EP3109407A1 - Stator device for a turbo engine with a housing device and multiple guide vanes - Google Patents

Abstract

The invention relates to a stator device (5) for a turbomachine (1) with a housing device (8) and a plurality of guide vanes (12) which are arranged distributed on the housing device (8) on the circumference. The guide vanes (12) are each designed with an airfoil (13) and in each case at least one platform (14). The platforms (14) at least partially form a surface (27) of an annular channel (3) through which working fluid flows during operation of the stator device (5) and are adjustably mounted relative to the housing device (8). In this case, a gap region (31) is provided, which is at least in regions by a radial gap (28) between the platform (14, 19) and the housing device (8) in the region of the surface relative to a longitudinal axis (18) of the platform (14, 19) (27) of the annular channel (3) is formed. In the region of the gap (28), a sealing device (40) is provided.

Description

The invention relates to a stator device for a turbomachine, in particular an aircraft engine, with a housing device and a plurality of stator blades according to the type defined in more detail in patent claim 1.

Stator devices of compressors for aircraft engines, which are designed with adjustable about a central axis trained vanes are well known in the art. The circumferentially distributed arranged in a housing means vanes each have an airfoil and a subsequent radially outward direction of the stator device, also referred to as penny platform, the platforms together with the housing means defining a core flow channel of the aircraft engine in the radial direction of the stator. In turn, in the radial direction of the aircraft engine on a side facing away from the blades of the platforms is followed in each case by a spindle-shaped region over which the guide vanes are rotatably mounted about the central axis of the spindle-shaped region relative to the housing means. The platform, which has a circular cross-section with respect to the central axis of the spindle-shaped area, has a larger cross section than the spindle-shaped area with respect to the central axis of the spindle-shaped area. The platforms are each mounted in a recess of the housing device which is concentric with the central axis of the spindle-shaped area, the housing device and the platform being spaced apart from one another in the radial direction of the central axis of the spindle-shaped area, so that there is a circumferential gap between the housing device and the platforms of the guide vanes , In addition, a surface facing away from the core flow channel of the platforms with respect to the housing device in the radial direction is spaced.

A turbomachine designed with such a stator device disadvantageously has an unsatisfactory efficiency.

It is an object of the present invention to provide a stator device in which an efficiency of a turbomachine provided with such a stator device is improved.

According to the invention, this object is achieved with a stator device having the features of patent claim 1.

The invention relates to a stator device of a compressor or a turbine for a turbomachine, in particular an aircraft engine or a stationary gas turbine, with a housing device and a plurality of guide vanes, which are arranged circumferentially distributed on the housing device, the guide vanes each having an airfoil and in each case at least one platform (Penny) are executed. The platforms form, at least in regions, a surface of an annular channel through which working fluid flows during operation of the stator device and are adjustably mounted relative to the housing device, a gap region being provided, at least in regions, by a radial gap between the platform and the housing device in relation to a longitudinal axis of the platform Area of the surface of the annular channel is formed. According to the invention, a sealing device is provided in the region of the gap.

The solution according to the invention is based on the recognition that in operation of a turbomachine in conventionally designed stator devices through the gap region, which in addition to the radial gap by an axial spacing - with respect to the longitudinal axis of the platform - between a surface facing away from the annular channel of the platform and the Housing device may be formed, a part of the guided through the annular channel working fluid is guided as a leakage flow. This leakage flow is due to a pressure difference between the pressure side and the suction side of the airfoil or an increasing pressure gradient in the flow direction of the working fluid in the annular channel through the gap region, wherein the leakage flow in particular via the gap in the region of the downstream pressure side of the blade and the side facing away from the annular channel of the platform to an upstream suction side of the blade and there is guided over the gap in the annular channel. When the leakage flow in the region of the suction side of the blade leaves the gap region, the leakage flow from the gap region interacts with the main flow of the working fluid in the annular channel, wherein a so-called blocking region with a flow velocity reduced relative to surrounding regions of the main flow occurs in the main flow. This effect causes the leakage flow has a significant negative impact on the efficiency of the turbomachine.

The provision of the sealing device in the solution according to the invention has the advantage that the gap region during operation of the stator at least partially in the radial direction of the stator or in the axial direction of the longitudinal axis of the platform is sealable, so that a mass flow of the leakage flow, in the region of the suction side of the airfoil enters the main flow of the annular channel from the gap, reduced or flow of leakage flow into the annular channel in the region of the suction side of the airfoil is completely prevented.

A lossy interaction of the leakage flow with the main flow is hereby reduced or completely eliminated, so that an efficiency of a turbomachine designed with the stator device according to the invention is increased over known embodiments without such a sealing device.

This also results in a reduced specific fuel consumption of a turbomachine designed with the stator device according to the invention, this being a significant advantage, in particular in the case of an aircraft engine.

The leakage flow through the gap region is particularly greatly reduced if the sealing device extends in the radial direction-with respect to the longitudinal axis of the platform-from the platform to the housing device and thus radially overlaps the entire gap.

In an advantageous embodiment of the stator device according to the invention, provision may be made for the sealing device to be designed to revolve at least approximately the platform with respect to the longitudinal axis of the platform. The leakage flow in the region of the gap can be completely eliminated here.

The sealing in the region of the gap between the platform and the housing device is particularly effective if the sealing device is arranged in an area of the gap adjacent to the annular channel. In such an embodiment of the invention, a leakage flow can be prevented in an annular channel near the area around the platform.

In a marked by a long life embodiment of the invention, the sealing device with a particular high temperature resistant material, such as polytetrafluoroethylene or the like, executed.

The sealing device can be arranged in a structurally particularly simple manner in the region of the gap, if the sealing device is arranged at least partially in a substantially radial direction with respect to the central axis facing groove of the platform and / or a groove of the housing device.

A simple and cost-effective designed stator device is when the sealing device is designed as an O-ring, as a piston ring with in particular circumferentially spaced ends or as a shaft seal.

The platform of the guide vane may be arranged in an inner and / or outer edge region of the vane with respect to the radial direction of the stator device, wherein a sealing device is preferably arranged in a gap between the respective platform and the housing device in the region of each platform.

Both the features specified in the claims and the features specified in the subsequent embodiments of the stator device according to the invention are each suitable for use alone or in any combination with each other to develop the subject invention.

Further advantages and advantageous embodiments of a stator according to the invention will become apparent from the claims and the following with reference to the embodiments described in principle in the drawing, wherein for the sake of clarity, the same reference numerals are used for construction and functionally identical components.

Fig. 1

eine stark schematisierte Längsschnittansicht eines Ausschnitts eines Strahltriebwerks, wobei ein Verdichter mit mehreren Rotorvorrichtungen und Statorvorrichtungen gezeigt ist, die jeweils in einen Kernstromkanal ragende Schaufeln aufweisen;

Fig. 2

eine vereinfachte Längsschnittdarstellung durch einen Teil einer Statorvorrichtung der Fig. 1, wobei eine im Bereich eines Spalts zwischen der Plattform und einer Gehäuseeinrichtung angeordnete Abdichteinrichtung in einer ersten Ausführungsform gezeigt ist,

Fig. 3

eine stark vereinfachte Darstellung der Abdichteinrichtung in Alleinstellung;

Fig. 4

eine der Fig. 2 entsprechende Ansicht der Statorvorrichtung gemäß Fig. 1, wobei eine zweite Ausführungsform der Abdichteinrichtung dargestellt ist;

Fig. 5

eine der Fig. 2 und Fig. 4 entsprechende Ansicht der Statorvorrichtung gemäß Fig. 1, wobei eine dritte Ausführungsform der Abdichteinrichtung gezeigt ist; und

Fig. 6

eine der Fig. 2, Fig. 4 und Fig. 5 entsprechende Ansicht der Statorvorrichtung gemäß Fig. 1, mit einer Abdichteinrichtung in einer vierten Ausführungsform.

It shows:

Fig. 1

a highly schematic longitudinal sectional view of a section of a jet engine, wherein a compressor having a plurality of rotor devices and stator devices is shown, each having projecting into a core flow channel blades;

Fig. 2

a simplified longitudinal section through a part of a stator of the Fig. 1 in which a sealing device arranged in the region of a gap between the platform and a housing device is shown in a first embodiment,

Fig. 3

a greatly simplified representation of the sealing device in isolation;

Fig. 4

one of the Fig. 2 corresponding view of the stator according to Fig. 1 showing a second embodiment of the sealing device;

Fig. 5

one of the Fig. 2 and Fig. 4 corresponding view of the stator according to Fig. 1 showing a third embodiment of the sealing device; and

Fig. 6

one of the Fig. 2 . 4 and FIG. 5 corresponding view of the stator according to Fig. 1 , with a sealing device in a fourth embodiment.

Fig. 1 shows a section of a turbomachine, which in the present case is designed as a jet engine 1 of an aircraft, but in an alternative embodiment may also be a stationary gas turbine. In the section, an annular channel or core flow channel 3 of the jet engine 1 is shown in the region of a high-pressure compressor 2 Schaufelradvorrichtung, wherein various stages 6A, 6B, 6C, 6D of the high-pressure compressor 2 can be seen, each consisting of a rotor device 4 and one in the axial direction A of the jet engine 1 downstream of the rotor device 4 arranged stator 5 exist.

In the following, the rotor device 4 and the stator device 5 of the third stage 6C of the high-pressure compressor 2 will be described in more detail, the rotor devices 4 and the stator devices 5 of the other stages 6A, 6B, 6D being made comparable.

The rotor device 4 has a multiplicity of rotor blades 9, which are designed with blades 10 and are circumferentially distributed with a disk wheel 11 are operatively connected and rotate during operation of the jet engine 1 about a central axis of the jet propulsion system 1. On the other hand, the stator device 5 is designed with a large number of guide vanes 12, each of which has an airfoil 13, wherein the guide vanes 12, which are constructed identically, are arranged on the outside of a housing device 8 distributed in the radial direction R of the jet engine 1.

The blades 13 of the guide vanes 12 in the radial direction R of the jet engine 1 to the outside respectively to a platform 14 and a so-called penny. The platforms or pennies 14 delimit the core flow channel 3 in the radial direction R of the jet engine 1, at least in regions, and are viewed radially outwardly, in each case connected to a spindle-shaped region 15 and in the present case designed integrally therewith. In this case, the platforms 14 have a larger cross-section than the spindle-shaped area 15 with respect to a central axis 18 of the spindle-shaped area 15. The guide vanes 12 are arranged with the platforms 14 and the spindle-shaped regions 15 in recesses 16 of the housing device 8, wherein the spindle-shaped regions 15 are mounted in the recesses 16 via bushes 17.

The guide vanes 12 are rotatably arranged in the recesses 16 of the housing device 8 in a known manner about the central axis 18 of the spindle-shaped region 15, which is congruent to the longitudinal axis of the platform 14, wherein the guide vanes 12, for example via the spindle-shaped regions 15 by 5 ° to 60 ° relative to the housing device 8 are rotatable.

On a relative to the radial direction R of the jet engine 1 and the stator 5 inner side of the blade 13 is also a platform 19 is provided, which is executed in a comparable manner to the platform 14 with a spindle-shaped portion 20 and the core flow channel 3 at least partially in the radial Limited R direction of the jet engine 1. About the spindle-shaped portion 20, the guide vane 12 in turn via a socket 21 in one Housing part 22 of the housing device 8, a so-called Shroud, stored, wherein the guide vane 12 is rotatably mounted about the central axis 18 relative to the housing part 22. The housing part 22 is arranged overall in a recess 24 which is formed by two rotor devices 4 which are adjacent to one another in the axial direction A of the jet engine 1 or the stator device 5. During operation of the jet engine 1, the area of the rotor device 4 facing the housing part 22 rotates about the engine axis, whereas the housing part 22 is stationary with respect to the engine axis.

In Fig. 2 a detail of the stator device 5 with the spindle-shaped portion 15 and the platform 14 of the guide vane 12 is shown in more detail. It can be seen here that the platform 14, which has a circular cross-section, and the spindle-shaped region 15, which is likewise designed with a circular cross section, are mounted in the recess 16 of the housing device 8 which is concentric with the central axis 18. Between the platform 14 and the housing device 8, in the region of a surface 27 of the core flow channel 3, there is a gap 28 which circulates in the radial direction r, starting from the surface 27 of the core flow channel 3 substantially in the axial direction a of the central axis 18 extends to the outside.

Of the Fig. 2 It can also be seen that a surface 30 of the platform 14 facing away from the core flow channel 3 is spaced apart from the housing device 8 in the radial direction R of the jet engine 1. By this with respect to the central axis 18 of the spindle-shaped region 15 axial distance and with respect to the central axis 18 radial gap 28, a gap region 31 is formed.

During operation of the jet engine 1, a pressure of a working fluid, here air, rises in the area of the high-pressure compressor 2 in the core flow channel 3 in the axial direction A of the jet engine 1 and thus in the flow direction, so that a pressure of a main flow flowing through the core flow channel 3 on a pressure side 33 of the airfoil 13 of the vane 12 is greater than on a As a result of these pressure ratios, part of the main flow flows as leakage flow from the pressure side 33 of the airfoil 13 through the gap region 31 to the suction side 34 of the airfoil 13 due to these pressure conditions. The leakage flow is determined by the pressure-side region of the airfoil Slit 28 is guided over the core flow channel 3 facing away from the surface 30 to the suction-side region of the gap 28.

The inflow of the leakage flow in the region of the suction side 34 of the airfoil 10 into the main flow leads to considerable losses in the known jet engines since a velocity of the main flow in this region is undesirably reduced by the leakage flow and a so-called blockage or loss region arises.

In order to reduce or completely prevent a mass flow of the leakage flow, which is introduced into the main flow during operation of the jet engine 1 on the suction side 34 of the blade 13, is in Fig. 2 a designed as a piston ring 40 sealing provided, which is arranged in the gap 28 and in Fig. 3 in isolation can be seen.

The present case with resistant polytetrafluoroethylene executed piston ring 40 is arranged both in a groove 41 of the platform 14 and in a groove 42 of the housing device 8, so that a width of the gap 28 in the radial direction r with respect to the central axis 18 of the piston ring 40 completely covers becomes. In order to mount the piston ring 40 in a simple manner, this is designed in the manner of an annular disc with a recess 44. Thus, the piston ring 40 rotates in the assembled state, the central axis 18 in the circumferential direction u almost completely.

The piston ring 40 is preferably arranged in a gap directly adjacent to the core flow channel 3 or a surface 27 of the core flow channel 3 in the gap 28, so that in the radial direction R of the jet engine 1 within the flow area 43 present in the piston ring 40 is minimized or completely eliminated. The closer the piston ring 40 is arranged in the region of the gap 28 on the surface 27 of the core flow channel 3, the smaller the flow region 43 and thus also the leakage flow during operation of the jet engine 1.

About the piston ring 40 can be achieved in a simple manner that during operation of the jet engine 1 on a side facing away from the core flow channel 3 of the piston ring 40 no or only one compared to conventional designs without a piston ring 40 greatly reduced leakage flow flows.

In Fig. 4 to Fig. 6 are shown to the piston ring alternative embodiments of a sealing device 46, 47, 48, wherein in the following only the differences from the embodiment described in more detail above are shown.

The sealing device 46 according to Fig. 4 is designed as an O-ring, wherein the O-ring 46 is held in its position by means of a groove 50 provided in the housing device 8. The O-ring 46 bears against a side surface 51 of the platform 14 that extends essentially in the radial direction R of the jet engine 1. Characterized in that the O-ring 46 in the circumferential direction u of the central axis 18 is performed completely circumferential and the gap 28 in the radial direction r of the central axis 18 completely seals, is achieved with this embodiment in a particularly secure manner that on a side facing away from the core flow channel 3 of the O-ring 46 working gas can flow as a leakage flow.

According to Fig. 5 is also shown as an O-ring sealing device 47 is shown, which is arranged in contrast to the sealing device 46 in a provided in the platform 14 groove 52. In this case, the O-ring 47 bears against a side surface 58 of the housing device 8 which extends essentially in the radial direction R of the jet engine 1. The O-ring 47 has the same effect as the O-ring 46 and is also completely circumferential in the circumferential direction u of the central axis 18 executed so that the gap 28 is completely sealed in this embodiment in the radial direction r of the central axis 18.

In Fig. 6 the sealing device is designed as a shaft sealing ring 48, which rests in the region of a shoulder 53 of the housing device 8 at this. The shaft sealing ring 48 is again made with polytetrafluoroethylene, but has an integrated reinforcement 54. The reinforcement 54 is embedded in a radial direction R of the jet engine 1 extending leg 55, which cooperates in the assembled state with a substantially in the axial direction a with respect to the central axis 18 extending side surface 58 of the housing means 8. Furthermore, the reinforcement 54 has a substantially in the radial direction r with respect to the central axis 18 extending portion 56, which is designed as a circular ring. In the assembled state, the shaft sealing ring 48 cooperates with a surface 59 of the housing device 8 via the region 56, which likewise runs essentially in the radial direction r with respect to the central axis 18.

The shaft seal 48 further has a sealing lip 61, which is designed to cooperate with the side surface 51 of the platform 14. In order to press the sealing lip 61 in operation of the jet engine 1 with a desired contact pressure to the platform 14, the shaft seal 48 has a traction spring 62 designed as traction means. The tension spring 62 is arranged on one of the platform 14 in the radial direction r of the central axis 18 side facing away from the sealing lip 61 and running circumferentially.

In all embodiments of the sealing device 40, 46, 47, 48, the sealing device 40, 46, 47, 48 interacts with the platform 14 and / or the housing device 8 in such a way that the guide blade 12 can be adjusted in a simple manner around the central axis 18. The pressing forces of the sealing device 40, 46, 47, 48 on the platform 14 and / or the housing device 8 are adjusted to a predetermined value accordingly.

In the area of the platform 19, similar to the arrangement of the sealing devices 40, 46, 47, 48 in the region of the platform 14 also a sealing device can be arranged in a comparable manner, wherein the sealing means between the platform 19 and the housing part 22 in the of these components in radial direction r with respect to the central axis 18 formed gap 28 can be arranged.

LIST OF REFERENCE NUMBERS

1

Flow machine; Jet engine

2

Schaufelradvorrichtung; High-pressure compressors

3

Core flow channel, ring channel

4

rotor device

5

stator

6A to 6D

Steps of the high pressure compressor

8th

housing means

9

blade

10

Blade of the blade

11

Scheibenrad

12

vane

13

Airfoil of the vane

14

Platform, penny

15

spindle-shaped area

16

Recess of the housing device

17

Rifle

18

central axis

19

platform

20

spindle-shaped area

21

Rifle

22

housing part

24

recess

27

Surface of the core flow channel

28

gap

30

Surface of the platform

31

gap region

33

Pressure side of the airfoil

34

Suction side of the airfoil

40

Sealing device, piston ring

41

Groove of the platform

42

Groove of the housing device

43

flow region

44

Recess of the piston ring

46

Sealing device, O-ring

47

Sealing device, O-ring

48

Sealing device, shaft seal

50

Groove of the housing device

51

Side surface of the platform

52

Groove of the platform

53

Paragraph of the housing device

54

Reinforcement of the shaft seal

55

Leg of the shaft seal

56

Area of the shaft seal

58

Side surface of the housing device

59

Surface of the housing device

61

Sealing lip of the shaft seal

62

traction means; mainspring

a

axial direction of the vane

A

axial direction of the jet engine

r

radial direction vane

R

radial direction of the jet engine

u

Circumferential direction to the central axis of the vane

U

Circumferential direction of the jet engine

Claims (11)

Stator device (5) for a turbomachine (1) with a housing device (8) and a plurality of guide vanes (12) distributed circumferentially on the housing means (8) are arranged, wherein the guide vanes (12) each with an airfoil (13) and in each case at least one platform (14, 19) are executed, wherein the platforms (14, 19) at least partially form a surface (27) of an operating during operation of the stator (5) with working fluid annular channel (3) and relative to the housing means (8) adjustable are provided, and wherein a gap region (31) is provided, at least partially by a relative to a longitudinal axis (18) of the platform (14, 19) radial gap (28) between the platform (14, 19) and the housing device (8). is formed in the region of the surface (27) of the annular channel (3), characterized in that a sealing device (40, 46, 47, 48) is provided in the region of the gap (28). Stator device according to claim 1, characterized in that the sealing device (40, 46, 47, 48) in the radial direction (r) with respect to the longitudinal axis (18) of the platform (14, 19) from the platform (14, 19) up to the housing device (8) extends. Stator assembly according to any one of claims 1 or 2, characterized in that the sealing means (40, 46, 47, 48) is executed with respect to the longitudinal axis (18) of the platform (14, 19) at least approximately the platform (14, 19) circumferentially. Stator device according to one of Claims 1 to 3, characterized in that the sealing device (40, 46, 47, 48) is arranged in a region of the gap (28) adjoining the annular channel (3). Stator device according to one of claims 1 to 4, characterized in that the sealing device (40, 46, 47, 48) with a temperature-resistant material, in particular polytetrafluoroethylene, is executed. Stator device according to one of claims 1 to 5, characterized in that the sealing device (40) at least partially in a substantially in the radial direction (r) with respect to the central axis (18) facing groove (41, 52) of the platform (14, 19) is arranged. Stator device according to one of claims 1 to 6, characterized in that the sealing device (40, 46) at least partially in a substantially in the radial direction (r) with respect to the central axis (18) facing groove (42, 50) of the housing device (8). is arranged Stator device according to one of claims 1 to 7, characterized in that the sealing device (46, 47) is designed as an O-ring. Stator device according to one of claims 1 to 7, characterized in that the sealing device (40) is designed as a piston ring. Stator device according to one of claims 1 to 7, characterized in that the sealing device (48) is designed as a shaft seal. Stator device according to one of claims 1 to 10, characterized in that the platform (14, 19) of the vane (12) in a relative to the radial direction (R) of the stator device (5) inner and / or outer edge region of the airfoil (13) is arranged, wherein preferably in the region of each platform (14, 19) sealing means (40, 46, 47, 48) in the gap (28) between the respective platform (14, 19) and the housing means (8) is arranged.

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