JP2018028287A - Vortex-shaped pump and method for adjusting position of impeller in vortex-shaped pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vortex-shaped pump capable of adjusting performance of a pump without depending on an outer-diameter shape of a blade of an impeller.SOLUTION: A vortex-shaped pump includes an impeller, a main shaft configured to rotate the impeller, and a position adjustment member capable of adjusting a fixation position of the impeller to the main shaft in an axial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vortex pump and a method for adjusting the position of an impeller in the vortex pump.

  The vortex pump has a large gap between the lower edge of the impeller blade and the bottom surface of the pump casing that houses the impeller. Therefore, the vortex pump is widely used as a sewage / dirt pump that can prevent the occurrence of a clogging accident in the pump due to foreign matter.

  The structure of a conventional general vortex pump is shown in FIG. This includes a motor unit 2 that drives the main shaft 1 and a pump unit 3 that pumps water by the rotation of the main shaft 1. And between the pump part 3 and the motor part 2 is sealed with a mechanical seal 4 so that the pressure water of the pump part 3 does not leak to the motor part 2 side.

  In the motor unit 2, a rotor 5 that rotates integrally with the main shaft 1 and a stator 7 having stator windings are housed in a motor chamber 8. The motor chamber 8 is sealed in a watertight manner by a substantially cylindrical motor frame 10 opening upward and a motor cover 11 connected to the upper end of the motor frame 10, and an underwater cable 12 is connected to the upper part. ing.

  The main shaft 1 is rotatably supported via an upper bearing 13 attached to the motor cover 11 and a lower bearing 15 attached to the inner peripheral surface of the load side bracket 14 connected to the lower end of the motor frame 10. Furthermore, a handle 16 is provided on the upper surface of the motor cover 11 to suspend and move the pump to the spring site.

  On the other hand, the pump unit 3 includes a vortex pump impeller 41 having a plurality of blades 40 and connected to the tip of the main shaft 1 so as to rotate integrally therewith. The pump unit 3 includes a pump casing 50 that is divided into a lower casing 42 and an intermediate casing 30. The lower casing 42 has a discharge port 42 a and a suction port 42 b and forms a pump chamber 43. The impeller 41 is covered with a lower casing 42 and sucks spring water / sewage from the lower part and discharges it from the side. Here, the discharge curved pipe 24 is connected to the discharge port 42a.

  A wide gap C, which is a feature of the vortex pump, is provided between the lower edge of the blade 40 of the impeller 41 and the bottom surface of the lower casing 42 so that relatively large foreign matter can be easily discharged. It has become. The lower casing 42 is provided with a pump base 45 that allows the pump to stand on its own.

  The intermediate casing 30 connects the load side bracket 14 and the lower casing 42. The mechanical seal 4 is disposed in a mechanical seal chamber 31 defined by the intermediate casing 30 and the load side bracket 14. The mechanical seal chamber 31 is filled with oil that lubricates and cools the sliding surface of the mechanical seal.

As an example of a conventional vortex pump impeller 41, there is one in which a peripheral plate 61 is provided on the outer periphery of a main plate 60 as shown in FIG. Specifically, in the example of FIG. 8, the impeller 41 includes a main plate 60 and a substantially cylindrical main body that includes a peripheral plate 61 that extends along the outer periphery of the main plate 60 and substantially in the axial direction of the main shaft 1. And a plurality of blades 40 fixed to the main plate 60 and the peripheral plate 61 so as to extend from the inner peripheral side to the outer peripheral side inside the main body. The main plate 60 includes a hub portion 62 to which the main shaft 1 is attached and an annular shroud portion 63 formed around the hub portion 62. The hub portion 62 protrudes in the axial direction on the back side of the impeller 41 (in other words, on the motor side), and includes a mounting hole 64. In this example, the hub portion 62 has the same outer diameter on the back side and the front side of the impeller 41 (see FIG. 7), but the present invention is not limited to this, and the hub portion 62 has the impeller 41. There may be a case where the back side and the front side have different outer diameters. On the other hand, there is also a vortex pump impeller that has no peripheral plate (in other words, the outer peripheral side of the blade is open).

  FIG. 8A is a side view showing the tip of the main shaft 1. As shown in FIG. 8A, the outer diameter of the tip of the main shaft 1 is reduced so as to form an attachment shaft portion that is inserted into the attachment hole 64 of the hub portion 62. An annular surface (in other words, a stepped portion) 1c extending outward in the radial direction is formed between the small-diameter portion 1b having the reduced outer diameter and the large-diameter portion 1a adjacent to the small-diameter portion 1b. ing. On the back side of the impeller 41, the hub portion 62 is externally mounted on the mounting shaft portion 1b so that the end surface in the axial direction is in contact with the annular surface 1c (see FIG. 7). A keyway (not shown) is formed on the back side of the mounting hole 64, and a key 1d is formed on the outer peripheral surface of the mounting shaft portion 1b. Torque transmission from the main shaft 1 to the impeller 41 is performed by the engagement between the key 1d and the key groove. As shown in FIG. 7, a screw hole is formed at the tip of the mounting shaft portion 1b, and the mounting shaft portion 1b is fastened and fixed to the mounting hole 64 by a bolt or the like.

  In such an impeller 41, the sewage sucked from the suction port 42b passes between the blades 40 of the rotating impeller 41 and flows radially outward (in other words, the outer peripheral side of the impeller 41). It collides with the plate 61 and changes its direction in the axial direction. Thus, a vortex as shown by the arrow V in FIG. 7 is formed. The greater the strength of the vortex, the more efficiently the sewage is discharged from the discharge port 42a. Due to the large gap C formed between the lower surface of the blade 40 of the impeller 41 and the bottom surface of the lower casing 42, the vortex pump can easily discharge even a relatively large foreign object. Occurrence of blockage accidents at the can be reduced.

  Incidentally, in general, a pump performance curve is known as a means for indicating the performance of the pump. The performance curve of the pump shows the relationship between the lift, shaft power, pump efficiency, and the like with respect to the discharge amount. In order to adjust the performance of the pump, the outer diameter of the impeller blade is cut. 9A and 9B show a comparison of the performance curves of the pump when the outer diameter of the blade is processed in a vortex pump. 9A and 9B, when the pump performance before outer diameter processing and after outer diameter processing are compared, the pump efficiency is not significantly changed after outer diameter processing, and the pump efficiency and shaft power are reduced after the outer diameter processing. I understand that However, this method can be applied to an impeller without a peripheral plate, but cannot be applied to an impeller 41 having a peripheral plate 61 as shown in FIG.

  An object of one embodiment of the present invention is to provide a vortex pump capable of adjusting the performance of the pump without depending on the outer diameter processing of the impeller blades. Another object of the present invention is to provide a method for adjusting the performance of a vortex pump without depending on the outer diameter processing of the impeller blades.

According to an embodiment of the present invention, there is provided a vortex pump including an impeller, a main shaft that rotates the impeller, and a position adjustment member that can adjust a fixed position of the impeller relative to the main shaft in the axial direction. Is done. According to this configuration, the fixed position of the impeller in the vortex pump can be moved a predetermined distance forward in the axial direction using the position adjusting member. Therefore, the axial width of the blades can be cut to adjust the performance of the pump, and the fixed position of the impeller can be moved forward in the axial direction by the reduction in the width. Therefore, the pump performance can be adjusted without increasing the gap between the lower edge of the impeller and the bottom surface of the pump casing, that is, without reducing the pump efficiency.

  According to an embodiment of the present invention, the main shaft includes an attachment shaft portion that can be inserted into the attachment hole of the impeller, and an annular surface that extends radially outward with respect to the attachment shaft portion, and the position adjustment member. Has a through hole that can receive the mounting shaft portion, and is arranged around the mounting hole so as to be able to contact the annular surface.

  According to one embodiment of the present invention, the vortex pump is provided on the back side of the impeller and includes a closing member that closes a gap between the impeller and the pump casing, and the closing member is adjusted in position. It has an axial dimension that is substantially equal to the axial dimension of the member. According to this configuration, the gap formed on the back side of the impeller when the position of the impeller is moved forward in the axial direction can be closed by the closing member. Therefore, no extra fluid flow is generated on the back side of the impeller, and no loss occurs.

  According to one embodiment of the present invention, the closing member is fixed to the pump casing.

  According to one embodiment of the present invention, a method for adjusting the position of an impeller in a vortex pump, the step of cutting the impeller blades by a predetermined amount in the axial direction, and a shaft corresponding to the predetermined amount A step of preparing a position adjusting member having a through hole that has a directional dimension and can receive the mounting shaft portion of the rotating shaft, and the mounting shaft portion that is inserted through the through hole of the position adjusting member is passed through the mounting hole of the impeller There is provided a method including a step and a step of fixing the mounting shaft portion to the mounting hole. According to this configuration, the fixed position of the impeller in the vortex pump can be moved a predetermined distance forward in the axial direction. Therefore, the axial width of the blades can be reduced to adjust the performance of the pump, and the fixed position of the impeller can be moved forward in the axial direction by the reduction of the width. Therefore, the pump performance can be adjusted without increasing the gap between the lower edge of the impeller and the bottom surface of the pump casing, that is, without reducing the pump efficiency.

  According to an embodiment of the present invention, the method further includes disposing a closing member that closes a gap between the impeller and the pump casing on the back side of the impeller. With this configuration, the gap formed on the back side of the impeller when the position of the impeller is moved forward in the axial direction can be closed by the closing member. Therefore, no extra fluid flow is generated on the back side of the impeller, and no loss occurs.

  According to one embodiment of the present invention, the step of disposing the closing member includes fixing the closing member to the pump casing.

It is a figure which shows the structure of the vortex pump by one Embodiment of this invention. It is a figure explaining the cutting process of the impeller shown in FIG. It is the figure which expanded the principal part of FIG. It is a top view which shows the example of the shape of a position adjustment member. It is A1-A1 sectional view taken on the line of FIG. 3A. It is a top view which shows the example of the shape of a closure member. It is the A2-A2 line sectional view of Drawing 4A. It is sectional drawing which shows an example of an intermediate casing. It is a top view which shows the other example of the shape of a closure member. It is the A3-A3 sectional view taken on the line of FIG. 6A. It is a figure which shows the example of the structure of the conventional vortex pump. It is a figure which shows the example of the conventional impeller for vortex type pumps. It is a side view which shows the front-end | tip of a main axis | shaft. It is a figure which shows the performance comparison of the vortex pump before and behind the outer diameter process of a blade | wing. It is a figure which shows the performance comparison of the vortex pump before and behind the outer diameter process of a blade | wing.

  FIG. 1 is a view showing the structure of a vortex pump according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same part as the prior art example shown to FIGS. 7-8A, and the detailed description is abbreviate | omitted.

  In the present embodiment, as shown in FIG. 1, the pump unit 3 includes a plurality of blades 140, and the vortex pump impeller 141 connected to the tip of the main shaft 1 so as to rotate integrally therewith is provided. The basic structure is the same as in the prior art. The pump casing 50 is divided into an intermediate casing 130 and a lower casing 42, and the impeller 141 is covered by a lower casing 42 that has a discharge port 42 a and a suction port 42 b and is supported by a pump base 45. The pump chamber 43 is housed. The structure in which spring water, sewage and the like are sucked from the lower portion of the lower casing 42 and discharged from the side thereof is also the same as the conventional technology. However, as shown in FIG. 1A, the impeller 141 in this embodiment is cut in the axial direction for performance adjustment, and the axial width of the blade 140 is reduced by α as compared to the blade 40 of FIG. doing.

  FIG. 2 is an enlarged view showing a main part of the vortex pump of this embodiment. Similar to the above-described prior art, the main shaft 1 includes a small-diameter portion 1b that forms an attachment shaft portion that can be inserted into an attachment hole 164 formed in the hub portion 162, and a large-diameter portion 1a adjacent to the small-diameter portion 1b. ing. An annular surface (in other words, a stepped portion) 1c extending outward in the radial direction is formed between the large diameter portion 1a and the small diameter portion 1b. The attachment shaft portion 1b has a screw hole (reference numeral omitted) at the tip, and is fastened and fixed to the attachment hole 164 by a bolt or the like via a washer. In FIG. 2, the main shaft 1 is shown in cross section only in the portion of the mounting shaft portion 1 b inserted into the mounting hole 164. In the example of FIG. 2, the hub portion 162 has the same outer diameter on the back side and the front side of the impeller 141, but is not limited thereto, and the hub portion 162 is on the back side of the impeller 141. And the front side may have different outer diameters.

  Similarly to the prior art, a key 1d (see FIG. 8A) is formed on the outer peripheral surface of the mounting shaft portion 1b, and a key groove corresponding to the key 1d is formed in the mounting hole 164. Torque transmission from the main shaft 1 to the impeller 141 is performed by the engagement between the key 1d and the key groove. However, the engagement for torque transmission is not limited to the combination of the key 1d and the key groove. For example, the outer peripheral surface of the mounting shaft portion 1b may be chamfered, and the inner peripheral surface of the mounting hole 164 may be chamfered into a shape corresponding thereto.

  In this embodiment, the position adjusting member 200 is disposed between the large-diameter portion 1a of the main shaft 1 and the hub portion 162 of the impeller 141, and the back side (in other words, the motor side) of the shroud portion 163 of the impeller 141. The closing member 201 is disposed between the intermediate casing 130 and the intermediate casing 130. The position adjusting member 200 and the closing member 201 each have an axial dimension that is substantially equal to the reduction α of the axial width of the blade 140.

FIG. 3A is a plan view showing an example of the shape of the position adjusting member 200, and FIG.
FIG. As shown in FIGS. 3A and 3B, the position adjustment member 200 is a substantially cylindrical member, and includes a through hole 200a into which the attachment shaft portion 1b of the main shaft 1 can be inserted. In this embodiment, since the key 1d is formed on the mounting shaft portion 1b, the through hole 200a is formed with an axial groove 200b that can receive the key 1d of the mounting shaft portion 1b. The axial dimension of the position adjusting member 200 is set to be substantially equal to the decrease α of the axial width of the blade 140.

  As shown in FIG. 2, the position adjusting member 200 is disposed on the axial end surface of the hub portion 162 projecting to the back side of the main plate 160 and is disposed so as to contact the annular surface 1 c of the main shaft 1. However, the hub portion 162 does not have to have a form protruding toward the back side of the main plate 160 as shown. In other words, the entire back surface of the main plate 160 may be flat. The position adjusting member 200 may be disposed around the attachment hole 164 so as to contact the annular surface 1 c of the main shaft 1.

  By reducing the axial width of the blade 140, the flow rate of the fluid flowing inside the impeller 141 can be reduced. Therefore, the lift and shaft power of the impeller 141 can be reduced as in the case of processing the outer diameter of the blade. However, if the position adjusting member 200 is not provided, the gap C between the lower edge portion of the blade 140 that has been cut and the bottom surface of the lower casing 42 increases. The gap C is necessary for a vortex pump in order to easily discharge a relatively large foreign matter. However, if the gap C is too large, the pump efficiency becomes insufficient. By reducing the axial width of the blades 140, the gap C increases by the reduction amount α of the axial width of the blades, so that the pump efficiency is reduced accordingly. As a result, the head is greatly reduced with respect to the reduction in shaft power.

  In the present embodiment, by arranging the position adjusting member 200 between the large diameter portion 1a of the main shaft 1 and the hub portion 162 of the impeller 141, the fixed position of the impeller 141 in the vortex pump with respect to the main shaft 1 is determined. It can be moved a predetermined distance from the initial position before cutting forward in the axial direction (in other words, toward the bottom surface of the lower casing 42). By making the axial dimension of the position adjusting member 200 substantially equal to the reduction amount α of the axial width of the blade, the fixed position of the impeller 141 can be moved forward by the reduction amount α of the axial width. Therefore, the performance adjustment of the vortex pump can be performed without increasing the gap C between the lower edge portion of the impeller 141 and the bottom surface of the lower casing 42, that is, without greatly reducing the pump efficiency.

  In the case where the hub portion 162 has a form protruding toward the back side of the main plate 160 as shown in the figure, the protruding length is determined by the position of the mounting shaft portion 1b relative to the assumed axial position of the impeller 141, the key strength, and the like. Determined in consideration of

  4A is a plan view showing an example of the shape of the closing member 201, and FIG. 4B is a cross-sectional view taken along line A2-A2 of FIG. 4A. In the present embodiment, the closing member 201 is disposed around the hub portion 162 on the back side of the impeller 141 (in other words, around the back side protruding portion of the hub portion 162). Accordingly, the closing member 201 includes a through hole 201a through which the hub portion 162 can be inserted. However, when the hub portion 162 does not have a form protruding to the back side of the main plate 160, the closing member 201 is disposed around the position adjusting member 200, and the position adjusting member 200 is inserted into the through hole 201a. The Further, the closing member 201 has an axial dimension that is substantially equal to the axial dimension of the position adjusting member 200 (that is, the decrease α of the axial width of the blade 140).

When the fixed position of the impeller 141 is moved forward in the axial direction by the position adjusting member 200, the shaft of the blade 140 is arranged on the back side of the impeller 141 (between the intermediate casing 130 and the shroud portion 163 in this embodiment). A gap corresponding to the decrease α in the direction width is formed. In the present embodiment, the gap is closed by the closing member 201 having an axial dimension that is substantially equal to the axial dimension of the position adjusting member 200 (that is, substantially equal to the reduction α of the axial width of the blade 140). be able to. Therefore, an extra fluid flow is not generated on the back side of the impeller 141, and no loss occurs.

  In the example shown in FIG. 2, the closing member 201 is screwed to the intermediate casing 130. For this reason, as shown in FIG. 4A and FIG. 4B, the through-hole 201b which lets an attachment screw pass is formed in the closure member 201 at substantially equal intervals in the circumferential direction. Therefore, in this embodiment, the closing member 201 is fixed to the intermediate casing 130 by four mounting screws, but the number of mounting screws is not particularly limited.

  FIG. 5 is a cross-sectional view showing the intermediate casing 130 of FIG. As shown in FIG. 5, the intermediate casing 130 has a concave portion 132 that can receive the hub portion 162 of the impeller 141 at the central portion of the bottom surface 131, and the concave portion 132 is a central through hole 133 through which the main shaft 1 is inserted. have. An annular convex portion 134 is formed on the bottom surface 131 around the concave portion 132, and the closing member 201 is partially fitted in the axial direction inside the annular convex portion 134. Therefore, the inner diameter D of the annular convex portion 134 is set slightly larger than the outer diameter of the closing member 201. The closing member 201 can be easily positioned by the annular protrusion 134. However, the annular convex portion 134 for positioning is not necessarily provided. A screw hole 135 is formed in the mounting surface inside the annular convex portion 134. The screw hole 135 is formed at a position aligned with the through hole 201b of the closing member 201 in the axial direction.

  6A is a plan view showing another example of the shape of the blocking member, and FIG. 6B is a cross-sectional view taken along line A3-A3 of FIG. 6A. Unlike the example of FIGS. 4 and 4B, the closing member 301 of FIGS. 6A and 6B includes a through hole 301a through which the hub portion 162 can be inserted, but does not have a hole through which a mounting screw is passed. In this case, it is not necessary to form the screw hole 135 as shown in FIG. The closing member 301 can be fixed to the inside of the annular convex portion 134 of the bottom surface 131 of the intermediate casing 130 with an adhesive. In addition, or instead of this, the closing member 301 may be sandwiched between the bottom surface 131 of the intermediate casing 130 and the lower casing 42. In this case, an inner step that can contact the bottom surface of the closing member 301 can be formed on the side wall of the lower casing 42.

  Using the position adjusting member 200, for example, the position of the impeller 141 in the vortex pump can be adjusted by the following procedure to adjust the performance of the pump. In addition, the relationship between the axial cutting amount of the blade and the pump performance (for example, QH curve) is measured in advance by a test, and position adjusting members having several types of axial dimensions are prepared in advance. When the blade 140 of the impeller 141 is cut by a predetermined amount α in the axial direction, the position adjusting member 200 having an axial dimension corresponding to the predetermined amount α is prepared. The attachment shaft portion 1 b of the main shaft 1 is passed through the through hole 200 a of the position adjustment member 200. The attachment shaft portion 1b is inserted through the through hole 200a until the position adjusting member 200 contacts the annular surface 1c. The tip of the mounting shaft portion 1b after the insertion is passed through the mounting hole 164 of the impeller 141. Then, the attachment shaft portion 1b is fixed to the attachment hole 164 with a bolt or the like.

  Thus, the position adjusting member 200 can move the fixed position of the impeller 141 cut in the axial direction by a predetermined distance α forward in the axial direction. As a result, the gap C between the lower edge portion of the impeller 141 and the bottom surface of the lower casing 42 (and hence the bottom surface of the pump casing 50) is not increased, so that the pump efficiency is not significantly reduced. Performance adjustment can be performed.

Further, the procedure may include arranging the closing member 201. The closing member 201 may be disposed around the hub portion 162 on the back side of the impeller 141 so as to close a gap between the impeller 141 and the intermediate casing 130. Thereby, since an excess fluid flow is not produced on the back side of the impeller 141, the pump efficiency can be further stabilized. However, the closing member 201 is not necessarily arranged.

  The present invention can be widely applied to vortex pumps.

V ... Eddy current C ... Gap D ... Inner diameter 1 ... Main shaft 2 ... Motor part 3 ... Pump part 4 ... Mechanical seal 5 ... Rotor 7 ... Stator 8 ... Motor chamber 10 ... Motor frame 11 ... Motor cover 12 ... Underwater cable 13 ... Upper bearing DESCRIPTION OF SYMBOLS 14 ... Load side bracket 15 ... Lower bearing 16 ... Handle 1a ... Large diameter part 1b ... Small diameter part (mounting shaft part)
DESCRIPTION OF SYMBOLS 1c ... Annular surface 1d ... Key 24 ... Discharge curved pipe 30 ... Intermediate casing 31 ... Mechanical seal chamber 40, 140 ... Vane 41, 141 ... Vortex pump impeller 42 ... Lower casing 43 ... Pump chamber 45 ... Pump stand 50 ... Pump casing 60, 160 ... main plate 61, 161 ... peripheral plate 62, 162 ... hub portion 63, 163 ... shroud portion 64, 164 ... mounting hole 130 ... intermediate casing 131 ... bottom surface 132 ... concave portion 133 ... central through hole 134 ... annular convex Part 135 ... Screw hole 200 ... Position adjusting member 200a ... Through hole 200b ... Key groove 201, 301 ... Closing member 201a, 301a ... Through hole 201b ... Through hole

Claims (7)

Impeller,
A main shaft for rotating the impeller;
A position adjusting member that can adjust the fixed position of the impeller relative to the main shaft in the axial direction;
Vortex pump. The main shaft includes an attachment shaft that can be inserted into an attachment hole of the impeller, and an annular surface that extends radially outward with respect to the attachment shaft.
2. The vortex pump according to claim 1, wherein the position adjustment member has a through hole that can receive the attachment shaft portion, and is disposed around the attachment hole so as to be able to contact the annular surface. It is disposed on the back side of the impeller, and includes a closing member that closes a gap between the impeller and the pump casing,
The vortex pump according to claim 2, wherein the closing member has an axial dimension substantially equal to an axial dimension of the position adjusting member.   The vortex pump according to claim 3, wherein the closing member is fixed to the pump casing. A method for adjusting the position of an impeller in a vortex pump,
Cutting the blade of the impeller by a predetermined amount in the axial direction;
Preparing a position adjusting member having an axial dimension corresponding to the predetermined amount and having a through-hole capable of receiving a mounting shaft portion of a rotating shaft;
Passing the mounting shaft portion inserted through the through hole of the position adjusting member through the mounting hole of the impeller;
Fixing the mounting shaft portion to the mounting hole.   The method according to claim 5, further comprising disposing a closing member that closes a gap between the impeller and a pump casing on a rear side of the impeller.   The method of claim 6, wherein positioning the closure member includes securing the closure member to a pump casing.

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