US3377601A - Mobile electrical transformer apparatus having means for moving the transformer between operating and transit positions - Google Patents

Description

Apnl 9, 1968 H. M. DONEGAN 3,377,601

MOBILE ELECTRICAL TRANSFORMER APPARATUS HAVING MEANS FOR MOVING THE TRANSFORMER BETWEEN OPERATING AND TRANSIT POSITIONS 3 Sheets-Sheet 1 Filed Oct. 27, 1966 April 9, 1968 H. M. DONEGAN 3, MOBILE ELECTRICAL TRANSFORMER APPARATUS HAVING MEANS FOR MOVING THE TRANSFORMER BETWEEN OPERATING AND TRANSIT POSITIONS Filed Oct. 27, 1966 3 Sheets-Sheet n O M 9 4E Km mm %m T WM m M a V W @m m B E wm v/ Ag (U 5 Mm m 9. m LW y April 9, 1968 H. M. DONEGAN 3,377,601

MOBILE ELECTRICAL TRANSFORMER APPARATUS HAVING MEANS FOR MOVING THE TRANSFORMER BETWEEN OPERATING AND TRANSIT POSITIONS Filed Oct. 27, 1966 3 Sheets-Sheet 5 United States Patent 3,377,601 MOBILE ELECTRICAL TRANSFORMER AP- PARATUS HAVING MEANS FOR MOVING THE TRANSFORMER BETWEEN OPERAT- ING AND TRANSIT POSITIONS Howard M. Donegan, Muncie, Ind., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 27, 1966, Ser. No. 590,045 3 Claims. (Cl. 336-65) ABSTRACT OF THE DISCLOSURE Mobile transformer apparatus including a transformer disposed on a carriage, and means for moving the transformer relative to the carriage between operating and transit positions.

This invention relates in general to electrical inductive apparatus, such as transformers, and more particularly to mobile electrical inductive apparatus.

Electrical apparatus, such as electrical transformers, specifically designed for mobile use, must meet predetermined space requirements at least while in transit, both as to the height and width of the apparatus. The increasingly higher voltages which are being used by electrical utility companies have made it necessary for the designer of mobile apparatus to resort to such expedients as removing the electrical bushings during transit, or providing electrical bushings which are movable relative to the casing of the apparatus, which allows the bushings to be moved between the transit and operating positions, as required. For example, US. Patent 3,258,524, assigned to the same assignee as the present application, teaches an arrangement which allows electrical bushings to be moved relative to the casing of the apparatus, without rotating through a seal.

Removing the high voltage electrical bushings each time mobile electrical apparatus is to be moved, is generally undesirable. In order to remove the bushings, several hundred gallons of liquid dielectric must be removed from the tank, which exposes the electrical windings to the atmosphere. Thus, the tank would have to be refilled at the operating site under vacuum, in order to remove air absorbed and trapped in the windings.

Providing adjustable bushing mounts has solved the space problem in certain applications, and will continue to do so up to certain voltage ratings. However, as the voltage ratings reach 345 kv., and higher, into the EHV (extra high voltage) class, the bushing size becomes such that adjustable bushing mounts may not be practical. Therefore, it would be desirable to provide new and improved mobile electrical apparatus Which 'will provide the necessary electrical clearances between the bushing terminals, and between the bushing terminals and ground, when operative, and which will also meet highway space limitations set by the Interstate Commerce Commission and/ or the State, while in transit, without resorting to adjustable bushing mounts, or the removal of the electrical bushings.

Accordingly, it is an object of the invention to provide new and improved mobile electrical apparatus.

Another object of the invention is to provide new and improved mobile electrical apparatus which will provide the necessary electrical clearances while operating, and meet predetermined smaller space limitations while in transit.

A further object of the invention is to provide new and improved mobile electrical apparatus which will provide the necessary electrical clearances while operating, and

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which will meet predetermined smaller space limitations while in transit, without removing the electrical bushings, and without providing adjustable bushing mounts.

Briefly, the present invention accomplishes the above cited objects on mobile electrical apparatus, by reducing the angle of inclination of the high voltage bushings from the horizontal, which disposes the terminal of one or more of the bushings closer to the carriage bed of the mobile electrical apparatus than the required electrical clearance. This is accomplished while maintaining the required electrical clearances between the various bushing terminals themselves. For example, on three-phase mobile electrical apparatus, the centrally disposed high voltage bushing is lowered to that angle which allows the remaining two high voltage bushings to be lowered to within the maximum height limitation, and to be moved inwardly towards each other to within the maximum width limitation. Thus, the mobile electrical apparatus may be transported to the intended operating site without exceeding the maximum applicable height and width limitations.

The mobile electrical apparatus also includes means for moving the electrical transformer to raise the electrical bushings secured thereto above the mounting bed of the movable carriage to the required height. Upon reaching the operating site, the transformer moving means is operated or actuated, to move the transformer and raise the electrical bushings to an operating position which provides the necessary electrical clearance from the bushing terminals to the carriage bed. Since the required electrical clearances already exist between the various electrical terminals of the high voltage bushings themselves, the mobile electrical apparatus is ready for operation as soon as the transformer has been moved to the operating position, and all electrical connections made. To move the mobile electrical apparatus to the next operating site, merely requires that the electrical apparatus be moved to the transit position. In one embodiment of the invention, the transformer portion of the mobile electrical apparatus is lifted vertically by lifting means, and in another embodiment of the invention the transformer is pivoted between the transit and operating positions by pivot means.

Further objects and advantages of the invention will become apparent from the following detailed description,

taken in connection with the accompanying drawings, in which:

FIGURE 1 is an elevational view of mobile electrical .inductive apparatus constructed according to an embodiment of the invention;

FIGS. 2 and 3 are elevational and plan views, respectively, comparing the high voltage bushing positions of electrical inductive apparatus constructed according to the teachings of the invention, with the bushing positions of prior art electrical inductive apparatus; and

'FIG. 4 is an elevational View of mobile electrical inductive apparatus constructed according to another embodiment of the invention.

Referring now to the drawings, and FIG. 1 in particular, there is shown an elevational View of mobile electrical inductive apparatus 10, such as a mobile substation, which includes a three-phase electrical transformer 12 disposed upon the bed 14 of a carriage or trailer 16. The associated switchgear, such as lightning arresters, grounding switches, and the like, which would also be mounted on the bed 14, and the tractor for pulling carriage 16, are not shown in the drawings for purposes of simplicity.

The bed 14 of carriage 16 may be constructed of two main, spaced apart, structural members 18 and 20, which provides space between the members for a portion of transformer 12 to extend.

posed within the tank 22, and this fluid may be cooledby external heat exchanger means 40, connected to tank 22 through suitable piping means, and force circulated by pumping means 42, if desired.

A conventional prior art high voltage bushing arrangement for high voltage bushings 24, 26 and 28, is disposed on mobile electrical inductive apparatus, is shown in FIGS. 2 and 3 in dotted outline, which figures are elevational and plan views, respectively. This prior art bushing arrangement, which provides. the necessary clearance 50 from the centrally disposed electrical bushing 44 to the carriage bed 14, may cause electrical bushings 26 and 28 to exceed the maximum highway height limitation 52 by the distance 54 shown in FIG. 3, and to exceed the maximum highway width limitation 56, by the difference between widths 58 and 56, when applied to certain voltage classes.

This invention solves these space problems, without removing the electrical bushings during transit, and without utilizing bushing mounts which allow movement of the bushings relative to the transformer casing, by reducing the angle of elevation 60 of the centrally disposed electrical bushing 24, relative to carriage bed 14, to the angle which allows the height of electrical bushings 26 and 28 to be reduced to within the maximum shown at 2, and which allows electrical bushings 26 and 28 to be moved closer together, to within the distance indicated at 56. The bushing positions, according to the teachings of the invention, are shown in FIGS. 2 and 3 with solid lines.

The solid line position of electrical bushings 24, 26 and 28 shown in FIG. 2 is shown in FIG. 1 in dotted outline, which is the in transit position of transformer 12.

Electrical clearance between the electrically conductive end portions 60, 62 and 64 of electrical bushings 24, 26 and 28, is not the only condition to be satisfied, howiied. It will be noted that the dotted line in transit position of electrical bushing 24 provides less than the electrical clearance =0 required between the conductive portion 60 of the bushing and the carriage bed 14. Carriage bed 14 extends outwardly past the ends of the high voltage bushings, in order to accommodate the switchgear necessary for the operation of the mobile electrical substation. Therefore, electrical clearance between the high voltage bushings and the carriage bed is essential.

In this embodiment of the invention, electrical clearance 50 is provided by lifting means 70, which vertically raises transformer 12 to provide the required space between high voltage bushing 24 and carriage bed 14. Lifting means 70 may be of any suitable type, such as bydraulic jacks 71, or manual type jacks. Transformer 12 may have a plurality of projecting support members, such as those shown at 72 and 74, which are guided vertically by guide means 76 and 78, respectively.

Lifting means 70 should have auxiliary means for supporting transformer 12 in the operating position, independent of the means 71 for raising the transformer. For example, heavy bolt members such as those shown at 80, 82 and 84 may be inserted into suitable openings in the guide means, just under support members 72 and 74.

Lifting means 70 may also haxe auxiliary interim support means, which supports thetransformer during its transition between the operating and transit positions, and which is also independent of means 71. For example, each guide means, such as guide means 78, may include a rack 86 with an associated pinion 88 disposed on support means 74. The pinion 88 may be arranged to allow movement in an upward, or a downward direction, but

not both at the same time, to provide safety for, the transformer as it is being raised. Or, if the lifting means is manual, such as a mechanical jack, which lifts and lowers the transformer in discrete steps, pinion 88 may be arranged to prevent rotation in either direction, until tripped just prior to the initiation of a step, to allow an incremental rotation of the pinion equal to one discrete step.

FIG. 4 is an elevational view of mobile electrical apparatus 10, illustrating another embodiment of the invention. Like reference numerals in the various figures indicate like components. In this embodiment of the invention, instead of vertically lifting the transformer 12, transformer 12 is pivoted about a predetermined point to raise the position of the high voltage bushings relative to carriage bed 147 More specifically, bearings, such as that shown at are welded or otherwise secured to the transformer casing 22, at substantially the balance point of the transformer, and bearings, such as bearing 162, are welded or otherwise suitably attached to the main, spaced structural members 18 and 20. A shaft 104 is disposed through the openings in the bearings, which allows transformer 12 to pivot relative to carriage bed 14. In FIG. 4, the in transi position of transformer 12 is'shown in solid lines, and the operative position is shown with dotted lines. Since transformer 12 is substantially balanced on the shaft 104, it may be pivoted about shaft 104 with relatively little eflort. For example, a manually operated gearing arrangement may be employed, which has a suitable mechanical advantage which allows the transformer 12 to be cranked between the operative and transit positions. Stops may be used to solidly position transformer 12 at each of the extreme positions of the pivot angle, such as stop 112 for positioning the transit position, and stop 114 for positioning the operative position. Openings in the structural members, such as openings 116- and 118 may be aligned with corresponding openings in the stops 112 and 114, when at one -or the other of the two positions, which allows bolts to be used to secure the transformer in the desired position.

Thus, in summary, there has been disclosed new and improved mobile electrical inductive apparatus, which enables higher voltage class apparatus to be utilized mobile, without resorting to removal of the high voltage bushings during transit, or requiring adjustable bushing mount arrangements in which the bushings may be moved relative to the casing of the electrical apparatus. According to the teachings of this invention, the positions of the high voltage bushings may be changed between transit and operating positions by moving the transformer relative to the carriage bed of the mobile electrical apparatus, in a manner which changes the spacing between the high voltage bushings and the carriage bed. While these teachings have been illustrated with respect to three-phase transformers, it will be obvious that they apply equally to single-phase mobile transformers which are too large to meet highway limitations using conventional techniques.

Since numerous changes may be made in the abovedescribed apparatus and different embodiments of the invention may be made without departing from the spirit thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense.

I claim as my'invention:

1. Mobile electrical apparatus comprising:

an electrical transformer having a tank portion and high and low voltage bushing assemblies,

a carriage having a bed portion supported by a plurality of wheels,

first means supporting said electrical transformer in a predetermined position relative to the bed portion of said carriage,

jacking means for moving said electrical transformer between at least first and second predetermined positions, to change the spacing between said high voltage bushings and said bed portion, the first predetermined position providing electrical clearance between said high voltage bushings and said bed portion, which allows said electrical transformer to be energized at its operating potential, the second predetermined position reducing the overall height of said electrical transformer within a predetermined maximum,

interim support means for supporting said electrical transformer independent of said jacking means while said transformer is being moved between said first and second position,

and support means for supporting said electrical transformer in said first position, independent of said jacking means.

2. The mobile electrical apparatus of claim 1 wherein said jacking means moves said electrical transformer in predetermined vertical steps, and said interim support means maintains said transformer at each step, independent of said jacking means, at least until said jacking means initiates the next step.

3. Mobile electrical apparatus comprising:

an electrical transformer having a tank portion and high and low voltage bushing assemblies,

a carriage having a bed portion supported by a plurality of wheels,

pivot means for pivotally supporting said transformer relative to said carriage,

means for rotating said electrical transformer about said pivot means, between at least first and second predetermined positions, to change the spacing between said high voltage bushings and said bed portion,

stop means for mechanically limiting the pivot angle of said electrical transformer,

and means for mechanically securing said transformer relative to said carriage at predetermined locations in the pivot angle.

References Cited FOREIGN PATENTS 869,979 11/1941 France. 236,167 6/1945 Switzerland.

LARAMIE E. ASKIN, Primary Examiner.

25 T. I. KOZMA, Assistant Examiner.

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