Technical Field
[0001] The present invention relates to a turbine rotor blade applied to a gas turbine,
a steam turbine, and the like.
Background Art
[0002] As a known turbine rotor blade applied to a gas turbine, a steam turbine, and the
like, there is a turbine rotor blade that is provided with a blade root that is slotted
into a blade groove formed on the circumferential portion of a turbine disc to hold
the whole blade, a blade portion that is exposed to high-temperature gas, a platform
that supports this blade portion, a shank that connects the blade root and the platform,
and a shroud that extends in the circumferential direction from the end of the blade
portion (see, for example, Patent Citation 1).
Patent Citation 1: Japanese Unexamined Patent Application, Publication No.
2006-283681
Disclosure of Invention
[0003] In recent years, however, it has been required to reduce the leakage loss (leakage
of gas) at the end of the blade portion to improve the turbine efficiency, and to
make a blade frame of the blade portion smaller by reducing the vibration of the end
of the blade portion. Therefore, the plan-view shape of a shroud has become complex,
and with a method in which the blade roots of the turbine rotor blades are individually
slotted into the blade grooves on the turbine disc, as in the art, there has been
a problem in that it is difficult to slot the blade root of the final (last) turbine
rotor blade into the blade groove on the turbine disc since the shroud of the final
(last) turbine rotor blade interferes with the shrouds of the adjacent turbine rotor
blades positioned at both sides when the blade root of the final (last) turbine rotor
blade is slotted into the blade groove on the turbine disc.
There has been a further problem in that, if the length of the turbine rotor blade
(blade height) is as short (low) as, for example, 200 mm or less (more specifically,
if L (blade height) / D (chord length) is 1/3 or more), the blade root of the final
(last) turbine rotor blade cannot be slotted into the blade groove on the turbine
disc.
[0004] The present invention has been conceived in light of the circumstances described
above, and an object thereof is to provide a turbine rotor blade with which the blade
root of the final (last) turbine rotor blade can be slotted into the blade groove
on the turbine disc easily and rapidly even if the plan-view shape of the shroud of
the turbine rotor blade is complex.
[0005] In order to solve the problems described above, the present invention employs the
following solutions.
A turbine rotor blade according to one aspect of the present invention is a turbine
rotor blade provided with a blade root that is slotted into a blade groove formed
on a circumferential portion of a turbine disc to hold the whole blade, a blade portion
that is exposed to high-temperature gas, a platform that supports this blade portion,
a shank that connects the blade root and the platform, and a shroud that extends along
the circumferential direction from an end of the blade portion; the turbine rotor
blade has a cut-out portion that is cut out to a predetermined depth, either at the
leading edge or the trailing edge of the blade root, along the lengthwise direction
thereof, from the end of the blade root to an intermediate part of the shank.
[0006] According to the turbine rotor blade of one aspect of the present invention, the
turbine rotor blade can be set between a normal blade and a normal blade that have
been slotted into the blade grooves on the turbine disc to a predetermined depth (for
example, 5 mm) merely by moving the end surface that is formed by the cut-out portion
and that extends in the lengthwise direction in a plane that includes the end surfaces
forming the circumferential portion of the turbine disc (in other words, moving radially
inward from radially outward), when the blade root is slotted into the blade groove
formed on the circumferential portion of the turbine disc to be assembled.
[0007] In other words, even if the plan-view shape of the shrouds of the turbine rotor blade
and the normal blades are complex (regardless of the plan-view shapes of the shrouds),
by using the turbine rotor blade according to the above-mentioned aspect at least
as the final (last) blade to be slotted into the turbine disc, the blade root of the
turbine rotor blade and the blade roots of the normal blades can be slotted (are capable
of being slotted) into the blade grooves on the turbine disc easily and rapidly.
The turbine rotor according to one aspect of the present invention is provided with
the turbine rotor blade with which, when the blade root is slotted into the blade
groove formed on the circumferential portion of the turbine disc to be assembled,
the end surface that is formed by the cut-out portion and that extends in the lengthwise
direction can be moved in the plane that includes the end surfaces forming the circumferential
portion of the turbine disc (in other words, moved radially inward from radially outward);
therefore, simplification of the procedure for assembling the turbine rotor blade
and the normal blades on the turbine disc can be achieved, a reduction in the time
required for assembly can be achieved, and a reduction in production costs can be
achieved.
[0008] A method for constructing the turbine rotor according to the above-mentioned aspect
is a method for constructing a turbine rotor by slotting at least one turbine rotor
blade provided with a blade root that is slotted into a blade groove formed on a circumferential
portion of a turbine disc to hold the whole blade, a blade portion that is exposed
to high-temperature gas, a platform that supports this blade portion, a shank that
connects the blade root and the platform, a shroud that extends along the circumferential
direction from the end of the blade portion, and a cut-out portion that is cut out
to a predetermined depth, either at the leading edge or the trailing edge of the blade
root, along the lengthwise direction thereof from the end of the blade root to an
intermediate part of the shank; and a plurality of normal blades provided with a blade
root that is slotted into a blade groove formed on the circumferential portion of
the turbine disc to hold the whole blade, a blade portion that is exposed to high-temperature
gas, a platform that supports this blade portion, a shank that connects the blade
root and the platform, and a shroud that extends along the circumferential direction
from the end of the blade portion, into the turbine disc to complete the turbine rotor;
the method for constructing the turbine rotor includes a step of positioning the turbine
rotor blade between the normal blades by moving the turbine rotor blade radially inward
from radially outward, between the normal blades whose blade roots have been slotted
into the blade grooves on the turbine disc to a predetermined depth, and thereafter,
slotting the blade roots of the turbine rotor blade and the normal blades into the
blade grooves on the turbine disc by moving the turbine rotor blade and the normal
blades in the axis line direction of the turbine rotor.
[0009] With the method for constructing the turbine rotor according to the above-mentioned
aspect, the turbine rotor blade can be set between the normal blade and the normal
blade that have been slotted into the blade grooves on the turbine disc to a predetermined
depth (for example, 5 mm) merely by moving the end surface that is formed by the cut-out
portion and that extends in the lengthwise direction in the plane that includes the
end surfaces forming the circumferential portion of the turbine disc (in other words,
moving radially inward from radially outward), when the blade root is slotted into
the blade groove formed on the circumferential portion of the turbine disc to be assembled.
In other words, even if the plan-view shapes of the shrouds of the turbine rotor blade
and the normal blades are complex (regardless of the plan-view shapes of the shrouds),
by using the turbine rotor blade according to the one aspect of the present invention
at least as the final (last) blade to be slotted into the turbine disc, the blade
root of the turbine rotor blade and the blade roots of the normal blades can be slotted
(are capable of being slotted) into the blade grooves on the turbine disc easily and
rapidly.
Accordingly, simplification of the procedure for assembling the turbine rotor blade
and the normal blades on the turbine disc can be achieved, a reduction in the time
required for assembly can be achieved, and a reduction in production costs can be
achieved.
[0010] The turbine rotor blade according to the present invention affords an advantage in
that it is possible to easily and rapidly slot the blade root of the final (last)
turbine rotor blade into the blade groove on the turbine disc, even if the plan-view
shape of the shroud of the turbine rotor blade is complex.
Brief Description of Drawings
[0011]
[FIG. 1A] FIG. 1A is a side view showing a turbine rotor blade according to an embodiment
of the present invention.
[FIG. 1B] FIG. 1B is a plan view showing a turbine rotor blade according to an embodiment
of the present invention.
[FIG. 2] FIG. 2 is a perspective view of the turbine rotor blade shown in FIGS. 1A
and 1B, viewed from the front side.
[FIG. 3A] FIG. 3A is a side view showing a normal blade without a cut-out portion
shown in FIGS. 1A, 1B, and 2.
[FIG. 3B] FIG. 3B is a plan view showing a normal blade without a cut-out portion
shown in FIGS. 1A, 1B, and 2.
[FIG. 4] FIG. 4 is a perspective view of the normal blade shown in FIGS. 3A and 3B
viewed from the front side.
[FIG. 5] FIG. 5 is a perspective view for explaining an assembly procedure onto the
turbine disc.
[FIG. 6] FIG. 6 is a perspective view for explaining an assembly procedure onto the
turbine disc.
Explanation of Reference:
[0012]
- 1
- turbine rotor blade
- 2
- turbine disc
- 2a
- blade groove
- 3
- blade root
- 4
- blade portion
- 5
- platform
- 6
- shank
- 7
- shroud
- 8
- cut-out portion
- 11
- normal blade
- 13
- blade root
- 20
- turbine rotor
Best Mode for Carrying Out the Invention
[0013] An embodiment of a turbine rotor blade according to the present invention will be
described below with reference to FIGS. 1A, 1B, and 2.
FIG. 1A is a side view showing the turbine rotor blade according to this embodiment,
and FIG. 1B is a plan view showing the turbine rotor blade according to this embodiment.
FIG. 2 is a perspective view of the turbine rotor blade according to this embodiment
viewed from the front side.
[0014] The turbine rotor blade 1 according to this embodiment is applied to a gas turbine
provided with, for example, a compression unit (not shown) that compresses combustion
air, a combustion unit (not shown) that combusts fuel by injecting the fuel into the
high-pressure air sent from this compression unit, generating high-temperature combustion
gas, and a turbine unit (not shown) that is located downstream of this combustion
unit and is driven by the combustion gas discharged from the combustion unit.
[0015] As shown in FIGS. 1A, 1B, and 2, the turbine rotor blade 1 is provided with a Christmas
tree-shaped blade root (bottom) 3 that is slotted into a blade groove 2a (see FIGS.
5 and 6) formed on the circumferential portion of a turbine disc 2 (see FIGS. 5 and
6) to hold (support) the whole body of the turbine rotor blade 1, a blade portion
4 that is exposed to high-temperature gas, a platform 5 that supports this blade portion
4, a shank 6 that connects the blade root 3 and the platform 5, and a shroud 7 that
extends along the circumferential direction from the end (tip) of the blade portion
4 and that prevents resonance of the turbine rotor blade 1 and reduces the leakage
loss (leakage of gas) at the end of the blade portion 4.
[0016] As shown in FIGS. 1A and 2, the turbine rotor blade 1 according to this embodiment
has, either at the leading edge or the trailing edge of the blade root 3, a cut-out
portion 8 that is cut out uniformly (to a predetermined depth (for example, 5 mm))
along the lengthwise direction (vertical direction in FIGS. 1A and 2) of the turbine
rotor blade 1 from the end (lower end) of the blade root 3 to an intermediate part
of the shank 6. An end surface 8a that is formed by this cut-out portion 8 and extends
in the lengthwise direction (vertical direction in FIGS. 1A and 2) is formed so as
to become substantially parallel to end surfaces 2b formed on the circumferential
portion of the turbine disc 2 when the turbine rotor blade 1 is assembled with the
turbine disc 2; and the end surface 8a extends to the intermediate part of the shank
6.
[0017] In other words, the cut-out portion 8 of the turbine rotor blade 1 is formed so that,
in a state where the blade root 13 of a turbine blade 11 without the cut-out portion
8 (hereinafter referred to as "normal blade"), such as those shown in FIGS. 3A, 3B,
and 4, is slotted into the blade groove 2a on the turbine disc 2 to a predetermined
depth (for example, 5 mm), as shown in FIG. 5, the turbine rotor blade 1 can be set
between a normal blade 11 and a normal blade 11 by moving the end surface 8a that
is formed by the cut-out portion 8 and that extends in the lengthwise direction in
a plane that includes the end surfaces 2b forming the circumferential portion of the
turbine disc 2.
Then, as shown in FIG. 6, after the turbine rotor blade 1 is set between the normal
blade 11 and the normal blade 11, the turbine blade 1 and the normal blades 11 are
moved, as a whole, along the axial direction of the turbine disc 2, thereby slotting
all blade roots 3 and 13 of the turbine blade 1 and the normal blades 11 into the
blade grooves 2a formed on the circumferential portion of the turbine disc 2.
In FIGS. 3A, 3B, and 4, reference signs 4, 5, 6, and 7 are a blade portion, a platform,
a shank, and a shroud, respectively, and because descriptions thereof have been described
using FIGS. 1A, 1B, and 2, the descriptions thereof will be omitted here.
The reference sign 20 in FIGS. 5 and 6 indicates a turbine rotor that is provided
with at least one turbine rotor blade 1, a plurality of normal blades 11, and the
turbine disc 2.
[0018] The thus-configured turbine rotor blade 1 can be set between the normal blade 11
and the normal blade 11 that have been slotted into the blade grooves 2a on the turbine
disc 2 to a predetermined depth (for example, 5 mm) merely by moving the end surface
8a that is formed by the cut-out portion 8 and that extends in the lengthwise direction
in the plane that includes the end surfaces 2b forming the circumferential portion
of the turbine disc 2 (in other words, moving radially inward from radially outward),
when the blade root 3 is slotted into the blade groove 2a formed on the circumferential
portion of the turbine disc 2 to be assembled.
In other words, even if the plan-view shapes of the shrouds 7 of the turbine rotor
blade 1 and the normal blades 11 are complex (regardless of the plan-view shapes),
by using the turbine rotor blade 1 according to this embodiment at least as the final
(last) blade to be slotted into the turbine disc 2, the blade root 3 of the turbine
rotor blade 1 and the blade roots 13 of the normal blades 11 can be slotted (are capable
of being slotted) into the blade grooves 2a on the turbine disc 2 easily and rapidly.
[0019] According to the turbine rotor 20 of this embodiment, the turbine rotor 20 is provided
with the turbine rotor blade 1 with which, when the blade roots 3 and 13 are slotted
into the blade grooves 2a formed on the circumferential portion of the turbine disc
2 to be assembled, the end surface 8a that is formed by the cut-out portion 8 of the
turbine rotor blade 1 and extends in the lengthwise direction can be moved in the
plane that includes the end surfaces 2b forming the circumferential portion of the
turbine disc 2 (in other words, moved radially inward from radially outward); therefore,
simplification of the procedure for assembling the turbine rotor blade 1 and the normal
blades 11 on the turbine disc 2 can be achieved, a reduction in the time required
for assembly can be achieved, and a reduction in production costs can be achieved.
[0020] The present invention is not only applicable to a gas turbine, but may also be applied
to a steam turbine or a fluid rotary machine having other similar configurations.
The present invention is not limited to the embodiments described above; various modifications
and alterations are permissible as required, so long as they do not depart from the
technical idea of the present invention.
1. A turbine rotor blade provided with a blade root that is slotted into a blade groove
formed on a circumferential portion of a turbine disc to hold the whole blade, a blade
portion that is exposed to high-temperature gas, a platform that supports this blade
portion, a shank that connects the blade root and the platform, and a shroud that
extends along the circumferential direction from an end of the blade portion, the
turbine rotor blade comprising:
a cut-out portion that is cut out to a predetermined depth, either at the leading-edge
or the trailing-edge of the blade root, along the lengthwise direction thereof, from
the end of the blade root to an intermediate part of the shank.
2. A turbine rotor comprising:
at least one turbine rotor blade according to Claim 1;
a plurality of normal blades provided with a blade root that is slotted into a blade
groove formed on the circumferential portion of the turbine disc to hold the whole
blade, a blade portion that is exposed to high-temperature gas, a platform that supports
this blade portion, a shank that connects the blade root and the platform, and a shroud
that extends along the circumferential direction from the end of the blade portion;
and
the turbine disc.
3. A method for constructing a turbine rotor by slotting:
at least one turbine rotor blade provided with a blade root that is slotted into a
blade groove formed on a circumferential portion of a turbine disc to hold the whole
blade, a blade portion that is exposed to high-temperature gas, a platform that supports
this blade portion, a shank that connects the blade root and the platform, a shroud
that extends along the circumferential direction from the end of the blade portion,
and a cut-out portion that is cut out to a predetermined depth, either at the leading
edge or the trailing edge of the blade root, along the lengthwise direction thereof
from the end of the blade root to an intermediate part of the shank; and
a plurality of normal blades provided with a blade root that is slotted into a blade
groove formed on the circumferential portion of the turbine disc to hold the whole
blade, a blade portion that is exposed to high-temperature gas, a platform that supports
this blade portion, a shank that connects the blade root and the platform, and a shroud
that extends along the circumferential direction from the end of the blade portion;
into the turbine disc to complete the turbine rotor, the method for constructing the
turbine rotor comprising,
a step of positioning the turbine rotor blade between the normal blades by moving
the turbine rotor blade radially inward from radially outward, between the normal
blades whose blade roots have been slotted into the blade grooves on the turbine disc
to a predetermined depth, and thereafter, slotting the blade roots of the turbine
rotor blade and the normal blades into the blade grooves on the turbine disc by moving
the turbine rotor blade and the normal blades in the axis line direction of the turbine
rotor.