US1754833A - High-voltage structure - Google Patents

Description

April 15, 1930. J. E. MATEER HIGH VOLTAGE STRUCTURE Filed May 19, 1927 2 Sheets-Sheet -1 INVENTOR Jesse B. Mateer WITNESSES: #704,001?

ATTOR N EY April 15, 1930. 7 MATEER 1,754,833

7 HIGH VOLTAGE STRUCTURE Filed May 19, 1927 Q 2 Sheets-Sheet 2 in breaker WITNIESSES: I INVENTOR M Z Jesse E. Maker ATTORNEY Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE JESSE E. .HATEER, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA HIGH-VOLTAGE STRUCTURE Application filed May 19, 1927. Serial No. 192,589.

My invention relates to high-voltage structures and particularly to bushing structures and the associated parts of oil filled circuit interrupters, or similar devices, with which the bushings are associated.

One object of my invention is to provide a structure of the above-indicated character that shall permit the bushing, as one unit, and a main casing or tank, a well structure for local disposition about a portion of the bushing in the tank, and other parts, as another unit, to be adjusted relatively at, and shipped separately from, the factory and assembled at the service station, without further adjustment.

Another object of my invention is to provide a bushing structure, for a high-voltage, oil-filled circuit interrupter, in which a body of oil, immediately adjacent to the bushing, shall be maintained free of carbon and metallic particles which are given off to the main oil body when the interrupter operates under heavy loads.

Another object of my invention is to provide a well structure, forlocal disposition about the inner end of a circuit-interrupter or similar bushing, that shall be adapted for insertion through the bushing opening in the interrupter tank and that shall permit the mounting of the bushing and of the well structure from the outside of the tank.

Another object of my invention is to, provide a well structure, for the reception of a bushing, in which a flexible conductor, for threading through the bushing, shall be mounted for shipping with the well, separate- 1y from the bushing, and so fixed or adjusted at the factory as to require no further adjusting and to preventits loosening by the effects of current therein.

Another object of my invention is to provide an effectively sealed bushing structure that shall embody means for adjusting a conductor or contact member, at one end thereof, relative to a cooperating conductor adjacent to said end, as by bodily adjusting the bushing relative to a wall or cover member with which it is associated.

Another object of my invention isto provide a bushing structure that shall so embody a condenser bushing and a surrounding well or oil contained therefor as to Withstand very high voltages and to be, in general, an improvement over bushing structures heretofore employed.

Another object of my invention is to provide a well structure, for a high-voltage bushing, that shall comprise a metal section and a relatively massive oil-immersed porcelain section having a creepage surface of relatively great area, that shall be adapted for the reception of a transformer element and that shall embody effectively sealed terminals for the transformer element.

A further object of my invention is to provide a high-voltage structure that shall be simple and durable in construction, economical to manufacture and effective in its operation.

In high-voltage structures, such as oil-filled circuit interrupters, the various parts must be exceedingly carefully designed, constructed, assembled, and adjusted because of the high-voltage stresses, the presence of oil, the formation of gases and arcs, and other features.

Care must be taken, not only from a safety standpoint, but also that the device may always be in condition, when required to operate to a maximum degree of efliciency and not be rendered ineffective from preceding operations.

Since, in oil-filled circuit interrupters, the inner ends of the terminal bushings are usually immersed in the same body of oil that surrounds the contact members, carbon and metallic particles, which are sometimes formed when the interrupter operates under heavy loads, reduce the insulating value of the oil and tend to break down the surface of the bushing therein. The inner ends of such bushings are, also, usually provided with limited or insufficient creepage surface. Also, by reason of their size, certain of these interrupters and the bushings therefor are shipped separately and assembled at the place of installation.

Since the parts must be carefully put together at the factory, considerable trouble and expense are occasioned by the delicate and again assembled.

Further, there is the .danger that the second, ,or final, assembly may not be so carefully performed as the first assembly, with I the consequent less effective operation and greater likelihood of damage.

It is my aim to reduce the above-mentioned effect of the carbon and metallic'particlesin structure of their character to employ a condenser bushing that shall be entirely free of such particles, to provide a device having materially increased creepage-surface area, and to provide a structurein which the field mounting of the bushings shall be free of delicate adjustments and thereby rendered a simple and economical operation. 4

Accordingly, in practicing my invention, I provide a well structure for local disposition about the inner end of a bushing, that functions as a barrier between the oil next to the bushing and the main body of oil in an interrupter tank. The well structure and a. flexible conductor, for threading through the bushing, are so assembled'and adjusted relative to the tank and a movable contact member therein, and the bushing is so adaptready andeconomical mounting ofthe bush 7 ing during the installation of the interrupter,

without delicate adjustment or the require- 'ment of special skilL. .The arrangement of parts is so improved as to provide amaterially increased creepage surface compared to structures heretofore employed.

I "Figure 1 of the accompanying drawings is a.view,'partially in section and partially in elevation, of a high-voltage structure embodying my invention, and

Fig. 2 is a similar view of a modified form thereof 7 Referring to Fig. 1, the device comprises, in general, a wall or cover member 2' of a tank or casing (not shown), a well structure 4, a current-transformer element 5 in the well 4, and a' condenser-bushing structure 6.

The cover member 2, preferably constructedof metal, is provided with a bushing opening 7 and can annular flange 9 is provided with an inwardly-sloping or beveled outer end edge. r w

" Therwell structure 4 comprises 'an"upp.er

or open-end metal section 12, a lower or 7 bottom insulating section 14, atop cover member 15 and a bottom structure 16. The metal section 12, preferably of relatively thin-walleduniform cylindrical shape,

comprises a laterally, outwardly-projecting upper flange -18, an inwardly-projecting lower flange 19 and a downwardly projectm lower flange 20.

The upper flange 18 embodiesa sloping under surface 22 that so cooperates the gasket 30 disposed over the top edge of thesections 12, has an opening 31, a flange 32-.

aboutthe opening 31, and an outwardly-anddownwardly extending outer-edge portion 33. Bolts 34 extend through the portion 33 and into the flange 18 for securing the well cover15 in sealed position.

The lower inwardly-projecting flange 19 provides a seat for the transformer element 5 and an end shoulder for the upper end of the insulating section 14.

The downwardly-projecting lower flange 20 is constructed to have an inner diameter substantially equal to the outer diameter of the main body portions thereof and to relatively closely embrace a portion of the upper end of the insulating section 14.

A sealing and securing medium, preferably of rubber compound, is placed between the flanges 19 and 20 and the adjacent surfaces of the section 14. The insulating section 14 is preferably of relatively thick-walled and massive p'orc'elain construction, the side wall 35 of which converges downwardly and isprovided with surface-.creepage flanges 36.

Since all of the well structure 4, beneath the flange 18. isadapted for insertion through the opening 7 in the cover 2, the top flange 36'is of smaller diameter than the opening 7 and projects only a certain distance from the main wall 3511f the section 14. However, by reason of the downwardly-converging or tapering lar or sleeve portion 39 that is secured, as by r ,a body of cement 40, around the lower end of the wall 35 and hasa bottom surface that. is preferably flush with the bottom surface of the wall 35.

A metal plate 42, disposed flatly across the bottom end of the section 14, is sealed and se cured thereto, as by a gasket 43 and screws 44, respectively.

A screw-threaded conducting stud element 46. which may be integral with or otherwise suitably secured to the plate 42, projects from the plate for the reception of a Stationary contact structure (not shown) of the interrupter and has an opening at the inside of the plate for the reception of one end of a flexible condoctor or cable 48 which extends. through the bushing 6. .The cable 48, stud, 46, and plate 42 are permanently connected to each other, as by welding, to resist the highest mechanical and electrical stresses which are ordinarily met with in service, without imparing the connection.

The current-transformer element 5, of which the cable 48 constitutes a one-turn primary Winding, comprises a laminated ring core member 50 and a secondary or low-voltstrengthening rib 75. It, also,

age winding 51 which closely conforms to the inner diameter of thesection 12 and is. supported by the flange 19.

An oil-tight, low-voltage terminal device for the transformer 5 comprises an insulating bushing 53, extending through the wall of the well section 12, a conductor 54, extendin through the bushing, washers 55 and nuts 5 for attaching adjacent conductors 58 and 59 in the circuit of the winding 51. The conductor 54 is preferably sealed in position in the bushing 53, as by being molded in the material thereof or by being surrounded by a sleeve 60 of rubber compound or other suitable material.

The condenser-bushing structure 6 comprises an inner condenser member 64, a metalcylinder supporting member 65, a collar member 67, a plurality of outer porcelain protective shells 68 and a to terminal structure 70.

The condenser mem r 64 is preferably constructed of alternate layers of metal foil and hard, molded, fibrous, insulating material, such as paper impregnated with a, phenolic condensation product, and is tapered or stepped, for considerable portions of its length, from the ends of a uniform cylindrical mid-portion 71 to its outerextremities. This construction ensures a uniform voltage gradi-' ent between the cable 48 and the cover member 2 and prevents undue concentration of electrostatic stresses.

The supporting cylinder 65 is sealed'to the mid portion 71 by a sealing medium 73 and, sim larly to the metal well section 12, em-

dies an annular outwardly-extending flange 74 and a combined positioning and embodies a sloping upper surface 77 and is sealed and secured in position on the flange 32 by a gasket 7 6 and screws .79, respectively, the latter of which extend into the well cover 15. V

The collar- 'member 67 embodies adongi- I tudinal cylindrical portion 80, a sloping .under surface 82 for cooperation with the sealing gasket 78 and the sloping upper surface 77, and a laterally-outwardly-projecting annular flange 85, for securing the collar member 67 to the bushing-supporting member 65, by means of bolts86 which extend between the flanges 74 and 85. t

The porcelain shells 68 have portions that are nested and cemented in position, one within another, in a usual manner. A flange 87, of the bottom shell 68, rests on a sealin gasket 88 on a shoulder 89 in the collar 6 and is secured in position in the cylindrical portion 80, by a body of cement 90. The upper shells '68 are smaller than the lower shells. by reason of the tapered upper end (not shown) of the condenser bushing member 64, and an insulating filling compound 92 is disposed between the shells 67 and the condenser member 64.

The stop terminal structure comprises a collar member 94 that is secured to the top shell 68, as by cementing and a member 95 having a lateral lower flange 96 by which it is secured to the collar 94 by. means of screws 97. The member 95 further comprises liftinghook portions 99 and a terminal clip 100.

After placing the well structure in the opening 7, the stud 46, at the lower end thereof, may be moved laterally, to adjust the stationary contact member thereof relative to the movable element of the interrupter, as

above mentioned, by shifting the flange 18 on the flange 9, as in a ball-and-socket Joint.

Since the distance frolnthe stud 46 to the flange 9 is relatively great, a very slight movement of the well structure, to change the angular position of the longitudinal-axis thereof, effects a relatively great adjustment of the stud 46. Slight adjustments of the latter are, therefore, almost imperceptible at the parts 9 and 18.

When it is desired to ship the entire structure, the condenser bushing 6, with .its a-ppurtenant permanently attached parts, such as the condenser member 64, the supporting cylinder 65,"the collar 67, the shells 68 and the top terminal structure 70 may be easily detached by removing the screws 79.

In effecting the above detachment, the cable 48 is also detached from the top terminal structure 70 and allowed to fall into the -well 4, when the bushing i'sremoved. This feature is provided because the lower end of the cable must be securely fastened and is not sogaccessible in the field where its top connection may easily be made.

Thus, the condenser bushing, with its attending parts, as one unit, and the well structure with the cable 48 and the remaining interrupter parts as another unit, may conveniently be separately shipped for reassembly inthe field without adjustment and dif- 'ficult connections. At the place of installa? tion, the outer end of the slackened cable 48 is removed from the well, the interrupter casing and the well are supplied with oil, the cable is threaded through the condenser member 64 and secured to the terminal 70 and the well cover 15 is placed in position, all of which operations may easily and conture 4 is thoroughly sealed,

veniently be performed outside the interrupter casmg.

Since, as above described the well structhe oil-in the well and the oil in the interru ter casing, the levels ofwhich are represente by lines a: and y, respectively, are efiectively separated.

Thus, when carbon and metallic particles are given 011? by the interrupter contact members when the latter are operated under heavy loads, and are suspended in the casing oil, the oil in the well is maintained free thereof. This feature is important because any reduction of the insulating value of the oil along the tapered or stepped lower portion of the condenser member 64, might result in breakdown of the bushing and damage to or del struction of the same and surrounding parts.

Further, since a space for gas must be maintained above the. main body of oil Y in the interrupter, the well structure 4 permits a higher level of the oil X therein to be employed, thus providing a more eflective protection of the condenser element 64 than if 'ular forms of my invention,

wall member having a therethrough, a casing the well were not employed.

In the modification of my invention illustrated in Fig. 2, in which corresponding parts are designated by corresponding reference characters, the construction is substantially the same as that above described, except that the well structure 4 instead of being removably and adjustably mounted on the cover member 2, is permanently fixed thereto, as by welding or brazing the metal section 12 thereof to the cover. member:

This construction prevents. adjustingthc stud-46, at the bottom of the well, in the manner above described, but is a feature of economy over the other construction;

Other slight differences in this form of my invention are that the flange 20, between-the metal section 12 and the insulating section 14 of the well, is a separate element, secured to the metal section by screws 102, and the screws 34 extend into the cover member 2, instead of into the well section 12.

While I have shown and described particchanges may be eflected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

claim as my invention:

1. A high-voltage structure comprising a bushing opening of substantially cupshape embodying an insulatin rtion and disposed locally about the bus mg with its open-end perimeter secured to the wall member around said opening, a complete bushing unit having a portion 1n said casing and conducting means. extending through the bushing and the casing.

2. A high-voltage structure comprising a Wall member having a bushing opening therethrough, a casing of substantially cupembodying insulating and metal sections and disposed locally ing with its open end adjacent to the wall opposite said opening, said casing being suported solely by said wall member, a complete ushing unit having a portion insaid casing, and conducting means extending through the bushing and the casing.

3. A high-voltage structure comprising a wall member having an opening therethrough, a local bushing well structure sealed to said wall member opposite said opening and including a cover member, and a bushing extending through said cover member in sealed relation thereto at a position adjacent thereto. 1

4. A high-voltage structure comprising a wall member having a bushing opemng therethrough and an annular flange projecting substantially normal to the wall around the opening, and means for receiving a portion of a complete bushing unit including a local bushin g well structure having a bottom portion insertable through said opening and a laterallyextending outer flange dis osed on said first flange in sealed relations t ereto.

- 5. A high-voltage structure comprising a wall member having a bushing opening therethrough and a sloping seat portion around the opening and a local bushing well structure that is independent of a complete bushing structure which 'it is to receive and is disposed opposite said opening with a portion cooperating with said sloping seat portion for angularly adjusting the well structure relative to the wall member prior tothe reception of the bushing structure.

6. A high-voltage structure comprising a wall member having a bushing opening therethrough and an annular flange projecting substantiall normal to the wall around the opening em dying an inwardly-sloping seat portion, and a local bushing well structure having a bottom portion insertable through said opening and a laterally-projecting outer flange cooperating with said resting the well structure on the wall member and an larlyadjusting the well relative to the wali said well structure being adapted for the reception of a portion of an independent and complete bushing-unit structure.

7. A high-voltage structure comprising a wall member having a bushin opening therethrough, a local bushing we the reception of a portion of a complete bushing unit and secured to the wall member opposite said opening and including means or conducting current through the wall of the well, and means for adjusting said conducting means relative to a device outside the well with which it is to cooperate.

8. A high-voltage structure comprising a seat portion for.

structure for I cured to the wall member opposite said opening, means at the bottom of the well for conducting current through the wall thereof including a conductor projecting from the hottom of the well, and means for adjusting said conductor angularly relative to the axis of said opening.

high-voltage bushing structure comprising a wall member having a bushing openng therethrough, a local bushing well struc ture secured to the wall opposite said opening, means for conducting current through the bottom of the well including a conductor for extension along the axis of the well therein, and a complete bushing unit for insertion in the well over said conductor.

10. A high-voltage bushing structure comprising awall member having abushing opening therethrough, a local bushing well structure secured to the wall opposite said opening, means for conducting current through the bottom of the well including a flexible conductor in the well, and a bushing for insertion in the well and having a central opening for the reception of said flexible conductor.

11.' A high-voltage structure comprising a wall member having a bushing opening therethrough, a local bushing well structure secured to the wall opposite said opening, a complete bushing unit having a portion in the well, a transformer element disposed aroundsaid portion and a conducting lead for said element extending through the wall of the well in sealed relation thereto.

12. A high-voltage structure comprising a fluid-containing casing including a metal cover member having an opening therethrough, a well structure comprlsing an upper metal section sealed to the cover member around said opening, a bottom insulating section sealed to said upper section, a lid member for the well structure having an opening therethrough, and a complete condenser bushing unit .supported in the opening in said lid member in sealed relation thereto adjacent thereto.

13. A high-voltage structure comprising a fluid-contaming casing including a metal cover member having an opening therethrough, a

well structure comprising an upper metal sec-. tion sealed to the-cover member around said opening, a bottom insulating section sealed to said upper section, and having downwardly converging side walls, a lid member for the well structure having an opening therethrough, and a complete condenser bushing unit supported in the opening in said lid memher in sealed relation thereto adjacent thereto, said bushing having a portion of substantially uniform relatively small diameter extending through said upper metal section and a tapercd lower end portion in said bottom insulating section.

14. A-high-voltage structure comprising a fluid-containing casing including a metal covopening, a bottom insulating section sealed to i said upper section, a lid member for the well structure having an opening therethrough, a complete condenser bushing unit extending through the opening in the lid member and means on the bushing for supporting the same on, and sealing the same to, said lid member.

15. In combination, a Wall member having a bushing opening therethrough, a bushing shield of substantially cup-shape extending transversely to said wall with its open end opposite said bushing opening, a complete bushing unit having a portion for disposition in said shield, and means for supporting the shield and providing for the removal of said unit while said shield remains in place.

16. In combination, a well member having a bushing opening therethrough, a bushing shield of substantially cup-shape extending transversely to said wall with its open end opposite said bushing openin a complete bushing unit-having a portion ibr disposition in said shield, and means for adjustably securing said shield in position and providing for the removal ofsaid unit while said shield remains in place.

17. In combination, a wall member having a bushing opening therethrough, a bushing shield of substantially cup-shape extending transversely to said wall with its open end opposite said bushing opening, a complete bushing unit disposed partially inside and partially outside said shield, and means for closing said open end and supporting the bushin unit.

18. combination in a high-voltage circuit-interrupting device, a casing having a bushing opening, and an insulating element of substantially cup-shape dis osed in the casing opposite said opening in ependent of.

to said wall with its open end secured thereto in position adjacent to, and in register with, said opening, and. a complete bushing unit removably secured in position independently of the shield witha portion in said shield and a portion projecting from the opposite side of said wall at which the bushing is disposed.

20. In combination, a wall member having an opening therethrough, a shield of substantially cup-shape extending transversely to said wall opposite said opening and having a laterally outwardly projecting portion removably secured to said wall at the side of the latter opposite to which the major portion of theshield is disposed, and a complete bushing unitremovably secured in .pofition with a portion in said shield and a portion proj therefrom.

Y 21. Incombination,in ahigh-voltage structure, a vessel for containing a fluid-immersed electrical device, a complete bushing unit extending through a wall "of the vessel and means supported inde endentl oi, said unit said se said opening and having a later ing portion adjacent to the wall for attachfor segregating said old from a 'fluid surrounding a portion of the bushing unit and providing for the removal of said unit while gating means remains in place. 22. 7' combination, a wall member having an opening therethrough, a shield of substantially cup-shape extendin transversely to said wall with its open end in re ister with y-extendment thereto, and a complete bushing unit removably secured-in position with a portion in said shield and a portion projecting therefrom.

23. In combination, a wall member having an opening therethrough, a shield of substantially cup-shape of smaller diameter than said opening extending transversely to said wall with its open end in register with said opening and having laterally-extending portlons adjacent to the wall for attachment thereto, and a'complete bushing'unit removabl secured in position with a portion in said s ield and a portion projectin therefrom.

In testimony whereof: I have hereunto subscribed my name this 10th day of May, 1927. i JESSE E. MATEER.

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