area 16a to the right radial height A2 of the downstream base area 16b is approximately A1:A2 = 1.5, although other ratios are also possible. The overhangs or axial widths of the base areas 16a and 16b can be the same or different. Due to the desired axially short design of a compressor stage and the radially stepped labyrinth seal for improved leakage reduction, the axial sealing fin positions on the rotor body 12 are defined, and the overhang of the individual bases 16 is limited. The axial overhangs of the bases 16 are necessary for adequate masking during the coating process of the sealing tips 18. An excessively short width of the base areas 16a and 16b can lead to the lifting of sealing lips used for masking in coating or spraying processes.The possible consequence of such a detachment is the injection molding and the undesirable coating of the base flanks or the rotor base body 12. This is inadmissible for structural mechanical reasons.

[0022] Fig. 3 Figure 1 shows a schematic axial sectional view of the rotor 10 according to the invention in its cold assembly state and is subsequently discussed in conjunction with Fig. 4 This section explains the invention and shows a schematic axial sectional view of the rotor 10 according to the invention in two possible operating states of the associated turbomachine. The position of the sealing element 20 or the seal carrier 22 shown with dotted lines corresponds to the cold assembly state, while the position shown with solid lines corresponds to the so-called compressor pumping state. The basic structure of the rotor 10 can be found in the preceding description. At certain operating points of the turbomachine, for example during the so-called compressor pumping state, there is a risk of axial contact between the left or upstream base region 16a of a base 16 and a sealing element 20 of the inner ring seal carrier 22. This contact is unacceptable, so the bases 16 would have to be designed to be correspondingly narrower.This, in turn, would reduce the contact area for a coating cover and entail the risk of impermissible coatings. An alternative axial displacement of the sealing position is also generally not possible due to the stepped design or the necessary axial overhangs of the sealing elements 20. These two problems can be overcome with the aid of the radial stepped design of at least one base 16 according to the invention. As can be seen particularly in area IV in . Fig. 4As can be seen, even a significant relative displacement of the sealing elements 20 with respect to the rotor 10 does not lead to a collision between the sealing element 20 and the left or upstream base area 16a of the rear base 16. Thanks to the design proposed in the invention, with its reduced radial height on one side of the base 16, the necessary axial width of both base sides 16a, 16b can still be maintained without radial or axial contact between the base 16 and the honeycomb 20. The individually required radial distance between the sealing tip 18 and the base areas 16a, 16b is achieved in a clearance-gap design for all operating points. This allows for improved manufacturability of the sealing fin coating 24 with a lower rework rate, which leads to a reduction in manufacturing costs. The radial stepping of at least one base 16 facilitates or...This allows the use of stepped sealing elements 20 in small compressor sizes, as a smaller axial design is possible. This leads to an improvement in the efficiency and the surge line of the correspondingly equipped turbomachine. Reference symbol list:

[0023] 10 Rotor 12 Rotor base 14 Sealing fin 16 Base 16a Base area 16b Base area 18 Sealing tip 20 Sealing element 22 Seal carrier 24 Coating D Axis of rotation S Flow direction A1 Spacing A2 Spacing

Claims

1. Rotor (10) for a turbomachine, in particular for an aircraft engine, comprising a rotor main body (12) on which at least one sealing fin (14) arranged on a base (16) is arranged to interact with a corresponding sealing element (20) of the turbomachine, wherein the base (16) has, with respect to an axial direction of the rotor (10) for the support of covers in the sealing fin coating, a base region (16a) adjacent to and upstream of the sealing fin (14) and a base region (16b) adjacent to and downstream of the sealing fin (14), wherein the base regions (16a, 16b) extend substantially in parallel with the axial direction, characterized in that the upstream adjacent base region (16a) and the downstream adjacent base region (16b) have different radial distances (A1, A2) to a radially outer sealing tip (18) of the sealing fin (14).

2. Rotor (10) according to claim 1, characterized in that a ratio between the radial distance (A1) of the upstream adjacent base region (16a) and the radial distance (A2) of the downstream adjacent base region (16b) is between 0.25 and 4, wherein the ratio is not 1.

3. Rotor (10) according to claim 1 or claim 2, characterized in that the rotor (10) is designed as a compressor rotor and the upstream adjacent base region (16a) has a greater distance (A1) to the radially outer sealing tip (18) of the sealing fin (14) than the downstream adjacent base region (16b) or in that the rotor (10) is designed as a turbine rotor and the upstream adjacent base region (16a) has a smaller distance (A1) to the radially outer sealing tip (18) of the sealing fin (14) than the downstream adjacent base region (16b).

4. Rotor (10) according to any of claims 1 to 3, characterized in that the upstream adjacent base region (16a) and the downstream adjacent base region (16b) have different axial extents.

5. Rotor (10) according to any of claims 1 to 4, characterized in that the rotor (10) is designed as a compressor rotor and the upstream adjacent base region (16a) has a smaller axial extent than the downstream adjacent base region (16b), or in that the rotor (10) is designed as a turbine rotor and the upstream adjacent base region (16a) has a larger axial extent than the downstream adjacent base region (16b).

6. Rotor (10) according to any of claims 1 to 5, characterized in that the sealing fin (14) has a sealing tip (18) which is asymmetrical in cross section and / or a sealing tip (18) which is provided with a coating (24).

7. Rotor according to any of claims 1 to 6, characterized in that, in the axial direction, the rotor main body has at least two sealing fins arranged one behind the other in the direction of flow, which sealing fins preferably have different radial distances to an axial rotation axis of the rotor.

8. Turbomachine, in particular an aircraft engine, comprising at least one rotor (10) according to any of claims 1 to 7, the at least one sealing fin (16) of which interacts with at least one corresponding sealing element (20).

9. Turbomachine according to claim 8, characterized in that the at least one sealing element (20) of the turbomachine is held by a seal carrier (22).

10. Turbomachine according to claim 9, characterized in that the at least one sealing element (20) comprises an inlet seal, in particular a honeycomb seal.

11. Turbomachine according to any of claims 8 to 10, characterized in that, in the axial direction, the rotor (10) has at least two sealing fins (14) which are each arranged on a base (16), which sealing fins interact with respective sealing elements (20) which are arranged radially stepped relative to one another.

12. Turbomachine according to any of claims 8 to 11, characterized in that the at least one sealing element (20) is held on a housing of the turbomachine and / or on at least one guide vane, in particular on a guide vane ring.