JP2015179580A - Bushing and feed through - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge tolerance of relative displacement due to difference of a linear expansion coefficient between an insulation pipe and conductor.SOLUTION: A conductor plug portion 231 is configured so that, a right side part of the conductor plug portion 231 is passed in a hollow part of a female-shaped insulation pipe 221, and is sealed tightly to the female-shaped insulation pipe 221 on a position of a left side opening. A conduction socket portion 232 is configured so that a left side part of the conduction socket portion 232 is passed in a hollow part of a male-shaped insulation pipe 222, and is sealed tightly to the male-shaped insulation pipe 222 on a right side opening. The left side of the male-shaped insulation pipe 222 is inserted into the hollow part of the female-shaped insulation pipe 221 while having play, so that the male-shaped insulation pipe and female-shaped insulation pipe do not contact with each other and a slight gap is formed between them. Then the right side of the conductor plug portion 231 is inserted into the socket part of the conductor socket part 232 loosely, and the conductor plug part 231 and conductor socket part 232 are electrically coupled via a multi-ram band 26.

Description

  The present invention relates to a bushing and a feedthrough used for supplying power to a liquefied gas tank.

  As a technology related to bushing and feedthrough used for power supply to a liquefied gas tank, feedthrough used for power supply to a submerged pump installed in the liquefied gas tank for pumping liquefied gas is known. (For example, Patent Document 1).

  As shown in the cross-sectional view of FIG. 7, the feedthrough is composed of a disk-shaped terminal header base 71 and a bushing 72 inserted through a through hole provided in the terminal header base 71. The bushing 72 is a terminal header. At both ends of the through hole of the base 71 in the axial direction, the terminal header base 71 is hermetically fixed with a sealing member 73 interposed.

  The bushing 72 includes a hollow tubular insulating tube 721 made of an insulating material such as ceramics, a conductor 722 inserted through a hollow portion of the insulating tube, and terminals 723 connected to both ends of the conductor.

  In addition, at one end of the hollow portion of the insulating tube 721, the space between the insulating tube 721 and the conductor is hermetically sealed with a first sealing fitting 724. In addition, at the other end of the hollow portion of the insulating tube 721, between the insulating tube 721 and the conductor 722, a second sealing member 725 hermetically sealed to the insulating tube 721 and a second sealing member 725 are connected. Is sealed hermetically by an S-shaped bellow 726 that is welded to the other side and hermetically sealed to the conductor 722.

Here, the S-type bellows 726 has flexibility and absorbs a difference in linear expansion coefficient between the insulating tube 721 and the conductor 722 by bending, and relieves thermal stress in each part.
Further, the feed-through terminal header base 71 as described above is installed so as to airtightly block the opening provided at the position outside the liquefied gas tank of the liquefied gas pumping pipe extended to the outside of the liquefied gas tank. Electric power is supplied to the submerged pump in the liquefied gas tank from outside the liquefied gas tank via 72.

JP-A-10-116529

According to the feedthrough described above, the relative displacement between the insulating tube 721 of the bushing 72 and the conductor 722 due to the difference in linear expansion coefficient is absorbed by the deflection of the S-shaped bellows 726.
However, the amount of displacement between the insulating tube 721 and the conductor 722 that can be absorbed by the S-type bellows 726 is relatively small, and when the temperature of the absorbed liquefied gas becomes extremely low, the S-type bellows 726 and the second sealing fitting 725 There is a possibility that the airtightness between the insulating tube 721 and the conductor 722 cannot be maintained due to, for example, the bonding of the second sealing fitting 725 and the insulating tube 721 coming off.

  Therefore, an object of the present invention is to provide a bushing and a feedthrough that can allow a relative displacement due to a difference in linear expansion coefficient between an insulating tube of a bushing and a conductor to be larger.

  In order to achieve the above object, the present invention is formed of an insulating material having a hollow portion penetrating in the axial direction as a bushing fixed to the base member in a form penetrating a bushing mounting hole provided in the base member. A bushing comprising a hollow tubular insulating part and a conductor part inserted through the hollow part of the insulating part is provided. However, the conductor portion includes a first conductor portion hermetically sealed to the insulating portion at a first end that is one end of the insulating portion, and a second end that is the other end of the insulating portion to the insulating portion. A second conductor portion hermetically sealed, and the end portion on the second end side of the first conductor portion and the end portion on the first end side of the second conductor portion are the insulating portion. In the hollow portion of the insulating portion, the first conductor portion and the second conductor portion are electrically connected in a form that is relatively displaceable in the axial direction. .

  More specifically, in this bushing, the second conductor portion has a hole portion having an opening opened on the first end side in the hollow portion of the insulating portion, and The portion on the second end side of one conductor portion may be configured to fit in the hole portion of the second conductor portion so as to be displaceable in the axial direction within the hollow portion of the insulating portion.

  According to such a bushing, the conductor portion is divided into a first conductor portion and a second conductor portion, and the first conductor portion and the second conductor portion are electrically displaced in a form that can be relatively displaced in the axial direction. Therefore, the relative displacement between the insulating part and the conductor part caused by the difference in linear expansion coefficient between the insulating part and the conductor part is reduced between the first conductor part and the second conductor part. Absorption is performed by relative displacement, and stress can be prevented from occurring in each part.

  In the above bushing, the insulating portion is composed of a first insulating tube having a hollow portion penetrating in the axial direction and a second insulating tube having a hollow portion penetrating in the axial direction, and the second insulating tube The first end side portion of the first insulating tube is configured to be loosely inserted into the second end side portion of the hollow portion of the first insulating tube so that a gap is generated between the first insulation portions. Also good.

  By doing so, the dimensional change accompanying the temperature change of the insulating part is absorbed as expansion and contraction of the gap between the first insulating pipe and the second insulating pipe, and the stress applied to the connecting part between the bushing and the terminal header base Can be reduced. In addition, since the electrical creepage distance between the conductor portion and the outside of the bushing is equal to or longer than the length of the second insulation tube that is loosely inserted into the hollow portion of the first insulation tube, the electrical creepage distance is ensured to be large. Will be able to.

  In addition, since the atmospheric pressure or the like in the insulating portion can be detected using the gap between the first insulating tube and the second insulating tube that appears on the outer surface of the bushing, it is possible to detect the hermetic breakdown of the bushing. It becomes like this.

  Here, the present invention also provides a feedthrough having the above bushing and the base member. However, in the feedthrough, the insulating portion is hermetically sealed to the base member at positions at both axial ends of the bushing mounting hole of the base member.

  In the case where the first insulating pipe and the second insulating pipe constitute an insulating portion, in the feedthrough, the first insulating pipe is connected to one end in the axial direction of the bushing mounting hole of the base member. The base member is hermetically sealed to the base member at a position, and the second insulating tube is hermetically sealed to the base member at the other end in the axial direction of the bushing mounting hole of the base member. In addition, a detection hole that extends from an opening provided on the surface of the base member to a gap between the first insulating tube and the second insulating tube may be provided.

  As described above, according to the present invention, it is possible to provide a bushing and a feedthrough that can tolerate a relative displacement due to a difference in linear expansion coefficient between the bushing insulating tube and the conductor.

It is a figure which shows the example of application of the feedthrough which concerns on embodiment of this invention. It is a figure which shows the external appearance of the feedthrough which concerns on embodiment of this invention. It is a figure which shows the structure of the terminal header base which concerns on embodiment of this invention. It is a figure which shows the structure of the bushing which concerns on embodiment of this invention. It is a figure which shows the structure of the feedthrough which concerns on embodiment of this invention. It is a figure which shows the other example of the terminal header base which concerns on embodiment of this invention. It is a figure which shows the conventional feedthrough.

Hereinafter, embodiments of the present invention will be described.
First, an example in which the feedthrough according to the present embodiment is applied to supply power to a submerged pump in a liquefied gas tank is shown in FIG.
As shown in the figure, a tank 100 that stores low-temperature liquefied gas such as LNG, LPG, or liquid hydrogen is provided with a liquefied gas pumping pipe 101 that penetrates the upper wall of the tank 100 in an airtight manner.
The lower end of the liquefied gas pumping pipe 101 is fixed to the floor of the tank 100 so that the lower end is located slightly above the floor of the tank 100. A submerged pump 102 is arranged.

  Further, the opening at the upper end of the liquefied gas pumping pipe 101 arranged outside the tank 100 is hermetically sealed by the feedthrough 10, and power is supplied from the power source 103 to the submerged pump 102 via the feedthrough 10. Supplied.

A discharge path 104 is connected to the vicinity of the upper portion of the liquefied gas pumping pipe 101, and the liquefied gas pumped by the submerged pump 102 is discharged to the discharge path 104.
Next, the feedthrough 10 according to the present embodiment will be described.
FIG. 2 shows the appearance of the feedthrough 10.
As shown in the drawing, the feedthrough 10 is composed of a disk-shaped terminal header base 1 and three bushings 2 respectively inserted into three bushing insertion holes 11 provided in the terminal header base 1. Are airtightly fixed to the terminal header base 1 at both axial ends of the bushing insertion holes 11 of the terminal header base 1. Here, the three bushings 2 respectively relay the three-phase power feeding lines feeding the submerged pump 102 inside and outside the liquefied gas pumping pipe 101.

Next, FIG. 3 shows the structure of the terminal header base 1 of the feedthrough 10.
3, FIG. 3a is a top view of the terminal header base 1, FIG. 3b1 is a side view of the terminal header base 1, FIG. 3b2 is a cross section of the terminal header base 1 along the cutting line AA in FIG. The lower surface of the terminal header base 1 is represented.

As shown in the figure, the terminal header base 1 is a substantially disk-shaped member, and is provided with three bushing insertion holes 11 at the center and a plurality of bolt holes 12 at the outer edge. The base 1 has a connecting hole 13 that connects the three bushing insertion holes 11 at the position in the axial center of the bushing insertion hole 11, and a position between the axial ends of one bushing insertion hole 11 from the side surface of the terminal header base 1. A detection hole 14 is provided so as to penetrate to the end.

An annular groove 15 for fixing the bushing is formed around the bushing insertion hole 11 on the upper and lower surfaces of the terminal header base 1.
Next, FIG. 4 shows the configuration of the bushing 2 of the feedthrough 10.
4A and 4B, the appearance of the bushing 2 is shown in FIG. 4, and FIG. FIG. 4b shows the bushing 2 rotated 90 degrees around the axis of the bushing 2 from the state of FIG. 4a.

Hereinafter, for the sake of convenience, the structure of the bushing 2 will be described with the left-right direction of FIGS.
As shown in the figure, the bushing 2 includes an insulating portion 22 having a cylindrical shape as a whole, a conductor portion 23 that penetrates a hollow portion of the insulating tube unit, a first sealing member 241, a second sealing member 242, The first terminal 251, the second terminal 252, and the multilam band 26 are configured.

  The first terminal 251 and the second terminal 252 are connected to both ends of the conductor portion 23. In addition, the gap between the hollow portion of the insulating portion 22 and the conductor portion 23 is hermetically sealed by the first sealing member 241 and the second sealing member 242 at both ends of the conductor portion 23. Yes.

  Here, the insulating part 22 is composed of two separated members, a female insulating tube 221 formed of an insulating material such as ceramics and a male insulating tube 222 formed of an insulating material such as ceramics. . The conductor portion 23 is composed of two separated members, a conductor plug portion 231 formed of a conductive material such as copper and a conductor socket portion 232 formed of a conductive material such as copper.

  More specifically, the female insulating tube 221 has a hollow tube shape, and the conductor plug portion 231 has a cylindrical shape. The first terminal 251 is connected to the left side of the conductor plug portion 231.

  In addition, the conductor plug portion 231 has a female-shaped insulating portion in a state where the right portion of the conductive plug portion 231 is passed through the hollow portion of the female-shaped insulating tube 221 so that the right-side portion is surrounded by the female-shaped insulating tube 221. At the position of the opening on the left side of the tube 221, the female sealing tube 221 is hermetically sealed by the first sealing member 241.

  On the other hand, the male insulating tube 222 has a hollow tube shape, and the conductor socket portion 232 is provided with a socket portion which is an axial hole having an opening on the left side. The second terminal 252 is connected to the right side of the conductor socket part 232. A multiram band 26 is inserted into the socket portion of the conductor socket portion 232. Here, the outer diameter of the left portion of the male insulating tube 222 is set smaller than the inner diameter of the hollow portion of the right portion of the female insulating tube 221.

  In addition, the conductor socket part 232 has a male shape in a state where the left part of the conductor socket part 232 is passed through the hollow part of the male insulating pipe 222 so that the left part is surrounded by the male insulating pipe 222. At the position of the opening on the right side of the insulating tube 222, the male insulating tube 222 is hermetically sealed by the second sealing member 242.

  Then, the left side of the male insulating tube 222 is loosened in the hollow portion of the female insulating tube 221 so that the male insulating tube 222 and the female insulating tube 221 are not in contact with each other and a slight gap is formed between them. The female-shaped insulating tube 221 and the male-shaped insulating tube 222 are fixed to the terminal header base 1 so that the right side of the conductor plug portion 231 is inserted into the socket portion of the conductor socket portion 232. The Details of this fixing will be described later.

  Here, in the state where the right side of the conductor plug portion 231 is inserted into the socket portion of the conductor socket portion 232 in this way, the conductor plug portion 231 is connected to the conductor socket via the multiram band 26 in the socket portion of the conductor socket portion 232. The unit 232 is electrically connected. The conductor plug portion 231 is slidable in the axial direction with respect to the multi-ram band 26.

  Here, as shown in FIG. 4 c, the internal space of the female insulating tube 221 and the male insulating tube 222 passes through a passage formed by a gap between the female insulating tube 221 and the male insulating tube 222. Thus, the opening 27 that appears at the axial center of the side surface of the bushing 2 is connected to the external space.

  The electrical creepage distance between the conductor plug portion 231 and the conductor socket portion 232 and the outside of the bushing 2 is such that the gap between the male insulation tube 222 and the female insulation tube 221 is the female insulation of the male insulation tube 222. Since the length of the path to the opening 27 that goes around the portion inserted into the tube 221 is, the electrical creepage distance is sufficiently larger than the distance from the conductor portion 23 to the outer peripheral surface of the insulating portion 22. Yes.

  4d1 shows the external appearance of the multi-ram band 26 as viewed from the axial direction of the bushing 2, and FIG. 4d2 shows the external appearance of the multi-ram band 26 as viewed from the radial direction of the bushing 2. As shown in FIG. It is a substantially drum-shaped member that is formed of a conductor such as a concave portion in the center direction in the axial direction of the side surface, and presses both the conductor plug portion 231 and the conductor socket portion 232 with elasticity, Connect electrically. However, the multi-ram band 26 may have another shape, or an electrical contact other than the multi-ram band 26 may be used to electrically slide the conductor plug portion 231 and the conductor socket portion 232. You may connect.

Next, details of the feedthrough 10 constituted by the terminal header base 1 and the bushing 2 as described above will be described.
FIG. 5 a shows a cross section of the feedthrough 10, and FIG. 5 b shows an enlarged view of a cross section around the portion where the bushing 2 of the feedthrough 10 is attached.
As shown in the figure, each bushing 2 has a C-shaped bellows 28 brazed to the outer peripheral surfaces of a male-shaped insulating tube 222 and a female-shaped insulating tube 221 on the bushing 2, and the bushing 2 is connected to the first terminal 251. By inserting the C-shaped bellows 28 in an annular groove 15 formed on the upper and lower surfaces of the terminal header base 1 by welding or the like, respectively, so that the side is inside the tank. The terminal header base 1 is fixed. The diameter of the bushing insertion hole 11 is formed so that the inside of the tank is somewhat larger. In order to improve the mechanical strength, the outer periphery of the male insulating tube 222 is formed in a step formed by the difference in the diameter. The bushing 2 is attached to the terminal header base 1 in a form in which a flange-shaped portion provided on the side is in contact with the first terminal 251 side.

  Here, in the state where the bushing 2 is fixed to the terminal header base 1 in this way, the space inside the female-shaped insulating tube 221 and the male-shaped insulating tube 222 of each bushing 2 communicates with the terminal header base 1 through the opening 27. It communicates with the hole 13. The space inside the female insulating tube 221 and the male insulating tube 222 of one bushing 2 communicates with the detection hole 14 of the terminal header base 1. Therefore, the space inside the female insulating tube 221 and the male insulating tube 222 of each bushing 2 communicates with the detection hole 14 of the terminal header base 1.

  Therefore, the air pressure destruction of the space inside the female insulating tube 221 and the male insulating tube 222 of each bushing 2 is monitored with a monitoring device connected to the opening of the detection hole 14 on the side surface of the terminal header base 1. It can be detected rather than doing.

  Moreover, in such a feedthrough 10, between the insulating part 22 of the female-shaped insulating tube 221 and the male-shaped insulating tube 222 of each bushing 2, and the conductor member of the conductor socket part 232 and the conductor plug part 231, When a relative displacement occurs due to the difference in linear expansion coefficient, the conductor plug portion 231 maintains electrical connection to the multi-ram band 26 in the socket portion of the conductor socket portion 232 as indicated by reference numeral 500 in FIG. By sliding, the displacement is absorbed so that stress does not occur in each part such as the sealing part of the first sealing member 241 and the second sealing member 242. Here, the distance that the conductor plug portion 231 can slide within the socket portion of the conductor socket portion 232 can be set to be relatively large by appropriately setting the shape and arrangement of the conductor plug portion 231 and the conductor socket portion 232. it can. Therefore, the relative displacement can be more greatly tolerated by the difference in coefficient of linear expansion between the insulating portion 22 of the bushing 2 and the conductor member.

  Further, the dimensional change accompanying the temperature change of the insulating portion 22 is also absorbed as the expansion and contraction of the gap between the female insulating tube 221 and the male insulating tube 222, and is caused by the C-shaped bellows 28 between the bushing 2 and the terminal header base 1. Stress applied to the connecting portion is also reduced.

  As shown in FIG. 5a, the lower surface of the terminal header base 1 is formed at the upper end of the liquefied gas pumping tube 101 of the terminal header base 1 by using bolt holes 12 provided at the outer edge of the terminal header base 1. It is fastened with a bolt to a flange provided in the.

In addition, a wiring cover tube 106 is connected to the upper surface of the terminal header base 1 by using bolt holes 12 provided in an outer edge portion of the terminal header base 1.
In addition, the first terminal 251 and the second terminal 252 of the bushing 2 are hermetically sealed with a predetermined sealing material in a state where an insulated wire serving as a feeder line is connected.
The embodiment of the present invention has been described above.
In the above embodiment, the terminal header base 1 having a substantially disk shape is used as the terminal header base 1, but the shape of the terminal header base 1 may be a shape other than the substantially disk shape.

That is, for example, a schematic shape as shown in FIG. 6a, in which two upper and lower flanges are vertically connected by a hollow cylindrical portion, may be used.
Here, in FIG. 6a, FIG. 6a1 shows the top surface of the terminal header base 1, FIG. 6a2 shows the side surface of the terminal header base 1, and FIG. 6a3 shows the cross section of the terminal header base 1 along the cutting line AA in FIG. FIG. 6 a 4 shows the lower surface of the terminal header base 1.

  As illustrated, the terminal header base 1 includes an upper flange portion 601, a lower flange portion 602, and a hollow cylindrical portion 603 that connects the upper flange portion 601 and the lower flange portion 602 up and down. The upper flange portion 601 has the same configuration as that of the disk-shaped terminal header base 1 shown in FIG. 3, and the lower flange portion 602 has an annular shape in which the bolt hole 12 is provided at the outer edge portion. ing.

  For example, as shown in FIG. 6 b, the lower surface of the lower flange portion 602 of the terminal header base 1 liquefies the terminal header base 1 using the bolt holes 12 provided in the outer edge portion of the terminal header base 1. The bolt is fastened to a flange provided at the upper end of the gas pumping pipe 101 with a bolt.

  Further, a wiring cover tube 106 is connected to the upper surface of the upper flange portion of the terminal header base 1 by using a bolt hole 12 provided in an outer edge portion of the upper flange portion of the terminal header base 1.

In addition, the first terminal 251 and the second terminal 252 of the bushing 2 are hermetically sealed with a predetermined sealing material 302 in a state where an insulated wire 301 serving as a feeder line is connected.
Here, the feedthrough 10 using the terminal header base 1 having two upper and lower flanges shown in FIG. 6a is applied to a liquefied gas pumping pipe 101 bent near the upper end as shown in FIG. 6b. Is preferred. By using such a terminal header base 1, a large bending radius in the vicinity of the first terminal 251 of the feeder line can be secured.

  In the above, the feedthrough 10 used for supplying power to the submerged pump 102 of the liquefied gas tank has been described as an example. However, the bushing 2 and the feedthrough 10 according to the present embodiment are inside and outside the liquefied gas tank and other sealed containers. Can be used to establish any electrical connection.

  DESCRIPTION OF SYMBOLS 1 ... Terminal header base, 2 ... Bushing, 10 ... Feed through, 11 ... Bushing insertion hole, 12 ... Bolt hole, 13 ... Communication hole, 14 ... Detection hole, 15 ... Groove, 22 ... Insulation part, 23 ... Conductor part, 26 ... Multi-ram band, 28 ... C-type bellows, 100 ... Tank, 101 ... Pipe for pumping liquefied gas, 102 ... Submerged pump, 103 ... Power supply, 104 ... Discharge path, 105 ... Tube, 221 ... Female-shaped insulation pipe , 222 ... male-shaped insulating tube, 231 ... conductor plug part, 232 ... conductor socket part, 241 ... first sealing member, 242 ... second sealing member, 251 ... first terminal, 252 ... second terminal, 301 ... Insulated wires, 302... Sealing material, 601... Upper flange portion, 602... Lower flange portion, 603.

Claims (5)

A bushing fixed to the base member in a form penetrating a bushing mounting hole provided in the base member,
A hollow tubular insulating portion formed of an insulating material having a hollow portion penetrating in the axial direction;
A conductor portion inserted through the hollow portion of the insulating portion;
The conductor portion is hermetically sealed to the insulating portion at a first end that is one end of the insulating portion and hermetically sealed to the insulating portion at a first end, and at a second end that is the other end of the insulating portion. A second conductor portion sealed,
The end portion on the second end side of the first conductor portion and the end portion on the first end side of the second conductor portion are in the hollow portion of the insulating portion,
In the hollow part of the said insulation part, the said 1st conductor part and the said 2nd conductor part are electrically connected in the form which can be displaced relatively to an axial direction, The bushing characterized by the above-mentioned. The bushing according to claim 1,
The second conductor portion has a hole portion having an opening opened on the first end side in a hollow portion of the insulating portion, and the portion on the second end side of the first conductor portion is the insulating portion. In the hollow portion, the bushing is fitted in the hole portion of the second conductor portion so as to be axially displaceable. The bushing according to claim 1 or 2,
The insulating portion includes a first insulating tube having a hollow portion penetrating in the axial direction, and a second insulating tube having a hollow portion penetrating in the axial direction.
The portion on the first end side of the second insulating tube is loosely inserted into the second end side portion of the hollow portion of the first insulating tube in such a manner that a gap is generated between the first insulation. Bushing characterized by being. A feedthrough comprising the bushing according to claim 1 and the base member,
The feedthrough according to claim 1, wherein the insulating portion is hermetically sealed to the base member at positions at both axial ends of the bushing mounting hole of the base member. A feedthrough comprising the bushing according to claim 3 and the base member,
The first insulating tube is hermetically sealed to the base member at one axial end of the bushing mounting hole of the base member, and the second insulating tube is an axis of the bushing mounting hole of the base member. Hermetically sealed to the base member at the other end of the direction,
The feedthrough characterized in that the base member has a detection hole that leads from an opening provided on the surface of the base member to a gap between the first insulating tube and the second insulating tube.