JP3044911B2 - Gas turbine fastening device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastening device for a gas turbine.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view schematically showing an example of a conventional fastening device for a gas turbine. In the drawing, reference numeral 1 denotes a two-stage compressor, and 2 denotes a two-stage compressor connected to the rear of the compressor 1. Turbines 3, 4 are impellers of the compressor 1. Diffusers 7 and 8 having guide vanes 5 and 6 are formed between the impeller 3 and the impeller 4 and downstream of the impeller 4 so as to form a predetermined curve in a radial direction surrounding the outer periphery of each impeller 3 and 4. Behind the diffuser 8 is a combustor 9
And a combustion chamber 10 is provided in the combustor 9.

[0003] Reference numerals 11 and 12 denote rotor blades of the turbine 2, which are coaxially arranged with the impellers 3 and 4 in the axial extending direction.
The outer peripheral blades of the rotor blades 11 and 12 are surrounded by an annular combustion gas duct 13 extending from the combustion chamber 10 of the combustor 9. Fixed blades 15 and 16 are provided in the combustion gas duct 13 on the front side of each of the moving blades.

The impellers 3 and 4 of the compressor 1 and the moving blades 11 and 12 of the turbine 2 are connected to the impellers 3 and 4 respectively.
And a common tension bar 14 penetrating through the axis of each of the moving blades 11 and 12, between adjacent impellers 3 and 4, between each of the moving blades 11 and 12, and between the impeller 4 and the moving blade 11. Are accurately positioned and connected by the respective Carvic couplings 17 provided on the contact surfaces of the tension bars 14.
A nut 18 is screwed into the tip of the last stage disk (moving blade 12) side, and the impellers 3 and 4 are integrally fastened to the moving blades 11 and 12 by tightening the nut 18 with a predetermined torque. ing.

FIG. 4 shows the structure around the tightening portion by the nut 18 in detail. The structure is fitted to the tension bar 14 and is connected to the last disk (moving blade 12) of the turbine via the Carvic coupling 17. A disc holder 19 which can be connected to the tension bar 14 so that the inner ring 21 of the bearing 20 abuts on the end of the disc holder 19, and a nut which presses the inner ring 21 of the bearing 20. The screw 18 is screwed into the screw portion 22 of the tension bar 14 and tightened. 23 is a bearing support member in the figure,
Reference numeral 24 denotes an oil supply path, and reference numeral 25 denotes a bearing oil supply pipe.

Thus, each impeller 3 of the compressor 1
The rotor 4 is driven to rotate by the rotor blades 11 and 12 of the turbine 2 via the Carvic coupling 17, so that air is sucked into the compressor 1 and the impellers 3 and 4 increase the flow velocity of the air. The air is compressed by guiding the air to the diffusers 7 and 8 and converting the flow velocity of the air into pressure by the guide vanes 5 and 6 provided in the diffusers 7 and 8.

Further, the compressed air is introduced into a combustion chamber 10 of a combustor 9, mixed with fuel, and ignited to generate high-temperature and high-pressure combustion gas. The combustion gas is supplied to a turbine 2 by a combustion gas duct 13. The rotating blades 11 and 12 of the turbine 2 are driven to generate power.

[0008]

However, the above-mentioned gas turbine fastening device has a disk holder 19 which is pressed against the final stage disk (moving blade 12) of the turbine 2 via the Carbic coupling 17. Due to the configuration, there is a problem that the number of the formed Carbic couplings 17 that is difficult to process increases and the cost increases. Also, since the bearing 20 is directly assembled to the tension bar 14, an assembling operation for assembling with high precision is difficult. Also, the disk holder 19 is pressed by the nut 18 with the bearing 20 interposed therebetween. Therefore, there is a risk that rotation of the bearing 20 becomes unstable due to distortion or inclination of the bearing 20 due to strong tightening of the nut 18. In addition, the conventional nut 18 cannot take an excessively large cross-sectional area due to the convenience of pushing the inner ring 21 of the bearing 20 and the arrangement of the bearing oil supply pipe 25, and thus has a problem of tightening strength. I was

The present invention has been made in view of the above-mentioned circumstances, and has reduced the number of carbic couplings to be formed, thereby facilitating the assembly work of the bearing, improving the rotation stability of the bearing, and improving the tightening strength of the nut. It is an object of the present invention to provide a fastening device for a gas turbine.

[0010]

The present invention SUMMARY OF], in a gas turbine for fastening the blades of the impeller and the turbine of the compressor and fitted and connected through a curvic coupling together by tension bars, the curvic coupling
An extension extending toward the end of the tension bar is formed on the final stage disk of the turbine to be connected, and the extension has a thin wall.
It provided the small diameter portion is fitted arranged bearings, through the small-diameter portion by the tension bar end fastening nut screwed to the threaded portion
And a gas turbine fastening device characterized in that the final stage disk is tightened by connecting the impeller of the compressor and the rotor blade of the turbine via a Carbic coupling and integrally fastening them by a tension bar. In gas turbines, the connection
An extension extending in the direction of the end of the tension bar is formed on the last stage disk of the following turbine, and a threaded portion at the end of the tension bar has a thick portion at an end facing the extension and has a thick end. A stepped nut having a thin portion on its side is screwed in, a bearing is fitted and arranged on the thin portion of the stepped nut, and a stepped nut is provided.
To tighten the final stage disc through the extension
Those of the fastening device, a gas turbine, characterized in that the.

[0011]

According to the first aspect of the present invention, a tension bar is inserted through a plurality of compressor impellers and turbine blades, a bearing is fitted and disposed in a small diameter portion of the extension portion, and a tightening nut is connected to a screw portion of the tension bar. And a predetermined fastening force so as to press the overhang formed on the final stage disk so as to be integrated. Accordingly, the number of formed Carbic couplings is reduced, the work of assembling the bearing is facilitated, and a large axial force is not applied to the bearing inner ring, and the rotation of the bearing is stabilized.

According to the second aspect of the present invention, a tension bar is inserted through a plurality of compressor impellers and turbine blades,
The stepped nut is screwed into the threaded part of the tension bar and tightened with a predetermined fastening force so as to press the overhang formed on the final stage disk. Then, the bearing is fitted into the thin part of the stepped nut. Deploy. Therefore, the number of carbic couplings to be formed is reduced, the work of assembling the bearings becomes easy, the bearing inner ring is not subjected to a large axial force, the rotation of the bearing is stabilized, and the nut contact area is increased to tighten. Strength can also be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are sectional views showing an example of a fastening device for a gas turbine according to the first and second aspects of the present invention. FIG. 1 is an enlarged view of an extended portion for fitting a bearing, and FIG. An example using a stepped nut is shown. The other basic structure except for the fastening portion of the tension bar is substantially the same as that of the conventional gas turbine fastening device shown in FIG. 4, and the same components as those shown in FIG. The description is omitted, and a configuration specific to the present invention will be described below.

In FIG. 1 showing an embodiment of the first aspect of the present invention,
Impellers 3 and 4 of compressor 1 and rotor blade 1 of turbine 2
In the gas turbine in which the first and second gears 12 and 12 are fitted via a Carbic coupling 17 and fastened together by a tension bar 14, a final stage disk (the moving blade 12) of the turbine 2
Then, an extension 26 extending to the vicinity of the bearing 20 is integrally formed, and a small-diameter portion 33 is formed at the tip of the extension 26 so as to be thin and fitted with the bearing 20. A large tightening nut 34 exceeding the inner diameter of the inner ring 21 of the bearing 20 is screwed into the screw portion 22 of the tension bar 14.

The bearing 20 is fitted to the small diameter portion 33 of the extension portion 26, and the tightening nut 34 is screwed into the screw portion 22 of the tension bar 14 to be tightened. In the case shown in the figure, a short tension bar 14 ′ for fastening the impellers 3, 4 of the compressor 1 with the fastening nut 31 is provided, and another tension bar 14, which is connected to the tension bar 14 ′ via the screw portion 32. The blades 11 and 12 are tightened by the tension bar 14 having a configuration including "", and the diameter, length, and material required for each of the impellers 3 and 4 and each of the blades 11 and 12 are individually and It makes it possible to select the appropriate, economical and each tension bar 1
4 'and 14 "are shortened to facilitate processing and handling. In this case, similarly to FIGS. 3 and 4, one long tension bar 14 may be used for fastening. The good thing is, of course.

The blades 11 and 12 are attached to the tension bar 14.
When the bearing 20 is inserted and fastened integrally with the impellers 3 and 4, the bearing 20 is first press-fitted into the small-diameter portion 33 of the extension portion 26 and fitted by shrink fitting, and then the large-sized tightening nut 34 is tightened with the tension bar. 14 and the impellers 3 and 4 and the rotor blade 1 by tightening with a predetermined fastening force so as to press the extension portion 26 formed on the final stage disk (the rotor blade 12) by being screwed to the screw portion 22 of the rotor blade 1.
1 and 12 are integrated. Further, a bearing fixing screw 30 for restraining the bearing 20 is screwed into the screw portion 22 of the tension bar 14.

According to the above configuration, the conventional disk holder 19 (FIG. 4) is eliminated, and the final stage disk (the moving blade 1) is removed.
2) Extension portion 2 having small diameter portion 33 for fitting bearing 20
6 to form the extension 26 with a large-sized tightening nut 34.
, The number of the formed Carbic couplings 17 can be reduced.
0 is fitted and arranged on the outer periphery of the small diameter portion 33 of the extension portion 26, so that the assembling work of the bearing 20 is facilitated, the excessive pressing of the bearing 20 is prevented, and the rotation stability is improved. be able to.

In FIG. 2 showing an embodiment of the invention of claim 2,
Impellers 3 and 4 of compressor 1 and rotor blade 1 of turbine 2
In the gas turbine in which the first and second gears 12 and 12 are fitted via a Carbic coupling 17 and fastened together by a tension bar 14, a final stage disk (the moving blade 12) of the turbine 2
An extension 26 extending to the vicinity of the bearing 20 is formed integrally with the
The extension portion 2 is attached to the thread portion 22 of the tension bar 14.
6 has a thick portion 27 at the end portion and a thin portion 2 at the other end side.
The stepped nut 29 having 8 is screwed.

Further, the thin portion 28 of the stepped nut 29
The bearing 20 is fitted on the upper part by press-fitting, shrink fit, etc.
0 to the tension bar 1
4 is screwed into the screw portion 22.

The blades 11 and 12 are attached to the tension bar 14.
When the nut is inserted and fastened integrally with the impellers 3 and 4, the stepped nut 29 is screwed into the screw portion 22 of the tension bar 14 so as to press the extension 26 formed on the final stage disk (the moving blade 12). The impellers 3 and 4 and the moving blades 11 and 12 are integrated by tightening with a predetermined fastening force, and then the bearing 20 is fitted and arranged on the thin portion 28 of the stepped nut 29. Thereafter, a bearing fixing screw 30 is fastened to the screw portion 22 of the tension bar 14 to restrain the movement of the bearing 20.

According to the above configuration, the conventional disk holder 19 (FIG. 3) is eliminated, and the final stage disk (the moving blade 1) is removed.
Since the extension 26 is formed in 2) and the extension 26 is tightened by the stepped nut 29, the number of the formed carbic couplings 17 can be reduced. Since the bearing 20 is fitted around the outer periphery of the thin portion 28, it is possible to easily assemble the bearing 20 and prevent the bearing 20 from being excessively pressed, thereby improving the rotation stability. Further, the stepped nut 29 is provided inside the bearing 20 so as to have a long shape, so that tightening strength and screw coaxial accuracy can be improved.

The present invention is not limited only to the above-described embodiment. For example, the impeller of the compressor and the moving blades of the turbine are not limited to the number of stages shown in the drawings. It is needless to say that various changes can be made within.

[0024]

According to the first and second aspects of the present invention,
Since the conventional disk holder is eliminated and an extension is formed on the final stage disk, and the extension is tightened with the tightening nut or the step nut, the number of formed Carbic couplings can be reduced. Further, since the bearing is fitted and arranged on the outer periphery of the small-diameter portion of the extension portion or the outer periphery of the thin portion of the stepped nut, it is possible to easily assemble the bearing and prevent excessive pressing of the bearing. In the example using the stepped nut according to the second aspect of the present invention, it is possible to improve the stability of the rotation of the shaft. In addition, since the stepped nut is provided inside the bearing and has a long shape, the tightening strength and the coaxial accuracy are improved. Various excellent effects can be achieved, such as improvement in the quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of the first invention.

FIG. 2 is a sectional view showing an embodiment of the invention of claim 2;

FIG. 3 is a cross-sectional view schematically illustrating an example of a conventional gas turbine fastening device.

FIG. 4 is a cross-sectional view showing a configuration around a fastening portion of FIG. 3 in detail.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Turbine 3 Impeller 4 Impeller 11 Rotor blade 12 Rotor blade (final stage disk) 14 Tension bar 17 Carbic coupling 20 Bearing 22 Screw part 26 Extension part 27 Thick part 28 Thin part 29 Step nut 33 Small diameter part 34 Tightening nut

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F01D 25/00 F01D 25/16 F02C 7/20

Claims (2)

(57) [Claims] In a gas turbine in which an impeller of a compressor and a rotor blade of a turbine are fitted and connected via a Carbic coupling and integrally fastened by a tension bar, the gas turbine is connected to a final stage disk of the turbine connected by the Carvic coupling. forms an extension portion extending endwise of the tension bar, a bearing is provided small-diameter portion of the thin-walled said extension portion
The final stage disk is tightened through the small-diameter portion with a tightening nut screwed into the end thread portion of the tension bar.
A fastening device for a gas turbine, wherein the fastening device is attached . 2. A gas turbine fastening the blades of the impeller and the turbine of the compressor together by fitting connected tension bar through a curvic coupling, the final stage disc of the turbine to be connected by curvic coupling A step having an extension extending in the direction of the end of the tension bar, and having a threaded portion at the end of the tension bar, a thick portion at the end facing the extension, and a thin portion at the other end. The stepped nut is screwed in, the bearing is fitted and arranged on the thin portion of the stepped nut, and the stepped nut is extended through the extension.
A gas turbine fastening device, wherein a final stage disk is fastened.