JPH07279606A - Turbine moving blade device - Google Patents

Abstract

PURPOSE:To facilitate unbalance adjustment of a rotary body so as to reduce its processing manhours by forming connection between the disc of a rotary shaft and a moving blade in ruggedness fitting and arranging a stop blade on one part in a peripheral direction and also forming a shroud positioned in a specific direction from the arranged position of the stop blade lighter than the other shrouds. CONSTITUTION:Each moving blade 1 and each moving blade 2 to be a stop blade (or stop metal 3) are fixed on a rotary disc 5 by stop keys 4. Certain numbers of the moving blades 1 and the moving blades 2 to be the stop blades are combined together entire periiphery and connected to each other across its by the shroud 6. In this case, the material of the shroud 7 positioned in 180 deg. direction of the moving blade 2 to be the stop blade (stop metal 3) is made lighter than those of the other shrouds 6 by making it of, for example, titanium alloy. Thus, its unbalance is reduced and its weight is adjusted by changing the weight of a shroud 7. As the shroud is affected by a centrifugal force greatly, its regulation range becomes wide and its adjust is easy due to its location outside of the rotary body. Therefore, its adjustment can be made easy, its processing manhours can be reduced and its unbalance can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a turbine rotor blade device, and more particularly to an improvement in a turbine rotor blade device having a shroud on the outer periphery of the rotor blade.

[0002]

2. Description of the Related Art As shown in FIG. 5, a moving blade device such as a steam turbine generally used in the past has a plurality of moving blades having various effective lengths and sizes depending on steam conditions. It is composed of paragraphs.

This drawing is a view in which the turbine impeller is sectioned in the axial direction, and high-temperature and high-pressure working steam jets from the left side to the right side in the figure. Therefore, as a matter of course, the first paragraph comes into contact with the vapor having the highest pressure and the highest temperature, and the vapor having the lower pressure and temperature comes closer to the right paragraph.

As described above, since the first paragraph contains high-pressure and dense steam, this section is formed to have a short blade length, and the blade length of the paragraph becomes smaller as it goes downstream in the steam flow. It is formed to be long. That is, the structure is such that the expanding steam can be received most efficiently.

In each of the paragraphs, the moving blade 1 is fitted and assembled on the outer circumference of the rotary disk 5 provided on the rotary shaft 11, and the shroud 6 is further provided on the outer circumference of the moving blade 1. With this shroud, the rotor blades 1 arranged around the entire circumference are connected to each other to form a robust structure.

When assembling the rotor blade 1, as shown in the exploded view of FIGS. 6 to 8, one blade is formed along the circumference from the groove S0 provided in the rotary disk of the rotary shaft. The blades 2 (or the clasps 3), which are to be the stop blades, are finally planted.

The moving blade 2 (or clasp 3) that serves as this retaining blade
The groove portion of the rotating disk is shaped to match the shape of the groove-free portion of the rotating disk, and the fixing of the moving blade 2 is performed by the two moving blades 1 adjacent to both sides of the moving blade and each of them. Holes are provided at a total of four positions between the moving blades adjacent to the moving blade 1 of No. 1 and fixed by inserting a key there. Then, after the moving blades are assembled, the above-mentioned shroud 6 is fitted to the outer circumferences of these moving blades.

In the moving blade device thus formed,
Since the moving blade 2 serving as the above-mentioned stop blade has a different weight from the other moving blades 1 due to the relationship of the hook groove, an imbalance occurs during rotation.

That is, in the moving blade 2 which is the stop blade,
The groove has an unbalanced shape with respect to the other moving blades, and the slanted portion is not processed. In addition, in the clasp 3, in addition to the moving blade 2 serving as the stopping blade, the blade portion is deleted. Since it has a curved shape, the imbalance becomes larger than that of the moving blade 2 that serves as a stop blade. The small-pitch moving blade shown in FIG. 8 will be called a small-pitch moving blade, and the large-pitch moving blade will be called a large-pitch moving blade.

When the clasp is adopted, as shown in FIG. 9, the small pitch moving blade 10 is arranged on the clasp side, and the large pitch moving blade 11 is arranged on the opposite side of the clasp. Since the small pitch rotor blade 10 has a small pitch, it is naturally possible to plant a large number of rotor blades.
On the contrary, as many blades as the small pitch blade 10 cannot be planted.

The weight difference per one moving blade due to the pitch difference of the groove portions shown in FIGS. 7 to 9 is minute, and the larger the number of blades is, the more weight can be earned. Therefore, by arranging the small-pitch moving blade 10 on the stopper side and increasing the number of blades on the stopper side, the imbalance due to the absence of the blade portion on the stopper side is compensated (on the stopper side). Compensating for the weight without the wings).

However, the imbalance cannot be completely eliminated only by such an operation. Therefore, some of the moving blades located on the opposite side of the moving blade 2 which is generally a stationary blade are locally processed as shown in FIG. 7, that is, a groove is provided to adjust the weight. I try to reduce the imbalance. This locally processed portion is generally called an S groove.
In addition, as a thing related to this, JP-A-59-215
No. 904 publication is mentioned.

[0013]

It is true that such a rotor blade device having S-grooves for balancing eliminates the imbalance of the rotor, which is effective in this respect.
If there are many S-grooves in one paragraph, the blade 10
It also becomes a book, and since the turbine impeller is formed from a plurality of paragraphs, a large number of S grooves are machined as a whole.

Providing a large number of grooves in this way tends to waste a lot of time on the processing, especially the processing in consideration of balance adjustment, and also has the potential to scratch the groove wall or the like during processing. . In particular, since this groove portion is also a portion that supports the moving blade itself, it is the place where the stress is the highest, and it is not allowed to make a flaw, and it also affects the reliability of the product, that is, the turbine itself.

The present invention has been made in view of the above, and an object thereof is to easily adjust the balance and reduce the man-hours for processing to sufficiently eliminate the imbalance of the rotating body.
Another object of the present invention is to provide a turbine blade device of this kind that can improve the reliability of the turbine.

[0016]

That is, according to the present invention, the shroud positioned 180 ° from the position where the stop vane is arranged is formed to be lighter in weight than the shroud provided on the other moving blades. It is intended to achieve the intended purpose.

[0017]

In other words, in the rotor blade device thus formed, the balancing S groove that has been conventionally used is a groove portion at the end on the shaft center side of the rotor blade, whereas in the present invention, it is performed by the shroud, that is, the shroud. Since it is located at the tip of the rotor blade, it is greatly affected by centrifugal force, so its adjustment range is wide, and its adjustment is easy because the shroud is located on the outer circumference of the rotor, and especially when machining grooves or Since there is no cutting process and the like, it is possible to easily adjust and reduce the number of processing steps to sufficiently eliminate the imbalance of the rotating body and to improve the reliability of the turbine.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiments. One example is shown in FIG.

This figure shows the assembled state of the rotor blade and shroud from the axial direction. The rotor blade 1 and the rotor blade 2 (or stopper plate 3) to be the stopper blade are assembled on the rotating disk 5, The moving blade 2 (or the stopper plate 3) that serves as the stopper blade is fixed by a stopper key 4.

The moving blades 1 and the moving blades 2 serving as the stop blades are spliced together by a shroud 6 and are connected along the entire circumference. In this case, the moving blades 2 serving as the stop blades (stop 3). Of 180
The material of the shroud 7 located in the ° direction is made of a titanium alloy, for example, and is lighter than the other shrouds 6.

When a titanium alloy is used, it is more difficult to machine than conventional materials (usually 12Cr steel), but it is possible to improve the machining efficiency by optimizing the cutting tools and cutting specifications. There is no problem.

There are many titanium alloys, but the most typical one is Ti-6Al-4V alloy. Ti-6Al-
The specific gravity of the 4V alloy is approximately 57% of the specific gravity of the conventional material, but the strength is equivalent, and it is an excellent material with a high so-called specific strength, and can be said to be one of the materials most suitable for the present invention.

For the specific adjustment of the imbalance, the materials of the shroud may be selected and combined from those having different specific gravities, but the same material may be used by changing the thickness and the size. good. For example, since titanium alloy has high strength, the shroud thickness may be reduced to adjust the number of titanium alloy shrouds used.

As described above, by forming the shroud located on the anti-stop vane (clasp) side by using a material lighter than other shrouds and by changing the number of sheets used, the imbalance can be reduced and the S groove and The same effect can be obtained. That is,
Shroud 7 was used for weight adjustment by S groove processing.
The weight is adjusted by changing the weight of.

With this structure, since the shroud is located at the tip of the moving blade, it is greatly affected by centrifugal force, its adjustment range is wide, and there is no particular groove processing or cutting processing, and the number of man-hours is large. The effect is extremely large, such as reduction in size and improvement in reliability.

FIG. 2 is an axial view of the assembled state of the rotor blade and the shroud. One shroud 8 including the moving blade 2 that serves as the stop blade and one shroud 8 on the opposite side of 180 °
Make each plate thickness thicker than the other shrouds 6,
At the time of reassembling after the precise inspection, this time, by assembling a shroud having the same plate thickness as the other shrouds 6, the shoulder lowering of the blade portion is eliminated.

Since the plate thickness of the shroud 8 is made thick at the time of initial manufacturing, the height of the moving blade tenon is sufficient even after the disassembly, and the shroud 6 having the thin plate thickness (same as other shrouds) is used at the time of reassembly. If a shroud with a plate thickness is used, it can be reassembled without lowering the shoulder of the blade.

That is, in general, in a steam turbine, 8 to 10 years after its manufacture, the moving blades are extracted for precision inspection, but for that purpose, disassembly processing such as shroud cutting must be performed. After the detailed inspection, the blades are shoulder-shouldered and then reassembled with the shroud of the same material and the same thickness as in the initial manufacturing.

That is, as shown in FIG. 10, since the shroud is fixed by caulking the moving blade tenon portion,
When removing the blade, the shroud must be cut first, and then the caulked portion of the blade tenon portion must be cut off. Then, in order to assemble again after the precise inspection, the blade portion must be cut by 0.3 mm or more (normally 1.0 mm) and the caulking margin must be provided by ensuring the height of the blade tenon. This operation is called shoulder down. Then, after that, the shroud is fitted into the moving blade and the moving blade tenon is caulked to fix the shroud.

This series of operations is shown in FIG. Shoulder shoulders require advanced technology and a lot of time, and a great deal of manpower is required. Therefore, the shoulder lowering work is not desirable in manufacturing.

As described above, since the shoulder lowering process requires a high technology and a great deal of time, it is desirable to have a structure that can be reassembled without the shoulder lowering process. Since the shroud is fixed by caulking the moving blade tenon portion, the shroud is cut when the moving blade is removed and the moving blade tenon crimping portion is removed, so that the shroud cannot be assembled as it is. Therefore, the blades are lowered to secure the height of the tenon so that caulking can be performed. In the present invention, at the same time as the balance adjustment, what was conventionally reassembled by the shoulder lowering process of the moving blade can be reassembled without the shoulder lowering process by adjusting the plate thickness of the shroud.

In the case of the present invention, the plate thickness of the shroud on the entire circumference is made thick at the time of the initial manufacturing, and at the time of reassembling after the precise inspection, the shroud having a thinner plate thickness than the initial manufacturing is assembled.

FIG. 3 is an axial view of the assembled state of the rotor blade and the shroud. In order to increase the plate thickness of the shroud 8 on the entire circumference during manufacturing, a material that is lighter and has higher strength than conventional materials is required. Titanium alloy is one of the most suitable materials for it, and Ti-6A, which is the most typical of them,
It can be realized by adopting an 1-4V alloy.

As shown in this figure, at the time of initial manufacturing, the shroud 8 on the entire circumference is made of a titanium alloy to be thicker than the conventional material, and after the precision inspection of the groove portion, the conventional material is used to reduce the plate thickness, so that the entire rotor blade is manufactured. As a result, it is not necessary to lower the shoulder and reassembly is possible.

Further, as shown in FIG. 4, instead of increasing the plate thickness, two thin shrouds 9 are piled up to make the entire circumference, and when reassembling after a precise inspection, the single shroud 6 having the conventional plate thickness is used. You can Even in this case, the double shroud 9 is made of titanium alloy at the time of initial production, and it is 1 after the precise inspection of the groove.
The heavy conventional shroud 6 allows reassembly without shoulder down.

Conventionally, when the shoulder is lowered, the processing amount is 0.
Since it is 3 mm or more (usually 1.0 mm), in both the method of making the entire circumference a thick plate thickness and the method of making the entire circumference a double shroud at the time of initial production, it is 0 from the plate thickness when using the conventional material. It must be thicker than 3 mm.

Titanium alloy, particularly Ti-6Al-4V alloy, is an excellent material having a high specific strength and is about 57% of the specific gravity of the conventional material. Therefore, even if the plate thickness is increased to about 1.0 mm, it is centrifuged. The stress is never greater than that of conventional materials. For example, when using a conventional material and having a plate thickness of 4 mm, the titanium alloy is 5 mm even if the maximum is added by 1.0 mm.

Conventional material and titanium alloy both have the same area A,
Assuming only the plate thickness is different, the weight of the conventional material is 4 x A x
7.85 = 31.4A Weight of titanium alloy is 5 x A x
(7.85 x 0.57) = 22.4 A, the weight of titanium alloy is about 71% of the weight of conventional material, and the weight of shroud is light even if the plate thickness is increased by making titanium alloy. Therefore, there is also an advantage that the centrifugal stress due to the shroud becomes small.

[0039]

As described above, according to the present invention, the shroud positioned 180 ° from the position where the stop vane is arranged is formed to be lighter in weight than the shroud provided on the other moving blades and is adjusted. Since the shroud is located at the tip of the rotor blade, the influence of centrifugal force is large, so the adjustment range is wide, and because the shroud is located on the outer circumference of the rotating body, the adjustment is easy. Further, there is no particular groove processing or cutting processing, and therefore, it is possible to obtain a turbine moving blade device of this type that can be easily adjusted and the number of processing steps can be reduced to sufficiently eliminate the imbalance of the rotating body and improve the reliability of the turbine. You can

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a turbine blade device of the present invention.

FIG. 2 is a front view showing another embodiment of the turbine rotor blade device of the present invention.

FIG. 3 is a front view showing another embodiment of the turbine rotor blade device of the present invention.

FIG. 4 is a front view showing another embodiment of the turbine rotor blade device of the present invention.

FIG. 5 is a side view of a turbine blade device.

FIG. 6 is an exploded perspective view of a rotating disk, a moving blade, and a shroud.

FIG. 7 is a perspective view showing a single moving blade.

FIG. 8 is a side view showing a single moving blade.

FIG. 9 is an array diagram of moving blades when a clasp is adopted.

FIG. 10 is a perspective view showing a main part of a turbine blade device.

FIG. 11 is a perspective view showing a series of operations from disassembly to reassembly of the turbine blade device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Moving blade, 2 ... Stopper, 3 ... Stopper, 4 ... Key, 5 ... Rotating disk, 6 ... Shroud, 7 ... Shroud on the opposite side of the stop vane (stop), 8 ... Shroud thicker than shroud 6 , 9 ... 2
Heavy shroud, 10 ... Small pitch blade, 11 ... Large pitch blade.

Claims (8)

[Claims] 1. A plurality of moving blades assembled on the outer circumference of a disk of a rotating shaft, and a shroud provided on the outer circumference of the moving blades so as to connect adjacent moving blades to each other. In a turbine moving device in which the blades are coupled by concave and convex fitting, and the stopper blades are arranged in a part of the circumferential direction, the turbine rotor blade device is located 180 ° from the position where the stopper blades are arranged. A turbine blade device characterized in that a shroud is formed to be lighter in weight than other shrouds. 2. A plurality of moving blades assembled on the outer circumference of a disc of a rotating shaft, and a shroud provided on the outer circumference of the moving blades so as to connect adjacent moving blades to each other. In a turbine moving blade device in which coupling with a blade is performed by concavo-convex fitting, and a stationary blade is arranged in a part of a circumferential direction, a shroud of a moving blade arranged on the opposite side of the stationary blade, A turbine moving blade device characterized in that it is made of a material lighter than the material used for the shroud of other moving blades. 3. A turbine moving blade device according to claim 1, wherein the shroud arranged on the stationary blade side and the shroud arranged on the other moving blade side are formed to have the same thickness. 4. A plurality of moving blades assembled on the outer circumference of a disk of a rotating shaft, and a shroud provided on the outer circumference of the moving blades so as to connect adjacent moving blades to each other. A turbine moving blade device in which a blade is coupled to a blade by concavo-convex fitting, and a stopper blade for preventing movement of the moving blade in the circumferential direction is disposed in a part of the circumferential direction, wherein Side shroud and the material used for the shroud of the other blade are made of the same material, and the shroud of the rotor blade arranged on the opposite side in the circumferential direction of the stop blade is A turbine moving blade device characterized in that it is formed thinner than the shroud of another moving blade. 5. The shroud disposed on the stop blade side is formed of 12Cr steel, and the shroud disposed on the other moving blade side is formed of a titanium alloy.
The turbine moving blade device according to 2, 3, or 4. 6. A plurality of moving blades assembled on the outer circumference of a disk of a rotating shaft, and a shroud provided on the outer circumference of the moving blade so as to connect adjacent moving blades, In a turbine blade device in which the blades are coupled by concave and convex fitting, and the stopper blades are arranged in a part of the circumferential direction, a shroud arranged on the stopper blade side is replaced with a shroud of another blade. A turbine moving blade device characterized by being formed of the same material as, and thicker than shrouds of other moving blades, and being made of a heavy material and having the same plate thickness as other shrouds when the shroud is replaced. 7. A plurality of moving blades assembled on the outer circumference of a disk of a rotating shaft, and a shroud provided on the outer circumference of the moving blade so as to connect adjacent moving blades to each other. In a turbine moving device in which coupling with a blade is performed by concavo-convex fitting, and a stop blade is arranged in a part in the circumferential direction, the shroud is formed by stacking a plurality of thin plates, and A turbine moving blade device characterized in that the number of shrouds of moving blades arranged on the opposite side is smaller than the number of shrouds provided on other moving blades. 8. A plurality of moving blades assembled on the outer circumference of a disk of a rotating shaft, and a shroud provided on the outer circumference of the moving blades so as to connect adjacent moving blades to each other. In a turbine moving blade device in which the blades are coupled by concavo-convex fitting, and the stopper blades are arranged in a part in the circumferential direction, the shroud is formed by stacking a plurality of thin plates, and One material is made of titanium alloy, and the number of shrouds of the moving blade arranged on the opposite side of the stop blade is smaller than the number of shrouds provided on the other moving blade. A turbine rotor blade device characterized by the above.