JP2016148306A - Guide body and pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guide body that has high energy efficiency in a wide operating range, and a pump device.SOLUTION: A guide body is arranged concentrically with an impeller, and guides fluid attracted in association with the rotation of the impeller. The guide body comprises: case parts that define a cylindrical flow passage; and a plurality of guide vane parts arranged in the cylindrical flow passage to spirally partition the cylindrical flow passage. In at least one of the plurality of guide vane parts, an end part on the inflow side of the fluid is formed in a stepped shape of which the outer peripheral side in the cylindrical flow passage is long and of which the inner peripheral side is short.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a guide body and a pump device.

  Conventionally, multistage pumps have been widely used to transfer fluids. The multi-stage pump is configured such that a plurality of impellers arranged along a drive shaft are accommodated in a guide body that defines a fluid flow path. The guide body spirally guides and rectifies the fluid boosted by the impeller, and transfers the fluid to the next stage impeller. In a multistage pump, a desired head can be obtained by changing the number of stages of the impeller and the guide body.

JP-A-6-323291

  In general, in a pump device such as a multistage pump, the blade angle of the guide body is designed so that the energy efficiency becomes the highest when operating at a predetermined rated discharge amount. For this reason, if the operating discharge amount increases or decreases from the rated discharge amount, the flow of fluid and the blade angle of the guide body do not match, and the amount of flow impeded by the guide blade on the guide body inflow side increases, and the pump device The energy efficiency of is reduced. In particular, when the operation discharge amount increases, the flow is greatly hindered on the inner peripheral side of the guide blade portion. However, there are many cases where the pump device is used with a discharge amount that is increased or decreased with respect to the rated discharge amount depending on the working environment or the needs of the user, and it is desired that the energy efficiency is high in a wide discharge amount region.

  This invention is made | formed in view of the said subject, and it aims at proposing the guide body and pump apparatus with high energy efficiency in a wide driving | operation area | region.

The guide body of this invention is a guide body which is arrange | positioned concentrically with an impeller and guides the fluid attracted with rotation of an impeller. The guide body includes a case section that defines a cylindrical flow path, and a plurality of guide blade sections that are arranged in the cylindrical flow path and that divide the cylindrical flow path in a spiral manner. An end portion on the fluid inflow side in at least one of the plurality of guide blade portions is formed in a stepped shape having a long outer peripheral side and a short inner peripheral side in the cylindrical flow path.
According to this guide body, when the amount of fluid attracted with the rotation of the impeller is relatively small, most of the fluid is guided by the extending portion that is a long portion. On the other hand, when the amount of fluid to be attracted is relatively large, most of the fluid is guided through the recess that is a short portion. For this reason, energy efficiency can be made high in a wide driving | operation area | region.

Moreover, the recessed part which is a short part of the edge part formed in the step shape may form a boundary part with the extension part which is a long part of the edge part formed in the step shape in a curved line shape.
In this way, when the amount of fluid attracted is large, the energy loss of the fluid guided through the recess can be reduced.

  Further, the end portion formed in a step shape is formed in a step shape in which the outer peripheral side is longer than the radial center in the cylindrical flow path and the inner peripheral side is shorter than the radial center in the cylindrical flow path. Also good.

  Further, the case portion may define the flow path so that the diameter thereof becomes narrower from the fluid inflow side toward the outflow side.

The pump device of the present invention includes the above-described guide body of the present invention and an impeller arranged concentrically with the guide body and attracting fluid to the guide body.
Also with this pump device, the same effect as the guide body of the present invention can be obtained.

  Moreover, you may further provide the power source which rotates an impeller.

It is a longitudinal section showing the multi stage pump of this embodiment typically. It is an external view which shows the guide body of this embodiment. It is a perspective view which shows the AA cross section in FIG. It is an AA view which shows the AA cross section in FIG. It is a BB view which shows the BB cross section in FIG. It is a figure which shows the guide wing | blade part 280 in FIG. It is a perspective view which shows one guide wing | blade part 280. FIG. It is a schematic diagram explaining the main movement of the fluid when the discharge amount of a pump is comparatively small. It is a schematic diagram explaining the main movement of the fluid when the discharge amount of a pump is comparatively large. (A) is a figure which shows the lift curve and efficiency curve with respect to the discharge amount, (B) is a figure which shows the guide loss lift with respect to the discharge amount.

  Hereinafter, a pump device and a guide body according to an embodiment of the present invention will be described with reference to the drawings. Although the following embodiment demonstrates the guide body applied to a multistage pump and a multistage pump as an example, it is not restricted to this.

  FIG. 1 is a longitudinal sectional view schematically showing the multistage pump of the present embodiment. In FIG. 1, bold arrows schematically show the flow of fluid. As shown in FIG. 1, the multistage pump 10 includes a motor 100 as a power source and a pump unit 200 attached to an upper portion of the motor 100.

  The motor 100 is connected to an external power source (not shown) via an electric cable 102. The drive shaft 104 of the motor 100 is connected to the main shaft 230 of the pump unit 200 via the joint 106. As long as the motor 100 can rotate the main shaft 230 of the pump unit 200, any motor 100 may be used. Since the motor 100 does not form the core of the present invention, the description of the detailed configuration is omitted.

  The pump unit 200 includes a suction case 210, a discharge case 220, a main shaft 230, an impeller 240, and a guide body 250.

  The suction case 210 is provided in the upper part of the motor 100 and is arranged as the lowest stage of the pump unit 200. The suction case 210 is fixed to the motor 100 by fastening a lower assembly portion 212 and the case 108 of the motor 100 with screws 214. The suction case 210 is formed in a substantially cylindrical shape, and a suction port 216 for sucking fluid is formed in the upper portion of the assembly portion 212. The assembly part 252 of the guide body 250 is fastened to the assembly part 218 at the upper part of the suction case 210 by a screw 253, and the guide body 250 is fixed.

  The discharge case 220 is provided on the upper portion of the guide body 250 and is disposed as the uppermost stage of the pump unit 200. The discharge case 220 is fixed to the guide body 250 by a lower assembly portion 222 and an assembly portion 254 of the guide body 250 being fastened by screws 255. The discharge case 220 is formed in a substantially cylindrical shape, and the upper assembly portion 224 is attached to a discharge pipe (not shown). The discharge case 220 includes a check valve 226 that prevents the fluid from flowing backward.

  The main shaft 230 is connected to the motor 100 through the joint 106 and is inserted through the suction case 210 and the guide body 250. The main shaft 230 is supported by a bearing sleeve 268 of the guide body 250. A plurality of impellers 240 are attached to the main shaft 230, and the plurality of impellers 240 rotate as the main shaft 230 rotates.

  The impeller 240 has a cylindrical insertion portion for inserting the main shaft 230 and a plurality of blades attached to the outer peripheral surface of the insertion portion. The impeller 240 rotates integrally with the main shaft 230 and pumps fluid from the upstream (lower in the figure) to the downstream (upper in the figure) by a plurality of blades.

  The guide body 250 is made of metal or resin. In this embodiment, the guide body 250 accommodates the main shaft 230 and the impeller 240 and defines a fluid flow path. The guide body 250 includes a liner ring 258 between the guide body 250 and the impeller 240 in order to prevent backflow of fluid. The guide body 250 has assembly parts 252 and 254 on the upper and lower sides, and can be fixed to the suction case 210 and the discharge case 220. The guide body 250 and the impeller 240 are combined in a single stage, so that a plurality of stages are provided. Can be stacked (in the example of FIG. 1, two stages are stacked).

  2 is an external view showing a one-stage guide body of the present embodiment, FIG. 3 is a perspective view showing a cross section AA in FIG. 2, and FIG. 4 is a cross section taken along the line AA in FIG. It is an AA view shown. 5 is a BB view showing a BB cross section in FIG. 2 to 5, the assembly parts 252 and 254 are omitted. In FIG. 5, thick arrows schematically indicate the flow of fluid.

  The guide body 250 includes an inner case portion 260 that defines the inner wall of the flow channel, an outer case portion 270 that defines the outer wall of the flow channel, and a plurality of guide wing portions 280 that connect the inner case portion 260 and the outer case portion 270. And comprising. The inner case portion 260, the outer case portion 270, and the guide wing portion 280 may be integrally formed by, for example, metal casting, or may be separately formed and connected.

  The inner case portion 260 has a bearing sleeve 268 into which the main shaft 230 is inserted. As shown in FIG. 5, the outer wall surface of the inner case portion 260 is formed in a substantially cylindrical shape whose diameter decreases toward the top. The outer case part 270 includes a space having a shape corresponding to the outline of the inner case part 260 so that a flow path is defined between the outer case part 270 and the inner case part 260. That is, the outer case part 270 is formed in a hollow shape, and the inner wall surface of the outer case part 270 is formed in a substantially cylindrical shape whose diameter decreases toward the upper side. The inner case portion 260 and the outer case portion 270 are spaced apart from each other, thereby defining a cylindrical flow path Fc through which a fluid attracted from the impeller 250 passes.

The inner case portion 260 and the outer case portion 270 are connected by a plurality of (seven in this embodiment) guide blade portions 280 in a state of being separated from each other. The plurality of guide wing portions 280 are arranged in a cylindrical flow path Fc with an equal positional relationship in the circumferential direction (see FIGS. 3 and 4), and are each formed in a plate shape having a smooth curved plate surface. Yes. FIG. 6 is a view showing the guide blade portion 280 with the inner case portion 260 and the outer case portion 270 in FIG. 4 omitted, and FIG.
It is a perspective view which shows the sheet | seat guide wing | blade part 280. FIG. 6 and 7, the alternate long and short dash line schematically shows the main flow of the fluid when the discharge amount is relatively small, and the thick line shows the fluid flow when the discharge amount is relatively large. The main flow is schematically shown.

  As shown in FIGS. 5 to 7, the guide wing wing 280 divides a cylindrical flow path Fc defined by the inner case portion 260 and the outer case portion 270 by a plate surface while rotating in the circumferential direction. Are arranged to be. The guide blade 280 has a plate surface substantially perpendicular to the axial direction of the main shaft 230 at the lower end (end on the inflow side of the flow path), and a plate surface at the upper end (end on the outflow side of the flow path). It is provided so as to be substantially parallel to the axial direction of the main shaft 230. Thereby, the guide wing | blade part 280 partitions so that the space demarcated by the inner side case part 260 and the outer side case part 270 may become a some spiral flow path.

  The lower end portion of the guide wing portion 280 is formed in a stepped shape having a long outer peripheral side (side closer to the outer case portion 270) and a shorter inner peripheral side (side closer to the inner case portion 260 and the main shaft 230). That is, the inner peripheral side of the lower end portion of the guide wing portion 280 is cut away. Hereinafter, a long part on the outer peripheral side is referred to as an extending part 282 and a short part on the inner peripheral side is referred to as a concave part 284. In the present embodiment, the extending portion 282 and the recessed portion 284 are such that the outer peripheral side from the center is the extending portion 282 and the inner peripheral side from the center is the recessed portion 284 with respect to the radial direction that is perpendicular to the axial direction of the main shaft 230. It is formed (Wa = Wb in FIG. 6). The extended portion 282 is formed such that a boundary portion 283 with the recessed portion 284 is substantially perpendicular, and the recessed portion 284 has a boundary portion 285 with the extended portion 282 formed in a smooth curved surface. In this embodiment, as an example, the boundary portion 285 of the recess 284 with the extending portion 282 has a half (Wf / 2) of the width Wf of the flow path when viewed along the axial direction of the main shaft 230. It is formed in a curved surface having a radius of curvature.

  FIG. 8 is a schematic diagram illustrating the main movement of the fluid when the discharge amount of the pump is relatively small, and FIG. 9 illustrates the main movement of the fluid when the discharge amount of the pump is relatively large. It is a schematic diagram to do. Note that the alternate long and short dash line in FIG. 8 and the thick line in FIG. 9 indicate the movement of the fluid without considering the movement around the main axis 230. In the multistage pump 10 of the present embodiment, when the main shaft 230 rotates by the power from the motor 100, the impeller 240 rotates integrally with the main shaft 230, and the fluid is attracted upward by the plurality of blades of the impeller 240. The fluid attracted by the impeller 240 is rectified by being guided spirally by the guide blade portion 280. Then, the fluid that has passed through the flow path inside the guide body 250 is guided as it is into the subsequent impeller 240 or the discharge case 2320. Thereby, the multistage pump 10 can transfer a fluid.

  Here, the fluid attracted by the impeller 240 tends to be guided upward (downstream) through the outer peripheral side under the influence of the secondary flow inside the impeller 240 when the discharge amount of the pump is relatively small. There is. On the other hand, when the discharge amount of the pump is relatively large, it tends to be guided upward (downstream) through the inner peripheral side which is a close path. On the other hand, the lower end portion (end portion on the fluid inflow side) of the guide wing portion 280 of the present embodiment has an extended portion 282 formed on the outer peripheral side, and has a long flow path (guide wing portion). The distance guided by 280 is long), and on the inner peripheral side, the recess 284 is formed and the flow path is shortened (the distance guided by the guide blade 280 is shortened). For this reason, when the discharge amount of the pump is relatively small, as shown in FIG. 8, most of the fluid is guided by the extending portion 282, and the fluid can be guided more accurately (backward). On the other hand, when the discharge amount of the pump is relatively large, as shown in FIG. 9, most of the fluid passes through the recess 284 and does not hinder the flow of the fluid. Thereby, the energy efficiency of the multistage pump 10 can be made high in a wide operation region.

FIG. 10A is a diagram showing a lift curve and an efficiency curve with respect to the discharge amount of the multistage pump, and FIG. 10B is a diagram showing a guide loss with respect to the discharge amount of the multistage pump. Here, in FIGS. 10A and 10B, the solid line is a graph of the present embodiment in which the lower end portion of the guide wing portion 280 is formed in a step shape, and the broken line is the lower end portion of the guide wing portion 280. It is a graph of the comparative example in which the recessed part 284 is not formed in FIG. As shown in FIG. 10A, in the multistage pump 10, the angle of the guide blade portion 280 is designed so that the specific discharge amount is rated Md and the efficiency is the highest. The flow of the fluid and the angle of the guide blade 280 are not matched, and the energy efficiency is lowered. However, in the multistage pump of the present embodiment, as shown in FIG. 10B, the lower end portion of the guide blade portion 280 is formed in a step shape, so that when the discharge amount is large, compared to the conventional multistage pump. The guide loss due to passing through the inside of the guide body 250 is reduced. Thereby, as shown to FIG. 10 (A), in the multistage pump 10 of this embodiment, when the amount of discharge is large, the fall of efficiency can be suppressed compared with the multistage pump of a comparative example (high efficiency). it can). Moreover, in the multistage pump 10 of this embodiment, when the discharge amount is small, there is almost no difference in energy efficiency from the multistage pump of the comparative example, and there is almost no difference in the head in the range of all discharge amounts. That is, the multistage pump 10 of this embodiment can improve the energy efficiency when the discharge amount is large without changing the head. The lift, efficiency, and guide loss with respect to the discharge amount were the same as those shown in FIGS. 10A and 10B even when the number of stages of the guide body 250 and the impeller 240 was changed. .

  The multi-stage pump 10 of the present embodiment described above is connected to the inner case portion 260 and the outer case portion 270 that define the cylindrical flow path, and the cylindrical flow path Fc by connecting the inner case section 260 and the outer case section 270. And a guide wing portion 280 that divides the shape into a spiral shape. And the lower end part (end part of the fluid inflow side) of the guide wing | blade part 280 is formed as the extended part 282 where the outer peripheral side is long, and is formed as the recessed part 284 where the inner peripheral side is short. Thereby, when the amount of fluid attracted with the rotation of the impeller 240 is relatively small, most of the fluid is guided by the extending portion 282. Also, when the amount of fluid attracted is relatively large, most of the fluid is guided through the recess 284. For this reason, energy efficiency can be made high in a wide driving | operation area | region.

  In addition, since the recess 284 of the guide blade 280 has a curved boundary 285 with the extension 282, the energy loss of the fluid guided through the recess 284 can be reduced. Further, since the inner case portion 260 and the outer case portion 270 of the guide body 250 define a flow path so that the diameter becomes narrower from the fluid inflow side to the outflow side, the fluid attracted by the impeller 240 is allowed to flow. It is possible to effectively rectify and guide downstream.

  The guide wing portion 280 described above is formed in a single stepped shape having the extending portion 282 and the concave portion 284, but may be formed in a plurality of steps.

  The concave portion 284 of the guide wing portion 280 is formed in a shape other than the curved surface, such as a substantially perpendicular boundary portion, although the boundary portion 285 with the extending portion 282 is formed in a curved shape. Also good. In addition, the extended portion 282 of the guide wing portion 280 is formed such that the boundary portion 283 with the concave portion 284 is formed at a substantially right angle, but the curvature radius is one half of the width Wf of the flow path (Wf / 2) It may be formed in a curved shape such as a curved shape. Further, when the boundary portions 283 and 285 of the extending portion 282 and the concave portion 284 are formed in a curved surface shape, the radius of curvature is not limited to one half (Wf / 2) of the width Wf of the flow path. What is necessary is just to form in a curved surface shape with a curvature radius.

  The guide blade portion 280 described above is formed so that the outer peripheral side from the center is the extended portion 282 and the inner peripheral side from the center is the concave portion 284 with respect to the radial direction that is perpendicular to the axial direction of the main shaft 230. However, the extending portion 282 and the recessed portion 284 are not limited to those divided at the center, and may be appropriately determined in width and ratio.

In the multistage pump 10 described above, the motor 100 is installed at the lower side, and the pump unit 2 is placed above the motor 100.
00 is installed, but the motor 100 may be installed above the pump unit 200. Further, the pump unit 100 is not limited to the vertical placement as shown in FIG. The multistage pump 10 may be used underwater or on land.

  In the guide body 250 described above, the seven guide wing portions 280 are provided between the inner case portion 260 and the outer case portion 270. However, the guide wing portions 280 have one to six or eight guide wing portions 280. It may be the above.

  In the guide body 250 described above, the lower end portions of all the guide blade portions 280 are formed in a step shape, but the lower end portion of at least one guide blade portion 280 may be formed in a step shape. For example, it is assumed that guide wings having lower ends formed in steps and guide wings not formed in steps are alternately provided, or alternately provided every predetermined number. Also good.

  The guide body 250 described above defines the cylindrical flow path Fc whose diameter decreases toward the downstream, but is not limited to this example, and may be anything. Moreover, although the above-mentioned guide body 250 shall accommodate the impeller 240, you may provide the case which accommodates the impeller 240 separately from the guide body 250. FIG.

  In the multistage pump 10 described above, the two-stage guide body 250 and the impeller 240 are provided. However, the guide body 250 and the impeller 240 may be used in only one stage, or three or more stages. May be provided.

  Although the embodiments of the present invention have been described above, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof. In addition, any combination of the embodiment and the modified example is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect can be achieved, and is described in the claims and the specification. Any combination or omission of each component is possible.

DESCRIPTION OF SYMBOLS 10 Multistage pump 100 Motor 102 Electric cable 104 Drive shaft 106 Joint 200 Pump part 210 Suction case 220 Discharge case 230 Main shaft 240 Impeller 250 Guide body 260 Inner case part 270 Outer case part 280 Guide blade part 282 Extend part 284 Concave part 285 Boundary Part

Claims (6)

A guide body that is arranged concentrically with the impeller and guides the fluid attracted as the impeller rotates;
A case portion that defines a cylindrical flow path;
A plurality of guide wings arranged in a plurality of the cylindrical flow path, and spirally dividing the cylindrical flow path;
With
The end portion on the fluid inflow side in at least one of the plurality of guide blade portions is formed in a stepped shape in which the outer peripheral side in the cylindrical flow path is long and the inner peripheral side is short,
Guide body. The guide body according to claim 1,
The concave portion, which is a short portion of the end portion formed in the step shape, has a curved boundary portion with the extended portion, which is a long portion of the end portion formed in the step shape,
Guide body. The guide body according to claim 1 or 2,
The end portion formed in the step shape is formed in a step shape in which the outer peripheral side is longer than the radial center in the cylindrical flow path and the inner peripheral side is shorter than the radial center in the cylindrical flow path. Yes,
Guide body. The guide body according to any one of claims 1 to 3,
The case portion defines a flow path so that the diameter becomes narrower from the fluid inflow side to the outflow side.
Guide body. A guide body according to any one of claims 1 to 4,
An impeller arranged concentrically with the guide body and attracting fluid to the guide body;
A pump device comprising: The pump device according to claim 5,
A power source for rotating the impeller;
Pump device.

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