US1620411A - Transformer - Google Patents

Description

March 8, 1927.

E. J. TEMPLE TRANSFORMER Filed March 20, 1925 Invemtor":

Elmer J.Temp|e y hwy His Attorney.

Patented Mar. 8, 1927.

UNITED STATES PATENT OFFICE.

ELMER J. TEMPLE, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELEG- TRIG COMPANY, A CORPORATION OF NEW YORK.

TRANSFORMER.

Application filed March 20, 1925. Serial No. 17,037.

. My invention relates to encased transformers and more particularly to transformers of this type which are of very large size and capacity. It is usually desirable that 6 the core and coils of a transformer of the encased oil immersed type be shipped from the factory in upright position and immersed in oil in the permanent casing for protection against moisturewhile in transit. Shipment of the core and coils in'their own casing, whether of the oil immersed type or not, has the further advantage that freight charges are often substantially reduced because the number of large volume units in the shipment is reduced and freight rates are frequently' based on volume. The slze and capacity of transformers have been increased greatly in the past and undoubtedly w1 ll continue to increase in the future so that it 29 is becoming increasingly diflicult to meet the demand for these large sizes and at the same time to comply with the limitations in height imposed by railroad clearances. The general object of the invention is to provide an encased transformer which may be safely and conveniently shipped with the core and coils assembled in the casing but which is of such excessive height when completely assembled and ready for service as to render shipment impracticable.

In very large encased transformers, 'there is always a considerable clearance between the top of the transformer itself and the cover of the casing in order to provide sufli- 35 cient space for various accessories such as the inner extensions of high tension bushings, the necessary leads and connections and, in the case of oil immersed transformers, for suflicient oil to cool the transformer properly. Advantage is taken of the fact that these accessories above the top of the transformer are, or may easily be made, re-

movable and the casing formed in two parts divided by a tight joint near the top of the transformer. In accordance with my invention, the upper edge of the lower section of the casing is formed to receive a tightly fitting cover, preferably the same cover that is used to close the top of the complete casing while in service, so that the transformer may be properly protected from moisture during shipment. The invention thus permits the transformer tobe shipped conveniently and safely and without exceeding permissible shipping dimensions.

the upper section of the transformer casing,

The invention will be better understood from the following description taken in connection with the accompanying drawing in' which Fig. 1 shows an encased oil immersed transformer constructed 1n accordance wlth the invention; Fig. 2 shows the lower section .of the transformer casing closed by a suitable cover' and ready for shipment with the transformer enclosed therein; Fig. 3 shows -to permit expansion and contraction of the oil under the influence of variations in temperature. A rupturable diaphragm 13 in a large pressure relief pipe 14 serves to relieve accidental excessive pressure within the casing 11. High tension bushings 15 and low tension bushings 16 insulate the high and low tension transformer leads respectively where these are brought out through the casing from the transformer.

As is usual in a large transformer,there is a considerable clearance between the top of the transformer 10 and the cover of the casing to provide space for the oil necessary in the proper cooling of the transformer, for the inner extensions of the bushings, and for the transformer leads and connections and other necessary accessories. The casing 11 comprises an upper, section17 and a lower section 18 with a tight joint between them near the top of the transformer. The joint may be formed by projecting flanges 19 and 20 on the meeting edges of the upper and lower sections of the casing, the flanges being bolted together with a gasket between them to make the joint oil tight as shown most clearly in Fig. 4. The casing has a cover 21 bolted to' a flange 22 on the upper edge of the upper section 17 of the casing, a. gasket making the joint tight. Lifting rods 23 having eyes threaded onto their upper ends extend down through the edge of the cover and the projecting flanges'22, 19 i and 20 to the projectin ends of supporting bars 24 under the trans ormer casing. Each of these lifting rods 23 is in two sections connected by a threaded sleeve just above and bearing upon the flange 19 at thejoint between the two sections of the casing.

There is beginning to be a demand, which will undoubtedly increase in the future, for encased transformers of such large capacity that the height of the casing must exceed the limit which it is possible to ship. As is customary, the accessories such as the bushings, pressure relief pipe and auxiliary expansion chamber are detachably mounted .on the casing and may be removed from the casing for shipment. It is very desirable to ship the transformer inside its casing to protect it from atmospheric moisture and it is also not practicable to ship a very large transformer in its casing in any other than its normal upright position because ofits weight and the consequent impracticability of supporting it in' the casing except in its normal position. The invention permits these dificulties to be overcome by; forming a separable tight joint in the casing to provide a section of the casing which does not exceed the permissible shipping height and in which the transformer may be entirely enclosed and protected during shipment. The joint is preferably near the top of the transformer but may be anywhere desired 7 below the top of the casing down to a level near the top of the transformer so long as it is so located that the height of the section of the casing below the joint does not exceed the permissible shipping height. The upper sectionv 17 of the casing is removed after unbolting the- flanges 19 and 20 and removing the upper sections of the lifting rods 23 and the connecting sleeves 25. In

- of the lower section of the casing before the upper section is removed. Any inside connections such as the transformer leads 26 may be coiled up on top of the transformer. If cooling coils such as the coils 27 shown in Fig. 4 are used,they may be provided with a union 28 at the level of the top of the lower section 18 of the casing so that the coils may be separated into two parts which may remain in the respective sections of the casing during shipment.

The top of the lower section 18 of the casing is closed tightly by a cover and. the whole is preferabh filled with ,oil, if the transformer is of t e oil immersed type, to exclude all air. The flange 20 is preferably a duplicate of the flange 22 so that the'mai n cover 21 of the casing will fit either flange and may be used during shipment to close the lower section of the casing. When the main cover 21 is so used, any small openings, such as those for the bushings and various pipe connections, may be closed by suitable temporary covers. The lifting eyes from the tops of the lifting rods '23 may be screwed onto the upper ends of the lower casing so tall as to exceed shipping limita-- tions maybe conveniently protected and shipped in its own permanent .casing.

lVhat I claim as new and desire to secureby Letters Patent of the United States, is:

1. A transformer having an enclosing casing extending above the transformer to provide a space between the. top of the transformer and the top of the casing, said casing .comprising separable upper and lower sections, and a cover formed to fit upon the 2. A transformer having an enclosing casing. extending above the transformer to provide a space between the to of the transformer and the top of the casing, said casing comprisingseparable upper and lower sections and a top cover, the upper edge of said lower section being formed to fit and receive said cover with the upper section of said casing removed, the joint between said se arable sections being sufficiently near t e top of said casing to permit the transformer to be enclosed in said lower section with said cover assembled thereon.- a

3. A transformer having an enclosing casing extending above the transformer to provide a space between the top of the transformer and the top of the casing, said casing comprising separable upper and lower sec-' tions and a top cover, each of said sections having a flange at its upperedge formed to fit and receive said cover, whereby said cover may close the complete casing with its two sections assembled or the lower section of said casing with the upper section removed,

the joint between said separable sections vide a space between the top of the tr I30 former and the top of the casing, said casing comprising separable upper and lower sections, the upper edge of each section being formed to fit and receive a cover and the joint between said separable sections being sufficiently near the top of said casing to permit the transformer to be enclosed in said lower section with a cover assembled thereon, lifting rods secured to said casing at-its upper and lower ends, each of said liftin rods having a separable joint at the joint etween the two sections of said casing, and means for securin the upper end of the lower section of each lifting rod to the upper end of the lower section of said casing with the upper section of the casing and the upper sections of the lifting rods removed.

In witness whereof, I have hereunto set my hand this 18th day of March 1925.

ELMER J. TEMPLE.

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