JPH0681797A - Motor pump connection terminal structure - Google Patents

Abstract

(57) [Abstract] [Purpose] [Constitution] Motor pump terminal connection structure of the present invention (9)
Is a hollow cylindrical housing (25) containing the conductive member (41).
It also has an upper base (37) and a lower base (31), and the power supply side terminals and the motor side terminals (36, 31) are inserted into the housing through the upper base and the lower base. The power supply side terminal and the motor side terminal are electrically connected to the conductive member (41). The motor side terminal (30) is hermetically coupled to the lower base (31) by the seal portion (28, 28A) having the metal sealing ring (33A, 33B; 133A, 133B), and the power source side terminal (36 ) Is the seal part with the gasket (26A-26C) on the upper base (37)
They are joined airtightly by (27).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-pump connection terminal structure, and more particularly to a motor-pump connection terminal structure suitable for application to a motor pump such as a pull-out canned motor pump.

[0002]

2. Description of the Related Art A pump which sucks and discharges a flammable and dangerous liquid such as liquefied gas and liquefied ammonia is a pump that stores the liquid in order to prevent the liquid from leaking. It has a pull-out structure that can be placed in a tank and can deliver liquid through a column pipe.

This pump of the pull-out type structure usually uses an immersion type motor, but when the liquid to be handled is a liquid that corrodes copper such as liquefied ammonia, the purpose is to prevent corrosion of the copper wire. A canned motor is adopted as. Usually, a pump in which a pump and a canned motor are integrally formed is called a canned motor pump.

Such a canned motor pump is a connection for connecting the motor-side conductive cable drawn from the motor in the motor pump unit and the power-side conductive cable drawn from the power supply installed outside the storage tank. It has a terminal. This connection terminal is usually installed in the casing of the canned motor pump. Therefore, since the canned motor pump is immersed in the liquid, this connection terminal is also immersed in the liquid.

This connection terminal uses a gasket because it is required to have an airtight structure so that a corrosive liquid such as liquefied ammonia does not enter the inside, and moreover, a gasket is used, and moreover, a power source side arranged in the connection terminal structure. The terminal element of the conductive cable is formed of aluminum or stainless steel which is not easily corroded by liquefied ammonia or the like. The main part of a conventionally known connection terminal structure using a gasket will be described with reference to FIG.

The connection terminal 50 shown in the figure has connection terminal elements 52, 54 made of aluminum or stainless steel fixed to the respective ends of the conductive cable 51 on the power source side and the conductive cable 53 on the canned motor pump side. The connection terminal 50 has copper terminal pins 55 at both ends thereof, to which connection terminal elements 52 and 54 are connected by bolts or screws. The terminal pin 55 has a through hole provided in a stainless steel terminal plate 56, and an electric insulator 57 and a terminal pin 55 disposed therein.
And a gasket 63 arranged between the electric insulator 57 and between the electric insulator 57 and the terminal plate 57.
It penetrates and extends via a and 63b.

Further, the flange portion 58a of the upper pipe 58 is joined to the upper surface of the terminal plate 56, and the flange portion 59a of the lower pipe 59 is joined to the lower surface of the terminal plate 56 with the gasket 60 interposed. Then, the flange portions 58a, 59 are fixed by the bolts 61.
By tightening a, the terminal pin 55 penetrating the terminal plate 56 is enclosed.

A filling material 62 such as an epoxy resin is filled inside the upper pipe 58 and the lower pipe 59.

However, the gaskets 63a and 63b used in the connection terminal 50 cannot secure sufficient airtightness, and high-pressure ammonia or the like on the discharge side of the canned motor pump cannot be secured, for example, on the terminal plate 56 and the flange. A small gap with the portion 58a is infiltrated, and the infiltrated high-voltage anminia is electrically insulated 57 and gasket 63.
The gap between a and 63b and other members further infiltrate, and finally liquefied ammonia infiltrates into the motor portion of the canned motor pump. As a result, if high-pressure ammonia or the like penetrates into the canned motor pump, it causes damage to the motor portion due to corrosion, and has a great influence.

[0010] On the other hand, the utility model application publication No. 909, 1991
In JP-A-6, unlike a liquefied ammonia, a gas-tight connection terminal structure applied to a canned motor pump used in a storage tank storing a liquid such as liquefied natural gas or liquefied propane gas that does not need to consider corrosion on copper. Is proposed.

In the airtight connection terminal structure described in the above publication, a ceramic terminal element having a copper conductor penetratingly held is inserted into a terminal insertion hole formed in a terminal block provided in a casing of a motor pump unit, A metal ring is interposed between the ceramic terminal element and the terminal block and between the ceramic terminal and the copper conductor, and the metal ring is brazed or fixed to the ceramic terminal element, the terminal block and the copper conductor. It has a fixed structure. Then, such an airtight connection terminal structure is housed in a housing provided in the casing of the canned motor pump. However, the airtight connecting terminal structure described in the above publication has a very high airtightness because the gap between the ceramic terminal and the conductor and the gap between the ceramic terminal and the terminal block are sealed with metal or brazed. Can be realized.

However, the airtight connection terminal structure described in the above publication cannot be immediately applied to a canned motor pump that handles corrosive liquids such as liquefied ammonia having a high corrosiveness to copper.

This is because even if the airtight connection terminal structure itself has high airtightness, if the corrosive liquid penetrates into the housing accommodating the airtight connection terminal structure, the copper conductor is corroded. The airtightness of the airtight terminal is thereby impaired.

However, it is difficult to replace the conductor in the airtight connection terminal structure with a metal such as aluminum having corrosion resistance against liquefied ammonia. This is because a technique for easily fixing a metal ring to a conductive metal such as aluminum by brazing or welding the metal has not been found yet.

Therefore, the airtight connection terminal structure proposed by the applicant cannot be applied to a connection terminal of a canned motor pump immersed in a corrosive liquid such as liquefied ammonia, and the above gasket is used. The only way is to ensure airtightness. Further, in the connection terminal using the gasket, as described above, there is a limit in ensuring the airtightness, and there is a problem such as causing a failure of the pump.

An object of the present invention is to provide a connecting terminal structure for a motor pump having a highly airtight structure capable of preventing intrusion of a highly corrosive liquid such as liquefied ammonia into copper.

[0017]

The invention according to claim 1 for solving the above problems is provided in a casing of a motor pump arranged in a storage tank for liquid ammonia or a liquid similar thereto, and A lower base arranged in the casing at a connection terminal for connecting a first conductive cable supplying a current to a motor in the motor pump and a second conductive cable supplying a current from a power source, and the lower base being airtight A tubular body having a first opening end closed to the inside and an upper closing member that hermetically closes the second opening end of the tubular body, and a first through hole provided in the lower base. A motor-side terminal electrically connected to a first conductive cable for supplying current to the motor in the motor pump, which is held airtightly and insulatively by a sealed metal, and an upper part Airtightly through the gasket into the second through hole provided in the chain member, and a supply of at held in an insulated state, and the current from the spaced supply 2
A power supply side terminal, which is provided at the tip of the conductive cable, is made of a metal that is resistant to corrosion by liquefied ammonia or a liquid similar thereto, and the power supply side terminal is arranged in the housing and connects the motor side terminal and the power supply side terminal. The connection terminal structure according to claim 2, wherein the power supply side terminal of the corrosion-resistant metal is made of aluminum or stainless steel. The connection terminal structure of the motor pump according to claim 3, wherein the invention of claim 3, wherein the electrically insulating tubular body is inserted through the through hole provided in the lower base, A sealing member is airtightly coupled to the through hole, the motor-side terminal is inserted into the electrically insulating tubular body, and
The connection terminal structure for a motor pump according to claim 1, which is hermetically sealed with a metal sealing member, and the invention according to claim 4 is characterized in that the first and second metal sealing members are both First and second metal sealing rings made of a Ni-Co-Fe alloy, the first metal sealing ring being airtightly coupled to the lower base by welding and being airtight to the tubular body by brazing. 4. The motor pump according to claim 3, wherein the second metal sealing ring is airtightly joined to the cylindrical body by brazing and is also airtightly joined to the motor side terminal by brazing. A connection terminal structure, wherein the invention according to claim 5 is the connection terminal structure for a motor-pump according to claim 1, wherein the space in the housing is filled with an inert gas. The invention according to claim 5 is the connection terminal structure for a motor pump according to claim 5, wherein the inert gas is at least one of nitrogen gas and rare gas or a mixed gas thereof. The connection terminal of the motor pump according to claim 1, wherein the housing is filled with a filling material.

[0018]

The connection terminal structure of the motor pump according to the present invention is such that the terminal of the motor side power cable is sealed with a metal seal on the lower base of the housing, and the power side cable is connected to the upper closing member of the housing. Since the double-sealed structure in which the corrosion-resistant metal terminal provided at the tip of the is sealed using a gasket, the intrusion of corrosive liquid into the housing is prevented.

[0019]

EXAMPLES Examples of the present invention will be described in detail below.

First, the installation state of the canned motor pump 1 as a motor pump will be described with reference to FIG.

This canned motor pump 1 is arranged at the bottom of a column pipe 2 arranged in a storage tank for storing a liquid having corrosiveness against copper such as liquefied ammonia gas.

That is, the canned motor pump 1 is suspended by the lift cable 4 and the suspension fitting 5 suspended from the head plate 3 installed on the upper end of the column pipe 2.

The canned motor pump 1 can be pulled up from the bottom of the column pipe 2 by removing the head plate 3 and then winding the lift cable 4 with a winch (not shown), for example. By paying out the lift cable 4 with, it can be placed on the bottom surface of the column pipe 2.

A foot valve 6 and a foot valve adapter 7 are provided at the bottom of the column pipe 2. The foot valve 6 is attached to the foot valve adapter 7 so that it is always in contact with the foot valve adapter 7 by a coil spring (not shown). In other words, when the canned motor pump 1 is suspended above the bottom of the column pipe, the foot valve 6 is forcibly brought into contact with the foot valve adapter 7 by the coil spring, and the bottom opening of the column pipe is closed. become. Then, when the suspended canned motor pump 1 reaches the bottom of the column pipe 2 and hits the foot valve 6, the weight of the canned motor pump 1 pushes down the foot valve 6 against the coil spring, and the foot valve 6 and the foot valve 6 are pushed down. A gap is created with the valve adapter 7. Then, the liquid in the storage tank can flow into the column pipe 2 through this gap.

Energization of the canned motor pump 1 is as follows.
In the connection terminal structure 9, the terminal of the conductive cable 10 introduced inside through the opening provided in the head plate 3 is electrically connected to the motor section 12 in the canned motor pump 1 and the conductive cable on the motor side is connected. It is performed by electrically connecting to the terminal.

As shown in FIG. 1, the liquid in the storage tank is sucked by the canned motor pump 1 through the gap between the foot valve adapter 7 and the foot valve 6, and discharged in the flow path indicated by the arrow in FIG. It is designed to discharge from the outlet 8 toward a target location.

The canned motor pump 1 is provided with a motor section 12 and a pump section 13, as shown in an enlarged scale in FIG.

The motor unit 12 has a drive shaft 15 rotatably arranged in a casing 14, a stator 16 attached to the drive shaft 15, and a rotor 18 having windings 17 arranged on the outer periphery of the stator 16. A connection terminal base 19 forming a part of the casing, which has a through hole communicating with the inside of the casing 14 provided at the upper end of the casing 14, and the connection terminal 9 attached to the connection terminal base 19. It is equipped with.

The pump portion 13 is mounted on the lower end portion of the drive shaft 15, an impeller 21 mounted on the drive shaft 15 above the inducer 20, and arranged above the impeller 21. The diffuser 22, the balance mechanism 23 arranged at the boundary with the motor unit 12, and the liquid discharge port 24 (only one discharge port is shown) are provided.

Here, the connection terminal 9 will be described in detail with reference to FIG.

The connection terminal 9 has a substantially cylindrical double seal structure.

That is, the connection terminal 9 has a power source side seal portion 27 using gaskets 26A and 26B and a motor side seal portion 28 having a metal seal structure at both ends of a tubular body 25 made of a non-corrosive metal such as stainless steel. Is provided.

As shown in FIGS. 2 and 3, the motor-side seal portion 28 is a motor-side terminal and is made of metal, for example, copper terminal 30, and a non-conductive tubular body, for example, ceramic tubular body 30A. A lower terminal plate 31 made of a non-corrosive metal such as stainless steel, which is a lower base, a lower flange portion 25a made of a non-corrosive metal such as stainless steel, and a spacer 32,
It has two metal seal rings 33A and 33B.

The copper terminal 30 is an electrical connection member 2
By 9A, one end is connected to the other end of the motor-side conductive cable 29 whose one end is connected to the winding 17 of the stator 18. The lower terminal plate 31 is arranged on the connection terminal base 19 and has a through hole 31A that is a first through hole. The through hole 31A holds the ceramic cylindrical body 30A in a penetrating state. Further, the copper terminal 30 penetrates through the ceramic cylinder 30A. An annular notch 31A-1 having a diameter larger than the diameter of the through hole 31A is formed in the opening of the through hole 31A on the surface of the lower terminal plate 31 facing the connection terminal base 19. This notch 31
A ring-shaped metal seal ring 33A whose both ends are bent in the same direction and whose longitudinal section is substantially U-shaped is fitted to A-1. The metal seal ring 33A is welded to the lower terminal plate 31, and the cylindrical body 3 made of ceramics.
It is brazed to 0A. This metal seal ring 33A
Lower terminal plate 3 by welding and brazing
By fixing it to No. 1, it is possible to completely seal the through hole 31A in the lower terminal 31 and the ceramic cylindrical body 30A.

As shown in FIG. 2, the lower flange portion 25A is formed at the lower end portion of the tubular body 25, is disposed on the upper surface of the lower terminal plate 31 via a gasket, and has a bolt 34 (see FIG. 2). Is attached to the lower terminal plate 31. The spacer 32 is attached to the inner surface side and the bottom surface side of the lower flange portion 25A so as to close the inside of the tubular body 25. The spacer 32 is also provided with a through hole 32A, and the ceramic cylindrical body 30A passes through the through hole 32A.

In other words, the cylindrical body 30A made of ceramics
Is firmly fixed by penetrating the through hole 31A of the lower terminal plate 31 and the through hole 32A of the spacer 32.

The end of the copper terminal 30 projects from the tip opening of the ceramic cylindrical body 30A projecting from the through hole 32A of the spacer 32.
Are coupled to a rod-shaped conductor 41 that is a conductive member.
Ceramic cylinder 30A protruding from the through hole 32A
An annular metal seal ring 33B, which has a cup-shaped cross section with both ends bent in opposite directions, is attached to the tip of the terminal with the copper terminal 30 fitted in the central opening. The metal seal ring 33B is fixed to the ceramic cylinder 30A by brazing, and also fixed to the copper terminal 30 by brazing. By brazing the metal seal ring 33B, the gap between the ceramic cylinder 30A and the copper terminal 30 can be completely sealed.

In the present invention, the motor side seal portion 2
In addition to the above-described configuration, the configuration of 8 may be configured as follows.

As shown in FIG. 4, the motor side seal portion 28
A is a terminal 30 made of copper, which is mounted in a through hole 131A provided in a lower terminal plate 131 made of a corrosion resistant metal such as stainless steel, a cylindrical body 130A made of an insulating material such as a ceramic, and a lower terminal plate 131. It has a first metal seal ring 133A for sealing the ceramic tubular body 130A, and a second metal seal ring 133B for sealing the ceramic tubular body 130A and the copper terminal 30.

The first metal seal ring 133A is used.
The second metal seal ring 133B is made of, for example, Ni.
-Co-Fe type alloy is used.

As shown in FIG. 4, the through hole 131A provided in the lower terminal plate 131 is formed in the casing 1
First circular recess 131A-1 opening on the surface of the lower terminal plate 131 on the 9th side, and the first circular recess 131
Opened on the bottom of A-1, lower terminal plate 13
No. 1 casing 19 and a cylindrical through hole 131A-2 penetrating the surface on the opposite side. First circular recess 131A-
1 and the cylindrical through hole 131A-2 have a relationship of sharing the same central axis. The annular recess 131A-3 is the casing 1.
It is formed on the surface of the terminal plate 131 on the 9 side so as to share the same center as the first circular recess 131A-1. The inner diameter of the annular recess 131A-3 is equal to that of the first circular recess 13
1A-1 has an outer diameter larger than that of the annular recess 131A-3 and the first circular recess 131A-1.
They are separated by a small distance via an annular protrusion 131A-4 forming a part of 31.

An annular protrusion 30-1 having a diameter larger than that of the terminal 30 is formed at the base of the copper terminal 30 near the motor-side cable 29. The copper terminal 30 is coupled to the motor-side conductive cable 29 by an appropriate electrical coupling means 29A.

The ceramic cylindrical body 130A has an outer peripheral portion 130A-1 having a diameter larger than the diameter of the other outer periphery at the center of the outer periphery thereof.

The copper terminal 30 is inserted into the through hole 131A in a state where the copper terminal 30 is inserted into the ceramic cylindrical body 130A, and the outer peripheral portion 130A-1 of the ceramic cylindrical body 130A is inserted. The outer surface is brazed to the inner surface of the first metal seal ring 133A to form a seal. This seal has a through hole 13
1A is inserted until the upper end of the large-diameter outer peripheral portion 130A-1 reaches the bottom of the first circular recess 131A-1 in the lower terminal plate 131. First circular recess 131A
The inner diameter of -1 is determined so that the seal portion configured by the cylindrical body 130A made of ceramics and the first metal seal ring 133A can be smoothly inserted.

The axial length of the first metal seal ring 133A is designed to be the length from the bottom of the first circular recess 131A-1 to the surface of the lower terminal plate 131 on the casing 19 side. Therefore, the seal portion is the first circular recess 13
When correctly inserted into 1A-1, the outer end of the first metal seal ring 133A in the axial direction becomes flush with the annular end surface of the annular protrusion 131A-4 of the lower terminal plate 131. The axial outer end of the first metal seal ring 133A and the annular protrusion 131A-4 are fixed by brazing.

As described above, the ceramic cylindrical body 1
30A and the first metal seal ring 133A are brazed, and the first metal sealing ring 133A and the lower terminal 131 are welded to each other, whereby the ceramic cylinder 130A, the first metal sealing ring 133A, and the lower terminal plate 31. Is completely integrated and the seal is perfect.

On the other hand, the rear end portion of the ceramic cylindrical body 130A into which the terminal 30 is inserted is in contact with the edge of the annular protruding portion 30-1 of the terminal 30. The ring-shaped second metal seal ring 133B is arranged so as to cover the joint portion between the ring-shaped protrusion 30-1 and the bottom end of the ceramic cylinder 130A. The second metal seal ring 133B and the annular protrusion 30-1 are sealed and joined by brazing,
The second metal seal ring 133B and the ceramic cylinder 130A are sealed and joined by brazing. Therefore, the ceramic cylinder 130A and the copper terminal 30 are completely sealed together.

The power supply side seal portion 27 is well shown in FIGS. 2 and 5.

The power supply side seal portion 27, which is a power supply side terminal, is a terminal 36 made of metal such as stainless steel, which is resistant to corrosive liquids such as liquefied ammonia.
A connecting member including the socket 36A and the nut 36B, a first gasket 26A and a second gasket 26B made of a non-conductive material such as Teflon, and a tubular body 26c made of a non-conductive material such as Teflon (registered trademark). Have.

The socket 36A has a flange portion 36C at one end.
And a screw 36A-3 formed on the outer peripheral surface of the other end of the shaft 36A-1.

The first gasket 26A and the second gasket 26B are respectively the shaft 36A-1 of the socket 36A.
Is an annular plate-like body having an inner diameter substantially the same as the outer diameter of. Further, the Teflon cylinder 26C is provided on the upper terminal plate 37 which is an upper base made of a metal such as a stainless steel which has substantially the same inner diameter as the outer diameter of the shaft 36A-1 of the socket 36A and which is corrosion resistant. The outer diameter is substantially the same as the inner diameter of the through hole 37A (which is the second through hole).

The terminal 36 made of stainless steel is the socket 36.
It is inserted through A. The second gasket 26B has a shaft 36
It is inserted into A-1 and placed on the saliva 36A-2.
The tubular body 26C is arranged on the outer periphery of the shaft 36A-1 to form an assembly of the socket and the gasket. The assembly of this socket and the gasket is the shaft 36A-1.
Is inserted into the through hole 37A of the upper terminal plate 37 until the second gasket 26B comes into close contact with the lower surface of the upper terminal plate 37. Then, the first gasket 26A and the washer 26D are fitted and inserted into the portion of the shaft 36A-1 that protrudes upward. Then nut 3
6B is screwed onto the outer periphery of the upper protruding portion of the shaft 36A-1 of the socket 36A, and the first and second gaskets 26
The A and 26B are tightened so as to mesh with the upper and lower surfaces of the upper terminal plate 37 and the upper and lower ends of the resin cylindrical body 26C. This allows the upper terminal plate 37
The sealing of the through hole 37A at is completed.

The upper terminal plate 37 is the cylindrical body 2
The gasket 26 is placed on the upper end of the sheet 5 and placed.
The upper terminal plate 37 is coupled to an upper flange 25B formed on the upper end of the tubular body 25 with a bolt 39 (only one is shown in the drawing). The upper terminal 36 is
It is protected by a cover member 38 attached to the upper terminal plate 37 with bolts (only one is shown in the drawing).

The copper terminal 30 and the stainless steel terminal 36 are connected in the tubular body 25 by a conductor 41 in a screw structure.

Further, the inside of the tubular body 25 has a gas introducing portion 42 provided on the side wall of the tubular body 25. The gas introduction part 42 is connected to a gas introduction pipe (not shown) equipped with a pressure gauge (not shown) on the way, and an inert gas such as N ₂ gas is introduced into the tubular body 25. It is like this. In addition, instead of introducing the inert gas, a filler such as a silicone resin may be filled from the gas introducing unit 42. In short, as long as the air containing water or moisture can be removed from the inside of the tubular body 25, it may be filled with an inert gas or may be filled with a filler. .

Further, the side wall of the tubular body 25 is provided with a gas discharge part 43 for connecting an opening / closing valve (not shown) so that the N ₂ gas introduced from the gas introduction part 42 can be discharged. There is.

Next, the operation of the above-described canned motor pump 1 will be described mainly by the operation of the connection terminal 9.

Connection terminal 9 of this canned motor pump 1
According to this, the lower terminal plate 31 made of non-corrosive metal such as stainless steel, the upper terminal plate 37 made of non-corrosive metal such as stainless steel, and the tubular body 25 made of non-corrosive metal such as stainless steel form the casing. Therefore, even if it comes into contact with a corrosive liquid such as liquefied ammonia flowing in the column pipe 2, these do not corrode.

Further, the power supply side seal portion 27 is the gasket 2
6A, 26B is used as the sealing structure, and the motor-side sealing portion 28 is made of a ceramic cylindrical body 30A or 130A.
And a metal seal ring 33A, 33B, or 133A,
Since the seal structure using 133B is used, a high sealing function can be secured and substantial leakage of corrosive liquid can be prevented.

Further, when the N ₂ gas is introduced into the tubular body 25 from the gas introduction portion 42 provided on the side wall of the tubular body 25 to perform N ₂ gas purging, the tubular body 25 It is possible to prevent an electric leakage phenomenon caused by a dew condensation phenomenon that occurs when air is present in the body 25.
Further, by keeping the purged N ₂ gas at a pressure equal to or higher than the pressure inside the column pipe, liquid leakage from the power supply side seal portion 27 can be suppressed.

Further, by monitoring the pressure inside the tubular body 25 with a pressure gauge connected to the N ₂ gas introducing pipe, it is possible to detect the leakage of the liquid and the canned motor pump arranged in the liquid. The reliability of 1 can be improved.

The present invention is not limited to the above-described embodiments, but various modifications can be made within the scope of the gist thereof.

[0063]

According to the present invention described in detail above, since it has the above-mentioned structure, the leak of corrosive liquid can be eliminated by the double seal structure, and the insulating gas or the insulating material can be connected to the connecting terminal. It is possible to provide a motor-pump connection terminal capable of eliminating substantial leakage and ensuring high reliability.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a canned motor pump according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view showing a connection terminal structure of a canned motor pump according to this embodiment.

FIG. 3 is an enlarged partial vertical cross-sectional view showing how the motor-side terminals are attached to the housing in the connection terminal structure of the canned motor pump of this embodiment.

FIG. 4 is a partially enlarged vertical cross-sectional view showing another example of how the motor-side terminals are attached to the housing in the connection terminals of the canned motor pump of this embodiment.

FIG. 5 is a partially enlarged vertical sectional view showing a mounting state of the power supply side terminal to the housing in the airtight terminal of the canned motor pump of the present embodiment.

FIG. 6 is a cutaway perspective view showing an installed state of the canned motor pump of the present embodiment.

FIG. 7 is a partially enlarged cross-sectional view showing a conventional airtight terminal.

[Explanation of symbols]

1 ... Canned motor pump, 2 ... Column pipe, 3 ... Head plate, 4 ... Lift cable, 5 ... Hanging metal fitting, 6 ... Foot valve, 7 ...
-Foot valve adapter, 8 ... Discharge port, 9 ... Connection terminal structure, 10 ... Conductive cable, 12 ... Motor part, 13 ... Pump part, 14 ... Casing, 1
5 ... Drive shaft, 16 ... Stator, 17 ... Winding, 18 ... Rotor, 19 ... Connection terminal base, 20
... Inducer, 21 ... Impeller, 22 ...
Diffuser, 23 ... Balance mechanism, 24 ...
Liquid discharge port, 25 ... Cylindrical body, 25A ... Lower flange part, 25B ... Upper flange, 26A, 26B
... Gasket, 26C ... Cylindrical body, 26D ... Washer, 27 ... Power supply side seal part, 28,28A ...
..Motor side seal part, 29 ... Motor side conductive cable, 29A ... Electrical connection member, 30 ... Copper terminal, 30-1 ... Annular protrusion part, 30A ... Ceramics Cylindrical body, 31 ... Lower terminal plate, 3
1A ... through hole, 31A-1 ... annular notch, 32 ... spacer, 32A ... through hole, 33
A, 33B ... Metal seal ring, 34 ... Bolt, 36 ... Stainless terminal, 36A ... Socket, 36B ... Nut, 36A-1 ... Hollow shaft, 36A-2・ ・ ・ Saliva, 36A-3 ・ ・ ・ Screws, 3
7 ... Upper terminal plate, 37A ... Through hole, 38 ... Cover member, 39 ... Bolt, 41 ...
..Conductors, 42 ... Introducing section, 43 ... Gas discharging section,
130A ... Ceramic cylinder, 131 ... Lower terminal plate, 131A ... Through hole, 131A
-1 ... 1st circular recessed part, 131A-2 ... cylindrical through-hole, 131A-3 ... annular recessed part, 131A-4 ...
Annular protrusion 133A ... first metal seal ring, 1
33B ... second metal seal ring,

Claims (7)

[Claims] 1. A first conductive cable, which is provided in a casing of a motor pump arranged in a storage tank for liquefied ammonia or a liquid similar thereto, and which supplies a current to a motor in the motor pump, and a current is supplied from a power source. In a connection terminal for connecting a second conductive cable to be supplied, a lower base arranged in the casing, and a tubular body having a first open end hermetically closed by the lower base,
A casing having an upper closing member that hermetically closes the second opening end of the tubular body, and a first through hole provided in the lower base are hermetically held by a sealing metal and in an insulating state. However, the motor-side terminal electrically connected to the first conductive cable for supplying current to the motor in the motor pump and the second through hole provided in the upper closing member are hermetically and insulated via the gasket. A power supply side terminal that is held in a state and is provided at the tip of a second conductive cable that supplies a current from a remote power supply, the power supply side terminal being made of a metal that is resistant to corrosion by liquefied ammonia or a liquid similar thereto; A connection terminal structure, wherein the connection terminal structure is arranged inside the body and has a conductive member that connects the motor side terminal and the power source side terminal. 2. The connection terminal structure for a motor pump according to claim 1, wherein the power supply side terminal of the corrosion resistant metal is made of aluminum or stainless steel. 3. The electrically insulating cylindrical body is inserted and arranged in the through hole provided in the lower base and is airtightly coupled to the through hole by a first metal sealing member, and the motor side terminal is provided. The connection terminal structure for a motor pump according to claim 1, wherein the is inserted into the electrically insulating tubular body and is hermetically sealed by a second metal sealing member. 4. The first and second metal sealing members are first and second metal sealing rings made of a Ni—Co—Fe alloy, and the first metal sealing ring is a lower base. Is welded to the cylindrical body by welding, and is brazed to the cylindrical body by brazing.
The connection terminal structure of the motor pump according to claim 3, wherein the metal sealing ring is airtightly joined to the cylindrical body by brazing and is airtightly joined to the motor side terminal by brazing. 5. The connection terminal structure for a motor pump according to claim 1, wherein the space in the housing is filled with an inert gas. 6. The connection terminal structure for a motor pump according to claim 5, wherein the inert gas is at least one of nitrogen gas and rare gas or a mixed gas thereof. 7. The connection terminal for a motor pump according to claim 1, wherein the inside of the casing is filled with a filling material.