ROTOR ARRANGEMENT FOR A GAS TURBINE WITH INCLINED AXIAL CONTACT SURFACES FORMED ON ROTOR SEGMENTS, GAS TURBINE AND AIRCRAFT GAS TURBINE

Description

[0001] The present invention relates to a rotor arrangement for a gas turbine, in particular an aircraft gas turbine, having a plurality of rotor segments arranged one after the other in the axial direction, which are connected to one another in the axial direction by at least one tie rod device, wherein a rotor segment which is at the front in the axial direction has a first contact surface and a rotor segment which is at the rear in the axial direction has a second contact surface, wherein the first contact surface and the second contact surface are at least partially in contact with one another, and wherein the first contact surface and the second contact surface are substantially annular and extend in the radial direction and the circumferential direction.

[0002] Directional terms such as "axial", "radial" and "circumferential" are generally to be understood as referring to the machine axis of the gas turbine, unless the context explicitly or implicitly indicates otherwise.

[0003] In such rotor arrangements, particularly during gas turbine operation, high thermal and mechanical influences in the area of ​​the axially adjacent contact surfaces cause large axial stresses on two adjacent rotor segments, which are part of an axially clamped tie-rod assembly with multiple rotor segments. It has been shown that, due to high loads in the tie-rod assembly, annular and, in particular, thin, force transmission zones are created in particular, which are very limited in the radial direction and in which pronounced axial force peaks are transmitted, leading to the aforementioned high and undesirable stresses. In such highly loaded force transmission areas, there is an increased risk of wear; in particular, material fretting can occur.

[0004] US 20100290904 A1 discloses a rotor arrangement with wedge-shaped contact surfaces. For general technical background, reference is made to the following documents, for example: US 8,459,943 B2, US 8,794,923 B2, US 2011 / 0219781 A1 and US 2020 / 0291781 A1, EP 2677120A, US 20070009360 A1, and WO 2014039826A1.

[0005] The object underlying the invention is to provide a rotor arrangement in which the above disadvantages can be avoided.

[0006] To solve this problem, a rotor assembly and a gas turbine having the features of the respective independent patent claims are proposed. Advantageous and optional embodiments are contained in the dependent claims.

[0007] What is proposed is a rotor arrangement for a gas turbine, in particular an aircraft gas turbine, comprising a plurality of rotor segments arranged one after the other in the axial direction and connected to one another in the axial direction by at least one tie rod device; wherein a rotor segment at the front in the axial direction has a first contact surface and a rotor segment at the rear in the axial direction has a second contact surface, wherein the first contact surface and the second contact surface are at least partially in contact with one another, and wherein the first contact surface and the second contact surface are substantially annular and extend in the radial direction and the circumferential direction.It is provided that the first contact surface and / or the second contact surface extend at least partially inclined with respect to the radial direction, wherein an angle is formed between the first contact surface and the second contact surface with respect to a sectional plane spanned by the axial direction and the radial direction.

[0008] By designing the contact surfaces of axially adjacent rotor segments in this way, the ring-like contact or force transmission area described above as disadvantageous can be avoided. This allows the transmission of axial forces to be better distributed across the entire contact surface, preventing undesirable stress peaks.

[0009] In the rotor arrangement, the first contact surface can be substantially parallel to the radial direction, and the second contact surface can be inclined to the radial direction. However, the reverse configuration is also conceivable, whereby the second contact surface can be substantially parallel to the radial direction, and the first contact surface can be inclined to the radial direction.

[0010] In the rotor arrangement, the front rotor segment may be a rotor blade ring and the rear rotor segment may be a seal carrier.

[0011] In the rotor arrangement, the angle between the first contact surface and the second contact surface can be 0.5° to 3°, in particular 0.8° to 1.2°. The inclination or angle can be selected depending on the remaining geometry of the adjacent rotor segments or their contact surfaces. It is also conceivable that sections with different opening angles may arise along the radial direction between the two contact surfaces. For example, the opening angle may increase from radially inward to radially outward.

[0012] According to the invention, the front rotor segment and the rear rotor segment are clamped together via a single contact surface pair consisting of the first annular contact surface and the second annular contact surface. Such a design avoids over-determination in the system, such as would occur with a wedge-shaped connection. Preferably, the first contact surface and the second contact surface can each be designed as flat annular surfaces.

[0013] According to a further preferred aspect, both the first contact surface and the second contact surface can be inclined by no more than 10°, preferably no more than 5°, particularly preferably no more than 2° relative to the radial direction. This avoids the occurrence of excessive radial forces during clamping of the rotor segments, which could contribute to bending of the rotor drum during operation.

[0014] In general, it should be noted that the use of the terms "first" and "second" rotor segments does not describe the formation of pairs within the rotor arrangement. In particular, for example, a second rotor segment can also function as the first rotor segment if another (total third) rotor segment is axially connected.

[0015] A gas turbine, in particular an aircraft gas turbine, can have at least one rotor arrangement as described above. In the gas turbine, the rotor arrangement can be part of a low-pressure turbine, a medium-pressure turbine, or a high-pressure turbine.

[0016] The invention is described below by way of example and not by way of limitation with reference to the attached figures. Fig. 1 shows a simplified schematic diagram of an aircraft gas turbine. Fig. 2shows a simplified and schematic representation of a sectional view of a rotor arrangement with several rotor segments. Fig. 3 shows an enlargement of a Fig. 2 area marked III.

[0017] Fig. 1shows a schematic and simplified illustration of an aircraft gas turbine 10, which is illustrated purely by way of example as a bypass engine. The gas turbine 10 comprises a fan 12, which is surrounded by an indicated casing 14. In the axial direction AR of the gas turbine 10, the fan 12 is followed by a compressor 16, which is accommodated in an indicated inner casing 18 and can be of single-stage or multi-stage design. The combustion chamber 20 is connected to the compressor 16. Hot exhaust gas flowing out of the combustion chamber then flows through the adjoining turbine 22, which can be of single-stage or multi-stage design. In the present example, the turbine 22 comprises a high-pressure turbine 24 and a low-pressure turbine 26. A hollow shaft 28 connects the high-pressure turbine 24 to the compressor 16, in particular a high-pressure compressor 29, so that they are driven or rotated together.A further internal shaft 30 in the radial direction RR of the turbine connects the low-pressure turbine 26 to the fan 12 and to a low-pressure compressor 32, so that they are jointly driven and rotated. A thrust nozzle 33, only indicated here, is connected to the turbine 22.

[0018] In the illustrated example of an aircraft gas turbine 10, a turbine intermediate casing 34 is arranged between the high-pressure turbine 24 and the low-pressure turbine 26, said intermediate casing being arranged around the shafts 28, 30. Hot exhaust gases from the high-pressure turbine 24 flow through the turbine intermediate casing 34 in its radially outer region 36. The hot exhaust gases then enter an annular space 38 of the low-pressure turbine 26. Rotor blade rings 27 of the compressors 28, 32 and the turbines 24, 26 are shown as examples. For reasons of clarity, conventionally present guide vane rings 31 are shown as examples only for the compressor 32.

[0019] The following description of an embodiment of the invention relates in particular to parts of the turbine 22 arranged axially next to or one after the other.

[0020] Fig. 2 shows a simplified and schematic sectional view of a front rotor segment 40 and a rear rotor segment 42 of a rotor assembly 100. In this example, the front rotor segment 40 is a rotor blade ring. The rear rotor segment 42 is, in this example, a seal carrier element with a radially outwardly projecting seal section 44 of a labyrinth seal. However, the first rotor segment 40 and the second rotor segment 42 can also be other rotating components of the turbine 22 of the gas turbine 10.

[0021] The first rotor segment 40 has a first contact surface 40k. In this example, the first contact surface 40k is an axially rear surface section, in particular in the form of an annular surface of the front rotor segment 40. The second rotor segment 42 has a second contact surface 42k. In this example, the second contact surface 42k is an axially front surface section, in particular in the form of an annular surface of the rear rotor segment 42.

[0022] The first contact surface 40k and the second contact surface 42k are arranged opposite one another in the axial direction AR. The front rotor segment 40 and the rear rotor segment 42 are connected to one another or clamped against one another in the axial direction by means of a tie rod device (not shown here). As a result, the first contact surface 40k and the second contact surface 42k come into contact or are in contact with one another.

[0023] By means of the contact surfaces 40k, 42k, forces acting in particular in the axial direction AR are transmitted or supported within the assembly of rotor segments 40, 42.

[0024] Fig. 3 shows an enlargement of the Fig. 2 with the dash-dotted rectangle III of the area of ​​the two contact surfaces 40k, 42k as well as a further enlargement only for the area of ​​the contact surfaces 40k, 42k.

[0025] From these enlarged views, it can be seen that a gap 46 is formed at least partially or in sections between the two contact surfaces 40k, 42k. This gap has a small size of a few millimeters or fractions of millimeters.

[0026] In the example shown here, the second contact surface 42k of the rear rotor segment 42 is slightly inclined relative to the radial direction RR. A small or very acute angle α is thus formed between the first contact surface 40k and the second contact surface 42k. The inclination of the second contact surface 42k is selected such that the angle α is approximately 0.5° to 3°, in particular approximately 1°.

[0027] Due to the inclined arrangement of the two contact surfaces 40k, 42k relative to one another, axial forces can be better distributed and balanced in this area during operation of the gas turbine. This avoids undesirably high stresses compared to contact surfaces that are aligned parallel to one another. The gap 46 formed between the two contact surfaces 40k, 42k is closed due to the thermal and mechanical effects during operation of the gas turbine, so that the contact surfaces 40k, 42k bear against one another during operation. However, this does not result in the formation of a ring-shaped force transmission area on which such high axial forces act that material fretting or the like could occur. Due to the inclined arrangement and design of the contact surface 42k orof the contact surfaces 40k, 42k to each other, an improved stress distribution is created in which the material stress of the two rotor segments 40, 42 is more uniform. List of reference symbols

[0028] 10 Aircraft gas turbine 12 Fan 14 Shroud 16 Compressor 18 Inner casing 20 Combustion chamber 22 Turbine 24 High-pressure turbine 26 Low-pressure turbine 28 Hollow shaft 29 High-pressure compressor 30 Shaft 31 Guide vane ring 32 Low-pressure compressor 33 Exhaust nozzle 34 Turbine center casing 36 Radial outer area 38 Annular space 40 Front rotor segment 40 First contact surface 42 Rear rotor segment 42 Second contact surface 44 Sealing section 46 Intermediate space 100 Rotor arrangement α Angle

Claims

1. Rotor arrangement (100) for a gas turbine (10), in particular an aircraft gas turbine, comprising a plurality of rotor segments (40, 42) arranged one after the other in the axial direction (AR), which are connected to one another by at least one tie rod device in the axial direction (AR); a rotor segment (40) at the front in the axial direction (AR) having a first contact surface (40k) and a rotor segment (42) at the rear in the axial direction (AR) having a second contact surface (42k), the first contact surface (40k) and the second contact surface (42k) being at least partly in contact with each other, the first contact surface (40k) and the second contact surface (42k) being substantially annular and extending in the radial direction (RR) and circumferential direction, characterized in that the first contact surface (40k) and / or the second contact surface (42k) extends at least partly inclined with respect to the radial direction (RR), an angle (α) being formed between the first contact surface (40k) and the second contact surface (42k) with respect to a sectional plane which is spanned by the axial direction (AR) and the radial direction (RR), the front rotor segment and the rear rotor segment being clamped to one another only via a single contact surface pairing consisting of the first annular contact surface and the second annular contact surface.

2. Rotor arrangement (100) according to claim 1, characterized in that the first contact surface (40k) is substantially parallel to the radial direction (RR) and in that the second contact surface (42k) is inclined to the radial direction (RR).

3. Rotor arrangement (100) according to either claim 1 or claim 2, characterized in that the front rotor segment (40) is a rotor blade ring and in that the rear rotor segment (42) is a seal carrier.

4. Rotor arrangement (100) according to any of the preceding claims, characterized in that the angle (α) between the first contact surface (40k) and the second contact surface (42k) is 0.5° to 3°, in particular 0.8° to 1.2°.

5. Rotor arrangement (100) according to any of the preceding claims, characterized in that both the first contact surface (40k) and the second contact surface (42k) are inclined by no more than 10°, in particular no more than 5°, relative to the radial direction.

6. Gas turbine (10), in particular an aircraft gas turbine, comprising at least one rotor arrangement (100) according to any of the preceding claims.

7. Gas turbine (10) according to claim 6, wherein the rotor arrangement (100) is part of a low-pressure turbine (26) or of a medium-pressure turbine or of a highpressure turbine (24).