JP2019039413A - Vertical shaft pump - Google Patents

Abstract

To provide a pump capable of efficiently cooling a motor.SOLUTION: The present invention relates to a pump configured to guide water from a suction port 1 to a discharge port in an upper part of the pump. The pump consists of a suction pipe part, a bend pipe part, a motor part and a chamber part. The pump comprises a main shaft 8 which extends in a substantially vertical direction inside of a suction pipe 12, an impeller 9 and a bearing part 10. The bend pipe part includes a discharge flange 15 which is directed to the side of a connection pipe part 13, and a first flange 17 which is positioned at an upper side of the suction port. The motor part includes a motor housing 18, a second flange 20 which is provided in a lower part of the motor housing, a heat exchanger 19 which is provided in a center of the lower part of the motor housing, and an output shaft 21 which is connected through the heat exchanger to a main shaft. The first flange or the second flange includes drain means such as a channel for draining water to the outside. In the pump, the chamber part consists of the first flange of the bend part, the second flange of the motor housing, a chamber cover, and a drain pipe 24 including an opening within a chamber.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vertical shaft pump.

  The pump pumps up the impeller by rotating it with a driving machine such as a motor. For this reason, the drive unit continuously generates heat during the pump operation, and thus needs to be cooled. There are roughly two types of cooling methods for driving machines used for pumps installed on land, such as air cooling by a fan that uses the rotation of a driving rotary shaft and water cooling that uses a cooler. Also, the normal drive is not sufficiently waterproof and cannot be driven if submerged.

  On the other hand, there is a demand for countermeasures against inundation of equipment such as pump buildings due to tsunamis, storm surges, local heavy rains, etc., which have occurred frequently in recent years. There are cases where installation of equipment equipment is done in high places, such as installing a new drive floor above the floor where the pump is installed, but the construction cost of the building has become very high.

JP 2001-304163 A Patent No. 5552402

  In order to solve the problems described in the background art, Patent Document 1 discloses a technique in which measures for waterproofing a motor around a pump facility are taken. However, even if the motor is waterproofed and the motor can be cooled with water around the submerged motor, the building structure that can normally circulate or drain the water that has flowed into the motor peripheral area has been considered. It does not flow, and it stays on the spot without flowing. Therefore, there is a possibility that the motor cannot be sufficiently cooled due to accumulation of generated heat in water flowing into the motor peripheral area and residual / accumulation of bubbles.

  On the other hand, Patent Document 2 discloses a pump technology in which a coolant is circulated inside a motor casing of a water-resistant motor, and a heat exchanger for cooling the coolant by pumping water is installed at a lower portion of the motor that is a part of the flow path. It is disclosed. However, in the disclosed technology, the water-resistant motor is attached to the pump in a watertight state, and the water contact surface with the pumped water, which is the lower surface of the heat exchanger, is located away from the main flow path above the main flow path of the pump. Since the pumped water in the vicinity of the exchanger is easy to stagnate, there is a problem that the cooling efficiency is low as in Patent Document 1. In addition, when the handled fluid is river water or sewage, it may contain suspended solids that have a lighter specific gravity than water or cloth waste that tends to stay in weak flow areas. This was one of the factors that reduced the cooling efficiency.

  In order to improve the efficiency of heat exchange, there is a technology to make the shape of the heat exchanger corrugated so as to increase the heat transfer area on the lower surface of the heat exchanger, but air or foreign substances etc. are accumulated or clogged in the corrugated groove as before. Once clogged, it is difficult to be discharged to the discharge port side, and the cooling efficiency may be further deteriorated.

  In the pump operation procedure, the suction pipe and elbow pipe are filled with air instead of fluid before the vertical pump is started. When the pump is started, most of the air in the suction pipe escapes to the outside from the air vent valve (see Fig. 14) installed near the discharge port, but a part of it stays on the elbow pipe, that is, the bottom of the heat exchanger. End up. In addition, the water pumped up by the impeller may contain fine bubbles, and most of the fine bubbles are discharged from the discharge port together with the pumped water, but some of this flows into the vicinity of the heat exchanger and exchanges heat. Accumulation on the lower surface of the vessel could result in deterioration of cooling efficiency.

  In this type of vertical shaft pump, a discharge cover is often provided between the main flow path and the sub flow path at the top of the elbow pipe to improve efficiency, but the water flow in the sub flow path is reduced during pump operation. Since the discharge of air becomes difficult, there is a problem that the discharge cover cannot be attached and the efficiency is lowered.

From the viewpoint of heat conduction in the vicinity of the heat exchanger, if an air reservoir (air layer) is interposed on the lower surface of the heat exchanger, when there is no air, water-air- The heat exchanger has two stages of heat transfer, increasing the thermal resistance element. The thermal conductivities at normal temperature and pressure of copper used in water, air, and general heat exchangers are 0.61 [W / (m · K)] and 0.026 [W / (m · K)], respectively. It is very different from about 370 [W / (m · K)]. In addition, the heat transfer coefficient between the air and the heat exchanger is considerably smaller than the heat transfer coefficient between the water and the heat exchanger. Therefore, when air is present, the heat transfer coefficient at the heat exchanger heat transfer surface is large. The heat exchange efficiency is greatly reduced.

When the vicinity of the heat exchanger has a watertight structure, the water (pumped water) stagnates in the vicinity of the heat exchanger, and the flow velocity directly below the heat exchanger becomes slower than the main flow velocity from the pump suction port to the discharge port. For this reason, the heat transfer coefficient on the lower surface of the heat exchanger is small, and when foreign matter, cloth dust, air, etc. accumulate as described above, it becomes a factor for further reducing the heat transfer rate of the heat exchanger, This reduces the efficiency of the exchange.

  The present invention has been made in view of the above situation, and by allowing a part of pumped water to flow out from between the first flange of the pump casing and the second flange of the motor unit, the present invention is proactive in the vicinity of the lower surface of the heat exchanger. A vertical shaft pump with a structure that can sufficiently cool the motor by increasing the efficiency of the heat exchanger by eliminating the accumulated air and foreign matters and improving the heat passage rate while generating water flow The purpose is to provide. In addition, in this specification, pumping water and water mean not only water but the liquid which is the object which a pump pumps up.

According to one aspect of the present invention, a vertical shaft pump that guides water from a suction port that opens downward to a discharge port that faces the side of the upper portion of the pump, and is connected to the suction pipe portion and the upper portion of the suction pipe portion. A bend pipe part, a motor part located at the upper part of the bend pipe part, and a chamber part,
The suction pipe portion includes a suction pipe, a main shaft extending in a substantially vertical direction in the suction pipe, an impeller fixed to the main shaft, and a bearing portion that supports the main shaft,
The bend pipe part includes a connection pipe part connected to the suction pipe, a discharge pipe directed to the side of the connection pipe part, a discharge flange, and a first flange located above the suction port. And having
The motor unit includes a motor housing, a second flange provided at a lower portion of the motor housing, a heat exchanger provided at the lower portion of the motor housing, and an output coupled to the main shaft through the heat exchanger. An axis, and
The first flange and / or the second flange has drainage means for discharging water to the outside, and at least a part of the outer periphery of the first flange and / or the second flange is in contact with drainage. And
There is provided a pump characterized in that the chamber part has a first flange of the bend pipe part, a second flange of the motor part, a chamber cover, and a drain pipe having an opening in the chamber part. The
The chamber cover may be composed of a plurality of members, for example, may be divided into two in the circumferential direction.

  The suction pipe part may have a bell part having a suction port opened at a lower part of the suction pipe, or may have a guide vane.

  The bend pipe part may have a discharge cover.

  The motor unit motor may use a water-resistant motor having an intercooling system that has an impeller inside and circulates a coolant inside the motor by the impeller.

  By providing a drainage means through which water and air can flow out, new water pumped up by the pump can be continuously brought into contact with the heat exchanger to exchange heat, and the pump can be cooled efficiently. Further, by providing the chamber, a part of the outside of the motor housing other than the heat exchanger can also contact and exchange heat with the waste water, so that the cooling efficiency is improved.

  The drainage means is a groove or the like that opens in at least one coupling surface of the first flange and / or the second flange. Further, the drainage means is a groove having a rectangular, semicircular or triangular cross-sectional shape, or an arbitrary uneven portion shape such as a polygonal column, cylinder, hemisphere formed on the first flange and / or the second flange surface. It may be a gap formed by

  Furthermore, grooves or parallel, radial, and wavy concave grooves or convex shapes that are drainage means may be formed, and the direction and directionality of the grooves and concave and convex shapes formed by them can be arbitrarily set.

For example, the pumping contact portion of the heat exchanger provided in the lower part of the motor housing in the vicinity of the drainage means may take a shape such as a fin shape, a wave shape, or a plurality of arbitrary protrusion shapes. Further, the concave portion and / or convex portion of the pumping contact portion of the heat exchanger has a polygonal pyramid, a cone, or a cone with a vertex near the rotation axis, with the vicinity of the rotation axis on the pump side and the outer peripheral side with the drainage means on the motor side. It can also be spherical. Moreover, even if it is not a smooth surface, it can also be made into the said substantially shape formed in step shape. By forming the heat exchanger of the motor in such a shape, it is possible to easily discharge air and light dust that are likely to collect near the rotation axis, which is in the vicinity of the apex.
In addition, when the surface formed by the concave and / or convex portions of the pumping contact portion of the heat exchanger or the stepped portion is inclined with respect to the rotation axis (main axis) direction, it is inclined toward the motor side. The same effect can be expected by forming the discharge means at the circumferential angle.

  The outer diameter of the first flange is larger than the outer diameter of the second flange, and the chamber cover includes a first surface extending from the side surface of the motor housing in an outer diameter direction, the first surface, and the first flange. You may have the 2nd surface extended from an upper surface.

  The outer diameter of the first flange is larger than the outer diameter of the second flange, and the chamber cover includes a ceiling surface located above the motor housing, and a second extending from the ceiling surface and the upper surface of the first flange. It may have a surface.

  The outer diameter of the first flange is larger than the outer diameter of the second flange, and the chamber cover has a first surface extending from the side surface of the second flange in the outer diameter direction, the first surface, and the first flange. You may have the 2nd surface extended from an upper surface.

  The outer diameter of the second flange is larger than the outer diameter of the first flange, and the chamber cover has a first surface extending from a side surface of the first flange in an outer diameter direction, the first surface, and the second flange. You may have the 2nd surface extended from the lower surface.

  The outer diameter of the second flange is larger than the outer diameter of the first flange, and the chamber cover includes a first surface extending in an outer diameter direction from the lower surface of the first flange, and the first surface and the second flange. You may have the 2nd surface extended from a lower surface.

  It is desirable that the water discharged into the chamber through the drainage means after heat exchange with the heat exchanger of the motor unit further cools at least a part of the motor unit.

  A drain pipe having an opening in the chamber and opened to the outside is provided. Further, the chamber-side opening of the drain pipe has an opening on the outer peripheral side or upper surface side of the chamber, or an opening extended from the lower surface side, and the opening of the drain pipe is located on the upper surface of the heat exchanger. It is desirable to install at a position higher than the upper part of the drainage means. That is, it is desirable that the drain pipe connecting the inside and the outside of the chamber portion is installed such that the chamber side opening of the drain pipe is higher than the upper surface of the heat exchanger or the upper portion of the drainage means. By disposing it high, the water level in the chamber is higher than the top of the heat exchanging part during operation, and the heat exchanging part is submerged, resulting in good heat exchanging efficiency. In addition, air contained in the drainage and light small dust can be discharged from the chamber.

  Further, it is desirable that the other opening of the drain pipe is located sufficiently above the liquid level in the suction water tank during normal operation. Reduces drainage resistance and increases water flow.

  In addition, when a bent portion is provided in the middle of the drain pipe, it is preferable to have a curvature and a space inner diameter that are as large as possible so that foreign matter is not caught at that portion. Specifically, a drain pipe that connects the inside and outside of the chamber portion. It is preferable that the bent portion of the drain pipe has a space larger than the narrowest gap length of the drain means or a space larger than the minimum inscribed sphere diameter of the space.

  Further, it is desirable that an inspection window is provided in the chamber portion at a position where the inside of the chamber portion and / or the opening of the drain pipe can be visually recognized. Further, the inspection window may be replaced with an inspection door that can be opened, and it is desirable that dust and the like can be removed inside the chamber. By installing these, maintenance is facilitated.

  Furthermore, it is desirable that the chamber part or the drain pipe is provided with an opening through which air can pass, and it is further desirable that the opening be provided at a position higher than the chamber part. Moreover, it is desirable to have a valve in the opening. Air can be extracted from the chamber, and cooling efficiency is improved. In particular, in the case of a pipe where the drain pipe passes through a position higher than the chamber, it is possible to easily remove the air by providing the valve for extracting air at a high position.

  In addition, it is desirable that the valve has a waterproof function that can operate even when submerged, and a valve with a waterproof function that can be remotely operated is employed.

  The drain pipe may be provided with a flow meter. By measuring the flow rate in the drain pipe with a flow meter, it is possible to monitor the clogging of the ditch, drain pipe and the operation status of the pump. Furthermore, in order to prevent the flowmeter from losing its function due to flooding on the pump installation floor, various types of flowmeters can be used, but it is desirable to have a signal output that can be observed remotely, and can be used even when flooded. It is preferable to select a waterproof type. A temperature sensor can be used instead of the flow meter. In this case, the operation status can be confirmed by comparing and monitoring the pumping water temperature and the drain pipe water temperature. As with the flow meter, it is preferable to select a waterproof temperature sensor such as a connector.

  In addition, a water-resistant motor having an intercooling system that has an impeller inside and circulates coolant through the impeller can be used for the motor of the motor unit, and a temperature sensor is provided in the coolant flow path. May be installed. By setting the upper limit or lower limit value of the temperature sensor output, it becomes possible to detect a cooling abnormality using a system that issues a warning, and it is possible to control or stop the pump system before an abnormally serious failure occurs. In addition, when a plurality of pump systems are used, it is possible to operate the entire pump system without degrading performance by adjusting the outputs of other pumps to perform cooperative operation.

A flow path branched from the drain pipe, a first valve provided downstream from the branch point of the drain pipe with the flow path, a second valve provided in the flow path, and provided in the flow path And a flushing pump provided. These are hereinafter referred to as flushing systems. The pump installation floor of the pump station is often unmanned, and it is preferable to use an electric type so that the valve can be opened and closed by operating or controlling it from the pump operation room or remotely, and the function of the electric valve is lost due to water on the pump installation floor. In order to prevent this, it is preferable to select a waterproof type when installing a valve or a flushing pump below the water level where flooding is assumed.
The first valve is preferably a gate valve, a ball valve, a funnel valve, or the like having a large valve opening section when the valve is opened, because pumped water containing foreign matter or the like always passes through the pump.

  When the drain pipe is clogged with foreign matter, etc., the first valve is closed, the second valve is opened, and water is sent to the drain pipe side through the flow path by the flushing pump. To reverse the water. By this water flow, foreign matter and the like can be returned to the chamber, and further returned to the main flow path through the drainage means and the sub flow pipe section. Moreover, it is desirable that the lower surface of the chamber and the lower surface of the drainage means have a surface that descends toward the opening with the sub-flow path of the drainage means, and the structure is such that water does not accumulate in the chamber during flushing and can be easily drained to the pump side. . Moreover, this structure can prevent a puddle (dead water) before starting the pump, and is also effective in preventing malodor.

Furthermore, the flushing pump is sufficiently higher than the pumping pressure of the sub-flow channel pipe in consideration of the pipe loss up to the sub-flow channel so that the flushing system can be used even when the vertical pump is in operation. It is preferable to select a pump capable of discharging pressure. The inner diameter of the drainage pipe is preferably larger than the particle size that can pass through the drainage means so that foreign matter or the like that has passed through the drainage means is not clogged in the drainage pipe. In many pump stations, there is a dust removal facility before water flows into the suction tank, and large foreign objects are removed by the dust remover. Therefore, the particle size of foreign matters contained in the water pumped up by the pump can be assumed based on the screen width of the dust remover as one standard.

The bend portion extending upward from the suction pipe side and forming a main flow path toward the side discharge flange has a first flange at the upper end opening of the suction pipe opening, There may be a main shaft or an output shaft penetrating from the pipe side in the first flange direction, and a second impeller may be attached to the main shaft or the output shaft. The second impeller generates a water flow from the lower side of the first flange toward the first flange, and by this water flow, water, air, and small foreign matters are efficiently discharged from the drainage means formed on the first and second flanges. Since it can be discharged, the cooling efficiency is improved.

The second impeller not only generates a water flow in the first flange direction, but also has a blade forming portion having a foreign matter crushing function in a part of the second impeller, so that the impeller and its fixed side facing each other It is good also as a structure which can cut a foreign material between. A rotary blade may be attached instead of the second impeller, and the water flow generation function may not be provided, and only the crushing function may be provided. In that case, the crushed foreign matter is discharged by the water flow generated by the pressure difference determined by the water pressure generated by the pump, the pressure in the chamber, the pressure at the drainage pipe opening, and the pipe resistance from the subflow pipe to the drainage pipe opening. It will be.

  In addition, if the opening diameter directly under the heat exchanger is reduced to be smaller than the inner diameter of the sub-flow pipe, the air and light dust that tend to collect at the center of the rotating shaft near the center of the heat exchanger are guided to the drainage means by the water flow at a high flow velocity, It can be discharged to the outside through the drain pipe.

  Needless to say, it is desirable that the pump equipment such as the driving device and the discharge valve be waterproof, remote operation control or observable specification that can be used even during flooding. It can be used as a drainage system that can be operated remotely by supplying drive power and control signals from outside.

  According to another aspect of the present invention, a vertical shaft pump for guiding water from a suction port opened downward to a discharge port facing a side of the upper part of the pump, the suction pipe unit being connected to the suction pipe unit upper part A bend pipe part, a motor part located at the upper part of the bend pipe part, and a chamber part. The suction pipe part includes a suction pipe, a main shaft extending substantially vertically in the suction pipe, and a main shaft. An impeller fixed to the main shaft, and a bearing portion that supports the main shaft, and the bend pipe part is connected to the suction pipe, and the discharge pipe is directed to the side of the connection pipe part. A suction pipe, a discharge flange, and a first flange located above the suction port, and the motor unit includes a motor housing, a second flange provided at a lower portion of the motor housing, A heat exchanger provided at a lower portion of the motor housing; An output shaft connected to the main shaft through an exchanger, and the chamber portion includes a first flange of the bend pipe portion, a second flange of the motor portion, the first flange, and the first flange. A spacer provided between the two flanges, a chamber cover, and a drain pipe having an opening in the chamber portion, and the water pumped up from the suction water tank from the first flange side to the first flange A pump is provided which is led between the second flange and discharged to the outside through the drain pipe.

  The chamber cover may be composed of a plurality of members divided in a direction orthogonal to the output shaft.

  The chamber cover may include a lower chamber cover that covers the first flange from the circumferential direction, and an upper chamber cover that covers the second flange from the circumferential direction.

  The chamber cover includes: a cylindrical portion that contacts the outer peripheral surfaces of the first flange and the second flange; a ceiling portion that extends inward from the upper portion of the cylindrical portion; and a bottom portion that extends inward from the lower portion of the cylindrical portion. And the lower surface of the outer periphery of the first flange is inclined so as to be higher toward the outer periphery, the upper surface of the outer periphery of the second flange is inclined so as to be lower as the outer periphery is reached, and the upper surface of the bottom is It may be inclined so as to become lower, and the lower surface of the ceiling part may be inclined so as to become lower toward the inside.

  A seal member may be provided between the first flange and the chamber cover and / or between the second flange and the chamber cover.

  The concave portion and / or convex portion of the pumping contact portion of the heat exchanger has a polygonal pyramid, cone or spherical surface in which the apex is located in the vicinity of the main shaft, the vicinity of the main shaft is located on the pump side, and the outer peripheral side where the drainage means is located Or a stepped shape.

Since a part of the pumped water can pass between the first flange of the bend pipe part and the second flange of the motor part in the pump, fresh pumped water is supplied to the heat exchanger provided near the second flange of the motor part. Supply, accumulated air and foreign matter can be discharged, the motor can be cooled efficiently, and abnormal operation stop due to overheating, reduction in motor efficiency, and increase in required power can be prevented.
In addition, since the water pumped up from the suction water tank is discharged from the first flange side to the chamber side through the drainage means, there is no need to provide a separate supply pipe. Therefore, there is an effect that a large flow rate is obtained and high heat exchange efficiency is obtained.

The pump schematic diagram concerning a 1st embodiment. The main part of the pump according to the first embodiment. AA sectional view of the 1st flange in Drawing 2 concerning a 1st embodiment. The AA sectional view of the flange which is a modification of Drawing 3A concerning a 1st embodiment. AA sectional view of a flange which is another modification of Drawing 3A concerning a 1st embodiment. AA sectional view of a flange which is another modification of Drawing 3A concerning a 1st embodiment. The figure of the vicinity of the heat exchanger 19 seen from the impeller 9 side according to the first embodiment. The figure which shows the example of the drainage means. The figure which shows the example of the drainage means. The figure which shows the example of the drainage means. The figure which shows the example of the drainage means. BB sectional drawing of the chamber cover which concerns on 1st Embodiment. The chamber part vicinity figure which is a modification of FIG. 1 and FIG. The chamber part vicinity figure which is a modification of FIG. The chamber part vicinity figure which is a modification of FIG. The chamber part vicinity figure which is a modification of FIG. FIG. 6B is a sectional view taken along line AA in FIG. 6B. The chamber part vicinity figure which is another modification of FIG. The chamber part vicinity figure which is another modification of FIG. The chamber part vicinity figure which is another modification of FIG. The chamber part vicinity figure which is another modification of FIG. FIG. 10B is a cross-sectional view of the first flange 17 in FIG. 10A. The perspective view which shows the example of the convex part 41. FIG. The perspective view which shows the example of the convex part 41. FIG. The perspective view which shows the example of the convex part 41. FIG. The perspective view which shows the example of the convex part 41. FIG. The perspective view which shows the example of the convex part 41. FIG. Sectional drawing of the upper chamber covers 52C and 52D divided into two. The figure which looked at the upper chamber cover 52 'from the bottom. The chamber part vicinity figure which is another modification of FIG. The chamber part vicinity figure which is another modification of FIG. The chamber part vicinity figure which is another modification of FIG. The chamber part vicinity figure which is another modification of FIG. FIG.

  Embodiments according to the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a schematic view of a pump according to the first embodiment, and FIG. 2 is a main part of the pump according to the first embodiment. This pump is, for example, a vertical shaft pump disposed in a drainage station, and is a pump that guides water from a suction port 1 that opens downward to a discharge port 2 that faces the side of the upper part of the pump, and a suction pipe portion 3; It comprises a bend pipe part 4 connected to the upper part of the suction pipe part 3, a motor part 5 located at the upper part of the bend pipe part 4, and a chamber part 6, and the suction pipe part 3 opens at the lower part of the suction pipe 12 The bell portion 7 having the suction port 1, the main shaft (rotation) shaft 8 extending substantially vertically in the suction pipe portion 3, the impeller 9 fixed to the main shaft 8, and the bearing portion that supports the main shaft 8. 10, a guide vane 11, and a suction pipe 12.

  The bend pipe part 4 includes a connection pipe part 13 connected to the suction pipe 12, a discharge pipe 14 directed to the side of the connection pipe part 13, a discharge flange 15, and a discharge cover 16. The motor unit 5 has an impeller (not shown) inside, and circulates the coolant in the motor unit 5 by the impeller, A water-resistant motor (not shown) having an intercooling system for exchanging heat with an external heat source in a part of the circulation path, a motor housing 18, a heat exchanger 19 provided at the lower part of the motor housing 18, and the motor housing 18 A lower flange, a heat exchanger 19 or a second flange 20 provided integrally with the lower portion of the motor housing 18 and the heat exchanger 19, and an output shaft 21 connected to the main shaft 8 through the heat exchanger 19 are provided. The first flange 17 has a drainage means 22 such as a water channel for discharging water to the outside at a part of the mating surface with the second flange 20. When the drainage means 22 is used, the first flange 17 The outer periphery of the two flanges 20 is in contact with the drainage, and the chamber part 6 includes the first flange 17 of the bend pipe part 4, the second flange 20 of the motor part 5, the chamber cover 23, and the chamber part 6. And a drain pipe 24 having an opening.

  It is desirable that the drain pipe 24 is provided with a flow meter 24b and a drain water temperature gauge (temperature sensor) 24c, and the connecting pipe portion 13 is provided with a pumped water temperature gauge (temperature sensor) 24d. By measuring the flow rate in the drain pipe 24 with the flow meter 24b, it is possible to monitor the clogging of the drainage means 22 and the drain pipe 24 and the operating state of the pump. Further, the operation status can be confirmed by comparing and monitoring the water temperature in the drain pipe 24 and the water temperature in the suction pipe 12 by the drain water temperature gauge 24c and the pumped water temperature gauge 24d.

  In general, a discharge valve is often provided in the piping after the discharge port 2, but only the discharge port 2 will be described here. Needless to say, the devices that can be driven or controlled, including this discharge valve, can be driven remotely by electric, air, and hydraulic pressures and should be waterproof, and can be operated and controlled even during flooding. Yes.

  The impeller 9 can be rotated by rotating the motor in the motor unit 5. At this time, the motor generates heat, and heat is transmitted to the heat exchanger 19 and the motor housing 18. On the other hand, due to the rotation of the impeller 9, water is sucked up from the suction port 1 and can be drained from the discharge port 2. At that time, a part of the water sucked up from the suction port 1 reaches the lower surface of the heat exchanger 19, cools the heat exchanger 19 by the heat exchange function of the heat exchanger 19, and as a result takes heat generated by the motor. Thereafter, the water is discharged into the chamber portion 6 through the drainage means 22 such as a groove, and further cools at least a part of the motor portion 5 such as the motor housing 18. It is also possible to improve the cooling effect by attaching fins to the motor housing 18 located in the chamber. The water that has entered the chamber is finally drained into the water tank on the suction side and the discharge side.

  3a and 3b are cross-sectional views of the first flange of FIG. The drainage means 22 is a groove 22a or the like that opens on the coupling surface of the first flange 17 and the second flange 20, and may be provided on the second flange side or both in addition to the groove formed by the first flange illustrated in the present example. Is possible. Further, as shown in FIGS. 3b1 and 3b2, the groove 22a may be asymmetric in the AA cross section of the first flange 17.

  FIG. 3 c is a view of the vicinity of the heat exchanger 19 as viewed from the impeller 9 side. A groove 19 a may be formed in the heat exchanger 19 according to the position of the drainage means 22.

In addition, the drainage means 22 has a shape in which the grooves 22a such as rectangular, semicircular, triangular, and wavy grooves (FIGS. 3d to 3g) and any irregularity shape formed on the two flange surfaces are combined on the surface. It is also possible to use the formed gap. Furthermore, the shape of the groove and the concavo-convex portion as the drainage means 22 can be arbitrarily set such as a parallel shape, a radial shape, and the direction and directionality of the groove and the gap. Moreover, there may be a plurality of types of irregularities such as a polygonal column such as a hexagonal column, a rectangular parallelepiped, a cylinder, and a hemisphere. As shown in FIG. 3 a, a hole 17 a for the chamber cover fixing bolt 25 (see FIG. 2) and a hole 17 b for the drain pipe 24 are formed in the first flange 17.

  4 is a cross-sectional view of the chamber cover of FIG. 2 taken along the line BB. The chamber cover 23 is formed with a through hole 23a for a chamber cover fixing bolt 25 (see FIG. 2). As shown in FIG. 2, when the chamber cover fixing bolt 25 passes through the through hole 23 a of the chamber cover 23 and is fastened with a nut from the screw hole of the first flange 17 and the back surface, the bolt is fastened through the through hole 17 a. .

  The drainage means 22 may be a radial groove installed on the coupling surface of the first flange 17 and the second flange 20. For example, the drainage means 22 has a groove of an arbitrary shape such as a radial or parallel groove in the recess of the first flange 17. This can also be realized by assembling a disk or another piece of spacer.

  After incorporating the groove of the separate piece, the shape of the drainage means and the arrangement of the pumping contact portion of the heat exchanger 19 in accordance with the direction of drainage by the inclined surface including the stepped shape of the groove direction and the concave and / or convex portions May be selected, which facilitates the discharge of air and light trash.

  As shown in FIG. 2, the outer diameter of the first flange 17 is larger than the outer diameter of the second flange 20, and the chamber cover 23 is a first surface extending in the outer diameter direction from the vicinity of the side surface of the motor housing 18. 26, the first surface 26, and a second surface 27 extending from the upper surface of the first flange 17.

  After the heat exchange in the heat exchanger 19 of the motor unit 5, the water discharged into the chamber unit 6 through the drainage means 22 is at least part of the motor unit 5, for example, the second flange of the motor housing 18. The outer periphery of 20 can be further cooled.

  The drainage pipe 24 is larger than the maximum opening diameter of the drainage means 22, and the inlet of the drainage pipe 24 is located at a position where the discharge pipe position of the bend pipe part 4 is removed as viewed from the top of the pump, preferably on the opposite side. The inlet of the drainage pipe 24 is located at a relatively upper part in the chamber part 6 and is located higher than the heat exchanger 19. That is, the drain pipe 24 is installed at a position where the opening on the chamber part 6 side is higher than the upper surface of the heat exchanger 19 or the upper part of the drainage means 22. Further, the opening may be provided with a filter such as a wire mesh for preventing foreign matter from entering.

Further, the drain pipe 24 is constituted by a straight pipe without a bent portion, passes through the first flange 17 from the chamber portion 6 side, further passes through the pump floor, and opens above the water surface during normal operation in the suction water tank. May be installed. When the bent portion is provided in the drain pipe 24, it is preferable that the bent portion has a curvature or a space inner diameter larger than the gap length of the drainage means 22 from the viewpoint of preventing clogging.
Furthermore, a waterproof valve 24 a may be installed in the drain pipe 24.

  The chamber cover 23 is provided with an inspection window 28 at a position where the inside of the chamber 6 and / or the opening of the drain pipe 24 can be visually confirmed. An inspection door that can be opened may be installed, and in that case, a door with high pressure resistance and high airtightness that can withstand pump water pressure is desirable.

  Further, an opening through which air can pass may be provided in the upper portion of the chamber cover 23. An air pipe 29 is connected to the opening, and a valve 30 with a waterproof function that is provided at a position higher than the chamber portion 6 and has a water resistance function capable of operating when submerged and can be remotely operated is provided. desirable. Furthermore, a waterproof water detection sensor (not shown) is installed in the middle of the piping. After the pump is driven, the opening and closing of the valve 30 is controlled using a water detection sensor as a trigger for a certain period of time, and the air remaining at the start of operation in the sub-flow pipe section 31, the drain means 22 and the chamber section 6 is discharged. Seal.

  Further, a water passage pipe through which water can pass is connected to the upper portion of the chamber cover 23, and a waterproof valve (not shown) having a water resistance function capable of operating when submerged in the middle of the pipe and remotely operable. May be installed. Further, a pump and a water pipe or a washing water tank are connected to the tip.

  When foreign matter is clogged in the vicinity of the drainage means 22 or the heat exchanger 19, the foreign matter is blocked by the temperature of the motor, the electric power, the cooling water temperature inside the motor, the flow meter 24b installed in the drain pipe 24, the thermometer 24c, etc. To detect.

  A thermocouple or a resistance temperature detector can be used for the thermometer, and it can also be input to the control device via a temperature transmitter. Moreover, an electromagnetic flow meter etc. can be utilized for a flow meter.

  After the detection, the valve 24a of the drain pipe 24 is closed, the pump connected to the water pipe is started, the valve (not shown) of the water pipe is opened, and the cleaning water is introduced into the chamber section 6, the drain means 22, the heat exchanger The water can be made to flow back to 19 and the foreign matter can be returned to the sub-flow channel pipe portion 31 and discharged from the main flow channel.

  A flow path branched from the drain pipe 24, a first valve 24a provided downstream from the branch point of the drain pipe 24 with the flow path, a second valve provided in the flow path, and the flow And a flushing pump provided in the passage. These are hereinafter referred to as flushing systems.

  The pump installation floor of the pump station is often unmanned, and it is preferable to use an electric type so that the valve can be opened and closed by operating or controlling it from the pump operation room or remotely, and the function of the electric valve is lost due to water on the pump installation floor. In order to prevent this, it is preferable to select a waterproof type when installing a valve or a flushing pump below the water level where flooding is assumed. The second valve is preferably a gate valve, a ball valve, a funnel valve, or the like having a large valve opening cross section when the valve is opened, because pumped water containing foreign matter etc. always passes through the pump.

  When the drainage pipe 24 is clogged with foreign matter or the like, the first valve is closed, the second valve is opened, water is sent to the drainage pipe 24 side through the flow path by the flushing pump, and water is discharged from the drainage pipe 24 to the drainage means 22. To reverse flow. With this water flow, foreign matter and the like can be returned to the chamber, and further returned to the sub-flow channel pipe portion 31 through the drainage means 22.

  The flushing pump is a pressure sufficiently higher than the pumping pressure of the sub-flow pipe section 31 in consideration of the pipe loss up to the sub-flow pipe section 31 so that the vertical pump can be made to flow backward even when it is in operation. It is preferable to select a pump capable of discharging gas. It is preferable that the inner diameter of the drainage pipe 24 is larger than the particle size that can pass through the drainage means 22 so that foreign matter or the like that has passed through the drainage means 22 is not clogged in the drainage pipe 24. In many pump stations, there is a dust removal facility before water flows into the suction tank, and large foreign objects are removed by the dust remover. Therefore, the particle size of foreign matters contained in the water pumped up by the pump can be based on the screen width of the dust remover.

  FIG. 5 is a view of the vicinity of the chamber portion which is a modified example of FIGS. 1 and 2, and shows a cross section near the chamber portion 6. The bend pipe section 4 that extends upward from the suction pipe 12 side and forms a main flow path toward the side discharge flange 15 has a first flange 17 at the upper end opening of the suction pipe 12 opening. The main shaft 8 or the output shaft 21 that passes through the suction pipe 12 in the direction of the first flange 17 may be provided, and the second impeller 32 may be attached to the main shaft 8 or the output shaft 21. The second impeller 32 generates a water flow from the lower side of the first flange 17 toward the first flange 17. By this water flow, water is efficiently discharged from the drainage means 22 formed on the first flange 17 and the second flange 20. Cooling efficiency is improved.

  The second impeller 32 not only generates a water flow in the direction of the first flange 17 but also has a blade forming portion 33 having a foreign matter crushing function (a rotation side of the foreign matter crushing function) in a part of the second impeller 32. Alternatively, the foreign matter may be cut between the second impeller 32 and the opposing fixed side 34 (of the foreign matter crushing function).

  Further, if the opening diameter just below the heat exchanger 19 is reduced to a small size, air or light dust that tends to collect at the rotating shaft center near the center of the heat exchanger 19 is guided to the drainage means 22 by the water flow, and is passed through the chamber section 6 and the drain pipe 24. Can be discharged to the outside.

  FIG. 6 is a view of the vicinity of a chamber portion which is a modification of FIG. The outer diameter of the first flange 17 is larger than the outer diameter of the second flange 20, and the chamber cover 23 includes a ceiling surface 35 positioned above the motor housing 18, the ceiling surface 35, and the first A second surface 36 extending from the upper surface of the flange 17 may be provided. The ceiling surface 35 may be provided with an inspection window 35a that can be opened and closed.

  6A is a view of the vicinity of a chamber portion that is a modification of FIG. A drain pipe 24 communicating with the chamber portion 6 may be provided on the ceiling surface 35. The drain pipe 24 can also serve as an air vent pipe. In this case, the drain pipe 24 is provided with at least two bent portions. In such a case, it is preferable to have a curvature and a space inner diameter as large as possible so that no foreign matter is caught at the bent portion. Specifically, the drain pipe 24 has a bent portion of the drain pipe 24 of the drain means 22. It is preferable to have a curvature larger than the narrowest gap length or a space larger than the minimum inscribed sphere diameter of the space.

  FIG. 6B is a view of the vicinity of the chamber portion which is a modification of FIG. Moreover, FIG. 6C is AA sectional drawing of FIG. 6B. As shown in these drawings, a cooling fin 18 a extending outward from the outer peripheral portion of the motor housing 18 can be attached to improve the cooling effect.

  FIG. 7 is a view of the vicinity of a chamber portion which is another modification of FIG. The outer diameter of the first flange 17 is larger than the outer diameter of the second flange 20, and the chamber cover 23 includes a first surface 36 extending in an outer diameter direction from a side surface of the second flange 20 of the motor housing 18, A first surface 36 and a second surface 37 extending from the upper surface of the first flange 17 may be provided.

  FIG. 8 is a view of the vicinity of a chamber portion which is another modification of FIG. The outer diameter of the second flange 20 is larger than the outer diameter of the first flange 17, and the chamber cover 23 includes a first surface 36 ′ extending from the side surface of the first flange 17 in the outer diameter direction, and the first surface. A surface 36 ′ and a second surface 37 ′ extending from the lower surface of the second flange 20 may be provided.

  FIG. 9 is a view of the vicinity of a chamber portion which is another modification of FIG. The outer diameter of the second flange 20 is larger than the outer diameter of the first flange 17, and the chamber cover 23 includes a first surface 36 '' extending from the lower surface of the first flange in the outer diameter direction, and the first surface. And a second surface 37 ″ extending from the lower surface of the second flange 20.

  Needless to say, it is desirable that the pump equipment such as the driving device and the discharge valve is waterproof so that it can be used even when it is submerged. It can be used as a drainage system that can be operated remotely by supplying drive power and control signals from the outside.

  When the water level of the suction water tank is up to the top of the impeller 9, the motor is started and the output shaft 21 of the motor starts to rotate. Since the output shaft 21 is fixed to the main shaft 8 (shaft) via a joint, the rotation of the output shaft 21 is transmitted to the impeller 9 positioned at the lower end fixed to the main shaft 8, and the rotation of the impeller 9 is accompanied by the rotation of the impeller 9. The water in the suction water tank is pumped up, drained from the discharge port 2 of the bend pipe part 4 through the suction pipe part 3.

  During this operation, the air that was in the main flow path before starting is discharged by pumping water in the main flow path, and is discharged from the discharge port 2 after the main flow path is filled with pumped water. On the other hand, when the upper part of the subchannel pipe part 31 has a watertight structure, since the subchannel is above the main channel, the air at the time of start-up remains difficult to be discharged.

  On the other hand, in the present invention, since the upper part of the sub-flow pipe part 31 does not have a watertight structure, when the pumping is started and the pressure of the suction pipe part 3 and the bend pipe part 4 increases, Air escapes from the top of 31. Furthermore, after the air has escaped, it is filled with pumped water, and the pumped water touches the heat exchanger 19 to take away the heat generated by the rotating motor, so that efficient heat exchange can be performed.

  FIG. 10A is a view of the vicinity of a chamber portion which is still another modification of FIG. The chamber portion includes a single or plural groove portions 21a that are drainage means 22 sandwiched between the first flange 17 of the bend pipe portion 4 and the second flange 20 of the motor portion 5, or the single or plural convex portions. (Spacer) 41 (shown). When the drainage means is constituted by the convex portion 41, the lower surface of the convex portion 41 is supported by the first flange 17, and the upper surface of the convex portion 41 supports the second flange 20. This creates a gap between the upper surface of the first flange 17 and the lower surface of the second flange 20.

There is no restriction | limiting in particular in the arrangement position and shape of the convex part 41. FIG. For example, as shown in FIG. 10B, a plurality of convex portions 41 are provided on the first flange 17, and a hole 42 through which a bolt for fastening the first flange 17 and the second flange 20 passes is formed in a part thereof. It may be.

  Moreover, as shown in FIGS. 10C to 10F, the shape of the convex portion 41 may be a hexagonal column, a rectangular parallelepiped (cube), a cylinder, or a part thereof may be a curved surface. Furthermore, as shown to FIG. 10G, the convex part 41 may arrange | position the some piece 41a of a hollow cylinder axial direction division body shape in the annular | circular shape so that a clearance gap may be opened mutually.

Furthermore, by changing to the convex portions 41 having different heights, not only the gap can be adjusted, but also the axial positions of the motor unit 5, the main shaft 8, and the impeller 9 can be adjusted with respect to the first flange 17. I can do it. Further, the impeller 9 fixed to the lower portion of the main shaft 8 has an outer diameter larger on the axial motor portion 5 side than on the non-motor portion 5 side, and the inner wall of the suction pipe portion 3 near the impeller 9 also has an outer diameter of the impeller 9. The shape is adapted to the change. Therefore, the clearance between the impeller 9 and the suction pipe inner wall can be adjusted by changing to the convex portion 41 having a different height. Since the clearance between the rotating impeller 9 and the fixed suction pipe portion 3 greatly affects the pump performance, the pump performance can be improved by replacing the convex portion 41 with a different height.

  Further, by forming the gap between the upper surface of the first flange 17 and the lower surface of the second flange 20 so that the axial center side is wide and the outer diameter side is narrow, even when the convex portion 41 having the same shape is used, the convex portion The clearance can also be adjusted by adjusting the position of 41 in the radial direction, and similarly, the clearance between the outer diameter side of the impeller 9 and the inner wall side of the suction pipe portion 3 can be adjusted.

  The convex portion 41a in FIG. 10G has a three-dimensional shape obtained by cutting a cylinder along two planes passing through the axis. The convex portions 41a having this shape are arranged with a gap therebetween to form a gap. By collecting and arranging the convex portions 41a on the inner diameter side, the gap in the planar direction formed between the convex portions 41 can be changed. Also, without limiting to this convex shape, the gap can be changed depending on the arrangement of various convex shapes, the drainage resistance of the drainage means can be changed by changing the gap, and the amount of drainage Can be controlled.

  The gap between the upper surface of the first flange 17 and the lower surface of the second flange 20 is a shape in which the axial center side is widened and the outer diameter side is narrowed. Even when the convex portion 41 having the same shape is used, the amount of drainage is similarly controlled. it can.

  Returning to FIG. 10A, in the case of such a chamber portion, the diameter of the first flange 17 and the diameter of the second flange 20 may be substantially equal. The chamber cover 23 in the chamber portion includes a lower chamber cover 51 and an upper chamber cover 52.

  The lower chamber cover 51 covers the first flange 17 from the circumferential direction, and includes a cylindrical portion 51a that contacts the outer peripheral surface of the first flange 17 and a bottom portion 51b that extends inward from the lower portion of the cylindrical portion 51a. Further, a seal member 53 such as an O-ring is disposed between the first flange 17 and the chamber cover 23, more specifically, between the upper surface of the bottom portion 51 b and the lower surface of the first flange 17.

  The upper chamber cover 52 covers the second flange 20 from the circumferential direction, and includes a cylindrical portion 52a that contacts the outer peripheral surface of the second flange 20 and a ceiling portion 52b that extends inward from the upper portion of the cylindrical portion 52a. Further, a seal member 54 such as an O-ring is disposed between the second flange 20 and the chamber cover 23, more specifically, between the lower surface of the ceiling portion 52 b and the upper surface of the second flange 20.

  The upper chamber cover 52 and the lower chamber cover 51 are fastened by bolts 55 penetrating from the upper chamber cover 52 to the lower chamber cover 51, and the seal member 53 is in close contact with the first flange 17 and the lower chamber cover 51 and is sealed. The member 54 is in close contact with the second flange 20 and the upper chamber cover 52. As a result, the water introduced into the chamber portion reaches the seal members 53 and 54, but does not leak from between the first flange 17 and the lower chamber cover 51 or between the second flange 20 and the upper chamber cover 52. The water is drained from the drain pipe 24.

  In FIG. 10A, the chamber cover 23 is constituted by the lower chamber cover 51 and the upper chamber cover 52 that are divided into two in the direction orthogonal to the output shaft 21. It may be divided not only into three parts but also into three or more, may be divided in the direction of the output shaft 21, or may be divided into three or more in the direction of the output shaft 21.

  Further, the upper chamber covers 52c and 52d (FIG. 10H) and the lower chamber covers 51c and 51d, which are respectively divided into two on the plane passing through the shaft, are coupled via the seal member 57 with the shaft interposed therebetween, and further the upper chamber cover in the axial direction. The cover combined body 52 ′ (FIG. 10I) and the lower chamber-cover combined body 51 ′ may be configured by fastening the bolts 55 with the spacers 58 between them and changing the gaps (FIG. 10J).

  Further, as shown in a top view in FIG. 11, the chamber cover 23 is a substantially cylindrical elastic membrane, and sandwiches the first flange 17 and the second flange 20 from the side surface, and the elastic membrane and the first flange 17 and A space formed by the second flange 20 may be a chamber.

  Further, as shown in FIG. 12, a clamp 56 having a shape in which the lower chamber cover 51 and the upper chamber cover 52 shown in FIG. 10A are integrated may be used as the chamber cover 23.

  In addition, as shown in FIG. 13, in the embodiment shown in FIG. 10A, the lower surface of the outer periphery of the first flange 17 is inclined so as to increase toward the outer periphery, and the upper surface of the bottom 51 b in the lower chamber cover 51 is inclined so as to decrease toward the inner side. May be. Thereby, the seal member 53 is more closely attached to the first flange 17 and the lower chamber cover 51.

  Similarly, the upper surface of the outer peripheral portion of the second flange 20 may be inclined so as to be lower toward the outer periphery, and the lower surface of the ceiling portion 52b in the upper chamber cover 52 may be inclined so as to be higher toward the inner side. Further, in the embodiment shown in FIG. 12, the predetermined surfaces of the first flange 17, the second flange 20, and the chamber cover 23 may be similarly inclined.

  Although a plurality of embodiments have been described above, any two or more embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Suction port 2 Discharge port 3 Suction pipe part 4 Bend pipe part 5 Motor part 6 Chamber part 7 Bell part 8 Main shaft 9 Impeller 10 Bearing part 11 Guide vane 12 Suction pipe 13 Connection pipe part 14 Discharge pipe 15 Discharge flange 16 Discharge cover 17 First flange 17a Hole 17b Hole 18 Motor housing 18a Cooling fin 19 Heat exchanger 19a Groove 20 Second flange 21 Output shaft 22 Drain means 22a Groove 23 Chamber cover 23a Through hole 24 Drain pipe 24a Valve (first valve )
24 b Flow meter 24 c Drain thermometer 24 d Pumped water thermometer 25 Chamber cover fixing bolt 26 First surface 27 Second surface 28 Inspection window 29 Air pipe 30 Valve 31 Sub-flow pipe section 32 Second impeller 33 Blade formation part ( Rotating side of foreign object crushing function)
34 Fixed side 35 of the foreign matter crushing function Ceiling surface 36 First surface 37 Second surface 38 Joint 41 Projection 41a Piece 42 Hole 51 Lower chamber cover 51a Cylindrical portion 51b Bottom portion 52 Upper chamber cover 52a Cylindrical portion 52b Ceiling portions 52c, 52d Upper Chamber cover 52 'Upper chamber cover assembly 53 Seal member 54 Seal member 55 Bolt 56 Clamp 57 Seal member 58 Spacer

Claims (6)

A vertical shaft pump for guiding water from a suction port opened downward to a discharge port facing the side of the upper part of the pump, wherein the suction pipe part, a bend pipe part connected to the upper part of the suction pipe part, and the bend pipe It is composed of a motor part located in the upper part of the part, and a chamber part,
The suction pipe portion includes a suction pipe, a main shaft extending in a substantially vertical direction in the suction pipe, an impeller fixed to the main shaft, and a bearing portion that supports the main shaft,
The bend pipe part includes a connection pipe part connected to the suction pipe, a discharge pipe directed to the side of the connection pipe part, a discharge flange, and a first flange located above the suction port. And having
The motor unit includes a motor housing, a second flange provided at a lower portion of the motor housing, a heat exchanger provided at the lower portion of the motor housing, and an output coupled to the main shaft through the heat exchanger. An axis, and
The chamber section includes a first flange of the bend pipe section, a second flange of the motor section, a spacer provided between the first flange and the second flange, a chamber cover, and an interior of the chamber section. A drain pipe having an opening in the
A pump characterized in that water pumped up from a suction water tank is guided between the first flange and the second flange from the first flange side and discharged to the outside through the drain pipe.   The pump according to claim 1, wherein the chamber cover is composed of a plurality of members divided in a direction orthogonal to the output shaft. The chamber cover is
A lower chamber cover covering the first flange from the circumferential direction;
An upper chamber cover for covering the second flange from the circumferential direction;
The pump according to claim 1 or 2, comprising: The chamber cover is
A cylindrical portion in contact with the outer peripheral surfaces of the first flange and the second flange;
A ceiling portion extending inward from the upper portion of the cylindrical portion;
A bottom portion extending inward from a lower portion of the cylindrical portion;
Have
The lower surface of the outer periphery of the first flange is inclined so as to be higher toward the outer periphery,
The upper surface of the outer periphery of the second flange is inclined so as to become lower toward the outer periphery,
The upper surface of the bottom portion is inclined so as to become lower toward the inner side,
The pump according to any one of claims 1 to 3, wherein a lower surface of the ceiling portion is inclined so as to become lower toward an inner side.   The pump according to claim 1, wherein a seal member is provided between the first flange and the chamber cover and / or between the second flange and the chamber cover.   The concave portion and / or convex portion of the pumping contact portion of the heat exchanger has a polygonal pyramid, cone or spherical surface in which the apex is located in the vicinity of the main shaft, the vicinity of the main shaft is on the pump side, and the outer peripheral side where the drainage means is located is on the motor side. 6. The pump according to claim 1, wherein the pump has a stepped shape.