JPH045681Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a connecting plate damper inserted into a gap between a blade at the tip of a turbine rotor blade and a shroud.

[Conventional technology]

The steam flow is applied as an excitation force to the turbine rotor blades while a large centrifugal force is acting on them due to high speed rotation. Therefore, the strength of the turbine rotor blades is determined by the vibration strength. The magnitude of vibration stress is influenced by the magnitude of damping in the system, and conventional rotor blades are generally composed of a group of several blades connected by a shroud. This is called a finite wing group. In order to increase the damping of the system, connecting plate dampers are provided between the blade groups. Not only does the connecting plate damper increase damping, but it also has the vibration characteristics of an infinite group of blades with a continuous shroud all around it, resulting in benefits such as fewer dangerous resonance points.

Therefore, in conventional turbines, as shown in FIGS. 5 to 9, a connecting plate damper 01 is installed in the gap between the tip of the blade 04 of the turbine rotor blade and the shroud 03. A tenon 02 is protruded from the top of the blade, and multiple blades 04 are bound together with a single shroud 03.
The connecting plate damper 01 is for connecting the end blades 04 of adjacent blades.
For installation, the two tenon insertion holes 06 provided in the connection plate damper 01 are inserted into the tenons 02 of both adjacent blades 04, and the shroud 03 is placed on each blade. Caulk the head of Tenon 02. Note that the connection plate damper 0
1 is installed with shroud 0 for the reasons mentioned above.
There are advantages such as a damping effect due to the relative slip between the blades and the blades, and the ability to maintain the vibration characteristics of the infinite blade group and reduce dangerous resonance points by connecting the blades all around. However, since the above-mentioned conventional connecting plate damper 01 is attached to the head of the tenon 02, once it is assembled, it cannot be removed. Therefore, if even one of the connecting plate dampers 01 is damaged, the tenon It is necessary to replace all the blades 04 that are integrated with the blades 02 with new ones, and the disadvantage that this case inevitably increases the cost is unavoidable.

Therefore, in order to improve this drawback, the present inventors first invented a connecting plate damper having a two-part structure as shown in FIGS. 10 to 13.

This invention involves inserting a two-plate connecting plate damper 1 having an opening 2 and a stepped part 4 at the toes of the opening 2 from opposite directions, and then inserting the connecting plate damper 1 into Both ends can be fixed by means such as welding or bending, and while it has the same effect as a conventional connection plate damper, it can be removed by removing the fixed parts such as welded parts or bent parts. It's summery. This eliminates the need to replace the moving blade when replacing the connecting plate damper 1 when it is damaged.

In the figure, 3 indicates a tenon insertion hole, 5 indicates a tenon, 6 indicates a shroud, and 7 indicates a blade.

[Problem that the invention attempts to solve]

However, in the connecting plate damper 1 with this structure, 2
Since each of the connecting plate dampers 1 has an opening 2 on one side, when a tensile force is applied to the connecting plate damper 1 (i.e., when adjacent blade groups move apart), each connecting plate damper 1 A large stress acts on the beam portion 1C as a cantilever, and the connection plate damper 1
strength margin is reduced. Also, when fixing two connecting plate dampers 1 by welding, only a part of the tip of the beam can be welded due to space constraints.
The stress applied to the weld increases, and the strength margin of the weld decreases. As described above, compared to an integrated connection plate damper, the connection plate damper 1 having a two-part structure may have disadvantages such as lower strength.

Therefore, the purpose of the present invention is to provide a connecting plate damper which does not require replacing all the blades 04 by replacing only the damper 1 when the connecting plate damper 1 is damaged, and which has excellent strength. It's there to do.

[Means for solving problems]

In the present invention, two plates each having a tenon insertion opening and having stepped abutting portions are inserted from opposite directions through a dovetail joining means consisting of a protrusion and a dovetail groove, and the outer shape is adjusted. After being stacked so as to match and inserted, both ends can be fixed by means such as welding or bending, and the structure is such that it can ensure the same effect and strength as conventional connecting plate dampers. In addition, by removing fixed points such as welded portions or bent portions, the structure is such that it can be removed in the opposite direction.

[Effect]

In other words, the connecting plate damper according to the present invention can be installed in exactly the same manner as conventional dampers, and
When replacing the connecting plate damper, it can be easily done by removing the joint, pulling it out to the side, inserting a new damper from the side and rejoining it, and does not require replacing all the blades. .

Furthermore, the dovetail groove joining protrusions and grooves provided on the beams of the connecting plate damper have a two-part structure, so that they come into close contact with each other, so when a tensile force is applied to the connecting plate damper, each connecting plate damper Stress acts on the beam portion of the damper as it is a beam fixed at both ends, and the strength decreases less than that of an integrated connecting plate damper.

〔Example〕

Next, one embodiment of the present invention will be described. In FIGS. 1 and 4, a connecting plate damper 1 according to the present invention has an opening 2 for tenon insertion, and an opposite end of the opening 2. The two connecting plate dampers 1 shown in FIGS. 1 and 4, which are formed to have stepped portions 4 at the sides, are combined with the protrusions 8 and grooves 9 provided on the beam portions 7 in opposite directions, and the connecting plates are assembled. The ends of the damper 1 are fixed by means such as welding or bending, and it is possible to reproduce the same effect and strength as the conventional connecting plate damper.

Note that the stepped portion 4 is formed to have a thickness including the plate thickness of the opening insertion portion. That is, if the thickness of the stepped part 4 is the same as the thickness of the mating plate, the tenon 5
This increases the contact area with the material and contributes to damping vibrations.

The connection plate damper 1, which is constructed by inserting and fixing from the side in this way, is inserted in a similar manner to the conventional connection plate damper described above, as shown in FIGS. 2 and 3. I can do it. In addition, in the unlikely event that the connecting plate damper 1 is damaged and it becomes necessary to remove it, it can be pulled out to the side by removing the fixed parts such as welded parts or bent parts. It is possible to leave.

In the drawings, the same reference numerals as those in FIGS. 10 to 13 showing the conventional example indicate the same members.

[Effect of idea]

By fitting the protrusions and grooves provided on the beams of a connecting plate damper with a two-part structure into each other, even if a tensile force is applied to the connecting plate damper, the stress acting on the beams of the connecting plate damper is large. First, the strength margin of the connecting plate damper is increased. This is because stress as a cantilever beam does not act on the beam portion, but stress as a beam fixed at both ends acts on the beam portion.

As mentioned above, the present invention has many advantages in terms of vibration resistance, and the connecting plate damper can be installed and removed very easily, making repairs easy, and therefore eliminating the need to replace the blades around the entire circumference. This can significantly reduce repair costs, and can also be applied to existing blades.
Its strength and reliability can be significantly improved. Also,
The damping effect can also be dramatically improved compared to conventional ones.

Furthermore, in the unlikely event that the vibration characteristics of the infinite blade group are lost due to an accident in which the connecting plate damper flies off, the structure of the infinite blade group connected all around the circumference during the rotational vibration test before delivery of the actual aircraft based on phase determination, Application of the connecting plate damper according to the present invention to confirm overall reliability by conducting various tests such as a semi-infinite blade group structure in which two or three connecting plate dampers are removed, and a finite blade group structure in which all connecting plate dampers are removed. Therefore, the present invention has many practical benefits, such as being extremely easy and reliable, and will greatly contribute to the development of industry.

[Brief explanation of the drawing]

1 to 4 are diagrams showing one embodiment of the present invention, FIG. 1 is a perspective view showing the main parts of one embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing one embodiment of the present invention. FIG. 2 is a plan view and a side view showing an example of joining of a pair of connection plate dampers according to an embodiment. FIG. 4 is a perspective view of the main parts of the connection plate damper viewed from above. 5 to 9 are views showing the first conventional example, FIG. 5 is a front view of the main assembly parts of the conventional connecting plate damper, and FIGS. 6 and 7 are views of the conventional connecting plate damper. FIGS. 8 and 9 are a longitudinal sectional side view and a plan view, respectively, and a plan view and a side view of a connecting plate damper showing a first conventional example. 10 to 13 are diagrams showing the second conventional example, in which FIG. 10 is a perspective view of the connecting plate damper, and FIG.
Figures 1 and 12 are a plan view and a side view showing how a pair of connecting plate dampers are joined, and Figure 13 is a vertical cross section of the main part showing the connecting plate damper installed in the gap between the blade and the shroud. It is a diagram. 1... Connecting plate damper, 2... Opening, 3... Tenon insertion hole, 4... Stepped part, 7... Beam part, 8...
Protrusion, 9...groove.

Claims (1)

[Scope of utility model registration request] In a connecting plate damper that is inserted into a gap between a blade at the tip of a turbine rotor blade and a shroud and is engaged with a tenon of the blade, an opening is opened laterally from a deep part of the connecting plate damper to be engaged with the tenon of the blade. A connecting plate damper characterized in that the above-mentioned connecting plate dampers having a tenon insertion opening and a stepped portion protruding from the toe of the tenon insertion opening are stacked in opposite directions and joined by dovetail groove joining means. .