JP2000345997A - Variable stationary vane mechanism for axial flow compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable stationary vane mechanism for an axial flow compressor capable of controlling a gap-flow flowing from a pressure surface to a suction surface through the gaps between end parts of a variable stationary vane for reducing the pressure loss in vicinity of a passage wall to improve the efficiency of a compressor. SOLUTION: Stationary vanes 1 constituting a cascade of blades are supported being allowed to swing around a shaft core 1a extended in the radial direction, and flexible sealing members 10 are attached on the end parts of the stationary vanes. The sealing members are heat-resistant rubber members whose end parts are thicker than those of tip parts thereof, and one ends 10a are fixed to the end parts of the vanes and the other ends 10b slide on the wall surface 6 supporting the stationary vanes while contacting with it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a variable vane mechanism for an axial compressor.

[0002]

2. Description of the Related Art In an axial compressor such as a jet engine,
It is necessary to largely swing the direction of the stationary blade at the time of idling or high rotation with respect to the direction of the stationary blade at the rated rotation speed in order to maintain and improve the performance. The swing angle reaches, for example, 60 to 70 ° at the maximum. Therefore, in the axial-flow compressor, a variable static vane mechanism (Variable Static Vane: VSV) schematically shown in FIG. 2 is used to secure operation stability in a wide operation range from low-speed rotation to high-speed rotation.

[0003]

Generally, the flow path of a compressor gradually narrows from an upstream side to a downstream side in accordance with the compression of gas (air). In such a flow path, the variable vane can rotate around the support axis without contacting the flow path wall,
A gap is provided at both ends of the variable stationary blade. This gap is
The minimum is about 0.2 mm, and when it is large, it is about 1 mm or more.

FIG. 3 schematically shows a main flow 2 of the variable stationary blade 1 and a gap flow 3 in a blade tip clearance. In this figure, (A)
Is a cascade diagram of the variable stator vane 1, (B) is a view taken along the line AA,
FIG. 3C is a pressure loss characteristic diagram. As shown in FIGS. 3A and 3B, when there is a blade tip clearance, the pressure difference between the pressure side (ventral side) and the suction side (back side) existing near the wing surface causes the wing from the ventral side of the wing. A gap flow 3 flowing to the side is generated. Since this gap flow 3 flows in a direction substantially orthogonal to the main flow 2 between the blades, as shown in FIG. 3 (C), the pressure loss near the flow path wall rapidly increases, and the efficiency decreases. Note that in FIG.
4 is a moving blade.

The present invention has been made to solve such a problem. That is, an object of the present invention is to prevent a gap flow flowing from the pressure side to the suction side through a gap generated at the end of the variable vane, thereby reducing the pressure loss near the flow path wall and improving the efficiency of the compressor. It is an object of the present invention to provide a variable vane mechanism of an axial flow compressor which can improve the pressure.

[0006]

According to the present invention, each vane (1) constituting a cascade has an axial center (1a) extending in a radial direction.
, And one end (10a) is fixed to the blade tip of each stationary blade, and the other end (10b) slides while contacting the wall surface (6) supporting the stationary blade. A variable vane mechanism for an axial flow compressor, comprising a seal member (10) is provided.

According to the configuration of the present invention, the other end (10b) of the flexible seal member (10) comes into contact with the wall surface (6) even if the gap at both ends changes due to the swing of the variable stator blade. Since the sliding is performed while the swing angle is in the fully open state, for example, there is no deformation and the wing tip gap is filled, and when the swing angle is in the fully closed state, the wing tip gap can be deformed and filled. Therefore, the blade tip clearance can be substantially eliminated in the entire operation range from low-speed rotation to high-speed rotation, clearance flow can be eliminated, and pressure loss on the side wall can be reduced.

According to a preferred embodiment of the present invention, the flexible seal member (10) has a heat-resistant rubber having a thick end portion and a thin tip portion so as to enhance the ability to follow the wall surface (6). It is a member.

With this configuration, the tip of the flexible seal member (10) is flexibly deformed like a wiper rubber of a car,
Since the end is firmly fixed to the variable vane, the wall (6)
Follow-up performance can be improved. Further, by using the heat-resistant rubber member, it is possible to withstand the operating temperature (100 to 200 ° C.) on the front stage side of the fan or the compressor in which the variable stationary blade mechanism of the axial flow compressor is generally provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted. FIG. 1 is a schematic diagram of a variable vane mechanism of the axial compressor of the present invention. In this figure, (A) is a cascade diagram of the axial compressor, (B) is a partial cross-sectional view along the line AA, and (C) is a characteristic diagram thereof.

As shown in FIG. 1A, the variable vane mechanism of the axial compressor of the present invention is installed between the outer flow path wall 5a and the inner flow path wall 5b of the axial flow compressor. The variable stationary blade 1 is supported by two support shafts 1a fixed to both end surfaces, and swings about its axis by a variable mechanism (not shown). A moving blade 4 is disposed downstream of the variable stationary blade 1. In addition, as illustrated in FIG. 2, the variable stationary blade 1 may be supported by one support shaft. Further, the variable vane mechanism of the axial flow compressor of the present invention is preferably provided at a stage preceding the fan or the compressor.

As shown in FIGS. 1A and 1B, the variable vane mechanism of the axial flow compressor according to the present invention includes a flexible seal member 10 at the tip of each vane 1. This sealing member 10
Is thicker at the end and thinner at the tip so as to enhance the followability of the outer flow path wall 5a and the inner flow path wall 5b to the wall surface 6. The member 10 is made of a well-known heat-resistant rubber (for example, silicon rubber) that withstands an operating temperature (for example, 100 to 200 ° C.) on the front side of the fan or the compressor.

As shown in FIG. 1B, one end 10a (end) of the seal member 10 is fixed to the tip of the vane 1, and the other end 10b (tip) supports the vane. It slides while contacting the wall surface 6. The fixing to the wing tip is performed, for example, by bonding or mechanically assembling and mounting. Further, as shown in FIG. 1A, when the support shaft 1a is relatively thick, one is provided before and after the support shaft 1a on both the inner wall and the outer wall.
It is preferable that the seal member 10 is divided and attached to individual parts. Therefore, four such components are mounted on one variable stationary blade 1.

As the heat-resistant rubber, a flexible rubber such as a wiper rubber of a car is used. Therefore, this part fixed to the wing tip is flexible and deformable. For example, when the swing angle of the variable vane 1 is fully open, there is no deformation to fill the wing tip gap, and when the angle is fully closed, it deforms. To fill the wing tip gap.

According to the configuration of the present invention described above, the variable vane 1
Even if the gap between the two ends changes due to the swinging, the other end 10 b of the flexible seal member 10 slides while contacting the wall surface 6. Can always be filled. Therefore, the blade tip clearance can be substantially eliminated in the entire operation range from low-speed rotation to high-speed rotation, the clearance flow can be eliminated, and the pressure loss in the side wall can be reduced as shown in FIG.

It should be noted that the present invention is not limited to the above-described embodiments and examples, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0017]

As described above, the variable vane mechanism of the axial flow compressor according to the present invention can prevent the gap flow from the pressure side to the suction side through the gap generated at the end of the variable vane. Thereby, there is an excellent effect that pressure loss near the flow path wall can be reduced and the efficiency of the compressor can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a variable stationary blade mechanism of an axial flow compressor according to the present invention.

FIG. 2 is a configuration diagram of a variable vane mechanism of a conventional axial flow compressor.

FIG. 3 is a schematic diagram of a gap flow in a conventional variable vane mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Variable stationary blade 2 Main flow 3 Gap flow 4 Moving blade 5a Outer channel wall 5b Inner channel wall 6 Wall surface 10 Flexible seal member 10a One end 10b Other end

Claims (2)

[Claims] 1. A stationary blade (1) constituting a cascade is supported swingably around an axial center (1a) extending in a radial direction, and one end (10a) is fixed to a blade end of each stationary blade. And the other end (10
b) comprises a flexible seal member (10) that slides while contacting a wall surface (6) supporting the vane, wherein the variable vane mechanism of the axial flow compressor is provided. 2. The flexible seal member (10) is a heat-resistant rubber member having a thick end portion and a thin tip portion so as to enhance the followability to the wall surface (6). The variable vane mechanism of the axial flow compressor according to claim 1.