JP7297534B2 - rotary machine - Google Patents

Description

The present invention relates to rotary machines.

For example, a rotating machine such as a centrifugal compressor, a centrifugal pump, a generator, or a turbine includes a rotor as a rotating body that rotates about its axis, and a casing as a stationary body that covers the rotor from the outside. Frictional resistance (disc friction loss) occurs through the working fluid between the rotating rotor and the stationary casing. In particular, in the case of a centrifugal compressor, it is known that the disk friction loss increases because the outer diameter of the impeller is increased in order to obtain a high head with respect to the discharge flow rate.

As a technique for reducing such disc friction loss, the one described in Patent Document 1 below is known. In Patent Document 1, a plurality of fences are provided on the back side of an impeller of a centrifugal compressor at intervals in the radial direction, thereby dividing the space on the back side into a plurality of sections. It is said that this controls the velocity distribution in each space and reduces the disc friction loss.

JP-A-3-11198

However, in the device described in Patent Document 1, the fluid flowing through the divided space contacts the inner surface of the casing, which is a stationary body. Therefore, there are friction losses between the impeller back surface and the casing. That is, the device described in Patent Document 1 still has room for improvement.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a rotary machine with improved efficiency by further reducing friction loss.

A rotating machine according to an aspect of the present invention is rotatable around an axis, and has a first opposing surface that extends in a plane that intersects the axis, and an outer peripheral surface that faces radially outward with respect to the axis. Between the body, a second opposing surface facing the first opposing surface in the axial direction and forming a flow path through which fluid flows between the body and the first opposing surface, and the outer peripheral surface a stationary body having an inner peripheral surface that forms an outer flow path that communicates with the passage; and a stationary body that is provided at both ends of the outer peripheral surface in the axial direction, protrudes toward the inner peripheral surface , and has a gap with respect to the inner peripheral surface. forming a vortex in a fluid flowing into the cavity through the gap while the rotating body is rotating ; and a pair of ring portions that moderate the circumferential velocity gradient of the fluid in the.

According to the above configuration, when the fluid flows into the outer channel formed between the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body, it collides with one of the ring portions. After that, the fluid flows around the ring portion into the cavity. Fluid entering the cavity forms a vortex. Due to the velocity component in the circumferential direction of this vortex, the velocity difference between the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body is reduced (the velocity gradient is moderated). As a result, friction loss occurring between the rotating body and the stationary body can be reduced. On the other hand, if the ring portion is not provided, a vortex is not formed, so friction loss occurs between the outer peripheral surface and the inner peripheral surface due to the velocity gradient. According to the above configuration, it is possible to reduce the possibility of such friction loss.

In the above rotary machine, the fluid may flow from the radially inner side to the outer side in the flow path.

According to the above configuration, the fluid that has flowed from the radially inner side to the outer side in the flow path collides with the ring portion on the side of the flow path when flowing into the outer flow path, thereby circulating around the ring portion. It flows into the cavity as if it were crawling. Fluid entering the cavity forms a vortex. As a result, friction loss occurring between the rotating body and the stationary body can be reduced.

In the rotating machine described above, the fluid may flow radially inward from the outer side in the flow path.

According to the above configuration, the fluid flowing axially in the outer flow path toward the flow path collides with the ring portion on the opposite side of the flow path, so that the fluid flows around the ring portion and enters the cavity. influx. Fluid entering the cavity forms a vortex. As a result, friction loss occurring between the rotating body and the stationary body can be reduced.

A rotating machine according to an aspect of the present invention is rotatable around an axis, and has a first opposing surface that extends in a plane that intersects the axis, and an outer peripheral surface that faces radially outward with respect to the axis. a body, a second opposing surface facing the first opposing surface in the axial direction and forming a flow path between the body and the first opposing surface through which fluid flows radially inwardly and outwardly; a stationary body having an inner peripheral surface that forms an outer flow path that communicates with the flow path between itself and the outer peripheral surface; and the inner peripheral surface with a gap therebetween to define a cavity that forms a vortex with the outer peripheral surface, and in a state in which the rotating body is rotating, it enters the cavity through the gap a ring portion that forms a vortex in the inflowing fluid and moderates the circumferential velocity gradient of the fluid between the outer peripheral surface and the inner peripheral surface.

According to the above configuration, the fluid that has flowed from the radially inner side to the outer side in the flow path collides with the ring portion on the side of the flow path when flowing into the outer flow path, thereby circulating around the ring portion. It flows into the cavity as if it were crawling. Fluid entering the cavity forms a vortex. As a result, friction loss occurring between the rotating body and the stationary body can be reduced.

A rotating machine according to an aspect of the present invention is rotatable around an axis, and has a first opposing surface that extends in a plane that intersects the axis, and an outer peripheral surface that faces radially outward with respect to the axis. a body, a second opposing surface facing the first opposing surface in the axial direction and forming a flow path between the body and the first opposing surface through which fluid flows radially inward from the outer side; A stationary body having an inner peripheral surface that forms an outer flow path that communicates with the flow path between itself and the outer peripheral surface; It protrudes toward the inner peripheral surface and faces the inner peripheral surface with a gap to define a cavity that forms a vortex with the outer peripheral surface, and the rotating body rotates through the gap. a ring portion that forms a vortex in the fluid that flows into the cavity and moderates a circumferential velocity gradient of the fluid between the outer peripheral surface and the inner peripheral surface.

According to the above configuration, the fluid flowing axially in the outer flow path toward the flow path collides with the ring portion on the opposite side of the flow path, so that the fluid flows around the ring portion and enters the cavity. influx. Fluid entering the cavity forms a vortex. As a result, friction loss occurring between the rotating body and the stationary body can be reduced.

The rotating machine may further include a curved surface portion that connects the ring portion and the outer peripheral surface in a curved shape.

According to the above configuration, since the ring portion and the outer peripheral surface are connected by the curved surface portion, a dead water region is less likely to be formed in the cavity. As a result, the vortex formed in the cavity can be held more stably.

According to the present invention, it is possible to provide a rotating machine with improved efficiency by further reducing friction loss.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structure of the centrifugal compressor as a rotary machine which concerns on 1st embodiment of this invention. 2 is an enlarged cross-sectional view showing the configuration around the impeller of the centrifugal compressor according to the first embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a principal part expanded sectional view of the centrifugal compressor which concerns on 1st embodiment of this invention. It is a principal part expanded sectional view which shows the modification of the centrifugal compressor which concerns on 1st embodiment of this invention. It is a principal part expanded sectional view which shows the further modification of the centrifugal compressor which concerns on 1st embodiment of this invention. It is a principal part expanded sectional view of the centrifugal compressor which concerns on 2nd embodiment of this invention. It is a principal part expanded sectional view which shows the modification of the centrifugal compressor based on 2nd embodiment of this invention. It is a principal part expanded sectional view of the centrifugal compressor based on 3rd embodiment of this invention. It is a principal part expanded sectional view which shows the modification of the centrifugal compressor based on 3rd embodiment of this invention.

[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. In this embodiment, a multi-stage centrifugal compressor as a rotary machine will be described as an example. It is also possible to apply the configuration of the present embodiment to a single-stage centrifugal compressor, centrifugal pump, generator, or turbine as the rotary machine.

The centrifugal compressor 100 includes a rotating shaft 1 that rotates about its axis, a casing 3 as a stationary body S that forms a fluid flow path 2 by covering the rotating shaft 1, and a rotating shaft provided on the rotating shaft 1. a plurality of impellers 4 as bodies R;

The casing 3 has a cylindrical shape extending along the axis O. As shown in FIG. The rotary shaft 1 extends through the casing 3 along the axis O. As shown in FIG. A journal bearing 5 and a thrust bearing 6 are provided at both ends of the casing 3 in the direction of the axis O, respectively. The rotary shaft 1 is rotatably supported around the axis O by these journal bearings 5 and thrust bearings 6 .

An intake port 7 for taking in air as the working fluid G from the outside is provided on one side of the casing 3 in the direction of the axis O. As shown in FIG. Furthermore, an exhaust port 8 through which the working fluid G compressed inside the casing 3 is exhausted is provided on the other side of the casing 3 in the direction of the axis O. As shown in FIG.

Inside the casing 3, an internal space is formed that communicates with the intake port 7 and the exhaust port 8, and repeats contraction and expansion in diameter. This internal space accommodates a plurality of impellers 4 and forms part of the fluid flow path 2 described above. In the following description, the side of the fluid flow path 2 where the intake port 7 is located is called the upstream side, and the side where the exhaust port 8 is located is called the downstream side.

A plurality of (six) impellers 4 are provided on the outer peripheral surface of the rotating shaft 1 at intervals in the direction of the axis O. As shown in FIG. As shown in FIG. 2, each impeller 4 includes a disk 41 having a substantially circular cross section when viewed from the direction of the axis O, a plurality of blades 42 provided on the upstream side surface of the disk 41, and these plurality of blades. and a cover 43 that covers 42 from the upstream side.

The disk 41 is formed so that its radial dimension gradually increases from one side to the other side in the direction of the axis O when viewed from the direction intersecting the axis O, so that the disk 41 has a generally conical shape. there is

A plurality of blades 42 are arranged radially outward in the radial direction about the axis O on conical surfaces facing the upstream side of both surfaces of the disk 41 in the direction of the axis O. As shown in FIG. More specifically, these blades are formed of thin plates erected from the upstream surface of the disk 41 toward the upstream side. When viewed from the direction of the axis O, the plurality of blades 42 are curved from one side to the other side in the circumferential direction.

A cover 43 is provided on the edge of the upstream side of the blade 42 . In other words, the plurality of blades 42 are sandwiched between the cover 43 and the disc 41 in the direction of the axis O. As shown in FIG. Thereby, a space is formed between the cover 43, the disk 41, and the pair of blades 42 adjacent to each other. This space forms a part (compression flow path 22) of the fluid flow path 2, which will be described later.

The fluid flow path 2 is a space that communicates the impeller 4 configured as described above and the internal space of the casing 3 . In this embodiment, one fluid flow path 2 is formed for each impeller 4 (for each compression stage). That is, in the centrifugal compressor 100, five fluid passages 2 are formed continuously from the upstream side to the downstream side, corresponding to the five impellers 4 excluding the impeller 4 at the last stage.

Each fluid channel 2 has a suction channel 21 , a compression channel 22 , a diffuser channel 23 , a return bend 24 and a guide channel 25 . Note that FIG. 2 shows only one stage impeller 4 out of the fluid flow path 2 and the impeller 4 .

In the impeller 4 of the first stage, the suction passage 21 is directly connected to the intake port 7 described above. External air is taken in as working fluid G into each channel on the fluid channel 2 by the suction channel 21 . More specifically, the suction flow path 21 is gradually curved radially outward from the direction of the axis O as it goes from the upstream side to the downstream side.

The suction channel 21 in the impeller 4 of the second and subsequent stages communicates with the downstream end of a guide channel 25 (described later) in the fluid channel 2 of the previous stage (first stage). That is, the flow direction of the working fluid G that has passed through the guide channel 25 is changed so as to face the downstream side along the axis O in the same manner as described above.

The compression channel 22 is a channel surrounded by the upstream surface of the disk 41, the downstream surface of the cover 43, and a pair of blades 42 adjacent in the circumferential direction. More specifically, the cross-sectional area of the compression channel 22 gradually decreases from the radially inner side toward the outer side. As a result, the working fluid G flowing through the compression passage 22 while the impeller 4 is rotating is gradually compressed into a high-pressure fluid.

The diffuser flow path 23 is a flow path that extends from the radially inner side of the axis O toward the outer side. The radially inner end of the diffuser channel 23 communicates with the radially outer end of the compression channel 22 .

The return bend portion 24 reverses the flow direction of the working fluid G that has flowed from the radially inner side to the outer side through the diffuser flow path 23 toward the radially inner side. One end side (upstream side) of the return bend portion 24 communicates with the diffuser flow path 23 , and the other end side (downstream side) thereof communicates with the guide flow path 25 . In the middle of the return bend portion 24, the radially outermost portion is the top portion.

The guide channel 25 extends radially inward from the downstream end of the return bend portion 24 . A radially outer end portion of the guide channel 25 communicates with the return bend portion 24 described above. The radially inner end of the guide channel 25 communicates with the suction channel 21 in the subsequent fluid channel 2 as described above.

In the centrifugal compressor 100 configured as described above, a gap is formed between the casing 3 and the impeller 4 in order to realize smooth rotation of the impeller 4 . More specifically, a gap is formed between the disk rear surface 41A (first facing surface P1) facing the downstream side of the disk 41 and the casing rear surface 3A (second facing surface P2) facing the disk rear surface 41A. It is This gap is the flow path F1. In the flow path F1, as indicated by an arrow A in FIG. 2, the high-pressure fluid leaking from the compression flow path 22 on the rear side flows from the inside to the outside in the radial direction.

Furthermore, there is a gap between the cover upstream surface 43B (first facing surface P1′) facing the upstream side of the cover 43 and the casing upstream surface 3B (second facing surface P2′) facing the cover upstream surface 43B. formed. This gap is defined as a flow path F2. In the flow path F2, as indicated by an arrow B in FIG. 2, a high-pressure fluid flowing through the diffuser flow path 23 flows from the radially outer side toward the inner side.

In addition, there is also a gap between the radially outwardly facing disk outer peripheral surface 41C of the disk 41, the radially outwardly facing cover outer peripheral surface 43C of the cover 43, and the casing inner peripheral surface 3D, which is the inner peripheral surface of the casing 3. is formed. This gap is a channel F3 (outer channel). Channel F3 communicates with channel F1 and channel F2.

Here, between the impeller 4 as the rotating body R and the casing 3 as the stationary body S, frictional resistance (disc friction loss) occurs via the fluid flowing through the flow paths F1 and F2. occur. In particular, in the case of the centrifugal compressor 100, it is known that the disc friction loss increases as the lift increases because the outer diameter of the impeller 4 increases. In addition, since the circumferential velocity of the fluid is the highest on the outer peripheral surface of the impeller 4 (the disk outer peripheral surface 41C and the cover outer peripheral surface 43C), the friction loss generated between these outer peripheral surfaces and the casing inner peripheral surface 3D is also need to be reduced.

Therefore, in this embodiment, as shown in FIGS. 3 and 4, ring portions 60 and 60' projecting radially outward are provided on the disk outer peripheral surface 41C and the cover outer peripheral surface 43C, respectively. As shown in FIG. 3, the disk outer peripheral surface 41C is provided with a pair of ring portions 60 protruding into the flow path F3 toward the casing inner peripheral surface 3D at both edges in the direction of the axis O. As shown in FIG. The pair of ring portions 60 form an annular shape that is continuous in the circumferential direction. The ring portion 60 on the flow path F1 side is a first ring portion 61 , and the ring portion 60 on the side away from the flow path F1 is a second ring portion 62 . In this embodiment, the first ring portion 61 and the second ring portion 62 and the disk outer peripheral surface 41C are orthogonal to each other. A space extending in the direction of the axis O is formed between the first ring portion 61 and the second ring portion 62 . This space is called a cavity C.

Further, as shown in FIG. 4, the outer peripheral surface 43C of the cover is provided with a pair of ring portions 60' protruding into the flow path F3 toward the inner peripheral surface 3D of the casing at the edges on both sides in the direction of the axis O. there is These pair of ring portions 60' form an annular shape that is continuous in the circumferential direction. The ring portion 60' on the flow path F2 side is a first ring portion 61', and the ring portion 60' on the side away from the flow path F2 is a second ring portion 62'. In this embodiment, the first ring portion 61' and the second ring portion 62' and the cover outer peripheral surface 43C are orthogonal to each other. A space extending in the direction of the axis O is formed between the first ring portion 61' and the second ring portion 62'. This space is defined as a cavity C'.

According to the above configuration, when the fluid flows into the flow path F3, it collides with the ring portions 60 and 60', so that the fluid flows around the ring portions and into the cavities C and C'. The fluid that has flowed into the cavities C, C' forms a vortex. Due to the circumferential velocity component of this vortex, the outer peripheral surface of the impeller 4 as the rotating body R (disk outer peripheral surface 41C and cover outer peripheral surface 43C) and the inner peripheral surface of the stationary body S (casing inner peripheral surface 3D) The velocity difference between the fluids becomes smaller (the velocity gradient becomes gentler). As a result, friction loss occurring between the rotating body R and the stationary body S can be reduced. On the other hand, if the ring portion is not provided, a vortex will not be formed, so there will be no friction between the outer peripheral surface (disk outer peripheral surface 41C and bar outer peripheral surface 43C) and the inner peripheral surface (casing inner peripheral surface 3D). Friction loss based on the velocity gradient occurs. According to the above configuration, it is possible to reduce the possibility of such friction loss. Thereby, the efficiency of the centrifugal compressor 100 can be further improved.

In particular, according to the above configuration, when the fluid that has flowed from the radially inner side to the outer side in the flow path F1 flows into the flow path F3, the ring portion 60 (the first ring portion 61) on the flow path F1 side By colliding with , it flows into the cavity C while going around the first ring portion 61 . The fluid flowing into cavity C forms a vortex. As a result, friction loss occurring between the rotating body R and the stationary body S can be reduced.

Further, according to the above configuration, the fluid flowing in the direction of the axis O in the flow path F3 toward the flow path F2 collides with the ring portion 60' (second ring portion 62') on the opposite side of the flow path F2. As a result, the liquid flows around the second ring portion 62' and into the cavity C'. The fluid that has flowed into cavity C' forms a vortex. The velocity component in the circumferential direction of this vortex reduces the velocity difference of the fluid between the outer peripheral surface of the rotating body R and the inner peripheral surface of the stationary body S (the velocity gradient becomes gentle). As a result, friction loss occurring between the rotating body and the stationary body can be reduced.

Thus, in this embodiment, the above-described ring portions 60 and 60' are provided on the disk outer peripheral surface 41C and the cover outer peripheral surface 43C, respectively. As a result, the friction loss between the outer peripheral end surface of the impeller 4 and the casing inner peripheral surface 3D can be further reduced.

The first embodiment of the present invention has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present invention. For example, in the first embodiment, the disk outer peripheral surface 41C, the cover outer peripheral surface 43C, and the ring portions 60, 60' are orthogonal to each other. However, it is also possible to configure the part as shown in FIG. In the example of FIG. 5, the disk outer peripheral surface 41C, the cover outer peripheral surface 43C, and the ring portions 60, 60' are connected by curved surface portions S that are curved. In other words, no corners are formed inside the cavity C in this configuration. As a result, dead water regions (regions where fluid stays) are less likely to be formed in the cavities C and C'. As a result, the vortices formed in the cavities C and C' can be held more stably.

[Second embodiment]
Next, a second embodiment of the invention will be described with reference to FIG. In addition, the same code|symbol is attached|subjected about the structure similar to said 1st embodiment, and detailed description is abbreviate|omitted. As shown in FIG. 6, in this embodiment, a ring portion 60B similar to that described in the first embodiment is provided only at the edge of the disk outer peripheral surface 41C on the flow path F1 side. A space defined between the ring portion 60B and the disk outer peripheral surface 41C is a cavity C'.

According to the above configuration, the fluid that has flowed from the radially inner side to the outer side in the flow path F1 collides with the ring portion 60B when flowing into the flow path F3, and rotates around the ring portion 60B. It flows into the cavity C' in such a way as to be squeezed. The fluid that has flowed into cavity C' forms a vortex. As a result, friction loss occurring between the rotating body R and the stationary body S can be reduced. Thereby, the efficiency of the centrifugal compressor 100 can be further improved. In addition, since only one ring portion 60B is provided in this embodiment, it is possible to reduce the number of parts and manufacturing man-hours compared to a configuration including a plurality of ring portions 60B, for example.

The second embodiment of the present invention has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present invention. For example, as shown in FIG. 7, a curved surface portion S' may be provided between the disk outer peripheral surface 41C and the ring portion 60B to connect them in a curved shape. According to this configuration, a dead water region (a region where fluid stays) is less likely to be formed in the cavity C'. As a result, the vortex formed in the cavity C' can be held more stably.

[Third Embodiment]
Next, a third embodiment of the invention will be described with reference to FIG. In addition, the same code|symbol is attached|subjected about the structure similar to said each embodiment, and detailed description is abbreviate|omitted. As shown in FIG. 8, in the present embodiment, a ring portion 60C similar to that described in the first embodiment is provided only on the edge of the cover outer peripheral surface 43C on the flow path F2 side. A space defined between the ring portion 60C and the outer peripheral surface 43C of the cover is a cavity C''.

According to the above configuration, the fluid flowing in the direction of the axis O in the flow path F3 toward the flow path F2 collides with the ring portion 60C provided at the edge on the opposite side of the flow path F2. It flows into the cavity C'' by going around the periphery of the portion 60C. Fluid entering the cavity C'' forms a vortex. As a result, friction loss occurring between the rotating body R and the stationary body S can be reduced. In addition, since only one ring portion 60C is provided in this embodiment, it is possible to reduce the number of parts and manufacturing man-hours compared to a configuration including a plurality of ring portions 60C.

The third embodiment of the present invention has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present invention. For example, as shown in FIG. 9, a curved surface portion S'' may be provided between the cover outer peripheral surface 43C and the ring portion 60C to connect them in a curved surface shape. According to this configuration, a dead water region (a region where fluid stays) is less likely to be formed in the cavity C''. As a result, the vortex formed in the cavity C'' can be held more stably.

100 centrifugal compressor (rotating machine)
1 Rotary shaft 2 Fluid flow path 3 Casing 3A Casing back surface 3B Casing upstream surface 3D Casing inner peripheral surface 4 Impeller 5 Journal bearing 6 Thrust bearing 7 Intake port 8 Exhaust port 10 Concave portion 11 Stationary side concave portion 21 Suction channel 22 Compression channel 23 Diffuser channel 24 Return bend part 25 Guide channel 41 Disk 41A Disk back surface 41C Disk outer peripheral surface 42 Blade 43 Cover 43B Cover upstream surface 43C Cover outer peripheral surface 50 Return vanes 60, 60B, 60C Ring parts 61, 61' First ring part 62, 62' Second ring portions C, C', C'' Cavities F1, F2, F3 Flow path O Axis P1 First opposing surface P2 Second opposing surface R Rotating body S Stationary body

Claims (6)

a rotating body rotatable about an axis and having a first opposing surface extending in a plane intersecting the axis and an outer peripheral surface facing radially outward with respect to the axis;
A second opposing surface that faces the first opposing surface in the axial direction and forms a flow path between the first opposing surface and the first opposing surface, and a space between the second opposing surface and the outer peripheral surface that communicates with the flow path a stationary body having an inner peripheral surface forming an outer flow path for
Provided at both ends of the outer peripheral surface in the axial direction, protrude toward the inner peripheral surface and face the inner peripheral surface with a gap to define a cavity, in which the rotating body rotates. a pair of ring portions for forming a vortex in the fluid flowing into the cavity through the gap in a state where the fluid is in the closed state , thereby reducing a circumferential velocity gradient of the fluid between the outer peripheral surface and the inner peripheral surface;
A rotary machine with The rotary machine according to claim 1, wherein the fluid flows radially inwardly outward in the flow path. The rotary machine according to claim 1, wherein the fluid flows radially inward from the outer side in the flow path. a rotating body rotatable about an axis and having a first opposing surface extending in a plane intersecting the axis and an outer peripheral surface facing radially outward with respect to the axis;
a second opposing surface facing the first opposing surface in the axial direction and forming a flow path between the first opposing surface and the first opposing surface through which fluid flows from the radially inner side to the outer side, and the outer peripheral surface; a stationary body having an inner peripheral surface forming an outer flow path communicating with the flow path between;
Provided at the edge of the flow path side of the outer peripheral surface, protrudes toward the inner peripheral surface and faces the inner peripheral surface with a gap , thereby forming a vortex with the outer peripheral surface. defining a cavity, forming a vortex in a fluid flowing into the cavity through the gap while the rotating body is rotating , and causing a circumferential velocity gradient of the fluid between the outer peripheral surface and the inner peripheral surface; a ring portion that moderates the
A rotary machine with a rotating body rotatable about an axis and having a first opposing surface extending in a plane intersecting the axis and an outer peripheral surface facing radially outward with respect to the axis;
A second opposing surface facing the first opposing surface in the axial direction and forming a flow path between the first opposing surface and the first opposing surface through which fluid flows from the radially outer side to the inner side; and the outer peripheral surface. a stationary body having an inner peripheral surface forming an outer flow path communicating with the flow path between;
Provided on the edge of the outer peripheral surface opposite to the flow path, projecting toward the inner peripheral surface and facing the inner peripheral surface with a gap between the outer peripheral surface and the A cavity forming a vortex is defined, and a vortex is formed in the fluid flowing into the cavity through the gap while the rotating body is rotating , so that the fluid flows between the outer peripheral surface and the inner peripheral surface. a ring portion that moderates the circumferential velocity gradient;
A rotary machine with The rotary machine according to any one of claims 1 to 5, further comprising a curved surface portion connecting said ring portion and said outer peripheral surface.

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