JP2023122357A - Seal structure of supercharger - Google Patents

Abstract

To provide a seal structure of a supercharger which can suppress the leakage of a lubricant.SOLUTION: A seal structure of a supercharger comprises: a rotating member including a rotating shaft of the supercharger and a rotating wheel provided at one end side of the rotating shaft; a stationary member including a housing for accommodating the rotating member; a bearing for rotatably supporting the rotating shaft; and a seal member formed between the rotating member and the stationary member, and provided in a seal clearance which makes a first space in which the rotating wheel is accommodated and a second space in which the bearing is accommodated communicate with each other. The stationary member includes a stationary-side internal peripheral face for defining the seal clearance, and a stationary-side end face extending in a radial direction of the rotating shaft from an edge of the second space side at the stationary-side internal peripheral face. The stationary member has an oil drain groove formed at the stationary-side end face at a lower part lower than an axial line of the rotating shaft, and extending downward in a vertical direction from the edge of the second space side of the stationary-side internal peripheral face.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a supercharger seal structure.

A turbocharger comprises a rotor (rotating body) including a rotating shaft, a turbine impeller mounted on one side of the rotating shaft, and a compressor impeller mounted on the other side of the rotating shaft, and a turbine impeller and a compressor on the rotating shaft. A bearing that rotatably supports the impeller and a casing that houses the rotor and the bearing are provided. Since the bearings of the turbocharger support a rotating shaft that rotates at high speed, they are likely to reach high temperatures, and if lubrication is insufficient, there is a risk of seizure. Therefore, the bearings are lubricated and cooled by supplying lubricating oil to the bearings. A turbocharger has a seal ring that seals 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 leakage of lubricating oil supplied to the bearings to the compressor side or turbine side. (see, for example, Patent Document 1).

JP 2008-232124 A

In a supercharger having a sealing mechanism with a seal ring, there is a risk of leakage of lubricating oil. Specifically, the lubricating oil accumulates in the space 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 moves away from the space with the seal ring interposed therebetween. There is a risk of leakage into the side space.

In view of the circumstances described above, at least one embodiment of the present invention aims to provide a supercharger seal structure capable of suppressing leakage of lubricating oil.

A supercharger seal structure according to at least one embodiment of the present invention includes:
A seal structure for a turbocharger,
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 including 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 providing communication between a first space in which the rotating wheel is accommodated and a second space in which the bearing is accommodated. a sealing member;
The rotating member includes at least a rotating-side outer peripheral surface that defines the seal gap,
The stationary member includes a stationary-side inner peripheral surface that defines the seal gap, a stationary-side end surface that extends along the radial direction of the rotating shaft from an edge of the stationary-side inner peripheral surface on the second space side, including
The stationary member is an oil drain groove provided in the stationary side end surface below the axis of the rotating shaft, and extends vertically downward from the edge of the stationary side inner peripheral surface on the second space side. with oil drain grooves extending toward the

According to at least one embodiment of the present invention, there is provided a supercharger seal structure capable of suppressing leakage of lubricating oil.

1 is a schematic cross-sectional view showing a cross section along an axis of a supercharger having a seal structure for a supercharger according to one embodiment; FIG. 1 is a schematic cross-sectional view showing a cross-section along an axis of a seal structure of a supercharger according to one embodiment; FIG. It is a schematic diagram showing a state where the seal structure of the turbocharger according to one embodiment is viewed from the second space side. It is a schematic diagram showing a state where the seal structure of the turbocharger according to one embodiment is viewed from the second space side. FIG. 3 is a schematic diagram showing a state in which the vicinity of the oil drain groove in the seal structure of the supercharger according to one embodiment is viewed from above. 1 is a schematic cross-sectional view showing a cross-section along an axis of a seal structure of a supercharger according to one embodiment; FIG.

Several embodiments of the present invention will now 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 invention, and are merely illustrative examples. do not have.

(supercharger)
FIG. 1 is a schematic cross-sectional view showing a cross section along the axis of a turbocharger provided with a turbocharger seal structure according to one embodiment. As shown in FIG. 1, the supercharger 1 includes a rotating shaft 11, a compressor wheel 12A provided on one end side of the rotating shaft 11, a turbine wheel 12B provided on the other end side of the rotating shaft 11, A bearing 13 that rotatably supports the rotating shaft 11 , and a housing 14 that houses the rotating shaft 11 , the compressor wheel 12A, the turbine wheel 12B, and the bearing 13 are provided.

Bearing 13 is supported by housing 14 . The rotary shaft 11 is supported by bearings 13 between the compressor wheel 12A and the turbine wheel 12B, so that the rotary shaft 11 can rotate about the axis LA.

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). Define. In the axial direction of the rotating shaft 11 (supercharger 1), the side where the compressor wheel 12A is positioned with respect to the turbine wheel 12B is called the compressor side, and the side where the turbine wheel 12B is positioned with respect to the compressor wheel 12A is called the turbine side. do.

Turbine wheel 12B is configured to rotate due to the energy of the exhaust gas discharged from the engine directed to turbine wheel 12B. The compressor wheel 12A rotates together with the rotating shaft 11 in conjunction with the rotation of the turbine wheel 12B. The turbocharger 1 compresses the gas (for example, air) guided to the compressor wheel 12A by the rotation of the compressor wheel 12A, increases the density of the gas, and sends the gas to the destination (for example, the engine). Configured.

(Turbocharger seal structure)
FIG. 2 is a schematic cross-sectional view showing a cross section along the axis of the seal structure of the supercharger according to one embodiment. FIG. 2 shows a region surrounded by a chain double-dashed line in FIG. Each of FIGS. 3 and 4 is a schematic diagram showing a state of the sealing structure of the turbocharger according to one embodiment, viewed from the second space side. FIG. 5 is a schematic view showing the vicinity of the oil drain groove in the seal structure of the turbocharger according to one embodiment, as viewed from above. A supercharger seal structure 2 according to some embodiments is a seal structure for suppressing leakage of lubricating oil in the supercharger 1 provided in the supercharger 1 . As shown in FIG. 1, the seal structure 2 of the supercharger includes a rotating member 3, a stationary member 4 that accommodates the rotating member 3, and a seal gap 20 formed between the rotating member 3 and the stationary member 4. and the bearing 13 described above.

(Rotating member, stationary member)
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 on one end side of the rotating shaft 11 . The stationary member 4 is configured to remain stationary (not rotate) even if the rotating member 3 rotates when the supercharger 1 is driven. The stationary member 4 includes at least a housing 14 .

The stationary member 4 (housing 14 ) accommodates the rotating member 3 and bearings 13 . Inside the stationary member 4 (housing 14), the aforementioned seal gap 20, a first space 21 in which the rotating wheel 12 is accommodated, and a second space 22 in which the bearing 13 is accommodated are formed. The seal gap 20 is provided between the first space 21 and the second space 22 in the axial direction of the rotating shaft 11 to communicate the first space 21 and the second space 22 .

The rotary member 3 has a rotary-side outer peripheral surface 31 that defines the seal gap 20 . The stationary member 4 has a stationary inner peripheral surface 41 that defines the sealing gap 20 . The stationary-side inner peripheral surface 41 is provided radially outwardly of the rotating shaft 11 relative to the rotating-side outer peripheral surface 31 and faces the rotating-side outer peripheral surface 31 with an annular seal gap 20 therebetween.

As shown in FIG. 2 , the stationary member 4 is a stationary member that extends outward in the radial direction along the radial direction of the rotating shaft 11 from an edge 42 of the stationary side inner peripheral surface 41 on the side of the second space 22 . It has a side end face 43 . As shown in FIG. 2, the rotating member 3 has a rotating side extending inward in the radial direction along the radial direction of the rotating shaft 11 from an edge 32 of the rotating side outer peripheral surface 31 on the second space 22 side. It may have an end surface 33 .

(Seal member)
The seal member 5 is configured to seal between the stationary-side inner peripheral surface 41 and the rotating-side outer peripheral surface 31 . In the illustrated embodiment, the seal member (seal ring) 5 is arranged in a compressed state between the stationary side inner peripheral surface 41 and the rotating side outer peripheral surface 31 as shown in FIG. The outer peripheral surface abuts against the inner peripheral surface 41 and the inner peripheral surface abuts against the rotation-side outer peripheral surface 31 . As shown in FIGS. 1 and 2, at least one of the stationary-side inner peripheral surface 41 and the rotating-side outer peripheral surface 31 has a groove extending in the circumferential direction of the rotary shaft 11 for fitting a portion of the seal member 5 thereon. An annular groove extending therealong may be provided.

(Lubricating oil system)
The turbocharger 1 is configured such that lubricating oil flows into the bearing 13 and the second space 22 in which the bearing 13 is accommodated. In the embodiment shown in FIG. 1 , the housing 14 has a lubricating oil inlet 23 for introducing lubricating oil therein, and a lubricating oil supply path 24 for guiding the lubricating oil from the lubricating oil inlet 23 to the bearing 13 . and a lubricating oil discharge port 25 for discharging the lubricating oil to the outside of the housing 14 . The lubricating oil supply path 24 is a flow path defined by the inner wall surface of the housing 14 and communicating between the lubricating oil inlet 23 and the second space 22 . The lubricating oil discharge port 25 is provided below the second space 22 and communicates with the lower portion of the second space 22 .

The lubricating oil introduced into the housing 14 through the lubricating oil inlet 23 is guided to the bearing 13 through the lubricating oil supply path 24 . Most of the lubricating oil guided to the bearing 13 flows downward in the second space 22 and is discharged to the outside of the housing 14 through the lubricating oil discharge port 25 . A part of the lubricating oil guided to the bearing 13 may flow into the seal gap 20 .

The seal structure 2 of the turbocharger 1 according to some embodiments includes the rotating member 3 described above, the stationary member 4 described above, the bearing 13 described above, and the seal member 5 provided in the seal gap 20 described above. , provided. The stationary member 4 includes the stationary inner peripheral surface 41 described above and the stationary side end surface 43 described above. The stationary side end face 43 has an oil drain groove 6 provided in the stationary side end face 43 below the axis LA of the rotating shaft 11, as shown in FIGS. The oil drain groove 6 extends downward along the vertical direction from an edge 42 of the stationary inner peripheral surface 41 on the second space 22 side. Hereinafter, the direction orthogonal to the extending direction of the oil drain groove 6 is defined as the width direction of the oil drain groove 6 . The width direction of the oil drain groove 6 extends along the horizontal direction perpendicular to the axis LA of the rotating shaft 11 .

The stationary side end face 43 further has a flat face 43A provided outside the region where the oil drain groove 6 is formed, as shown in FIGS. The flat surface 43A extends outward along the radial direction of the rotating shaft 11 from the edge 42 of the stationary inner peripheral surface 41 on the side of the second space 22 . As shown in FIG. 5, among the edges 42 of the stationary-side inner peripheral surface 41 on the side of the second space 22, an oil drainage groove side edge 42A (upper end edge of the oil drainage groove 6) connected to the oil drainage groove 6 is flat. A recessed shape that is recessed toward the first space 21 side in the axial direction of the rotating shaft 11 from a flat surface side edge 42B that is continuous with the surface 43A (the inner peripheral edge that is continuous with the stationary side inner peripheral surface 41 of the flat surface 43A). pointed U-shape).

Lubricating oil that has flowed into the seal gap 20 accumulates below the seal gap 20 . At least part of the lubricating oil accumulated in the lower portion of the seal gap 20 flows down along the oil drain groove 6 and is discharged into the second space 22 .

According to the above configuration, the lubricating oil can be discharged from the bottom of the seal gap 20 by the oil drain groove 6 provided in the stationary side end surface 43 below the axis LA of the rotating shaft 11. It is possible to suppress accumulation of lubricating oil. The seal structure 2 of the turbocharger suppresses the accumulation of lubricating oil in the lower portion of the seal gap 20, so that the lubricating oil is pushed closer to the first space 21 (rotating wheel 12) than the seal member 5 provided in the seal gap 20. is located) can be suppressed.

In some embodiments, as shown in FIG. 1, the supercharger seal structure 2A (2) is designed to flow lubricating oil from the second space 22 to the first space 21A (21) in which the compressor wheel 12A is housed. It is intended to suppress the leakage of The rotary wheel 12 of the supercharger seal structure 2A is composed of the compressor wheel 12A described above. As shown in FIG. 1, the first space 21A and the seal gap 20A (20), which are spaces in which the compressor wheel 12A is accommodated, are arranged in the axial direction of the rotating shaft 11 relative to the second space 22 in which the bearings 13 are accommodated. It is provided on the compressor side.

The rotation-side outer peripheral surface 31A (31) may be, for example, the outer peripheral surface of an annular sleeve 15 included in the supercharger 1 as shown in FIG. The sleeve 15 is attached to the rotating shaft 11 between the compressor wheel 12A (rotating wheel 12) and the bearing 13 in the axial direction of the rotating shaft 11 so as to cover the outer circumference of the rotating shaft 11 . The rotating member 3 may further include a sleeve 15 . The stationary-side inner peripheral surface 41A (41) may be an inner wall surface of the housing 14 facing the outer peripheral surface of the sleeve 15 across the seal gap 20B.

In some embodiments, as shown in FIG. 1, the supercharger seal structure 2B(2) is designed to flow lubricating oil from the second space 22 to the first space 21B(21) in which the turbine wheel 12B is housed. It is intended to suppress the leakage of The rotary wheel 12 of the supercharger seal structure 2B is composed of the above-described turbine wheel 12B. As shown in FIG. 1, the first space 21B and the seal gap 20B (20), which are spaces in which the turbine wheel 12B is accommodated, are arranged in the axial direction of the rotating shaft 11 relative to the second space 22 in which the bearings 13 are accommodated. It is provided on the turbine side.

The rotation-side outer peripheral surface 31B (31) may be, for example, the outer peripheral surface of a boss protruding from the back surface of the turbine wheel 12B as shown in FIG. The stationary-side inner peripheral surface 41B (41) may be an inner wall surface of the housing 14 facing the outer peripheral surface of the boss portion of the turbine wheel 12B across the seal gap 20B. Further, the rotation-side outer peripheral surface 31 may be the outer peripheral surface of the rotating shaft 11 .

The supercharger 1 may include both the supercharger seal structures 2A and 2B. That is, each of the end surface of the stationary inner peripheral surface 41A connected to the turbine side and the end surface of the stationary inner peripheral surface 41B connected to the compressor side may be the stationary side end surface 43 including the oil drain groove 6 described above. .

As shown in FIGS. 3 and 4, the angle position .theta. is defined so that the vertical downward direction with respect to the axis LA of the rotating shaft 11 is 0.degree. and the angle increases in the rotating direction of the rotating shaft 11. In some embodiments, the oil drain groove 6 described above has a pair of groove wall surfaces 62 and 63 facing each other across a gap in the width direction of the oil drain groove 6 . One of the pair of groove wall surfaces 62 and 63 preferably has an upper end 64 that continues to the stationary inner peripheral surface 41 at an angular position θ of +45° or more and +95° or less. The other groove wall surface 63 of the pair of groove wall surfaces 62 and 63 is preferably provided with an upper end 65 that continues to the stationary side inner peripheral surface 41 at an angular position θ in the range of −95° or more and −45° or less.

In the embodiment shown in FIG. 3, the upper end 64 of one groove wall surface 62 is provided at an angular position θ of +45°, and the upper end 65 of the other groove wall surface 63 is provided at an angular position θ of −45°. is provided in

According to the above configuration, the upper end 64 of one groove wall surface 62 is provided in the range of the angular position θ of +45° or more and +95° or less, and the upper end 65 of the other groove wall surface 63 is provided in the range of the angular position θ of −95° or more − By providing the range of 45° or less, it is possible to reduce the inclination angle with respect to the vertical direction at the connection position of the stationary side inner peripheral surface 41 with the one groove wall surface 62 and the other groove wall surface 63, so that the stationary side inner peripheral surface The lubricating oil flowing down along the groove 41 can be guided to the oil drain groove, thereby suppressing accumulation of the lubricating oil on the stationary side inner peripheral surface (41). Further, according to the above configuration, since the length in the width direction of the oil drain groove 6 is large, the lubricating oil is promoted to flow into the oil drain groove 6 from the lower portion of the seal gap 20 .

In the illustrated embodiment, the oil drain groove 6 further has a groove bottom surface 61 that connects the ends of the pair of groove wall surfaces 62 and 63 on the first space 21 side. A groove bottom surface 61 of the oil drain groove 6 is formed so as to include a position where the angular position θ is 0°. By forming the oil drain groove 6 so as to include the position where the angular position θ is 0°, the lubricant can be directly discharged to the oil drain groove 6 from the lower part of the seal gap 20 where the lubricant is accumulated.

As shown in FIG. 4, one groove wall surface 62 described above is more preferably provided with an upper end 64 at a position where the angular position θ is +85° or more and +95° or less. More preferably, the upper end 65 of the other groove wall surface 63 described above is provided at a position where the angular position θ is -95° or more and -85° or less. In the embodiment shown in FIG. 4, the upper end 64 of one groove wall surface 62 is provided at an angular position θ of +90°, and the upper end 65 of the other groove wall surface 63 is provided at an angular position θ of −90°. is provided in

According to the above configuration, the upper end 64 of one groove wall surface 62 is provided in the range of the angular position θ of +85° or more and +95° or less, and the upper end 65 of the other groove wall surface 63 is provided in the range of the angular position θ of −95° or more − By providing the range of 85° or less, it is possible to reduce the angle of inclination with respect to the vertical direction at the connection positions of the stationary side inner peripheral surface 41 with the one groove wall surface 62 and the other groove wall surface 63, so that the stationary side inner peripheral surface Lubricating oil flowing down along the groove 41 can be effectively guided to the oil drain groove 6, and accumulation of the lubricating oil on the stationary side inner peripheral surface 41 can be effectively suppressed.

In some embodiments, as shown in FIG. 4, when the length in the width direction of the oil drain groove 6 is L1 and the diameter of the stationary side inner peripheral surface 41 is L2, the oil drain groove 6 is The condition of 0.95×L2≦L1≦1.05×L2 is satisfied. In the illustrated embodiment, the length L1 in the width direction of the oil drain groove 6 is constant, but in other embodiments, the length in the width direction of the oil drain groove 6 increases toward the bottom. , or may be configured such that the length in the width direction decreases toward the bottom. When the length of the oil drain groove 6 in the width direction is not constant, the length L1 is the length in the width direction of the upper edge of the oil drain groove 6 (the edge connected to the oil drain groove side edge 42A). may be used.

According to the above configuration, by setting the length L1 in the width direction of the oil drain groove 6 to the same length as the diameter L2 of the stationary side inner peripheral surface 41, lubricating oil flows down along the stationary side inner peripheral surface 41. can be effectively guided to the oil drain groove 6, and accumulation of lubricating oil on the stationary side inner peripheral surface 41 can be effectively suppressed. Further, by setting the length L1 of the oil drain groove 6 in the width direction to the same length as the diameter L2 of the stationary side inner peripheral surface 41, the lubricating oil can be discharged well from the oil drain groove 6.

In some embodiments, as shown in FIG. 2 , the above-described groove bottom surface 61 is lower than the edge 32 of the rotation-side outer peripheral surface 31 on the side of the second space 22 below the axis LA of the rotation shaft 11 . It is located on the 1 space 21 side.

According to the above configuration, the groove bottom surface 61 is located below the axis LA of the rotary shaft 11 and closer to the first space 21 than the edge 32 of the rotation-side outer peripheral surface 31 on the second space 22 side. In this case, the lubricating oil flowing down along the rotation-side end surface 33 has a shape that makes it difficult for the lubricating oil to enter the seal gap 20, so that the inflow of the lubricating oil into the seal gap 20 can be suppressed. It is possible to suppress accumulation of lubricating oil.

FIG. 6 is a schematic cross-sectional view showing a cross section along the axis of the seal structure of the supercharger according to one embodiment. FIG. 6 shows a region surrounded by a chain double-dashed line in FIG. In some embodiments, as shown in FIG. 6, the above-described stationary side end surface 43 includes the above-described oil drain groove 6 and a flat surface 43B provided outside the region where the oil drain groove 6 is formed. have. The flat surface 43B extends outward in the radial direction along the radial direction of the rotating shaft 11 from the edge 42 of the stationary-side inner peripheral surface 41 on the side of the second space 22 in the same manner as the flat surface 43A described above. ing. Below the axis LA of the rotary shaft 11 , the flat surface 43B is located closer to the first space 21 than the edge 32 of the rotation-side outer peripheral surface 31 on the second space 22 side. In this case, the lubricating oil flowing down along the rotation-side end surface 33 has a shape that makes it difficult for the lubricating oil to enter the seal gap 20, so that the inflow of the lubricating oil into the seal gap 20 can be suppressed. It is possible to suppress accumulation of lubricating oil.

A projecting member (not shown) may be provided on the stationary-side inner peripheral surface 41 to suppress the inflow of lubricating oil from the second space 22 to the seal gap 20 . The protruding member protrudes radially inward of the rotating shaft 11 from the stationary inner peripheral surface 41 and extends along the circumferential direction of the rotating shaft 11 .

As used herein, expressions such as "in a certain direction", "along a certain direction", "parallel", "perpendicular", "central", "concentric" or "coaxial", etc. express relative or absolute arrangements. represents not only such arrangement strictly, but also the state of being relatively displaced with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
Further, in this specification, expressions representing shapes such as a quadrilateral shape and a cylindrical shape not only represent shapes such as a quadrilateral shape and a cylindrical shape in a geometrically strict sense, but also within the range in which the same effect can be obtained. , a shape including an uneven portion, a chamfered portion, and the like.
Moreover, in this specification, the expressions “comprising”, “including”, or “having” one component are not exclusive expressions excluding the presence of other components.

The present disclosure is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.

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

1) The turbocharger seal structure (2) according to at least one embodiment of the present disclosure is
A seal structure 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) containing said rotating member (3);
a bearing (13) rotatably supporting the rotating shaft (11);
A sealing gap (20) formed between the rotating member (3) and the stationary member (4), the first space (21) accommodating the rotating wheel (12) and the bearing (13). ) and a seal member (5) provided in the seal gap (20) communicating with the second space (22) in which the
The rotating member (3) includes at least a rotating side outer peripheral surface (31) defining the seal gap (20),
The stationary member (4) has a stationary side inner peripheral surface (41) defining the seal gap (20) and an edge (42) of the stationary side inner peripheral surface (41) on the side of the second space (22). a stationary side end face (43) extending along the radial direction of said rotating shaft (11) from
The stationary side end face (43) is an oil drain groove (6) provided in the stationary side end face (43) below the axis (LA) of the rotating shaft (11), and the stationary side inner peripheral surface It has an oil drain groove (6) extending downward along the vertical direction from the edge (42) on the side of the second space (22) at (41).

According to the above configuration 1), lubrication is performed from the bottom of the seal gap (20) by the oil drain groove (6) provided in the stationary side end face (43) below the axis (LA) of the rotating shaft (11). Since the oil can be discharged, it is possible to prevent lubricating oil from accumulating in the lower portion of the seal gap (20). The seal structure (2) for a supercharger described in 1) above suppresses the accumulation of lubricating oil in the lower portion of the seal gap (20), so that the lubricating oil is provided in the seal gap (20). It is possible to suppress leakage to the first space (21) side (the side where the rotating wheel 12 is located) rather than (5).

2) In some embodiments, the supercharger seal structure (6) according to 1) above,
The oil drain groove (6) has a pair of groove wall surfaces (62, 63) facing each other across a gap in the width direction of the oil drain groove (6),
In the case where the angle position (θ) is defined so that the vertical downward direction with respect to the axis (LA) of the rotating shaft (11) is 0° and the angle increases in the rotating direction of the rotating shaft (11) ,
One groove wall surface (62) of the pair of groove wall surfaces (62, 63) has an upper end (64) in the range of the angular position (θ) of +45° or more and +95° or less,
The other groove wall surface (63) of the pair of groove wall surfaces (62, 63) has an upper end (65) in the range of -95° to -45° in the angular position (θ).

According to the above configuration 2), the upper end (64) of one groove wall surface (62) is provided in the range of +45° to +95° in angle position (θ), and the upper end (64) of the other groove wall surface (63) 65) at an angular position (θ) in the range of −95° or more and −45° or less, each of one groove wall surface (62) and the other groove wall surface (63) of the stationary side inner peripheral surface (41) Since the angle of inclination with respect to the vertical direction at the connection position can be reduced, the lubricating oil flowing down along the stationary side inner peripheral surface (41) can be guided to the oil drain groove, thereby It is possible to suppress the accumulation of lubricating oil in the

3) In some embodiments, the supercharger seal structure (2) according to 2) above,
The one groove wall surface (62) is provided with the upper end (64) of the one groove wall surface (62) at a position where the angular position (θ) is +85° or more and +95° or less,
The other groove wall surface (63) is provided with the upper end (65) of the other groove wall surface (63) at a position where the angular position (θ) is -95° or more and -85° or less.

According to the above configuration 3), the upper end (64) of one groove wall surface (62) is provided in the range of +85° or more and +95° or less, and the upper end (65) of the other groove wall surface (63) is provided in the range of -95° to -85° in the angular position (θ). Lubricating oil flowing down along the surface (41) can be effectively guided to the oil drain groove (6), and accumulation of the lubricating oil on the stationary side inner peripheral surface (41) can be effectively suppressed.

4) In some embodiments, the supercharger seal structure (2) according to 3) above,
When the length of the oil drain groove (6) in the width direction is L1, and the diameter of the stationary inner peripheral surface (41) of the stationary member (4) is L2, the oil drain groove (6) satisfies the condition of 0.95×L2≦L1≦1.05×L2.

According to the configuration of 4) above, by setting the length L1 in the width direction of the oil drain groove (6) to the same length as the diameter L2 of the stationary side inner peripheral surface (41), the stationary side inner peripheral surface ( 41) can be effectively guided to the oil drain groove (6), and accumulation of the lubricating oil on the stationary side inner peripheral surface (41) can be effectively suppressed. In addition, by setting the length L1 in the width direction of the oil drain groove (6) to the same length as the diameter L2 of the stationary side inner peripheral surface (41), the lubricating oil discharge performance in the oil drain groove (6) is improved. can be made good.

5) In some embodiments, the supercharger seal structure (2) according to any one of 2) to 4) above,
The oil drain groove (6) further has a groove bottom surface (61) connecting edges of the pair of groove wall surfaces (62, 63) on the first space (21) side,
The bottom surface of the groove (61) is located below the axis (LA) of the rotating shaft (11) and is positioned above the edge (32) on the second space (22) side of the outer peripheral surface (31) on the rotating side. Located on the first space (21) side,
The supercharger seal structure according to any one of claims 2 to 4.

According to the configuration of 5) above, the bottom surface of the groove (61) is located below the axis (LA) of the rotating shaft (11), the edge (32 ) on the first space (21) side. In this case, since the lubricating oil flowing down along the rotation side end surface (33) is difficult to enter the seal gap (20), the lubricating oil can be prevented from flowing into the seal gap (20). It is possible to suppress accumulation of lubricating oil in the lower portion of the seal gap (20).

1 supercharger 2, 2A, 2B seal structure 3 rotating member 4 stationary member 5 sealing member 6 oil drain groove 11 rotating shaft 12 rotating wheel 12A compressor wheel 12B turbine wheel 13 bearing 14 housing 15 sleeves 20, 20A, 20B seal gap 21 , 21A, 21B First space 22 Second space 23 Lubricating oil inlet 24 Lubricating oil supply path 25 Lubricating oil outlet 31, 31A, 31B Rotating side outer peripheral surface 32 Edge 33 Rotating side end surface 41, 41A, 41B Stationary inner periphery Surface 42 Edge 42A Oil drain groove side edge 42B Flat surface side edge Side edge 43 Stationary side end surfaces 43A, 43B Flat surface 44 Lower edge 61 Groove bottom surface 62, 63 Groove wall surface 64, 65 Upper end LA Axis θ Angle position

Claims (5)

A seal structure for a turbocharger,
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 including 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 providing communication between a first space in which the rotating wheel is accommodated and a second space in which the bearing is accommodated. a sealing member;
The rotating member includes at least a rotating-side outer peripheral surface that defines the seal gap,
The stationary member includes a stationary-side inner peripheral surface that defines the seal gap, a stationary-side end surface that extends along the radial direction of the rotating shaft from an edge of the stationary-side inner peripheral surface on the second space side, including
The stationary member is an oil drain groove provided in the stationary side end surface below the axis of the rotating shaft, and extends vertically downward from the edge of the stationary side inner peripheral surface on the second space side. having an oil drain groove extending towards
The seal structure of the supercharger. The oil drain groove has a pair of groove wall surfaces facing each other across a gap in the width direction of the oil drain groove,
In the case where the angular position is defined such that the vertical downward direction with respect to the axis line of the rotating shaft is 0° and the angle increases in the rotating direction of the rotating shaft,
one of the pair of groove wall surfaces has an upper end in the range of the angular position of +45° or more and +95° or less;
The other of the pair of groove wall surfaces has an upper end in the range of the angular position of -95° or more and -45° or less.
A seal structure for a supercharger according to claim 1. The one groove wall surface is provided with the upper end of the one groove wall surface at a position where the angular position is +85° or more and +95° or less,
The other groove wall surface is provided with the upper end of the other groove wall surface at a position where the angular position is −95° or more and −85° or less.
The seal structure for a supercharger according to claim 2. When the length of the oil drain groove in the width direction is L1, and the diameter of the stationary side inner peripheral surface of the stationary member is L2, the oil drain groove satisfies the following conditions: 0.95×L2≦L1≦1. Satisfying the condition of 05 × L2,
The sealing structure for a supercharger according to claim 3. The oil drain groove further has a groove bottom surface connecting edges of the pair of groove wall surfaces on the first space side,
The bottom surface of the groove is located below the axis of the rotating shaft and closer to the first space than the edge of the rotating-side outer peripheral surface on the second space side,
The supercharger seal structure according to any one of claims 2 to 4.

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