JP2017145781A - Bell-mouth, pump, manufacturing method of bell-mouth, and manufacturing method of pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bell-mouth capable of being easily manufactured and smoothly circulating a fluid, a pump including the bell-mouth, a manufacturing method of the bell-mouth, and a manufacturing method of the pump including the bell-mouth.SOLUTION: A bell-mouth includes a peripheral wall, the peripheral wall has an annular first opening end, an annular second opening end separating from the first opening end in an axial direction along an axis, and having a diameter smaller than the first opening end, and a flow channel extended between the first opening end and the second opening end. The peripheral wall includes a curved portion having a curved cross-sectional shape on a cross-section including the axis in at least a part of a region in the axial direction, and the curved portion is composed of at least a part of a plurality of metallic plates arranged in the circumferential direction around the axis.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a bell mouth, a pump, a manufacturing method of a bell mouth, and a manufacturing method of a pump.

The bell mouth is applied to various fluid devices such as a pump and constitutes a suction port of the fluid device. As the bell mouth, one made of sheet metal is known.
For example, a suction casing applied to the pump disclosed in Patent Document 1 is formed by joining a plurality of hollow frustoconical ring members in a bell mouth shape.
The suction bell applied to the pump disclosed in Patent Document 2 is formed by spinning a metal plate material.

JP 2007-247414 A JP2013-108388A

As disclosed in Patent Document 1, in a suction casing in which a plurality of ring-shaped frustoconical ring members are joined in a bell mouth shape, the taper angles of the ring members joined to each other are different. For this reason, an edge is formed on the inner surface of the suction casing in the joining region of the ring member, and the inner surface cannot be sufficiently smoothed. As a result, separation of the fluid flow occurs in the joining region of the ring member, and the fluid flow in the suction casing may become uneven.
On the other hand, as disclosed in Patent Document 2, when a suction bell is formed by spinning press processing a metal plate material, the inner surface of the suction bell can be made smooth. However, since the spinning press process requires advanced technology compared to the press process, the manufacturing cost of the suction bell is increased.

  In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a bell mouth that is easy to manufacture and allows fluid to flow smoothly, a pump including the bell mouth, a method for manufacturing the bell mouth, and the bell It is providing the manufacturing method of a pump provided with a mouse.

(1) A bell mouth according to at least one embodiment of the present invention includes:
An annular first opening end, an annular second opening end that is spaced apart from the first opening end in the axial direction along the axis and has a smaller diameter than the first opening end, and the first opening end; Comprising a peripheral wall having a flow path extending between the second open ends;
The peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a part of the region in the axial direction;
The curved portion is configured by at least a part of a plurality of metal plates arranged in a circumferential direction around the axis.

According to the configuration (1), the peripheral wall includes a curved portion in at least a partial region in the axial direction, and has a cross-sectional shape in which the curved portion is curved in a cross section including the axial line. Therefore, the inner surface of the bending portion is smooth, and the fluid flowing through the flow path in the bell mouth is prevented from peeling off from the inner surface of the bending portion. For this reason, it is prevented that the flow of the fluid in the flow path in the bell mouth becomes uneven, and the fluid can flow smoothly.
On the other hand, since the bending portion is constituted by a plurality of metal plates arranged in the circumferential direction, it is not necessary to form the bending portion by spinning. For this reason, the bell mouth of the said structure (1) can be manufactured easily.

(2) In some embodiments, in the configuration (1),
The joints between the plurality of metal plates extend in a radial direction perpendicular to the axis.

The seam between the metal plates can be smoothed by polishing or the like, but the seam may be uneven. In such a case, depending on the flow direction of the fluid with respect to the extending direction of the seam, the flow may be separated due to the unevenness.
Here, in general, the flow direction of the fluid in the bellmouth mouth is substantially along the axial direction. Therefore, the flow of the fluid flows along a plane including the axis and an arbitrary radial direction. In this regard, according to the configuration (2), when viewed in the axial direction, the seam between the metal plates extends in the radial direction perpendicular to the axial line, and the fluid follows a plane including the axial line and the seam. Can flow like. For this reason, the extending direction of the seam between the metal plates can be made substantially coincident with the fluid flow direction. As a result, even if the seam is uneven, the fluid flow is prevented from peeling off.

(3) In some embodiments, in the configuration (1),
The joints between the plurality of metal plates extend spirally around the axis.
The seam between the metal plates can be smoothed by polishing or the like, but the seam may be uneven. In such a case, depending on the flow direction of the fluid with respect to the extending direction of the seam, the flow may be separated due to the unevenness.
Here, generally, the flow direction of the fluid in the bell mouth is substantially along the axial direction, but in some cases, the flow of the fluid may include a swirling component. In such a case, according to the above configuration (3), since the seam between the metal plates extends spirally around the axis, even if the fluid flow includes a swirling component, the metal plate The extending direction of the seam between the plates can be made substantially coincident with the flow direction of the fluid. For this reason, even if the seam is uneven, the fluid flow is prevented from peeling off.

(4) In some embodiments, in any one of the configurations (1) to (3),
The peripheral wall further includes at least one taper portion made of metal in a region different from the curved portion in the axial direction,
The at least one taper portion has a straight cross-sectional shape inclined with respect to the axis in a cross section including the axis.

Even if the peripheral wall includes a tapered portion as in the configuration (4), depending on the position of the tapered portion in the axial direction, the influence of the tapered portion on the fluid flow is small, and the fluid smoothly flows in the bell mouth. Can flow.
On the other hand, since the peripheral wall includes the tapered portion, the shape of the bell mouth can be simplified, and the bell mouth can be easily manufactured.

(5) In some embodiments, in the configuration (4),
The curved portion and the at least one tapered portion are constituted by the plurality of metal plates.
According to the configuration (5), a part of the metal plate constitutes a tapered portion, and the bell mouth can be easily manufactured only by connecting a plurality of metal plates.

(6) The pump according to at least one embodiment of the present invention is:
A main casing;
An impeller disposed in the main casing;
A bell mouth constituting a suction casing connected to the main casing, and
The bell mouth is
A ring-shaped first opening end, a second opening end located on the main casing side in the axial direction along the axis line than the first opening end, and having a smaller diameter than the first opening end; A peripheral wall having a flow path extending between one open end and the second open end;
The peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a part of the region in the axial direction;
The curved portion is configured by at least a part of a plurality of metal plates arranged in a circumferential direction around the axis.

  According to the configuration (6), since the fluid smoothly flows in the bell mouth configuring the suction casing, the pump can operate efficiently.

(7) A method for manufacturing a bell mouth according to at least one embodiment of the present invention includes:
A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
In the method for manufacturing a bell mouth, the peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a partial region in the axial direction.
A circumferentially divided plate preparing step of preparing a plurality of metal plates arranged in the circumferential direction around the axis;
A circumferentially divided plate joining step for forming the curved portion by joining the plurality of metal plates to each other.

  According to the said structure (7), a bell mouth can be easily manufactured by mutually joining the some metal board arranged in the circumferential direction around an axis line.

(8) A method for manufacturing a pump according to at least one embodiment of the present invention includes:
A main casing;
An impeller disposed in the main casing;
A bell mouth constituting a suction casing connected to the main casing, and
The bell mouth is
A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
In the method for manufacturing a pump, the peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a partial region in the axial direction.
A circumferentially divided plate preparing step of preparing a plurality of metal plates arranged in the circumferential direction around the axis;
A circumferentially divided plate joining step for forming the curved portion by joining the plurality of metal plates to each other.

  According to the configuration (8), a bell mouth can be easily manufactured by joining together a plurality of metal plates arranged in the circumferential direction around the axis, and as a result, a pump can be easily manufactured. Is possible.

(9) A method for manufacturing a bell mouth according to at least one embodiment of the present invention includes:
A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
The peripheral wall is
The peripheral wall is located in at least a part of the region in the axial direction, and has a curved portion having a curved cross-sectional shape in a cross section including the axial line;
At least one tapered portion that is located in a region different from the curved portion in the axial direction and has a straight cross-sectional shape that is inclined with respect to the axial line in a cross section including the axial line;
A manufacturing method of bell mouth, comprising:
A spinning process for forming the curved portion by forming a metal cylinder by spinning.

According to the said structure (9), the inner surface of a curved part can be made smooth by shape | molding the curved part contained in a surrounding wall by spinning process, and peeling of the flow of a fluid can be prevented. On the other hand, even if the peripheral wall includes the tapered portion, depending on the position of the tapered portion in the axial direction, the influence of the tapered portion on the fluid flow is small, and the fluid can smoothly flow in the bell mouth.
In addition, since it is not necessary to form the entire peripheral wall by spinning, the bell mouth can be easily manufactured.

(10) A method for manufacturing a pump according to at least one embodiment of the present invention includes:
A main casing;
An impeller disposed in the main casing;
A bell mouth constituting a suction casing connected to the main casing, and
The bell mouth is
A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
The peripheral wall is
A curved portion located in at least a part of the axial direction and having a curved cross-sectional shape in a cross section including the axial line;
At least one tapered portion that is located in a region different from the curved portion in the axial direction and has a straight cross-sectional shape that is inclined with respect to the axial line in a cross section including the axial line;
A method for manufacturing a pump, comprising:
A spinning process for forming the curved portion by forming a metal cylinder by spinning.

According to the said structure (10), the inner surface of a curved part can be made smooth by shape | molding the curved part contained in a surrounding wall by spinning process, and peeling of the flow of a fluid can be prevented. On the other hand, even if the peripheral wall includes the tapered portion, depending on the position of the tapered portion in the axial direction, the influence of the tapered portion on the fluid flow is small, and the fluid can smoothly flow in the bell mouth. Thus, since the fluid flows smoothly in the bell mouth constituting the suction casing, the pump can operate efficiently.
Moreover, since it is not necessary to shape | mold the whole surrounding wall by a spinning process, a bellmouth can be manufactured easily and, as a result, a pump can be manufactured easily.

  According to at least one embodiment of the present invention, a bell mouth that is easy to manufacture and fluid can flow smoothly, a pump including the bell mouth, a method for manufacturing the bell mouth, and a pump including the bell mouth are manufactured. A method is provided.

It is sectional drawing which shows the schematic structure of the fluid machine to which the bellmouth which concerns on one Embodiment of this invention was applied. It is a figure which shows schematically the bell mouth in FIG. 1, (a) is a top view, (b) is a longitudinal cross-sectional view. FIG. 3 is a side view schematically showing one plate included in the bell mouth of FIG. 2. It is a figure which shows schematically the bell mouth which concerns on other one Embodiment, (a) is a top view, (b) is a longitudinal cross-sectional view. FIG. 5 is a side view schematically showing one plate included in the bell mouth of FIG. 4. It is a figure which shows schematically the bell mouth which concerns on other one Embodiment, (a) is a top view, (b) is a longitudinal cross-sectional view. It is a perspective view which shows schematically the taper part contained in the bell mouth of FIG. It is a longitudinal cross-sectional view which shows schematically the bell mouth which concerns on other one Embodiment. It is a longitudinal cross-sectional view which shows schematically the bell mouth which concerns on other one Embodiment. It is a longitudinal cross-sectional view which shows schematically the bell mouth which concerns on other one Embodiment. It is a longitudinal cross-sectional view which shows schematically the bell mouth which concerns on other one Embodiment. It is a flowchart which shows the schematic procedure of the manufacturing method of the bellmouth which concerns on one Embodiment of this invention. It is a flowchart which shows the schematic procedure of the manufacturing method of the bellmouth which concerns on other one Embodiment. It is a flowchart which shows the schematic procedure of the manufacturing method of the bellmouth which concerns on other one Embodiment. It is a schematic diagram for demonstrating the spinning process used for the manufacturing method of the bell mouth shown in FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also concave projections and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a fluid machine 3 to which a bell mouth 1A according to an embodiment of the present invention is applied. 2A and 2B are diagrams schematically showing the bell mouth 1A in FIG. 1, in which FIG. 2A is a plan view and FIG. 2B is a longitudinal sectional view. FIG. 3 is a side view schematically showing one plate included in the bell mouth 1A of FIG. 4A and 4B are diagrams schematically showing a bell mouth 1B according to another embodiment, wherein FIG. 4A is a plan view and FIG. 4B is a longitudinal sectional view. FIG. 5 is a side view schematically showing one plate included in the bell mouth 1B of FIG. 6A and 6B are diagrams schematically showing a bell mouth 1C according to another embodiment, wherein FIG. 6A is a plan view and FIG. 6B is a longitudinal sectional view. FIG. 7 is a perspective view schematically showing a tapered portion included in the bell mouth 1 </ b> C of FIG. 6. FIG. 8 is a longitudinal sectional view schematically showing a bell mouth 1D according to another embodiment. FIG. 9 is a longitudinal sectional view schematically showing a bell mouth 1E according to another embodiment. FIG. 10 is a longitudinal sectional view schematically showing a bell mouth 1F according to another embodiment. FIG. 11 is a longitudinal sectional view schematically showing a bell mouth 1G according to another embodiment.

FIG. 1 shows a pump 3a as an example of a fluid machine 3 to which bellmouths 1A to 1G can be applied. The pump 3a is, for example, a circulating water pump used in a power plant, and is a mixed flow pump, and has a function of sucking and feeding seawater in order to supply seawater to a condenser (not shown).
The pump 3a includes an outer casing (main casing) 5, an inner casing 7, an impeller 9, a rotating shaft 11, and a bell mouth 1A.
The outer casing 5 has a hollow cylindrical shape and is disposed along the axis 13. When the pump 3a is a circulating water pump, the axis 13 extends along the vertical direction.

  The inner casing 7 has a hollow cylindrical shape and is arranged coaxially inside the outer casing 5. The inner casing 7 is supported by the outer casing 5 via a support member 15 provided between the outer casing 5 and the inner casing 7.

  The impeller 9 is rotatably arranged at one end side of the outer casing 5, in other words, inside the upstream side in the fluid flow direction. The impeller 9 includes, for example, a conical hub 17 disposed coaxially with the outer casing 5 and the inner casing 7, and a plurality of blades 19 attached to the hub 17. The hub 17 is disposed so as to close one end side of the inner casing 7, in other words, the upstream side in the fluid flow direction, and a fluid flow path 21 between the hub 17 and the inner casing 7 and the outer casing 5. Is formed. The flow path 21 has a cylindrical shape, and a plurality of blades 19 arranged in the circumferential direction around the axis 13 are disposed in the flow path 21.

  The rotating shaft 11 extends along the axis 13, and one end side of the rotating shaft 11 is fixed coaxially to the hub 17. The rotating shaft 11 extends inside the inner casing 7 and penetrates the other end side of the inner casing 7. A bending tube 23 is connected to the other end side of the outer casing 5, and the rotary shaft 11 extends through the wall of the bending tube 23 in a liquid-tight manner to the outside of the bending tube 23. The other end of the rotary shaft 11 located outside the bending tube 23 is connected to the drive shaft 27 via a joint 25.

The bell mouth 1 </ b> A is coaxially attached to one end side of the outer casing 5. That is, the bell mouth 1 </ b> A is attached to the fluid suction side of the outer casing 5, and constitutes a suction casing connected to the outer casing 5.
In the pump 3a, the drive shaft 27 is connected to a drive motor (not shown), and the rotation shaft 11 and the impeller 9 rotate as the drive shaft 27 rotates. By the rotation of the impeller 9, a fluid flow is generated in the outer casing 5 by the plurality of blades 19, the surrounding fluid flows into the bell mouth 1 </ b> A, and is sent to the bending tube 23 through the flow path 21. . For example, when the pump 3a is a circulating water pump used at a power plant, seawater sucked up by the pump 3a is sent to a condenser.

Hereinafter, the bell mouths 1A to 1G will be described.
As shown in FIGS. 2, 4, 6, 8, 9, 10, and 11, the bell mouths 1 </ b> A to 1 </ b> G have a peripheral wall 30. The peripheral wall 30 has a first opening end 32, a second opening end 34, and a flow path 36.
The first open end 32 is located on one end side in the axial direction of the peripheral wall 30 (hereinafter also simply referred to as the axial direction) and has a ring shape. In the present embodiment, since the axis of the peripheral wall 30 coincides with the axis 13, the axis of the peripheral wall 30 is also referred to as the axis 13.

  The second open end 34 has an annular shape and a smaller diameter than the first open end 32. The second opening end 34 is separated from the first opening end 32 in the axial direction. The second opening end 34 is coaxially connected to one end side of the outer casing 5. Therefore, in the fluid flow direction, the first opening end 32 is located on the upstream side, and the second opening end 34 is located on the downstream side.

  The flow path 36 is partitioned inside the peripheral wall 30 and extends between the first opening end 32 and the second opening end 34. Accordingly, the first open end 32 is located at the inlet of the flow path 36, and the second open end 34 is located at the outlet of the flow path 36. The cross-sectional area of the flow path 36, in other words, the flow path area, gradually decreases as it approaches from the first opening end 32 toward the second opening end 34. The flow path 36 communicates with the flow path 21 in the outer casing 5.

The peripheral wall 30 includes a curved portion 38 in at least a partial region in the axial direction, and the curved portion 38 has a curved cross-sectional shape in a cross section including the axial line 13. Accordingly, in the curved portion 38, the diameter of the flow path 36 changes nonlinearly corresponding to the position in the axial direction.
As shown in FIGS. 2, 4, 6, 8, 9, and 10, in the bell mouths 1 </ b> A to 1 </ b> F except for the bell mouth 1 </ b> G described later, the bending portion 38 is around the axis 13. It is comprised by the at least one part of the some metal board (circumferential direction division | segmentation board) 40 (40a, 40b, 40c) arranged in the circumferential direction. The plurality of metal plates 40 are joined to each other.

  3 and 5 schematically show one plate 40 (40a, 40b) constituting the bending portion 38 of FIGS. 2 and 4. As shown in FIGS. 2 to 6 and FIGS. 8 to 10, the plate 40 (40 a, 40 b, 40 c) extends in the axial direction and extends in the radial direction perpendicular to the axis 13. As shown in FIGS. 2, 4, and 10, when the peripheral wall 30 is configured only by a plurality of plates 40 (40 a, 40 b, 40 c), one end 41 a of each plate 40 (40 a, 40 b, 40 c) A part of the first opening end 32 is constituted, and the other end 41b of each plate 40 (40a, 40b, 40c) constitutes a part of the second opening end 34.

Each plate 40 (40a, 40b, 40c) has a predetermined width in the circumferential direction around the axis 13. The width of each plate 40 (40a, 40b, 40c) (the central angle around the axis 13) differs according to the number of arrangement of the plurality of plates (40a, 40b, 40c). It is set so as to surround the axis 13 when 40b) is joined.
The plate 40 (40a, 40b, 40c) has a side edge 41c extending between the one end 41a and the other end 41b, and the side edges 41c of the plurality of plates 40 (40a, 40b, 40c) are joined to each other. The

According to the bell mouths 1A to 1F having the above-described configuration, the peripheral wall 30 includes the curved portion 38 in at least a part of the region in the axial direction, and has a cross-sectional shape in which the curved portion 38 is curved in the cross section including the axis 13. Have. Therefore, the inner surface of the curved portion 38 is smooth, and the fluid flowing through the flow path 36 in the bell mouths 1 </ b> A to 1 </ b> E is prevented from peeling from the inner surface of the curved portion 38. For this reason, it is prevented that the flow of the fluid in the flow path 36 in Bellmouth 1A-1F becomes non-uniform | heterogenous, and a fluid can flow smoothly.
On the other hand, according to the bell mouths 1A to 1F having the above-described configuration, the bending portion 38 is configured by the plurality of metal plates 40 arranged in the circumferential direction, and thus the bending portion 38 needs to be formed by spinning. There is no. For this reason, the bell mouth 1A-1F of the said structure can be manufactured easily.

  And since the fluid flows smoothly in the bellmouth 1A-1F which comprises a suction casing, the pump 3a which has the bellmouth 1A-1F can operate | move efficiently.

In some embodiments, like the bell mouths 1A, 1C to 1F shown in FIGS. 2, 6, 8, 9 and 10, the joints between the plurality of metal plates 40 (40a, 40c) are provided. (Joint portion) 42 (42a, 42c) extends in the radial direction orthogonal to the axis 13 when viewed in the axial direction. The plates 40 (40a, 40c) can be joined to each other, for example, by welding.
The joints 42 (42a, 42c) between the metal plates 40 (40a, 40c) can be smoothed by polishing or the like, but the joints 42 may be uneven. In such a case, depending on the flow direction of the fluid with respect to the extending direction of the seam 42, the flow may be separated due to the unevenness.

  Here, in general, the flow direction of the fluid in the bellmouth mouth is substantially along the axial direction. Accordingly, the fluid flows along a plane including the axis 13 and an arbitrary radial direction. In this regard, according to the bell mouths 1A, 1C to 1F having the above-described configuration, the seams 42 (42a, 42c) between the metal plates 40 (40a, 40c) are orthogonal to the axis 13 when viewed in the axial direction. Since it extends in the radial direction, the fluid can flow along a plane including the axis 13 and the seams 42 (42a, 42c). For this reason, the extending direction of the joints 42 (42a, 42c) between the metal plates 40 and the fluid flow direction can be substantially matched. As a result, even if the seam 42 (42a, 42c) has irregularities, the fluid flow is prevented from peeling off.

In some embodiments, like the bell mouth 1B shown in FIG. 4, the joints 42 (42 b) between the plurality of metal plates 40 extend spirally around the axis 13.
The joint 42 (42b) between the metal plates 40 can be smoothed by polishing or the like, but the joint 42 may be uneven. In such a case, depending on the flow direction of the fluid with respect to the extending direction of the seam 42, the flow may be separated due to the unevenness.

  Here, generally, the flow direction of the fluid in the bell mouth is substantially along the axial direction, but in some cases, the flow of the fluid may include a swirling component. In such a case, according to the bell mouth 1B having the above-described configuration, since the seam 42 between the metal plates 40 extends spirally around the axis 13, the fluid flow includes a swirling component. Even so, the extending direction of the seam 42 (42b) between the metal plates 40 and the fluid flow direction can be substantially matched. For this reason, even if the seam 42 (42b) has irregularities, the fluid flow is prevented from peeling off.

  When the seam 42 (42b) extends spirally, the extending direction of the seam 42 (42b) is appropriately set in consideration of the swirl component of the fluid obtained by CFD analysis (computational fluid dynamics analysis) or the like. Is possible. The swirl component of the fluid also changes depending on the installation environment of the fluid machine 3, and when the pump 3a is a circulating water pump, it also changes depending on the shape of the water intake tank in which the pump 3a is installed.

  In some embodiments, like the bell mouths 1C to 1G shown in FIGS. 6, 8, 9, 10 and 11, the peripheral wall 30 is made of metal in a region different from the curved portion 38 in the axial direction. It further includes at least one taper portion 44 made of metal. The taper portion 44 has a straight cross-sectional shape that is inclined with respect to the axis line 13 in a cross section including the axis line 13. For example, the taper portion 44 has a hollow truncated cone shape. Therefore, in the taper portion 44, the diameter of the flow path 36 changes linearly corresponding to the position in the axial direction.

In the bell mouths 1 </ b> C to 1 </ b> G having the above-described configuration, the taper portion 44 has a straight cross-sectional shape in the cross section including the axis 13, and thus there is a possibility that the fluid flow may be separated at the taper portion 44. In addition, the fluid flow may be separated at the joint portion 46 between the taper portion 44 and the curved portion 38. However, even if the peripheral wall 30 includes the tapered portion 44, depending on the position of the tapered portion 44 in the axial direction, the influence of the tapered portion 44 on the fluid flow is small, and the fluid smoothly flows in the bell mouths 1C to 1F. Can flow.
On the other hand, because the peripheral wall 30 includes the tapered portion 44, the shape of the bell mouths 1C to 1G can be simplified, and the bell mouths 1C to 1G can be easily manufactured.

  In some embodiments, like the bell mouth 1C shown in FIG. 6, the curved portion 38 is located on the first opening end 32 side, and the tapered portion 44 is located on the second opening end 34 side. The flow direction of the fluid may be greatly bent near the first opening end 32. In this regard, if the bending portion 38 is positioned on the first opening end 32 side as in the bell mouth 1C having the above-described configuration, even if the fluid flow is greatly bent near the first opening end 32, the bending portion 38 can prevent flow separation.

  In some embodiments, like the bell mouths 1D to 1G shown in FIGS. 8 to 11, the tapered portion 44 is located on the first opening end 32 side, and the curved portion 38 is located on the second opening end 34 side. doing. The flow rate of the fluid increases as it goes from the first opening end 32 toward the second opening end 34, and is easy to peel off on the second opening end 34 side. In addition, since the second opening end 34 is closer to the blade 19 than the first opening end 32, it is important to adjust the flow on the second opening end 34 side. In this regard, if the bending portion 38 is located on the second opening end 34 side as in the bell mouths 1D to 1G having the above-described configuration, the bending portion 38 causes the flow separation on the second opening end 34 side. The flow can be adjusted while preventing.

FIG. 7 is a perspective view schematically showing the shape of the tapered portion 44 applied to the bell mouth 1C of FIG. In some embodiments, like the bell mouths 1C-1E, 1G shown in FIGS. 6, 8, 9 and 11, the tapered portion 44 is manufactured separately from the curved portion 38, and The curved portions 38 are joined to each other. In this case, the taper portion 44 can be manufactured by, for example, bending a metal plate and joining both ends by welding. The curved portion 38 and the tapered portion 44 can be joined by welding or flange connection, for example.
In addition, the code | symbol 45 in FIG. 7 has shown the junction part of the board | plate material.

  In some embodiments, like the bell mouth 1E shown in FIG. 9, the peripheral wall 30 has two or more tapered portions 44 (44a, 44b) having different inclinations with respect to the axis 13 in a cross section including the axis 13. Contains. According to the bell mouth 1E having the above-described configuration, the peripheral wall 30 includes two or more tapered portions 44 (44a, 44b) having different inclinations, so that flow separation can be suppressed. In addition, the some taper part 44 (44a, 44b) can be joined by welding or a flange connection, for example.

  In some embodiments, although not shown, the curved portion 38 may be located between the plurality of tapered portions 44 in the axial direction.

In some embodiments, like the bell mouth 1F shown in FIG. 10, the curved portion 38 and the at least one tapered portion 44 are configured by a plurality of metal plates 40 arranged in the circumferential direction. That is, the plurality of metal plates 40 may constitute only the curved portion 38 as in the bell mouths 1A to 1E shown in FIGS. 2, 4, 6, 8, and 9. Like the bell mouth 1 </ b> F shown in FIG. 10, a taper portion 44 integrated with the bending portion 38 may be formed together with the bending portion 38.
According to the bell mouth 1F having the above configuration, a part of the metal plate 40 constitutes the curved portion 38, and another part of the metal plate 40 constitutes the tapered portion 44. The bell mouth 1F can be easily manufactured simply by connecting the made plates 40.

Hereinafter, a bell mouth 1G according to an embodiment of the present invention will be described. As described above, the bell mouth 1G includes the peripheral wall 30 similarly to the bell mouths 1C to 1F, and the peripheral wall 30 includes the curved portion 38 and at least one tapered portion 44.
The bell mouth 1G is different from the bell mouth 1C to 1F in that the curved portion 38 is formed by molding a metal cylinder by spinning.

According to the bell mouth 1G having the above-described configuration, the curved portion 38 included in the peripheral wall 30 is molded by spinning, whereby the inner surface of the curved portion 38 can be smoothed and fluid flow separation can be prevented. Can do. On the other hand, even if the peripheral wall 30 includes the tapered portion 44, depending on the position of the tapered portion 44 in the axial direction, the influence of the tapered portion 44 on the fluid flow is small, and the fluid flows smoothly in the bell mouth 1G. Can do.
Further, since it is not necessary to form the entire peripheral wall 30 by spinning, the bell mouth 1G can be easily manufactured.

  And since the fluid flows smoothly in the bell mouth 1G which comprises a suction casing, the pump 3a which has the bell mouth 1G can operate | move efficiently.

  Hereinafter, the manufacturing method of the bell mouth which concerns on embodiment of this invention is demonstrated. FIG. 12 is a flowchart showing a schematic procedure of a method for manufacturing a bell mouth according to an embodiment of the present invention. FIG. 13 is a flowchart illustrating a schematic procedure of a method for manufacturing a bell mouth according to another embodiment. FIG. 14 is a flowchart showing a schematic procedure of a method for manufacturing a bell mouth according to another embodiment. FIG. 15 is a schematic view for explaining the spinning process used in the method for manufacturing the bell mouth of FIG.

The bell mouth manufacturing method shown in FIG. 12 is applicable to the manufacturing of bell mouths 1A, 1B, and 1F, and includes a circumferential divided plate preparation step S1 and a circumferential divided plate joining step S2.
In the circumferential direction divided plate preparation step S1, a plurality of metal plates (circumferential direction divided plates) 40 arranged in the circumferential direction around the axis 13 are prepared. For example, the plate 40 can be prepared and prepared by subjecting a metal plate material to press forming.
In the circumferential divided plate joining step S <b> 2, the plurality of metal plates 40 are joined together to form the curved portion 38. The plurality of metal plates 40 can be joined by welding, for example.

According to the bellmouth manufacturing method shown in FIG. 12 having the above-described configuration, a plurality of metal plates 40 arranged in the circumferential direction around the axis line 13 are joined to each other, so that the bellmouths 1A, 1B, 1F can be easily manufactured.
And the manufacturing method of the pump 3a can employ | adopt the manufacturing method of the bellmouth shown in FIG. In this case, the bell mouths 1A, 1B, and 1F are joined to the outer casing 5. However, since the bell mouths 1A, 1B, and 1F can be easily manufactured, the pump 3a can also be easily manufactured.

The bellmouth manufacturing method shown in FIG. 13 can be applied to the manufacturing of bellmouths 1C to 1E, and compared with the bellmouth manufacturing method shown in FIG. Are further provided.
In the taper part preparation step S3, a taper part 44 separate from the bending part 38 is prepared. The taper portion 44 is prepared and prepared by curving a metal plate and joining both ends of the plate by welding, for example.

  In the taper portion joining step S4, the tapered portion 44 prepared in the taper portion preparing step S3 and the curved portion 38 produced in the circumferential direction divided plate joining step S2 are joined together in the axial direction. The taper portion 44 and the curved portion 38 can be joined by, for example, welding or flange connection.

  According to the bellmouth manufacturing method shown in FIG. 13 having the above-described configuration, the plurality of metal plates 40 arranged in the circumferential direction around the axis line 13 are joined to each other, whereby the bellmouths 1C to 1E are joined. The curved portion 38 can be easily manufactured. Further, a tapered portion 44 that is separate from the curved portion 38 can be easily manufactured. As a result, according to the bell mouth manufacturing method shown in FIG. 13, the bell mouths 1C to 1E can be easily manufactured.

  And the manufacturing method of the pump 3a can employ | adopt the manufacturing method of the bellmouth shown in FIG. In this case, the bell mouths 1C to 1E are joined to the outer casing 5, but since the bell mouths 1C to 1E can be easily manufactured, the pump 3a can also be easily manufactured.

The bell mouth manufacturing method shown in FIG. 14 is applicable to the manufacturing of the bell mouth 1G, and when compared with the bell mouth manufacturing method shown in FIG. A spinning process S5 is provided instead of the plate joining process S2.
In the spinning process S5, as shown in FIG. 15, the curved portion 38 is formed by forming a metal cylinder 48 by spinning process. The cylinder 48 has, for example, a hollow truncated cone shape. In the spinning process, the cylindrical body 48 can be formed into a desired shape by pressing the processing jig 50 such as a roller against the cylindrical body 48 while rotating the cylindrical body 48.
The cylindrical body 48 can be manufactured by curving a metal plate material and joining both ends of the plate material, for example, by welding, like the tapered portion 44. In FIG. 15, the code | symbol 52 has shown the junction part of the board | plate material.
And in taper part joining process S4, the curved part 38 obtained by spinning process S5 is joined to the taper part 44 prepared by taper part preparation process S3 in an axial direction. The taper portion 44 and the curved portion 38 can be joined by, for example, welding or flange connection.

According to the bell mouth manufacturing method shown in FIG. 14 having the above-described configuration, the curved portion 38 included in the peripheral wall 30 is formed by spinning, whereby the inner surface of the curved portion 38 can be smoothed, Flow separation can be prevented. On the other hand, even if the peripheral wall 30 includes the tapered portion 44, depending on the position of the tapered portion 44 in the axial direction, the influence of the tapered portion 44 on the fluid flow is small, and the fluid flows smoothly in the bell mouth 1G. Can do.
Further, since it is not necessary to form the entire peripheral wall 30 by spinning, the bell mouth 1G can be easily manufactured.
And the manufacturing method of the pump 3a can employ | adopt the manufacturing method of the bellmouth shown in FIG. In this case, the bell mouth 1G is joined to the outer casing 5, but since the bell mouth 1G can be easily manufactured, the pump 3a can also be easily manufactured.

The present invention is not limited to the above-described embodiments, and includes forms obtained by changing the above-described embodiments and forms obtained by combining these forms.
For example, the fluid machine 3 to which the bellmouths 1A to 1G are applied is not limited to the pump 3a, and the fluid sucked and delivered by the fluid machine 3 is not limited to liquid but may be gas. . For example, the fluid machine 3 may be a fan, blower or compressor for gas. Therefore, the fluid machine 3 only needs to have at least a main casing, an impeller accommodated in the main casing, and a suction casing connected to the main casing, and the shape of the main casing and the impeller is particularly limited. There is no.

1,1A, 1B, 1C, 1D, 1E, 1F, 1G Bell mouth (suction casing)
3 Fluid machine 3a Circulating water pump 5 Outer casing (main casing)
7 Inner casing 9 Impeller 11 Rotating shaft 13 Axis 15 Support member 17 Hub 19 Blade 21 Flow path 23 Bending pipe 25 Joint 27 Drive shaft 30 Peripheral wall 32 First opening end 34 Second opening end 36 Flow path 38 Curved portions 40, 40a , 40b, 40c Plate (circumferential dividing plate)
41a One end of the plate 41b The other end of the plate 41c The side edges 42, 42a, 42b, 42c of the plate
44, 44a, 44b Tapered portion 45 Joining portion 46 Joining portion 48 Cylindrical body 50 Processing jig 52 Joining portion

Claims (10)

An annular first opening end, an annular second opening end that is spaced apart from the first opening end in the axial direction along the axis and has a smaller diameter than the first opening end, and the first opening end; Comprising a peripheral wall having a flow path extending between the second open ends;
The peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a part of the region in the axial direction;
The bell mouth, wherein the bending portion is constituted by at least a part of a plurality of metal plates arranged in a circumferential direction around the axis. The bell mouth according to claim 1, wherein joints between the plurality of metal plates extend in a radial direction orthogonal to the axis. The bell mouth according to claim 1, wherein a seam between the plurality of metal plates extends spirally around the axis. The peripheral wall further includes at least one taper portion made of metal in a region different from the curved portion in the axial direction,
4. The bell mouth according to claim 1, wherein the at least one taper portion has a straight cross-sectional shape inclined with respect to the axis in a cross section including the axis. 5. The bell mouth according to claim 4, wherein the curved portion and the at least one taper portion are configured by the plurality of metal plates. A main casing;
An impeller disposed in the main casing;
A bell mouth constituting a suction casing connected to the main casing, and
The bell mouth is
A ring-shaped first opening end, a second opening end located on the main casing side in the axial direction along the axis line than the first opening end, and having a smaller diameter than the first opening end; A peripheral wall having a flow path extending between one open end and the second open end;
The peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a part of the region in the axial direction;
The said curve part is comprised by at least one part of the some metal board arranged in the circumferential direction around the said axis line, The pump characterized by the above-mentioned. A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
In the method for manufacturing a bell mouth, the peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a partial region in the axial direction.
A circumferentially divided plate preparing step of preparing a plurality of metal plates arranged in the circumferential direction around the axis;
A bellmouth manufacturing method comprising: a circumferentially divided plate joining step of forming the curved portion by joining the plurality of metal plates to each other. A main casing;
An impeller disposed in the main casing;
A bell mouth constituting a suction casing connected to the main casing, and
The bell mouth is
A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
In the method for manufacturing a pump, the peripheral wall includes a curved portion having a curved cross-sectional shape in a cross section including the axis in at least a partial region in the axial direction.
A circumferentially divided plate preparing step of preparing a plurality of metal plates arranged in the circumferential direction around the axis;
And a circumferentially divided plate joining step for forming the curved portion by joining the plurality of metal plates to each other. A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
The peripheral wall is
The peripheral wall is located in at least a part of the region in the axial direction, and has a curved portion having a curved cross-sectional shape in a cross section including the axial line;
At least one tapered portion that is located in a region different from the curved portion in the axial direction and has a straight cross-sectional shape that is inclined with respect to the axial line in a cross section including the axial line;
A manufacturing method of bell mouth, comprising:
A manufacturing method of a bell mouth, comprising: a spinning step of forming a curved portion by forming a metal cylinder by spinning. A main casing;
An impeller disposed in the main casing;
A bell mouth constituting a suction casing connected to the main casing, and
The bell mouth is
A ring-shaped first opening end; a second opening end spaced apart from the first opening end in the axial direction along the axis and having a smaller diameter than the first opening end; and the first opening end and the second opening end Comprising a peripheral wall having a flow path extending between the open ends;
The peripheral wall is
A curved portion located in at least a part of the axial direction and having a curved cross-sectional shape in a cross section including the axial line;
At least one tapered portion that is located in a region different from the curved portion in the axial direction and has a straight cross-sectional shape that is inclined with respect to the axial line in a cross section including the axial line;
A method for manufacturing a pump, comprising:
A pump manufacturing method comprising a spinning step of forming a curved portion by forming a metal cylinder by spinning.

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