WO2024038492A1

WO2024038492A1 - Supercharger seal structure and supercharger

Info

Publication number: WO2024038492A1
Application number: PCT/JP2022/030894
Authority: WO
Inventors: 拓弥江花; 裕二木下
Original assignee: 三菱重工エンジン＆ターボチャージャ株式会社
Priority date: 2022-08-15
Filing date: 2022-08-15
Publication date: 2024-02-22

Abstract

This supercharger seal structure comprises at least a plurality of seal members provided to a seal gap formed between a rotating member, which includes a rotating shaft and a rotating wheel, and a stationary member, which includes a housing that accommodates the rotating member, the seal gap allowing communication between a wheel-accommodating space in which the rotating wheel is accommodated and a bearing-accommodating space in which a bearing is accommodated. The plurality of seal members include a first seal member and a second seal member that is disposed closer to the wheel-accommodating space than is the first seal member. If an angular position is defined such that vertically above the axis of the rotating shaft is 0° and the angle increases along the rotation direction of the rotating shaft, the first seal member is disposed such that the midpoint of an abutment gap (first midpoint) is positioned within the angular position range of −90° to 90°, and the second seal member is disposed such that the difference in angular position between the midpoint of an abutment gap (second midpoint) and the first midpoint is within the range of 90° to 180°.

Description

Supercharger seal structure and supercharger

The present disclosure relates to a seal structure for a supercharger and a supercharger provided with the seal structure for the supercharger.

A supercharger includes a rotor (rotating body) including a rotating shaft, a turbine impeller attached to one side of the rotating shaft, and a compressor impeller attached to the other side of the rotating shaft, and a turbine impeller and a compressor on the rotating shaft. It includes a bearing rotatably supported between the rotor and the impeller, and a casing (stationary body) that houses the rotor and the bearing. The bearings of a supercharger support a rotating shaft that rotates at high speed, so they easily become hot, and if lubrication is insufficient, there is a risk of seizure. For this reason, the bearings are lubricated or cooled by supplying lubricating oil to the bearings. A seal ring is installed in a turbocharger to seal between the outer surface of a rotating body such as a rotor and the inner surface of a stationary body such as a casing in order to prevent lubricating oil supplied to the bearing from leaking to the compressor or turbine side. (For example, see Patent Document 1).

Japanese Patent Application Publication No. 2008-232124

In a supercharger equipped with a sealing mechanism using a seal ring, there is a risk that lubricating oil may leak. Specifically, lubricating oil accumulates in the space (seal gap) between the outer surface of the rotating body to which the seal ring is attached and the inner surface of the stationary body, and the lubricating oil accumulated in the space is transferred to the above-mentioned body with the seal ring in between. There is a risk of leakage to the space on the opposite side. By reducing the above space, lubricating oil leakage can be suppressed, but the above space is determined based on the ease of assembling the turbocharger and the balance between thermal deformation and sealing performance of peripheral parts of the seal ring, and can be easily changed. Can not do it.

In view of the above circumstances, at least one embodiment of the present disclosure provides a seal structure for a supercharger and a supercharger that can suppress the inflow and outflow of fluid through a seal gap formed between a rotating body and a stationary body. The purpose is to provide.

A seal structure for a supercharger according to at least one embodiment of the present disclosure includes:
A seal structure of a supercharger,
a rotating member including at least a rotating shaft of the supercharger and a rotating wheel provided on one end side of the rotating shaft;
a stationary member that includes at least a housing that accommodates the rotating member;
a bearing that rotatably supports the rotating shaft;
A seal gap formed between the rotating member and the stationary member, the seal gap communicating between a wheel housing space in which the rotating wheel is housed and a bearing housing space in which the bearing is housed. a plurality of seal members;
Each of the plurality of seal members is formed in an arc shape extending along the circumferential direction of the rotating shaft, and has a pair of arc end faces facing each other to form an abutment gap;
The plurality of seal members include a first seal member and a second seal member disposed closer to the wheel accommodation space than the first seal member,
In the case where the angular position is defined such that the vertically upward direction with respect to the axis of the rotating shaft is 0° and the angle increases toward the rotation direction of the rotating shaft,
The first seal member is arranged such that the first midpoint, which is the midpoint of the abutment gap of the first seal member, is located within the range of the angular position from -90° to 90°,
The second seal member is configured such that the difference in angular position between the second midpoint, which is the midpoint of the abutment gap of the second seal member, and the first midpoint is within a range of 90° or more and 180° or less. It was arranged so that

A supercharger according to at least one embodiment of the present disclosure includes the supercharger seal structure.

According to at least one embodiment of the present disclosure, a seal structure for a supercharger and a supercharger that can suppress the inflow and outflow of fluid through a seal gap formed between a rotating body and a stationary body are provided.

FIG. 1 is a schematic cross-sectional view along the axis of a supercharger including a seal structure for a supercharger according to an embodiment. FIG. 1 is a schematic cross-sectional view along the axis of a seal structure of a supercharger according to an embodiment. It is a schematic diagram showing the state where the 1st seal member in the seal structure of the supercharger concerning one embodiment was seen from one side (compressor side) of an axial direction. It is a schematic diagram showing the state where the 2nd seal member in the seal structure of the supercharger concerning one embodiment was seen from one side (compressor side) of an axial direction. FIG. 1 is a schematic cross-sectional view along the axis of a seal structure of a supercharger according to an embodiment. It is a schematic diagram showing the state where the third seal member in the seal structure of the supercharger concerning one embodiment was seen from one side (compressor side) of an axial direction.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, and are merely illustrative examples. do not have.

(supercharger)
FIG. 1 is a schematic cross-sectional view of a supercharger 1 along an axis LA including a seal structure 2 for a supercharger 1 according to an embodiment. The seal structure 2 according to the present disclosure can be installed, for example, in a supercharger (turbocharger) 1 for automobiles, ships, or industries (for example, for land-based power generation). The supercharger 1 is driven by the energy of exhaust gas discharged from an engine (internal combustion engine), not shown, and is configured to compress fluid (for example, air).

As shown in FIG. 1, the supercharger (turbocharger) 1 includes a rotating shaft 11, a compressor wheel 12A connected to one end of the rotating shaft 11, and a turbine connected to the other end of the rotating shaft 11. It includes a wheel 12B, a bearing 13 that rotatably supports the rotating shaft 11, and a housing 14 that supports the bearing 13. The housing 14 accommodates the rotating shaft 11, the compressor wheel 12A, the turbine wheel 12B, and the bearing 13. The rotating shaft 11 is rotatable about the axis LA of the rotating shaft 11 by being supported by a bearing 13 arranged between the compressor wheel 12A and the turbine wheel 12B.

Hereinafter, the direction in which the axis LA of the rotating shaft 11 extends is defined as the axial direction of the rotating shaft 11 (supercharger 1), and the direction perpendicular to the axis LA is defined as the radial direction of the rotating shaft 11 (supercharger 1). The circumferential direction around the axis LA is defined as the circumferential direction of the rotating shaft 11 (supercharger 1). In the axial direction of the rotating shaft 11 (supercharger 1), the side where the compressor wheel 12A is located relative to the turbine wheel 12B is referred to as the compressor side, and the side where the turbine wheel 12B is located relative to the compressor wheel 12A is referred to as the turbine side. do.

The turbine wheel 12B is configured to rotate by the energy of exhaust gas discharged from an engine (not shown) and guided to the turbine wheel 12B. Since the compressor wheel 12A is coaxially connected to the turbine wheel 12B via the rotating shaft 11, it rotates together with the rotating shaft 11 in conjunction with the rotation of the turbine wheel 12B. The supercharger 1 compresses gas (e.g., air) guided to the compressor wheel 12A by rotation of the compressor wheel 12A, increases the density of the gas, and sends the gas to the gas supply destination (e.g., the engine). configured.

In the illustrated embodiment, the compressor wheel 12A is configured to guide air introduced along the axial direction of the supercharger 1 (i.e., the direction in which the axis LA extends) to the outside of the supercharger 1 in the radial direction. It is composed of The turbine wheel 12B is configured to guide exhaust gas introduced from the outside in the radial direction of the supercharger 1 along the axial direction of the supercharger 1. Each of the compressor wheel 12A and the turbine wheel 12B does not include an annular member surrounding the outer periphery of the blade.

(Supercharger seal structure)
Each of FIG. 2 and FIG. 5 is a schematic cross-sectional view along the axis LA of the seal structure 2 of the supercharger 1 according to one embodiment. The seal structure 2 of the supercharger 1 according to some embodiments is a seal structure that is provided in the supercharger 1 to suppress leakage of lubricating oil in the supercharger 1. As shown in FIG. 1, FIG. 2, and FIG. At least a plurality of seal members 5 provided in a seal gap 21 formed in the seal gap 21 are provided.

(rotating parts, stationary parts)
The rotating member 3 is configured to rotate when the supercharger 1 is driven. The rotating member 3 includes at least a rotating shaft 11 and a rotating wheel 12 provided at one end of the rotating shaft 11. The stationary member 4 is configured to remain stationary (do not rotate) even if the rotating member 3 rotates when the supercharger 1 is driven. Stationary member 4 includes at least a housing 14 .

The housing 14 (stationary member 4) accommodates the rotating member 3 and the bearing 13. Inside the housing 14 (stationary member 4), the above-mentioned seal gap 21, a wheel accommodation space 22 in which the rotating wheel 12 is accommodated, and a bearing accommodation space 23 in which the bearing 13 is accommodated are formed. The seal gap 21 is provided between the wheel housing space 22 and the bearing housing space 23 in the axial direction of the rotating shaft 11, and communicates the wheel housing space 22 and the bearing housing space 23.

The rotating member 3 has a rotating side outer circumferential surface 31 that defines a seal gap 21. The stationary member 4 has a stationary inner circumferential surface 41 that defines a seal gap 21 . Each of the rotating side outer circumferential surface 31 and the stationary side inner circumferential surface 41 is formed into an annular shape extending along the circumferential direction of the supercharger 1 . The stationary inner circumferential surface 41 is provided on the outer side in the radial direction of the rotating shaft 11 than the rotating outer circumferential surface 31, and faces the rotating outer circumferential surface 31 with the seal gap 21 formed in an annular shape in between.

(Seal member)
FIG. 3 is a schematic diagram showing the first seal member 5A in the seal structure 2 of the supercharger 1 according to one embodiment, viewed from one side in the axial direction (compressor side). FIG. 4 is a schematic diagram showing the second seal member 5B in the seal structure 2 of the supercharger 1 according to one embodiment, viewed from one side in the axial direction (compressor side). FIG. 6 is a schematic diagram showing a third seal member 5C in the seal structure 2 of the supercharger 1 according to one embodiment, viewed from one side in the axial direction (compressor side). 3, 4, and 6, for reference, a vertical line VL passing through the axis LA and extending in the vertical direction, and a horizontal line HL passing through the axis LA and extending in the horizontal direction are shown.

Each of the plurality of seal members (seal rings) 5 (5A, 5B, 5C) is configured to seal between the stationary side inner peripheral surface 41 and the rotating side outer peripheral surface 31. As shown in FIGS. 3, 4, and 6, each of the plurality of seal members 5 is formed in an arc shape extending along the circumferential direction of the rotating shaft 11, and is a pair of seal members facing each other to form an abutment gap 51. It has circular arc end faces 52 and 53. In the illustrated embodiment, each of the plurality of seal members 5 is made of a metal material and has the same shape (the inner diameter, outer diameter, thickness, and abutment gap size are the same).

Each of the plurality of seal members 5 is arranged in a compressed state along the circumferential direction between the stationary side inner circumferential surface 41 and the rotating side outer circumferential surface 31 so as to narrow the abutment gap, and the stationary side inner circumference Its outer peripheral surface abuts against the surface 41. In the illustrated embodiment, a plurality of annular grooves 32 (32A, 32B, 32C) are formed in the rotation-side outer circumferential surface 31, into which portions (inner circumferential portions) of the seal member 5 are respectively fitted. Each of the plurality of annular grooves 32 is formed in an annular shape extending along the circumferential direction of the rotating shaft 11, and is provided at intervals in the axial direction of the rotating shaft 11. A portion (outer peripheral portion) of each of the plurality of seal members 5 fitted into the annular groove 32 protrudes outward in the radial direction of the rotating shaft 11 beyond the rotation-side outer peripheral surface 31 .

In some other embodiments, the inner circumferential surface of each of the plurality of seal members 5 is brought into contact with the outer circumferential surface 31 of the rotating side without forming the plurality of annular grooves 32 on the outer circumferential surface 31 of the rotating side. It may be . In some other embodiments, a plurality of annular grooves are formed on the stationary side inner circumferential surface 41 at intervals in the axial direction of the rotating shaft 11, and a plurality of seal members are formed in each of the plurality of annular grooves. The outer periphery of each of the parts 5 may be fitted.

(lubricating oil system)
The supercharger 1 is configured such that lubricating oil flows into the bearing 13 and a space in which the bearing 13 is accommodated (bearing accommodation space 23). In the embodiment shown in FIG. 1 , the housing 14 includes a lubricating oil inlet 24 for introducing lubricating oil into its interior, and a lubricating oil supply path 25 for guiding lubricating oil from the lubricating oil inlet 24 to the bearing 13 . and a lubricating oil discharge port 26 for discharging lubricating oil to the outside of the housing 14. The lubricating oil supply path 25 is a flow path defined by the inner wall surface of the housing 14 that communicates the lubricating oil inlet 24 with the bearing housing space 23 . The lubricating oil discharge port 26 is provided below the bearing housing space 23 and communicates with the lower part of the bearing housing space 23 .

The lubricating oil introduced into the housing 14 through the lubricating oil inlet 24 is guided to the bearing 13 through the lubricating oil supply path 25. Most of the lubricating oil guided to the bearing 13 flows downward in the bearing housing space 23 and is discharged to the outside of the housing 14 via the lubricating oil outlet 26 . A portion of the lubricating oil guided to the bearing 13 may flow into the seal gap 21.

(First seal member)
The seal structure 2 of the supercharger 1 according to some embodiments includes the above-mentioned rotating member 3, the above-mentioned stationary member 4, the above-mentioned bearing 13, and a plurality of seal members provided in the above-mentioned seal gap 21. 5. As shown in FIGS. 2 and 5, the plurality of seal members 5 include a first seal member 5A and a second seal member 5B disposed closer to the wheel accommodation space 22 than the first seal member 5A. . In the illustrated embodiment, the plurality of annular grooves 32 include a first annular groove 32A into which the inner circumference of the first seal member 5A is fitted, and a second annular groove into which the inner circumference of the second seal member 5B is fitted. Including groove portion 32B. The second annular groove 32B is formed closer to the wheel accommodation space 22 than the first annular groove 32A.

As shown in FIGS. 3, 4, and 6, the angular position θ is defined such that the vertically upward direction with respect to the axis LA of the rotating shaft 11 is 0°, and the angle increases toward the rotation direction of the rotating shaft 11. do. In the circumferential direction of the rotating shaft 11, the angular range in which the abutment gap 51 is formed (the angular range between the pair of arcuate end surfaces 52 and 53) is preferably 10° or less.

As shown in FIG. 3, the midpoint of the abutment gap 51A (51) formed between the pair of arcuate end surfaces 52A, 53A (52, 53) of the first seal member 5A is defined as a first midpoint MP1. The first seal member 5A is arranged such that the first midpoint MP1 is located within the range of the angular position θ (θ1) from −90° to 90°. In other words, the first seal member 5A is arranged such that the first midpoint MP1 is higher than the horizontal line HL. In the illustrated embodiment, when the seal member 5 is viewed from one side in the axial direction of the rotating shaft 11, the midpoint (intermediate position) between the radial center positions of each of the pair of arcuate end surfaces 52 and 53 is abutment. It is set as the midpoint of the gap.

The lubricating oil adhering to the stationary side inner circumferential surface 41 flows downward in the vertical direction along the stationary side inner circumferential surface 41 due to its own weight, and accumulates in the lower part of the seal gap 21. Therefore, the abutment gap 51 of the seal member 5 is preferably provided above in the vertical direction in order to suppress leakage of lubricating oil through the abutment gap 51. In the first sealing member 5A, it is preferable that the first midpoint MP1 is located within a range where the angular position θ (θ1) is -60° or more and 60° or less, and the angular position θ (θ1) is -30° or more and 30° or less. It is more preferable that the first midpoint MP1 is located within the following range.

(Second seal member)
As shown in FIG. 4, the midpoint of the abutment gap 51B (51) formed between the pair of arcuate end surfaces 52B, 53B (52, 53) of the second seal member 5B is defined as a second midpoint MP2. The second seal member 5B is arranged such that the difference α in the angular position θ between the second midpoint MP2 and the first midpoint MP1 is within the range of 90° or more and 180° or less. The difference α is the difference between the angular position θ1 of the first midpoint MP1 and the angular position θ2 of the second midpoint MP2. Specifically, the difference α is a first imaginary straight line extending from the axis LA and passing through the first midpoint MP1 when the seal members 5 (5A, 5B) are viewed from one side in the axial direction of the rotating shaft 11. It means the smaller angle between the angle L1 (see FIG. 3) and the second virtual straight line L2 extending from the axis LA and passing through the second midpoint MP2.

The larger the difference in angular position θ between the abutment gap 51A of the first seal member 5A and the abutment gap 51B of the second seal member 5B, the greater the pressure loss between the first seal member 5A and the second seal member 5B. Since the lubricating oil increases, it becomes difficult for lubricating oil to leak between the first seal member 5A and the second seal member 5B. Therefore, it is preferable to make the difference α as large as possible. In the second seal member 5B, the difference α is preferably in the range of 120° or more and 180° or less, and more preferably the difference α is in the range of 150° or more and 180° or less.

According to the above configuration, the first sealing member 5A is arranged such that the first midpoint MP1 is located within the range of -90° or more and 90° or less at the angular position θ (θ1). Leakage of lubricating oil through the abutment gap 51A of the seal member 5A can be suppressed. Further, the second seal member 5B is arranged such that the difference α in the angular position θ between the second midpoint MP2 and the first midpoint MP1 is within the range of 90° or more and 180° or less. Leakage of lubricating oil through the abutment gap 51B of the second seal member 5B can be suppressed. Further, according to the above configuration, the seal structure 2 of the supercharger 1 not only prevents fluid (for example, lubricating oil) from flowing out from the bearing accommodation space 23 to the wheel accommodation space 22 via the seal gap 21, but also prevents the sealing. It is also possible to suppress the inflow of fluid (for example, air, exhaust gas, etc.) from the wheel housing space 22 to the bearing housing space 23 via the gap 21.

(Third seal member)
In some embodiments, the plurality of seal members 5, as shown in FIG. It includes a third seal member 5C disposed on the 22 side. In the illustrated embodiment, the plurality of annular grooves 32 include the above-mentioned first annular groove 32A, the above-mentioned second annular groove 32B, and a third annular groove 32C into which the inner circumference of the third seal member 5C is fitted. including. The third annular groove 32C is formed closer to the wheel accommodation space 22 than the second annular groove 32B.

As shown in FIG. 6, the midpoint of the abutment gap 51C (51) formed between the pair of arc end faces 52C, 53C (52, 53) of the third seal member 5C is defined as a third midpoint MP3. The third seal member 5C is arranged such that the difference β in the angular position θ between the third midpoint MP3 and the second midpoint MP2 is within the range of 90° or more and 180° or less. The difference β is the difference between the angular position θ2 of the second midpoint MP2 and the angular position θ3 of the third midpoint MP3. Specifically, the difference β is determined by a second virtual straight line extending from the axis LA and passing through the second midpoint MP2 when the seal members 5 (5B, 5C) are viewed from one side in the axial direction of the rotating shaft 11. It means the smaller angle between the angle L2 (see FIG. 4) and the third virtual straight line L3 extending from the axis LA and passing through the third midpoint MP3.

The larger the difference in angular position θ between the abutment gap 51B of the second seal member 5B and the abutment gap 51C of the third seal member 5C, the greater the pressure loss between the second seal member 5B and the third seal member 5C. Since the lubricating oil increases, it becomes difficult for lubricating oil to leak between the second seal member 5B and the third seal member 5C. Therefore, it is preferable to make the difference β as large as possible. In the third seal member 5C, the difference β is preferably in the range of 120° or more and 180° or less, and more preferably the difference β is in the range of 150° or more and 180° or less.

According to the above configuration, the third seal member 5C is arranged such that the difference β in the angular position θ between the third midpoint MP3 and the second midpoint MP2 is within the range of 90° or more and 180° or less. By doing so, leakage of lubricating oil through the abutment gap 51C of the third seal member 5C can be suppressed.

In some embodiments, the second seal member 5B is arranged such that the second midpoint MP2 is located within a range where the angular position θ (θ2) is 90° or more and 270° or less, as shown in FIG. has been done. The third seal member 5C is arranged such that the third midpoint MP3 is located within the range of the angular position θ (θ3) from −90° to 90°. In other words, the second seal member 5B is arranged so that the second midpoint MP2 is below the horizontal line HL, and the third seal member 5C is arranged so that the third midpoint MP3 is above the horizontal line HL. .

According to the above configuration, by providing a vertical difference (height difference) between the abutment gap 51B of the second seal member 5B and the abutment gap 51C of the third seal member 5C, the second seal member 5B The lubricating oil that has passed through the abutment gap 51B becomes difficult to pass through the abutment gap 51C of the third seal member 5C. Thereby, leakage of lubricating oil via the abutment gap 51C of the third seal member 5C can be suppressed.

In the illustrated embodiment, the second seal member 5B is arranged such that the second midpoint MP2 is below the horizontal line HL, but in some other embodiments, the second midpoint MP2 is It may be located above the horizontal line HL. Further, in the illustrated embodiment, the third seal member 5C is arranged such that the third midpoint MP3 is equal to or higher than the horizontal line HL, but in some other embodiments, the third midpoint MP3 is It may be located below the horizontal line HL. For example, the plurality of seal members 5 (5A, 5B, 5C) may be arranged such that the first midpoint MP1, the second midpoint MP2, and the third midpoint MP3 are all higher than the horizontal line HL.

Further, in some embodiments, differences may be provided in the intervals between the abutment gaps 51 of the plurality of seal members 5. For example, the abutment gap 51 of the seal member 5 (5B in the illustrated example) whose midpoint is disposed below the horizontal line HL is set to the abutment gap 51 of the seal member 5 (5A, 5C in the illustrated example) whose midpoint is disposed above the horizontal line HL. The gap may be smaller than the abutment gap 51. In this case, leakage of the lubricating oil through the abutment gap 51 can be suppressed by narrowing the abutment gap 51 located below where the lubricant oil accumulates.

(Compressor wheel accommodation space)
In some embodiments, as shown in FIG. 1, the wheel accommodation space 22 described above includes a compressor wheel accommodation space 22A in which a compressor wheel 12A is accommodated. The seal structure 2 (2A) of the supercharger 1 is for suppressing leakage of lubricating oil from the bearing accommodation space 23 to the compressor wheel accommodation space 22A. The rotating wheel 12 of the supercharger seal structure 2A includes the compressor wheel 12A described above. As shown in FIG. 1, the compressor wheel accommodating space 22A or the seal gap 21A (21) arranged between the compressor wheel accommodating space 22A and the bearing accommodating space 23 is closer to the bearing accommodating space 23 in which the bearing 13 is accommodated. is also provided on the compressor side in the axial direction of the rotating shaft 11. The rotation-side outer circumferential surface 31A (31) may be, for example, the outer circumferential surface of an annular sleeve 15 included in the supercharger 1, as shown in FIG. The sleeve 15 is attached to the rotary shaft 11 between the compressor wheel 12A (rotary wheel 12) and the bearing 13 in the axial direction of the rotary shaft 11 so as to cover the outer periphery of the rotary shaft 11.

The rotating member 3 may further include a sleeve 15. The stationary side inner circumferential surface 41A (41) may be an inner wall surface of the housing 14 that faces the outer circumferential surface of the sleeve 15 with the seal gap 21A in between. Note that in some other embodiments, the rotation-side outer peripheral surface 31 may be the outer peripheral surface of the rotation shaft 11.

According to the above configuration, the seal structure 2 (2A) of the supercharger 1 can suppress leakage of lubricating oil into the compressor wheel housing space 22A via the seal gap 21A. Furthermore, the seal structure 2 (2A) of the supercharger 1 can suppress air, which is the working fluid that operates the compressor wheel 12A, from flowing into the bearing housing space 23 through the seal gap 21A.

(Turbine wheel accommodation space)
In some embodiments, as shown in FIG. 1, the wheel accommodation space 22 described above includes a turbine wheel accommodation space 22B in which the turbine wheel 12B is accommodated. In some embodiments, as shown in FIG. 1, the seal structure 2B(2) of the supercharger is for suppressing leakage of lubricating oil from the bearing housing space 23 to the turbine wheel housing space 22B. be. The rotating wheel 12 of the supercharger seal structure 2B includes the turbine wheel 12B described above. As shown in FIG. 1, the seal gap 21B (21) arranged between the turbine wheel housing space 22B and the turbine wheel housing space 22B and the bearing housing space 23 is closer to the bearing housing space 23 in which the bearing 13 is housed. is also provided on the turbine side in the axial direction of the rotating shaft 11.

The rotation side outer circumferential surface 31B (31) may be, for example, the outer circumferential surface of a boss portion protruding from the back surface of the turbine wheel 12B, as shown in FIG. The stationary side inner circumferential surface 41B (41) may be an inner wall surface of the housing 14 that faces the outer circumferential surface of the boss portion of the turbine wheel 12B with the seal gap 21B in between.

According to the above configuration, the seal structure 2B(2) of the supercharger 1 can suppress leakage of lubricating oil into the turbine wheel housing space 22B via the seal gap 21B. Further, the seal structure 2B(2) of the supercharger 1 can suppress the exhaust gas, which is the working fluid that operates the turbine wheel 12B, from flowing into the bearing accommodation space 23 through the seal gap 21B.

Note that the supercharger 1 may include both the

seal structures

2A and 2B of the supercharger 1. That is, the present disclosure may be applied to each of the plurality of seal members 5 arranged in the seal gap 21A described above and the plurality of seal members 5 arranged in the seal gap 21B described above.

As shown in FIG. 1, the supercharger 1 according to some embodiments includes at least one of the

seal structures

2A and 2B described above. In this case, the seal structure 2 (2A, 2B) of the supercharger 1 can suppress leakage of fluid such as lubricating oil through the seal gap 21. The seal structure 2 (2A, 2B) of the supercharger 1 described above not only prevents lubricating oil from leaking through the seal gap 21, but also prevents lubricant oil from leaking from the wheel housing space 22 to the bearing housing space 23 through the seal gap 21. Leakage of gas (exhaust gas and air) can also be suppressed.

In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction", "along a certain direction", "parallel", "perpendicular", "center", "concentric", or "coaxial" are used. shall not only strictly represent such an arrangement, but also represent a state in which they are relatively displaced with a tolerance or an angle or distance that allows the same function to be obtained.
For example, expressions such as "same,""equal," and "homogeneous" that indicate that things are in an equal state do not only mean that things are exactly equal, but also have tolerances or differences in the degree to which the same function can be obtained. It also represents the existing state.
In addition, in this specification, expressions expressing shapes such as a square shape or a cylindrical shape do not only mean shapes such as a square shape or a cylindrical shape in a strict geometric sense, but also within the range where the same effect can be obtained. , shall also represent shapes including uneven parts, chamfered parts, etc.
Furthermore, in this specification, the expressions "comprising,""including," or "having" one component are not exclusive expressions that exclude the presence of other components.

The present disclosure is not limited to the embodiments described above, and also includes forms in which modifications are made to the embodiments described above, and forms in which these forms are appropriately combined.

The contents described in the several embodiments described above can be understood, for example, as follows.

1) The seal structure (2) of the supercharger (1) according to at least one embodiment of the present disclosure includes:
A seal structure (2) for a supercharger (1),
a rotating member (3) including at least a rotating shaft (11) of the supercharger (1) and a rotating wheel (12) provided at one end of the rotating shaft (11);
a stationary member (4) comprising at least a housing (14) housing the rotating member (3);
a bearing (13) rotatably supporting the rotating shaft (11);
A sealing gap (21) formed between the rotating member (3) and the stationary member (4), which is a sealing gap (21) formed between the wheel housing space (22) in which the rotating wheel (12) is accommodated and the bearing (13). ), a plurality of seal members (5) provided in a seal gap (21) that communicates with a bearing housing space (23) in which a bearing housing (23) is accommodated;
Each of the plurality of seal members (5) is formed in an arc shape extending along the circumferential direction of the rotating shaft (11), and has a pair of arc end faces () facing each other to form an abutment gap (51). 52, 53),
The plurality of seal members (5) include a first seal member (5A), a second seal member (5B) disposed closer to the wheel accommodation space (22) than the first seal member (5A), including;
In the case where the angular position (θ) is defined such that the vertically upward direction with respect to the axis (LA) of the rotary shaft (11) is 0° and the angle increases toward the rotation direction of the rotary shaft (11),
The first seal member (5A) has a first seal member (5A) whose angular position (θ) is at the midpoint of the abutment gap (51A) of the first seal member (5A) within a range of −90° or more and 90° or less. Arranged so that the midpoint (MP1) is located,
The second seal member (5B) is located between the second midpoint (MP2), which is the midpoint of the abutment gap (51B) of the second seal member (5B), and the first midpoint (MP1). They were arranged so that the difference (α) in the angular position was within a range of 90° or more and 180° or less.

According to configuration 1) above, the first sealing member (5A) is arranged such that the first midpoint (MP1) is located within the range of the angular position (θ) from −90° to 90°. This makes it possible to suppress leakage of lubricating oil through the abutment gap (51A) of the first seal member (5A). Further, the second seal member (5B) has a difference (α) in angular position (θ) between the second midpoint (MP2) and the first midpoint (MP1) within a range of 90° or more and 180° or less. By arranging the lubricating oil through the abutment gap (51B) of the second seal member (5B), it is possible to suppress leakage of lubricating oil through the abutment gap (51B) of the second seal member (5B). Furthermore, according to configuration 1), the seal structure (2) of the supercharger (1) allows fluid to flow from the bearing accommodation space (23) to the wheel accommodation space (22) via the seal gap (21). Not only the outflow but also the inflow of fluid from the wheel housing space (22) to the bearing housing space (23) via the seal gap (21) can be suppressed.

2) In some embodiments, the seal structure (2) of the supercharger (1) described in 1) above,
The plurality of seal members (5) further include a third seal member (5C) disposed closer to the wheel accommodation space (22) than the second seal member (5B),
The third seal member (5C) is located between the third midpoint (MP3), which is the midpoint of the abutment gap (51C) of the third seal member (5C), and the second midpoint (MP2). The arrangement was such that the difference (β) in the angular position was within a range of 90° or more and 180° or less.

According to configuration 2) above, the third seal member (5C) has a difference (β) in angular position (θ) of 90° between the third midpoint (MP3) and the second midpoint (MP2). By arranging the angle within the range of 180° or less, leakage of lubricating oil through the abutment gap (51C) of the third seal member (5C) can be suppressed.

3) In some embodiments, the seal structure (2) of the supercharger (1) described in 2) above,
The second sealing member (5B) is arranged such that the second midpoint (MP2) is located within a range of the angular position (θ) of 90° or more and 270° or less,
The third seal member (5C) was arranged such that the third midpoint (MP3) was located within the range of the angular position (θ) from −90° to 90°.

According to configuration 3) above, there is a difference in the vertical direction (height difference) between the abutment gap (51B) of the second seal member (5B) and the abutment gap (51C) of the third seal member (5C). By providing this, the lubricating oil that has passed through the abutment gap (51B) of the second seal member (5B) becomes difficult to pass through the abutment gap (51C) of the third seal member (5C). Thereby, leakage of lubricating oil through the abutment gap (51C) of the third seal member (5C) can be suppressed.

4) In some embodiments, the seal structure (2) of the supercharger (1) according to any one of 1) to 3) above,
The wheel housing space (22) includes a compressor wheel housing space (22A) in which a compressor wheel (12A) is housed.

According to configuration 4) above, the seal structure (2) of the supercharger (1) can suppress leakage of lubricating oil into the compressor wheel housing space (22A) via the seal gap (21). Furthermore, the seal structure (2) of the supercharger (1) can suppress air, which is the working fluid that operates the compressor wheel (12A), from flowing into the bearing housing space (23) through the seal gap (21). .

5) In some embodiments, the seal structure (2) of the supercharger (1) according to any one of 1) to 3) above,
The wheel housing space (22) includes a turbine wheel housing space (22B) in which a turbine wheel (12B) is housed.

According to configuration 5) above, the seal structure (2) of the supercharger (1) can suppress leakage of lubricating oil into the turbine wheel housing space (22B) via the seal gap (21). Furthermore, the seal structure (2) of the supercharger (1) can suppress the exhaust gas, which is the working fluid that operates the turbine wheel (12B), from flowing into the bearing housing space (23) through the seal gap (21). .

6) A supercharger (1) according to at least one embodiment of the present disclosure,
The seal structure (2) of the supercharger (1) according to any one of 1) to 5) above is provided.

According to configuration 6) above, the seal structure (2) of the supercharger (1) can suppress the inflow and outflow of fluid such as lubricating oil through the seal gap (21).

1

Supercharger

2, 2A, 2B Seal structure 3 Rotating member 4 Stationary member 5 Seal member 5A First seal member 5B Second seal member 5C Third seal member 11 Rotating shaft 12 Rotating wheel

12A Compressor wheel

12B Turbine wheel 13 Bearing 14 Housing 15

Sleeves

21, 21A, 21B Seal gap 22 Wheel housing space 22A Compressor wheel housing space 22B Turbine wheel housing space 23 Bearing housing space 24 Lubricating oil inlet 25 Lubricating oil supply path 26

Lubricating oil outlet

31, 31A, 31B Rotation side Outer peripheral surface 32 Annular groove 32A First annular groove 32B Second annular groove 32C Third

annular groove

41, 41A, 41B Stationary side inner

peripheral surface

51, 51A, 51B,

51C Abutment gap

52, 52A, 52B, 52C, 53, 53A , 53B, 53C Arc end face HL Horizontal line L1 First virtual straight line L2 Second virtual straight line L3 Third virtual straight line LA Axis line MP1 First midpoint MP2 Second midpoint MP3 Third midpoint VL Perpendicular line

Claims

A seal structure of a supercharger,
a rotating member including at least a rotating shaft of the supercharger and a rotating wheel provided on one end side of the rotating shaft;
a stationary member that includes at least a housing that accommodates the rotating member;
a bearing that rotatably supports the rotating shaft;
A seal gap formed between the rotating member and the stationary member, the seal gap communicating between a wheel housing space in which the rotating wheel is housed and a bearing housing space in which the bearing is housed. a plurality of seal members;
Each of the plurality of seal members is formed in an arc shape extending along the circumferential direction of the rotating shaft, and has a pair of arc end faces facing each other to form an abutment gap;
The plurality of seal members include a first seal member and a second seal member disposed closer to the wheel accommodation space than the first seal member,
In the case where the angular position is defined such that the vertically upward direction with respect to the axis of the rotating shaft is 0° and the angle increases toward the rotation direction of the rotating shaft,
The first seal member is arranged such that the first midpoint, which is the midpoint of the abutment gap of the first seal member, is located within the range of the angular position from -90° to 90°,
The second seal member is configured such that the difference in angular position between the second midpoint, which is the midpoint of the abutment gap of the second seal member, and the first midpoint is within a range of 90° or more and 180° or less. arranged so that
Supercharger seal structure.
The plurality of seal members further include a third seal member disposed closer to the wheel accommodation space than the second seal member,
The third seal member is such that the difference in angular position between the third midpoint, which is the midpoint of the abutment gap of the third seal member, and the second midpoint is within a range of 90° or more and 180° or less. arranged so that
A seal structure for a supercharger according to claim 1.
The second seal member is arranged such that the second midpoint is located within a range of the angular position from 90° to 270°,
The third seal member is arranged such that the third midpoint is located within a range of the angular position from −90° to 90°;
A seal structure for a supercharger according to claim 2.
The wheel housing space includes a compressor wheel housing space in which a compressor wheel is housed.
A seal structure for a supercharger according to any one of claims 1 to 3.
The wheel housing space includes a turbine wheel housing space in which a turbine wheel is housed.
A seal structure for a supercharger according to any one of claims 1 to 3.
A supercharger comprising the supercharger seal structure according to any one of claims 1 to 3.