JPH10317907A - Compressor blade fixed structure - Google Patents

Abstract

(57) [Summary] A compressor blade is fixed to a rotor disk by a blade fixing part, and it is possible to prevent movement and dropping. However, a gap between a blade root portion and a fitting groove during operation of a gas turbine is provided. Through which the working fluid leaks and the efficiency of the compressor decreases. The above object is achieved by fixing a compressor blade with a blade fixing part having a retaining plate having a size larger than a gap between a blade root and a fitting groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine structure, and more particularly to a fixed structure of a compressor rotor blade.

[0002]

2. Description of the Related Art A rotor blade of an axial compressor of a gas turbine generally has a blade root portion called a dovetail at a root thereof, and is inserted into a fitting groove provided on an outer periphery of a rotor disk to reduce centrifugal force. Supported for. The centrifugal force described above is the largest force that acts on the compressor blades, but in addition, axial and circumferential forces due to the fluid force of the working air and forces due to vibration also act. Since these forces also have components in the direction of the fitting groove, there is a possibility that the compressor blades may fall out of the fitting groove during operation of the gas turbine, and a moving blade fixing structure for preventing proper removal is required. .

As such a moving blade fixing structure, there is a method of easily fixing the moving blade by inserting a moving blade root portion into a fitting groove of the rotor disk and then crimping an end of the fitting groove of the rotor disk. When the fluid force or the like increases with the increase in the output of the motor, the fixing by swaging is not sufficient.

In such a situation, a fixing method using another wing fixing part is used, and as a conventional technique, a moving blade fixing by a blade lock or the like described on page 75 of "Jet Engine (Structure)" published by Japan Aviation Technology Association. There is a structure. In this prior art, a blade fixed component called a blade lock is inserted into a gap between a blade root base and a rotor disk fitting groove, and then both ends are bent to prevent the blade from coming off.

[0005]

However, the present prior art makes it possible to prevent the compressor rotor blades from coming off in the axial direction of the fitting groove, but has the following problems. That is, the compressor is composed of multi-stage blades, and each blade compresses air as a working fluid. Therefore, since the pressure on the downstream side of each blade is higher than that on the upstream side, if there is a gap in the fitting portion, a backflow of air will occur through the gap, making it difficult to secure the sealing performance and reducing the efficiency. In the prior art, consideration for this sealing performance was not sufficient.

[0006]

An object of the present invention is to provide a shape of a retaining portion at an end of a blade fixed part, which is capable of covering a gap between a rotor blade root and a rotor disk fitting groove. It is achieved by combining different parts that can.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 7 shows one of the prior art embodiments. The compressor blade 1 has a blade root portion 2 usually called a dovetil at its root, is moved into the fitting groove 4 of the rotor disk 3 and is prevented from being scattered by centrifugal force. Since a gas bending force, a force due to a pressure difference, an oscillating stress, etc. act on the compressor blade 1 in addition to the centrifugal force,
Simply inserting the blade root 2 into the fitting groove 4 will not
Along the worst case and may fall off. Therefore, in the prior art, the compressor blade 1 is fixed to the rotor disk 3 by a blade fixing part 5 usually called a blade lock, and the retaining is prevented.

The wing fixing part 5 has a support portion 6 and retaining plates 7 and 8 at both ends thereof. Before assembling, only one of the retaining plates 7 is processed into a shape bent with respect to the support portion 6. is there.
To assemble, the main wing fixed part 5 is previously arranged in the fitting groove 4 of the rotor disk 3 from the outer peripheral part 9, and then the wing root part 2 of the compressor wing 1 is inserted from the unfolded side of the wing fixed part 5. And
The fixing of the compressor blade 1 is completed by bending the retaining plate 8 after insertion.

FIG. 8 shows the prior art embodiment of FIG. 7 as viewed from the front of the rotor disk 3.
Is inserted into the fitting groove 4 of the rotor disk 3,
It can be seen that the wing fixing part 5 is fixed by the retaining plate 7. The support part 6 of the blade fixing part 5 is sandwiched and fixed between the bottom of the blade root part 2 of the compressor blade 1 and the bottom of the rotor disk 3. In this conventional technique, the compressor blade 1 can be prevented from moving and dropping out of the fitting groove 4 of the rotor disk 3 as described above, but a gap 10 is formed between the blade root 2 and the fitting groove 4 after assembly. You. During operation of the gas turbine, there is a pressure difference between the front and rear of the compressor blades 1, so that air as a working fluid leaks through the gap 10, which causes a problem that the efficiency of the compressor is reduced.

FIG. 9 is a sectional view of the rotor disk 3 to which the compressor blade 1 is fixed by using the conventional technique. Compressor blade 1
It can be seen that the blade root portion 2 is fixed to the rotor disk 3 by the support portion 6 of the blade fixing component 5 and the retaining plates 7 and 8.

FIG. 1 shows an embodiment of the present invention designed to prevent leakage through the gap 10 shown in the prior art embodiment of FIG. The blade root portion 2 of the compressor blade 1 is inserted into the fitting groove 4 of the rotor disk 3 and is fixed by the blade fixing part 5 as in the prior art.
Since the dimension of 8 is a flat plate larger than the fitting groove 4, the retaining plates 7, 8 can entirely cover the gap 10 and prevent leakage of the working fluid through the gap 10 during operation of the gas turbine. It is possible to

A holding groove 1 for holding a support portion 6 of a blade fixing component 5 is provided at the bottom of the fitting groove 4 of the rotor disk 3.
1, the retaining portion 6 of the wing fixing component 5 is held slightly inward from the bottom of the fitting groove 4, so that the retaining plates 7, 8 cover the gap 10 entirely. Is possible.

FIG. 2 shows the embodiment of the present invention shown in FIG. Since the retaining plate 7 is larger than the fitting groove 4, the gap 1 between the fitting groove 4 and the blade root 2 is
It can be seen that 0 can be covered. Further, since the support portion 6 of the wing fixing component 5 is held by the holding groove 11 provided at the bottom of the fitting groove 4 of the rotor disk 3, the lower end 12 of the retaining plate 7 is located at a lower position than the bottom of the fitting groove 4. It is located on the inner peripheral side, and it is possible to cover the gap 10 entirely.

FIG. 3 shows another embodiment of the present invention. In the present embodiment, similarly to the embodiment of FIG. 1, the blade root 2 of the compressor blade 1 is inserted into the fitting groove 4 of the rotor disk 3 and fixed by the blade fixing part 5, but in this embodiment, the blade fixing is performed. The retaining plates 7 and 8 of the component 5 adopt a structure that covers only the gap 10 between the fitting groove 4 of the rotor disk 3 and the blade root 2.

FIG. 4 shows the embodiment of FIG. 3 as viewed from the front of the rotor disk.
0, the effect on leakage is the same as in the embodiment of FIGS. 1 and 2, but since the weight of the retaining plate 7 is reduced, the blade fixing part 5 It is possible to reduce the acting centrifugal force and improve the reliability.

FIG. 5 shows another embodiment of the present invention.
In this embodiment, the wing fixing part 5 is composed of the support part 6 and the retaining plate 7 provided at one end of the support part, and further requires another plate part 13. The plate part 13 has a hole 14 that can penetrate the support part 6 of the wing fixing part 5. The compressor blade 1 is fixed by disposing the blade fixing part 5 in the fitting groove 4 and inserting the blade root part 2, then disposing the plate part 12 in the support part 6 through the hole 13, and then setting the end of the support part 6. This is done by bending the part as shown.

FIG. 6 shows an embodiment having a different idea. In this embodiment, one end in the axial direction of the blade root portion 2 of the compressor blade 1 is provided with a plate-shaped portion 15 having a size larger than the fitting groove 4 in advance. For this reason, the compressor blade 1 is prevented from moving or dropping in the opposite direction to the rotor disk surface where the plate-shaped portion 15 exists. The movement or dropping of the plate-like portion 15 toward the rotor disk surface side is prevented by the wing fixing component 5 as in the embodiment of FIGS.

[0018]

According to the present invention, since the gap between the blade root of the compressor blade and the fitting groove of the rotor disk is covered by the blade fixing part or the plate provided at one end of the blade root, the gap can be reduced during operation of the gas turbine. The leakage of the working fluid through the gap can be suppressed to a minimum, and the efficiency of the compressor can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded view of a compressor blade fixing structure according to an embodiment of the present invention.

FIG. 2 is a view of a fixing structure of the compressor blade of FIG.

FIG. 3 is an exploded view of a compressor blade fixing structure according to an embodiment of the present invention.

FIG. 4 is a view of a compressor blade fixing structure according to an embodiment of the present invention as viewed from the front surface of a rotor disk.

FIG. 5 is an embodiment of a compressor blade fixing structure according to an embodiment of the present invention.

FIG. 6 is an exploded view of a fixed structure of the compressor blade.

FIG. 7 is an exploded view showing a compressor blade fixing structure shown as a conventional embodiment.

FIG. 8 is a view of a conventional example as viewed from the front surface of a rotor disk.

FIG. 9 is a sectional view of a rotor disk having a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor blade, 2 ... Blade root part, 3 ... Rotor disk, 4 ...
Fitting groove, 5: Blade fixing part, 6: Supporting part, 7, 8: Retaining plate, 9: Outer peripheral part, 10: Gap, 11: Holding groove, 12 ...
Lower end, 13: plate component, 14: hole, 15: plate-like portion.

Claims (1)

[Claims] A rotor disk having a fitting groove on the outer periphery;
In a compressor blade fixing structure including a compressor blade having a blade root portion that fits into the fitting groove and a blade fixing component, the blade fixing component is sandwiched between the compressor blade blade root bottom and the rotor disk fitting groove. A compressor blade comprising a support portion and plate portions formed at both ends or one end thereof, at least one of the plate portions having a shape covering a gap between a rotor disk fitting groove and a compressor blade root portion. Fixed structure.