JP2001200703A - Turbine rotor blade and turbine assembling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower vibration response of blades, simplify the assembling, and lower the manufacturing cost by forming an endless blade which is capable of surely coupling between adjacent blades, using a simple structure. SOLUTION: A clearance is provided in a periphery side of a groove of a disk, into which a blade root part is to be inserted, so that the blade root part can be tilted in the circumferential direction. When assembling the blades, the blade is tilted for assembling, while utilizing this clearance so as to simplify the assembling process. During the operation, the rotor blades are raised by the centrifugal force and shelves of the upper ends of adjacent profile parts form an endless blade while eliminating the clearance, and vibration response of the blade can be lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine blade having an integral shroud blade (ISB) structure applied to an axial flow turbine such as a steam turbine and a gas turbine. Things.

[0002]

2. Description of the Related Art An outline of a conventional short-wing integral shroud blade will be described with reference to FIGS. Figure 5 shows a conventional short wing integral shroud wing (ISB).
FIG. 6 is a perspective view showing a single rotor blade shown in FIG. 5, and FIG. 7 is a perspective view showing one of the rotor blades shown in FIG.
It is an arrow view.

As shown in FIGS. 5 to 7, a moving blade 1 has a profile portion 2 and a blade root portion 3, and a shelf 4 is integrally formed on the upper end of the profile portion 2 by an appropriate fixing means such as welding. It is attached and configured.

On the other hand, a disk 6 forming the rotor of the turbine is provided with a groove 7 into which the blade root 3 is inserted.
The blades 3 of the moving blade 1 are inserted into the groove 7 from the axial direction, so that adjacent moving blades 1 are sequentially assembled.

[0005] The rotor blade 1 assembled in this manner is:
As shown in FIG. 7, the end faces 5 of the adjacent moving blades 1 that face each other in the circumferential direction of the shelves 4 are closely contacted and coupled, so that the vibration response of the moving blades 1 is reduced.

[0006]

However, the following problems have been encountered with the conventional turbine rotor blades composed of short blade integral shroud blades as described above.

1: The centrifugal force generated during operation reduces the load.
The diameter of the blade increases, and a small gap is created on the shelf of the adjacent wing,
If this spreads, a coupling effect cannot be expected, and the vibration response of the blade tends to increase.

2: In order to provide a coupling effect in a centrifugal force field, the end surfaces of the shelves at the tops of the blades need to be brought into close contact with each other by performing a precise grinding process, and forcibly twisting the profile portions. It is necessary to devise such means as incorporating the wings that have given the wings, and these factors have caused a cost increase.

The present invention eliminates the disadvantages of the conventional turbine blade and reduces the vibration response of the blade by forming an infinite blade having a simple configuration and capable of securely coupling adjacent blades to each other. It is another object of the present invention to provide a turbine rotor blade which can be assembled easily and the production cost can be reduced.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. As a first means, a moving blade comprising a profile portion, a blade root portion, and a shelf at an upper end of the profile portion is provided. In a turbine rotor blade configured to be integrated along the entire circumference adjacent to each other in the circumferential direction of the disk,
On the outer peripheral side of the groove of the disk into which the blade root is inserted,
It is an object of the present invention to provide a turbine rotor blade provided with a clearance in which the blade root can tilt in the circumferential direction.

In other words, according to the first means, the clearance formed on the disk for inserting the blade root is provided on the outer peripheral side thereof so that the blade root can be tilted in the circumferential direction. When installing the blade, the clearance is used to incline the blade so as to simplify the assembling process. In addition, during operation, the blade is raised by centrifugal force and the shelf at the upper end of the adjacent profile portion is raised. And a shelf constitute an infinite blade with no gap, thereby reducing the vibration response of the blade.

Further, the present invention provides, as a second means, the first means.
In the above-mentioned means, the blade root portion has a base portion formed in a circular cross-sectional shape, and the groove of the disk provides a turbine rotor blade formed in a shape matching at least the outer peripheral side with the base portion.

According to the second means, the root of the blade inserted into the groove formed in the disk has its base formed in a circular cross section, while the groove for receiving the base having the circular cross section has at least a groove. On the outer peripheral side, the shape of the base is adjusted to a circular cross-sectional shape, so that the assembly process of inserting the blade root into the groove can proceed smoothly, and in addition to the blade root base by centrifugal force during operation. And the grooves are well matched to form a suitable infinite wing to reduce the vibration response of the wing.

Further, the present invention provides, as a third means, the first means.
In the means, the blade root has a base formed in a polygonal cross-sectional shape, and the groove of the disc provides a turbine rotor blade formed in a shape matching at least the outer peripheral side with the base.

In other words, according to the third means, the root of the blade inserted into the groove formed in the disk has its base formed in a polygonal cross section, while the groove for receiving this polygonal cross section base is formed. At least on the outer peripheral side, the base portion has a shape that matches the polygonal cross-sectional shape, so that the assembly process of inserting the blade root portion into the groove is particularly stable and smooth, and during operation, The blade root base and the groove are well aligned by centrifugal force, and a suitable infinite blade is formed to reduce the vibration response of the blade.

Further, the present invention provides, as a fourth means, the first means.
In any one of the third means to the third means, the shelf at the upper end of the profile portion may be configured such that an end surface facing the shelf at the upper end of the profile portion of the adjacent turbine blade is inclined with respect to the diameter direction of the disk. -To provide a bin bucket.

That is, according to the fourth means, the shelf provided at the upper end of the profile portion has an end surface facing the shelf provided at the upper end of the adjacent profile portion, the end surface being inclined with respect to the diameter direction of the disk. Therefore, the blade having the blade root portion inserted into the groove of the disk has improved adhesion between adjacent shelves during operation, thereby strengthening the coupling of the blade.

Further, the present invention provides, as a fifth means, a method in which a clearance is provided on the outer peripheral side of the disk so that the blade root can tilt in the circumferential direction. And a method for assembling a turbine that is inserted from the side of the turbine.

That is, according to the fifth means, a clearance is provided in the groove of the disk in which the blade root is to be incorporated, on the outer peripheral side thereof, so that the blade root can tilt in the circumferential direction. Since the rotor blades are inserted from the side surface of the disk in an inclined state and assembled, the rotor blades can be easily and appropriately incorporated into the disk.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1A and 1B are partial schematic views of a turbine rotor blade according to the present embodiment, in which FIG. 1A shows an assembling process, FIG. 1B shows an operating state, and FIG.
(A) is a schematic view of the main part of FIG.
1B corresponds to FIG. 1B, respectively, and FIG. 3 is a partial view showing a shelf shape partially modified in the present embodiment.

In order to avoid redundant description, the same parts as those of the prior art described above are denoted by the same reference numerals in the drawings, and redundant description is omitted as much as possible. The points that are unique to are described below.

That is, in the present embodiment, the moving blade 1
Is different from the blade root portion 3 provided on the conventional rotor blade 1 in the shape thereof, and is provided with a blade root portion 11 formed in a circular cross section. During operation, the moving blades 1 are raised by centrifugal force, and the shelves 4 of the adjacent moving blades 1 are coupled with each other without gaps, thereby forming an infinite blade.

In FIG. 1, each blade 1 is composed of a profile portion 2, a blade root portion 11 having a circular cross section at the base, and a shelf 4 integrally attached to an upper end of the profile portion 2 by appropriate fixing means such as welding. Have been.

On the outer peripheral side of the groove 12 into which the blade root 11 is inserted, a clearance C is provided so that the blade root 11 can tilt in the circumferential direction. As shown in FIG. 1A, the blade root 11 is inserted into the groove 12 in a state where the blade root 11 is inclined at a predetermined angle θ with respect to the diametrical direction of the disk 6, and is assembled. In addition,
At the time of this assembling, a gap Sa is provided between the shelf 4 of one of the moving blades 1 and the shelf 4 of the moving blade 1 adjacent thereto.

During operation, the disk 6 and the rotor blade 1 which form the rotor by centrifugal force extend, and the circumferential pitch of the blade top of the rotor blade 1 increases, but as shown in FIG. Due to the force, the rotor blade 1 rises around the circular cross-section of the blade root 11 as an axis, and the gap between the adjacent shelves 4 disappears, and the end face 5
Are in close contact, and this close contact forms an infinite wing.

That is, in the present embodiment, the moving blade 1 integrally provided with the profile part 2, the blade root part 11, and the shelf 4 is arranged so that the rotor 6 forms a rotor from the side of the disk 6. Are inserted in the axial direction while being inclined in the circumferential direction, so that the adjacent moving blades 1 are sequentially assembled.

The turbine rotor thus constructed has a gap Sa between the shelves 4 to 4 of the adjacent rotor blades 1 at the time of assembling. When the moving blade 1 rises as the height rises and a predetermined centrifugal force field is generated, the gap S between the adjacent shelves 4 to 4 substantially adheres to each other or becomes equal to the close contact. Bucket 1
Are coupled.

By this coupling, an infinite blade in which the moving blades 1 incorporated around the entire circumference of the disk 6 are grouped can be achieved at a low cost, and the vibration response level during operation is suppressed by the infinite blade. can do.

Here, the change in the shelf length Pa at the time of installation and the change in the shelf length P during operation will be described with reference to FIG.

Assuming that the shelf length Pa at the time of installation is the shelf length P during operation and the inclination angle θ of the moving blade with respect to the diameter direction of the disk, Pa = Pcos θ ... (1) The difference δ between the circumferential length at the time of installation and the circumferential length during operation is δ = {P / π (D + 2h)} × [π (D + 2h) −π (D + 2hCOSθ) ] = {P × 2h / (D + 2h)} × (1−COSθ) (2) where δ takes into account only the geometric length and ignores elongation due to stress. . D represents the diameter of the disk regulated by the position where the disk and the blade root are locked, and h represents the blade length from the diameter D to the shelf at the tip of the profile portion.

Therefore, when the rotor blade 1 rises due to the centrifugal force during operation, the gap χ is reduced by (1)
From equation (2), it can be obtained as follows.

Χ = (P−Pa) −δ = P (1−cos θ) − {P × 2h / (D + 2h)} (1−COSθ) = P (1−cos θ) × D / (D + 2h) Thus, the amount す る by which the gap is reduced by appropriately setting the shelf length P and the inclination angle θ is obtained. In the drawing, χ = Sa−S.

The gap S during operation is infinitely close to 0 (zero), and it is preferable that the gaps S are in close contact with each other. However, the gap S is substantially smaller than the allowable vibration response amplitude of the moving blade 1 during operation. This is equivalent to the close contact state, and a coupling effect can be obtained.

Also, as shown in FIG. 3, both ends of the shelf 4 at the upper end of the profile portion 2 have inclined end surfaces 5 having an inclined angle φ.
a, the gap Sa at the time of assembling is formed.
Can be set small, and there is an effect that the adhesion between adjacent shelves during operation is further improved and the coupling of the moving blades is further strengthened.

If fluid leakage from the gap between the groove 12 and the blade root 11 cannot be ignored, a baffle plate or the like (not shown) is attached to the side of the disk 6 forming the rotor to reduce the fluid leakage. Can be prevented.

As described above, according to the present embodiment, the blade root 11
Is formed in a circular cross-section, and it is inclined and assembled during assembly.
During operation, the rotor blades rise due to the centrifugal force, and the infinite blades with no gaps in the shelf can be formed at low cost. By configuring the infinite wing, the vibration response level of the moving blade can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. FIG. 4 is a schematic view of a turbine rotor blade according to the present embodiment.
(B) shows the operating state.

In order to avoid redundant description, the same parts as those of the above-described conventional one and the first embodiment are denoted by the same reference numerals in the drawings, and the repeated description is omitted. A description will be given with emphasis on points that are unique to the present embodiment, as much as possible.

That is, this embodiment is different from the first embodiment in that the shape of the blade root portion and the groove into which the blade root portion is inserted is changed, and the base portion of the blade root portion has a substantially convex cross section. It is formed into a polygonal cross-sectional shape, and during assembly, the blades are installed inclined with respect to the disk diameter direction, and during operation, the blades rise due to centrifugal force, and the adjacent blades are coupled without gaps and infinite It is constructed so that wings can be made.

In FIG. 4, each blade 1 is integrally formed with a profile portion 2, a blade root portion 21 having a polygonal cross-sectional shape whose base portion has a substantially convex cross-sectional shape, and an appropriate fixing means such as welding at the upper end of the profile portion 2. And a shelf 4 mounted on the shelf.

On the outer peripheral side of the groove 22 into which the blade root 21 is inserted, a clearance C is provided so that the blade root 21 can tilt in the circumferential direction. Then, as shown in FIG. 4A, the blade root 21 is inserted into the groove 22 while being inclined at a predetermined angle θ with respect to the diametrical direction of the disk 6, and is assembled. In addition,
At the time of this assembling, between the shelf 4 of one of the moving blades 1 and the shelf 4 of the moving blade 1 adjacent thereto, end faces 5 to 5 facing each other in the circumferential direction.
There is a gap Sa between them.

During operation, as shown in FIG. 4 (b), the substantially convex cross section of the blade root 21 rotates in the groove 22 due to centrifugal force, and the rotor blade 1 rises, and the centrifugal force field during operation is raised. At
The disk 6 and the rotor blade 1 forming the rotor are extended, and the rotor blade 1
The gap between the adjacent one of the shelves 4 and the other one of the shelves 4 is reduced, so that a coupling effect can be obtained. The infinite wing is constituted by.

That is, in the present embodiment, FIG.
As shown in (a), the profile portion 2 and the blade root portion 21
And the moving blade 1 integrally provided with the shelf 4 is inserted into the groove 22 in the axial direction while being inclined in the circumferential direction of the disk 6 from the side surface of the disk 6 forming the rotor. As a result, the adjacent moving blades 1 are sequentially assembled.

The turbine rotor of the present embodiment thus constructed has a gap Sa between the shelves 4 to 4 of the adjacent rotor blades 1 at the time of assembly. When the rotor 1 rises as the rotation of the rotor 6 rises and a predetermined centrifugal force field is generated, the gap S between the adjacent shelves 4 to 4 becomes smaller and finally comes into close contact, and each rotor 1 is connected. Is done.

By this coupling, an infinite blade in which the moving blades 1 incorporated over the entire circumference of the disk 6 are grouped can be achieved at a low cost, and the vibration response level during operation is suppressed by the infinite blade. can do.

Although not shown in the drawings, both ends of the shelf 4 at the upper end of the profile portion 2 are fixed at a fixed inclination angle φ in the same manner as described with reference to FIG. 3 as a partial modification of the first embodiment.
The gap Sa at the time of installation can be set small, and the adhesion between adjacent shelves during operation can be further improved, and the coupling of the moving blades can be further strengthened. is there.

If fluid leakage from the gap between the groove 22 and the blade root 21 cannot be ignored, a baffle plate or the like (such as a baffle plate) may be provided on the side surface of the disk 6 forming the rotor as in the first embodiment. (Not shown) can be attached to prevent fluid leakage.

Thus, also in the present embodiment, as in the first embodiment, at the time of assembling, it is assembled while being inclined.
During operation, the rotor blades rise due to the centrifugal force, and the infinite blades with no gaps in the shelf can be formed at low cost. By configuring the infinite wing, the vibration response level of the moving blade can be reduced.

Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to this embodiment.
It goes without saying that various changes may be made to the specific structure within the scope of the present invention.

[0050]

As described above, according to the first aspect of the present invention,
A turbine blade comprising a profile portion, a blade root portion, and a blade at an upper end of the profile portion, which are adjacently arranged in the circumferential direction of the disk and are integrated over the entire circumference, wherein the blade root portion is inserted. The turbine blade is formed by providing a clearance on the outer peripheral side of the groove of the disk to allow the root of the blade to tilt in the circumferential direction, so that when the blade is incorporated, the blade is used by using the clearance. The blade is raised by centrifugal force during operation, and the shelf at the upper end of the adjacent profile section forms an infinite blade with no gap, and the vibration response of the blade Thus, it is possible to obtain a suitable turbine blade having high safety and reliability, facilitating assembly work and the like, and reducing costs.

According to a second aspect of the present invention, in the first aspect of the present invention, the blade root has a base formed in a circular cross-sectional shape, and the groove of the disk is formed at least with the base. Since the turbine blade is formed so as to be aligned on the outer periphery side, the turbine rotor blade is formed. Therefore, the assembling step of inserting the blade root portion into the groove by the base having the same circular cross section and the groove receiving the base in alignment with the base. In addition to being smoothly advanced, the blade root base and the groove are well aligned by centrifugal force during operation, forming a suitable infinite wing, achieving a reduction in blade vibration response,
As a result, a suitable turbine blade having high safety and reliability, facilitating assembly work and the like, and reducing costs can be obtained.

According to a third aspect of the present invention, in the first aspect of the present invention, the blade root portion has a base formed in a polygonal cross section, and the groove of the disk is formed in the base with the base. Since the turbine blade is formed at least on the outer peripheral side so as to be aligned with the outer peripheral side, the blade root portion is inserted into the groove by the base having the polygonal cross section and the groove receiving the base in alignment with the base. In addition to the stable and smooth assembly process, centrifugal force aligns well with the root of the blade during operation, forming a suitable infinite wing and reducing the vibration response of the wing. As a result, a suitable turbine blade having high safety and reliability, facilitating the assembling work, and reducing the cost can be obtained.

According to the invention set forth in claim 4, in the invention set forth in any one of claims 1 to 3, the shelf at the upper end of the profile portion is provided at the upper end of the profile portion of the adjacent turbine blade. Of the disk is configured to be a turbine blade inclined with respect to the diametric direction of the disk, and the blade root is inserted into the groove of the disk by the end surface inclined with respect to the diametric direction of the disk. The rotor blades have improved adhesion between adjacent shelves during operation, achieve stronger coupling of the rotor blades, and have higher safety and reliability, as well as easier assembly work and reduced costs. A simple turbine blade was obtained.

Further, according to the fifth aspect of the present invention, the blade is inclined in the radial direction of the disk in the groove of the disk provided with a clearance on the outer peripheral side where the blade root can tilt in the circumferential direction. Since the turbine is assembled by inserting the disk from the side and assembling the blade, the blades can be easily and appropriately assembled to the disk while being inclined with respect to the diameter direction of the disk. Thus, it is possible to obtain a suitable turbine assembling method which has high safety and reliability, facilitates assembling work and the like, and reduces costs.

[Brief description of the drawings]

FIGS. 1A and 1B are partial schematic views of a turbine rotor blade according to a first embodiment of the present invention, wherein FIG. 1A shows an assembling process, and FIG.
Indicates an operating state.

FIGS. 2A and 2B are schematic views showing the main parts of FIG. 1; FIG.
(A) and (b) respectively correspond to (b) of FIG. 1 and show an assembling process and an operating state.

FIG. 3 is a partial view showing a shelf shape partially modified in the first embodiment of FIG. 1;

FIGS. 4A and 4B are partial schematic views of a turbine blade according to a second embodiment of the present invention, wherein FIG. 4A shows an assembling process and FIG.
Indicates an operating state.

FIG. 5 is a partial schematic view of a turbine rotor blade configured by a conventional short blade integral shroud blade.

FIG. 6 is a perspective view showing one rotor blade extracted from FIG. 5;

FIG. 7 is a view taken in the direction of arrows VII-VII in FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 rotor blade 2 profile part 3 blade root part 4 shelf 5 end face 6 disk 7 groove 11 blade root part 12 groove 21 blade root part 22 groove C clearance S gap Sa gap

Claims (5)

[Claims] 1. A turbine rotor comprising a blade comprising a profile part, a blade root part and a shelf at the upper end of the profile part, which are adjacent to each other in the circumferential direction of the disk and are integrated over the entire circumference. A turbine rotor blade provided with a clearance on an outer peripheral side of a groove of the disk into which the blade root is inserted so that the blade root can tilt in a circumferential direction. 2. The taper according to claim 1, wherein the blade root has a base formed in a circular cross-sectional shape, and the groove of the disk has a shape that matches the base at least on the outer peripheral side. -Bin buckets. 3. The blade root portion has a base formed in a polygonal cross-sectional shape, and the groove of the disk is formed in a shape that matches the base at least on the outer peripheral side.
3. The turbine blade according to item 1. 4. An end face of the upper end of the profile portion facing the upper end of the profile portion of the adjacent turbine blade is inclined with respect to the diameter direction of the disk. Item 4. The turbine blade according to any one of Items 1 to 3. 5. Assembling by inserting a blade into a groove of a disk provided with a clearance on an outer peripheral side of a blade in which a blade root can be tilted in a circumferential direction, from a side surface of the disk with the blade being inclined with respect to a diameter direction of the disk. A turbine assembling method characterized by the above-mentioned.