Seal member manufacturing method, and seal layer porosity controlling method

Abstract

To improve durability by restraining damage due to erosion while maintaining cutting comfort.SOLUTION: In a seal member manufacturing method, leakage of fluid passing through a space between a rotor and a stator arranged on an outer peripheral side of the rotor is reduced. The seal member has a first seal layer having a first porosity, and a second seal layer arranged on an inner peripheral side of the first seal layer and having second porosity lower than the first porosity. The method has a step of flame-spraying a raw material containing a first content of a resin material to a base material to form the first seal layer, and a step of flame-spraying a raw material containing a second content of the resin material smaller than the first content to the first seal layer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a sealing member and a method for controlling the porosity of a sealing layer.

Background Art

[0002] Rotating machines such as gas turbines and steam turbines are provided with shaft seal devices. The shaft seal device is disposed between a rotor and a stator that is disposed on the outer side in the radial direction of the rotor and surrounds the rotor. The shaft seal device partitions the space between the rotor and the stator into one side and the other side in the axial direction along the central axis of the rotor. The shaft seal device suppresses leakage of the working fluid from the high-pressure side region where the working fluid flows to the low-pressure side region on the other side in the axial direction.

[0003] Among such shaft seal devices, there are those using abradable materials. For example, Patent Document 1 describes a shaft seal device including a seal fin provided on either one of a rotor (rotating part) and a stator (stationary part), and a coating layer that faces the seal fin and covers the base material of the rotor or the stator. In this shaft seal device, a configuration using an abradable material for the coating layer is disclosed. The abradable material is excellent in the property of being cut when sliding in contact with the seal fin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, an abradable material as described in Patent Document 1 is a porous material. Therefore, an effect of suppressing heat generation and vibration when slidingly contacting the seal fin can be obtained. On the other hand, an abradable material made of a porous material may undergo erosion-induced material loss over a long period of use. Therefore, there was room for improvement in terms of durability.

[0006] The present disclosure has been made to solve the above problems, and an object thereof is to provide a method for manufacturing a seal member and a method for controlling the porosity of a seal layer that can suppress damage due to erosion and improve durability while maintaining machinability.

Means for Solving the Problems

[0007] In order to solve the above problems, a method for manufacturing a seal member according to the present disclosure is a method for manufacturing a seal member that reduces leakage of fluid passing through a space between a rotor and a stator disposed on the outer peripheral side of the rotor, the seal member including a first seal layer having a first porosity and a second seal layer disposed on the inner peripheral side of the first seal layer and having a second porosity lower than the first porosity, and includes a step of spraying a raw material containing a resin material with a first content onto a base material to form the first seal layer, and a step of spraying a raw material containing a resin material with a second content less than the first content onto the first seal layer.

[0008] A method for controlling the porosity of a seal layer according to the present disclosure is a method for controlling the porosity of a seal layer formed on the surface of a seal member that reduces leakage of fluid passing through a space between a rotor and a stator disposed on the outer peripheral side of the rotor, and controls the porosity by the content of the resin material of the raw material to be sprayed, the spraying speed, and / or the spraying angle.

Effects of the Invention

[0009] According to the method for manufacturing a seal member and the method for controlling the porosity of a seal layer of the present disclosure, it is possible to suppress damage due to erosion and improve durability while maintaining machinability.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Hereinafter, with reference to the accompanying drawings, embodiments for implementing a shaft seal device and a rotating machine according to the present disclosure will be described. However, the present disclosure is not limited only to these embodiments.

[0012] (First Embodiment) (Configuration of Rotating Machine) As shown in FIG. 1, the rotating machine 1 in the present embodiment is, for example, a gas turbine. The rotating machine 1 includes a compressor 2, a combustor 3, a turbine 4, a rotor 5, and a shaft seal device 10A.

[0013] The compressor 2 takes in a large amount of air and compresses it. The combustor 3 mixes fuel with the air compressed by the compressor 2 and burns it. The turbine 4 has combustion gas generated by the combustor 3 introduced therein. The turbine 4 converts the thermal energy of the introduced combustion gas into rotational energy and generates power to rotate the rotor 5 around the central axis O. The rotor 5 extends cylindrically in the axial direction Da along the central axis O. The rotor 5 transmits a part of the rotational power of the turbine 4 to the compressor 2 to drive the compressor 2.

[0014] For the convenience of the following description, the direction in which the central axis O extends is defined as the axial direction Da. Also, the radial direction in the rotor 5 and the shaft seal device 10A with respect to the central axis is simply defined as the radial direction Dr. Further, the side approaching the central axis O in this radial direction Dr is defined as the inner side Dri of the radial direction Dr, and the side opposite to the inner side Dri of the radial direction Dr in this radial direction Dr is defined as the outer side Dro of the radial direction Dr. Also, the circumferential direction of the rotor 5 and the shaft seal device 10A centered on the central axis O is simply defined as the circumferential direction Dc.

[0015] The turbine 4 includes a turbine rotor blade 7b, a turbine stator blade 6b as a stator 6, and a turbine casing 8. The turbine rotor blade 7b is arranged on the outer side Dro of the radial direction Dr with respect to the rotor 5. The turbine 4 converts the thermal energy of the combustion gas into mechanical rotational energy by spraying the combustion gas onto the turbine rotor blade 7b to generate power. The turbine casing 8 is formed in a cylindrical shape extending in the axial direction Da. The turbine stator blade 6b is arranged on the inner side Dri of the radial direction Dr with respect to the turbine casing 8. The turbine rotor blade 7b and the turbine stator blade 6b are alternately arranged in the axial direction Da. The turbine rotor blade 7b receives the pressure of the combustion gas flowing in the axial direction of the rotor 5 and rotates the rotor 5 around the axis. The rotational energy given to the rotor 5 is taken out from the shaft end and utilized.

[0016] In the turbine 4, a shaft seal device 10A is arranged between the turbine stator blade 6b as a stator 6 and the rotor 5 to reduce the leakage amount of the combustion gas leaking from the high-pressure side to the low-pressure side.

[0017] The compressor 2 is coaxially connected to the turbine 4 via the rotor 5. The compressor 2 compresses outside air using the rotation of the turbine 4 to generate compressed air. The compressor 2 supplies the generated compressed air to the combustor 3. The compressor 2 includes a compressor stator vane 6a as a stator 6, a compressor rotor vane 7a, and a compressor casing 9. The compressor rotor vane 7a is disposed on the outer side Dro in the radial direction Dr with respect to the rotor 5. The compressor casing 9 extends cylindrically in the axial direction Da. The compressor stator vane 6a is disposed on the inner side Dri in the radial direction Dr with respect to the compressor casing 9. The compressor rotor vane 7a and the compressor stator vane 6a are alternately arranged in the axial direction Da of the rotor 5.

[0018] Also in the compressor 2, an axial seal device 10A for reducing the leakage amount of compressed air leaking from the high-pressure side to the low-pressure side is disposed between the compressor stator vane 6a as the stator 6 and the rotor 5.

[0019] In addition, axial seal devices 10A for suppressing leakage of compressed air or combustion gas from the high-pressure side to the low-pressure side are also disposed in the bearing portions 9a and 9b that support the rotor 5 with respect to the compressor casing 9 and the bearing portions 8a and 8b that support the rotor 5 with respect to the turbine casing 8, respectively.

[0020] (Configuration of the axial seal device) The axial seal device 10A seals the annular space between the rotor 5 and the stator 6 that covers the rotor 5 in order to reduce the leakage amount of fluid leaking from the high-pressure side to the low-pressure side. As shown in FIG. 2, the axial seal device 10A is disposed between the rotor 5 and the stator 6. In the present embodiment, in the compressor 2, the stator 6 is the turbine stator vane 6b. In the turbine 4, the stator 6 is the turbine stator vane 6b. Further, for example, in the bearing portions 9a and 9b, the stator 6 is the compressor casing 9 disposed on the outer side Dro in the radial direction Dr of the rotor 5. Also, the stator 6 is, for example, the turbine casing 8 disposed on the outer side Dro in the radial direction Dr of the rotor 5 in the bearing portions 8a and 8b of the turbine 4.

[0021] The shaft seal device 10A is disposed in an annular space 15 between the rotor 5 and the stator 6. The stator 6 is disposed on the outer side Dro in the radial direction Dr with respect to the rotor 5. The rotor 5 has an outer peripheral surface 5f facing the outer side Dro in the radial direction Dr. The stator 6 has an inner peripheral surface 6g facing the inner side Dri in the radial direction Dr. The inner peripheral surface 6g faces the outer peripheral surface 5f of the rotor 5 with a gap in the radial direction Dr. The annular space 15 is formed between the outer peripheral surface 5f of the rotor 5 and the inner peripheral surface 6g of the stator 6. The annular space 15 is formed in an annular shape when viewed from the axial direction Da. The annular space 15 is continuous in the circumferential direction Dc (see FIG. 1).

[0022] The shaft seal device 10A partitions the annular space 15 into a first side Da1 and a second side Da2 in the axial direction Da. In the present embodiment, for example, the annular space 15 on the first side Da1 in the axial direction Da with respect to the shaft seal device 10A is a low-pressure side region S1. The annular space 15 on the second side Da2 in the axial direction Da with respect to the shaft seal device 10A is a high-pressure side region S2. The low-pressure side region S1 is a region through which low-pressure fluid (low-pressure gas or liquid) flows. The high-pressure side region S2 is a region through which high-pressure fluid (high-pressure gas or liquid) having a pressure higher than that of the low-pressure fluid flowing through the low-pressure side region S1 flows. Therefore, with the shaft seal device 10A as a boundary, in the annular space 15, a fluid flow from the high-pressure side region S2 toward the low-pressure side region S1 occurs. The shaft seal device 10A of the present embodiment includes a plurality of fins 21 and a seal member 30A.

[0023] (Configuration of fins) The plurality of fins 21 are arranged on the outer peripheral surface 5f of the rotor 5. The plurality of fins 21 are arranged at intervals in the axial direction Da. Each fin 21 is integrally formed on the outer peripheral surface 5f of the rotor 5. Each fin 21 extends continuously in the circumferential direction Dc around the central axis O. Each fin 21 is formed in an annular shape when viewed from the axial direction Da. The fin 21 protrudes from the rotor 5 toward the stator 6 in the radial direction Dr. That is, each fin 21 extends from the outer peripheral surface 5f of the rotor 5 to the outside Dro in the radial direction Dr. The width dimension of each fin 21 in the axial direction Da gradually decreases from the inner side Dri to the outer side Dro in the radial direction Dr. That is, each fin 21 is formed in a tapered shape so as to become thinner as it approaches the tip.

[0024] Note that the cross-sectional shape of each fin 21, the protruding dimension from the outer peripheral surface 5f to the outside Dro in the radial direction Dr, etc. are not limited to the shape of the present embodiment. The cross-sectional shape of each fin 21, the protruding dimension from the outer peripheral surface 5f to the outside Dro in the radial direction Dr, etc. can be appropriately changed in correspondence with the arrangement of the shaft seal device 10A.

[0025] (Configuration of the seal member) The seal member 30A is arranged at a position facing the plurality of fins 21 in the radial direction Dr. The seal member 30A of the present embodiment is arranged on the inner peripheral surface 6g of the stator 6. The seal member 30A is arranged in a region overlapping the plurality of fins 21 in the axial direction Da. The seal member 30A has a base material 31, a first seal layer 32A, and a second seal layer 33A.

[0026] The base material 31 is held on the inner peripheral surface 6g of the stator 6. The base material 31 may be fixed to the inner peripheral surface 6g of the stator 6, or may be held so as to be relatively movable with respect to the stator 6 in at least one of the radial direction Dr, the axial direction Da, and the circumferential direction Dc.

[0027] The first seal layer 32A is disposed on the inner side Dri in the radial direction Dr with respect to the base material 31. The first seal layer 32A is formed so as to cover the base material 31 from the inner side Dri in the radial direction Dr.

[0028] The second seal layer 33A is laminated at a position close to the fins 21 with respect to the first seal layer 32A. That is, the second seal layer 33A is laminated on the inner side Dri in the radial direction Dr with respect to the first seal layer 32A. The second seal layer 33A is formed so as to cover the first seal layer 32A from the inner side Dri in the radial direction Dr. The second seal layer 33A forms a contact surface 33s with the plurality of fins 21 in the seal member 30A. In the present embodiment, the first seal layer 32A and the second seal layer 33A have the same thickness in the radial direction Dr.

[0029] The first seal layer 32A and the second seal layer 33A are each formed of a porous abradable material. The abradable material is a material having characteristics (machinability) that are easily shaved. Thereby, the second seal layer 33A, together with the first seal layer 32A, constitutes an abradable layer 35 in the seal member 30A. The abradable layer 35 (the first seal layer 32A and the second seal layer 33A) made of the abradable material is capable of contacting the plurality of fins 21 that rotate in the circumferential direction Dc together with the rotor 5 during the operation of the rotary machine 1. At that time, the abradable layer 35 is shaved by sliding with the plurality of fins 21 rotating in the circumferential direction Dc. The seal member 30A enhances the sealing performance between the low-pressure side region S1 and the high-pressure side region S2 by narrowing the clearance in the radial direction Dr between the plurality of fins 21 and the second seal layer 33A to a contactable level.

[0030] As the abradable material, a porous material that is softer than the material forming the plurality of fins 21 is used. The abradable material of the present embodiment is, for example, a metal material mainly containing an MCrAlY alloy. The "M" in the above MCrAlY alloy indicates a metal element. This metal element "M" consists of, for example, a single metal element such as NiCo, Ni, Co, or a combination of two or more of these. More specifically, in the present embodiment, as the abradable material forming the seal member 30A, for example, an alloy mainly containing a CoNiCrAlY alloy and containing polyester is used. By using a metal material containing a resin material such as polyester, void portions of the multi-material are efficiently formed.

[0031] The first seal layer 32A and the second seal layer 33A are formed of the same material. That is, the first seal layer 32A and the second seal layer 33A are formed using a metal material having the same composition. The first seal layer 32A and the second seal layer 33A differ only in porosity. In this specification, the fact that the first seal layer 32A and the second seal layer 33A are formed of the same composition alloy while having different porosities is expressed as "formed of the same material".

[0032] Also, the porosity can be obtained by visually checking the images of the structures of the first seal layer 32A and the second seal layer 33A with a transmission electron microscope (TEM) or a scanning electron microscope (SEM), or by binarizing them into black and white and calculating the area ratio.

[0033] The first seal layer 32A has a first porosity H1. The second seal layer 33A has a second porosity H2 that is lower than the first porosity H1 of the first seal layer 32A.

[0034] Here, the difference ΔH between the first porosity H1 in the first seal layer 32A and the second porosity H2 in the second seal layer 33A is preferably, for example, 10% or more and 40% or less. Also, the first porosity H1 in the first seal layer 32A is preferably, for example, 60% or more and 70% or less. The second porosity H2 in the second seal layer 33A is preferably, for example, 40% or more and 50% or less.

[0035] The first seal layer 32A and the second seal layer 33A are sequentially formed, for example, by spraying a metallic material, which is an abradable material as described above, onto the base material 31. Here, in order to vary the porosity between the first seal layer 32A and the second seal layer 33A, for example, the spraying angle of the spraying gun 100 for spraying the metallic material may be changed. As shown in FIG. 3, when forming the first seal layer 32A, the spraying angle of the spraying gun 100 is set as a first angle θ1 with respect to the surface direction along the surface 31f facing the inner side Dri in the radial direction Dr on the base material 31. Here, the first angle θ1 is preferably, for example, 70° ≤ θ1 ≤ 90°. On the other hand, as shown in FIG. 4, when forming the second seal layer 33A, the spraying angle of the spraying gun 100 is set as a second angle θ2 smaller than the first angle θ1 with respect to the surface direction along the surface 31f of the base material 31. Here, the second angle θ2 is preferably, for example, 50° ≤ θ2 ≤ 60°. Also, the difference Δθ (= θ1 - θ2) between the first angle θ1 and the second angle θ2 is preferably at least 20° or more.

[0036] Also, to change the porosity between the first seal layer 32A and the second seal layer 33A, for example, the moving speed (so-called feed rate) when spraying with the spraying gun 100 may be changed. As shown in FIG. 5, when forming the first seal layer 32A, the moving speed of the spraying gun 100 along the surface 31f of the base material 31 is set to the first speed V1. Here, the first speed V1 is preferably, for example, 40 m / min ≤ V1 ≤ 50 m / min. As shown in FIG. 6, when forming the second seal layer 33A, the moving speed of the spraying gun 100 in the direction along the surface 31f of the base material 31 is set to the second speed V2, which is smaller than the first speed V1. Here, the second speed V2 is preferably, for example, 20 m / min ≤ V2 ≤ 30 m / min. The difference ΔV (= V1 - V2) between the first speed V1 and the second speed V2 is preferably at least 10 m / min or more.

[0037] Also, when forming the first seal layer 32A and the second seal layer 33A made of a porous abradable material as in the present embodiment, when using an alloy containing a resin material as a raw material, to change the porosity between the first seal layer 32A and the second seal layer 33A, for example, the content of the resin material may be changed. The resin material is melted at a high temperature when sprayed onto the base material 31. As a result, cavities are formed in the portions where the resin material is removed, becoming pores. For example, when using an alloy mainly containing CoNiCrAlY alloy and containing polyester as in the present embodiment, the content of polyester is changed.

[0038] Specifically, when forming the first seal layer 32A, the content of polyester contained in the raw material of the first seal layer 32A is set to the first content T1. Here, the first content T1 is preferably, for example, 10 wt% ≤ T1 ≤ 20 wt%. The content of polyester contained in the raw material of the second seal layer 33A is set to the second content T2, which is less than the first content T1. Here, the second content T2 is preferably, for example, 5 wt% ≤ T2 ≤ 15 wt%. Also, the difference ΔT (= T1 - T2) between the first content T1 and the second content T2 is preferably at least 5 wt% or more.

[0039] (Function and Effect) In the shaft seal device 10A having the above configuration, the seal member 30A facing the fin 21 includes a first seal layer 32A and a second seal layer 33A. The second seal layer 33A forming the contact surface 33s with the fin 21 has a second porosity H2 that is lower than the first porosity H1 of the first seal layer 32A. Therefore, the second seal layer 33A is denser and harder than the first seal layer 32A. As a result, the second seal layer 33A becomes a hard layer that is less likely to be eroded by erosion compared to the first seal layer 32A. Also, since the first seal layer 32A has a higher porosity than the second seal layer 33A, it becomes a soft layer with excellent machinability compared to the second seal layer 33A. That is, the first seal layer 32A can suppress the heat and vibration generated by the contact of the fin 21. In this way, by laminating the first seal layer 32A and the second seal layer 33A, it is possible to prevent the entire abradable layer 35 of the seal member 30A from becoming too hard or too soft. As a result, by laminating the first seal layer 32A and the second seal layer 33A, as the seal member 30A, it is possible to suppress damage due to erosion and improve durability while maintaining machinability.

[0040] Also, the outermost layer of the seal member 30A forming the contact surface 33s with the fin 21 is formed of the second seal layer 33A having a low porosity. Therefore, the effect of suppressing erosion-induced material loss in the region of the seal member 30A that is most exposed to the fluid can be enhanced.

[0041] Also, the difference ΔH in porosity between the first seal layer 32A and the second seal layer 33A is set to be 10% or more and 40% or less. Therefore, the balance between the machinability of the first seal layer 32A (the effect of suppressing heat and vibration generated by the contact of the fin 21 with the second seal layer 33A) and the erosion resistance of the second seal layer 33A (the effect of suppressing erosion-induced material loss) can be optimized.

[0042] In addition, by setting the second porosity H2 of the second seal layer 33A to be 40% or more and 50% or less, the erosion resistance can be efficiently enhanced. Further, by setting the first porosity H1 of the first seal layer 32A, which is higher than that of the second seal layer 33A, to be 60% or more and 70% or less, the machinability can be efficiently enhanced.

[0043] Also, the first seal layer 32A and the second seal layer 33A are formed of the same material. As a result, although they are made of the same material, the porosities of the first seal layer 32A and the second seal layer 33A are different. Consequently, an abradable layer 35 that suppresses damage due to erosion while maintaining machinability can be easily created.

[0044] By including the first seal layer 32A and the second seal layer 33A as described above, the rotary machine 1 configured as above can suppress damage due to erosion in the shaft seal device 10A and improve durability.

[0045] (Second Embodiment) Next, a second embodiment of the shaft seal device and the rotary machine according to the present disclosure will be described. In the second embodiment described below, components common to the first embodiment are denoted by the same reference numerals in the drawings, and their descriptions are omitted. In the second embodiment, the configuration of the seal member 30B of the shaft seal device 10B is different from that of the first embodiment.

[0046] As shown in FIG. 7, the shaft seal device 10B of the rotary machine 1 according to the present embodiment is disposed between the rotor 5 and the stator 6, similar to the first embodiment. The shaft seal device 10B includes a plurality of fins 21 and a seal member 30B.

[0047] (Configuration of Seal Member) In the seal member 30B, unlike the first embodiment, the thicknesses of the first seal layer 32B and the second seal layer 33B are different from each other. In the seal member 30B of the second embodiment, the thickness t2 of the second seal layer 33B in the radial direction Dr is smaller than the thickness t1 of the first seal layer 32B in the radial direction Dr. In the present embodiment, it is preferable that the thickness t2 of the second seal layer 33B is 10% or more and 40% or less with respect to the total t1 + t2 of the thickness t1 of the first seal layer 32B and the thickness t2 of the second seal layer 33B.

[0048] (Function and effect) In the shaft seal device 10B having the above configuration, the thickness t2 of the second seal layer 33B with a small porosity is made smaller than the thickness t1 of the first seal layer 32B. As a result, the area of the second seal layer 33B becomes smaller, and a machinability close to the performance when the first seal layer 32B is formed alone can be ensured. On the other hand, since at least the surface of the first seal layer 32B is covered with the second seal layer 33B, erosion resistance can also be ensured. As a result, an abradable layer 35B that suppresses damage due to erosion can be created while maintaining machinability.

[0049] Further, the thickness t2 of the second seal layer 33B with a small porosity is 10% or more and 40% or less with respect to the total t1 + t2 of the thickness t1 of the first seal layer 32B and the thickness t2 of the second seal layer 33B. Thereby, an abradable layer 35B that suppresses damage due to erosion to the minimum while maintaining machinability to the maximum can be created.

[0050] In addition, by reducing the porosity of the second seal layer 33B, even if the second seal layer 33B is made very thin, erosion resistance can be effectively maintained. (Other embodiments)

[0051] As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0052] In addition, in each of the above embodiments, the gas turbine was exemplified as the rotary machine 1, but the rotary machine 1 is not limited to the gas turbine. The rotary machine 1 may be any machine having a rotor 5 and a stator 6. Therefore, the rotary machine 1 may be, for example, a steam turbine, a compressor, or a pump.

[0053] Also, in the rotary machine 1, the locations where the shaft seal devices 10A and 10B are arranged may be any region that needs to seal between the rotor 5 and the stator 6, and is not limited in any way.

[0054] Further, in each of the above embodiments, in the second seal layers 33A and 33B, the contact surfaces 33s that contact the plurality of fins 21 are formed in a flat surface shape, but it is not limited to such a structure. In the second seal layers 33A and 33B, the contact surfaces 33s may be surfaces having irregularities so as to protrude inward Dri in the radial direction Dr or recess outward Dro in the radial direction Dr. In the second seal layers 33A and 33B, the contact surfaces 33s may be curved surfaces. In that case, both the first seal layers 32A and 32B and the second seal layers 33A and 33B may be formed to have irregularities or curvatures so as to be parallel to the contact surfaces 33s, or only the second seal layers 33A and 33B may be formed to have irregularities or curvatures on the flat first seal layers 32A and 32B.

[0055] Also, the number of installed fins 21, the installation positions, the cross-sectional shape in the circumferential direction Dc, etc. may be changed as appropriate.

[0056] <Supplementary Note> The shaft seal devices 10A, 10B and the rotary machine 1 described in the embodiment are understood as follows, for example.

[0057] (1) The shaft seal devices 10A and 10B according to the first aspect are disposed between a rotor 5 rotatable about a central axis O and a stator 6 disposed on the outer side Dro in the radial direction Dr with respect to the rotor 5, and an annular space 15 between the outer peripheral surface 5f of the rotor 5 and the inner peripheral surface 6g of the stator 6 is partitioned into a first side Da1 and a second side Da2 in the axial direction Da in which the central axis O extends. The shaft seal devices 10A and 10B include fins 21 protruding from the rotor 5 toward the stator 6 in the radial direction Dr, and seal members 30A and 30B facing the fins 21 in the radial direction Dr. The seal members 30A and 30B include first seal layers 32A and 32B formed of a porous abradable material having a first porosity H1, and are laminated at positions close to the fins 21 with respect to the first seal layers 32A and 32B to form contact surfaces with the fins 21, and second seal layers 33A and 33B formed of a porous abradable material having a second porosity H2 lower than the porosity of the first seal layers 32A and 32B.

[0058] In these shaft seal devices 10A and 10B, the second seal layers 33A and 33B are denser and harder than the first seal layers 32A and 32B. As a result, the second seal layers 33A and 33B become hard layers that are less likely to be eroded compared to the first seal layers 32A and 32B. Further, since the first seal layers 32A and 32B have a higher porosity than the second seal layers 33A and 33B, they become soft layers with excellent machinability compared to the second seal layers 33A and 33B. That is, the first seal layers 32A and 32B can suppress heat and vibration generated by the contact of the fins 21. In this way, by laminating the first seal layers 32A and 32B and the second seal layers 33A and 33B, it is possible to prevent the entire first seal layers 32A and 32B and the second seal layers 33A and 33B of the seal members 30A and 30B from becoming too hard or too soft. As a result, by laminating the first seal layers 32A and 32B and the second seal layers 33A and 33B, as the seal members 30A and 30B, it is possible to suppress damage due to erosion while maintaining machinability and improve durability.

[0059] (2) The shaft seal device 10B according to the second aspect is the shaft seal device 10B of (1), wherein the thickness t2 of the second seal layer 33B in the radial direction Dr is smaller than the thickness t1 of the first seal layer 32B in the radial direction Dr.

[0060] As a result, the area of the second seal layer 33B becomes smaller, and it is possible to ensure machinability with performance close to the case where the first seal layer 32B is formed alone. On the other hand, since at least the surface of the first seal layer 32B is covered with the second seal layer 33B, erosion resistance can also be ensured. As a result, an abradable layer 35B that suppresses damage due to erosion can be created while maintaining machinability.

[0061] (3) The shaft seal device 10B according to the third aspect is the shaft seal device 10B of (2), wherein the thickness t2 of the second seal layer 33B in the radial direction Dr is 10% or more and 40% or less with respect to the total t1 + t2 of the thicknesses t1 and t2 of the first seal layer 32B and the second seal layer 33B in the radial direction Dr.

[0062] Thereby, an abradable layer 35B that suppresses damage due to erosion to the minimum while maintaining machinability to the maximum can be created.

[0063] (4) The shaft seal devices 10A and 10B according to the fourth aspect are the shaft seal devices 10A and 10B of (1) or (3), wherein the difference ΔH between the first porosity H1 in the first seal layers 32A and 32B and the second porosity H2 in the second seal layers 33A and 33B is 10% or more and 40% or less.

[0064] Thereby, the balance between the machinability of the first seal layers 32A and 32B and the erosion resistance of the second seal layers 33A and 33B can be optimized.

[0065] (5) The shaft seal devices 10A and 10B according to the fifth aspect are any one of the shaft seal devices 10A and 10B in (1) or (4), and the first porosity H1 in the first seal layers 32A and 32B is 60% or more and 70% or less, and the second porosity H2 in the second seal layers 33A and 33B is 40% or more and 50% or less.

[0066] Thereby, the second seal layers 33A and 33B can enhance the effect of suppressing the erosion-induced reduction in thickness. Further, the first seal layers 32A and 32B can suppress the heat and vibration generated by the contact of the fins 21 with the second seal layers 33A and 33B.

[0067] (6) The shaft seal devices 10A and 10B according to the sixth aspect are any one of the shaft seal devices 10A and 10B in (1) to (5), and the first seal layers 32A and 32B and the second seal layers 33A and 33B are formed of the same material.

[0068] Thereby, although they are made of the same material, the porosities of the first seal layers 32A and 32B and the second seal layers 33A and 33B are different. As a result, an abradable layer 35 that suppresses erosion damage while maintaining machinability can be easily created.

[0069] (7) The rotating machine 1 according to the seventh aspect includes a rotor 5 rotatable about a central axis O, a stator 6 disposed outside Dro in the radial direction Dr of the rotor 5, and any one of the shaft seal devices 10A and 10B in (1) to (6). Examples of the rotating machine include a gas turbine, a steam turbine, and a compressor.

[0070] Thereby, in the shaft seal devices 10A and 10B, damage due to erosion can be suppressed and durability can be improved.

Explanation of Reference Numerals

[0071] 1... Rotating machine 2... Compressor 3... Combustor 4…Turbine 5…Rotor 5f…Outer peripheral surface 6…Stator 6a…Compressor stator vane 6b…Turbine stator vane 6g…Inner peripheral surface 7a…Compressor rotor vane 7b…Turbine rotor vane 8…Turbine casing 8a, 8b…Bearing part 9…Compressor casing 9a, 9b…Bearing part 10A, 10B…Shaft seal device 15…Annular space 21…Fin 30A, 30B…Sealing member 31…Base material 31f…Surface 32A, 32B…First sealing layer 33A, 33B…Second sealing layer 33s…Contact surface 35, 35B…Abradable layer 100…Thermal spraying gun Da…Axial direction Da1…First side Da2…Second side Dc…Circumferential direction Dr…Radial direction Dri…Inner side Dro…Outer side H1…First porosity H2…Second porosity O…Central axis S1…Low pressure side region S2…High pressure side region T1…First content T2…Second content V1…First speed V2…Second speed t1…Thickness of the first sealing layer t2…Thickness of the second sealing layer θ1…First angle θ2…Second angle

Claims

1. A method for manufacturing a seal member for reducing leakage of fluid passing through a space between a rotor and a stator disposed on the outer peripheral side of the rotor, wherein the seal member includes a first seal layer having a first porosity and a second seal layer disposed on the inner peripheral side of the first seal layer and having a second porosity lower than the first porosity, comprising the steps of spraying a raw material containing a resin material with a first content onto a base material to form the first seal layer, and spraying a raw material containing a resin material with a second content less than the first content onto the first seal layer. A method for manufacturing a seal member, characterized by the above.

2. The method for manufacturing a seal member according to claim 1, characterized in that the difference between the first content and the second content is 5% by weight or more.

3. The method for manufacturing a seal member according to claim 1 or claim 2, characterized in that the first content is 10% by weight or more and 20% by weight or less, and the second content is 5% by weight or more and 15% by weight or less.

4. The method for manufacturing a seal member according to claim 1, characterized in that the resin material is melted by spraying to form cavities in the first seal layer and the second seal layer.

5. The method for manufacturing a seal member according to claim 1, characterized in that the spraying speed when forming the first seal layer is higher than the spraying speed when forming the second seal layer.

6. The method for manufacturing a seal member according to claim 5, characterized in that the difference between the spraying speed when forming the first seal layer and the spraying speed when forming the second seal layer is 10 m / min or more.

7. The method for manufacturing a seal member according to claim 5 or claim 6, characterized in that the spraying speed when forming the first seal layer is 40 m / min or more and 50 m / min or less, and the spraying speed when forming the second seal layer is 20 m / min or more and 30 m / min or less.

8. The method for manufacturing a seal member according to claim 1, characterized in that the spraying angle when forming the first seal layer is larger than the spraying angle when forming the second seal layer.

9. The method for manufacturing a seal member according to claim 8, characterized in that the difference between the spraying angle when forming the first seal layer and the spraying angle when forming the second seal layer is 20° or more.

10. The method for manufacturing a seal member according to claim 8 or claim 9, wherein the spraying angle when forming the first seal layer is 70° or more and 90° or less, and the spraying angle when forming the second seal layer is 50° or more and 60° or less.

11. A method for controlling the porosity of a seal layer formed on the surface of a seal member that reduces leakage of fluid passing through the space between a rotor and a stator disposed on the outer peripheral side of the rotor, The method for controlling the porosity of a seal layer, characterized in that the porosity is controlled by the content of the resin material of the raw material to be sprayed, the spraying speed, and / or the spraying angle.

12. The method for controlling the porosity of a seal layer according to claim 11, characterized in that the porosity of a plurality of seal layers is controlled, and a difference in the content of the resin material of at least 5% by weight or more is set between the plurality of seal layers.

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