U.S. patent application number 11/632332 was filed with the patent office on 2008-10-23 for seal arrangement and method for manufacturing a sealing body for a seal arrangement.
This patent application is currently assigned to MTU Aero engines GmbH. Invention is credited to Horst Pillhoefer.
Application Number | 20080258404 11/632332 |
Document ID | / |
Family ID | 35094183 |
Filed Date | 2008-10-23 |
United States Patent
Application |
20080258404 |
Kind Code |
A1 |
Pillhoefer; Horst |
October 23, 2008 |
Seal Arrangement and Method for Manufacturing a Sealing Body for a
Seal Arrangement
Abstract
A seal arrangement and a method for manufacturing a sealing body
for a seal arrangement for a turbine engine is disclosed. The seal
arrangement seals a gap between a rotor and a stator, and has at
least one first seal body preferably assigned to the stator and at
least one blade-shaped second seal body preferably assigned to the
rotor which co-acts with the or each first seal body. The or each
first seal body has a main body and a porous wear component, where
the main body and the wear component have a graduated material
composition.
Inventors: |
Pillhoefer; Horst;
(Roehrmoos, DE) |
Correspondence
Address: |
CROWELL & MORING LLP;INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
MTU Aero engines GmbH
Munich
DE
|
Family ID: |
35094183 |
Appl. No.: |
11/632332 |
Filed: |
July 5, 2005 |
PCT Filed: |
July 5, 2005 |
PCT NO: |
PCT/DE2005/001177 |
371 Date: |
December 6, 2007 |
Current U.S.
Class: |
277/415 ;
29/428 |
Current CPC
Class: |
C23C 10/02 20130101;
F05D 2230/22 20130101; F01D 11/02 20130101; F01D 11/122 20130101;
F05D 2240/55 20130101; F05D 2300/121 20130101; C23C 26/02 20130101;
F01D 5/225 20130101; Y10T 29/49826 20150115; F05D 2300/132
20130101 |
Class at
Publication: |
277/415 ;
29/428 |
International
Class: |
F01D 11/12 20060101
F01D011/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2004 |
DE |
10 2004 034 312.8 |
Claims
1-15. (canceled)
16. A seal arrangement for a turbine engine to seal a gap between a
rotor and a stator, having a first sealing body assigned to the
stator and having a blade-shaped second sealing body assigned to
the rotor co-acting with the first sealing body, wherein the first
sealing body has a main body and a porous wear component and
wherein the main body and the wear component have a graduated
material composition.
17. The seal arrangement according to claim 16, wherein the main
body and the wear element consist of a ferrous based alloy or a
nickel based alloy which have an alloy gradient in a region of
their surfaces or edge zones with respect to aluminum (Al) and/or
chromium (Cr).
18. The seal arrangement according to claim 16, wherein the sealing
body and the wear component have an aluminum content of 15% to 35%
by weight in a surface area or an edge zone.
19. The seal arrangement according to claim 16, wherein the main
body and the wear component have a chromium content of 15% to 35%
by weight in a surface area or an edge zone.
20. The seal arrangement according to claim 16, wherein the wear
component is configured as a honeycomb sealing body.
21. The seal arrangement according to claim 16, wherein the wear
component is configured as a porous material layer.
22. The seal arrangement according to claim 21, wherein the wear
component is configured as a powder metal sintered body.
23. The seal arrangement according to claim 16, wherein the
blade-shaped second sealing body is configured as a seal fin from a
solid metal material.
24. A turbine engine having at least one seal arrangement according
to claim 16.
25. A gas turbine aero engine having at least one seal arrangement
according to claim 16.
26. A method for manufacturing a sealing body for a seal
arrangement, wherein the sealing body has a main body and a porous
wear component, comprising the steps of: preparation of the main
body; preparation of the porous wear component; bonding the main
body and the porous wear component; and calorizing and/or
chromizing of the bonded main body and porous wear component.
27. The method according to claim 26, wherein the main body and the
porous wear component are prepared from a ferrous based alloy or a
nickel based alloy.
28. The method according to claim 26, wherein the main body and the
porous wear component are bonded by soldering.
29. The method according to claim 28, wherein the main body and the
porous wear component are bonded by high-temperature soldering
under vacuum.
30. The method according to claim 26, wherein the main body and the
porous wear component are bonded by diffusion bonding.
31. The method according to claim 26, wherein the calorizing and/or
chromizing is carried out through a CVD process.
32. The method according to claim 26, wherein a layer of 40 .mu.m
to 100 .mu.m is created on the main body and a layer of 20 .mu.m to
60 .mu.m is created on the porous wear component in the calorizing
and/or chromizing step.
33. A seal arrangement for a turbine engine, comprising: a first
sealing body; and a blade-shaped second sealing body engageable
with the first sealing body; wherein the first sealing body
includes a main body and a porous wear component and wherein the
main body and the porous wear component have a graduated material
composition in a surface area that includes a ferrous alloy or a
nickel based alloy, and aluminum and/or chromium in a range of
15-35% by weight.
34. The seal arrangement according to claim 33, wherein the main
body has a graduated material composition coating thickness of
between 40 .mu.m-100 .mu.m on the surface area and the porous wear
component has a graduated material composition coating thickness of
between 20 .mu.m-60 .mu.m on the surface area.
35. A method for manufacturing a sealing body for a seal
arrangement, comprising the steps of: bonding a main body of the
sealing body to a porous wear component of the sealing body; and
calorizing and/or chromizing of the bonded main body and the porous
wear component such that a graduated material composition results
in a surface area of the bonded main body and the porous wear
component that includes a ferrous alloy or a nickel based alloy,
and aluminum and/or chromium in a range of 15-35% by weight.
Description
[0001] This application claims the priority of International
Application No. PCT/DE2005/001177, filed Jul. 5, 2005, and German
Patent Document No. 10 2004 034 312.8, filed Jul. 15, 2004, the
disclosures of which are expressly incorporated by reference
herein.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The invention relates to a seal arrangement and a method for
manufacturing a sealing body for a seal arrangement. The invention
further relates to a turbine engine and a gas turbine.
[0003] Gas turbines consist of several subassemblies, for example,
of at least a compressor, a combustion chamber and at least one
turbine. The or each compressor as well as the or each turbine has
a rotor which rotates relative to a stationary stator. In the case
of the stator, it is specifically a stationary housing to which
stationary guide vanes are assigned. Rotor blades are assigned to
the rotor which rotate together with the rotor relative to the
stationary guide vanes and the stationary housing.
[0004] To optimize the efficiency and thus to increase the power of
gas turbines, it is important to optimize all components and
subsystems. This includes the seal arrangements to minimize leakage
flow between the rotating rotor and the stationary stator. In
particular, a gap between radially inner ends of the fixed guide
vanes and the rotating rotor must be sealed. A seal arrangement to
seal the gap between the radially inner ends of the stationary
guide vanes and the rotating rotor is designated as an inner air
seal. A further gap to be sealed is located, for example, between
the radially outer end of the rotating rotor blades and the
stationary housing. A seal arrangement for sealing the gap between
the radially outer ends of the rotating rotor blades and the
housing is designated as an outer air seal.
[0005] It is already known from the prior art to configure seal
arrangements for providing an inner air seal or an outer air seal
as well as labyrinth seals, where such labyrinth seals are formed
by a first, porous sealing body and a blade-shaped second sealing
body co-acting with the first sealing body. The first porous
sealing body can, for example, be configured as a honeycomb sealing
body. It is also already known to configure the first sealing body
as a porous layer of material. The blade-shaped second sealing body
which co-acts with the first sealing body is also designated as a
seal fin. The seal fins are preferably assigned to the rotor or
rotating rotor blades in the area of an outer shroud of the blades.
The porous sealing body is, on the other hand, preferably assigned
to the housing or the stationary guide vanes in the area of an
inner shroud of the guide vanes.
[0006] Labyrinth seal systems known from the prior art are not
suitable for high temperatures that are consistently above
500.degree. C., since they are exposed to great wear at high
operating temperatures, for example from oxidation. Furthermore,
they are subject to vibrational load or deformation load. Labyrinth
seals known from the prior art consequently have a limited
operating life at temperatures of more than 500.degree. C. However,
due to the increasing improvements in gas turbines, higher
operating temperatures are found more frequently within the
turbines so that the labyrinth seals known from the prior art must
be improved.
[0007] With this as the starting point, the problem underlying the
present invention is to create a novel seal arrangement and a
method of manufacturing a sealing body for a seal arrangement.
[0008] In accordance with the invention the or each first sealing
body has a main body and a porous wear component wherein the main
body and the wear component have a graduated material
composition.
[0009] In the sense of the present invention, a seal arrangement is
provided in which the porous sealing body consists of a main body
and a porous wear component, wherein the main body and the porous
wear component have a graduated material composition. The
preference is for the main body and the porous wear component to be
graduated in their surface area with respect to aluminum and/or
chromium. As a result, the oxidation resistance of the wear
component and the main body is clearly improved so that the seal
arrangements can be used at temperatures of more than 600.degree.
C. Furthermore, the rigidity of the part is increased and at the
same time the ductility of the porous wear component is
preserved.
[0010] In accordance with an advantageous enhancement of the
invention, the main body and the wear component have an aluminum
content of 15% to 35% by weight in the area of their surfaces or
edge zones.
[0011] The method comprises at least the following steps: a)
preparation of a main body; b) preparation of a porous wear
component; c) bonding the main body and the wear component; d)
calorizing and/or chromizing the main body and wear component which
have been bonded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Preferred enhancements of the invention derive from the
following description. An embodiment of the invention is explained
more exactly using the drawings, without being restricted
thereto.
[0013] FIG. 1 shows a schematized section from a seal arrangement
in accordance with the invention;
[0014] FIG. 2 shows a detail of the seal arrangement from FIG.
1;
[0015] FIG. 3 shows an alternative detail of the seal arrangement
from FIG. 1; and
[0016] FIG. 4 shows a schematized section from a further seal
arrangement in accordance with the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0017] In what follows, the present invention is described in
greater detail with reference to FIGS. 1 to 4.
[0018] FIG. 1 shows a seal arrangement 10 in accordance with a
first embodiment of the invention to seal a gap 11 between a rotor
12 and a stator 13 of a gas turbine, in particular a low-pressure
turbine of an aero engine. The seal arrangement shown in FIG. 1 may
be, for example, an outer air seal, wherein the stator 13 is formed
by a housing and the rotor 12 by rotating rotor blades, that is to
say an outer shroud for the rotor blades.
[0019] The seal arrangement of FIG. 1 is formed by a first sealing
body 14 assigned to the stator 13 and a second sealing body 15
co-acting with the first sealing body 14. FIG. 2 shows the first
sealing body 14 in a separate view.
[0020] The first sealing body 14 is formed by a carrier or main
body 16 and a porous wear component 17. The main body 16 and the
wear component 17 are solidly bonded, by high-temperature soldering
for example. In the embodiment from FIGS. 1 and 2, the porous wear
component 17 is configured as a honeycomb sealing body. FIG. 3
shows an alternative configuration of the first sealing body 14, in
which the porous wear component 17 is composed of a porous material
layer, specifically a powder metal sintered body.
[0021] In the sense of the present invention, the main body 16 and
the porous wear component 17 are both formed from a ferrous alloy
or a nickel based alloy which have a graduated material composition
in the area of their surfaces, or edge zones, with respect to
aluminum and/or chromium. The aluminum content and/or chromium
content in the area of the surface, or edge zone, of main body 16
and wear component 17 lies in a range between 15 and 35% by weight.
As a result, an intermetallic alloy compound is created in the area
of the surfaces or edge zones which exhibits optimized oxidation
resistance for applications at temperatures above 600.degree.
C.
[0022] FIG. 4 shows a further seal arrangement according to the
invention 18 which is essentially the same as the embodiment from
FIG. 1. So identical reference numerals are used for identical
assemblies. The seal arrangement 18 from FIG. 4 differs from the
seal arrangement 10 in accordance with FIG. 1 only in that the wear
component 17 has a stepped configuration and co-acts with two
second blade-shaped sealing bodies 15 which have different radial
extensions. With respect to the remaining details, reference can be
made to the above explanations.
[0023] To manufacture the first sealing body 14 for the seal
arrangements shown in the drawings, the process begins with the
preparation of a main body 16 and a porous wear component 17 for
the seal arrangements, wherein the main body and the wear element
are made from a ferrous based alloy or a nickel based alloy. In the
case of the wear component 17, it can be a honeycomb sealing body
or a sealing body of a layer of porous material, specifically a
powder metal sintered body.
[0024] Following this, the wear component 17 and the main body 16
are solidly bonded together. Bonding the main body 16 to the wear
component 17 is preferably performed by means of high-temperature
soldering, in which the soldering temperature is higher than
approximately 80% of the melting temperature of the base material
of the wear component 17 and the main body 16 to be bonded. If, for
example, a wear component 17 of Hastelloy is used in a honeycomb
structure, the soldering temperature can be 1180.degree. C.
Alternatively, the bonding of wear component 17 and main body 16
can also be carried out by diffusion bonding.
[0025] After bonding the main body 16 to the porous wear component
17, the bonded components are calorized and/or chromized. The
calorizing and/or chromizing is preferably performed with the aid
of a Chemical Vapor Deposition (CVD) process, in which an alloy
gradient with respect to aluminum and/or chromium results on the
surface or in the edge zone of main body 16 and porous wear
component 17 through calorizing and/or chromizing. Calorizing is
preferably carried out at 1050.degree. C. over a 4 hour period.
[0026] During the calorizing and/or chromizing, a coating thickness
of 40 .mu.m to 100 .mu.m, preferably 80 .mu.m is created on the
carrier or main body 16; on the porous wear component on the other
hand, a coating thickness of 20 .mu.m to 60 .mu.m, preferably of 40
.mu.m is created. An aluminum content and/or chromium content of
15% to 35% by weight, preferably of 30% by weight, is thereby
created on the surface or on the edge zone of wear component 17 and
main body 16. Furthermore, the oxidation resistance of the sealing
body 14 is thereby improved and the rigidity of the wear component
17 is increased without negatively influencing its ductility.
[0027] The seal arrangement in accordance with the invention is
preferably used in turbine engines, gas turbines or aero engines.
It is especially suitable for use in a low-pressure compressor of
an aero engine.
* * * * *