JPH05272485A - Motor-driven combination pump device - Google Patents

Abstract

PURPOSE:To combine two independent pumps in the state of being direct-coupled to one motor, dispose the motor above the liquid surface of liquid to be dealt with, and submerge the pumps under the liquid surface. CONSTITUTION:In a pump leg 6 on the driving side of a motor 1, a bracket 1a, a flange 7, discharge joints 3a, 3b, extended pipes 4a, 4b and a scroll chamber cover 41a are formed integrally, and the extended pipes 4a, 4b are disposed at approximately 180 deg. on the circumference. In a space suction casing 45 fitted to the lower face of the pump leg 6, the scroll chamber 10a of a pump 40a and the scroll chamber 10b of a pump 40b are integrally formed with suction ports 46a, 46b facing each other, and the lower face of the casing 45 is provided with a scroll chamber cover 41b. The scroll chamber 10a is directly communicated with the extended pipe 4a, and the scroll chamber 10b is communicated with the extended pipe 4b through a junction discharge port 17 formed integrally in the axial direction at the side of the scroll chamber 10a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is constructed by combining two independent pumps into a single electric motor and directly connecting them. The electric motor is disposed above the liquid level of the liquid to be handled, and the pump is placed below the liquid level. The present invention relates to an immersion type electric compound pump device. The present invention relates to an electric compound pump device suitable for a coolant pump that handles a cutting fluid of a machine tool, including a centrifugal pump and a mixed flow pump having a spiral chamber.

[0002]

2. Description of the Related Art For example, as a pump used in the field of machine tools, the Japan Electrical Manufacturers' Association standard JEM1242.
(1970) A single-stage centrifugal pump described in "Coolant Pump" (Conventional Document 1) is known, and a multi-stage immersion pump is disclosed in Japanese Patent Laid-Open No. 189399/1987 (Patent Document 2). Things are known. Further, as a general composite pump, those shown in JP-A-63-32195 (conventional document 3) and Japanese Utility Model Laid-Open No. 1-97032 (conventional document 4) are known. As a coolant pump for machine tools, pressure type electric pumps are used for lubrication / cooling of cutting / grinding surfaces and cutting / blowing of grinding powder, and flow rate type electric pumps for cutting / washing of grinding powder. For example, two or more electric coolant pumps are usually used for one machine tool.

[0003]

According to the above-mentioned conventional technique, a space for installing two or more electric pumps is required for one machine tool, and two or more wiring systems to the electric motors are required. There are problems such as the above. This has the same problem when two identical electric pumps are used when the pressure and the flow rate are the same. Even if the required pump characteristics are the same, it is possible to use two discharge pipes for one pump with double the flow rate, but if one pipe is closed or throttled, the flow rate of the other pipe will change without fail. To avoid this, use two identical electric pumps.

An object of the present invention is to construct a structure in which two independent pumps are combined and directly connected to one electric motor, the electric motor is arranged on the liquid surface of the liquid to be handled, and the pump is immersed below the liquid surface. Type electric compound pump device.

[0005]

The electric compound pump device according to the first aspect of the present invention refers to all the embodiments, and two pumps (40
a and 40b, 50a and 50b, 8a and 8b, 8a and 28
b, 38a and 38b) for mounting the electric compound pump device, and a drive shaft (14, 26) fixed on the flange and penetrating therebelow.
And 14a) and an impeller (43) of two groups (including one in which at least one pump is a multistage pump) mounted vertically below the drive shaft.
a and 43b, 53a and 53b, 9a and 9b, 9a and 29
b and 36a and 36b), and the individual swirl chambers (10a, 10b and 34) surrounding the respective impellers of the pumps.
a and 34b) forming a swirl chamber cover (41a, 5a)
Etc.) and casings (45, 12, 21, 23, 33a)
And 33b) and two substantially vertical extension tubes (4a, 4b and 37) which secure the swirl chamber cover and casing below the flange (7) and are arranged around the drive shaft. , The extension pipe communicates with the two discharge joints (3a and 3b) provided on the flange and the respective volute chambers, and suction ports (46a, 46b, 16a, 16b, 24, 31a) provided on the volute chambers. 31b) is an opening below the liquid level (19) of the liquid to be handled.

Invention 2 is the same as Invention 1, except that Embodiments 1, 2 and
With reference to 3 and 4, the horizontal volute chamber cover at the uppermost part of the casing, the flange (7), the respective discharge joints and the respective extension pipes are integrated to form a pump leg. A third aspect of the present invention is the same as the first or second aspect, with reference to the first embodiment. The casing (45) includes suction ports (46a, 46b) of the pumps (40a, 40b) and swirl chambers (10a, 10b) of the pumps. ) And relay outlet (17)
And a swirl chamber cover (41a, 41b) for closing the upper and lower sides of the interval suction casing, respectively, and the both suction ports face each other through the suction space (47). In addition, the relay discharge port is arranged laterally of the one spiral chamber (10a) in the axial direction and communicates with the other spiral chamber (10b).

At this time, the invention 4 is such that, in the invention 1, 2 or 3, the pump (40b) having a larger outer diameter of the impeller is located below. A fifth aspect of the invention is the single-stage pump (50a) of the first or second aspect of the invention, with reference to the second embodiment, wherein the two pumps are located above and a suction port is directed upward.
Multi-stage pump (50
b), both pumps are provided with a common casing (12), through which a swirl chamber (10a) of the single-stage pump and a final stage of the multi-stage pump are provided via a partition wall (11). The spiral chamber (10b) and the relay discharge port (17) are integrally formed, and the relay discharge port is disposed laterally of the spiral chamber of the single-stage pump in the axial direction to form the final stage of the multi-stage pump. It leads to the whirlpool chamber.

[0008]

In the first aspect of the invention, since there is one electric motor for the two pumps, it is advantageous in terms of the wiring system of the electric motor, independence of the pump operating state, and reduction of the projected area in the axial direction. Then, the pump device is simply installed and fixed to a tank or the like in which a handling liquid is stored with a flange for installation, and the electric motor is submerged above the liquid level and the two pumps are submerged below the liquid level, so that no suction pipe is required. Also, the liquid supply pipes that are connected to the discharge joints for each pump just above the flange will crawl just above the tank and will not get in the way,
Easy installation and piping work and good finish.

In order to arrange the two extension tubes around the drive shaft, they can be arranged at a position of about 180 degrees without being approached on the circumference, and at this time, the fluid is vaned by the vortex shape of the spiral chamber. The radial loads acting on the vehicle are offset by the two pumps to reduce the radial loads on the bearings and there is no risk of the elongated drive shaft bending and the impeller contacting the casing.

In the invention 2, since the pump leg is integrated with the flange having the discharge joint and the swirl chamber cover by the two extension pipes arranged around the drive shaft, the pump leg has a high rigidity and a simple structure, and the number of parts is large. To reduce. Further, since the rigidity between the lower two pumps and the electric motor 1 is high, the relative dimensional accuracy between the rotating impeller and the spiral chamber is high. By arranging the two extension tubes at a position of about 180 degrees on the circumference around the drive shaft, not only the rigidity of the pump leg is further high, but also the castability is particularly good.

According to the third aspect of the invention, since the two spiral chambers are integrally formed in one interval suction casing, the number of parts is small. Since the suction ports face each other and the impellers face each other,
The thrust load of the impeller is offset and the thrust load of the bearing is reduced. The relay discharge port for the lower pump is also easily integrated, no special piping is required, and the outer diameter can be reduced. The interval suction casing is formed by simple machining on two parallel surfaces and can be easily assembled with the pump leg and the scroll chamber cover, ensuring the axial dimensional accuracy of the upper surface of both impellers and the members facing it. Easy to maintain and keep the axial gap to a minimum to minimize liquid leakage and improve pump characteristics. Since the drive shaft does not penetrate the swirl chamber cover of the lower pump, there is no leakage of the discharged liquid due to the penetration.

In the invention 4, since the pump having the larger outer diameter of the impeller is located at the lower side and the relay discharge port thereof passes the side of the spiral chamber of the smaller pump, the outer diameter of this portion which tends to be the largest. To make the pump part thinner and not to make the flange larger. The fact that the discharge liquid does not leak due to the drive shaft not penetrating the swirl chamber cover of the lower pump is particularly effective when the impeller outer diameter of the pump is larger and the discharge pressure is high.

According to the fifth aspect of the invention, the two spiral chambers and the relay discharge port having the partition wall as a boundary are integrally formed by casting or die casting in one casing, so that the number of parts is small and the outer diameter can be reduced. Since the suction port faces the opposite side in the axial direction and the impeller is back-to-back, the thrust load of the impeller is offset and the thrust load of the bearing is reduced. Leakage of the discharged liquid from the gap where the drive shaft penetrates the partition wall of the multi-stage pump is reduced by the discharge pressure of the single-stage pump, and the remaining leakage of the discharged liquid is collected on the discharge side of the single-stage pump, resulting in leakage loss. Not at all.

[0014]

EXAMPLE FIG. 1 is a longitudinal sectional view of Example 1, and FIG. 2 is a C of FIG.
-C sectional view, FIG. 3 is a DD sectional view of FIG. 1, FIG. 4 is a diffusion exploded view of an upper portion of FIG. 1, FIG. 5 is a diffusion exploded view of a lower portion subsequent to FIG. 4, and FIG. 7 is a vertical sectional view of the third embodiment, FIG. 8 is a vertical sectional view of the fourth embodiment, FIG. 9 is a sectional view taken along the line AA of FIG. 8, and FIG. 5 is a vertical sectional view of FIG. In the drawings, components having the same reference numerals have approximately the same function, and duplicate explanation may be omitted.

1 to 5, the discharge joints 3a and 3b and the extension pipe 4 are provided on the drive side below the vertical shaft electric motor 1.
A pump leg 6 in which a, 4b, and the swirl chamber cover 41a of the first pump 40a on the electric motor side are integrally formed is provided. Two discharge fittings 3a, 3b and extension tubes 4a, 4 of the pump leg 6
b are arranged at positions of approximately 180 degrees with respect to each other on the circumference. The pump leg 6 is further integrated with a flange 7 for mounting the combined pump device on a tank storing a liquid to be handled, and a bracket 1a on the drive side of the electric motor 1.

The swirl chamber cover 41a of the pump leg 6
On the lower surface of the gap suction casing 45 a plurality of bolts 13
It is attached with a. In this interval suction casing 45 whose rigidity is increased by the pillar 45a, the first and second spiral chambers 10a and 10b, which house the impeller 43a of the first pump 40a and the impeller 43b of the second pump 40b, are common. The suction ports 46a and 46b are formed to face each other through the suction space 47. The suction ports 46a and 46b open below the surface 19 of the liquid to be handled.

On the lower surface of the gap suction casing 45,
Further, there is a swirl chamber cover 41b of the second pump 40b, which is fixed by a plurality of bolts 13. The first impeller 43a and the second impeller 43b are the bearings 1 of the electric motor 1.
It is directly connected by a bolt 15 to a drive shaft 14 supported by b or the like. The first spiral chamber 10a directly fluidly communicates with the extension pipe 4a, but the second spiral chamber 10b is integrally formed laterally of the first spiral chamber 10a in the axial direction. It communicates with the extension pipe 4b through the discharge port 17. In this way, the swirl chamber cover 5a, which is a part of the pump leg 6, is provided with the first discharge port 18a and the second discharge port 18b. The impeller 43a of the first pump 40a arranged on the electric motor side is a closed-type impeller with a side plate 49 provided with a mouth ring 48, and the pump 40 is driven by the mouth ring 48.
It is preferable to suppress internal leakage of a.

According to the first embodiment, the two pumps are
One vertical shaft is coupled to the drive side below the electric motor to form an independent pump. Therefore, two independent pumps are operated even though the wiring system of the electric motor (wiring, necessary electromagnetic contactor, etc.) is one system. In addition, the operating state of the other pump does not change even if the valve or the like of one pump piping system is closed or throttled. The electric motor is an induction motor,
Even if the rotational speed (slip) of the electric motor changes to some extent by operating one valve, the operating state of the other pump does not substantially change. Although it becomes slightly longer in the axial direction, the projected area in the axial direction is the projected area of the electric motor of the capacity that combines the power of the two pumps, and is much larger than the projected area of two electric motors of a single electric pump. Small. In summary, since there is only one electric motor for the two pumps, the electric motor wiring system,
It is advantageous in terms of independence of the pump operating state and reduction of the projected area in the axial direction.

Since the bracket 1a, the discharge joints 3a and 3b, the flange 7, the extension pipes 4a and 4b and the spiral chamber cover 41a are integrated, the structure is simple and the number of parts is small. Further, since the rigidity between the lower first pump 40a and the second pump 40b and the electric motor 1 is high, the relative dimensional accuracy between the rotating impeller and the spiral chamber is high. And two discharge fittings 3
Since a, 3b and extension pipes 4a, 4b are arranged at positions of approximately 180 degrees to each other, the radial load of the fluid acting on the impeller is canceled by the vortex shape of the spiral chamber, and the radial load of the bearing such as the bearing 1b is offset. Will be reduced. Moreover, not only the rigidity itself is high, but also the castability is particularly good. This is extension pipe 4
The surfaces including the axes of a and 4b are divided surfaces XX of the upper mold and the lower mold of the casting mother die, so that both ends of the core for the extension pipes 4a and 4b are divided into the divided surfaces XX. It can be supported by.

Then, one interval suction casing 45 has two
The two spiral chambers 10a and 10b are integrally formed by casting or die casting, and the number of parts is small. Suction port 46a, 46b
Are opposed to each other and the impellers 43a and 43b are opposed to each other, so that the thrust load of the impeller is offset and the thrust load of the bearing is reduced. The relay discharge port for the second pump 8b is also easily integrated, no special piping is required, and the outer diameter dimension can be reduced. Since the interval suction casing 45 can be easily assembled with the pump leg 6 and the spiral chamber cover 41b by simple machining of two parallel surfaces, both impellers 43a,
It is easy to ensure the dimensional accuracy in the axial direction between the upper surface of 43b and the member facing it, and it is possible to maintain the axial gap to a minimum to minimize the leakage of liquid and improve the pump characteristics. Second
Since the drive shaft 14 does not penetrate the swirl chamber cover 41b of the pump 40b, the leakage of the discharged liquid due to the penetration does not occur at all. This is particularly effective when the outer diameter of the impeller of the pump 40b is larger and the discharge pressure is higher.

A modification of the first embodiment will be described. Bracket 1
It may be advantageous to separate a and the pump leg 6 as well, the electric motor without the pump leg being formed as an intermediate assembly makes it easier to test the electric motor and a general-purpose electric motor can be used. The flange, the scroll chamber cover, and the extension pipe may be combined as separate members to improve castability, and a structure in which the relay discharge port is also separated from the casing 12 can be adopted. It is also possible to arrange an impeller with a higher flow rate below to prevent the suction of air due to vortices when the liquid level 19 drops. The swirl chamber is not limited to one having a gradually increasing radial cross section, and may have a simple circular outer periphery, and the pump may have multiple stages.

In the second embodiment shown in FIG. 6, a portion similar to that of the first embodiment is that the drive side below the vertical axis electric motor 1 is
Discharge joints 3a and 3b, extension pipes 4a and 4b, and a pump leg 6 integrally formed with a swirl chamber cover 5a of the first pump 50a are provided. The two discharge joints 3a, 3b and the extension tubes 4a, 4b of the pump leg 6 are arranged at a position of approximately 180 degrees with respect to each other. A bracket 1a on the drive side of the electric motor 1 and a flange 7 are further integrated with the pump leg 6. The swirl chamber cover 5a opens the suction port 16a.

A casing 12 is attached to the lower surface of the swirl chamber cover 5a of the pump leg 6. The casing 12 is formed so that the spiral chambers 10a and 10b accommodating the impeller 53a of the single-stage pump 50a and the impeller 53b of the final stage of the multi-stage pump 50b are back to back with the common partition wall 11 as a boundary, and the suction ports 16a and 16b. Both open below the liquid level 19 of the liquid to be handled, facing outward in the axial direction.

Below the casing 12, a casing 51, a guide blade 52, and an impeller 53b are arranged and attached to the pump leg 6 with a plurality of bolts 13 together with the spiral chamber cover 5b. The swirl chamber 10a of the single-stage pump 50a directly communicates with the extension pipe 4a, but the swirl chamber 10b of the multi-stage pump 50b has a relay discharge port 17 integrally formed laterally of the swirl chamber 10a in the axial direction. Through the extension pipe 4b.

According to the second embodiment, since there is only one electric motor for the two pumps, it is advantageous in terms of the wiring system of the electric motor, independence of the operating state of the pump, and reduction of the projected area in the axial direction. And the bracket 1a, the discharge joint 3a, 3
b, flange 7, extension tubes 4a, 4b, and swirl chamber cover 5
a is integrated, has a simple structure, and has a small number of parts. Further, since the rigidity between the lower single-stage pump 50a and the multi-stage pump 50b and the electric motor 1 is high, the relative dimensional accuracy between the rotating impeller and the spiral chamber is high. And two discharge joints 3a, 3b
Since the extension pipes 4a and 4b are arranged at positions of approximately 180 degrees with respect to each other, the radial load of the fluid acting on the impeller is canceled by the vortex shape of the spiral chamber, and the radial load of the bearing such as the bearing 1b is reduced. .. Moreover, not only the rigidity itself is high, but also the castability is particularly good. This is to support both ends of the core for the extension pipes 4a and 4b by dividing the surfaces including the axial centers of the extension pipes 4a and 4b into the dividing faces of the upper mold and the lower mold of the casting mother die. Because you can.

Then, in one casing 12, the partition wall 11
The two swirl chambers 10a and 10b are integrally formed by casting or die-casting at the boundary, and the number of parts is small. Suction port 1
6a and 16b face the opposite side in the axial direction, and impellers 53a and 5a
Since 3b are back-to-back, the thrust load of the impeller is offset and the thrust load of the bearing is reduced. The relay discharge port 17 for the multi-stage pump 50b is also easily integrated, no special piping is required, and the outer diameter size can be reduced. Leakage of the discharged liquid from the gap where the drive shaft 14 penetrates the partition wall 11 of the multi-stage pump 50b is reduced by the discharge pressure of the single-stage pump 50a, and leakage of the remaining discharged liquid is reduced by the single-stage pump 50a.
There is no leakage loss as it is collected on the discharge side. Suction port 16a of single-stage pump 50a and suction port 16 of multi-stage pump 50b
Since b does not share a suction space in the vicinity, it is convenient when it is required to attach a mesh filter suitable for each pump.

In the third embodiment shown in FIG. 7, a pump in which the discharge joints 3a and 3b, the extension pipes 4a and 4b, and the spiral chamber cover 5a of the first pump are integrally formed on the lower drive side of the vertical motor 1. Legs 6 are provided. A bracket 1a on the drive side of the electric motor 1 and a flange 7 are further integrated with the pump leg 6. A casing 12 is attached to the lower surface of the swirl chamber cover 5a of the pump leg 6.

In this casing 12, the first and second spiral chambers 10a and 10b for accommodating the impeller 9a of the first pump 8a and the impeller 9b of the second pump 8b are separated by the common partition wall 11 as a boundary. Formed facing back to back. The lower surface of the casing 12 further has a swirl chamber cover 5b of the second pump 8b, which is fixed to the swirl chamber cover 5a under the pump leg 6 together with the casing 12 by a plurality of bolts 13. And the first impeller 9
The a and the second impeller 9b are directly connected by a bolt 15 to a drive shaft 14 supported by a bearing 1b of the electric motor 1 and the like. The swirl chamber covers 5a and 5b have suction ports 16a and 16b, respectively.
Is provided to open below the level 19 of the handling liquid.

The first spiral chamber 10a directly communicates with the extension pipe 4a, while the second spiral chamber 10b is integrally formed laterally of the first spiral chamber 10a in the axial direction. It communicates with the extension pipe 4b through the discharge port 17. Thus, the swirl chamber cover 5a, which is a part of the pump leg 6, has a first
The second ejection port 18a and the second ejection port 18b are provided.

According to the third embodiment, one electric motor and two electric motors are used.
With respect to the single pump, it is advantageous in terms of the wiring system of the electric motor, the independence of the operating state of the pump, the reduction of the projected area in the axial direction, and the like. The bracket 1a, the discharge joints 3a and 3b, the flange 7, the extension pipes 4a and 4b, and the first spiral chamber cover 5a.
Is integrated and has a simple structure. Further, the rigidity between the lower first pump 8a and second pump 8b and the electric motor is high, and the relative dimensional accuracy between the rotating impeller and the spiral chamber is high.
The two swirl chambers are shaped without undercut from both sides and are not only integrally formed by casting or die casting in one casing 12, but also the relay discharge port for the second pump 8b is the first. The swirl chamber 10a of the pump is 10
Since it is smaller than b, it is easily integrated and does not require special piping. A gap for relative movement exists between the partition wall 11 and the second impeller 9b, and leakage loss occurs due to the difference in discharge pressure between the two pumps. Much less than leakage due to pressure itself. If both pumps have the same pressure, there will be no leakage. The casing 12 has a pump leg 6 formed by simple machining of two parallel surfaces.
Also, it can be well coupled with the swirl chamber cover 5b.

A modification of the third embodiment will be described. Bracket 1
It may be advantageous to separate a and the pump leg 6 as well, the electric motor without the pump leg being formed as an intermediate assembly makes it easier to test the electric motor and a general-purpose electric motor can be used. The flange and the swirl chamber cover may be joined by a plate-like joined body to improve the castability by using the extension pipe as a separate member, and the relay discharge port may be separated from the casing 12.
It is also possible to arrange the impeller 9a having a higher flow rate at the lower side to prevent the suction of air due to the vortex when the liquid level 19 drops. The swirl chamber is not limited to one having a gradually increasing radial cross section, and may have a simple circular outer periphery, and the pump may have multiple stages.

In the fourth embodiment shown in FIGS. 8 and 9, a pump leg 6 is attached to the electric motor 1, and the pump leg 6 is provided with the discharge joints 3a and 3b, the extension pipes 4a and 4b, and the swirl chamber cover 5.
After integrally forming a, the bracket 1a and the flange 7 are also integrally formed. The structure is similar to that of the third embodiment. A first casing 21, a spacing casing 22, and a second casing 23 are sequentially mounted in parallel on the lower surface of the swirl chamber cover 5a of the pump leg 6 and fixed by bolts 13. The first casing 21 has a swirl chamber 10 for the first pump 8a.
A is formed to accommodate the impeller 9a, and a relay discharge port 17 is integrally formed laterally as in the third embodiment. The spacing casing 22 has a suction port 2 for the second pump 28b.
4 and the second discharge port 25 for the second pump are formed, and the column 22a that maintains the interval rigidity is integrally formed. The second casing 23 itself does not have a suction port, and the spiral chamber 1
0b is formed. The whirlpool chamber 10b sequentially includes a communication discharge port 25, a relay discharge port 17, an extension pipe 4b, and a discharge joint 3b.
Lead to In the fourth embodiment, the drive shaft 26 is separated from the rotary shaft of the electric motor 1 and is directly connected to the joint 27.

As a characteristic action of the fourth embodiment, since the drive shaft does not penetrate the pressure side (swirl chamber side) of the pump 28b having a higher discharge pressure, there is no leakage caused by such a situation. However, there is also a mode in which a pump with a smaller flow rate is arranged above to prevent air suction due to vortices from the liquid surface. In addition to the advantages such as the wiring system of the electric motor, the independence of the pump operating state, the reduction of the projected area in the axial direction and the advantage of integrating the pump legs, the relay discharge port 17 and the connection discharge port 25 allow
Advantageously, the discharge lines of the two pumps are formed automatically by stacking the casings.

In the fifth embodiment shown in FIG. 10, the electric motor 1
A pump leg 39 is attached to the pump leg 39. The pump leg 39 integrally forms the discharge joints 3a and 3b and the extension pipe 4a, and also integrally forms the bracket 1a and the flange 7. Discharge joint 3
A gas pipe or the like is screwed into the b without integrating the extension pipe 37. At the lower end of the pump leg 39, as the first pump, the multi-stage pump 3 including the impeller 36a and the canning 33a is provided.
8a is attached. The canning 33a includes an annular swirl chamber 34a and guide vanes 35, the first-stage suction port 31a faces downward, and the final-stage swirl chamber communicates with the discharge port 30a at the lower end of the extension pipe 4a of the pump leg 39.

Casing 3 having first stage suction port 31a
At the lower end of 3a, a spacing casing 32 including a column 32p, a part of the casing of the second pump 38b and the discharge port 30b is attached, and further at the lower end of the spacing casing 32, a suction port 31b is provided below. The casing 33b of the second pump 38b, which houses the impeller 36b and has the spiral chamber 34b, is attached. The discharge port 30b is connected to the extension pipe 37, and the first pump 38a and the second pump 38b are fixed by a bolt 13.

As a modification of the fifth embodiment, the suction port of the first pump may be directed to the electric motor side. Further, the extension pipe 37 such as a gas pipe is abolished, and the pump leg is provided with an extension pipe integral with the pump leg 39 extending from the discharge joint 3b to B in the figure to serve as a discharge port, and the volute chamber 34b of the single-stage pump 38b is provided. And a relay discharge port through the discharge port of the integral extension pipe may be integrally formed on a side portion of each casing 33a of the multi-stage pump 38a and the interval casing 32.

[0037]

According to the invention 1, since there is only one electric motor for the two pumps, it is advantageous in respect of the wiring system of the electric motor, independence of the operating state of the pump, and reduction of the projected area in the axial direction. There is. The pump device can be installed and fixed to the tank etc. with the installation flange, and the electric motor is on the liquid surface, and the two pumps are submerged under the liquid surface, so that there is no need for suction pipes. The liquid supply pipes connected to the discharge joints for the above pumps crawl just above the tank, and do not get in the way, so installation and piping work is easy and the finish is good. There is. By arranging the two extension tubes at a position of approximately 180 degrees on the circumference of the drive shaft, the radial load exerted by the fluid on the impeller is 2 due to the vortex shape of the spiral chamber.
The two pumps cancel each other out to reduce the radial load on the bearing, and the elongated drive shaft is bent so that the impeller does not come into contact with the casing.

According to the second aspect of the invention, since the pump leg is integrated by the two extension pipes, there is an effect that the rigidity is high, the structure is simple, and the number of parts is reduced, and the lower two pumps and the electric motor are provided. Since the rigidity between them is high, the relative dimensional accuracy of the rotating impeller and the spiral chamber is high, and if the two extension tubes are arranged at a position of approximately 180 degrees on the circumference around the drive shaft, the pump leg Not only is the rigidity high, but the castability is particularly good.

According to the third aspect of the invention, since the two spiral chambers and the relay discharge port are integrally formed in one interval suction casing, there are the advantages that the number of parts is small and the outer diameter can be reduced, and the impellers face each other. Therefore, the thrust load of the impeller is offset and the thrust load of the bearing is reduced. The gap suction casing is formed by simple machining of two parallel surfaces, and can be easily assembled with the pump leg and the scroll chamber cover, so that the axial gap on the upper surface of both impellers is kept to a minimum and liquid leakage is prevented. Is minimized and the pump characteristics can be improved. Further, since the drive shaft does not penetrate through the swirl chamber cover of the lower pump, there is an effect that the discharge liquid does not leak due to the penetration.

According to the fourth aspect of the invention, the pump having the larger outer diameter of the impeller is located at the lower side, and the relay discharge port thereof passes the side of the spiral chamber of the smaller pump. There is an effect that the outer diameter is reduced to make the entire pump portion thinner and the flange is not enlarged. The fact that the discharge liquid does not leak due to the drive shaft not penetrating the swirl chamber cover of the lower pump is particularly effective when the impeller outer diameter of the pump is larger and the discharge pressure is high.

According to the fifth aspect of the invention, the two swirl chambers and the relay discharge port are integrally formed in one casing, so that the number of parts is small and the outer diameter can be reduced. There is an effect that the loads are offset and the thrust load of the bearing is reduced. Then, the leakage of the discharged liquid from the gap where the drive shaft penetrates the partition wall of the multi-stage pump is reduced by the discharge pressure of the single-stage pump, and the remaining leakage of the discharged liquid is collected on the discharge side of the single-stage pump to cause a leakage loss. There is no effect.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment.

FIG. 2 is a sectional view taken along line CC of FIG.

FIG. 3 is a sectional view taken along line DD of FIG.

FIG. 4 is a diffusion exploded view of the upper part of FIG.

FIG. 5 is a bottom exploded view following FIG.

FIG. 6 is a vertical sectional view of the second embodiment.

FIG. 7 is a vertical sectional view of the third embodiment.

FIG. 8 is a vertical sectional view of the fourth embodiment.

9 is a sectional view taken along line AA of FIG.

FIG. 10 is a vertical sectional view of the fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor 1a Bracket 3a Discharge joint 3b Discharge joint 4a Extension pipe 4b Extension pipe 5a Swirl chamber cover 5b Swirl chamber cover 6 Pump leg 8a Pump 8b Pump 9a Impeller 9b Impeller 10a Swirl chamber 10b Swirl chamber casing 14 Partition wall 16a Suction port 16b Suction port 17 Relay discharge port 18a Discharge port 18b Discharge port 22 Interval casing 23 Casing 24 Suction port 25 Communication discharge port 30b Discharge port 31a Suction port 31b Suction port 32 Interval casing 33a Casing 34b Swirl chamber 34b Swirl chamber 34b 35 guide blade 36a impeller 36b impeller 37 extension tube 38a pump 38b pump 39 pump leg 40a pump 40b pump 41a swirl chamber cover 41b swirl chamber cover 43a impeller 43b impeller 45 Interval Suction casing 46a Suction port 46b Suction port 47 Suction space 48 Mouth ring 50a Pump 50b Pump 51 Casing 52 Guide vanes 53a Impeller 53b Impeller

Claims (5)

[Claims] 1. Two pumps (40a and 40b, 50a and 50b, 8a and 8b, 8a and 28b and 38a and 38).
a flange (7) for installation of the electric compound pump device comprising b), and an electric motor (1) having a drive shaft (14, 26 and 14a) fixed on the flange and penetrating below the flange; Two groups of impellers (43a and 43b, 53a and 53b, 9a and 9b, 9a and 29b and 36a and 36) are mounted vertically below the drive shaft.
b), a swirl chamber cover (41a, 5a, etc.) and a casing (45, 12, 21, 23) that surrounds each of these impellers and forms independent swirl chambers (10a and 10b and 34a and 34b) of each pump. , 33a and 33b) and two substantially vertical extension tubes (4a, 4b and 37) which secure the swirl chamber cover and casing below the flange (7) and are arranged around the drive shaft. The extension pipe communicates with the two discharge couplings (3a and 3b) provided on the flange and the respective volute chambers, and suction ports (46a, 46b, 16) provided on the volute chambers.
a, 16b, 24, 31a and 31b) are opened below the liquid level (19) of the liquid to be handled. 2. The electric composite pump device according to claim 1, wherein the horizontal uppermost swirl chamber cover of the casing, the flange (7), the respective discharge joints and the respective extension pipes are integrated into a pump. An electric compound pump device characterized by forming legs. 3. The electric composite pump device according to claim 1 or 2, wherein the casing (45) includes suction ports (46a, 46b) of the pumps (40a, 40b) and swirl chambers (10a, 40a) of the pumps (40a, 40b). 10b) and relay discharge port (17)
And a swirl chamber cover (41a, 41b) that closes the space suction casing from above and below, respectively, and both suction ports face each other through the suction space (47). In addition, the relay discharge port is disposed laterally of the one spiral chamber (10a) in the axial direction, and the other spiral chamber (10a) is arranged.
An electric compound pump device characterized by being connected to b). 4. The electric composite pump device according to claim 1, 2 or 3, wherein a pump (40b) having a larger outer diameter of said impeller is located below. 5. The electric composite pump device according to claim 1 or 2, wherein the both pumps are located at an upper position and have a single-stage pump (50a) whose suction port faces upward, and at a lower position, the suction port. And a multistage pump (50b) directed downwards, both pumps having a common casing (12), and a casing (10) for the single stage pump via a partition wall (11). , The final-stage swirl chamber (10b) of the multi-stage pump and the relay discharge port (17) are integrally formed,
The electric compound pump device, wherein the relay discharge port is disposed laterally of the spiral chamber of the single-stage pump in the axial direction and communicates with the final-stage spiral chamber of the multi-stage pump.