U.S. patent application number 14/965244 was filed with the patent office on 2016-06-23 for blading member for a fluid flow machine.
The applicant listed for this patent is ALSTOM Technology Ltd. Invention is credited to Eribert BENZ, Herbert BRANDL.
Application Number | 20160177749 14/965244 |
Document ID | / |
Family ID | 52146264 |
Filed Date | 2016-06-23 |
United States Patent
Application |
20160177749 |
Kind Code |
A1 |
BRANDL; Herbert ; et
al. |
June 23, 2016 |
BLADING MEMBER FOR A FLUID FLOW MACHINE
Abstract
A blading member for a fluid flow machine, for example, for use
in gas turbine engines. The blading member includes a platform
member and an airfoil member. The platform member and airfoil
member are designed to allow for easy assembly/disassembly and
replacement of members independent of other members.
Inventors: |
BRANDL; Herbert;
(Waldshut-Tiengen, DE) ; BENZ; Eribert;
(Birmenstorf, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ALSTOM Technology Ltd |
Baden |
|
CH |
|
|
Family ID: |
52146264 |
Appl. No.: |
14/965244 |
Filed: |
December 10, 2015 |
Current U.S.
Class: |
416/219R |
Current CPC
Class: |
F01D 9/042 20130101;
F01D 5/3023 20130101; F05D 2240/80 20130101; F01D 5/3007 20130101;
F01D 9/044 20130101; F01D 5/225 20130101; F01D 5/02 20130101; F05D
2260/30 20130101; F05D 2220/32 20130101; F05D 2240/30 20130101 |
International
Class: |
F01D 5/30 20060101
F01D005/30 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2014 |
EP |
14199453.3 |
Jun 12, 2015 |
EP |
15171782.4 |
Claims
1. A blading member for a fluid flow machine, the blading member
comprising a platform member and at least one airfoil member, the
platform member comprising a platform member receiver section, said
platform member receiver section comprising a first face and a
second face (8), and a platform member receiver opening being
disposed in the receiver section, the receiver opening extending
from the first face, the airfoil member extending from an airfoil
base to an airfoil tip and comprising an airfoil member foot
section and an airfoil member aerodynamic section, wherein the
airfoil member foot section extends from the airfoil base to the
airfoil member aerodynamic section and the airfoil member
aerodynamic section extends from the airfoil member foot section to
the airfoil tip, the airfoil member foot section comprising an
airfoil member male mating section received within the platform
member receiver opening and the airfoil member aerodynamic section
projecting from the first face of the platform member receiver
section, wherein at least one support shoulder is disposed on the
airfoil foot section and a counterpart support shoulder is disposed
on the platform member, wherein the support shoulder and the
counterpart support shoulder abut each other, characterized in that
at least one support shoulder and a corresponding counterpart
support shoulder are beveled, wherein the bevel angles (a) of said
support shoulder and said corresponding counterpart support
shoulder are at least essentially identical at least at
corresponding mating points to within .+-.5.degree. or less.
2. The blading member according to claim 1, wherein the platform
member receiver opening is a platform member receiver through
opening extending from the first face to the second face.
3. The blading member according to claim 1, wherein the counterpart
support shoulder is provided within the platform member receiver
opening.
4. The blading member according to claim 1, wherein the bevel angle
(a) is constant along the extent of the shoulder.
5. The blading member according to claim 1, wherein the support
shoulder is at least provided on a side of the airfoil member foot
section disposed on a suction side of the airfoil member
aerodynamic section and on a side of the airfoil member foot
section disposed on a pressure side of the airfoil member
aerodynamic section.
6. The blading member according to claim 1, wherein the support
shoulder extends on the periphery of a cross section of the airfoil
member foot section from a side disposed on a pressure side of the
airfoil aerodynamic section to a side disposed on a suction side of
the airfoil member aerodynamic section.
7. The blading member according to claim 1, wherein the support
shoulder extends around the entire periphery of a cross section of
the airfoil member foot section.
8. The blading member according to claim 1, wherein the counterpart
support shoulder is at least provided on a side of the platform
member receiver opening which is disposed on a suction side of the
airfoil member aerodynamic section and on a side of the platform
member receiver opening which is disposed on a pressure side of the
airfoil member aerodynamic section.
9. The blading member according to claim 1, wherein the counterpart
support shoulder extends on the periphery of a cross section of the
platform member receiver opening from a side which is disposed on a
pressure side of the airfoil aerodynamic section to a side which is
disposed on a suction side of the airfoil member aerodynamic
section.
10. The blading member according to claim 1, wherein the
counterpart support shoulder extends around the entire periphery of
a cross section of the platform member receiver opening.
11. The blading member according to claim 1, wherein the platform
member comprises a multitude of platform receiver openings and the
blading member further comprises a corresponding multitude of
airfoil members, wherein at least the airfoil member male mating
section of the airfoil member foot section of each airfoil member
is received in a platform receiver opening.
12. The blading member according to claim 1, further comprising an
airfoil member head section is provided at the airfoil tip of an
airfoil member, the blading member further comprising a second
platform member with at least one platform receiver opening being
provided in the second platform member, wherein at least a male
mating section of the airfoil head section is received in the
platform receiver opening of the second platform member.
13. The blading member according to claim 12, wherein a beveled
support shoulder is provided on the airfoil head section and a
corresponding mating counterpart support shoulder is provided on
the second platform member and in particular within a second
platform member receiver opening in which the airfoil member head
section is received.
14. An airfoil member for a blading member according to claim 1,
the airfoil member comprising an airfoil aerodynamic section and an
airfoil member foot section, wherein a support shoulder is provided
on the airfoil member foot section, characterized in that the
support shoulder is beveled.
15. A platform member for a blading member according to claim 1,
the platform member comprising a receiver section, said receiver
section comprising a first face and a second face, and a receiver
opening being disposed in the receiver section and extending from
the first face, wherein a counterpart support shoulder is provided
on the platform member, and wherein in particular the platform
receiver opening is a platform receiver through opening, wherein
further in particular the counterpart support shoulder is provided
within the receiver opening, characterized in that the counterpart
support shoulder is beveled.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to EP Application No.
14199453.3 filed Dec. 19, 2014 and EP Application No. 15171782.4
filed Jun. 12, 2015, both of which are hereby incorporated in their
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to the field of blading
members for fluid flow machines as described in the preamble of
claim 1. It further relates to an airfoil member and a platform
member of blading members as mentioned above. Such blading members
may for instance be applied in gas turbine engines.
BACKGROUND
[0003] It is known in the art to manufacture airfoils and platforms
of blading members of fluid flow machines separately and to
assemble a blading member from at least one airfoil member and at
least one platform member. This offers various benefits, e.g.
different materials may be used for the airfoil and the platform,
complexity of the individual pieces is reduced, thus allowing for
more complex cooling schemes, and in providing individual
geometries more suitable for casting or machining. However,
airfoils and platforms need to be joined properly and reliably.
[0004] It may generally be stated that it may be found beneficial
if the joint between the two members may easily be disassembled,
preferably without damaging any of the members, and particularly
not damaging the platform member. This facilitates for instance
replacement of worn airfoils, while the platform member may be
further used.
[0005] EP 1 176 284 proposes joining airfoils and platforms by
brazing.
[0006] U.S. Pat. No. 5,797,725 discloses blading members wherein
each of the airfoil and the platform comprise a corresponding flute
which are filled by a common retainer. In a preferred embodiment
the retainer is manufactured inside the flutes by casting, and in
particular by a process referred to a bi-casting.
[0007] U.S. Pat. No. 7,686,571 and U.S. Pat. No. 7,704,044 propose
coupling airfoils and platforms applying a mechanical interlock
element, wherein said mechanical interlock element is slidably
received inside flutes provided in the platform and along the
pressure or suction side of the airfoil.
[0008] According to the teaching of US 2012/0009071 airfoil and
platform members are joined and locked to each other in inserting a
flexible wire into corresponding recesses of the members to be
locked.
[0009] US 2009/0196761 describes joining airfoil and platform
members by a so-called injection molding process.
[0010] Moreover, European patent application 14 199 453.3, to which
priority is claimed and the entire content of which is furthermore
incorporated herein by reference, discloses blading member and a
method for assembling and joining the blading member, wherein
mechanical interlock members are provided in order to virtually
generate an undercut by which the airfoil member and the platform
member are interlocked.
[0011] Independent from the actual process or device applied for
interlocking said members, there is a need to properly position the
members before interlocking them. In US 2009/0196761 for instance a
built blading member is disclosed wherein the airfoil member
features a shoulder which abuts a corresponding counterpart
shoulder formed on the platform member. The counterpart shoulder
may be provided within a receiver opening of the platform member,
or may likewise be provided as a section of a face of the platform
member, adjacent the receiver opening.
SUMMARY
[0012] It is an object of the present disclosure to provide a
blading member for a fluid flow machine which comprises, and is
assembled from, at least one airfoil member and a platform member.
It is a further object of the present disclosure to address the
issues related to the assembly of a blading member of the kind
initially mentioned. In one aspect, it is an object of the present
disclosure to provide a blading member which overcomes drawbacks of
the art cited above. It is a further object of the present
disclosure to provide an airfoil member which overcomes drawbacks
of the art cited above. It is still a further object of the present
disclosure to provide a platform member which overcomes drawbacks
of the art cited above. In another aspect it is an object of the
present disclosure to provide a blading member in which at least
one airfoil member and platform member may be easily assembled and
be reliably and precisely positioned to each other before joining
them by any appropriate means or method, including, but not limited
to, the methods disclosed in the art cited above. Further, in this
respect, airfoil members and platform members suitable to build the
blading member are an additional object of the present disclosure.
In still another aspect, a method for assembling a blading member
as referred to above.
[0013] This is achieved in providing a blading member according to
claim 1. It is further achieved in providing an airfoil member or a
platform member according to any of the further independent
claims.
[0014] Further effects and advantages of the disclosed subject
matter, whether explicitly mentioned or not, will become apparent
in view of the disclosure provided below.
[0015] In the context of this disclosure a blading member may be a
part of a running blade row as well as a part of a stationary guide
vane row, and a blading member may comprise one or more airfoils. A
platform or shroud may be arranged at the foot as well as at the
tip of an airfoil or of multiple airfoils.
[0016] A blading member for a fluid flow machine according to the
present disclosure comprises a platform member and at least one
airfoil member. The platform member comprises a platform member
receiver section, said platform member receiver section comprising
a first face and a second face, and a platform member receiver
opening being disposed in the receiver section, the receiver
opening extending from the first face. The airfoil member extends
from an airfoil base to an airfoil tip and comprises an airfoil
member foot section and an airfoil member aerodynamic section,
wherein the airfoil member foot section extends from the airfoil
base to the airfoil member aerodynamic section and the airfoil
member aerodynamic section extends from the airfoil member foot
section to the airfoil tip. The airfoil member foot section
comprises an airfoil member male mating section received within the
platform member receiver opening. The airfoil member aerodynamic
section projects from the first face of the platform member
receiver section. It is understood that this does not require the
airfoil member aerodynamic section to project from a surface which
is flush with the first face of the platform member receiver
section, but it is well within the scope of this statement, for
instance, that the airfoil member foot section might protrude from
the platform member receiver section first face, and the airfoil
member aerodynamic section starts from there. It is further
understood that this means that the first face of the platform
member receiving section points towards the airfoil tip. At least
one support shoulder is disposed on the airfoil foot section, and a
counterpart support shoulder is disposed on the platform member,
wherein the support shoulder and the counterpart support shoulder
abut each other. At least one support shoulder and a corresponding
counterpart support shoulder are beveled, wherein the bevel angles
of said support shoulder and said corresponding counterpart support
shoulder are identical at least at corresponding mating points. It
will be appreciated that in practice the bevel angles will be
slightly different due to manufacturing tolerances. Slight
deviations which will be considered acceptable without compromising
the function of shoulders by the person skilled in the art are also
well within the scope of this disclosure and are covered by the
above statement. The allowable difference may depend on the actual
bevel angle, but an acceptable deviation between the bevel angle of
a support shoulder and the mating counterpart support shoulder at
corresponding mating contact points may be as large as
.+-.2.degree. or even .+-.5.degree..
[0017] Each of the support shoulder and counterpart support
shoulder may comprise a flat surface, but may also comprise a
convexly rounded surface. In certain embodiments, one of the
support shoulder and counterpart support shoulder may comprise or
be provided as a convexly rounded surface, while the other one of
the support shoulder and counterpart support shoulder may comprise
or be provided as a flat surface.
[0018] Due to the beveling of the corresponding shoulders, the
airfoil member comprises a male tapered section, while the platform
member receiver opening comprises a mating female tapered section.
By virtue of these interacting tapering sections the airfoil member
becomes properly centered in the platform member receiver opening
when the members are assembled, and a self-centering assembly
interface is provided.
[0019] The bevel angle, as measured against a line perpendicular to
an airfoil member longitudinal axis, wherein longitudinal is to be
understood as extending along the airfoil spanwidth, may generally
be anywhere between 0.degree. and 90.degree., but may more
specifically be larger than or equal to 30.degree. and smaller than
or equal to 60.degree.. Larger than or equal to 40.degree. and
smaller than or equal to 50.degree. may be found a particularly
appropriate range. Generally, the larger the angle is, that is, the
more acute the resulting tapering sections are, the better the
airfoil member is centered, while the smaller the angle is, that is
the more obtuse the resulting tapering section are, the more
precise the airfoil is positioned in its longitudinal
direction.
[0020] The blading member may comprise a multitude of airfoil
members. All airfoil members comprised in one blading member may be
connected to a platform in a similar manner and in particular in
applying the teaching of the present disclosure. Further, a second
platform member or a shroud member may be arranged at and connected
to the airfoil tip. The connection between the second platform
member and the airfoil or the airfoils may be affected in the
manner described in the present document, or in any other suitable
manner.
[0021] In particular, the platform member receiver opening may be a
platform member receiver through opening extending from the first
face to the second face. This might provide improved access for
interlocking the members, compared to a blind receiver opening.
Further in particular, the counterpart support shoulder may be
provided within the platform member receiver opening.
[0022] In another aspect, an airfoil member for a blading member
according to the present disclosure is disclosed, the airfoil
member comprising an airfoil aerodynamic section and an airfoil
member foot section, wherein a support shoulder is provided on the
airfoil member foot section, and wherein the support shoulder is
beveled. In still another aspect, a platform member for a blading
member according to the present disclosure is disclosed, the
platform member comprising a receiver section, said receiver
section comprising a first face and a second face, and a receiver
opening being disposed in the receiver section and extending from
the first face, wherein a beveled counterpart support shoulder is
provided on the platform member, wherein in particular the beveled
counterpart support shoulder is provided within the receiver
opening, and wherein in particular the platform receiver opening is
a platform receiver through opening.
[0023] In some embodiments, the support shoulder of the airfoil
member points towards the airfoil member base, while the
counterpart support shoulder of the platform member points towards
the airfoil tip. In other words, at the support shoulder the
airfoil member tapers along a direction from the airfoil tip to the
airfoil base, while the platform member comprises a section of the
platform member receiver opening at the counterpart support
shoulder where the platform member receiver opening tapers in a
direction from the first face to the second face. Accordingly, an
airfoil member and a platform member exhibiting said features are
disclosed. These embodiments are suited for assembling the blading
member in inserting the airfoil member into the platform receiver
opening with the airfoil base first, or, from the first face of the
platform member receiver opening.
[0024] In other embodiments the support shoulder of the airfoil
member points towards the airfoil member tip, while the counterpart
support shoulder of the platform member points towards the airfoil
base. In other words, at the support shoulder the airfoil member
tapers along a direction from the airfoil base to the airfoil tip,
while the platform member comprises a section of the platform
member receiver opening at the counterpart support shoulder where
the platform member receiver opening tapers in a direction from the
second face to the first face. Accordingly, an airfoil member and a
platform member exhibiting said features are disclosed. These
embodiments are suited for assembling the blading member in
inserting the airfoil member into the platform receiver opening
with the airfoil tip first, or, from the second face of the
platform member receiver opening. It is moreover understood that
these embodiments may be well suited for rotating blading members,
as the support shoulder and the counterpart support shoulder would
then bear centrifugal forces acting on the airfoil member.
[0025] The bevel angle of the shoulders may be constant along the
extent of a shoulder, which facilitates manufacturing, as for
instance only one tool applied at one specific angle may be
required to manufacture the beveled shoulders.
[0026] A shoulder may at least be provided on a side of the airfoil
member foot section disposed on a suction side of the airfoil
member aerodynamic section and on a side of the airfoil member foot
section disposed on a pressure side of the airfoil member
aerodynamic section. These may be two distinct support shoulders.
In further embodiments a support shoulder extends on the periphery
of a cross section of the airfoil member foot section from a side
disposed on a pressure side of the airfoil aerodynamic section to a
side disposed on a suction side of the airfoil member aerodynamic
section such that the support shoulders being present on said two
sides of the airfoil member may be part of one support shoulder. In
still more specific embodiments, a support shoulder extends around
the entire periphery of a cross section of the airfoil member foot
section.
[0027] Likewise, a counterpart support shoulder may at least be
provided on a side of the platform member receiver opening which is
disposed on a suction side of the airfoil member aerodynamic
section and on a side of the platform member receiver opening which
is disposed on a pressure side of the airfoil member aerodynamic
section. As to the platform member as such this means that a
counterpart support shoulder may at least be provided on a side of
the platform member receiver opening which is intended, or
configured and arranged, respectively, to be arranged on a suction
side of the airfoil member aerodynamic section and on a side of the
platform member receiver opening which is intended, or configured
and arranged, respectively, to be arranged on a pressure side of
the airfoil member aerodynamic section. These may be two distinct
counterpart support shoulders. In other embodiments, a counterpart
support shoulder extends on the periphery of a cross section of the
platform member receiver opening from a side which is arranged on a
pressure side of the airfoil aerodynamic section to a side which is
arranged on a suction side of the airfoil member aerodynamic
section. As to the platform member as such this means that a
counterpart support shoulder may extend on the periphery of a cross
section of the platform member receiver opening from a side of the
platform member receiver opening which is intended, or configured
and arranged, respectively, to be arranged on a suction side of a
airfoil member aerodynamic section to a side of a platform member
receiver opening which is intended, or configured and arranged,
respectively, to be arranged on a pressure side of the airfoil
member aerodynamic section. In an even more specific embodiment a
counterpart support shoulder extends around the entire periphery of
a cross section of the platform member receiver opening.
[0028] The skilled person will readily understand how the different
configurations of support shoulders and counterpart support
shoulders lined out above may be best combined.
[0029] As mentioned above, the blading member as disclosed herein
is well suited for providing blading members comprising multiple
airfoils. To that extent, the platform member may comprise a
multitude of platform receiver openings. The blading member may
further comprise a corresponding multitude of airfoil members,
wherein at least the airfoil member male mating section of the
airfoil member foot section of each airfoil member is received in a
platform receiver opening.
[0030] In still another aspect of the blading member according to
the present disclosure, a platform or shroud may be provided on
both longitudinal ends of the airfoil member, that is, at the
airfoil base and at the airfoil tip. Accordingly, an airfoil member
head section may be provided at the airfoil tip of an airfoil
member. The blading member, in respective embodiments, further
comprises a second platform member or shroud with at least one
platform receiver opening being provided therein, wherein at least
a male mating section of the airfoil head section is received in a
platform receiver opening of the second platform or shroud
member.
[0031] The airfoil member and the platform member may be joined or
interlocked by any appropriate method and/or locking device,
including, but not limited to, the methods and/or locking devices
mentioned above. For instance, the assembly may be interlocked or
joined by bi-cast, injection molding, locking pins, any other
mechanical interlock, and so forth. To provide a further example,
they may be locked to each other in that mechanical interlock
members are provided in order to virtually generate an undercut by
which the airfoil member and the platform member are locked to each
other, as is described in European patent application 14 199 453.3,
which is furthermore incorporated herein by reference in its
entirety, and more specifically the respectively pertinent
disclosure of which is incorporated herein by reference.
Accordingly, disclosed is a blading member comprising interlock
means, and in particular interlock means as disclosed in any of the
above cited references. Further disclosed is a blading member
wherein the airfoil member and the platform member are joined or
interlocked by any method as disclosed in any of the above cited
references.
[0032] Disclosed to this extent are furthermore a blading member,
an airfoil member, and a platform member, wherein at least one
flute or other depression is provided on at least one of the
airfoil member and the platform member, wherein further such
depression is suitable to receive a locking means for interlocking
the airfoil member and the platform member. In particular, said
depression may be provided inside the receiver opening and/or on
the mating section of the airfoil member foot. In more particular
embodiments, depressions are provided on the airfoil member as well
as in the platform member receiver opening, and arranged such that,
when the airfoil member and the platform member are assembled, they
are arranged adjacent each other, in essence forming a combined
cavity. Such combined cavity may for instance be filled by a method
such as above-referenced bi-cast or injection molding, in order to
form an interlock feature inside the combined cavity.
[0033] A method for assembling the airfoil member and the platform
member to form a blading member according to the present disclosure
comprises inserting the airfoil member foot section into the
platform member receiver opening from the first face, and mating a
support shoulder provided on the foot section of the airfoil member
and a counterpart support shoulder provided on the platform, and in
particular within the platform member receiver opening, thereby
centering the airfoil member foot section, or the airfoil member
male mating section, respectively, within the platform member
opening.
[0034] A further method for assembling the airfoil member and the
platform member to form a blading member according to the present
disclosure comprises inserting the aerodynamic section of the
airfoil member into a platform member receiver through opening from
the second face, forwarding the aerodynamic section through the
receiver through opening, and further advancing the airfoil member
in said direction through the receiver through opening until a
support shoulder provided on the foot section of the airfoil member
and a counterpart support shoulder provided on the platform member,
and in particular within the platform member receiver opening,
mate, thereby centering the airfoil member foot section, or the
airfoil member male mating section, respectively, within the
platform member opening.
[0035] It is understood that subsequently the assembly may be
locked by any of the methods or in applying any of the locking
devices referred to above.
[0036] It is understood that the features and embodiments disclosed
above may be readily combined with each other. It will further be
appreciated that further embodiments are conceivable within the
scope of the present disclosure and the claimed subject matter
which are obvious and apparent to the skilled person.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The subject matter of the present disclosure is now to be
explained in more detail by means of selected exemplary embodiments
shown in the accompanying drawings. The figures show
[0038] FIG. 1 a general overview of an airfoil member and a
platform member according to the present disclosure;
[0039] FIG. 2 details of a first embodiment of the airfoil member
and the platform member;
[0040] FIG. 3 details of a second embodiment of the airfoil member
and the platform member;
[0041] FIG. 4 details of an exemplary embodiment of the interface
between the airfoil member and the platform member of a blading
member according to the present disclosure;
[0042] FIG. 5 details of a further exemplary embodiment of the
interface between the airfoil member and the platform member of a
blading member according to the present disclosure;
[0043] FIG. 6 details of still a further exemplary embodiment of
the interface between the airfoil member and the platform member of
a blading member according to the present disclosure;
[0044] FIG. 7 an exemplary embodiment of a blading member with a
platform member being provided on both longitudinal ends of an
airfoil member.
[0045] It is understood that the drawings are highly schematic, and
details not required for instruction purposes may have been omitted
for the ease of understanding and depiction. It is further
understood that the drawings show only selected, illustrative
embodiments, and embodiments not shown may still be well within the
scope of the herein disclosed and/or claimed subject matter.
DETAILED DESCRIPTION
[0046] FIG. 1 depicts a first exemplary embodiment of the blading
member according to the present disclosure. Shown are an airfoil
member 1 and a platform member 2. The airfoil member 1 comprises an
airfoil member aerodynamic section 3 and an airfoil member foot
section 4 extending from an airfoil base 16 to the airfoil
aerodynamic section 3. The platform member 2 comprises a receiver
opening 5 provided in a receiver section 6 and extending from a
first face 7 of the receiver section to a second face 8 of the
receiver section. The platform member receiver opening 5 is shaped
and dimensioned such as to receive airfoil member foot section 4,
or a mating section thereof. Furthermore, the airfoil member
aerodynamic section 3 comprises a concavely curved pressure side 10
and a convexly curved suction side 11. The airfoil further
comprises a leading edge and a trailing edge (without reference
numerals) as is apparent to the skilled person. The leading edge
and the trailing edge separate the pressure side and the suction
side from each other. It may be found beneficial if the cross
sections of the airfoil foot section and the airfoil aerodynamic
section are by and large similar to each other. Thus, also the
airfoil foot section may comprise a convexly shaped surface and a
concavely shaped surface, as well as the platform receiver opening
may comprise a convexly shaped area and a concavely shaped area.
The platform member may in other embodiments also comprise multiple
receiver sections and receiver openings and may thus be adapted to
receive a multitude of airfoil members, such that a blading member
may comprise a multitude of airfoils. A support shoulder 12 is
provided on the airfoil member, while a counterpart support
shoulder 13 is provided on the platform member. Support shoulder 12
and counterpart support shoulder 13, in this specific embodiment,
run as ledges around the foot section 4 and the receiver opening 5
as a closed loop from a suction side area to a pressure side area.
However, other embodiments in which for instance a multitude of
support shoulders and/or counterpart support shoulders,
respectively, are arranged on areas adjacent the pressure and the
suction side of the airfoil aerodynamic section, or, in other
words, a shoulder may not be a continuous ledge, but an interrupted
ledge, thus resulting in said multitude of support shoulders or
counterpart support shoulders, respectively.
[0047] FIG. 2 depicts in more detail the assembly of an airfoil
member 1 and a platform member 2. The drawing depicts two possible
embodiments of an interlock member which might be applied for
locking the assembly, and which is lined out in more detail in
European patent application 14 199 453.3. As is seen, the airfoil
member 1 is inserted into the receiver opening 5 from top to
bottom, or, more precisely said, from the first face 7 towards the
second face 8 of the platform receiver section 6. Receiver opening
5, in this embodiment, is provided as a receiver through opening,
extending from the first face 7 to the second face 8. The
aerodynamic section of the airfoil member 1 is in this embodiment
partially received within the platform receiver opening 5 and
projects from the first face 7. A support shoulder 12 is provided
on the airfoil member and abuts a counterpart support shoulder 13
formed within the receiver through opening 5. A male mating section
14 of the airfoil member foot section 4 is received within the
platform member receiver opening 5 and may in particular fit snugly
within the receiver opening. The airfoil member foot section 4 in
part projects from the platform member receiver section second face
8. An airfoil base 16 thus is located outside the receiver opening.
Support shoulder 12 which is provided on airfoil member 1 matingly
abuts counterpart support shoulder 13 which provided on the
platform, and in this embodiment within the receiver opening.
Support shoulder 12 and counterpart support shoulder 13 are beveled
at at least approximately and essentially identical bevel angles a.
While the surface of support shoulder 12 points to the airfoil
base, the surface of counterpart support shoulder 13 points to the
airfoil tip, or, to the first face 7. In other words, the beveled
shoulders 12, 13 provide for a tapered section of the airfoil
member and for a tapered section of the receiver opening, both
tapering in a direction from the airfoil tip to the airfoil base,
or from the receiver section 6 first face 7 to the receiver section
6 second face 8, respectively. Due to the thereby provided mating
tapers, the airfoil is centered in the receiver opening, and at the
same time a well-defined position in the airfoil longitudinal
direction, that is, a direction extending between the airfoil base
and the airfoil tip, is provided for. On the left-hand part of FIG.
2, a first exemplary configuration of an interlock member, a
retainer member and an interlock receiver recess is shown. An
interlock receiver recess 9 is provided in the airfoil foot section
4. An interlock member 15 is provided in the interlock receiver
recess and comprises a section protruding therefrom. An interlock
counterpart seating surface 17 is provided on the platform member
receiver section second face 8 and bears the seating surface of the
interlock member 15. A retainer member 18 is provided which is on
the one hand interlocked with the platform and on the other hand
mates with the interlock member 15. Retainer member 18 is
weld-connected to interlock member 15 by a weld connection 19. To
assemble the blading member, firstly the airfoil foot 4 is inserted
through the receiver through opening 5 and forwarded from the first
face 7 towards the second face 8 until support shoulder 12 abuts
and mates with counterpart support shoulder 13, thereby, due to the
interaction of the tapering sections provided by the shoulders 12
and 13, centering the airfoil member within the receiver opening.
Then interlock member 15 is inserted into interlock receiver recess
9. Retainer member 18 is introduced into an undercut provided on
platform member 2 and brought into abutting contact with interlock
member 15. Thereafter, weld connection 19 is produced. The location
of weld connection 19 is easily accessible if the blading member is
not mounted to a rotor or a stator, and may thus be easily produced
and also disjoined for inspection, servicing and reconditioning
purposes. As is seen, a part of the platform receiver section is
form locked between support shoulder 12 and interlock member 15,
and thus the platform member and the airfoil member are locked to
each other. With reference to the right-hand side of FIG. 2, a
second configuration of an interlock recess 9, an interlock member
20 and a spring type retainer member 21 is shown. Spring-type
retainer member 21 applies a force directed towards the ground of
the interlock receiver recess 9 on the interlock member 20. Due to
the wedge shape of interlock member 20 in the shown cross-section,
a force directed from the platform member receiver section first
face 7 towards the second face 8 becomes effective on the airfoil
member 1, and the bearing surface of the support shoulder 12 is
firmly pressed onto the corresponding counter support shoulder 13
provided in the platform receiver through opening.
[0048] With reference to FIG. 3, a reverse configuration is shown.
The airfoil member 1 is inserted into the platform receiver through
opening 5 in a direction from the second face 8 towards the first
face 7. The airfoil member foot section extends only through a part
of the platform member receiver through opening 5. Airfoil base 16
is thus located inside the receiver through opening 5. Support
shoulder 12 which is provided on airfoil member 1 matingly abuts
counterpart support shoulder 13 provided on platform 2, and in this
embodiment within receiver opening 5. Support shoulder 12 and
counterpart support shoulder 13 are beveled at an at least
approximately and essentially identical bevel angle a. While the
surface of support shoulder 12 points to the airfoil tip, the
surface of counterpart support shoulder 13 points to the airfoil
base, or, to the second face 8. In other words, the beveled
shoulders 12, 13 provide for a tapered section of the airfoil
member and for a tapered section of the receiver opening, both
tapering in a direction from the airfoil base to the airfoil tip,
or, from the receiver section 6 second face 8 to the receiver
section 6 first face 7, respectively. Due to the thereby provided
mating tapers, the airfoil is centered in the receiver opening, and
at the same time a well-defined position in the airfoil
longitudinal direction, that is, a direction extending between the
airfoil base and the airfoil tip, is provided for. As is seen, the
bevel angle in this embodiment is smaller than in the embodiment of
FIG. 2. This difference in the angle is not tied to the different
configuration, but the angle may be chosen dependent on various
parameters.
[0049] For instance, the smaller bevel angle provides for a more
precise positioning in the longitudinal direction, while larger
bevel angles support centering or the airfoil member in the
receiver opening. However, it will be appreciated that the smaller
bevel angle may support bearing centrifugal forces if a rotating
blade member is provided by an arrangement as shown in FIG. 3.
Interlock receiver recess 22 is provided on a platform member
receiver through opening 5 inner wall. Interlock members 15, 20 are
provided in the interlock receiver recess or recesses provided on
opposite sides of the platform member receiver through opening.
FIGS. 4 through 6 depict in more detail the arrangement of support
shoulders and counterpart support shoulders of various exemplary
embodiments of blading members according to the present
disclosure.
[0050] FIG. 4 depicts a longitudinal cut through one embodiment.
Airfoil member 1 is joined with platform member 2 to form a blading
member. In this longitudinal cut, internal cooling channels 101 are
schematically indicated inside airfoil member 1 in a manner known
per se in order to indicate the possibility of internal cooling
structures being present. However, it should be noted that these
cooling structures are not relevant to the subject matter of the
present disclosure, and are only schematically hinted at in FIG. 4
as well as in the subsequent figures, while omitting any details.
It is understood that within the frame of this disclosure for
instance airfoil members exhibiting significantly more complex
cooling structures as well as airfoil members without any cooling
structures are possible. Airfoil member 1 and platform member 2
comprise beveled support shoulder 12 and beveled counterpart
support shoulder 13, which mate in order to properly place airfoil
member 1 relative to platform member 2. Counterpart support
shoulder 13 is arranged within the receiver opening and at a
distance d from the first face 7, or hot gas side, of the platform
receiver section 6. Distance d might for instance be in a range
from 0 to 20 mm, or in other embodiments from 0 to 10 mm, wherein
the boundary values are included in the said range. Along distance
d a lateral gap with gap width c is provided. Gap width c may for
instance be larger than or equal to 0.01 mm and smaller than or
equal to 2.0 mm. Also, between the mating shoulders and the second
face 8 of platform receiver section 6, or airfoil base 16,
respectively, a lateral gap is provided. Said lateral gaps
facilitate insertion of airfoil member 1 into the receiver opening
provided in platform member receiver section 6. Airfoil base 16 is
shown flush with the second surface 8 of the platform receiver
section. This feature, however, is not mandatory. Flutes 24 and 25,
of which the cross section is visible in the present depiction, are
provided on an inner wall of platform receiver section 6 and on
airfoil member foot section 4. The flutes 24 and 25 are arranged on
the platform member and the airfoil member, respectively, such
that, when the airfoil member and the platform member are
assembled, they are located adjacent each other, and at least
exhibit an overlap with each other, such as to form a combined
cavity. A retainer or interlock member may be inserted or
manufactured filling the combined cavity and thus interlocking
airfoil member 1 and platform member 2. The interlock member may
for instance be manufactured in place inside the common cavity in
applying, to name some, a method like bi-casting or injection
molding which have been referred to above. Instead of flutes, any
other pair or pairs of overlapping depressions may be provided to
receive an interlock member.
[0051] With reference to FIG. 5, a further embodiment is shown. The
mating shoulders 12, 13 are arranged immediately adjacent the first
face 7 of platform receiver section 6. The first face of platform
receiver section 6 as well as the surface of airfoil member 1 is
shaped such as to provide a smooth transition surface between
airfoil member 1 and platform member 2. Said radius may in certain
embodiments provide, for instance, aerodynamic benefits for a hot
gas flow flowing over the first face 7 and around the airfoil
aerodynamic section when the blading member operates in a turbo
engine. In the manner described above, flutes 24 and 25 are
provided, forming a combined cavity suited to receive any
appropriate kind of interlock or retainer feature for interlocking
airfoil member 1 and platform member 2.
[0052] While in the above mentioned figures the flutes, or
interlocking feature, respectively, has been shown to be disposed
towards the cold gas side, or, towards the airfoil base,
respectively, as seen from the mating beveled shoulders, FIG. 6
depicts an embodiment wherein the interlocking feature is disposed
towards the hot gas side, or the airfoil tip, respectively.
Disposing the interlocking feature towards the cold gas side from
the mating shoulders may exhibit the advantage of better isolating
the interlocking feature from hot gases, in particular hot
combustion gases. However, also an arrangement as provided in the
embodiment of FIG. 6 may be found beneficial. Besides, FIG. 6
depicts various exemplary geometries for the transition between the
first face 7 of the platform receiver section 6 and the outer
surface of the airfoil member 1. These transition geometries are
not beforehand relevant to the subject matter of the present
disclosure, and may be chosen by the skilled person dependent on,
for example, aerodynamic properties or other criteria.
[0053] FIG. 7 depicts a disassembled embodiment of the blading
member according to the present disclosure wherein a second
platform or shroud 200 is arranged at the tip of the airfoil member
1. On one longitudinal end of the airfoil member 1 an airfoil
member foot section 4 is provided, which is in accordance with the
subject matter of the present disclosure, that is, amongst other
features, a beveled support shoulder is provided. The platform
receiver opening is provided in platform member 2 and is suited to
receive airfoil member foot section 4, or a part thereof, while
also a beveled counterpart support shoulder is provided on platform
member 2. At the tip of the airfoil, head section 400 is provided,
while the second platform member 200 comprises a platform receiver
opening suited to receive the airfoil head section 400. At the
interface between the airfoil head section 400 and second platform
200, beveled shoulders, and other features described above at the
interface between foot section 4 and platform member 2, may or may
not be provided. Generally, second platform member 200 may also be
attached to the airfoil member in any other suitable manner.
[0054] In the exemplary embodiments lined out above, the airfoil
foot section and the platform receiver through opening have been
shown with the cross section essentially resembling the cross
section of an airfoil aerodynamic section. While this is a suitable
embodiment, and may in particular be useful to avoid overly abrupt
or stepwise changes of the airfoil member cross-section, this is
not a mandatory feature.
[0055] Embodiments comprising multiple airfoils will in the light
of the explanations above be apparent to the skilled person without
exemplary embodiments being explicitly shown.
[0056] While the subject matter of the disclosure has been
explained by means of exemplary embodiments, it is understood that
these are in no way intended to limit the scope of the claimed
invention. It will be appreciated that the claims cover embodiments
not explicitly shown or disclosed herein, and embodiments deviating
from those disclosed in the exemplary modes of carrying out the
teaching of the present disclosure will still be covered by the
claims.
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