JPH0658171A - Seal ring - Google Patents

Abstract

PURPOSE:To ensure excellent sealing ability over a long period of time by a method wherein a seal ring located in an annular space between a duct made of ceramic and a duct maple of a metal comprises a sheet made of a metal and a ring made of ceramic, and the ring made of ceramic is contained in the annular recessed part of the ring of a metal. CONSTITUTION:In a monoaxial gas turbine engine, combustion gas from a combustor is guided to a turbine rotor through an adapter 13 made of a metal and a scroll body 14 made of ceramic. The adapter 13 and the scroll body 14 respectively forming a duct are interconnected in a way that a stepped part 13a formed at the adapter 13 is inserted in the stepped part 14a of the scroll body 14. An annular space 20 formed between the two stepped parts 13a and 14a is sealed by means of a seal ring 30. In this case, the seal ring 30 is arranged on the inner side and comprises a ring 31 made of a metal in the outer surface of which an annular recessed part 31b is formed and an outer ring 32 made of ceramic loosely fitted in the recessed part 31b. Excellent sealing ability is ensured by preventing the occurrence of thermal deformation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention seals an annular space formed at a connecting portion between a duct made of ceramics because it becomes extremely high in temperature and a metal duct which does not become so high in temperature. The seal ring for doing.

[0002]

2. Description of the Related Art The connection between two such ducts is made, for example, in a gas turbine engine. A gas turbine engine guides combustion gas generated by a combustor to a turbine rotor through a scroll duct,
This gas drives the turbine rotor to obtain power.

In order to drive the turbine rotor efficiently, the combustion in the combustor is not perfect, but the combustion gas in the middle of this combustion is gradually combusted in the scroll duct and completely combusted immediately before the turbine rotor. In this way, the thermal efficiency is improved. recent years,
As described in Japanese Patent Application No. 3-82253, the scroll duct is made of ceramic having excellent heat resistance, so that the combustion gas temperature immediately before the turbine rotor can be further increased, and higher power can be obtained. A gas turbine engine capable of being proposed has been proposed.

In such a gas turbine engine, since the combustor is continuously supplied with low-temperature compressed air from the compressor and the combustion is not perfect, the combustor does not reach such a high temperature. Similarly, it is made of metal in consideration of cost.

[0005]

In the above-mentioned prior art, a seal ring is provided at the connecting portion between the metal combustor outlet and the ceramic scroll duct. This seal ring is in contact with both, and if a metal seal ring is used, the high heat of the scroll duct causes fatigue and it becomes impossible to seal, so a ceramic seal ring with excellent heat resistance is used. .

However, since there is a considerable difference between the coefficient of thermal expansion of ceramics and that of metal, the thermal deformation of the ceramic seal ring does not follow the thermal deformation of the outlet of the metal combustor, and the ceramic Good sealability cannot be obtained even when using a seal ring made by the manufacturer.

Therefore, the object of the present invention is to ensure a good airtightness of the annular space formed at the connection between the ceramic duct which becomes extremely high in temperature and the metal duct which does not become so high in temperature. Is to provide a seal ring that can.

[0008]

A seal ring according to the present invention is a seal ring for sealing an annular space formed in a connecting portion between a ceramic duct and a metal duct. A metal ring having a sealing surface between and a ceramic ring having a sealing surface between the ceramic duct, wherein the ceramic ring is on a surface opposite to the sealing surface of the metal ring. It is characterized in that at least the sealing surface of the ceramic ring is loosely fitted in the formed annular recess so as to project.

[0009]

In the above-mentioned seal ring, the ceramic ring is loosely fitted in the annular recess of the metal ring, and the ceramic ring takes charge of sealing between the ceramic duct and the extremely high temperature. Insulates the metal ring, while the metal ring takes charge of deforming the seal between the metal duct and the metal duct, which does not reach such a high temperature, by following the thermal deformation of the metal duct. .

[0010]

FIG. 3 is a partial cross-sectional view of a single-shaft gas turbine engine as an example in which the seal ring according to the present invention is used. In the figure, reference numeral 1 denotes a turbine rotor shaft having a turbine rotor 1a joined to its tip, and a compressor impeller 2 is fitted to the rotor shaft 1.
Reference numeral 3 denotes a compressor shroud that surrounds the compressor impeller 2 and forms an intake passage before and after compression. Reference numeral 4 denotes an intake air housing fixed to the compressor shroud 3. The plate diffuser 6 is attached to the intake air housing 4 by using the bolt 5 for this fixing, and a continuous intake passage is formed by both.

A main housing 7 which forms the outer shell of the gas turbine engine is attached to the intake air housing 4 by bolts 8, and a rear housing 9 is attached to the rear portion of the main housing 7, which is a chamber into which compressed air flows. 10 is formed. The turbine rotor shaft 1 is cantilevered by a bearing (not shown) fixed to the intake air housing 4.

Reference numeral 11 is a combustor for taking in and burning the compressed air in the chamber 10, and its outlet part is the adapter 1
A scroll duct that guides combustion gas to the turbine rotor 1a is connected to the turbine rotor 1a. Scroll duct
It is formed by a scroll plate 12 that demarcates the compressor portion and the turbine portion, and a scroll-shaped scroll body 14 fixed to the scroll plate 12. The combustion gas after driving the turbine rotor 1a is exhausted to the outside through an exhaust duct 15 connected to the scroll body 14.

In order to drive the turbine rotor 1a efficiently, it is preferable that the combustion gas temperature reaches the maximum temperature immediately before reaching the turbine rotor 1a. As a result, the combustion of the compressed air in the combustor 11 is not completed, but the combustion gas in the middle of this combustion is guided to the scroll duct, and is gradually combusted in the scroll duct while being completely combusted immediately before the turbine rotor 1a. It is like this.

As described above, the temperature of the combustion gas in the combustor 11 is not so high, and the compressed air having a relatively low temperature before combustion is continuously supplied. High heat resistance is not required,
Common metals are used. On the other hand, since the scroll body 14 and the scroll plate 12 forming the scroll duct have a considerably high temperature, ceramics having excellent heat resistance is used as the material thereof.

FIG. 1 is an enlarged sectional view of a connecting portion between the adapter 13 and the scroll body 14. In the figure, the adapter 13 is fixed such that its stepped end portion 13a is inserted into the stepped end portion 14a of the scroll body 14 and is in contact with its shoulder surface 14b.

In the annular groove 13b formed on the outer peripheral surface of the stepped end 13a of the adapter 13, the annular space 20 formed by the stepped end 13a of the adapter 13 and the stepped end 14a of the scroll body 14 is provided. A seal ring 30 for sealing the seal is fitted, and the seal ring 30 is immovable in the axial direction.

The shape of the seal ring 30 is shown in FIG. The seal ring 30 is composed of two rings. As shown in FIG. 2B which is a Q-Q sectional view of FIG. 2A, the first metal ring 31 provided inside is provided.
Has an annular recess 31b formed on its outer surface 31a at least shallower than the thickness of the second ring 32, and the ceramic second ring 32 is loosely fitted in the annular recess 31b. In this loose fitting, the inner surface 32a of the second ring 32 and the bottom surface of the annular recess 31b are not in contact with each other, while both side surfaces 32b of the second ring 32 and both sides of the annular recess 31b are in contact with each other, and In charge of sealing between the second rings 31 and 32. A notch is provided in the two rings 31 and 32 to allow the loose fitting and the fitting of the seal ring 30 into the annular groove 13b of the adapter 13 described above.

The seal ring 30 constructed in this way
Is responsible for the sealing between the inner surface 31c of the first ring 31 and the bottom surface of the annular groove 13b formed in the stepped end 13a of the adapter 13, while the outer surface 32c of the second ring 32 is
Is the inner surface 14 of the stepped end 14a of the scroll body 14.
In charge of sealing with b.

The outer surface 32c of the second ring 32 is in contact with the ceramic scroll body 14 which has a very high temperature, but since the second ring 32 is also made of ceramic, it causes a settling. Without fail, ensuring a good sealability with respect to the scroll body 14.
In addition, the second ring 32 is arranged from the scroll body 14 to the first
Acts as a heat insulating material that reduces the heat transferred to the ring 31,
The settling of the metal first ring 31 is prevented.

The adapter 13 includes heat transferred from the combustor 11 and the scroll body 14 to the first and second rings 3.
The heat transmitted through 1 and 32 causes thermal deformation, but the temperature of the combustor 11 is not so high, and the heat of the latter is reduced by the second ring 32. This thermal deformation should be small. You can More metal first
Since the ring 31 is not constrained in the radial direction and the circumferential direction with respect to the second ring 32, the ring 31 is deformed following the thermal deformation of the adapter 13 while maintaining a good sealing property between the rings 31 and 32. And ensures a good seal against the adapter 13.

As a result, a good seal is realized at the connecting portion between the adapter 13 and the scroll body 14,
Leakage of combustion gas can be prevented and the efficiency of the gas turbine can be improved.

The widths of the cuts provided in both rings 31, 32 are determined so as to be eliminated by the thermal expansion in the circumferential direction during the use of each ring, and the cuts of both rings are set so as not to overlap each other, so that both rings are It is possible to improve the sealing property at the break of 31, 32.

In the present embodiment, the case where the ceramic scroll body 14 is connected to the outside of the metal adapter 13 has been described. On the contrary, in the connection in which the metal adapter 13 is to the outside, the seal ring 30 is connected. The same effect can be obtained by reversing the inside and the outside of the first ring 31 made of metal and the second ring 31 made of ceramic.

According to this embodiment, as described above, the heat insulation of the second ring 32 causes the scroll body 14 of high temperature to be heated.
The heat transferred from the to the adapter 13 is reduced, which
As the material of the adapter 13 and the combustor 11, an inexpensive material having low heat resistance can be used.

[0025]

As described above, according to the seal ring of the present invention, a ceramic duct which has an extremely high temperature,
In an annular space formed by a metal duct that does not have such a high temperature, a ceramic ring having excellent heat resistance provides a good seal with the ceramic duct without causing fatigue. The metal ring, into which the ceramic ring is loosely fitted, deforms following the thermal deformation of the metal duct while maintaining the sealing property between the two rings without causing fatigue due to the high heat insulation of the ceramic ring. Provides a good seal between metal ducts.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a connecting portion between an adapter and a scroll body.

2A is a plan view of a seal ring according to the present invention, and FIG. 2B is a QQ enlarged sectional view of FIG.

FIG. 3 is a partial cross-sectional view of a gas turbine engine in which a seal ring according to the present invention is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Turbine rotor shaft 2 ... Compressor impeller 11 ... Combustor 12 ... Scroll plate 13 ... Adapter 14 ... Scroll body 20 ... Annular space 30 ... Seal ring 31 ... First ring 31b ... Annular recess 31c ... Inner surface 32 ... Second ring 32c ... outer surface

Claims (1)

[Claims] 1. A ceramic duct and a seal ring for sealing an annular space formed in a connection portion with the metal duct, the metal ring having a sealing surface between the duct and the metal duct. A ceramic ring having a sealing surface between the ceramic duct and
The seal ring, wherein the ceramic ring is loosely fitted in an annular recess formed on the surface opposite to the seal surface of the metal ring so that at least the seal surface of the ceramic ring projects. .