JPH0826867B2 - Eddy current type canned motor pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vortex flow that causes a gas generated in a suction pipe of a liquefied gas transfer vortex flow pump to automatically flow into and out of a low pressure portion of the pump during stoppage and operation. Mold pump.

[Prior Art] Conventional vortex flow pumps are also called Wesco pumps, and are suitable as, for example, pumps that transfer a small amount of liquid having a low viscosity to a high head.

That is, this type of pump, as shown in FIG.
A flow path 26 is formed in the outer peripheral portion of the impeller 30, and a suction port 16 and a discharge port 24 are provided at positions close to the flow path 26, and the pump handling liquid makes one round around the flow path 26 from the suction port 16. It is configured to rotate to obtain a high head and to pump it from the discharge port 24 to the outside.

More specifically, the pump unit 10 includes pump casings 14a and 14b that are divided into two parts, and one casing 14a includes a suction port 16 at the center. Also, the other casing
A circular pump channel 20 is provided in 14b.
The suction port 22 and the discharge port 24 are arranged adjacent to each other on the outer peripheral portion of the above, and the impeller storage chamber 18 of the first stage is formed at the joint with the other casing 14b. The suction port 22 communicates with the outer peripheral portion of the first-stage impeller storage chamber 18 via a flow path 26 formed in the casings 14a and 14b, and an opening portion with the first-stage impeller storage chamber 18. Groove the diffuser part 26a
Configure as. Pump casing configured in this way
At the center of 14a and 14b, the rotor shaft of the canned motor unit 12 is
The impeller 30 is axially mounted in the first-stage impeller storage chamber 18 and the vortex type pump impeller 32 is axially mounted in the circular pump passage 20. Reference numeral 23 indicates a blind plug for closing the external communication hole formed in the casing 14a to form the diffuser portion 26a.

However, in the pump flow path 20, a scroll constituted by sliding members on both side surfaces of the pump impeller 32.
34 and 36 are arranged so that one scroll 34 is fixed to the pump casing 14b and the other scroll 36 is fixed to a bearing housing 40 that supports a front bearing 38 provided at the end of the canned motor portion 12. Therefore, an annular pump chamber 42 is formed on the outer peripheral portion of the pump impeller 32 held by the pair of scrolls 34, 36. A flow passage 44 communicating with the front bearing 38 of the canned motor portion 12 is provided on the center side of the scrolls 34, 36, and this flow passage 44 is a joint surface between the scrolls 34, 36 and the pump impeller 32. It communicates with the pump chamber 42 through a gap formed in.

Therefore, the canned motor unit 12 is composed of the stator assembly 46 and the rotor assembly 48, the rotor shaft 28 is supported by the front bearing 38 and the rear bearing 50, respectively, and the front rotor chamber 52 is provided at both ends of the rotor assembly 48. And a rear rotor chamber 54 are formed. Further, one end of the stator assembly 46 is sealed by a flange-shaped end plate 56, a bearing housing 40 that supports the front bearing 38 is fixed to the front side surface of this end plate 56, and the pump casing 14a is attached to the flange portion. 14b are integrally coupled and fixed. On the other hand, the other end of the stator assembly 46 is also sealed by the end plate 58, and the bearing housing 60 supporting the rear bearing 50 is fixed to the end plate 58 to seal the rear rotor chamber 54. Note that the stator assembly 46
A terminal box 62 for connecting a power source is installed on the outer periphery of the bearing housing 60 that seals the rear rotor chamber 54.
A through hole 64 is bored to communicate with an external circulation tube 66.

In the vortex type canned motor pump having such a configuration, the rotor shaft 28 is rotated and the first-stage impeller 30 and the vortex type pump impeller 32 are rotated by the driving of the canned motor. As a result, the pump handling liquid is the first stage impeller.
Under the action of 30, it is sucked from the suction port 16 and flows into the flow path 26. At this time, the liquid is pressurized by the diffuser portion 26a and guided to the suction port 22 of the pump chamber 42 accommodating the pump impeller 32. Then, the liquid flowing into the pump chamber 42 is pressurized in the pump chamber 42 and discharged from the discharge port 24. In this way, a part of the pump handling liquid whose pressure is increased in the pump chamber 42 is guided to the pump flow passage 20 through the flow passage 44 through the gap formed between the pump impeller 32 and the scrolls 34, 36. He
It flows into the inner peripheral surface of the front bearing 38 and flows into the front bearing 38.
Lubricate. After that, a part of the pump handling liquid that has flowed into the front bearing 38 flows into the front rotor chamber 52 of the canned motor unit 12, passes through the gap between the stator and the rotor and the rear rotor chamber 54, and the inner circumference of the rear bearing 50. Is guided to the surface,
The rear bearing 50 is lubricated while cooling the motor portion.
In this way, a part of the pump handling liquid that has lubricated the rear bearing 50 is returned to the pump handling liquid supply tank through the circulation tube 66 from the through hole 64 formed in the bearing housing 64.

However, in the vortex type canned motor pump having the above-mentioned structure, the suction port 22 and the suction port 22 are formed in the gaps between the both side surfaces of the impeller 30 and the scrolls 34, 36 in contact with the impeller 30, and the flow path 26 formed in the outer peripheral portion of the impeller 30. This is because there is a gap between the backflow prevention partition wall provided between the discharge port 24 and the outer periphery of the impeller, and these gaps cause leakage loss, which greatly affects the pump characteristics.

For this reason, it is necessary to consider in manufacturing to make the gap of the impeller small, but if these gaps are made too small, the wear between them becomes severe and the pump characteristics are deteriorated. It is necessary to leave the gap to some extent.

Furthermore, this type of pump not only has a simple structure, but also has the characteristics of higher pump efficiency and a much higher head than a centrifugal pump in a region with a narrow flow rate range. Since the amount is small, the diameter of the discharge pipe can be made small and the driving power can also be reduced, so that its application is extremely wide.

[Problems to be Solved by the Invention] However, in the conventional vortex type pump, when the pump is stopped and started the next morning in summer, winter, or night when the difference in outside temperature is large, the liquid temperature in the pump suction pipe is in the suction tank. Liquefied gas in the suction pipe becomes gasified and flows into the pump casing via the pump suction part.

However, the impeller blades of the vortex flow pump have a large number of small cuts formed in the outer peripheral portion of the disk, and are completely separated in each adjacent chamber.

In addition, since the pump suction port is also provided on the outer peripheral part of the impeller, if the suction port is filled with gas when the pump rotates, all the chambers partitioned by the blades and blades are filled with gas, Pump startup is hindered.

Further, in the vortex type pump, it is common practice to make the gap between the impellers small and raise the pump head. Therefore, the vortex flow pump generates high noise peculiar to the pump.

In order to reduce this noise, it is possible to solve it by expanding the above gap, but the pump head is reduced.

Further, the vortex flow type pump cannot obtain sufficient suction performance only with the main impeller, and has the pump characteristics similar to those of the positive displacement pump.

Therefore, it is necessary to pay sufficient attention to the use of this type of pump, and especially when the power supply frequency (50 / 60Hz) is different, the same pump performance can be obtained unless all the specifications of the pump section are changed. There were many difficulties in handling, such as being unable to do so.

Therefore, an object of the present invention is to configure the centrifugal impeller as the pump section at the forefront stage and to configure the next stage as a pump section consisting of a vortex flow type pump impeller, which has pump characteristics of a small flow rate and high head, It is an object of the present invention to provide an eddy current type canned motor pump which can prevent cavitation in the pump section and reduce noise, and which has stable pump characteristics.

[Means for Solving the Problems] In order to achieve the above-mentioned object, a vortex type canned motor pump according to the present invention is a scroll (34, 36) that is made of a sliding material on both side surfaces of the vortex type pump impeller (32). And a canned motor part (12), in which a plurality of pump casings (14a, 14b) that form an annular pump chamber (42) are connected to the outer peripheral part of the swirl type pump impeller. In the eddy-current canned motor pump configured as above, a radial open impeller (30) consisting of radial straight blades is provided in the pump casing (14a) of the previous stage, and a vortex-type pump impeller (32) is provided in the pump casing (14b) of the next stage. Is provided, and the pump discharge port (26a) of the previous stage is communicated with the suction port (22) of the pump unit of the next stage through the passage (26) in the pump casing (14a, 14b). (14b) is opened to the suction side of the pump section, and is connected to the front rotor chamber (52) in the canned motor section (12) via the notch (41) of the bearing housing (40) of the front bearing (38). Discharge port that connects the pump discharge liquid of the next stage to the pump casing (14b) by forming a bypass hole (25) for communicating a part of the discharge liquid of the pump of the previous stage into the canned motor part (12). While discharging from the pump (24), a part of this pump handling liquid passes through the flow path (44) from the gap formed between the swirl type pump impeller (32) and the scrolls (34, 36), and the pump section ( It is configured to flow into the low pressure part of 10), and a part of the pump handling liquid introduced into the front rotor part (52) in the canned motor part (12) is partly transferred through the front bearing (38). It is configured so as to join the flow path (44), and further through the bypass hole (25). Then, the pump handling liquid introduced into the canned motor portion (12) is introduced into the front rotor chamber (54) through the gap between the stator assembly (46) and the rotor assembly (48) and the rear bearing (50) is introduced. It is characterized in that it is configured so as to communicate with the gas phase portion of the pump suction tank.

In this case, the flange-type end plate (56) provided at the connecting portion between the pump portion and the canned motor portion and the bearing housing (40) supporting the front bearing (38) have a predetermined thickness on the joint surface (70). The annular spacer may be attached to adjust the clearance between the vortex pump impeller (32) and the scrolls (34, 36).

[Operation] The vortex flow canned motor pump according to the present invention is configured such that the pressure of the pump unit of the previous stage pressurizes the rotor chamber of the canned motor unit and the low pressure unit of the pump unit of the next stage via the communication passage. It is possible to prevent the occurrence of cavitation in the gap between the impeller and the scroll of the next-stage pump portion and the enlarged portion of the low pressure portion at the gap outlet, and achieve noise reduction.

Also, by using a radial open impeller consisting of radial straight blades for the impeller in the pump casing of the previous stage, the pump head performance of this stage is constant even if the flow rate changes, therefore the flow rate of the vortex pump Vortex pump NPSHA (effective suction head)
Is always constant.

Furthermore, by providing a bypass hole communicating with the rotor chamber of the canned motor section in the pump casing of the next stage, the gas component generated in the pump chamber flows out to the gas phase section of the pump suction tank via the inside of the canned motor section. Therefore, even if the gas may partially flow into the low-pressure part of the pump part together with the liquid, if the impeller in the previous stage is a radial open impeller consisting of radial straight blades, Does not affect NPSHA (effective suction head).

In this way, it is possible to reduce the pump noise and easily design and manufacture a vortex pump having stable pump characteristics.

[Embodiment] Next, an embodiment of the vortex type canned motor pump according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of the vortex type canned motor pump according to the present invention, and FIG. 2 is an A- line in FIG.
A sectional view is shown. For convenience of explanation, the same components as those of the conventional vortex type canned motor pump shown in FIG. 4 are designated by the same reference numerals.

That is, in FIG. 1, reference numeral 10 is a pump portion,
Reference numeral 12 indicates a canned motor unit.

In this case, a multistage pump in which a plurality of pump casings are connected in series is conceivable as a pump for obtaining a high lift, but the present invention will be described with reference to a vortex flow type cander motor pump composed of two pump casings.

That is, the pump unit 10 includes pump casings 14a and 14b that are divided into two equal parts, and one casing 14a, which is the first stage (first stage), has a suction port 16 at the center.

A circular pump passage 20 is provided in the other casing 14b, which is the next stage (second stage), and the suction port 22 and the discharge port 24 are arranged adjacent to each other on the outer peripheral portion of the pump passage 20.

Then, a circular recess 15a is formed on the joint surface of one casing 14a.
And a circular convex portion 15b is formed on the joint surface of the other casing 14b, and these are connected to each other in a liquid-tight manner, and the end surface 15c of the circular convex portion 15b is connected to the first-stage pump chamber. An impeller storage chamber 18 is formed.

The suction port 22 is provided with a first-stage impeller storage chamber 18 via a flow path 26 as a communication passage formed in the casing 14b.
It is connected to the inner peripheral part of the
The end surface 15c of the convex portion 15b on the side is grooved to form the diffuser portion 26a (see FIG. 2).

Therefore, since the diffuser portion 26a can be grooved from the side of the end surface 15c of the convex portion, the machining is easy, and the groove portion is opened. However, when the diffuser portion 26a is assembled with the concave portion 15a of the casing 14a of the first stage, the opening portion is It is sealed by the bottom of the recess.

One end of a rotor shaft 28 of a canned motor unit 12 to be described later is inserted through the central portions of the pump casings 14a and 14b configured as described above, and the impeller 30 is radially arranged as the impeller 30 in the first-stage impeller storage chamber 18. A radial open impeller composed of straight blades is mounted on the shaft, and in the circular pump flow passage 20, scrolls 34, 36 constituted by sliding materials are arranged on both side surfaces of the pump impeller 32, and one scroll 3
4 is fixed to the pump casing 14b, and the other scroll 36 is fixed to a bearing housing 40 that supports a front bearing 38 provided at an end of a canned motor portion 12 described later.

Therefore, an annular pump chamber 42 is formed on the outer peripheral portion of the pump impeller 32 sandwiched by the pair of scrolls 34, 36. A flow passage 44 communicating with the front bearing 38 of the canned motor portion 12 is provided on the center side of the scrolls 34, 36, and the flow passage 44 is a joint surface between the scrolls 34, 36 and the pump impeller 32. Through the gap formed in the pump chamber 42
Communicate with

On the other hand, the canned motor portion is composed of a stator assembly 46 and a rotor assembly 48, and the rotor shaft 28 is supported by a front bearing 38 and a rear bearing 50, respectively.
A front rotor chamber 52 and a rear rotor chamber 54 are provided at both ends of the 48, respectively.
And are formed.

Further, one end of the stator assembly 46 is sealed by a flange-type end plate 56, and a bearing housing 40 supporting a front bearing 38 is provided on a front side surface of the end plate 56.
Is fixed and the pump casing 14 is
a and 14b are integrally coupled and fixed. Meanwhile, stator assembly 4
The other end of 6 is also sealed by an end plate 58, and a bearing housing supporting the rear bearing 50 is fixed to the end plate 58 to seal the rear rotor chamber 54.

In this case, a terminal box 62 for connecting a power source is installed on the outer peripheral portion of the stator assembly 46, and a communication hole 64 is formed in the bearing housing 60 that seals the rear rotor chamber 54 to form an external circulation tube 66. Configure to communicate.

By configuring the impeller in the first-stage pump casing with radial straight blades, the pump performance of the first-stage becomes a pump characteristic diagram as shown in Fig. 3, and the head is constant even if the flow rate changes. Becomes

In FIG. 3, reference numerals indicate pump characteristic curves of the radial straight blades, and reference numerals indicate pump characteristic curves of the radial straight blades.
The NPSHR (necessary suction head) characteristic curve is shown, and the reference numeral shows the NPSHR (necessary suction head) characteristic curve of the vortex type pump.

However, in this embodiment, the first-stage impeller is a radial straight blade, and the discharge flow rate Q of the first-stage pump in this case is, for example, as shown in FIG.
The discharge amount q ₁ of the second-stage vortex flow pump is added to the bypass amount q ₂ introduced into the bypass hole 25 (Q = q ₁ + q ₂ ). Then, as the discharge flow rate of the first-stage pump in this case, the intersection point between the pump characteristic curve and the NPSHR (necessary suction head) characteristic curve of the second-stage vortex flow pump, that is, the flow rate Q ₂ is defined as the maximum flow rate. It becomes the characteristic to do.

Therefore, in this embodiment, even if the flow rate of the second stage vortex flow pump changes, the NPSH of the suction port of this vortex flow pump is changed.
A (effective suction head) is almost constant as is clear from the pump characteristic curve of the impeller composed of the first-stage radial straight blades. That is, by providing the bypass hole 25 in the second-stage pump casing 14a, the gas component at the suction port of the vortex flow pump directly flows through the canned motor portion 12 and flows out to the gas phase portion in the pump suction tank. Or the liquid may partially flow into the low pressure part of the pump part, but the first stage impeller uses a radial open impeller, and the second stage vortex flow is Of the suction port of the mold pump
Does not affect NPSHA (effective suction head).

In general, NPSHR (Net Positive Suction Hea
d Pequired) is the suction performance peculiar to the pump, and the smaller this value, the less likely cavitation occurs. In contrast, NPSHA (Net Positive Suction
Head Available) is determined by the piping conditions (suction pipe, suction pipe length, suction pressure, etc.), and the condition that cavitation does not occur must always be NPSHA> NPSHR.

Next, the operation of the vortex flow type canned motor pump configured as described above will be described.

Rotation of the rotor shaft 28 by the driving of the canned motor causes the radial open impeller 30 and the pump impeller 32 to rotate. As a result, the pump handling liquid is sucked from the suction port 16 under the action of the first stage radial open impeller 30,
It flows into the flow path 26. At this time, the pressure of the liquid is increased by the diffuser portion 26a, and the pump chamber in which the swirl type pump impeller 32 is housed
Guided to the suction port 22 of 42. At this time, a part of the liquid pressurized by the first stage radial open impeller 30 passes through the bypass hole 25, passes through the radial notch 41 of the bearing housing 40, and flows into the front rotor chamber 52.

The liquid flowing into the pump chamber 42 is pressurized in the pump chamber 42 and discharged from the discharge port 24.

In this way, a part of the pump handling liquid whose pressure is increased in the pump chamber 42 flows into the low pressure portion through the flow path 44 from the gap formed between the pump impeller 32 and the scrolls 34, 36.

On the other hand, a part of the liquid that has flowed into the rotor chamber 52 via the bypass hole 25 flows into the inner peripheral surface of the front bearing 38 to lubricate the front bearing 38, and the pump impeller 32 and the scrolls 34, 36 Liquid flowing from the gap formed between
It joins at 4 and pressurizes the pump flow path 20, passes through the bush 19, and returns to the suction part of the first stage radial open impeller 30.

On the other hand, most of the liquid that has flowed into the rotor chamber 52 is guided to the inner peripheral surface of the rear bearing 50 through the gap between the stator and the rotor and the rear rotor chamber 54, and cools the motor portion and lubricates the rear bearing 50. In this way, the pump handling liquid that has lubricated the rear bearing 50 is returned to the pump handling liquid supply tank through the circulation tube 66 that is attached upward from the through hole 64 formed in the bearing housing 64. Let

However, according to the vortex type canned motor pump according to the invention, by configuring the scrolls 34, 36 located on both sides of the vortex type pump impeller 32 with the same sliding material as the bearings 38, 50 (for example, a carbon bearing), It functions as a thrust bearing for the rotor shaft 28 and can facilitate the design of the clearance required for this type of pump. In this case, a part of the pump handling liquid guided into the pump chamber 42 flows into the gap between the pump impeller 32 and the squales 34, 36 to perform lubrication thereof, and at the same time effectively achieve a predetermined gap maintenance. be able to.

In addition, when the night pump is stopped and the pump is started the next morning in summer or winter when the temperature difference is large, the temperature in the suction pipe becomes higher than the liquid temperature in the suction tank, and the vapor pressure in the suction pipe increases. The liquid gasifies in the suction pipe. This gas flows into the first-stage impeller storage chamber 18 via the pump suction port 16, but the front rotor chamber 52 and the rear rotor chamber 54 are successively passed through the diffuser portion 26a, the bypass hole 25, and the cutout portion 41. , Through the through hole 64 and the circulation tube 66, and flows out of the pump section.

By constructing the vortex flow pump in this way, the pump discharge pressure of the first stage passes through the bypass hole 25 and the flow passage 44 and the pump flow which are the low pressure part of the front rotor chamber 52 and the second stage pump. By pressurizing the passage 20, it is possible to prevent cavitation in the gap between the second-stage pump impeller 32 and the scrolls 34 and 36, and in the enlarged portion of the low pressure portion of the pump at the gap outlet, and to reduce noise.

That is, according to the experimental data, the pump specification is 40 / m
In the case of in × 80m; 2.2kw (50Hz), the noise is 73db in the conventional model
What was (A) was 67db in the vortex type pump of the present invention.
It could be reduced to (A).

In order to configure the vortex type canned motor pump according to the present invention so as to be commonly used for different frequency power sources, the flange type end plate 56 and the front bearing 38 are required.
This can be easily dealt with by interposing an annular spacer (not shown) of a predetermined thickness on the joint surface 70 with the bearing housing 40 supporting the.

For example, as shown in FIG. 1, in the case where the one without the annular spacer is designed for 60 Hz, the annular spacer is attached to the joint surface 70 to use the pump impeller 32 when using with a power source of 50 Hz. By adjusting the gap between the scrolls 34 and 36, the pump performance can be kept constant even if the rotation speed of the pump impeller 32 changes.

[Effects of the Invention] As is apparent from the above-described embodiments, according to the vortex type canned motor pump according to the present invention, the pressure of the pump part at the preceding stage passes through the communication passage and the rotor chamber of the canned motor part and the next stage. By configuring so that the low pressure part of the pump part is pressurized, the occurrence of cavitation in the gap between the impeller and the scroll of the next stage pump part and the enlarged part of the low pressure part at this gap outlet is prevented, and noise is reduced. Can be achieved.

Also, by using a radial open impeller consisting of radial straight blades for the impeller in the pump casing of the previous stage, the pump head performance of this stage is constant even if the flow rate changes, therefore the flow rate of the vortex pump Vortex pump NPSHA (effective suction head)
Can always be constant.

Furthermore, by providing a bypass hole communicating with the rotor chamber of the canned motor section in the pump casing of the next stage, the gas component generated in the pump chamber flows out to the gas phase section of the pump suction tank via the inside of the canned motor section. In addition, even if the gas partially flows into the low pressure part of the pump part together with the liquid, by using the radial open impeller in which the impeller of the previous stage consists of radial straight blades, Mouth NPSHA
A vortex pump having stable pump characteristics can be easily designed and manufactured without affecting (effective suction head).

Moreover, all the problems that could not be solved by the conventional vortex type pumps are solved, and it is possible to easily manufacture a pump that fully utilizes the features of the vortex type pump, and it is possible to significantly reduce the manufacturing cost. Have.

The preferred embodiment of the present invention has been described above. However, it is a matter of course that various design changes can be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a flow type canned motor pump according to the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a pump of a first stage pump of the present invention. FIG. 4 is a characteristic diagram, and FIG. 4 is a sectional view of a conventional vortex type canned motor pump. 10 …… Pump section, 12 …… Canned motor section 14a, 14b …… Pump casing 15a …… Concave section, 15b …… Convex section 15c …… Convex section end surface, 16 …… Suction port 18 …… Impeller storage section, 19… … Bush 20 …… Pump flow path, 22 …… Suction port 23 …… Blind plug, 25 …… Bypass hole 24 …… Discharge port, 26 …… Flow path 26a …… Diffuser part, 28 …… Rotor shaft 30 …… Radial open impeller 32 …… Vortex pump impeller 34,36 …… Scroll, 38 …… Front impeller 40 …… Bearing housing 41 …… Notch, 42 …… Pump chamber 44 …… Flow passage, 46 …… Stator assembly 48 …… Rotor assembly, 50 …… Front bearing 52 …… Front rotor chamber, 54 …… Rear rotor chamber 56 …… Flange type end plate 58 …… End plate 60 …… Bearing housing 62 …… Terminal box, 64 …… Through hole 66 …… Circulation tube 70 …… Joining surface

Claims (2)

[Claims] 1. A scroll (34, 36) made of a sliding material is provided on both side surfaces of a swirl type pump impeller (32), and an annular pump chamber (4) is provided on an outer peripheral portion of the swirl type pump impeller.
In a vortex type canned motor pump composed of a pump part (10) formed by connecting a plurality of pump casings (14a, 14b) forming part 2) and a canned motor part (12), inside the pump casing (14a) of the preceding stage. Is provided with a radial open impeller (30) consisting of radial straight blades, a swirl type pump impeller (32) is provided in the pump casing (14b) of the next stage, and the pump discharge port (26a) of the preceding stage is connected to the pump casing (14a, 14b) communicates with the next-stage pump section suction port (22) through the passage (26), and opens toward the pump section suction port side of the next-stage pump casing (14b), and the front bearing (38) Is communicated with the front rotor chamber (52) in the canned motor part (12) through the notch part (41) of the bearing housing (40) of the front part of the canned motor part (12). Viper to introduce to A hole (25) is formed so that the next stage pump discharge liquid is discharged from the discharge port (24) provided in the pump casing (14b), and part of this pump handling liquid is used as the swirl type pump impeller (32). The front rotor in the canned motor part (12) is configured so as to flow into a low pressure part of the pump part (10) through a flow path (44) from a gap formed between the scroll (34, 36). Division (5
A part of the pump handling liquid introduced into 2) is configured to join the flow path (44) through the front bearing (38), and the canned motor part (through the bypass hole (25). The pump handling liquid introduced in 12) is put into the stator assembly (4
6) and rotor assembly (48) through the front rotor chamber (5
A vortex type canned motor pump characterized by being introduced into 4) and communicating with the gas phase part of the pump suction tank via the rear bearing (50). 2. A joint surface (70) between a flange type end plate (56) provided at a coupling portion between a pump portion and a canned motor portion and a bearing housing (40) supporting a front bearing (38) is provided with a predetermined shape. The vortex type canned motor pump according to claim 1, wherein an annular spacer having a thickness is attached so as to adjust a gap between the vortex type pump impeller (32) and the scroll (34, 36).