U.S. patent application number 12/841317 was filed with the patent office on 2011-02-17 for fluid flow machine.
This patent application is currently assigned to MAN Diesel & Turbo SE. Invention is credited to Emil Aschenbruck, Michael Blaswich.
Application Number | 20110038718 12/841317 |
Document ID | / |
Family ID | 42989218 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110038718 |
Kind Code |
A1 |
Aschenbruck; Emil ; et
al. |
February 17, 2011 |
Fluid Flow Machine
Abstract
A fluid flow machine has a stator, a rotor which is supported so
as to be rotatable relative to the stator, and a brush seal which
seals a gap formed between the stator and rotor in a radial
direction to prevent the passage of fluid. The brush seal has a
brush holder and a plurality of sealing bristles, each of which has
a first end that is fastened to the brush holder and a second end
that contacts a sealing surface. The sealing surface is
rotationally displaceable relative to the second ends of the
respective sealing bristles. The sealing surface is formed by a
circumferential surface of an intermediate sleeve which is arranged
between the stator and rotor and which radially divides the
gap.
Inventors: |
Aschenbruck; Emil;
(Duisburg, DE) ; Blaswich; Michael; (Oberhausen,
DE) |
Correspondence
Address: |
COHEN, PONTANI, LIEBERMAN & PAVANE LLP
551 FIFTH AVENUE, SUITE 1210
NEW YORK
NY
10176
US
|
Assignee: |
MAN Diesel & Turbo SE
Oberhausen
DE
|
Family ID: |
42989218 |
Appl. No.: |
12/841317 |
Filed: |
July 22, 2010 |
Current U.S.
Class: |
415/173.1 |
Current CPC
Class: |
F01D 11/001 20130101;
F01D 11/02 20130101; F05D 2240/56 20130101; F01D 11/003 20130101;
F16J 15/3288 20130101 |
Class at
Publication: |
415/173.1 |
International
Class: |
F01D 11/08 20060101
F01D011/08 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 2009 |
DE |
10 2009 037 393.4 |
Claims
1. A fluid flow machine comprising a stator (10), a rotor (20)
supported so as to be rotatable relative to the stator (10), said
stator and rotor defining a gap (S) therebetween in a radial
direction (RR); a brush seal (50') for sealing said gap (S) between
said stator and said rotor to prevent a leakage of fluid, said the
brush seal comprising a brush holder (51) and a plurality of
sealing bristles (52); a sealing surface (D') in contact with said
sealing bristles; each sealing bristle having a first end fastened
to said brush holder (51) and a second end contacting said sealing
surface (D'); said sealing surface (D') being rotationally
displaceable relative to said second ends of said respective
sealing bristles (52); said sealing surface (D') being formed by a
circumferential surface of an intermediate sleeve arranged between
said stator (10) and said rotor (20) for radially dividing said gap
(S).
2. The fluid flow machine according to claim 1, wherein said
intermediate sleeve (60) divides said gap (S) radially into a first
gap portion adjoining said sealing surface (D') and a second gap
portion adjoining a circumferential surface of said intermediate
sleeve (60) remote of said sealing surface (D'), and wherein a
radial extension of said second gap portion is greater than
zero.
3. The fluid flow machine according to claim 1, additionally
comprising a flange mounting portion (62) at one of said stator and
said rotor and wherein said intermediate sleeve (60) comprises a
flange (62) for mounting said sleeve (60) at said flange mounting
portion (22) of one of said stator (10) and said rotor (20) so as
to be fixed with respect to rotation relative thereto.
4. The fluid flow machine according to claim 3, wherein said flange
(62) is detachably mounted at said flange mounting portion
(22).
5. The fluid flow machine according to claim 3, wherein said flange
(62) comprises an annular flange surface at an axial end thereof
and said flange mounting portion (22) comprises a mounting surface;
and wherein said flange (62) is arranged at an axial end of said
intermediate sleeve (60) so that said annular flange surface is
contacting said mounting surface of said flange mounting portion
(22) so as to be tight against fluid.
6. The fluid flow machine according to claim 1, wherein said
intermediate sleeve (60) comprises an outer circumferential surface
(61) and wherein said rotor (20) is formed by a shaft, and said
intermediate sleeve (60) is mounted on said rotor (20) so as to be
fixed with respect to rotation relative thereto so that said
sealing surface (D') is formed by an outer circumferential surface
(61) of said intermediate sleeve (60), and wherein said brush
holder (51) is arranged at said stator (10) so as to be fixed with
respect to rotation relative thereto.
7. The fluid flow machine according to claim 6, wherein said
intermediate sleeve (60) comprises an inner diameter and an inner
circumferential surface; and said shaft comprises an outer diameter
and an outer circumferential surface (21) and wherein said inner
diameter of said intermediate sleeve (60) is greater than said
outer diameter of said shaft so that an annular gap is formed
between said inner circumferential surface of said intermediate
sleeve (60) and said outer circumferential surface (21) of said
shaft.
8. The fluid flow machine according to claim 1, wherein said fluid
flow machine is a turbo machine.
9. The fluid flow machine according to claim 8, wherein said turbo
machine is one of a gas turbine and a turbo compressor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to a fluid flow machine
with a stator, a rotor which is supported so as to be rotatable
relative to the stator and a brush seal which seals the gap between
the stator and the rotor in the radial direction to prevent the
passage of fluid.
[0003] 2. Description of the Related Art
[0004] A fluid flow machine of the type mentioned above is known,
e.g., from EP 0 834 688 A1. An adjustable brush seal is known from
U.S. Pat. No. 6,435,514, the entire content of which is
incorporated herein by reference.
[0005] Fluid flow machines include, for example, propellers and
repellers, centrifugal pumps and turbo machinery of any kind such
as gas turbines, steam turbines and rotary compressors such as,
e.g., radial compressors and axial compressors.
[0006] The rotor in fluid flow machines such as turbo machines can
be sealed by means of labyrinth tip seals, mechanical seals or
brush seals to prevent the leakage of fluid. In brush seals,
sealing bristles (also known as brush wires) of the brush seal make
direct contact with the rotor of the turbo machine, this rotor
being constructed, e.g., as a shaft. The brush seal limits the
amount of work fluid, e.g., the amount of compressor air, flowing
out of a flow part of the turbo machine into a bearing periphery of
the turbo machine, for example.
[0007] FIGS. 1 and 2 show a prior art fluid flow machine 1 which is
constructed as a gas turbine. As can be seen from FIG. 1 and FIG.
2, the fluid flow machine 1 has a stator 10 which is constructed in
this instance as a gas turbine housing, a rotor 20 which is
supported so as to be rotatable relative to the stator 10 and which
is constructed in this instance as a shaft, rotational bearings 30,
40 which carry out the rotatable bearing support of the rotor 20 in
the stator 10, and two brush seals 50 which seal a gap S formed in
radial direction RR between the stator 10 and rotor 20 to prevent
the passage of fluid.
[0008] As can be seen particularly from FIG. 2, every brush seal 50
has a brush holder 51 and a plurality of sealing bristles 5, each
of which has a first end which is fastened to the brush holder 51
and a second end which contacts a sealing surface D which is formed
in this case by an outer circumferential surface 21 of the rotor
20, so that a sealing bristle-on-sealing surface contact zone is
formed. The sealing surface D is rotationally displaceable,
particularly rotatable in this case, relative to the second ends of
the respective sealing bristles 52.
[0009] During operation of the fluid flow machine 1, the relative
movement between the rotating rotor 20 and the brush seal 50, which
is static in this case, leads to heating of the sealing surface D
of the rotor 20 and sealing bristles 52 due to the friction between
the sealing bristles 52 and the outer circumferential surface 21 of
the rotor 20.
[0010] However, problems arise in this conventional seal in that an
uneven heating of the sealing surface D is brought about in the
absence of a state of true in the contact zone of the sealing
surface D and sealing bristles 52. This uneven heating can
exacerbate the out-of-true state and lead to a deformation of the
rotor 20 (manifesting itself in this case as sagging between the
rotational bearings 30 and 40 of the shaft) which impairs continued
operation of the fluid flow machine 1 owing to impermissibly strong
rotor vibrations.
[0011] It is an object of the invention to provide a fluid flow
machine in which the sealing bristle-on-sealing surface contact
zone is thermally decoupled in order to prevent a deformation in
the fluid flow machine which is brought about by introduced heat
and which impairs the operation of the fluid flow machine.
SUMMARY OF THE INVENTION
[0012] According to the present invention, a fluid flow machine has
a stator, a rotor which is supported so as to be rotatable relative
to the stator, and a brush seal which seals a gap formed between
the stator and rotor in a radial direction of the rotor to prevent
the passage of fluid. The brush seal has a brush holder and a
plurality of sealing bristles, each of which has a first end that
is fastened to the brush holder and a second end that contacts a
sealing surface so that a sealing bristle-on-sealing surface
contact zone is formed. The sealing surface is rotationally
displaceable relative to the second ends of the respective sealing
bristles.
[0013] The fluid flow machine according to the present invention is
characterized in that the sealing surface is formed by a
circumferential surface of an intermediate sleeve or intermediate
bushing which is arranged between the stator and rotor and which
radially divides the gap.
[0014] By moving the sealing surface to an intermediate sleeve, the
sealing bristle-on-sealing surface contact zone is thermally
decoupled so as to prevent a deformation in the fluid flow machine
which is brought about by introduced heat and which impairs the
operation of the fluid flow machine.
[0015] According to the present invention, the intermediate sleeve
is fastened either to a rotating part or to a stationary part of
the brush seal. This fastening is advantageously carried out in
such a way that, on the one hand, sufficient stability is achieved
and, on the other hand, a heat transfer between the intermediate
sleeve and the part to which the intermediate sleeve is fastened is
as small as possible. The small heat transfer can be achieved,
e.g., by means of the smallest possible contact surfaces and/or by
providing an insulating layer between the contact surfaces of the
intermediate sleeve and the part fastening the latter.
[0016] According to the present invention, the brush holder can be
arranged at the stator and the intermediate sleeve can be arranged
at the rotor so as to rotate along with the latter. In this case,
the circumferential surface of the intermediate sleeve forming the
sealing surface would be an outer circumferential surface. However,
it is also possible according to the invention that the brush
holder is arranged at the rotor and the intermediate sleeve is
arranged in a stationary manner at the stator so that the
circumferential surface of the intermediate sleeve forming the
sealing surface would be an inner circumferential surface in this
case. The respective solution can be determined depending on the
desired operating characteristics and design factors.
[0017] Further, according to the present invention, the rotor can
be formed, e.g., by a shaft rotating in a stator (e.g., in a
housing) and, e.g., by a housing rotating around a stator (e.g.,
around an axle). The respective solution can be determined
depending on the desired operating characteristics and the design
factors.
[0018] According to an embodiment of the invention, the
intermediate sleeve divides the gap radially into a first gap
portion adjoining the sealing surface and a second gap portion
adjoining a circumferential surface of the intermediate sleeve
remote of the sealing surface, wherein a radial extension of the
second gap portion is greater than zero.
[0019] In other words, there is an air gap between the intermediate
sleeve and the part (e.g., the rotor or the stator) fastening this
intermediate sleeve. This air gap advantageously ensures additional
thermal insulation between the intermediate sleeve and the part
fastening the same. This makes it even more difficult for heat to
transfer from the sealing surface and the part fastening the
intermediate sleeve so that a deformation of the part fastening the
intermediate sleeve that is brought about by introduced heat is
prevented in an even more reliable manner.
[0020] According to another embodiment of the invention, the
intermediate sleeve has a flange by means of which the intermediate
sleeve is mounted at a flange mounting portion of the stator or
rotor so as to be fixed with respect to rotation relative to
it.
[0021] This construction of the invention is advantageous
particularly with respect to ensuring the smallest possible contact
surfaces between the intermediate sleeve and the part (in this
case, particularly the stator or the rotor) fastening this
intermediate sleeve, while at the same time ensuring that the
fastening is sufficiently stable.
[0022] According to yet another embodiment of the present
invention, the flange is mounted at the flange mounting portion by
detachable fastening means. Such fastening means can be, for
example, screw connections, rivet connections, clamping
connections, etc. In particular, the detachable connection
facilitates the changing of worn intermediate sleeves, for
example.
[0023] Further, the flange connection makes it possible to
introduce a thermal insulation layer between the flange and the
flange mounting portion in a simple manner.
[0024] According to another embodiment of the invention, the flange
is arranged at an axial end of the intermediate sleeve so that the
flange has, at the axial end, an annular flange surface which
contacts a mounting surface of the flange mounting portion so as to
be tight against fluid.
[0025] This construction of the invention reliably ensures a seal
between the intermediate sleeve and the part fastening this
intermediate sleeve to prevent the passage of fluid.
[0026] According to another embodiment of the invention, the rotor
is formed by a shaft and the intermediate sleeve is mounted on the
rotor so as to be fixed with respect to rotation relative to it so
that the sealing surface is formed by an outer circumferential
surface of the intermediate sleeve, wherein the brush holder is
arranged at the stator so as to be fixed with respect to rotation
relative to it.
[0027] An embodiment of the invention of the kind mentioned above
can be produced in a particularly simple and dependably operating
manner.
[0028] According to yet another embodiment of the invention, an
inner diameter of the intermediate sleeve is greater than an outer
diameter of the shaft so that an annular gap is formed between an
inner circumferential surface of the intermediate sleeve and an
outer circumferential surface of the shaft.
[0029] This construction of the invention achieves a thermally
insulating air gap between the intermediate sleeve and the part
fastening this intermediate sleeve in a simple and robust manner,
this part being formed in this case by the rotor which is
constructed as a shaft.
[0030] According to embodiment forms of the present invention, the
fluid flow machine is a turbo machine, particularly a gas turbine
or a turbo compressor.
[0031] The various features of novelty which characterize the
invention are pointed out with particularity in the claims annexed
to and forming a part of the disclosure. For a better understanding
of the invention, its operating advantages, and specific objects
attained by its use, reference should be had to the drawing and
descriptive matter in which there are illustrated and described
preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The invention will be described in more detail in the
following with reference to preferred embodiments and the
accompanying drawings in which:
[0033] FIG. 1 is a schematic sectional view of the basic
construction of a fluid flow machine constructed as a gas turbine
according to the prior art;
[0034] FIG. 2 is an enlarged section A from FIG. 1 showing a brush
seal of a fluid flow machine according to the prior art; and
[0035] FIG. 3 an enlarged section A' from FIG. 1 showing a brush
seal of a fluid flow machine according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0036] As is shown in FIGS. 1 and 3, a fluid flow machine 1 which
is constructed in this instance as a gas turbine has a stator 10
which is constructed in this instance as a gas turbine housing, a
rotor 20 which is constructed in this instance as a shaft which is
mounted so as to be rotatable relative to the stator 10, two
rotational bearings 30, 40 which form the rotatable bearing support
of the rotor 20 in the stator 10, and two brush seals 50' which
seal a gap S which is formed in a radial direction RR between the
stator 10 and rotor 20 so as to be prevent the passage of
fluid.
[0037] As can be seen particularly from FIG. 3, every brush seal
50' has a brush holder 51 and a plurality of sealing bristles 52
each of which has a first end fastened to the brush holder 51 and a
second end contacting a sealing surface D' so as to form a sealing
bristle-on-sealing surface contact zone, the sealing surface D'
being displaceable with respect to rotation, particularly rotatable
in this instance, relative to the second ends of the respective
sealing bristles 52.
[0038] As can be seen from FIG. 3, the sealing surface D' is formed
by an outer circumferential surface 61 of an intermediate sleeve 60
which is arranged between the stator 10 and rotor 20 and which is
mounted on the rotor 20 so as to be fixed with respect to rotation
relative to it and so as to divide the gap S radially. The brush
holder 51 is arranged at the stator 10 so as to be fixed with
respect to rotation relative to it.
[0039] The intermediate sleeve 60 divides the gap S radially into a
first gap portion adjoining the sealing surface D' and a second gap
portion adjoining an inner circumferential surface D'' of the
intermediate sleeve 60 remote of the sealing surface D'. A radial
extension of the second gap portion is greater than zero.
[0040] This means that an inner diameter of the intermediate sleeve
60 is greater than an outer diameter of the rotor (shaft) 20 so
that an annular gap LS is formed between the inner circumferential
surface of the intermediate sleeve 60 and an outer circumferential
surface 21 of the rotor 20.
[0041] In other words, an air gap (annular gap) LS is provided
between the intermediate sleeve 60 and the rotor 20 fastening the
latter, which air gap advantageously ensures a thermal insulation
between the intermediate sleeve 60 and the rotor 20. This makes it
more difficult for heat to be transferred from the sealing surface
D' to the rotor 20, which prevents a deformation of the rotor 20
fastening the intermediate sleeve 60 due to introduced heat.
[0042] Further, as can be seen from FIG. 3, the intermediate sleeve
60 has a flange 62 by means of which the intermediate sleeve 60 is
mounted at the flange mounting portion 22 of the rotor 20 so as to
be fixed with respect to rotation relative to it. The flange 62 is
arranged at an axial end of the intermediate sleeve 60 so that the
flange 62 has, at the axial end, an annular flange surface 62'
which contacts a recessed mounting surface (not designated
separately) of the flange mounting portion 22 in a fluid-tight
manner. Although not shown in FIG. 3, a flat seal can be provided
for achieving the fluid tightness and a thermal insulation between
the annular flange surface of the flange 62 and the recessed
mounting surface of the flange mounting portion 22.
[0043] As is shown in FIG. 3, the flange 62 is mounted at the
flange mounting portion 22 of the rotor 20 by detachable fastening
means which are realized in this instance in the form of a screw
connection.
[0044] In conclusion, the rotor 20 which is constructed in this
instance as a shaft is provided with an intermediate sleeve or
intermediate bushing 60 according to an embodiment of the
invention. The intermediate sleeve 60 is connected to the rotor 20
by means of an axial flange 62 and detachable fastening means.
There is an annular gap LS between the intermediate sleeve 60 and
the rotor 20. The sealing bristles or brush wires 52 of the brush
seal 50' contact the sealing surface D' formed by the outer
circumferential surface 61 of the intermediate sleeve 60.
[0045] Accordingly, in the event of an out-of-true state of the
intermediate sleeve 60, an uneven deformation of the intermediate
sleeve 60 may only aggravate the out-of-true state of the
intermediate sleeve 60 because the rotor 20 is only connected to
the intermediate sleeve 60 by the connection of its flange mounting
portion 22 to the flange 62 so that a direct heating of the rotor
20 caused by heat entering the area of the brush seal 50' is
prevented.
[0046] The solution according to the invention can be applied
wherever a fluid flow machine, e.g., a gas turbine, is to be sealed
with brush seals. The invention can be applied, e.g., in disk rotor
units, full rotor units and welded rotor units.
[0047] The solution according to the invention can be used to seal
a bearing periphery of a fluid flow machine and to seal between
individual stages of the fluid flow machine, e.g., compressor
stages or turbine stages.
[0048] Apart from the flange connection described above, fastening
of the intermediate sleeve to the part which fastens or holds it
can also be carried out by means of shrinking or welding or by
means of other fastening elements.
[0049] The invention is not limited by the embodiments described
above which are presented as examples only but can be modified in
various ways within the scope of protection defined by the appended
patent claims.
* * * * *