US20090028712A1

US20090028712A1 - Turbomachine having axial rotor blade securing

Info

Publication number: US20090028712A1
Application number: US12/096,759
Authority: US
Inventors: Wilfried Weidmann; Moritz Wirth
Original assignee: MTU Aero Engines GmbH
Current assignee: MTU Aero Engines AG
Priority date: 2005-12-10
Filing date: 2006-12-05
Publication date: 2009-01-29
Also published as: EP1957755A1; WO2007065411A1; DE102005059084A1

Abstract

A rotor of a turbine machine having several rotor blade rings positioned in succession in the axial direction, is disclosed. Each rotor blade ring has a rotor base body with several rotor blades anchored by blade footings in axial grooves of the rotor base body that extend essentially in the axial direction and, in their anchored position in the rotor base body, are secured against displacement in the axial direction. The rotor blades of at least one rotor blade ring have hook-like securing elements, which, in the anchored position on a low-pressure side of the rotor blade ring, abut the rotor base body. The hook-like securing elements, between the rotor base body and a sealing element, which extends between the rotor base body and a rotor base body of a rotor blade ring that connects on the low-pressure side, are fixed in the axial direction on both sides.

Description

This application claims the priority of International Application No. PCT/DE2006/002150, filed Dec. 5, 2006, and German Patent Document No. 10 2005 059 084.5, filed Dec. 10, 2005, the disclosures of which are expressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a turbomachine, in particular a gas turbine.
Turbomachines, in particular gas turbines, have several rotor blade rings positioned in succession in the axial direction both in the region of a turbine as well as in the region of a compressor, wherein each rotor blade ring has in particular a disk-shaped rotor base body and several rotor blades rotating with the rotor base body. The present invention relates to a turbomachine, in particular a gas turbine, in which the rotor blades of the rotor blade rings are fastened by their blade footings in grooves, which run essentially in the axial direction of the rotor base body, i.e., in so-called axial grooves. In this case, the rotor blades of the rotor blade rings must be secured, in their assembly position or in their anchored position, in the axial grooves of the rotor base body against displacement in the axial direction.
In practice, normally so-called wire securing devices are used to axially secure the rotor blades of a rotor blade ring that are fastened in axial grooves of a rotor base body via their blade footings. In the case of these types of wire securing devices, a wire-shaped securing element is threaded into a groove, which is embodied between the blade footings of the rotor blades and the rotor base body in order to thereby secure the rotor blades against displacement in the axial direction. A separate wire-shaped securing element is normally used in this process for each rotor blade, which results in an intricate assembly of the wire securing devices. In addition, wire securing devices are subject to tolerances.
So-called securing plates, which are also designated as closing plates or locking plates, are used in the case of another variation known from the prior art for axially securing rotor blades. These types of securing plates are guided into a ring groove of the rotor base body as well as into a ring groove of the rotor blades anchored in the rotor base body. These types of securing plates increase the load on the blade footing of the rotor blades and therefore the boundary stress that occurs.
Starting herefrom, the present invention is based on the objective of creating a novel turbomachine.
According to the invention, the rotor blades of at least one rotor blade ring have hook-like securing elements, which, in the anchored position on a low-pressure side of the rotor blade ring, abut the rotor base body of same, wherein the hook-like securing elements between the rotor base body of the rotor blade ring and a sealing element, which extends between the rotor base body and a rotor base body of a rotor blade ring that connects on the low-pressure side, are fixed in the axial direction on both sides.
In terms of the invention at hand, the rotor blades that must be secured in their axial position have hook-like securing elements, which are fixed between the rotor base body of the respective rotor blade ring and the sealing element by clamping on both sides. This provides for completely novel securing of the rotor blades that are guided into axial grooves against unintended displacement in the axial direction, which is characterized by simple assembly and disassembly, and with whose assistance leakage flows in the radially inner region of the rotor blade rings can also be minimized. In addition, the inventive axial securing of the rotor blades does not increase the stress acting on the blade footings of same.
The sealing element is preferably fastened bayonet-like via a section adjacent to the hook-like securing elements on the rotor base body of the rotor blade ring, whose rotor blades must be secured against displacement in the axial direction, wherein this section of the sealing element fixes the hook-like securing elements of the rotor blades in the axial direction on both sides.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred developments of the invention are yielded from the following description. Without being limited hereto, exemplary embodiments of the invention are explained in greater detail on the basis of the drawings. The drawings show:

FIG. 1 is a section of an inventive gas turbine according to a first exemplary embodiment of the invention; and

FIG. 2 is a section of an inventive gas turbine according to a second exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a section of a turbine 10 of an inventive gas turbine, namely of a gas turbine aircraft engine, in the region of two rotating rotor blade rings 11, 12 arranged in succession in the axial direction, wherein a stationary guide vane ring 13 is arranged between the two depicted rotor blade rings 11, 12. The turbine 10 is flowed through in the axial direction in the direction of the arrow 14 depicted in FIG. 1.
Each of the two rotor blade rings 11, 12 depicted in FIG. 1 has a preferably disk-shaped rotor base body 15 or 16, wherein rotor blades 17 or 18 of the rotor blade rings 11 or 12 are fastened or anchored by blade footings 19 or 20 in so-called axial grooves of the respective rotor base body 15 or 16. The axial grooves of the rotor base bodies 15 or 16, in which the rotor blades 17 or 18 are anchored via their blade footings 19 or 20, run essentially in the axial direction of the turbine 10. Blade pans 21, 22 attach radially outside to the blade footings 19, 20 of the rotor blades 17, 18, wherein blade footing platforms 23, 24 are embodied between the blade footings 19, 20 and blade pans 21, 22 of the rotor blades 17, 18.
The guide vane ring 13 positioned between the two rotor blade rings 11, 12 is comprised of several stationary guide vanes 25, wherein a platform 27 is embodied on a radial inner end of the blade pans 26 of the stationary guide vanes 25, on which platform a seal 28 in the form of a brush seal is fastened in the exemplary embodiment in FIG. 1, wherein other seal types can also be used. According to FIG. 1, the stator-side seal 28 cooperates with a rotor-side sealing element 29 positioned between the two rotor blade rings 11, 12 in order to thereby seal a radial inner gap between the rotating rotor blade rings 11, 12 and the stationary guide vane ring 13.
To secure the rotor blades 17 of the rotor blade ring 11 in their anchored position in the axial grooves of the corresponding rotor base body 15 and consequently to secure the same against undesired displacement in the axial direction, the rotor blades 17 of the rotor blade ring 11 are assigned hook-like securing elements 30, which, in the anchored position on a low-pressure side of the rotor blade ring 11, abut the rotor base body 15 of same. As FIG. 1 shows, the securing elements 30 are assigned to the blade footings 19 of the rotor blades 17 and abut the rotor base body 15 of the rotor blade ring 11 with a radially inner section 31.
The hook-like securing elements 30 for axially securing the rotor blades 11 between the rotor base body 15 of the rotor blade ring 11 and the sealing element 29, which extends between the rotor base body 15 of the rotor blade ring 11 and the rotor base body 16 of a rotor blade ring 12 that connects on the low-pressure side, are fixed in the axial direction on both sides. According to FIG. 1, the hook-like securing elements 30 between the rotor base body 15 of the rotor blade ring 11, which secures the rotor blades 17 with respect to their axial position, and the rotor-side sealing element 29 are clamped on both sides.
In the exemplary embodiment in FIG. 1, the rotor-side sealing element 29 is fastened bayonet-like via a section 32, which is positioned adjacent to the hook-like securing elements 30 of the rotor blades 17, on the rotor base body 15 of the rotor blade ring 11. The section 32 of the sealing element 29 has a nose-like projection 33, which can be inserted via an opening (not shown) into a groove 34 of the rotor base body 15 in the axial direction. After inserting the projection 33 of the sealing element 29 via the opening into the groove 34 of the rotor base body 15, the sealing element 29 can be rotated in the circumferential direction in order to thereby fasten the bayonet-like fastening of the sealing element 29 on the rotor base body 15 of the rotor blade ring 11, whose rotor blades 17 must be secured against displacement in the axial direction. When rotating in the circumferential direction for the bayonet-like fastening of the sealing element 29 on the rotor base body 15 of the rotor blade ring 11, the hook-like securing elements 30 between the rotor base body 15 and the sealing element 29 are clamped in order to thereby fix the rotor blades 17 and 18 on both sides. The section 32 of the sealing element 29, which is used for the bayonet-like fastening of the sealing element 29 on the rotor base body 15 of the rotor blade ring 11, fixes the rotor blades 11 via the hook-like securing elements 30 in the axial direction on both sides.
FIG. 2 shows another exemplary embodiment of an inventive gas turbine, wherein the exemplary embodiment in FIG. 2 also depicts a section of a turbine 35. The exemplary embodiment in FIG. 2 corresponds in terms of many details to the exemplary embodiment in FIG. 1. As a result, in order to avoid unnecessary repetition, the same reference numerals are used for the same components. In the following, only the details of the exemplary embodiment in FIG. 2 that differ from the exemplary embodiment in FIG. 1 will be addressed.
In the exemplary embodiment in FIG. 2, the rotor blades 17 have hook-like securing elements 30 just like the exemplary embodiment in FIG. 1, which, in the anchored position on a low-pressure side of the rotor blade ring 11 abut the rotor base body 15 of same. The hook-like securing elements 30 in this case are again fixed between the rotor base body 15 of the rotor blade ring 11 and the sealing element 29 in the axial direction on both sides, wherein the sealing element 29 extends between the rotor base body 15 of the rotor blade ring 11, whose rotor blades must be secured against displacement in the axial direction, and the rotor base body 16 of a rotor blade ring 12 that connects on the low-pressure side.
In the exemplary embodiment in FIG. 2, the sealing element 29 is not connected bayonet-like to the rotor base body 15 of the rotor blade ring 11 as in the exemplary embodiment in FIG. 1, rather a projection 36 of the sealing element 29 is fastened via screws between two flanges 37 and 38 of the rotor base bodies 15 and 16 that are positioned in succession in the axial direction. A section 39 of the sealing element 29 that connects to the projection 36 is used for fixing the hook-like securing elements 30 on both sides between the rotor base body 15 and the sealing element 29 in order to thereby prevent unintended displacement of the rotor blades 17 of the rotor blade ring 11 in the axial direction.
In terms of the present invention, rotor blades of rotor blade rings inserted into axial grooves are secured against undesired axial displacement in that hook-like securing elements assigned to the blade footings of the rotor blades are fixed between the rotor base body of the rotor blade ring and a rotor-side sealing element of a so-called inner-air seal, namely in the axial direction on both sides, wherein all blades of two adjacent rotor blade rings 11 and 12 are secured axially by a component 29. In the process, the sealing element is fastened preferably bayonet-like on the corresponding rotor base body. The advantage of the invention is that the rotor blades can be assembled or disassembled relatively simply from the rotor base body. All rotor blades of a rotor blade ring in this case can be fixed jointly via a sealing element in the axial direction.

Claims

1-7. (canceled)

8. A turbomachine having several rotor blade rings positioned in succession in an axial direction that are assigned to a turbine or a compressor, wherein each rotor blade ring has a rotor base body with several rotor blades, and wherein the rotor blades of a rotor blade ring are anchored by respective blade footings in axial grooves of a rotor base body of the rotor blade ring that extend in the axial direction and, in an anchored position in the rotor base body, are secured against displacement in the axial direction, and wherein the rotor blades of at least one rotor blade ring have a hook-like securing element, which, in the anchored position on a low-pressure side of the rotor blade ring, abut the rotor base body, wherein the hook-like securing element between the rotor base body of the rotor blade ring and a sealing element, which extends between the rotor base body and a rotor base body of a rotor blade ring that connects on the low-pressure side, are fixed in the axial direction on both sides.

9. The turbomachine according to claim 8, wherein the hook-like securing element between the rotor base body of the rotor blade ring and the sealing element is clamped in the axial direction on both sides.

10. The turbomachine according to claim 8, wherein the sealing element is fastened bayonet-like via a section adjacent to the hook-like securing element on the rotor base body of the rotor blade ring.

11. The turbomachine according to claim 10, wherein the section of the sealing element fixes the hook-like securing element of the rotor blade in the axial direction on both sides.

12. The turbomachine according to claim 10, wherein the section of the sealing element has a projection, which is insertable via an opening into a groove of the rotor base body in the axial direction, wherein the sealing element is rotatable in a circumferential direction following the bayonet-like fastening of same.

13. The turbomachine according to claim 8, wherein the sealing element is fastened via a projection between a flange of the rotor base body and a flange of the rotor base body of the rotor blade ring that connects on the low-pressure side.

14. The turbomachine according to claim 13, wherein a section of the sealing element adjacent to the projection fixes the hook-like securing element of the rotor blades in the axial direction on both sides.

15. A turbomachine, comprising:

a rotor blade ring having a rotor blade and a rotor base body, wherein the rotor blade is anchored in an axial groove of the rotor base body;

and wherein the rotor blade includes a hook-like securing element which is secured between the rotor base body and a sealing element which extends between the rotor base body and a second rotor base body of a second rotor blade ring.

16. The turbomachine according to claim 15, wherein the hook-like securing element extends in a radially inward direction of the rotor blade ring.

17. The turbomachine according to claim 15, wherein the hook-like securing element is disposed on a low-pressure side of the rotor blade and wherein a portion of the hook-like securing element extends beyond a radially inner end of the rotor blade.

18. The turbomachine according to claim 15, wherein the sealing element includes a section that is fastened bayonet-like on the rotor base body.

19. The turbomachine according to claim 18, wherein the section abuts the hook-like securing element.

20. The turbomachine according to claim 18, wherein the section has a projection which is insertable into a groove of the rotor base body.

21. The turbomachine according to claim 15, wherein the sealing element includes a projection that is fastened between a flange of the rotor base body and a flange of the second rotor base body.

22. The turbomachine according to claim 15, further comprising a guide vane ring disposed between the rotor blade ring and the second rotor blade ring.

23. The turbomachine according to claim 22, wherein the guide vane ring includes a seal and wherein the sealing element engages with the seal.

24. The turbomachine according to claim 23, wherein the seal is a brush seal.

25. The turbomachine according to claim 23, wherein the seal seals a radial inner gap defined by the rotor blade rings and the guide vane ring.

26. The turbomachine according to claim 15, wherein the hook-like securing element which is secured between the rotor base body and a sealing element is fixed in an axial direction of the turbomachine.