JP2015031179A - Rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary machine capable of reducing loss due to secondary flows without giving influences to a main flow.SOLUTION: The rotary machine includes a plurality of blades 19 arranged at spaces in the peripheral direction while extending from an axis O as a center in the radial direction, and two faces provided on both sides in the axial direction of the blades 19 for defining flow paths where fluid F flows in the radial direction, together with the pair of neighboring blades 19, respectively. On each of the two faces, a step part is formed to disturb the flow of the fluid flowing in the flow path.

Description

  The present invention relates to a rotating machine.

  A turbo machine such as a centrifugal pump that gives energy to a fluid has an impeller provided inside the casing so as to be relatively rotatable with the casing, and the impeller rotates the fluid taken in from the outside of the casing. The pressure is increased outward in the radial direction of the flow path in the impeller and discharged.

  When energy is applied to the fluid, a secondary flow is generated in the flow path of the impeller used in the centrifugal pump, which is affected by various influences such as centrifugal force and Coriolis force of the impeller and hinders the main flow. This secondary flow is one of the factors that cause loss of power and reduce the performance of the rotating machine. As a method for reducing the secondary flow, for example, there is a structure in which a flow is shielded by placing a shielding object in the flow direction.

  As a technique for shielding a flow, for example, Patent Document 1 discloses a structure in which a protrusion is formed on an outer peripheral portion of a rotating substrate of a rotating impeller so as to block the flow in a spiral pump that is a gas-liquid mixing pump that generates microbubbles. Is disclosed. In such a spiral pump, by providing protrusions in the flow path, the flow is blocked and the liquid, which is a fluid, collides and disturbs, so that bubbles contained in the liquid can be made fine.

JP 2009-034578 A

  However, in the structure disclosed in Patent Document 1, when it is used for a rotary machine such as a turbo machine, it affects not only the secondary flow but also the main flow that sends out the pressurized fluid. Specifically, the friction loss increases due to an increase in the number of portions in contact with the mainstream. Therefore, the loss with respect to the main flow must also be considered, and there is a problem that only the secondary flow cannot be easily reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a rotating machine capable of reducing a loss due to a secondary flow without affecting the mainstream.

In order to solve the above problems, the present invention proposes the following means.
A rotating machine according to an aspect of the present invention includes a plurality of blades that extend in the radial direction about an axis and are arranged on both sides in the axial direction of the blades. A pair of adjacent blades that define a flow path through which fluid flows in the radial direction, and each of the two faces has a step portion that disturbs the flow of fluid flowing through the flow path. It is formed.

  According to such a rotating machine, by providing the step portions so as to disturb the flow of the fluid flowing through the flow channel from the two surfaces that define the flow channel, along the two surfaces that define the flow channel. Can disrupt the secondary flow. On the other hand, the step portion is formed from two surfaces that define the flow path, so that a space for fluid to flow between the two surfaces that define the flow path together with the blades can be secured. It does not block the main flow that flows from the inside to the outside in the radial direction. Therefore, it is possible to flow the main flow with little influence while weakening the secondary flow by disturbing the flow and reducing the speed of the secondary flow. Thereby, it is possible to efficiently reduce the loss due to the secondary flow without affecting the main flow.

  Further, in the rotating machine according to another aspect of the present invention, at least one of the stepped portions protrudes from the surface and is spaced from the surface facing the circumferential direction of the pair of blades in the circumferential direction. It extends from the inner side in the direction toward the outer side in the radial direction.

  According to such a rotating machine, at least one of the stepped portions protrudes from the radially inner side to the radially outer side at a position spaced in the circumferential direction from the circumferentially opposed surfaces of the pair of blades. Thus, the secondary flow that is pushed out to the surface facing the circumferential direction of the pair of blades and flows in the direction intersecting the surface facing the circumferential direction of the pair of blades can be blocked. That is, the secondary flow that flows along the two surfaces that define the flow path can be made to collide with the protruding stepped portion, and the flow can be easily disturbed. This makes it easy to efficiently reduce the loss due to the secondary flow without affecting the main flow.

  Furthermore, in the rotating machine according to another aspect of the present invention, at least one of the stepped portions is recessed from the surface, and has a diameter separated from a surface facing the circumferential direction in the pair of blades. It extends from the inner side in the direction toward the outer side in the radial direction.

  According to such a rotary machine, at least one of the stepped portions extends from the inner side in the radial direction toward the outer side in the radial direction at a position spaced apart from the circumferentially facing surfaces of the pair of blades and is recessed. Thus, the secondary flow that is pushed out to the surfaces facing the circumferential direction of the pair of blades and flows in the direction intersecting the surfaces facing the circumferential direction of the pair of blades can flow into the stepped portion. That is, the secondary flow flowing along the two surfaces defining the flow path can be caused to flow into the recessed step portion, and the flow of the secondary flow can be easily disturbed. This makes it easy to efficiently reduce the loss due to the secondary flow without affecting the main flow.

  The rotating machine according to an aspect of the present invention is provided on each of the blades extending in the radial direction about the axis and arranged in a plurality in a circumferential direction at both sides in the axial direction of the blade. And two surfaces defining a flow path through which fluid flows in the radial direction together with a pair of adjacent blades, the flow of fluid flowing through the flow path on one of the two surfaces Projecting from the surface so as to disturb the surface, and a convex portion extending from the radially inner side to the radially outer side is formed at a position spaced apart from the circumferentially facing surface of the pair of blades, and the convex portion The protrusion height from the surface is ¼ or less of the distance between the two surfaces.

  According to such a rotating machine, the convex portion on one of the two surfaces is spaced from the circumferentially opposed surfaces of the pair of blades in the circumferential direction, from the radially inner side toward the radially outer side. By extending and projecting, the secondary flow that is pushed out to the circumferentially opposed surface of the pair of blades and flows in the direction intersecting the circumferentially opposed surface of the pair of blades can be blocked. And since the protrusion height of a convex part is 1/4 or less with respect to the distance between the two surfaces which define a flow path, since a flow path is not obstruct | occluded, it flows through the flow path. Does not block the mainstream. For this reason, the main flow can be made to flow with little influence while easily disturbing the flow by causing the secondary flow flowing along the surface to collide with the convex portion. Thereby, it is possible to efficiently reduce the loss due to the secondary flow without affecting the main flow.

  Furthermore, the rotating machine according to one aspect of the present invention is provided on each of the blades extending in the radial direction around the axis and spaced apart in the circumferential direction, and on both sides of the blade in the axial direction. And two surfaces defining a flow path through which fluid flows in the radial direction together with a pair of adjacent blades, the flow of fluid flowing through the flow path on one of the two surfaces A concave portion extending from the inner side in the radial direction toward the outer side in the radial direction is formed at a position that is recessed from the surface so as to disturb the circumferential direction and is spaced apart from the circumferentially facing surface of the pair of blades. And

  According to such a rotating machine, the concave portion on one of the two surfaces extends from the radially inner side toward the radially outer side at a position spaced in the circumferential direction from the circumferentially opposed surfaces of the pair of blades. By being recessed, the secondary flow that is pushed out to the surfaces facing the circumferential direction of the pair of blades and flows in the direction intersecting the surfaces facing the circumferential direction of the pair of blades can flow. Therefore, one of the secondary flows flowing along the two surfaces defining the flow path can be caused to flow into the recess, and the flow of the secondary flow can be easily disturbed. Moreover, the main flow which flows in the flow path is not obstructed by not providing it so as to protrude into the flow path. Therefore, the main flow can be made to flow without being affected while the secondary flow F2 is weakened by disturbing the flow and reducing the speed of the secondary flow. Thereby, it is possible to efficiently reduce the loss due to the secondary flow without affecting the main flow.

  According to the rotating machine of the present invention, the loss due to the secondary flow is reduced without affecting the main flow by providing a step portion that disturbs the flow while securing a space between the two surfaces that define the flow path. It is an object of the present invention to provide a rotating machine that can be used.

1 is an overall sectional view of a centrifugal pump according to a first embodiment of the present invention. It is principal part sectional drawing which shows the centrifugal pump which concerns on 1st embodiment of this invention. It is a figure showing the whole impeller concerning a first embodiment of the present invention. It is a figure which shows the cross section of the flow path of the impeller which concerns on 1st embodiment of this invention. It is a figure which shows the whole impeller which concerns on 2nd embodiment of this invention. It is a figure which shows the cross section of the flow path of the impeller which concerns on 2nd embodiment of this invention. It is a figure which shows the whole impeller which concerns on 3rd embodiment of this invention. It is a figure which shows the cross section of the flow path of the impeller which concerns on 3rd embodiment of this invention. It is a figure which shows the whole impeller which concerns on 4th embodiment of this invention. It is a figure which shows the cross section of the flow path of the impeller which concerns on 4th embodiment of this invention. It is a figure which shows the whole impeller which concerns on the 1st modification of this invention. It is a figure which shows the cross section of the flow path of the impeller which concerns on the 1st modification of this invention.

Hereinafter, a rotary machine according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.
The rotary machine in 1st embodiment is the centrifugal pump (rotary machine) 1 which is a turbo machine, for example, a water supply pump is mentioned, In this embodiment, it is a multistage pump. As shown in FIG. 1, the centrifugal pump (rotary machine) 1 passes through the outer casing 2, the inner casing 3 (casing) disposed inside the outer casing 2, and the inner casing 3. The rotary shaft 4 that extends around the arranged axis O, and a suction impeller 5 and a plurality of impellers 6 (impellers) that are integrally fixed to the rotary shaft 4 via a key are mainly provided. ing.

  The outer casing 2 has a hollow shape, and is formed with a suction port 8 that sucks the fluid F toward the radially inner side and a discharge port 9 that discharges the fluid F toward the radially outer side.

  A casing cover 11 is attached to one end portion (left end portion in FIG. 1) of the outer casing 2, and a casing cover 12 is attached to the other end portion of the outer casing 2. The casing covers 11 and 12 are fixed by a plurality of fastening bolts 13 and 14, respectively, so that the outer casing 2, the inner casing 3, and the casing covers 11 and 12 are integrated. A condensate recovery line (not shown) is connected to the suction port 8, and a water supply line (not shown) is connected to the discharge port 9.

  The inner casing 3 is arranged inside the outer casing 2 and has a configuration in which a plurality of ring members 10 are arranged in the direction of the axis O of the rotating shaft 4. The internal casing 3 is provided with an internal space that communicates with the suction port 8 and the discharge port 9 and repeats the diameter reduction and the diameter expansion. The impeller 6 is accommodated in this internal space. And the casing flow path 7 which distribute | circulates the fluid F which distribute | circulates the impeller 6 from the upstream side to the downstream side is formed in the position between the impellers 6 when the impeller 6 is accommodated. And the discharge port 9 communicate with each other via an impeller 6 and a casing flow path 7.

  The rotating shaft 4 is externally fitted with an impeller 6 and both suction impellers 5 housed in the inner casing 3, and rotates around the axis O together with these. The rotary shaft 4 is rotatably supported with respect to the outer casing 2 and the inner casing 3 by a bearing (not shown), and is rotated by a prime mover (not shown).

  Both suction impellers 5 are housed in the outer casing 2 and are configured to suck the fluid F from the suction port 8.

The plurality of impellers 6 are arranged on the other side (on the right side in the drawing in FIG. 1) on the downstream side in the direction of the axis O with respect to the two suction impellers 5. 4 are accommodated at intervals in the direction of the axis O.
2 and 3, each impeller 6 includes a substantially disk-shaped disk 18 that gradually increases in diameter toward the outflow side, and one end of the outer casing 2 of the rotating shaft 4 from the surface of the disk 18. It has a plurality of blades 19 (blades) that are radially attached to the disk 18 and arranged in the circumferential direction so as to rise to the other side of the axis O serving as a part. Further, the impeller 6 has a cover 20 attached so as to cover the plurality of blades 19 in the circumferential direction from one side in the direction of the axis O. Further, a gap S is defined between the cover 20 and the inner casing 3 so that the impeller 6 and the inner casing 3 do not contact each other. Furthermore, it is defined so that the fluid F circulates in the radial direction surrounded by the surfaces of the disc 18 and the cover 20 provided on both sides of the pair of adjacent blades 19 along the axis O direction of the blades 19. A flow path 23, which is an open space, is defined. Then, the flow path 23 takes in the fluid F with the one side of the blade 19 in the direction of the axis O, that is, the radially inner side as the fluid F inflow side, and the radially outer side as the fluid F outflow side from the tip side of the blade 19. The fluid F is discharged.

  The blades 19 are spaced at regular intervals in the circumferential direction of the axis O, that is, in the rotational direction R so as to rise from a disk curved surface 18a, which will be described later, which is a surface in the axis O direction of the disk 18 around the axis O to the one side in the axis O direction. A plurality are arranged with a gap. Each of the blades 19 is formed to bend toward the rear side in the rotational direction R as it goes from the radially inner side to the outer side of the disk 18. The plurality of blades 19 formed on the impeller 6 are provided on both sides of the blade 19 in the direction of the axis O, and the two surfaces facing the circumferential direction of the axis O of the pair of blades 19 adjacent to each other, A surface facing the front side in the rotation direction R is a pressure surface 19a, and a surface facing the rear side in the rotation direction R is a negative pressure surface 19b. And between the pressure surface 19a and the negative pressure surface 19b of the adjacent blade | wing 19, the flow path 23 through which the fluid F distribute | circulates in the radial direction is defined.

  The end face of the disk 18 facing the one side in the direction of the axis O (left side as viewed in FIG. 2) has a small diameter, and the end face facing the other side has a large diameter. The disk 18 is connected by a disk curved surface 18a whose diameter gradually increases from one side in the axis O direction to the other side in the axis O direction, thereby forming a substantially disk shape as viewed in the axis O direction. As a general umbrella shape.

  In addition, a through-hole 18b that penetrates the disk 18 in the axis O direction is formed inside the disk 18 in the radial direction. The impeller 6 is fixed to the rotating shaft 4 and is rotatable as a unit by inserting the rotating shaft 4 into the through-hole 18b and fitting it.

The disk curved surface 18a, along with the pressure surface 19a and the negative pressure surface 19b of a pair of blades 19 adjacent to each other, are provided on both sides in the direction of the axis O of the blade 19 that defines the flow path 23 through which the fluid F flows in the radial direction. Of the two surfaces, the surface is on the disk 18 side. Further, the disk curved surface 18a is formed with a disk step portion (step portion) 40 protruding from the disk curved surface 18a.
The disk step portion (step portion) 40 is a member that protrudes into a rectangular cross section that is fixed so as to partially change the shape of the disk curved surface 18 a so as to disturb the flow of the fluid F flowing through the flow path 23. The disk stepped portion (stepped portion) 40 is disposed at a position equidistant from the pressure surface 19a and the negative pressure surface 19b facing each other in the circumferential direction in the pair of blades 19 in the circumferential direction. The disk step portion (step portion) 40 extends rearward in the rotational direction R toward the radially outer side in the same manner as the blade 19. In the present embodiment, the flow of the fluid F flowing from the radially inner side to the radially outer side is pushed out by the pressure surface 19a, whereby a flow having a circumferential component is obtained. That is, the disk step portion (step portion) 40 is formed so as to intersect the flow direction of the fluid F so as to block the circumferential component of the flow of the fluid F.

The cover 20 is a member provided integrally with the blades 19 so as to cover the plurality of blades 19 from one side in the axis O direction, and the cover curved surface gradually increases in diameter from one side to the other side in the axis O direction. By being connected by 20a, it has a substantially umbrella shape. That is, in this embodiment, the impeller 6 is a closed impeller having a cover 20.
The cover curved surface 20a is provided on both sides in the axis O direction of the blade 19 that defines the flow path 23 through which the fluid F flows in the radial direction together with the pressure surface 19a and the negative pressure surface 19b of the pair of blades 19 adjacent to each other. One of the two surfaces is the surface on the cover 20 side facing the disk curved surface 18a. The cover curved surface 20a is formed with a cover step portion (step portion) 41 protruding from the cover curved surface 20a.

Similarly to the disk step (step) 40, the cover step (step) 41 is fixed so as to partially change the shape of the cover curved surface 20a so as to disturb the flow of the fluid F flowing through the flow path 23. It is the member which protrudes in the cross-sectional rectangle shape. The cover step portion (step portion) 41 is disposed at a position spaced in the circumferential direction from the pressure surface 19 a and the negative pressure surface 19 b facing each other in the circumferential direction in the pair of blades 19. And the cover step part (step part) 41 is extended toward the back of the rotation direction R as it goes to radial direction outer side similarly to the blade | wing 19. As shown in FIG. That is, in this embodiment, the cover step (step) 41 is formed so as to intersect the flow direction of the fluid F so as to block the flow of the fluid F having a circumferential component pushed out by the pressure surface 19a. Yes.
The disc step portion (step portion) 40 and the cover step portion (step portion) 41 protrude from the disk curved surface 18a and the cover curved surface 20a to such an extent that a part of the disk curved surface 18a and the cover curved surface 20a are slightly raised. It ’s fine. Specifically, even if the cover step portion (step portion) 41 and the disk step portion (step portion) 40 protrude, it is only necessary to form a space in which the fluid F can flow between them.

  Here, the above-described casing flow path 7 is formed so that the fluid F is stepped up so as to connect the respective impellers 6. And the outflow side of both suction impellers 5 is connected to the inflow side of the frontmost impeller 6 provided at one end in the direction of the axis O through a water supply path (not shown), and the outflow side of each impeller 6 Is connected to the inflow side of the adjacent impeller 6 via the casing flow path 7. The outflow side of the last stage impeller 6 provided at the other end in the axis O direction is connected to the discharge port 9.

  The casing flow path 7 includes a suction flow path 22 for introducing the fluid F into the flow path 23 of the impeller 6, a diffuser flow path 24 for introducing the fluid F from the flow path 23, and a fluid F from the diffuser flow path 24. And a return channel 25 into which is introduced.

  The suction flow path 22 is a flow path that changes the direction of the fluid F in the direction of the axis O of the rotary shaft 4 immediately before the impeller 6 after flowing the fluid F from the radially outer side toward the radially inner side. .

  The diffuser flow path 24 communicates with the flow path 23 on the radially inner side, and causes the fluid F pressurized by the impeller 6 to flow outward in the radial direction. The diffuser flow path 24 is provided with a plurality of diffuser vanes 16 arranged at equal intervals in the circumferential direction around the axis O of the rotating shaft 4.

  One end side of the return channel 25 communicates with the diffuser channel 24, and the other end side communicates with the suction channel 22. The return flow path 25 includes a corner portion 26 that reverses the direction of the fluid F that has flowed radially outward through the diffuser flow path 24 so as to face radially inward, and a radially inner side from the radially outer side. It has the straight part 27 extended toward the direction.

  The straight portion 27 is surrounded by the downstream side wall of the partition member integrally attached to the inner casing 3 and the upstream side wall of the extending portion integrally attached to the inner casing 3 and extending radially inward. The flow path. The straight portion 27 is provided with a plurality of return vanes 17 arranged at equal intervals in the circumferential direction around the axis O of the rotating shaft 4.

Next, the operation of the centrifugal pump (rotary machine) 1 having the above configuration will be described.
In the centrifugal pump (rotary machine) 1 of the first embodiment as described above, the fluid F that has flowed into the respective impellers 6 from the radially inward suction flow path 22 near the inlet of the fluid F The pressure is sent out to the diffuser flow path 24 arranged on the radially outer side of the impeller 6 through the flow path 23. The fluid F circulates in the flow path 23, thereby generating a main flow F1 that is pumped out from the radially inner side to the outer side and a secondary flow F2 that inhibits the flow of the main flow F1.

As shown in FIG. 4, the secondary flow F <b> 2 described here causes the fluid F in the flow path 23 to be pushed out from the pressure surface 19 a by rotating the blade 19 around the axis O in the rotation direction R, and the pressure F While flowing toward the negative pressure surface 19b of the adjacent blade 19 along the direction intersecting the surface 19a, it flows in the circumferential direction so as to block the flow of the main flow F1. Specifically, when the fluid F is pushed out from the pressure surface 19a, the secondary flow F2 has an axis line along the disk curved surface 18a of the disk 18 and the cover curved surface 20a of the cover 20 that define the flow path 23 together with the blades 19. It flows in the direction intersecting the pressure surface 19a and outward in the radial direction while spreading in the O direction. The two secondary flows F2 flowing along the disk curved surface 18a and the cover curved surface 20a are respectively a disk step (step) 40 provided on the disk curved surface 18a and a cover step (provided on the cover curved surface 20a). The flow is disturbed by colliding with (stepped portion) 41, and the flow crossing the pressure surface 19a and going outward in the radial direction is weakened.
On the other hand, the flow of the main flow F <b> 1 sent out after being pressurized is not obstructed by flowing through the space between the disk step (step) 40 and the cover step (step) 41 in the flow path 23. It is sent to the flow path 24.

  According to the centrifugal pump (rotary machine) 1 as described above, the disk is disturbed from the disk curved surface 18a and the cover curved surface 20a, which are two surfaces defining the flow path, so as to disturb the flow of the fluid F flowing through the flow path 23. By providing the stepped portion (stepped portion) 40 and the cover stepped portion (stepped portion) 41, the secondary flow F2 flowing along the disk curved surface 18a and the cover curved surface 20a can be disturbed. On the other hand, the disk step portion (step portion) 40 is protruded from the disk curved surface 18a, and the cover step portion (step portion) 41 is protruded from the cover curved surface 20a. It is possible to secure a space for the fluid F to flow between the disk curved surface 18a and the cover curved surface 20a, which are two surfaces, and hardly block the flow of the main flow F1 flowing from the inside in the radial direction toward the outside in the flow path 23. . Therefore, while disturbing the flow and reducing the speed of the secondary flow F2, the secondary flow F2 is weakened, while hardly affecting the disk step (step) 40 and the cover step (step) 41. The mainstream F1 can flow. Thereby, it is possible to efficiently reduce the loss caused by the secondary flow F2 without affecting the main flow F1.

  Further, the disk step portion (step portion) 40 and the cover step portion (step portion) 41 are arranged at positions spaced apart in the circumferential direction from the pressure surface 19a and the negative pressure surface 19b facing the circumferential direction in the pair of blades 19. The secondary flow F2 that is pushed out by the pressure surface 19a and flows in the direction intersecting the pressure surface 19a can be blocked by being formed to extend from the inner side in the direction toward the outer side in the radial direction. That is, the secondary flow F2 flowing along the disk curved surface 18a and the cover curved surface 20a can be made to collide with the protruding disk step (step) 40 and cover step (step) 41, and the flow can be easily performed. Can be disturbed. As a result, it is possible to easily reduce the loss due to the secondary flow F2 without affecting the main flow F1.

Next, a centrifugal pump (rotary machine) 1 according to a second embodiment will be described with reference to FIGS. 5 and 6.
In the second embodiment, the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof is omitted. The centrifugal pump (rotary machine) 1 according to the second embodiment is different from the first embodiment in that the disk curved surface 18a and the cover curved surface 20a each have a depression.

That is, as shown in FIG. 5, in the second embodiment, the disk curved surface 18a has a disk recess (step) 50 that is recessed from the disk curved surface 18a.
The disc concave portion (step portion) 50 is recessed in a rectangular shape by partially changing the shape of the disc curved surface 18 a so as to disturb the flow of the fluid F flowing through the flow path 23. The disk concave portion (step portion) 50 is disposed at a position spaced in the circumferential direction from the pressure surface 19 a and the negative pressure surface 19 b facing the circumferential direction in the pair of blades 19. The disk recess (step) 50 extends rearward in the rotational direction R toward the outer side in the radial direction, like the blade 19. That is, in the present embodiment, the disk recess (step) 50 is formed so as to intersect the flow direction of the fluid F so as to block the flow of the fluid F having a circumferential component pushed out by the pressure surface 19a. .

The cover curved surface 20a has a cover recess (step) 51 that is recessed from the cover curved surface 20a.
Similar to the disk recess (step) 50, the cover recess (step) 51 is recessed in a rectangular cross section by partially changing the shape of the cover curved surface 20 a so as to disturb the flow of the fluid F flowing through the flow path 23. It is. It arrange | positions in the position spaced apart from the pressure surface 19a and the negative pressure surface 19b which oppose the circumferential direction in a pair of blade | wing 19 in the circumferential direction, and is extended toward radial outer side from radial inner side.

In the centrifugal pump (rotary machine) 1 according to the second embodiment as described above, the secondary flow F2 passes through the flow path 23 together with the blades 19 when the fluid F is pushed out from the pressure surface 19a, as in the first embodiment. It flows in the direction intersecting the pressure surface 19a and radially outward while spreading in the direction of the axis O along the disk curved surface 18a of the defining disk 18 and the cover curved surface 20a of the cover 20. As shown in FIG. 6, the two secondary flows F2 flowing along the disk curved surface 18a and the cover curved surface 20a are provided on the disk concave portion (step portion) 50 and the cover curved surface 20a provided on the disk curved surface 18a, respectively. The flow is disturbed by flowing into the cover concave portion (step portion) 51, and the flow toward the outer side in the direction intersecting the pressure surface 19a and in the radial direction is weakened.
On the other hand, the main flow F1 that is sent out after being boosted is sent to the diffuser flow path 24 without being blocked because there is no part that protrudes into the flow path 23 and becomes an obstacle.

  According to the centrifugal pump (rotary machine) 1 of the second embodiment as described above, the disk concave portion (step portion) 50 and the cover concave portion (step portion) 51 are arranged so that the pressure surface 19 a and the pressure surface 19 a facing the circumferential direction in the pair of blades 19 It arrange | positions in the position spaced apart from the negative pressure surface 19b in the circumferential direction, and is extended and depressed toward the radial direction outer side from the radial direction inner side. Therefore, the secondary flow F <b> 2 that is pushed out by the pressure surface 19 a and flows in the direction intersecting the pressure surface 19 a can flow into the disc recess (step) 50 and the cover recess (step) 51. That is, the secondary flow F2 flowing along the disk curved surface 18a and the cover curved surface 20a can be caused to flow into the disk concave portion (step portion) 50 and the cover concave portion (step portion) 51, and the flow of the secondary flow F2 can be easily performed. Can be disturbed. Further, by not providing a stepped portion that protrudes into the flow path 23, the flow of the main flow F1 that flows from the inside in the radial direction toward the outside in the flow path 23 is not blocked. For this reason, the main flow F1 can be made to flow with less influence while weakening the secondary flow F2 by disturbing the flow and reducing the speed of the secondary flow F2. As a result, it is possible to easily reduce the loss due to the secondary flow F2 without affecting the main flow F1.

  In addition, the step part of 1st embodiment and 2nd embodiment is not limited to this embodiment, Both the disk curved surface 18a of the disk 18 and the cover curved surface 20a of the cover 20 protrude or dent. It is not limited to that. For example, the disk curved surface 18a may be provided with a disk step (step) 40, the cover curved surface 20a may be provided with a cover recess (step) 51, and conversely, the disk curved surface 18a may be provided with a disk recess (step). Portion) 50, and a cover step portion (step portion) 41 may be provided on the cover curved surface 20a.

Next, a centrifugal pump (rotary machine) 1 according to a third embodiment will be described with reference to FIGS.
In the third embodiment, the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof is omitted. The centrifugal pump (rotary machine) 1 of the third embodiment is different from the first embodiment in that it has a portion protruding only on the disk curved surface 18a.

That is, as shown in FIG. 7, in the third embodiment, the disk curved surface 18a is formed with a convex portion 60 protruding from the disk curved surface 18a.
The convex portion 60 is formed on a disk curved surface 18 a that is one of the two surfaces that define the flow path 23. The convex portion 60 is a member that protrudes into a rectangular cross section that is fixed so as to partially change the shape of the disk curved surface 18 a so as to disturb the flow of the fluid F flowing through the flow path 23. The convex part 60 is arrange | positioned in the position spaced apart equidistant from the pressure surface 19a and the negative pressure surface 19b which oppose the circumferential direction in a pair of blade | wing 19 in the circumferential direction. Moreover, the convex part 60 is extended toward the back of the rotation direction R as it goes to a radial direction outer side similarly to the blade | wing 19. As shown in FIG. That is, in the present embodiment, the convex portion 60 is formed so as to intersect the flow direction of the fluid F so as to block the flow of the fluid F having a circumferential component pushed out by the pressure surface 19a. And the convex part 60 is a member which protrudes with the protrusion height b of 1/4 with respect to the distance a between the disk curved surface 18a and the cover curved surface 20a.
In addition, the convex part 60 should just be the protrusion height b of 1/4 or less with respect to the distance a between the disk curved surface 18a and the cover curved surface 20a.

In the centrifugal pump (rotary machine) 1 according to the third embodiment as described above, the secondary flow F2 passes through the flow path 23 together with the blades 19 when the fluid F is pushed out from the pressure surface 19a, as in the first embodiment. It flows in the direction intersecting the pressure surface 19a and radially outward while spreading in the direction of the axis O along the disk curved surface 18a of the defining disk 18 and the cover curved surface 20a of the cover 20. Then, as shown in FIG. 8, of the two secondary flows F2 flowing along the disk curved surface 18a and the cover curved surface 20a, the secondary flow F2 flowing along the disk curved surface 18a is provided on the disk curved surface 18a. The flow that is disturbed by colliding with the portion 60 and that goes in the direction intersecting the pressure surface 19a and outward in the radial direction is weakened.
On the other hand, the flow of the main flow F1 that is sent out after being pressurized is sent to the diffuser flow path 24 without being obstructed by flowing through the space between the convex portion 60 in the flow path 23 and the cover curved surface 20a.

  According to the centrifugal pump (rotary machine) 1 of the third embodiment, the convex portion 60 is disposed at a position spaced in the circumferential direction from the pressure surface 19a and the negative pressure surface 19b facing the circumferential direction in the pair of blades 19. In addition, by extending from the radially inner side toward the radially outer side and projecting, the secondary flow F2 that is pushed out by the pressure surface 19a and flows in the direction intersecting the pressure surface 19a can be blocked. And since the protrusion height b of the convex part 60 is 1/4 or less with respect to the distance a between the disk curved surface 18a and the cover curved surface 20a, the flow path 23 is not obstruct | occluded. The flow of the main flow F <b> 1 flowing from the inside in the radial direction toward the outside is not blocked. Therefore, the main flow F1 can be made to flow almost without any influence while easily disturbing the flow by causing the secondary flow F2 flowing along the disk curved surface 18a to collide with the convex portion 60. Thereby, it is possible to efficiently reduce the loss caused by the secondary flow F2 without affecting the main flow F1.

Further, since the convex portion 60 is provided only on the disk curved surface 18a which is one of the two surfaces defining the flow path 23, the convex portion can be easily changed by changing only the disk 18 without changing the cover 20. 60 can be formed. Therefore, the centrifugal pump (rotary machine) 1 that easily disturbs the secondary flow F2 can be obtained by changing the member having one of the two surfaces that define the flow path 23.
The convex portion 60 is not limited to being provided on the disk curved surface 18a as in the present embodiment, but may be provided on the cover curved surface 20a of the cover 20. In other words, the surface of the disk 18 or the cover 20 to be provided with the convex portion 60 may be appropriately selected according to the rotating machine to be used.

Next, a centrifugal pump (rotary machine) 1 according to a fourth embodiment will be described with reference to FIGS. 9 and 10.
In the fourth embodiment, the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof is omitted. The centrifugal pump (rotary machine) 1 of the fourth embodiment is different from the first embodiment in that it has a portion that is recessed only in the disk curved surface 18a.

That is, as shown in FIG. 9, in the fourth embodiment, the disk curved surface 18a is formed with a recess 70 that is recessed from the disk curved surface 18a.
The recess 70 is formed on the disk curved surface 18 a, which is one of the two surfaces defining the flow path 23, so as to disturb the flow of the fluid F flowing through the flow path 23. The concave portion 70 is recessed in a triangular cross section so that the shape of the disk curved surface 18a is partially changed and becomes gradually deeper from the pressure surface 19a toward the negative pressure surface 19b. The concave portion 70 is disposed at a position that is equidistant from the pressure surface 19a and the negative pressure surface 19b facing each other in the circumferential direction in the pair of blades 19. Moreover, the recessed part 70 is extended toward the back of the rotation direction R as it goes to a radial direction outer side similarly to the blade | wing 19. As shown in FIG. That is, in this embodiment, the recess 70 is formed so as to intersect the flow direction of the fluid F so as to block the flow of the fluid F having a circumferential component pushed out by the pressure surface 19a.

In the centrifugal pump (rotary machine) 1 according to the fourth embodiment as described above, the secondary flow F2 passes through the flow path 23 together with the blades 19 when the fluid F is pushed out from the pressure surface 19a, as in the first embodiment. It flows in the direction intersecting the pressure surface 19a and radially outward while spreading in the direction of the axis O along the disk curved surface 18a of the defining disk 18 and the cover curved surface 20a of the cover 20. As shown in FIG. 10, the secondary flow F2 flowing along the disk curved surface 18a out of the two secondary flows F2 flowing along the disk curved surface 18a and the cover curved surface 20a is provided on the disk curved surface 18a. By flowing into the recess 70, the flow is disturbed, and the flow that crosses the pressure surface 19a and goes radially outward is obstructed.
On the other hand, the main flow F1 that is sent out after being boosted is sent to the diffuser flow path 24 without being hindered because there is no portion that protrudes into the flow path 23 and becomes an obstacle.

  According to the centrifugal pump (rotary machine) 1 of the fourth embodiment as described above, the concave portion 70 is disposed at a position spaced in the circumferential direction from the pressure surface 19 a and the negative pressure surface 19 b facing the circumferential direction in the pair of blades 19. The secondary flow F2 that is pushed out by the pressure surface 19a and flows in the direction intersecting the pressure surface 19a can be caused to flow by being recessed from the radially inner side toward the radially outer side. Therefore, the secondary flow F2 flowing along the disk curved surface 18a can be caused to flow into the recess 70, and the flow of the secondary flow F2 can be easily disturbed. In addition, by not providing a stepped portion that protrudes into the flow path 23, the flow of the main flow F1 that flows in the flow path 23 from the radially inner side to the outer side is not hindered. For this reason, the main flow F1 can be made to flow with less influence while weakening the secondary flow F2 by disturbing the flow and reducing the speed of the secondary flow F2. Thereby, it is possible to efficiently reduce the loss caused by the secondary flow F2 without affecting the main flow F1.

  Further, since the recess 70 has a triangular shape so as to gradually become deeper from the pressure surface 19a toward the negative pressure surface 19b, the secondary flow F2 flows into the recess 70 while flowing along the disk curved surface 18a. It becomes easy to collide with the knitting face at the deepest part, and the flow can be disturbed more reliably.

Further, since the concave portion 70 is provided only on the disk curved surface 18a which is one of the two surfaces defining the flow path 23, the convex portion 60 can be easily obtained by remodeling only the disk 18 without changing the cover 20. Can be formed. In particular, the recess 70 only needs to be recessed from the disk curved surface 18a or the cover curved surface 20a, and one surface of the two surfaces that define the flow path 23 for the existing centrifugal pump (rotary machine) 1 as well. The recess 70 can be easily formed after installation by shaving.
The recess 70 is not limited to being provided on the disk curved surface 18a as in the present embodiment, but may be provided on the cover curved surface 20a of the cover 20. In other words, the surface of the disk 18 or the cover 20 to be provided with the recess 70 may be appropriately selected according to the rotating machine used.

The present invention is not limited to the present embodiment, and various modifications are allowed without departing from the scope of the present invention. For example, as a first modification of the present embodiment, a part of the disk curved surface 18a and the cover curved surface 20a are directly deformed.
That is, in the first modification, as shown in FIG. 11, a deformed stepped portion (stepped portion) 80 is provided so as to be integrated with the disk curved surface 18a and the cover curved surface 20a.
The deformed stepped portion (stepped portion) 80 changes a part of the disk curved surface 18a and the cover curved surface 20a, which are the two surfaces defining the flow path 23, so as to disturb the flow of the fluid F flowing through the flow path 23. Is formed. Specifically, the deformed stepped portion (stepped portion) 80 is formed such that a part of the disk curved surface 18a and the cover curved surface 20a is recessed into a triangular cross section so that it gradually becomes deeper from the pressure surface 19a toward the negative pressure surface 19b. After that, it protrudes from the disk curved surface 18a and the cover curved surface 20a.

  In the centrifugal pump (rotary machine) 1 of the first modified example as described above, the secondary flow F2 flows through the flow path 23 together with the blades 19 when the fluid F is pushed out from the pressure surface 19a as in the first embodiment. It flows in the direction intersecting the pressure surface 19a and radially outward while spreading in the direction of the axis O along the disk curved surface 18a of the defining disk 18 and the cover curved surface 20a of the cover 20. Then, as shown in FIG. 12, the two secondary flows F2 flowing along the disk curved surface 18a and the cover curved surface 20a are applied to deformation step portions (step portions) 80 provided on the disk curved surface 18a and the cover curved surface 20a, respectively. After the flow is disturbed by flowing in, the deformed stepped portion (stepped portion) 80 protrudes and collides to be further disturbed. Thereby, the flow which goes to the direction which cross | intersects the pressure surface 19a and radial direction outer side is weakened.

  According to the centrifugal pump (rotary machine) 1 of the first modified example, the secondary flow F2 is caused to protrude while being gradually depressed by the deformed step portion (step portion) 80, so that the secondary flow F2 is generated by the disc curved surface 18a and the cover curved surface. While flowing along 20a, it flows into the recessed portion of the deformed step portion (step portion) 80 and collides with the wall surface protruding at the deepest portion, so that the flow can be disturbed more violently. Therefore, the secondary flow F2 can be weakened by further reducing the speed of the secondary flow F2.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

In addition, although this embodiment demonstrated the blade | wing 19 used for the impeller 6 as the centrifugal pump (rotary machine) 1 which is a turbo machine, it is not limited to this, For example, the blade | wing of a water turbine 19 or an impeller of a gas turbine. Further, even the centrifugal pump (rotary machine) 1 is not limited to the blade 19 of the impeller 6. For example, by providing the diffuser vane 16 with a stepped portion, a convex portion 60, or a concave portion 70, the diffuser flow The secondary flow F2 in the path 24 is reduced, and the step, the convex portion 60, and the concave portion 70 are provided in the return vane 17, thereby reducing the secondary flow F2 in the return passage 25.
Moreover, the shape of the step part in each embodiment is not limited to the shape of this embodiment, For example, you may protrude in the cross-sectional triangle shape or cross-sectional circle shape, and you may be depressed.
Furthermore, the stepped portion is not limited to extending in the radial direction with the same cross-sectional shape. For example, the stepped portion is formed from the middle of the radial direction, and the amount of protrusion or depression is gradually increased. It may be formed so as to be large and disturb the secondary flow of the fluid F that flows most on the outflow side. By being formed in this way, the influence on the mainstream F1 can be further suppressed.

Further, the stepped portion in each embodiment is not limited to continuously extending from the inflow side of the fluid F that is radially inward toward the outflow side of the fluid F that is radially outward. For example, the stepped portion may be formed in a discontinuous shape and partially formed in the radial direction, or may be formed only in the radial direction outside or only in the radial direction inside.
Furthermore, the step portion in each embodiment is not limited to being disposed at a position that is equidistant from the pressure surface 19a and the negative pressure surface 19b in the circumferential direction. For example, it may be arranged at a position close to either the pressure surface 19a or the negative pressure surface 19b. That is, the stepped portion only needs to be disposed at a position that more effectively blocks the secondary flow, which is the flow of the fluid F having a circumferential component.
Moreover, the step part in each embodiment may be arrange | positioned in multiple places between the pressure surface 19a and the negative pressure surface 19b. By disposing the step portions at a plurality of locations, the flow of the fluid F can be more efficiently disturbed.
Further, the stepped portion in each embodiment is not limited to extending backward in the rotational direction R as it goes outward in the radial direction, like the blade 19. In other words, the blade 19 may be disposed at an arbitrary angle with respect to the pressure surface 19a and the negative pressure surface 19b.

O ... axis F ... fluid R ... rotation direction F1 ... main flow F2 ... secondary flow 1 ... centrifugal pump (rotary machine) 2 ... outer casing 3 ... inner casing 4 ... rotation shaft 5 ... double suction impeller 6 ... impeller 18 ... disc 18a ... disk curved surface 18b ... through hole 19 ... blade 19a ... pressure surface 19b ... negative pressure surface 20 ... cover 20a ... cover curved surface 23 ... flow path S ... gap 7 ... casing flow path 8 ... suction port 9 ... discharge port 10 ... ring member DESCRIPTION OF SYMBOLS 11, 12 ... Casing cover 13, 14 ... Fastening bolt 16 ... Diffuser vane 17 ... Return vane 22 ... Suction flow path 24 ... Diffuser flow path 25 ... Return flow path 26 ... Corner part 27 ... Straight part 40 ... Disc step part (stage) 41) Cover step (step) 50 ... Disc recess (step) 51 ... Cover recess (step) ) 60 ... protrusion 70 ... recess 80 ... deformable stepped portion (stepped portion)

Claims (5)

A plurality of blades extending in the radial direction about the axis, and a plurality of blades arranged at intervals in the circumferential direction;
Two surfaces that are provided on both sides in the axial direction of the blades and define a flow path through which a fluid flows in a radial direction together with a pair of the blades adjacent to each other;
A rotating machine characterized in that a step portion for disturbing a flow of fluid flowing through the flow path is formed on each of the two surfaces.   At least one of the stepped portions protrudes from the surface and extends from the radially inner side toward the radially outer side at a position spaced in the circumferential direction from the circumferentially opposed surfaces of the pair of blades. The rotating machine according to claim 1, characterized in that:   At least one of the stepped portions is recessed from the surface and extends from the radially inner side to the radially outer side at a position spaced in the circumferential direction from the circumferentially opposed surfaces of the pair of blades. The rotating machine according to claim 1, characterized in that: A plurality of blades extending in the radial direction about the axis, and a plurality of blades arranged at intervals in the circumferential direction;
Two surfaces that are provided on both sides in the axial direction of the blades and define a flow path through which a fluid flows in a radial direction together with a pair of the blades adjacent to each other;
One of the two surfaces protrudes from the surface so as to disturb the flow of the fluid flowing through the flow path, and has a diameter separated from a surface facing the circumferential direction in the pair of blades. A convex portion extending from the inner side in the direction toward the outer side in the radial direction is formed,
A rotating machine characterized in that a protruding height of the convex portion from the surface is ¼ or less of a distance between the two surfaces. A plurality of blades extending in the radial direction around the axis and arranged in a circumferential direction at intervals,
Two surfaces that are provided on both sides in the axial direction of the blades and define a flow path through which a fluid flows in a radial direction together with a pair of the blades adjacent to each other;
One of the two surfaces is recessed from the surface so as to disturb the flow of the fluid flowing through the flow path, and has a diameter spaced from the surface facing the circumferential direction in the pair of blades. A rotating machine characterized in that a recess extending from the inner side in the direction toward the outer side in the radial direction is formed.

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