U.S. patent application number 11/138449 was filed with the patent office on 2006-11-30 for gas turbine moving blade having a platform, a method of forming the moving blade, a sealing plate, and a gas turbine having these elements.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Friedrich Soechting, Shunsuke Torii, Masanori Yuri.
Application Number | 20060269409 11/138449 |
Document ID | / |
Family ID | 37387825 |
Filed Date | 2006-11-30 |
United States Patent
Application |
20060269409 |
Kind Code |
A1 |
Torii; Shunsuke ; et
al. |
November 30, 2006 |
Gas turbine moving blade having a platform, a method of forming the
moving blade, a sealing plate, and a gas turbine having these
elements
Abstract
A platform of a gas turbine moving blade suppresses the effects
of thermal elongation and thus improves cooling performance. A
structure is constituted by a peripheral edge of a platform of a
gas turbine moving blade, a bottom of the platform, and a shank of
the moving blade. A cavity is blocked by disposing a sealing plate
so as to seal the recessed section, while a supply route is formed
for supplying air from cooling passages through an interior of the
shank to the cavity, each of the passages being for air-cooling the
interior of the gas turbine moving blade with air blown out from
the cavity to a surface of the platform. A method of appropriately
installing the sealing plate is also disclosed.
Inventors: |
Torii; Shunsuke;
(Takasago-shi, JP) ; Soechting; Friedrich; (Miami,
FL) ; Yuri; Masanori; (Takasago-shi, JP) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW
SUITE 700
WASHINGTON
DC
20036
US
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
37387825 |
Appl. No.: |
11/138449 |
Filed: |
May 27, 2005 |
Current U.S.
Class: |
416/97R |
Current CPC
Class: |
F05D 2260/2214 20130101;
F05D 2240/81 20130101; F05D 2240/55 20130101; F05D 2260/2212
20130101; F01D 5/187 20130101 |
Class at
Publication: |
416/097.00R |
International
Class: |
F01D 5/18 20060101
F01D005/18 |
Claims
1. A gas turbine moving blade having a platform, comprising: a
recessed section constituted by a peripheral edge of said platform,
a bottom thereof, and a shank of the moving blade, said recessed
section being formed with a cavity closed by disposing a sealing
plate between the peripheral edge of said platform and the shank;
said cavity being formed with a supply route for supplying air from
cooling passages through the interior of the shank to said cavity,
each of said cooling passages configured for air-cooling the
interior of the gas turbine moving blade; and said cavity being
provided with a plurality of cooling passage holes, each of said
cooling passage holes configured for allowing air to flow from said
cavity to a surface of said platform.
2. A gas turbine moving blade having a platform according to claim
1, wherein said sealing plate is fixed at least at one end to
either a groove provided at a lower end of the peripheral edge of
said platform or to a groove provided in the shank.
3. A gas turbine moving blade having a platform according to claim
I or 2, wherein each of said cooling passages is bored for the air
to flow from the surface of said platform radially in a direction
away from the blade.
4. A gas turbine moving blade having a platform according to claim
I or 2, wherein, at a longitudinal cross section of said cavity,
the width of said cross section is narrowed along the peripheral
edge of said platform.
5. A gas turbine moving blade having a platform according to claim
2, wherein said sealing plate is inserted into grooves and then
welded or brazed for fixing.
6. A gas turbine moving blade having a platform according to claim
1, wherein said sealing plate is inclined toward the peripheral
edge of said platform.
7. A gas turbine moving blade having a platform according to claim
1, wherein a dimpled plate is used as said sealing plate.
8. A gas turbine moving blade having a platform according to claim
7, wherein said sealing plate has a dimple that has a thin and long
shape.
9. A gas turbine moving blade having a platform according to claim
7, wherein said sealing plate has a plurality of dimples.
10. A gas turbine moving blade having a platform according to claim
1, wherein said sealing plate is a plate formed by connecting a
plurality of plates to one another in a lateral direction.
11. A gas turbine moving blade having a platform according to claim
1, wherein said sealing plate is a plate that has a curved
shape.
12. A sealing plate for a gas turbine moving blade cavity,
comprising a plurality of protruding pieces on peripheral sections
of said sealing plate.
13. A sealing plate for a gas turbine moving blade cavity according
to claim 12, including a through-hole in each of said plurality of
protruding pieces.
14. A sealing plate for a gas turbine moving blade cavity according
to claim 13, having a notch outside each of said plurality of holed
protruding pieces.
15. A method for forming a gas turbine moving blade having a
platform, comprising: forming a recessed section by using a
peripheral edge of said platform, a bottom thereof, and a shank of
the moving blade; inserting at least one end of a sealing plate
having protruding pieces into either a groove previously provided
in a lower end portion of a platform peripheral edge or in said
shank section of the moving blade; fixing each of said protruding
pieces to said groove; and fixing a peripheral edge of said sealing
plate.
16. The platform-forming method for a gas turbine moving blade
having a platform according to claim 15, wherein, a notch formed in
each of said protruding pieces is cut open and spread outward for
fixing.
17. A gas turbine using a gas turbine moving blade, having a
platform, comprising: a recessed section constituted by a
peripheral edge of said platform, a bottom thereof, and a shank of
the moving blade, said recessed section being formed with a cavity
closed by disposing a sealing plate between the peripheral edge of
said platform and the shank; said cavity being formed with a supply
route for supplying air from cooling passages through the interior
of the shank to said cavity, each of said cooling passages
configured for air-cooling the interior of the gas turbine moving
blade; and said cavity being provided with a plurality of cooling
passage holes, each of said cooling passage holes configured for
allowing air to flow from said cavity to a surface of said
platform.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a gas turbine moving blade
having a platform and is intended to suppress any effects of
thermal elongation on the platform and thus to improve cooling
performance thereof
[0003] 2. Description of the Prior Art
[0004] FIG. 9 is a perspective view of a typical platform 103 of a
gas turbine moving blade 101 used primarily as a first-stage moving
blade. Structurally, the moving blade has a platform integrated
with a profile and profile-equipped root forming a blade 102. Below
the platform, a blade root 151 of a Christmas-tree shape is formed
and, as shown in FIG. 10, engaged to a groove 162 formed into the
same shape as that of a rotor disc 161. Such plural moving blades
are fixed in a parallel fashion to the grooves provided in the
rotor disc, and there is a cavity 117 formed by a platform of the
same stage and a shank 104 of the moving blade. The cavity is
provided to supply sealing air from the rotor side and thus to
prevent high-temperature combustion gas from leaking from a gas
path thereof through clearances present between platforms. One
means of cooling the platform is described below. In an embodiment
according to conventional technology, as shown in U.S. Pat. No.
6,196,799 (Japanese Laid-Open Patent Publication No. JP11-236805),
a platform 103 of the gas turbine moving blade is shown in FIGS.
11(a) and 11(b). FIG. 11(a) is a plan of the platform 103, and FIG.
11(b) is a cross-sectional view of section A-A in FIG. 11(a).
Numeral 117 denotes an internal cavity of the platform 103, and the
cavity is formed at one side of the platform. Numeral 123 also
denotes cavities, which are formed on the other side of the
platform 103. Numerals 122a, 122b, 122c, and 122d each denote a row
of multiple cooling holes. These rows of cooling holes individually
communicate with the respective cavities and are each bored
obliquely on the periphery of the platform 103 on one side thereof.
These rows of cooling holes are provided to obtain an oblique flow
of air in an upward direction and diffuse the air as sealing air
for cooling the surface of the platform. In this embodiment, the
sealing air is used for cooling, and in each of the cavities 117,
123 on a lower face of the platform 103, an impingement plate 171
is installed to block the cavity 117, 123. The sealing air is
introduced as cooling air from a large number of impingement holes
172 within the impingement plate 171, into the cavity in order to
provide impingement cooling.
[0005] It produces a certain effect to cool the surface of the
platform in this way by introducing sealing air into the cavity at
the bottom of the platform and allowing the air to flow from the
cavity further to the surface of the platform via the cooling holes
provided on the surface.
[0006] Sealing air is intended to prevent the main stream of
high-temperature gas from leaking, and it usually does not control
temperature. In addition, it is not advisable for a large quantity
of sealing air to be used for other purposes. The air used to cool
the blade, however, is supplied to the blade independently of the
sealing air and, when necessary, after being cooled. Compared with
the sealing air, therefore, the cooling air has the advantages that
it can be used for cooling-temperature control purposes and that
its flow rate can be adjusted.
SUMMARY OF THE INVENTION
[0007] Briefly, the present invention was made in order to provide
a method and means suitable for cooling a moving blade having a
platform and not dependent on platform cooling with sealing air
only.
[0008] As described above, in the moving blades of a gas turbine,
cooling air is supplied to cool each of the blades and a platform
and thus to suppress increases in the temperatures of the
respective metals due to a high-temperature combustion gas. In the
moving blades of the gas turbine, a significant difference in mass
exists between the platform and a profile section of each blade,
and if a significant temperature difference occurs between both,
this will cause a great thermal stress. The occurrence of a great
thermal stress between the platform and the profile section of the
blade makes cracking prone to occur particularly at sections
exposed to the most thermally-severe conditions. These sections
include, for example, the blade and a hub located at the trailing
edge where the platform is planted. The present invention focuses
particularly on the thermal stress of the platform and on the
burned portions. Such damage is caused by a combination of creep
rupture based on many years of high-temperature, high-stress
operation, and fatigue-based destruction due to the stresses
repeatedly applied with each start/stop operation. To prevent the
damage, therefore, it is necessary to reduce to the lowest possible
level the temperatures of and (thermal) stresses on sections prone
to have concentrated stresses (i.e., the platform base sections at
leading and trailing edges of the blade).
[0009] Accordingly, the present invention was made with the aim of
providing a gas turbine moving blade whose reliability can be
improved by introducing modifications in structural sections
particularly susceptible to thermal stresses (i.e., a cooling
structure of sections distanced from internal cooling passages of
the blade), suppressing the occurrence of cracking and thermal
damage due to thermal stresses, and extending the service life of
the platform.
[0010] In order to solve the foregoing problems, the present
invention may be embodied as follows:
[0011] In one embodiment of the present invention, a gas turbine
moving blade having a platform has a recessed section constituted
by a peripheral edge of a platform, a bottom, and a shank of a
moving blade, the recessed section being formed with a cavity
closed by disposing a sealing plate between the peripheral edge of
the platform and the shank; the cavity being formed with a supply
route for supplying air from cooling passages, through the interior
of the shank to the cavity, each of the cooling passages configured
for air-cooling the interior of the gas turbine moving blade; and
the cavity being provided with a plurality of cooling passage holes
each for allowing air to flow from said cavity to a surface of said
platform. The above structure is effective in that it suppresses
cracking and thermal damage due to thermal stresses, extends the
service life of the platform, and improves reliability thereof.
[0012] The sealing plate may be fixed at least at one end to either
a groove provided at a lower end of the peripheral edge of the
platform or to a groove provided in the shank. A cavity effective
for cooling is thus formed.
[0013] Each of the cooling passages may be bored for the air to
flow from the surface of the platform radially in a direction away
from the blade. Platform cooling is thus made more effective.
[0014] At a longitudinal cross section of the cavity, the width of
the cross section may be narrowed along the peripheral edge of the
platform. Thus, cooling is conducted with minimum cooling air.
[0015] The sealing plate may be inserted into the grooves and then
welded or brazed for fixing. This yields a positive effect in a
process of making installation of the sealing plate in a cavity
easy and reliable.
[0016] The sealing plate may be inclined toward the peripheral edge
of the platform. Thus, cooling is conducted with minimum cooling
air.
[0017] A dimpled plate may be used as the sealing plate. Thus,
there arises an effect that gives strength to the sealing plate and
minimizes runout thereof due to thermal elongation.
[0018] The sealing plate may have a dimple of a thin and long
shape. This arrangement has the effect that structurally, strength
of the sealing plate, runout thereof due to thermal elongation, and
the like can be matched to a shape of the sealing plate.
[0019] The sealing plate has a plurality of dimples independent of
one another. This produces the effect that structurally, strength
of the sealing plate, runout thereof due to thermal elongation, and
the like can be matched to a shape of the sealing plate.
[0020] The sealing plate is a plate formed by connecting a
plurality of plates to one another in a lateral direction. This
produces the effect that structurally, strength of the sealing
plate, runout thereof due to thermal elongation, and the like can
be matched to a shape of the sealing plate.
[0021] The sealing plate is a plate of a curved shape. This
produces the effect that structurally, strength of the sealing
plate, runout thereof due to thermal elongation, and the like can
be matched to a shape of the sealing plate.
[0022] In another embodiment of the invention, a sealing plate for
a gas turbine moving blade cavity has a plurality of protruding
pieces on peripheral sections of the sealing plate. The sealing
plate may include a through-hole in each of the plural protruding
pieces. The sealing plate may also include a notch outside each of
the plurality of holed protruding pieces. This arrangement makes
installation of the sealing plate in a cavity easy and
reliable.
[0023] In another embodiment of the invention, a method for forming
a gas turbine moving blade having a platform includes: forming a
recessed section by using a peripheral edge of the platform, a
bottom thereof, and a shank of the moving blade; inserting at least
one end of a sealing plate having protruding pieces into a groove
previously provided in either a lower end portion of a platform
peripheral edge or in the shank section of the moving blade; fixing
each of the protruding pieces to the groove and fixing a peripheral
edge of the sealing plate. This platform-forming method has
improved workability. A notch formed in each of the protruding
pieces may be cut open and spread outward for fixing. Based on this
arrangement, the sealing plate can be installed easily and
reliably.
[0024] In another embodiment of the invention, a gas turbine using
a gas turbine moving blade having a platform includes: a recessed
section constituted by a peripheral edge of the platform, a bottom
thereof, and a shank of the moving blade, the recessed section
being formed with a cavity closed by disposing a sealing plate
between the peripheral edge of the platform and the shank; the
cavity being formed with a supply route for supplying air from
cooling passages through the interior of the shank to the cavity,
each for air-cooling the interior of the gas turbine moving blade;
and the cavity being provided with a plurality of cooling passage
holes, each for allowing air to flow from the cavity to a surface
of the platform.
[0025] In the above gas turbine structure, the entire gas turbine
can effectively use cooling air.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1(a) shows a longitudinal section of a gas turbine
moving blade according to Embodiment 1 of the present invention,
and FIG. 1(b) is a cross-sectional view of section A-A in FIG.
1(a);
[0027] FIG. 2 shows cross section B-B of the platform in FIG.
1;
[0028] FIG. 3 shows an enlarged cross section of a platform bottom
cavity enclosed in dotted line C of FIG. 2;
[0029] FIG. 4 is a semi-cutaway of the major sections viewed in
perspective from the bottom of the platform in Embodiment 1 of the
present invention;
[0030] FIG. 5 is a partly enlarged cross-sectional view of section
D-D in FIG. 4;
[0031] FIG. 6 is a partly enlarged cross-sectional view showing a
sealing plate of another embodiment;
[0032] FIGS. 7(a) to 7(g) are plans of various sealing plates used
in the present invention;
[0033] FIGS. 8(a) to 8(c) show, in a partly enlarged form, a manner
of installing a sealing plate in a cavity according to the present
invention, wherein FIG. 8(a) is a plan of the sealing plate, FIG.
8(b) a cross-sectional view of an installation section, and FIG.
8(c) a partly enlarged view showing a step of forming a major
section in cross section C-C of FIG. 8(b);
[0034] FIG. 9 shows a perspective view of a general gas turbine
moving blade;
[0035] FIG. 10 shows a cavity at a blade-installed section in a
parallel arrangement of gas turbine moving blades; and
[0036] FIGS. 11(a) and 11(b) show the cooling structure of a gas
turbine moving blade platform according to an embodiment of
conventional technology.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Embodiments of a gas turbine moving blade platform according
to the present invention are described below on the basis of the
accompanying drawings.
Embodiment 1
[0038] FIG. 1(a) shows a longitudinal section of, for example, a
first-stage gas turbine moving blade according to Embodiment 1 of
the present invention, and FIG. 1(b) is a cross-sectional view of
section A-A in FIG. 1(a).
[0039] A gas turbine moving blade 1 includes a blade 2 that forms a
profile, a platform 3 bonded with a rooted section of the blade 2,
and a shank 4 located under the platform 3. The interior of the
blade 2 is constructed so that cooling air is first supplied from a
blade root (Christmas-tree-like shape not shown here) that leads to
a rotor (not shown) disposed under the blade, to cooling air
passages 5. The cooling air is then supplied to a leading-edge
passage 6 and serpentine fluid passages 7,8, each disposed inside
the blade, so as to cool the blade interior. In a cooling passage
9, part of the cooling air is blown out from a trailing edge 10 to
cool the edge 10, and the remainder of the cooling air is blown out
from a blade top 11 into a gas path. In addition, the leading edge
6 lets cooling air flow from outflow holes located at a leading
edge of the blade, and the remainder of the cooling air is
discharged from the blade top 11 into the gas path. Furthermore, as
shown in FIG. 1(b), at a blade head 12, blade convex portion 13,
and blade concave portion 14 of the blade, a surface thereof has a
plurality of outflow holes 15, whereby cooling is also
effected.
[0040] FIG. 2 shows one form of the platform 3 when it is viewed
from cross section B-B in FIG. 1(a). Under the platform 3, as shown
in detail in FIG. 3 as an enlarged cross-sectional view of section
C in FIG. 2, a peripheral edge 16 has, in the lower section of FIG.
3, a lower end 16a, and a cavity 17 is formed by the lower end 16a
and the shank 4. A sealing plate 18 for closing the cavity is also
installed. In order to retain this plate securely, the
aforementioned shank and the aforementioned peripheral edge are
provided with a groove 19a and a groove 19b, respectively, and the
plate 18 is placed between the two grooves, while a peripheral edge
of the plate is fixed by means of welding, brazing, or the
like.
[0041] A cooling passage 20 to the cavity 17 communicates from any
of the cooling passages 5 extending to the blade interior and cools
a section 21 particularly prone to the accumulation of heat in the
cavity and thus liable to suffer thermal damage. Cooling air from
the cooling passage 20 passes through a plurality of cooling
passages 22a, 22b, 22c, and 22d, and then flows out from the
platform to cool the surface thereof. In this case, one preferred
embodiment may be formed with air flowing out radially air from
each of the cooling passages. Cooling becomes more efficient when
the cooling passages are distributed across the perimeter instead
of being concentrated on the side.
[0042] Another cavity 23 in the platform is not equipped with a
sealing plate, and it is adapted to use sealing air. In addition, a
peripheral edge cooling passage 24 of the platform communicates
with a passage 25. Furthermore, although other cooling passages 26
and 27 are also provided, these passages are configured differently
from that of the cavities in the platform of the present invention.
That is to say, neither of the two cavities 17,23 is blocked by a
sealing plate.
[0043] FIG. 4 is a semi-cutaway of the major sections viewed in
perspective from the bottom of the platform 3 in Embodiment 1 of
the present invention. In FIG. 4, a structure with the sealing
plate 18 installed to block the cavity 17 is shown, and the sealing
plate 18 has four protruding pieces 18a, 18b, 18c, and 18d. The
number of protruding pieces, however, is not limited to four.
[0044] FIG. 5 is a cross-sectional view of section D-D in FIG. 4,
showing an installation state of the sealing plate 18 in the cavity
17. The sealing plate 18 is inserted between the groove 19a of the
shank and the groove 19b at the peripheral edge of the platform via
the protruding pieces 18a and 18b, with the periphery of the plate
fixed through welding or brazing. If, before the protruding pieces
18a and 18b are fixed to the grooves 19a and 19b by being inserted
thereinto, the grooves are arranged to take an angle of .alpha.
(where .alpha. is an appropriate angle from 90 to 135 degrees) with
respect to the shank, workability with a tool used for welding,
brazing, or the like, is enhanced since the tool can be easily used
at a short distance from the shank and since the plate can be
easily installed.
[0045] Since the platform surface of the gas turbine moving blade
is a section through which combustion gas flows, it is exposed to a
high temperature. The roots of the blade and the platform are also
exposed to a high temperature, and their temperatures also
increase, but the surface of the platform becomes most
significantly hot. Compared with the platform surface and the roots
of the blade and platform, the bottom of the platform and the shank
are placed in a very low-temperature state. Accordingly, a thermal
stress may arise on the platform, causing tension and hence,
cracking. Therefore, it becomes necessary to cool these elements
uniformly so as not to heat them to a temperature exceeding their
thermal characteristics. In view of this, in the present invention,
a cavity is formed at the bottom of the platform to improve cooling
of this section.
Embodiment 2
[0046] FIG. 6 shows a form of installation of a sealing plate
according to another embodiment, with a curved sealing plate 18
installed between a platform peripheral-edge lower end 16a and a
shank groove 19a demonstrated. This installation form is suitable
when a large cavity is to be formed, and when the lower end of the
platform cannot be easily grooved.
Embodiment 3
[0047] FIGS. 7(a) to 7(g) show plane and lateral-face shapes of
various types of sealing plates. FIG. 7(a) shows a flat type
composed of one flat plate, and FIG. 7(b) shows an arch type of
plate having a thin and long dimple 18-1 extending along almost the
entire length of the plate. FIG. 7(c) shows a sealing plate
provided with a container-type dimple 18-2 forming a flat recess in
the center. Furthermore, FIG. 7(d) shows a recessed type of sealing
plate having two independent, thin and long dimples 18-3 and 18-4
approximately in the center. Besides, FIG. 7(e) shows a recessed
combination type of sealing plate having a thin and long dimple
18-5 or 18-6 on both the surface and reverse side of the plate.
FIG. 7(f) shows a sealing plate having a plurality of independent,
protruding spherical dimples on the surface or reverse side of the
plate. FIG. 7(g) shows, as a modified type of plate in FIG. 7(a), a
connected type of sealing plate constituted by several plates 18-8
and 18-9 bonded with one another by means of welding, brazing, or
the like. Each of these types prevents the deformation of the
sealing plate due to thermal elongation thereof, and can have
sufficient strength, even if the plate is thin.
Embodiment 4
[0048] FIGS. 8(a) to 8(c) show an installation process of a sealing
plate. FIG. 8(a) is a plan of a flat plate 18 having protruding
pieces 18a, 18b, 18c, and 18d, in four peripheral sections.
Referring to 18b as a typical one of the four protruding pieces, a
hole is provided in an approximate center of the protruding piece,
and a notch 18b-1, at a front end thereof. Next, as shown in FIG.
8(b), which is a partly enlarged view of the above-mentioned plate
18 with one end inserted into a groove 19b at the lower end of the
platform, one end of peripheral edge 16 of platform 3 is to be
fitted into the protruding piece 18b, and subsequently, partial
sealing is provided from the interlocking of peripheral edge 16 and
protruding piece 18b. Next, as shown in FIG. 8(c), which is a
partly enlarged view of cross section C-C in FIG. 8(b), the ends of
the notch in the protruding piece 18b-1 are spread to fully insert
the plate into the groove. After this, the periphery of the plate
is welded or brazed for fixing.
[0049] In a gas turbine moving blade according to the present
invention, a recessed section constituted by a peripheral edge of a
platform, the bottom thereof, and a shank of the moving blade, is
formed at a section prone to damage due to thermal stress on the
platform, while a cavity blocked by a sealing plate is disposed
between the peripheral edge of the platform and the shank. With
cooling air for cooling the interior of the moving blade supplied
to the cavity through an interior of the shank and blown out from
the cavity to the platform surface that becomes very hot, it is
possible to prevent damage and cracks without causing temperature
changes with respect to other sections. When using sealing air as
in the conventional technology described above, achieving the
intended purpose of sealing air prevents a large quantity of air
from being used for cooling. Compared with the conventional
technology, therefore, the cooling air supplied from internal
cooling passages of the gas turbine moving blade has sufficient
cooling performance, thus being greatly effective for cooling.
[0050] Furthermore, in the present invention, when a cavity is
formed, a sealing plate can be reliably fixed in place by welding
or brazing after providing a groove at appropriate parts both the
platform peripheral edge and the shank adjacent the cavity.
[0051] The present invention has another advantage: a more reliable
method of fixing the above-mentioned sealing plate, i.e.,
interlocking of a protruding piece of the sealing plate so that
workability for the plate is thereby enhanced.
[0052] The platform of a gas turbine moving blade according to the
present invention is significantly meaningful for industrial
applications in that the platform improves cooling performance and
hence, service life performance, and in that it enhances the
workability in its forming method.
[0053] While the present invention has been described with respect
to the embodiments as illustrated, the invention is not limited
thereto but may naturally include various structural modifications
within the scope of the claims below.
* * * * *