US20120141253A1

US20120141253A1 - Turbomachine

Info

Publication number: US20120141253A1
Application number: US13/390,304
Authority: US
Inventors: Wilfried Weidmann
Original assignee: MTU Aero Engines GmbH
Current assignee: MTU Aero Engines AG
Priority date: 2009-08-14
Filing date: 2010-08-05
Publication date: 2012-06-07
Also published as: ES2669120T3; WO2011018072A3; WO2011018072A2; EP2464831A2; EP2464831B1; DE102009037620A1

Abstract

A turbomachine is disclosed. The turbomachine includes a housing and a guide blade ring. An outer shroud of the guide blade ring is divided into segments by joints, where the outer shroud is fastened to the housing by a first fastening element for absorbing axial force and a second fastening element independent of the first fastening element for absorbing circumferential force. The first fastening element and the second fastening elements enable play in a radial direction for the segments of the outer shroud.

Description

This application claims the priority of International Application No. PCT/DE2010/000927, filed Aug. 5, 2010, and German Patent Document No. 10 2009 037 620.8, filed Aug. 14, 2009, 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, comprising a housing and at least one guide blade ring, the outer shroud of which is divided into segments by joints.
Such a turbomachine is known from German Patent Document No. DE 198 07 247 C2 for example. The guide blade rings are fastened to the housing of the turbomachine with mounting pegs in the region of its outer shroud, wherein the segments of the guide blade ring are radially freely moveable in the region of the outer shroud. This type of mounting is also designated as spoke centering. In the process, the mounting pegs absorb all the forces transmitted by the guide blade ring onto the housing, in particular in the circumferential direction and axial direction.
The object of the invention is creating an improved fastening of a guide blade ring on the housing of the turbomachine, which enables a radial movability of the guide blade ring segments with a simultaneously lower load for the fastening elements.
According to the invention, a turbomachine of the type described at the outset is provided, wherein the outer shroud of the guide blade ring is fastened to the housing by means of a first fastening element for absorbing axial force and a second fastening element independent of the first fastening element for absorbing circumferential force and wherein the first and the second fastening elements enable play in the radial direction for the segments of the outer shroud.
In this way the axial force and the circumferential force are absorbed by means of separate, independent fastening elements. The load of the fastening elements is thereby reduced, and the fastening elements may be designed optimally for their respective functions. The axial force and circumferential force are orthogonal to each other, thereby enabling an independent absorption of the force, while, at the same time, forces in the radial direction are not absorbed by the fastening elements, thereby enabling play in the radial direction for the guide blade ring.
According to a preferred embodiment, the fastening element for absorbing circumferential force is formed by an essentially annular housing component that projects radially inwardly, wherein first slots and/or first noses are provided in the housing component, which mesh with second noses or second slots in a component of the outer shroud that projects radially outwardly and transmits circumferential force, such that the guide blade ring is fixed in the circumferential direction and the second nose or the second slot has play in the radial direction. This enables a simple geometry of the components transmitting circumferential force and therewith the smallest possible required installation space. Because of a symmetrical or asymmetrical arrangement of the noses and slots in the circumferential direction, the installation position of the guide blade ring can be determined.
It is possible for the fastening element for absorbing axial force to be arranged in the direction of force behind a component of the outer shroud that transmits axial force. This makes it possible to transmit compressive forces to the fastening element.
The axial force is preferably transmitted by means of several separate contact surfaces between the guide blade ring and the fastening element for absorbing axial force. In this way, it is possible to reduce the friction between the fastening element for absorbing axial force and the guide blade ring.
The fastening element for absorbing axial force is preferably annular and forms a positive connection with the housing. This enables, for example, a rotationally symmetrical embodiment of the fastening element for absorbing axial force.
The positive connection may be formed by a mounting extension on the housing and a groove in the annular fastening element for absorbing axial force.
The inside radius of the mounting extension is preferably larger than the outside radius of the outer shroud. This enables an assembly of the turbomachine in the axial direction.
According to another preferred embodiment, several fastening elements for absorbing axial force are provided, which are arranged in the direction of force in front of a component of the guide blade ring that transmits axial force. In this way, the axial force is transmitted by the guide blade ring by means of tensile forces to the fastening elements.
The fastening elements for absorbing axial force are preferably radially elastic elements. This guarantees the movability of the guide blade ring segments in the radial direction.
The fastening elements for absorbing axial force may be positively fastened to the housing and to the guide blade ring.
The preferably positive connection between the fastening element for absorbing axial force and the housing may be secured by a safety wire. In this way, it is possible to prevent an inadvertent detachment of the connection between the fastening element for absorbing axial force and the housing.
Additional features and advantages of the invention are disclosed in the following description and the following drawings to which reference is made.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a guide blade ring;

FIG. 2 is a sectional view of a turbomachine with two guide blades and one rotor blade;

FIG. 3 is a sectional view of a turbomachine with a radially movable guide blade;

FIG. 4 is a sectional view of a turbomachine according to a first embodiment of the invention;

FIG. 5 is a guide blade ring segment of the turbomachine according to FIG. 4; and

FIG. 6 is a turbomachine according to a second embodiment of the invention in a sectional view.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 3 depict a turbomachine 10 having a guide blade ring 12. The guide blade ring has an outer shroud 16, which is divided into individual segments 14 by joints. As indicated in FIG. 1 and FIG. 3 by the double-sided arrows, the segments 14 of the outer shroud 16 may move in the radial direction.
FIG. 2 shows a section of turbomachine 10 with two guide blade rings 12 and a rotor blade 18. The two guide blade rings 12 are connected by a honeycomb carrier 20.
FIG. 3 depicts a guide blade ring 12 between two rotor blades 18. The guide blade ring 12 and the honeycomb carrier 20 connected therewith are fastened in a housing 22 of the turbomachine 10, wherein the fastening (not shown in FIG. 3) for the segments 14 of the outer shroud 16 of the guide blade ring 12 enables play in the radial direction for the spoke-centered fastening. The outer shroud 16 of the guide blade ring 12 may move in this case in the radial direction between the radially inward and outward positions shown with dashed lines.
The various guide blades are preferably integrally connected to the inner shroud 17 of the guide blade ring 12.
FIG. 4 depicts a first embodiment of the fastening of the guide blade ring 12 on the housing 22 of the turbomachine 10. A fastening element 24 for absorbing circumferential force is an essentially annular housing component 26 that projects radially inwardly in which several slots are provided. The guide blade ring 12 has a component 28 that projects radially outwardly in the region of the outer shroud 16, which forms noses, which are positively connected to the slots in the housing component 26 and fix the guide blade ring 12 in the circumferential direction. Naturally, it is also possible for the housing component 26 to have noses which engage in slots in the component 28 of the guide blade ring 12 or for noses and slots to be provided both on the housing component 26 as well as on the component 28 of the guide blade ring 12, which mutually mesh to produce the positive connection.
A force acting on the guide blade ring 12 in the circumferential direction is transmitted by the component 28 by means of the meshing noses and slots to the housing component 26, which absorbs the circumferential force and thereby fixes the guide blade ring 12 in the housing 22 of the turbomachine 10 in the circumferential direction.
Forces acting in the axial direction are not absorbed by the fastening element 24 for absorbing circumferential force. The fastening element 24 for absorbing circumferential force allows on its own a movement of the guide blade ring 12 in one or both axial directions.
A fastening element 30 for absorbing axial force is arranged in the direction of force behind a component 32 of the guide blade ring 12 that transmits axial force. The direction of the axial force points from left to right in the depicted embodiment. In this arrangement, the axial force is transmitted as compressive force from the guide blade ring 12 by means of the component 32 that transmits axial force to the fastening element 30 for absorbing axial force.
The component 32 transmitting axial force has several separate contact surfaces 34, via which the axial force is transmitted between the guide blade ring 12 and the fastening element 30 for absorbing axial force. FIG. 5 shows a segment 14 of the shroud 16 of the guide blade ring 12, which has a contact surface 34 on each of its ends lying in the circumferential direction. Naturally, it is also possible for the contact surface 34 to extend over the entire circumference of the guide blade ring 12.
A special surface structure or a special coating, for example an armoring, may be provided for the contact surfaces 34 in order to keep the friction between guide blade ring 12 and the fastening element 30 for absorbing axial force as low as possible.
The fastening element 30 for absorbing axial force, which is slotted for mounting on the circumference, is annular and has a groove running in the circumferential direction on its outside radius, the groove being used to positively connect it to a mounting extension 36, which is formed on the housing 22. The inside radius of the mounting extension 36 is larger than the outside radius of the guide blade ring 12. In this way, the guide blade ring 12 is inserted in the axial direction into the closed housing 22 during assembly of the turbomachine 10.
During assembly of the turbomachine 10, after insertion of the guide blade ring 12 into the housing 22, the annular fastening element 30 for absorbing axial force, which is slotted for mounting on the circumference, is inserted on the mounting extension 36 of the housing 22, wherein the mounting extension 36 positively engages in the groove of the fastening element 30.
The inside radius of the fastening element 30 for absorbing axial force is smaller than the outside radius of the guide blade ring 12. In this way, the guide blade ring 12 is adjacent with the contact surfaces 34 to the fastening element 30 for absorbing axial force and the guide blade ring 12 is fixed in its axial position by means of the fastening element 30.
In the depicted embodiment, the component 32 that transmits axial force in the direction opposite from the axial force is adjacent to the fastening element 24 for absorbing circumferential force. In this way, the axial position of the guide blade ring 12 is exactly defined by the two fastening elements 24, 30 for absorbing circumferential force and for absorbing axial force, wherein, because of the direction of the axial force acting during normal operation of the turbomachine, the axial force is absorbed only by the fastening element 30 for absorbing axial force.
The two fastening elements 24, 30 for absorbing circumferential force and for absorbing axial force together form a guide for the components 28, 32 of the segment 14 of the outer shroud 16 of the guide blade ring 12, which enables a movement of the segment 14 in the radial direction.
The positive connection between the fastening element 30 for absorbing axial force and the mounting extension 36 of the housing 22 is secured by a safety wire 38. It is also possible for the fastening element 30 for absorbing axial force to be secured directly on the housing 22 by means of the safety wire 38.
A second embodiment of the fastening element 30 for absorbing axial force is depicted in FIG. 6. The fastening element 30 for absorbing axial force in this embodiment is arranged in the direction of force in front of a component 32 of the guide blade ring 12 that transmits axial force, whereby tensile forces may be transmitted between the component 32 transmitting axial force and the fastening element 30 for absorbing axial force.
One or more fastening elements 30 for absorbing axial force are provided for each segment 14 of the outer shroud of the guide blade ring 12. The fastening elements 30 are positively fastened to the housing 22 and to the guide blade ring 12. The positive connection to the fastening element 30 is secured on the housing 22 by means of a safety wire 38. The positive connection between the fastening element 30 and the guide blade ring 12 is secured by a clamp 40, which may be part of the honeycomb carrier 20 or a separate part.
The fastening elements 30 for absorbing axial force are radially elastic elements. The end of the fastening element 30 for absorbing axial force that is fastened to the guide blade ring 12 may move along a circular path around the end of the fastening element 30 fastened to the housing 22, wherein, in the case of small angles, the movement takes place in the radial direction in an approximately linear manner.
It is possible for the fastening elements 30 for absorbing axial force to be completely separate components. Alternatively, several and in particular all fastening elements 30 may be connected with one another on the end fastened to the housing 22, thereby forming an essentially annular fastening element 30 having several radially elastic extensions, each of which is fastened on its end to the guide blade ring 12.
In this embodiment, an essentially frictionless radial movement of the segments 14 of the guide blade ring 12 is possible independent of the axial force. Because no fastening elements 24, 30 are arranged in the direction of force behind the guide blade ring, a simple assembly in the axial direction is possible.
The housing component 26 that projects radially inwardly, which forms the fastening element 24 for absorbing circumferential force, as well as the component 28 of the guide blade ring 12 that transmits circumferential force is analogous in terms of design and function to the embodiment described in FIG. 4.

Claims

1.-11. (canceled)

12. A turbomachine, comprising:

a housing;

a guide blade ring, wherein an outer shroud of the guide blade ring is divided into segments by respective joints;

a first fastening element; and

a second fastening element;

wherein the outer shroud is fastened to the housing by the first fastening element and the second fastening element;

wherein an axial force is absorbable by the first fastening element, wherein a circumferential force is absorbable by the second fastening element, and wherein a movement in a radial direction for a segment of the outer shroud is enableable by the first fastening element and the second fastening element.

13. The turbomachine according to claim 12, wherein the second fastening element is an annular housing component that projects radially inwardly, wherein the housing component includes a first slot and/or a first nose which meshes with a second nose and/or a second slot, respectively, in a component of the outer shroud that projects radially outwardly.

14. The turbomachine according to claim 12, wherein the first fastening element is disposed in a direction of axial force behind a component of the outer shroud that transmits axial force.

15. The turbomachine according to claim 14, wherein the axial force is transmitted by the component by several separate contact surfaces disposed between the guide blade ring and the first fastening element.

16. The turbomachine according to claim 12, wherein the first fastening element is annular and is positively connected with the housing.

17. The turbomachine according to claim 16, wherein a groove in the annular first fastening element is positively connected with a mounting extension on the housing.

18. The turbomachine according to claim 17, wherein an inside radius of the mounting extension is larger than an outside radius of the outer shroud.

19. The turbomachine according to claim 12, wherein the first fastening element is disposed in a direction of axial force in front of a component of the guide blade ring that transmits axial force.

20. The turbomachine according to claim 19, wherein the first fastening element is radially elastic.

21. The turbomachine according to claim 19, wherein the first fastening element is positively fastened to the housing and to the guide blade ring.

22. The turbomachine according to claim 16, wherein the positive connection is secured by a safety wire.

23. The turbomachine according to claim 12, wherein the turbomachine is a gas turbine.

24. The turbomachine according to claim 12, wherein a movement of the guide blade ring in an axial direction is enableable by the second fastening element.

25. A method for absorbing forces in a turbomachine, wherein the turbomachine comprises:

a housing;

a first fastening element; and

a second fastening element;

and comprising the steps of;

absorbing an axial force by the first fastening element;

absorbing a circumferential force by the second fastening element; and

radially moving a segment of the outer shroud.