U.S. patent number 3,887,299 [Application Number 05/392,381] was granted by the patent office on 1975-06-03 for non-abradable turbine seal.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Air. Invention is credited to Daniel Profant.
United States Patent |
3,887,299 |
Profant |
June 3, 1975 |
Non-abradable turbine seal
Abstract
A non-abradable turbine seal for use between the blade member
and surrounding shroud of the turbine engine. The seal may take on
a variety of configurations, any one of which constructed to allow
deformation thereof by the blade member, either because of rotor
growth or shroud eccentricities. The seals are made of oxidation
resistant compressible or crushable materials in the form of thin
metallic foil, pads, ceramic hollow spheres or thin walled
tubing.
Inventors: |
Profant; Daniel (Glastonbury,
CT) |
Assignee: |
The United States of America as
represented by the Secretary of the Air (Washington,
DC)
|
Family
ID: |
23550357 |
Appl.
No.: |
05/392,381 |
Filed: |
August 28, 1973 |
Current U.S.
Class: |
415/173.4 |
Current CPC
Class: |
F01D
11/12 (20130101) |
Current International
Class: |
F01D
11/08 (20060101); F01D 11/12 (20060101); F01d
011/08 () |
Field of
Search: |
;415/113,172A,173,174,214 ;277/96,233 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Raduazo; Henry F.
Attorney, Agent or Firm: Erlich; Jacob N.
Claims
I claim:
1. In a turbine engine comprising a rotating blade member and a
surrounding fixed shroud wherein said improvement comprises a
non-abradable seal having an outer housing located within and fixed
to said shroud, said outer housing being made of an easily
deformable foil material and a thin deformable foil material of
sine-wave configuration being located within said outer housing
with the peaks and depressions of the sine-wave being directed
axially and facing the rotating blade member; thereby allowing for
the lateral displacement of said seal under the action of said
rotating blade member.
2. In a turbine engine as defined in claim 1 wherein said foil
material is between 5-10 mils thick.
3. In a turbine engine as defined in claim 2 wherein said foil
material is NiCrAlY.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to seals to be used with turbine
blades, and more particularly, to compressible or crushable seals
which permit the deformation thereof by either rotor shroud
eccentricities or rotor growth.
It is well known that the efficiency of the gas turbine engine is
dependent in part upon the dimensional tolerances that are
maintained during the production of the engine assembly. A
particularly difficult dimensional tolerance to maintain is
concerned with the peripheral seal between the free ends of the
rotor blades and the surrounding casing. The use of abradable
sealing materials as a lining for the casings is well known in the
art. Such materials have been used to avoid damage due to the
rubbing contact of the rotor blades with the compressor casing and
further, to effect the necessary seal between the moving parts.
The problems encountered by the use of abradable turbine outer
seals are numerous. For example, these seals have either oxidized
and/or eroded in the severe turbine environment or conversely, the
more dense materials that resist erosion are not sufficiently
abradable and cause excessive blade wear. In addition, the
relatively high processing temperature required to manufacture such
abradable materials creates problems of distortion and dimensional
inaccuracy in the seal structure. As a result of such high
processing temperature requirements, the abradable seal material is
difficult to repair or patch after assembly in an engine or in an
engine component.
SUMMARY OF THE INVENTION
The instant invention sets forth a plurality of seal structures
which are compressible or crushable and thereby overcome the
problems set forth hereinabove.
The seals set forth in this invention permit seal deformation by
either the turbine shroud eccentricities or the rotor growth but
yet avoid the erosion which has occurred in porous, metallic
abradable seal material utilized in the past. These seals are
capable of being inserted within the shroud or spacer which
surrounds the the blade member of a conventional turbine engine and
may take on a variety of configurations. For example, they may be
formed of foil and subsequently brazed or welded to the shroud in
such a manner to permit lateral movement thereof or in another
modification the foil may be crimped to minimize tensile stresses
during deformation in the engine. Additionally, cooling openings
may be inserted in the shroud. Furthermore, the seal may take on
the form of hollow spheres or folded sections manufactured of
compressible metal or ceramic felt. Also this filler material may
be in the form of thin walled tubes joined together and then brazed
within the shroud.
It is therefore an object of this invention to provide a
non-abradable, compressible or crushable seal which is capable of
use between relatively moveable parts.
It is another object of this invention to provide non-abradable
seal material which is strong and lightweight.
It is a further object of this invention to provide a seal material
which is economical to produce and which utilizes conventional,
currently available components that lend themselves to standard
mass producing manufacturing techniques.
For a better understanding of the present invention together with
other and further objects thereof reference is made to the
following description taken in connection with the accompanying
drawing and its scope will be pointed out in the appended
claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of one embodiment of the
non-abradable turbine seal of this invention, shown partially in
cross section;
FIG. 2 is a side elevational view of another embodiment of the
non-abradable turbine seal of this invention, shown partly in cross
section;
FIG. 3 is a side elevational view of a further embodiment of the
non-abradable turbine seal of this invention, shown partly in cross
section;
FIG. 4 is a side elevational view of still another embodiment of
the non-abradable turbine seal of this invention, shown partly in
cross section; and
FIG. 5 is a side elevational view of further embodiments of the
non-abradable turbine seal of this invention, shown partly in cross
section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is now made to FIGS. 1-5 of the drawing which set forth
the plurality of non-abradable turbine seals of the instant
invention. The turbine seals will be represented by numerals 10,
20, 30, 40 and 50 in FIGS. 1-5 of the drawing, respectively, and
like elements in each figure will be identified by like
numerals.
Generally, a shroud or spacer 12 cooperates with and surrounds a
blade member 14, one of which rotates with respect to the other in
a conventional turbine arrangement. For example, blade member 14
can be attached to a rotating compressor wheel (not shown) or
shroud 12 can be carried between and rotate with rotating
compressor wheels (not shown) opposite a stationary blade member
14. Located within shroud 12 and opposite blade member 14 is the
turbine seal 10, 20, 30, 40 or 50 of this invention.
Reference is now made to FIG. 1 of the drawing which sets forth a
rectangular-shaped non-abradable compressible seal 10 made up of a
foil material 16. This seal 10 forms a housing which is secured
within shroud 12. Foil 16 is of nominal 5-10 mil thickness and
manufactured of an oxidation resistant and easily deformable metal
such as NiCrAlY, FeCrAlY, Hastelloy X. Within foil housing 16 is a
foil strip 18 of similar material to foil 16 but of sine-wave
configuration. The foil housing 16 as well as the sine-wave foil 18
are welded or brazed together at appropriate places 19. The
configuration as shown in FIG. 1 permits the lateral movement of
turbine seal 10 under the action of blade 14.
Reference is now made to FIG. 2 of the drawing. The turbine seal 20
set forth therein has an upper foil member 22 made of any suitable
easily deformable material as set forth hereinabove fixedly secured
to shroud 12 with a plurality of curved foil sections 18 located
therebetween. A plurality of apertures 24 are located within shroud
12 and allow for the admittance of cooling air or other fluid
during the operation of the turbine. It should also be pointed out
that apertures 24 are capable of being used within any embodiment
shown in FIGS. 1-5.
FIG. 3 sets forth a crushable turbine seal 30 having an outer
structure 16 similar in nature to the outer structure 16 in FIG. 1.
In the embodiment shown in FIG. 3, however, the sine-wave foil
strip 18 is replaced by a plurality of crushable metal or ceramic
hollow spheres 32. This arrangement again allows for the
deformation of seal 30 under the action of blade 14.
FIG. 4 sets forth turbine seal 40 which contains therein a straight
piece of foil material 42 within an outer foil housing 16 and
further contains therein compressible metal or ceramic felt or
matte 44 of about 10-15% density.
FIG. 5 illustrates a turbine seal 50 which takes the form of a
plurality of thin walled tubular shaped elements 52. Elements 52
may be of a cylindrical shape 54, oval shape 56 or hollow elements
of any other desired configuration 58. Any suitable deformable
material as set forth hereinabove can be utilized in their
manufacture.
The non-abradable seals 10, 20, 30, 40 and 50 of this invention are
capable of being interchanged within shroud 12 depending upon the
type of blade 14 or shroud 12 construction. With the non-abradable
seals set forth hereinabove virtually all problems heretofore
encountered with abradable seals have been eliminated.
Although this invention has been described with reference to a
variety of embodiments which will be understood to those skilled in
the art, this invention is also capable of further embodiments
within the spirit and scope of the appended claims.
* * * * *