RETAINING DEVICE FOR AXIALLY RETAINING A BLADE AND ROTOR DEVICE WITH SUCH A RETAINING DEVICE

Abstract

A securing device with multiple securing segments for the axial retaining of at least one rotor blade at a disc wheel a rotor device of a continuous-flow machine. The securing device has at least one effective area that is arranged in a radially inner area and that in the mounted state is embodied for acting together with the disc wheel in the axial direction of the rotor device, and a further effective area that is arranged in a radially outer area at a securing segment and that in the mounted state is embodied for acting together with at least one rotor blade in the axial direction of the rotor device. At least one securing segment has an additional effective area, that in the mounted state is embodied for acting together with the disc wheel in the radial direction of the rotor device. What is further described is a rotor device with such a securing device.

Claims

1. A securing device for the axial retaining of at least one rotor blade at a disc wheel of a rotor device of a continuous-flow machine with multiple securing segments, wherein the securing device has at least one effective area -(2 that is arranged in a radially inner area and that in the mounted state is embodied for acting together with the disc wheel in the axial direction of the rotor device, and a further effective area that is arranged in a radially outer area at a securing segment and that in the mounted state is embodied for acting together with at least one rotor blade in the axial direction of the rotor device, wherein at least one securing segment has an additional effective area that in the mounted state is embodied for acting together with the disc wheel in the radial direction of the rotor device.

2. The securing device according to claim 1, wherein the additional effective area is arranged at the at least one securing segment in the mounted state in a manner substantially concentric with respect to a central axis of the rotor device.

3. The securing device according to claim 1, wherein the effective that are oriented in the axial direction in the mounted state of the securing device are configured so as to be substantially parallel to a plane that extends perpendicularly to the central axis of the rotor device.

4. The securing device according to claim 1, wherein the at least one securing segment has a support area that in the mounted state is embodied for acting together with a rotor blade of the rotor device, wherein the support area in the mounted state is preferably arranged in an area of the securing segment that is central with respect to the radial direction of the rotor device.

5. The securing device according to claim 1, wherein it comprises a securing element that comprises the effective area, which in the mounted state acts together with the disc wheel in the axial direction, and which acts together in the mounted state with at least one associated securing segment in the radial direction and/or the axial direction of the rotor device.

6. The securing device according to claim 1, wherein, in a radially inner area, the at least one securing segment has a hook-shaped area that extends in the axial direction, wherein the effective area that in the mounted state acts together with the disc wheel in the axial direction is configured at an inner wall of the hook-shaped area.

7. A rotor device for a continuous-flow machine with a disc wheel and multiple rotor blades that are arranged at the disc wheel in a circumferentially distributed manner, wherein the rotor blades are respectively arranged via a blade root inside recesses of the disc wheel that substantially extend in the axial direction of the rotor device, and wherein a securing device according to claim 1 multiple securing segments arranged in a circumferentially distributed manner is provided for the axial retaining of the rotor blades at the disc wheel.

8. The rotor device according to claim 7, wherein the disc wheel has a first support surface and a second support surface, and the rotor blades have a further support surface, wherein the first support surface of the disc wheel acts together with the at least one effective area of the securing device that is oriented in the axial direction, the second support surface acts together with the additional effective area of the securing segments that is oriented in the radial direction, and the further support surface acts together with the further effective area of the securing segments ;that is oriented in the axial direction.

9. The rotor device according to claim 8, wherein the disc wheel has a recess, in the area of which the first support surface is arranged.

10. The rotor device according to claim 8, wherein the disc wheel has a groove that is formed by a projection and that is open inwards in the radial direction of the rotor device, wherein the first support surface of the disc wheel is a part of the groove, and wherein the projection in particular also comprises the second support surface.

11. The rotor device according to claim 10, wherein the securing segments surround the projection of the disc wheel.

12. The rotor device according to claim 7, wherein the further support surface is arranged at the rotor blades in the area of a cooling air outlet that forms a microturbine.

13. The rotor device according to claim 7, wherein a securing segment has lateral surfaces that are embodied so as to be parallel to each other or so as to substantially extend in the radial direction of the rotor device as viewed in the circumferential direction of the rotor device.

14. The rotor device according to claim 7, wherein at least one retaining appliance is provided for retaining one or multiple securing segments in its or their position.

15. The rotor device according to claim 7, wherein the lateral surfaces of at least two adjacent securing segments are embodied in a design in which they axially overlap each other in the gap area.

Description

[0042] Herein:

[0043] FIG. 1 shows a strongly schematized longitudinal section view of a jet engine that has a turbine with multiple rotor devices;

[0044] FIG. 2 shows a schematized section of the jet engine of FIG. 1 with a rotor device comprising a disc wheel and rotor blades that are circumferentially arranged thereat, wherein the rotor blades are respectively secured at the disc wheel in the axial direction by means of a securing device;

[0045] FIG. 3 shows a simplified rendering of an enlarged section of FIG. 2, wherein the securing device can be seen in more detail;

[0046] FIG. 3a shows a rendering of a security device at rotor blades that is in principle embodied according to the embodiment in FIG. 3 that corresponds to FIG. 3, with the rotor blades being configured with an axial cooling air outlet that forms a microturbine;

[0047] FIG. 4 shows a view of the rotor device according to FIG. 2 that corresponds to FIG. 3, wherein a second embodiment of a securing device can be seen;

[0048] FIG. 4a shows a view of a security device at rotor blades corresponding to

[0049] FIG. 4 that is in principle configured according to the embodiment in FIG. 4, with the rotor blades being configured with an axial cooling air outlet that forms a microturbine;

[0050] FIG. 5 shows a view of a section of the securing device according to FIG. 4 in a strongly simplified manner, wherein a retaining appliance can be seen in more detail;

[0051] FIG. 6 shows a strongly simplified view of the securing device according to

[0052] FIG. 4 from the rear side in isolation with numerous securing segments;

[0053] FIG. 7 shows a view of a further embodiment of the securing device corresponding to the rendering of FIG. 6 with a symbolically indicated rotor blade, wherein the securing device is embodied in the kind of a snap ring with an end segment; and

[0054] FIG. 8 shows the lateral surfaces of two adjoining securing segments in isolation, wherein the latter are embodied so as to axially overlap each other.

[0055] FIG. 1 shows a continuous-flow machine that is embodied as a jet engine 1 in a longitudinal section view, wherein the jet engine 1 is configured with a bypass channel 2 and an inflow area 3. A fan 4 connects downstream to the inflow area 3 in a per se known manner. In turn, downstream of the fan 4 the fluid flow in the jet engine 1 is divided into a bypass flow and a core flow, wherein the bypass flow flows through the bypass channel 2 and the core flow flows into an engine core or core flow channel 5, which is again embodied in a per se known manner with a compressor appliance 6, a burner 7, and a turbine appliance 8.

[0056] In the present case, the turbine appliance 8 is embodied in multiple-stage design with two high-pressure rotor devices 9A, 9B of which the rotor device 9A can be seen in more detail in FIG. 2, and three substantially comparatively designed low-pressure rotor devices 10A, 10B, 10C.

[0057] Here, the rotor device 9A and a stator device 13 that is arranged downstream of the rotor device 9A in the axial direction A of the jet engine 1 form a first stage 14 of the turbine appliance 8. The rotor device 9A is embodied with a centrally arranged disc wheel 17, which is connected to an engine shaft 11 and is mounted so as to be rotatable around a central axis 16. A plurality of rotor blades 18 is circumferentially arranged at the disc wheel 17 in the radially outer areas, wherein for this purpose the rotor blades 18 respectively have a blade root 19 that is shown here only schematically and that is configured with a so-called fir-tree profile, and via which the rotor blades 18 are respectively arranged in a known manner inside recesses 20 of the disc wheel 17 which substantially extend in the axial direction inside the disc wheel 17 and correlate with the profiled blade roots 19.

[0058] In the present case, for the purpose of axially retaining the rotor blades 18 with respect to the disc wheel 17, a securing device 22 is provided on a side of the rotor device 9A that is facing away from the flow with respect to a flow direction of a working gas inside the core flow channel 5, which comprises multiple, preferably approximately four or five, securing segments 23 that are substantially embodied so as to be structurally identical. Here, the flow direction of the working gas inside the core flow channel substantially corresponds to the axial direction A of the jet engine 1.

[0059] In an inner area with respect to a radial direction R of the jet engine 1, the securing device 22 that can be seen in FIG. 3 in more detail is arranged inside a recess 24 of the disc wheel 17 that extends in the circumferential direction U of the jet engine 1, and in an outer area with respect to the radial direction R of the jet engine 1 inside a groove 25 of the rotor blades 18 that extends in the circumferential direction U of the jet engine 1.

[0060] In an area of the recess 24 of the disc wheel 17, the securing device 22 has a securing element that is embodied as a snap ring 26 here, and that is embodied with an effective area 27 that is arranged substantially perpendicular to the axial direction A of the jet engine 1, with its surface being oriented in the flow direction A.

[0061] Via the effective area 27, the snap ring 26 acts together with a first support surface 28 of the disc wheel 17 that is also located substantially in a plane perpendicular to the axial direction A of the jet engine 1, and that in the present case is a part of a projection 29 that delimits the recess 24 at least in certain areas in the axial direction A of the jet engine 1 and that extends substantially in the radial direction R of the jet engine 1. Here, a surface of the part of the projection 29 that comprises the support surface 28 is oriented counter to the flow direction A.

[0062] In the radially outer area, the securing segment 23 has a further effective area 31, which is again located substantially in a plane perpendicular to the axial direction A of the jet engine 1 and is oriented downstream. This further effective area 31 is provided for acting together with a further support surface 32 that is part of a projection 33 that delimits the groove 25 in the axial direction A of the jet engine 1 and that substantially extends in the radial direction R of the jet engine 1. Here, the further support surface 32 is also arranged in a plane substantially perpendicular to the axial direction A of the jet engine 1, wherein a surface of a part of the projection 33 that comprises the further support surface 32 is oriented counter to the flow direction A.

[0063] Further, the securing segment 23 is embodied in the radially inner area with an additional effective area 35 that is arranged in a substantially concentric manner with respect to the central axis 16 of the jet engine 1, wherein a surface of a part of the securing segment 23 that comprises the additional effective area 35 is oriented outward in the radial direction R of the jet engine 1. In the mounted state of the securing device 22, the securing segment 23 acts together via the additional effective area 35 with an additional support surface 38 of the disc wheel 17, which is also embodied in a substantially concentric manner with respect to the central axis 16 of the jet engine 1 and is formed by the disc wheel 17 in the area of the recess 24. Here, a surface of the part of the disc wheel 17 that comprises the additional support surface 38 is oriented substantially inward with respect to the radial direction R of the jet engine 1.

[0064] The snap ring 26 as well as the securing segment 23 respectively have two surfaces 40, 41 or 42, 43, via which the two elements act together. Here, the surfaces 40 and 41 are respectively located in a plane that extends in a substantially perpendicular manner with respect to the axial direction A of the jet engine 1, while the surfaces 42 and 43 are arranged in a substantially concentric manner with respect to the central axis 16 of the jet engine 1, so that the securing segment 23 is supported at the snap ring 26 via the surface 40 in the axial direction A of the jet engine 1, and is supported at the disc wheel 17 via its effective area 27.

[0065] Via the surface 43, the securing segment 23 is in turn retained by the snap ring 26 against a movement inward in the radial direction R of the jet engine 1, so that it is thus avoided that the securing segment 23 loses mesh with the groove 25 with its radial outer area when the rotor device 9A is not rotating, and is thus securely retained at the disc wheel 17 as well as at the rotor blades 18.

[0066] The securing segment 23 further has a support area 45 with a nose 46, via which the securing segment 23 acts together with the at least one rotor blade 18 in the axial direction A of the jet engine 1.

[0067] With the securing device 22, the rotor blades 18 are advantageously secured at the disc wheel 17 against a movement in the flow direction or the axial direction A as well as against a movement opposite to the flow direction. If an outer force effect is applied to the rotor blades 18 in the axial direction A with respect to the disc wheel 17, the securing segments 23 are supported at the disc wheel 17 through shearing by means of a lever that extends in the radial direction R of the jet engine 1 from the support area 45 to the inner area of the securing segments 23. However, if an outer force effect counter to the axial direction A with respect to the disc wheel 17 is applied to the rotor blades 18, the securing segments 23 are supported through shearing at the rotor blades 18 by means of a lever that extends in the radial direction R of the jet engine 1 from the support area 45 to the outer area of the securing segment 23.

[0068] If the support area 45 is arranged in a substantially central area with respect to the radial direction R of the jet engine 1 between the inner area and the outer area of the securing segment 23, both levers have approximately the same length, so that via the securing segments 23 a movement of the rotor blades 18 can be reliably retained in the as well as counter to the axial direction A.

[0069] For the purpose of mounting the securing device 22 at the disc wheel 17 and the rotor blades 18, first a diameter of the snap ring 26, which is embodied with an opening in the circumferential direction, is widened, so that the snap ring 26 can be inserted into the recess 24 at the disc wheel 17 via the projection 29, wherein the snap ring 26 is retained inside the recess 24 with a diameter that is reduced as compared to a diameter in the finished mounting state. Subsequently, the securing segments 23 are brought into mesh with the grooves 25 of the rotor blades 18, which are not yet in mesh with the recesses 20 of the disc wheel 17, with their radial outer areas.

[0070] If the rotor blades 18 are inserted into the recesses 20 of the disc wheel 17 substantially in the axial direction of the jet engine 1, the securing segments 23 are also inserted into the recess 24 of the disc wheel 17 and are guided in the radial direction R of the jet engine 1 via the snap ring 26. Subsequently, a diameter of the snap ring 26 is increased, so that the securing segments 23 act together via their surfaces 40, 42 with the surfaces 41, 43 of the snap ring 26, and with the additional effective area 35 act together with the additional, second support surface 38 of the disc wheel 17, and the spring ring acts together with its effective area 27 with the support surface 28 of the disc wheel 17.

[0071] In principle it is also conceivable that the securing segments 23 are inserted into the recess 24, into which the snap ring 26 is already inserted, when the rotor blades 17 have already been mounted in the recesses 20 of the disc wheel 17.

[0072] In the alternative embodiment shown in FIG. 3a, the securing device 22 has multiple, preferably approximately four or five, securing segments 23 that are embodied so as to be substantially structurally identical, and that are in principle embodied like the securing segments 23 shown in FIG. 3 with respect to their structure and their effective areas. In contrast to the embodiment according to FIG. 3, here the projection 33 of the rotor blade 18 with the groove 25 and the further support surface that is configured at the projection 33 for acting together with the further effective area 31 are part of a coating for a cooling air channel outlet 34 that is configured as a microturbine. In a manner corresponding to its radial arrangement in the radially inner area of the rotor blade 18, the respective securing segment 23 is configured so as to be radially shortened.

[0073] Such cooling air outlets 34 are configured for example with a nozzle-like extension in the flow direction A for the purpose of decreasing the flow-pressure during exit of the cooling air from an axial cooling air channel of the rotor blade 18, and can be configured with a flow deflection depending on the application case.

[0074] In further embodiments it is also conceivable that the projection 33 forming the microturbine is configured as a separate structural component with a suitable fixing at the rotor blade 18, wherein the mesh of the securing segments 23 is provided in an analogous manner.

[0075] FIG. 4 shows an alternatively embodied securing device 50 with securing segments 51, which acts together with the rotor blades 18 in the area of the groove 25 and via the support area 45 in a manner comparable to the securing segments 23. The securing segments 51 are thus embodied in a radially central and outer area in a manner comparable to the securing segments 23 of the securing device 22. In a radially inner area, the securing segments 51 have a hook-shaped area 53, which acts together with the disc wheel 55 that is embodied in the connection area in an alternative manner to the disc wheel 17 in the mounted state of the securing segments 51.

[0076] In contrast to the disc wheel 17, the disc wheel 55 does not have recess 24 for this purpose, but a projection 56 that runs all along the circumferential direction U of the jet engine 1 and is configured in a nose-shaped manner, forming a groove 57 that is substantially open inwards in the radial direction R of the jet engine 1.

[0077] In the mounted state of the securing segments 51, these surround the projection 56 with the hook-shaped area 53 and mesh with the groove 57 of the disc wheel 55. Thus, the securing segments 51 are arranged inside the projection 56 in the radial direction R of the jet engine 1, wherein, in the area that surrounds the projection 56, the hook-shaped area 53 comprises the additional effective area 35 that is arranged in a substantially concentric manner with respect to the central axis 16 and that is configured for acting together with the additional support surface 38 that is formed by the projection 56 and is facing inward in the radial direction R of the jet engine 1 and is also embodied so as to be substantially concentric to the central axis 16.

[0078] Here, the effective area 27 is formed by the part of the hook-shaped area 53 that surrounds the projection 56 and meshes with the groove 57 of the disc wheel 55, and acts together with the support surface 28 that is formed by the projection 56.

[0079] If the rotor blades 18 are already arranged inside the recesses 20 of the disc wheel 55, the securing segments 51 can be brought into mesh in a simple manner radially from the inside out with the grooves 25 of the rotor blades 18 on the one hand and with the projection 56 of the disc wheel 55 on the other hand.

[0080] For a play-free positioning of the securing segments 23, 51 inside the grooves 25 of the rotor blades 18 and inside the recess 24 of the disc wheel 17, or in the area of the projection 56 of the disc wheel 55, the securing segments 23 or 51 can be arranged in a pre-loaded manner by means of elastic deformation during mounting if the axial tolerances are designed correspondingly.

[0081] In the alternative embodiment shown in FIG. 4a, the securing device 22 again has multiple securing segments 51 that are substantially embodied in a structurally identical manner and that, with respect to their structure and their effective areas, are constructed in principle like the securing segments 51 that are shown in FIG. 4. As in the design variant shown in FIG. 3a in comparison to the embodiment in FIG. 3, the alternatively designed embodiment that can be seen in FIG. 4a is a modification of the embodiment according to FIG. 4 of a rotor blade 18 with a projection 33, which is part of a coating to form a cooling air channel outlet 34 that is configured as a microturbine. Just like in the embodiment according to FIG. 3a, the further support surface 32 is arranged in the area of the cooling air outlet 34, wherein the respective securing segments 51 are configured so as to be correspondingly shortened in their radial expansion.

[0082] What can be seen in FIG. 5 is a strongly simplified section of the securing device 50 as viewed in the axial direction A of the jet engine 1. The securing device 50 has substantially structurally identical securing segments 51, which are embodied with lateral surfaces that in particular extend in the radial direction R of the jet engine 1. Via the lateral surfaces, the securing segments 51 that are adjacent to each other in the circumferential direction U of the jet engine 1 act together.

[0083] As can be seen in FIG. 5 and FIG. 6, for mounting-related reasons the present securing device 50 has a securing segment 58 configured with two lateral surfaces 59, 60 that are embodied so as to be parallel to each other and that are oriented in the circumferential direction U of the jet engine 1. In this manner, the securing segment 58 can easily be brought into operative connection with the respectively adjacent securing segments 51 after all other securing segments 51 have been mounted.

[0084] In order to safely retain the securing segment 58 in the mounted position, two retaining appliances 61, 62 are provided in the present case. Via the respective retaining appliance 61, 62, the securing segment 58 can be connected in a captive manner with the securing segment 51 that is respectively adjacent in the circumferential direction U of the jet engine 1. In the present case, the retaining appliances 61, 62 are embodied as a wire or a sheet metal strip to be deformed that is respectively guided through a recess 63 or 64 of the securing segment 51 and a recess 65 or 66 of the securing segment 58.

[0085] In contrast to the embodiment according to FIG. 5 and FIG. 6 with numerous securing segments, in the embodiment shown in FIG. 7, a two-part ring is provided as a securing device 22 or 50, in which the securing device is configured in the kind of a snap ring with an end segment 58, wherein the gaps between the end segment 58 and the securing segment 51 that is remaining as a rest ring are oriented towards a central point of the ring and enclose an angle a inside a quadrant of a circle.

[0086] In every embodiment, any leakage in the gap area between the segments of the security device 50 can be minimized if the lateral surfaces 59, 60 of the individual segments 51, 58 axially overlap in the gap area, as can be seen in FIG. 8.

Parts List

[0087] 1 continuous-flow machine; jet engine [0088] 2 bypass channel [0089] 3 inflow area [0090] 4 fan [0091] 5 core flow channel [0092] 6 compressor appliance [0093] 7 burner [0094] 8 turbine appliance [0095] 9A, 9B rotor device (high-pressure) [0096] 10A, 10B, 10C rotor device (low-pressure) [0097] 11 engine shaft (high-pressure) [0098] 12 engine shaft (low-pressure) [0099] 13 stator device [0100] 14 first stage of the turbine appliance [0101] 16 central axis [0102] 17 disc wheel [0103] 18 rotor blade [0104] 19 blade root [0105] 20 recesses of the disc wheel [0106] 22 securing device [0107] 23, 23 securing segment [0108] 24 recess of the disc wheel [0109] 25 nut of the rotor blade [0110] 26 securing element; snap ring [0111] 27 effective area [0112] 28 first support surface [0113] 29 projection of the disc wheel [0114] 31 further effective area [0115] 32 further support surface [0116] 33, 33 projection of the rotor blade [0117] 34 cooling air outlet [0118] 35 additional effective area [0119] 38 additional, second support surface [0120] 40, 42 surface of the securing segment [0121] 41, 43 surface of the snap ring [0122] 45 support area [0123] 46 nose (support bar) [0124] 50 securing device [0125] 51, 51 securing segment [0126] 53 hook-shaped area [0127] 55 disc wheel [0128] 56 projection [0129] 57 nut [0130] 58 securing segment [0131] 59, 60 lateral surface of the securing segment [0132] 61, 62 retaining appliance [0133] 63, 64, 65, 66 recess [0134] A axial direction of the jet engine [0135] R radial direction of the jet engine [0136] U circumferential direction of the jet engine