JP2817825B2 - Motor pump connection terminal structure - Google Patents

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 use in a motor pump such as a pull-out canned motor pump.

[0002]

2. Description of the Related Art A pump for inhaling and discharging a flammable or dangerous liquid such as liquefied gas, liquefied ammonia or the like is provided with a pump that stores the liquid in order to prevent leakage of the liquid. It has a draw-out type structure that can be arranged in a tank and can send liquid through a column pipe.

[0003] The draw-out type pump usually uses an immersion type motor. 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. Is used as a canned motor. Usually, a pump in which a pump and a canned motor are integrally formed is called a canned motor pump.
Can be done .

Such a canned motor pump has a connection for connecting a motor-side conductive cable drawn from a motor in a motor pump unit to a power-side conductive cable drawn from a power source installed outside a storage tank. It has terminals. This connection terminal is usually installed on 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.

[0005] The connection terminals on the need to liquids having corrosive such as liquefied ammonia is airtight structure that does not enter the inside, and with a gasket, yet power supply side which is placed on the connecting terminal structure The terminal element of the conductive cable is made of aluminum or stainless steel that is not easily corroded by liquefied ammonia or the like. The principal part of a conventionally known connection terminal structure using a gasket will be described with reference to FIG.

The connection terminal 50 shown in FIG. 1 has connection terminal elements 52 and 54 made of aluminum or stainless steel fixed to the respective ends of the conductive cable 51 on the power supply side and the conductive cable 53 on the canned motor pump side. The connection terminal 50 has copper terminal pins 55 to which connection terminal elements 52 and 54 are connected at both ends by bolts or screws. Terminal pin 55, a through hole provided in a stainless steel terminal plate 56, an electrical insulator 57 and capacitor Minarupin 5 5 disposed therein
Placed a gasket 63a between the between the electrical insulator 57 and the Terminal plates 5 6, via 63 b, extending therethrough.

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

The interior of the upper and lower pipes 58 and 59 is filled with a filler 62 such as epoxy resin.

However, the gaskets 63a and 63b used in the connection terminals 50 cannot ensure sufficient airtightness, and the high-pressure ammonia or the like on the discharge side of the canned motor pump is, for example, connected to the terminal plate 56 and the flange. penetrates into a slight gap between the parts 58a, entering the high pressure Anminia is or electrical insulator 57 gasket 6
3a, further enters the gap between 63b and the other member, and finally liquefied ammonia resulting in entering the motor portion of the canned motor pump. As a result, if high-pressure ammonia or the like infiltrates the canned motor pump, it causes damage to the motor unit due to corrosion, which has a great effect.

[0010] On the other hand, the publication of utility model application publication No. 909/1991
In Japanese Patent Application Publication No. 6-264, an airtight connection terminal structure applied to a canned motor pump used for a storage tank storing liquid such as liquefied natural gas and liquefied propane gas which does not need to consider corrosion to copper unlike liquefied ammonia Has been proposed.

[0011] The hermetic connection terminal structure described in the above publication is characterized in that a ceramic terminal element penetrating and holding a copper conductor 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 welded to the ceramic terminal element, the terminal block and the copper conductor. It has a fixed structure. And such an airtight connection terminal structure is accommodated in a housing provided in a casing of the canned motor pump. The hermetic connection terminal structure described in the above-mentioned gazette is very difficult 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. High airtightness can be realized.

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

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

However, it is difficult to replace the conductor in the hermetic connection terminal structure with a metal such as aluminum having corrosion resistance to liquefied ammonia. This is because a technique for simply 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 present applicant cannot be applied to the connection terminal of a canned motor pump immersed in a corrosive liquid such as liquefied ammonia. The only thing to do is to ensure airtightness. And, as described above, the connection terminal using the gasket has a limit in ensuring airtightness, and has a problem of causing a failure of the pump.

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

[0017]

According to a first aspect of the present invention, there is provided a motor pump casing provided in a storage tank for liquefied ammonia or a liquid similar thereto, and A connection terminal for connecting a first conductive cable for supplying a current to the motor in the motor pump and a second conductive cable for supplying a current from a power supply; A housing having a cylindrical body having a first opening end closed at a first end, an upper closing member for hermetically closing a second opening end of the cylindrical body, and a housing for supplying a current to a motor in the motor pump. (1) a motor-side terminal electrically connected to the conductive cable and held in a first through-hole provided in the lower base in an airtight and insulated state; Liquefied ammonia or a liquid similar to that provided at the end of a second conductive cable which is held in a gas-tight and insulated state through a gasket in a second through hole and which supplies current from a remote power source A power supply side terminal made of a corrosion-resistant metal, and a conductive member disposed in the housing and connecting the motor side terminal and the power supply side terminal. The invention according to claim 2 is the motor pump connection terminal structure according to claim 1, wherein the power-supply-side terminal of the corrosion-resistant metal is made of aluminum or stainless steel. According to the invention described above, an electrically insulating tubular body is inserted through the through-hole provided in the lower base, is airtightly coupled to the through-hole by a first metal sealing member, and the motor-side terminal is And said Is inserted through the gas-insulating cylindrical body, and a connecting terminal structure of the motor pump according to claim 1 comprising air-tightly sealed by a second metal sealing member, the invention according to claim 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 hermetically sealed to a lower base by welding. coupled hermetically by brazing to the tubular body while being coupled to said second metallic sealing ring is air-tight by the motor-side terminal and brazed together is hermetically bonded by brazing to the tubular body 4. The method according to claim 3, wherein
6. A connection terminal structure for a motor pump according to claim 5.
The invention described in (1) is the connection terminal structure of the motor pump according to the above (1), wherein the space inside the housing is filled with an inert gas. The connection terminal structure of the motor pump according to claim 5, wherein the connection terminal structure is at least one of nitrogen gas, a rare gas, or a mixed gas thereof. The connection terminal structure for a motor pump according to claim 1, wherein the connection terminal structure is filled with an insulating material.

[0018]

According to the connecting terminal structure of the motor pump according to the present invention, the terminal of the motor-side power cable is hermetically and insulatedly sealed on the lower base of the housing. Since the terminal of the corrosion-resistant metal provided at the end of the power supply side cable has a double seal structure in which the terminal is sealed using a gasket, penetration of the corrosive liquid into the housing is prevented.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail.

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

The canned motor pump 1 is disposed at the bottom of a column pipe 2 disposed in a storage tank for storing a liquid having a corrosive property to copper such as liquefied ammonia gas.

That is, the canned motor pump 1 is hung by a lift cable 4 and a hanger 5 hung from a head plate 3 installed at the upper end of a column pipe 2.

The canned motor pump 1 can be lifted from the bottom of the column pipe 2 by removing the head plate 3 and winding up the lift cable 4 with, for example, a winch (not shown). The lift cable 4 can be put on the bottom surface of the column pipe 2 by feeding the lift cable 4.

A foot valve 6 and a foot valve adapter 7 are provided at the lowermost part of the column pipe 2. The foot valve 6 is attached to the foot valve adapter 7 so as to always contact the foot valve adapter 7 by the coil spring shown in FIG . 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, so that the bottom opening of the column pipe is closed. become. 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 A gap is formed between the valve adapter 7 and the valve adapter 7. Then, the liquid in the storage tank can flow through the column pipe 2 through the gap.

The energization of the canned motor pump 1 is as follows.
The terminal of the conductive cable 10 introduced into the inside through the opening provided in the head plate 3 is connected to the motor-side conductive cable electrically connected to the motor unit 12 in the canned motor pump 1 in the connection terminal structure 9. This is done by electrically connecting the terminals.

Then, 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 is discharged through the flow path indicated by the arrow shown in FIG. The liquid is discharged from the outlet 8 toward a destination.

The canned motor pump 1 includes a motor section 12 and a pump section 13 as shown in FIG.

The motor unit 12 includes a drive shaft 15 which is rotatably disposed in the casing 14, and b over data 16 attached to the drive shaft 15, a winding 17 arranged on the outer periphery of the b over data 16 and stearyl over data 18, where having a through hole communicating in the casing 14 provided on the upper portion of the casing 14, a connection terminal base 19 forming part of the casing, attached to the connection terminal base 19 And the connection terminal 9.

The pump section 13 includes an inducer 20 attached to the lower end of the drive shaft 15, an impeller 21 attached to the drive shaft 15 above the inducer 20, and an upper part of the impeller 21. A diffuser 22, a balance mechanism 23 disposed at a boundary between the motor 12 and a liquid discharge port 24 (only one discharge port is shown).

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 is provided at both ends of a cylindrical body 25 made of a non-corrosive metal such as stainless steel, with a power supply side seal portion 27 using gaskets 26A and 26B and a motor side seal portion 28 having a metal seal structure. Is provided.

As shown in FIGS. 2 and 3, the motor-side seal portion 28 includes a metal-side terminal 30 made of metal such as copper and a non-conductive tube-like body 30A made of ceramics. A non-corrosive metal such as stainless steel lower terminal plate 31 serving as a lower base, a non-corrosive metal such as stainless steel lower flange portion 25a, and a spacer 32;
It has two metal seal rings 33A and 33B.

The copper terminal 30 is connected to the 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 disposed on the connection terminal base 19 and has a through hole 31A as a first through hole. The through-hole 31A holds the cylindrical body 30A made of ceramics while penetrating therethrough. The copper terminal 30 penetrates through the ceramic cylinder 30A. An annular cutout 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
At A-1, an annular metal seal ring 33A whose both ends are bent in the same direction and whose longitudinal section is substantially U-shaped is fitted. The metal seal ring 33A is welded to the lower terminal plate 31, and the ceramic cylinder 3
OA is brazed. By fixing to the lower terminal plate 31 by welding and brazing the metal seal ring 33A, it is possible to completely seal the through hole 31A and the ceramic cylindrical body 30A in the lower terminal 31.

As shown in FIG. 2, the lower flange portion 25A is formed at the lower end 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 (FIG. 2). Are fixed to the lower terminal plate 31. The spacer 32 is attached to the inner side and the bottom 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 cylindrical body 30A made of ceramic passes through the through hole 32A.

In other words, the cylindrical body 30A made of ceramics
Is firmly fixed by penetrating through 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 protrudes from the opening of the tip of the ceramic cylinder 30A protruding from the through hole 32A of the spacer 32.
Are connected to a rod-shaped conductor 41 which is a conductive member.
Ceramic cylindrical body 30A protruding from through-hole 32A
An annular metal seal ring 33B whose both ends are bent in opposite directions to form a cup-shaped cross section is attached to the tip end of the terminal with the copper terminal 30 fitted in the center opening thereof. Then, the metal seal ring 33B is secured by brazing to ceramic tubular body 30A, also,
It is fixed brazed to a copper terminal 30. By brazing of the metal seal ring 33B, ceramic tubular body 30
The gap between A and the copper terminal 30 can be completely sealed.

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

As shown in FIG. 4, the motor side seal portion 28
A is a terminal 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 ceramic, and a lower terminal plate 131. There is provided a first metal seal ring 133A for sealing the ceramic cylinder 130A, and a second metal seal ring 133B for sealing the ceramic cylinder 130A and the copper terminal 30.

The first metal seal ring 133A
And second metal seal ring 133B are made of, for example, Ni
-Co-Fe based alloy.

As shown in FIG. 4, the through-hole 131A provided in the lower terminal plate 131 is
A first circular recess 131A-1 opening on the surface of the lower terminal plate 131 on the ninth side;
Established on the bottom of A-1, and the lower terminal plate 13
The casing 19 has a cylindrical through-hole 131 </ b> A- 2 penetrating the surface on the side opposite to the casing 19. First circular recess 131A-
1 and the cylindrical through-hole 131A-2 have a relationship sharing the same central axis. The annular recess 131A-3 is provided in the casing 1
It is formed on the surface of the terminal plate 131 on the ninth side so as to share the same center as the first circular concave portion 131A-1. The inner diameter of the annular recess 131A-3 is the first circular recess 13
1A-1, the annular concave portion 131A-3 and the first circular concave portion 131A-1 are larger than the outer diameter of the terminal plate 1A.
31 are spaced apart from each other with a small distance via an annular protrusion 131A-4 that forms a part of the base 31.

An annular projection 30-1 having a diameter larger than the diameter 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 electric coupling means 29A.

The ceramic cylinder 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.

The copper terminal 30 is inserted into the through hole 131A in a state where the copper terminal 30 is inserted through the ceramic cylinder 130A, and the outer peripheral portion 130A-1 of the ceramic cylinder 130A is formed. the outer surface is joined by brazing to the inner surface of the first metal seal ring 133A, a seal portion. This seal portion is a through hole 131
A is inserted until the upper end of the large diameter outer peripheral portion 130A-1 reaches the bottom of the first circular concave portion 131A-1 in the lower terminal plate 131. First circular recess 131A-
The inner diameter of 1 is determined so that a seal portion formed by a ceramic cylindrical body 130A and a first metal seal ring 133A is 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 formed in the first circular recess 13.
When correctly inserted into 1A-1, the outer end in the axial direction of the first metal seal ring 133A is flush with the annular end surface of the annular protrusion 131A-4 of the lower terminal plate 131. The axially outer end of the first metal seal ring 133A and the annular projecting portion 131A-4 is secured by brazing.

As described above, the ceramic cylinder 1
30A and the first metal seal ring 133A is brazed, the first metal sealing ring 133A and the lower terminal 131 is welded, whereby a ceramic cylindrical body 130A and the first metal sealing ring 133A and the lower terminal plate 31 Are completely integrated and the seal is complete.

On the other hand, the rear end of the ceramic cylinder 130A into which the terminal 30 is inserted is in contact with the edge of the annular projection 30-1 of the terminal 30. The annular second metal seal ring 133B is disposed so as to cover the joint between the annular protrusion 30-1 and the bottom end of the ceramic cylinder 130A. A second metal seal ring 133B and the annular protrusion 30-1 is sealed bonded by brazing, the second metal seal rings 133B and ceramic tubular body 1
30A and is bonded sealing by brazing. Therefore,
The ceramic cylinder 130A and the copper terminal 30 are completely and integrally sealed.

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

The power-supply-side seal portion 27 is a power-supply-side terminal, a terminal 36 made of a metal having corrosion resistance to a corrosive liquid such as liquefied ammonia, for example, a stainless steel
When a connection member made of a socket 36A and a nut 36B, a first gasket 26A and a second gasket 26B made of non-conductive material such as Teflon, non-conductive material such as Teflon (registered trademark) of the cylindrical body and 26 C Having.

[0050] The socket 36A has one end to the flange portion 36 A
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 connected to the shaft 36A-1 of the socket 36A.
Is an annular plate having substantially the same inner diameter as the outer diameter of the plate. Moreover, Teflon cylindrical body 26C is in the upper terminal plate 37 which is the upper base made of metal such as stainless a corrosion resistance which has substantially the same inner diameter as the outer diameter of the shaft 36A-1 of the socket 36A The outer diameter is substantially the same as the inner diameter of the provided through hole 37A (the second through hole).

The terminal 36 made of stainless steel is
A is inserted. The second gasket 26B includes a shaft 36
It is inserted into A-1 and mounted on the flange 36A-2.
The cylindrical body 26C is arranged on the outer periphery of the shaft 36A-1 to form an assembly of a socket and a gasket. The assembly of this socket and gasket is a shaft 36A-1
Is inserted into the through-hole 37A of the upper terminal plate 37 until the upper end thereof protrudes from the upper surface of the upper terminal plate 37 and the second gasket 26B is in close contact with the lower surface of the upper terminal plate 37. Then, the first gasket 26A and the washer 26D are fitted into a portion of the shaft 36A-1 that protrudes upward. Then nut 3
6B is screwed to the outer periphery of the upper protruding portion of the shaft 36A-1 of the socket 36A, and the first and second gaskets 26
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. Thereby, the upper terminal plate 37
Of the through hole 37A is completed.

The upper terminal plate 37 is provided for the cylindrical body 2.
5 is mounted on the upper end thereof with a gasket 26 interposed therebetween.
The upper terminal plate 37 is connected to an upper flange 25B formed at the upper end of the tubular body 25 by bolts 39 (only one is shown in the figure). The upper terminal 36
It is protected by a cover member 38 attached to the upper terminal plate 37 with bolts (only one is shown in the figure).

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

Further, the inside of the cylindrical body 25 has a gas introducing portion 42 provided on the side wall of the cylindrical body 25. The gas introduction unit 42 is connected to a gas introduction pipe (not shown) provided with a pressure gauge (not shown) on the way, and an inert gas such as N ₂ gas is introduced into the cylindrical body 25. It has become. In addition, instead of introducing the inert gas, an insulating material such as a silicon resin may be filled from the gas introducing portion 42. In short, if it is possible to exclude air containing moisture or moisture from the inside of the cylindrical body 25, an inert gas ("insulating gas ") is used.
S ". ) Or an insulating material.

On the side wall of the cylindrical body 25, there is provided a gas discharge section 43 for connecting an open / close valve (not shown), so that the N ₂ gas introduced from the gas introduction section 42 can be discharged. I have.

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

The connection terminal 9 of the canned motor pump 1
According to this, the housing is formed of a non-corrosive metal such as a lower terminal plate 31 made of stainless steel, a non-corrosive metal such as an upper terminal plate 37 made of stainless steel, and a non-corrosive metal such as a cylindrical body 25 made of stainless steel. Therefore, they do not corrode even if they come into contact with corrosive liquid such as liquefied ammonia flowing in the column pipe 2.

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

Further, in a case where N ₂ gas is introduced into the cylindrical body 25 from a gas introduction portion 42 provided on the side wall of the cylindrical body 25 to perform N ₂ gas purging, The leakage phenomenon caused by the dew condensation phenomenon that occurs when air exists in the body 25 can be prevented.
Further, by keeping the purged N ₂ gas at a pressure equal to or higher than the internal pressure of the column pipe, liquid leakage from the power supply side seal portion 27 can be suppressed.

Further, by monitoring the pressure inside the cylindrical body 25 with a pressure gauge connected to the N ₂ gas introduction pipe, the leakage of the liquid can be detected, and the canned motor pump disposed in the liquid can be detected. 1 can be improved.

The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the invention.

[0063]

According to the present invention described in detail above, since the above-described structure is adopted, leakage of corrosive liquid can be eliminated by the double seal structure, and an insulating gas or an insulating material can be applied to this connection terminal. And a connection terminal of the motor pump which can ensure high reliability can be provided.

[Brief description of the drawings]

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

FIG. 2 is an enlarged vertical sectional view showing a connection terminal structure of the canned motor pump in the present embodiment.

FIG. 3 is an enlarged partial longitudinal sectional view showing a state where a motor-side terminal is attached to a housing in a connection terminal structure of the canned motor pump according to the present embodiment.

FIG. 4 is a partially enlarged longitudinal sectional view showing another example of a state in which a motor-side terminal is attached to a housing at a connection terminal of the canned motor pump of the present embodiment.

FIG. 5 is a partially enlarged longitudinal sectional view showing a state in which a power supply side terminal is attached to a housing in a hermetic terminal of the canned motor pump according to 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 sectional view showing a conventional hermetic terminal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Canned motor pump, 2 ... Column pipe, 3 ... Head plate, 4 ... Lift cable, 5
... hanging bracket, 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, 15 ...
And drive shaft, 16 ... B over data, 17 ... winding, 18 ... stearyl over <br/> data, 19 ... connection terminal base, 20 ... inducer, 2
DESCRIPTION OF SYMBOLS 1 ... Impeller, 22 ... Diffuser, 23 ... Balance mechanism part, 24 ... Liquid discharge port, 25 ... Cylindrical body, 25A *
..Lower flange portion, 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 Projecting portion, 30A: ceramic cylinder, 31: lower terminal plate, 31A: through hole, 31A-1: annular cutout portion, 32: spacer, 32A: Through holes, 33A, 33B: metal seal ring, 34: bolt, 36: stainless steel terminal, 36A: socket, 36B: nut, 36A-1: hollow shaft, 36
A-2: flange , 36A-3: screw, 37: upper terminal plate, 37A: through hole, 38: cover member, 39 ...
-Bolt, 41 ... conductor, 42 ... introduction part, 43 ... gas discharge part, 130A ... ceramic cylinder, 131 ... lower terminal plate, 131A ... through hole, 131A -1: first circular concave portion, 131A-2: cylindrical through hole, 131A-3: annular concave portion, 131A-4: annular projecting portion, 133A: first metal seal ring 133B... A second metal seal ring.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F04D 13/08 F04D 7/02 F04D 29/00 F04D 29/02 H02G 15/08

Claims (7)

(57) [Claims] A first conductive cable provided in a casing of a motor pump disposed in a storage tank for liquefied ammonia or a liquid similar thereto and supplying a current to a motor in the motor pump; A connection terminal for connecting the second conductive cable to be supplied; a lower base arranged in the casing; a tubular body having a first open end hermetically closed by the lower base;
A housing having an upper closing member for hermetically closing a second open end of the tubular body; and a first conductive cable for supplying a current to a motor in a motor pump; The motor-side terminal is held in an airtight and insulated state in a first through-hole provided in the first through-hole, and is held in a gas-tight and insulated state through a gasket in a second through-hole provided in the upper closing member. However, a power supply-side terminal made of a metal that is resistant to corrosion with respect to liquefied ammonia or a liquid similar thereto and provided in the housing, provided at the end of a second conductive cable that supplies current from a remote power supply. And a conductive member for connecting the motor-side terminal and the power-supply-side terminal. 2. The motor pump connection terminal structure according to claim 1, wherein the power source terminal of the corrosion-resistant metal is made of aluminum or stainless steel. 3. An electrically insulating tubular body is inserted through the through-hole provided in the lower base and is air-tightly coupled to the through-hole with a first metal sealing member. The motor pump connection terminal structure according to claim 1, wherein the motor pump connection terminal structure is inserted through the electrically insulating tubular body and hermetically sealed with 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. coupled hermetically by brazing to the tubular body while being coupled hermetically by welding, the second metal sealing ring, and the motor-side terminals together is hermetically joined by brazing to the tubular body connecting terminal structure of the motor pump according to claim 3 comprising joined hermetically by brazing. 5. The connection terminal structure for a motor pump according to claim 1, wherein a 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 a nitrogen gas and a rare gas or a mixed gas thereof. 7. The connection terminal of the motor pump according to claim 1, wherein the housing is filled with an insulating material.
Structure .