JPH07324632A - Cooling air sealing device for gas turbine moving blade - Google Patents

Abstract

PURPOSE:To restrain engine performance from being degraded by preventing the cooling air at the blade root part of a gas turbine moving blade from leaking. CONSTITUTION:By elastically-deforming the cylindrical part (c) of a spacer 3 and a disc part (b) by means of centrifugal force which works upon a counter weight part (a), a sealing part 8 is pressed against the root part of a moving blade 1 to secure and support the moving blade 1 onto a disc 2 and seal cooling air of the moving blade.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD This invention relates to the support and sealing of gas turbine blades.

[0002]

2. Description of the Related Art FIG. 4 is a longitudinal sectional view showing an example of a conventional gas turbine rotor blade supporting method. As shown in this figure, conventionally, the seal ring (6) is fixed to the disc (2) with bolts (5). (1) is a moving blade.

[0003]

In the conventional method for supporting a gas turbine moving blade, since the seal ring (6) is fixed to the disk (2) by the bolt (5), the number of parts is large and the assembly is difficult. It was complicated. Further, the cooling air for the moving blade may leak due to the deformation of the seal ring (6). If cooling air leaks, the performance of the engine will deteriorate (fuel consumption will worsen), so measures to reduce air leakage are indispensable for improving engine performance.

[0004]

In order to solve the above-mentioned conventional problems, the present inventor has proposed a plurality of rotating disks fixed to each other by bolts and having a plurality of moving blades implanted in the outer peripheral portion thereof, and those rotating disks. A thin-plate cylindrical seal spacer that is shrink-fitted closer to the rotation axis than the implant portion between the disks, and a blade root part of the moving blade that is fixed to one end of the seal spacer via a thin-plate disk portion. The present invention proposes a cooling air sealing device for a gas turbine rotor blade, which is provided with a counterweight that contacts one tooth pressure surface.

[0005]

Since the present invention is configured as described above, when the gas turbine rotates, one end portion of the thin-plate cylindrical seal spacer that is shrink-fitted closer to the rotation axis than the moving blade implanting portion between the rotating disks. The thin plate cylindrical seal spacer and the disk portion are elastically deformed by the centrifugal force acting on the counter weight fixedly attached to the counter blade through the thin disk portion, and the counter weight is the blade root first tooth pressure of the moving blade. It is strongly pressed against the surface, effectively preventing the leakage of cooling air.

[0006]

1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a detailed view of another sectional view taken along the line II in FIG. The moving blade (1) in the figure is inserted into the blade groove of the disk (2) from the front (left side in the figure), and the axial position is determined by the stopper (9). The spacer (3) is shrink-fitted to the disc (2) at the fitting portion (7) to determine the radial position. The axial position of the spacer (3) is determined by bringing the spacer (3) and the moving blade (1) into contact with each other at the seal portion (8). A space is provided between the adjacent disk (4) and the spacer (3) in both the radial direction and the axial direction so that they can be assembled. Since the disk (2) and the disk (4) are fixed to each other by the bolts (5), the spacer (3) can support the moving blade (1) without coming off.

The disk portion (b) and the cylindrical portion (c) of the spacer (3) are thin flexible plates, and as shown by the solid line in FIG. 3, the counterweight portion (a) is centrifuged. The bending moment caused by the force elastically deforms, so that the seal portion (8) is pressed toward the moving blade (1). By adjusting the shape of the counterweight portion (a), the amount of deflection of the disk portion (b) and the cylindrical portion (c) can be controlled, so that the gap is reduced and the rotor blade (1) cooling air leaks. Can be reduced.

In this embodiment, INCO718, which is one of the heat-resistant alloys, is used as the material of the spacer (3). This is because the temperature at the place of use is as high as about 500 ° C,
This is because this material, which has excellent high temperature strength, is suitable.

The spacer (3) and the disc (2) are fitted to each other in order to align the cores of the spacer and the disc. The fitting portion is provided with notches at about eight places on the circumference in order to guide cooling air for the blade root. Since the metal temperature is different between the spacer (3) and the disc (2) in the axial direction, the spacer (3) is provided in order to prevent the spacer (3) from being stretched by thermal expansion and causing unreasonable interference with the disc (2). It is a thing.

Adjacent disk (4) and spacer (3)
At the time of assembling, the fitting portion with and is a loose fit so that the disk spacer can be assembled. During operation, the spacer (3) extends more radially than the disc (4), so that the fitting portion becomes tight and the core is retained.

[0011]

As described above in detail, in the cooling air sealing device for a gas turbine rotor blade of the present invention, the elastic deformation seal utilizing centrifugal force can effectively reduce the leakage of cooling air.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a detailed view of another cross section taken along the line II in FIG.

FIG. 3 is a diagram showing a state of elastic deformation in the above embodiment.

FIG. 4 is a longitudinal sectional view showing an example of a conventional gas turbine blade supporting method.

[Explanation of symbols]

 (1) Blade (2) Disk (3) Spacer (a) Counterweight part (b) Disk part (c) Cylindrical part (4) Disk (5) Bolt (6) Seal ring (7) Fitting part (8) ) Seal part (9) Stopper

Claims (1)

[Claims] 1. A plurality of rotating disks fixed to each other by bolts and having a plurality of moving blades implanted in the outer peripheral portion thereof, and a thin plate shrink-fitted closer to the rotation axis than the implanted portions between the rotating disks. A gas comprising: a cylindrical seal spacer; and a counterweight fixed to one end of the seal spacer via a thin plate-shaped disc portion and in contact with the blade root first tooth pressure surface of the moving blade. Cooling air sealing device for turbine blades.