JP2005042616A - Shroud segment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a shroud segment 7 to be sufficiently cooled by cooling air CA while maintaining suitably a cooling efficiency of the shroud segment 7 and to lengthen the lifetime of the shroud segment 7. <P>SOLUTION: The shroud segment includes many cooling holes 27 formed in a segment body 9 in which the cooling air CA flows, and many spot facing holes 29 formed on the inner surface 9a of the segment body 9 to surround outlets of the corresponding cooling holes 27 and constituted in long hole shapes which become long along an arc direction of the segment body 9 or constituted in round hole shapes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to the technical field of gas turbine engines such as aircraft engines, and more particularly to a shroud segment of a turbine shroud used for a turbine in a gas turbine engine.

  Turbine shrouds are used in turbines in gas turbine engines, such as aircraft engines, to efficiently extract work, and this turbine shroud is placed in a turbine case and is properly aligned with the tip of a turbine blade during engine operation. Is to maintain a good clearance. In order to prevent excessive thermal stress from being generated in the turbine shroud during engine operation, the turbine shroud is usually divided into a plurality of shroud segments, and the turbine shroud is affected by the influence of combustion gas. In order to suppress the temperature rise of the turbine shroud, each shroud segment is configured to be cooled by cooling air.

  The configuration of the general shroud segment will be specifically described as follows. That is, the shroud segment includes a segment main body held by the turbine case, and the inner surface of the segment main body is configured to allow rubbing with the tip of the turbine rotor blade. In addition, a cooling recess to which cooling air is supplied is formed on the outer surface of the segment body. Further, the segment body is formed with a number of cooling holes through which cooling air flows, and each cooling hole penetrates the bottom surface side of the cooling recess and the inner surface side of the segment body so as to communicate with each other. It is configured.

  Usually, a part of the compressed air compressed by the compressor in the gas turbine engine is used as cooling air.

  Therefore, when the turbine shroud (the plurality of shroud segments) maintains an appropriate clearance from the tip of the turbine blade while the engine is operating, the turbine can efficiently extract work. In addition, when cooling air is supplied to the cooling recess, the cooling air flows through the plurality of cooling holes, and the shroud segment can be cooled.

In addition, there exists a thing shown to patent document 1 as a prior art relevant to this invention.
JP 2000-291410 A

  By the way, if the exit side of the cooling hole is scraped by rubbing (rubbing) the inner surface of the segment body and the tip of the turbine rotor blade during engine operation, shavings (in addition to shavings on the inner surface of the segment body) In addition, the tip of the turbine rotor blade (including cutting chips) may remain in the cooling hole and cause the cooling hole to be blocked. Therefore, when the number of cooling holes in the shroud segment increases in the number of cooling holes in the closed state, the cooling efficiency of the shroud segment (the cooling efficiency of the turbine shroud) decreases, and the shroud segment ( There is a problem that the turbine shroud) cannot be sufficiently cooled, and the life of the shroud segment (the turbine shroud) is shortened.

In the invention according to claim 1, in the shroud segment formed by dividing the turbine shroud disposed in the turbine case and maintaining an appropriate clearance from the tip of the turbine rotor blade during engine operation,
An arcuate segment main body configured to allow rubbing of the inner surface with the tip of the turbine rotor blade, and held by the turbine case;
A plurality of cooling holes formed in the segment body, each configured to penetrate the outer surface side and the inner surface side of the segment body, and through which cooling air flows;
And a number of counterbore holes formed so as to surround the outlet of the cooling hole corresponding to the inner surface of the segment body.

  According to the invention specific matter of the first aspect, since a number of the counterbore holes are formed on the inner surface of the segment body so as to surround the outlets of the corresponding cooling holes, the outlet side of each cooling hole is defined. It can be made to immerse with respect to the inner surface of the said segment main body. Thereby, as long as the counterbore remains, even if the inner surface of the segment body is scraped by rubbing (rubbing) with the inner surface of the segment body and the tip of the turbine rotor blade during engine operation, The exit side of the cooling hole is not shaved.

  In addition to the above-described operation, the turbine can efficiently extract work by maintaining an appropriate clearance between the turbine shroud (the plurality of shroud segments) and the tip of the turbine rotor blade during engine operation. Further, when the cooling air is supplied to the outer surface side of the segment main body, the cooling air flows through the numerous cooling holes, and the shroud segment can be cooled.

  In the invention according to claim 2, in addition to the specific matters of the invention according to claim 1, each counterbore is configured in a long hole shape that becomes longer along the arc direction of the segment body. It is characterized by being.

  In the invention according to claim 2, in addition to the action according to the invention specific matter according to claim 1, each counterbore has an elongated hole shape that is elongated along the arc direction of the segment body. Therefore, even if rubbing occurs between the inner surface of the segment main body and the tip of the turbine rotor blade during engine operation, the cooling hole in the inner surface of the segment main body remains as long as the counterbore remains. The peripheral edge of is not cut away.

  The invention according to claim 3 is characterized in that, in addition to the invention specific matter according to claim 1, each counterbore is configured in a round hole shape.

  According to the invention specific matter of claim 3, the same effect as the effect of the invention specific matter of claim 1 is achieved.

  According to a fourth aspect of the present invention, in addition to the invention specific matter according to any one of the first to third aspects, the counterbore depth is determined during engine operation. When it is assumed that the inner surface of the segment body is scraped by rubbing with the tip of the turbine rotor blade, the segment body is configured to be deeper than the assumed scraping amount of the inner surface of the segment body. .

  According to the invention specific matter of claim 4, in addition to the action of the invention specific matter of any one of claims 1 to 3, the depth of the counterbore is the assumed shaving. Even if the inner surface of the segment main body is scraped by rubbing (rubbing) with the inner surface of the segment main body and the tip of the turbine rotor blade during engine operation, The counterbore does not disappear, in other words, the outlet side of the cooling hole is not shaved.

  In the invention according to claim 5, in addition to the invention specific matter according to any one of claims 1 to 4, it is formed on the outer surface of the segment main body, and the bottom side is many. The cooling hole is communicated with the inner surface side of the segment body through the cooling hole, and is provided with a cooling recess to which cooling air is supplied.

  According to the invention specific matter of claim 5, when cooling air is supplied to the cooling recess in addition to the action of the invention specific matter of any one of claims 1 to 4. The cooling air flows from the cooling recess to the cooling holes.

  In the invention according to claim 6, in addition to the specific matters of the invention according to claim 5, it is formed in the segment body and penetrates the inner wall of the cooling recess and the outer wall of the segment body so as to communicate with each other. Each of which has a plurality of auxiliary cooling holes through which cooling air flows.

  According to the invention specific matter of claim 6, in addition to the action of the invention specific matter of claim 5, when cooling air is supplied to the cooling recess, in addition to the many cooling holes, many Since cooling air flows through the auxiliary cooling holes, the cooling efficiency of the shroud segment (the turbine shroud) can be increased.

  According to the first aspect of the present invention, even if the inner surface of the segment main body is scraped by rubbing (rubbing) between the inner surface of the segment main body and the tip of the turbine rotor blade during engine operation, the counterbore As long as the hole remains, the exit side of the cooling hole is not shaved. Therefore, shavings are less likely to enter the cooling hole, and the cooling hole can be prevented from being blocked by the remaining shavings. Therefore, while maintaining the cooling efficiency of the shroud segment (cooling efficiency of the turbine shroud) appropriately, the shroud segment (the turbine shroud) can be sufficiently cooled by the cooling air, and the life of the shroud segment (the above-mentioned The life of the turbine shroud can be extended.

  According to the second aspect of the present invention, as long as the counterbore remains, even if rubbing occurs between the inner surface of the segment main body and the tip of the turbine rotor blade during engine operation, Since the peripheral edge of the cooling hole on the surface is not cut, the cooling hole is hardly blocked by the residue of shavings, and the effect of the invention according to claim 1 can be further improved.

  In invention of Claim 3, there exists an effect similar to the effect of invention of Claim 1.

  According to the invention described in claim 4, even if the inner surface of the segment body is scraped by rubbing (rubbing) between the inner surface of the segment body and the tip of the turbine rotor blade during engine operation, the cooling hole Therefore, the effect of the invention according to claim 1 or 2 is further stabilized.

  According to the invention described in claim 5, the same effect as the effect described in any one of claims 1 to 4 can be obtained.

  According to the sixth aspect of the invention, in addition to the effects of the fifth aspect of the invention, the cooling efficiency of the shroud segment (the cooling efficiency of the turbine shroud) can be increased. The service life (the service life of the turbine shroud) can be further increased.

  The best mode of the present invention will be described with reference to FIGS.

  Here, FIG. 1 is a partial cross-sectional view of a high-pressure turbine in a gas turbine engine according to the best mode of the present invention, and FIG. 2 is a cross-sectional view taken along line II in FIG. 3 is a plan view of a shroud segment according to the best mode of the present invention, FIG. 4 is an enlarged cross-sectional view of a portion II in FIG. 2, and FIG. 5 shows a counterbore hole according to another embodiment. It is an expanded sectional view. Further, “front and back” refers to the front and back sides in FIG. 1 and FIG. The orientation of each drawing will be described based on the state at the time of publication of the patent publication.

  As shown in FIG. 1, a turbine shroud 1 according to the best mode of the present invention is used for a high pressure turbine in a gas turbine engine such as an aircraft engine, and is disposed in a high pressure turbine case 3 and the engine is operating. In addition, an appropriate clearance from the tip of the turbine rotor blade 5 is maintained. The turbine shroud 1 is divided into a plurality of shroud segments (only one is shown in FIG. 1) 7, and the specific configuration of the shroud segment 7 is as follows.

  As shown in FIGS. 1 to 3, the shroud segment 7 according to the best mode of the present invention includes an arc-shaped segment body 9 held by the high-pressure turbine case 3, and an inner surface 9 a of the segment body 9. Is configured to allow rubbing with the tip of the turbine rotor blade 5. In addition, a segment insert 15 that can be fitted into the circumferential groove 13 of the front case hook 11 in the high-pressure turbine case 3 is integrally formed at the front end of the segment body 9. The U-shaped C-shaped clip 17 forms a segment hook 21 that is held by the rear case hook 19 in the high-pressure turbine case 3. Here, the segment insert 15 is fitted into the circumferential groove 13 of the front case hook 11, and the segment hook 21 is held by the rear case hook 19, whereby the segment body 9 is held by the high-pressure turbine case 3. .

  On the outer surface 9b of the segment body 9, a cooling recess 23 to which cooling air CA is supplied is formed. The cooling air CA is air compressed by a compressor (not shown), and is introduced between the high-pressure turbine case 3 and the turbine shroud 1 through the introduction hole 25 of the front case hook 11. The segment body 9 is formed with a number of cooling holes 27 through which the cooling air CA flows. Each cooling hole 27 has a bottom surface 23a side (the outer surface 9b side of the segment body 9) of the cooling recess 23 and the segment body. 9 are respectively formed so as to communicate with the inner surface 9a side.

  Furthermore, a number of counterbore holes 29 are formed on the inner surface 9 a of the segment body 9 so as to surround the outlets of the corresponding cooling holes 27. Here, each counterbore 29 is configured in an elongated hole shape that is elongated along the arc direction of the segment body 9 (the left-right direction in FIGS. 2 and 4), as shown in FIGS. 2 and 4. Accordingly, the depth of the counterbore 29 is determined so that the inner surface 9a of the segment body 9 is assumed to be scraped by rubbing with the tip of the turbine rotor blade 5 during engine operation. It is configured to be deeper than the assumed scraping amount m of 9a.

  Each counterbore 29 is formed in a round hole shape as shown in FIG. 5 instead of being formed in a long hole shape that is elongated along the arc direction of the segment body 9 (see FIG. 4). It can be configured.

  As shown in FIGS. 2 to 4, one side of the segment body 9 (left side in FIGS. 2 and 4, upper side in FIG. 3) and other side (right side in FIGS. 2 and 4, right side in FIG. 3) A plurality of auxiliary cooling holes 31 are formed in the lower side portion, and each auxiliary cooling hole 31 is configured to penetrate the inner wall 23b of the cooling recess 23 and the outer wall 9c of the segment body 9 so as to communicate with each other. ing. Further, a seal groove 35 into which a side portion of the air seal 33 can be fitted is formed in both outer walls 9c of the segment body 9. The air seal 33 prevents the cooling air CA (see FIG. 1) from leaking from between the adjacent shroud segments 7 to the mainstream side (lower side in FIGS. 2 and 4).

  Next, the operation of the best mode of the present invention will be described.

  Since a number of counterbore holes 29 are formed in the inner surface 9a of the segment body 9 so as to surround the outlets of the corresponding cooling holes 27, the outlet side of each cooling hole 27 is connected to the inner surface 9a of the segment body 9. I can immerse myself. Further, since the depth of the counterbore hole 29 is configured to be deeper than the assumed cutting amount m, the segment main body 9b is rubbed with the inner surface 9a of the segment main body 9 and the tip of the turbine rotor blade 5 while the engine is running. However, the counterbore 29 does not disappear even if the inner surface is cut. Thereby, even if the inner surface 9a of the segment main body 9 is scraped by rubbing the inner surface 9a of the segment main body 9 and the tip of the turbine rotor blade 5 during engine operation, the outlet side of the cooling hole 27 is not scraped.

  In particular, when each counterbore 29 is formed in an elongated hole shape that is elongated along the arc direction of the segment body 9 (see FIG. 4), the inner surface of the segment body 9 during engine operation Even if the rubbing between 9a and the tip of the turbine rotor blade 5 occurs, the peripheral edge portion of the cooling hole 27 on the inner surface 9a of the segment body 9 is not scraped.

  In addition to the above-described operation, the high pressure turbine can efficiently extract work by maintaining an appropriate clearance between the turbine shroud 1 (the plurality of shroud segments 7) and the tip of the turbine rotor blade 5 while the engine is operating. . Further, when the cooling air CA is supplied to the cooling recess 23, the cooling air CA flows from the cooling recess 23 to the multiple cooling holes 27 and the plurality of auxiliary cooling holes 31, so that the shroud segment 7 can be cooled. Here, when the cooling air CA is supplied to the cooling recess 23, the cooling air CA flows to the plurality of auxiliary cooling holes 31 in addition to the large number of cooling holes 27, so that the cooling efficiency of the shroud segment 7 (the turbine shroud 1 (Cooling efficiency) can be increased.

  As described above, according to the best mode of the present invention, even if the inner surface 9a of the segment body 9 is scraped by rubbing between the inner surface 9a of the segment body 9 and the tip of the turbine rotor blade 5 during engine operation, Since the exit side of the hole 27 is not shaved, the shavings are less likely to enter the cooling hole 27, and the blockage of the cooling hole 27 due to the remaining shavings can be sufficiently and stably suppressed. Therefore, the shroud segment 7 (turbine shroud 1) can be sufficiently cooled by the cooling air CA while properly maintaining the cooling efficiency of the shroud segment 7 (cooling efficiency of the turbine shroud 1), and the life of the shroud segment 7 ( The life of the turbine shroud 1 can be extended.

  In particular, when each counterbore 29 is formed in an elongated hole shape that is elongated along the arc direction of the segment main body 9, the inner surface 9 a of the segment main body 9 and the turbine rotor blade 5 during engine operation. Even if rubbing with the tip of the segment occurs, the peripheral edge portion of the cooling hole 27 in the inner surface 9a of the segment body 9 is not scraped, so that the cooling hole 27 is hardly blocked due to residual shavings. The effect is further improved.

  The present invention is not limited to the above description of the best mode, and can be implemented in various other modes by appropriate modifications.

1 is a partial cross-sectional view of a high-pressure turbine in a gas turbine engine according to the best mode of the present invention. It is sectional drawing along the II line in FIG. It is a top view of the shroud segment concerning the best form of this invention. It is an expanded sectional view of the II section in FIG. It is an expanded sectional view showing a counterbore hole of another mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turbine shroud 3 High pressure turbine case 5 Turbine rotor blade 7 Shroud segment 9 Segment main body 23 Cooling hollow 27 Cooling hole 29 Counterbore

Claims (6)

In a shroud segment formed by dividing a turbine shroud disposed in a turbine case and maintaining an appropriate clearance from the tip of a turbine blade during engine operation,
An arcuate segment main body configured to allow rubbing of the inner surface with the tip of the turbine rotor blade, and held by the turbine case;
A plurality of cooling holes formed in the segment body, each configured to penetrate the outer surface side and the inner surface side of the segment body, and through which cooling air flows;
A shroud segment comprising a number of counterbore holes formed so as to surround an outlet of the cooling hole corresponding to an inner surface of the segment body. 2. The shroud segment according to claim 1, wherein each counterbore is configured in an elongated hole shape that is elongated along an arc direction of the segment main body. The shroud segment according to claim 1, wherein each counterbore is configured in a round hole shape. The depth of the counterbore is based on an assumed amount of scraping of the inner surface of the segment body, assuming that the inner surface of the segment body is scraped by rubbing with the tip of the turbine rotor blade during engine operation. The shroud segment according to any one of claims 1 to 3, wherein the shroud segment is configured to be deep. A cooling recess formed on the outer surface of the segment body, the bottom surface side being connected to the inner surface side of the segment body by a plurality of the cooling holes, and supplied with cooling air. The shroud segment according to any one of claims 1 to 4. A plurality of auxiliary cooling holes formed in the segment main body and configured to pass through the inner wall of the cooling depression and the outer wall of the segment main body, and through which cooling air flows. The shroud segment of claim 5.

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