US1224225A - Transformer. - Google Patents

Description

F. SIEBER.

TRANSFORMER.

APPLICATION FILED JUNE 24. 1912.

Patented May 1, 1917.

r- INVENTOR ATTORNEY 0..Pnoru-ummmasmucmu. 0 c.

inrrnn srariis FERDINAND SIEBER, 0F l/ADO LIGURE, ITALY, ASSIGNOR TO WESTINGHOUSE ELEC- TRIC AND MANUFACTURING COMPA TRANSEQBMER.

Specification of Letters Patent.

Patented May 1, 1917.

Application filed. June 24, 1912. Serial No. 705,496.

To all whom it may concern:

Be it known that l, FERDINAND SIEBER, a subject of the Emperor of Austria, and a resident of Vado Ligure, Italy, have in vented a new and useful mprovement in Transformers, of which the. following is a specification.

My invention relates to transformers and more particularly to transformers in which the coils are disposed one above another with layers of insulating material inserted between them. With this arrangement, it has been found that a very considerable mechanical pressure is exerted upon the coils, and especially upon the lower coils, of trans former windings, both by reason of the weight of the superposed coils and also by reason of the end pressure to which the combined windings are usually subjected in order to compress them between the retaining flanges, rings or other devices employed to fix the windings securely upon the core. The pressure to which the coils are thus subected tends to damage the insulating covering of the conductors and also the layers of insulation between the coils. Furthermore, when a coil consists of several turns in one layer, as is generally the case, the said high pressure has the further disadvantage that it tends to crush the separate turns out of their proper places in the coil.

One object of my invention is to provide means for relieving the coils of transformer windings from the mechanical pressure referred to above, and for firmly supporting the windings, as a whole,in position upon or around the core.

Another object of my invention is to provide-novel means for bracing the coils of the transformer against axial movement in such a manner that a. given transformer may be placed in a tank of smaller cross-sectioual area than has heretofore been customary.

My invention may be carried out in various ways and the means employed may assume various forms. For the purpose of illustration the invention will be described as applied to a transformer of the core type, with the aid of the accompanying drawing. in which Figure 1 a view, partly in section, on the line 1,I of Fig. 2, of a portion of a winding of a core type transformer having this invention applied thereto; Fig. 2 is a top plan view of the portion of the transformer and winding shown in 1, partly in section on the line IIII; Figs. 3 and lshow different forms of supporting pieces which may be used with the invention, and

Figs. 5 to 8 illustrate modifications.

Referring to Figs. 1 to 3 of the drawing, a number of coils 1, 9., 3 are supported, one above another, by a flange 4 of the lower end ring 5 of a core transformer, the position of the lowest coil 1, relatively to the transformer core plates 6, being adjusted by means of blocks 7 of insulating material and adjustable bracing bolts '8 which project through holes in the flange 4 and are secured in position therein by means of nuts 9, 10. It will be noted that the bracing bolts 8 are supported upon the end frames 5 of the core member 6, and are comparatively short since they do not act as tie-bolts which formerly were the usual means for bracing the coils in a transformer of this character. The function of the tie-bolts 8 is to abut against the outer end of the built-up columns of the spacing blocks, thereby serving to brace the coils against axial displacement when they are subjected to abnormal stresses. This form of structure eliminates the necessity of providing extensions upon the core member or the end frames of the core member, that project beyond thecoils whereby the usual tie-bolts exterior of the coils may be extended the length of the transformer core. In consequence of the present arrangement, the transformer constructed as I have shown nay be admitted. into a containing tank having a comparatively small cross-sectional area.

In order to prevent the pressure caused by compression of the winding between the end rings from being transmitted to the conductors of which the windings consist. each of the coils 1, 2 and 3 is embraced and supported, at various points by supporting pieces 11 and 12 which may be made either of metal or of a hard insulating material, such as wood. The lower supporting piece 11 for each coil, a perspective view of which is shown in Fig. 3, is formed as a trough to receive the coil which is covered and protected by an upper piece 12. the downwardly projecting portions 13 of which abut against the upwardly projecting portions 14 of the lower supporting piece 11. This arrangement completely relieves the conductors of a coil from all mechanical pressure caused by the compression and securing of the com= bined windings in position upon the transformer. A segmental piece 15, which should be made of insulating material when the supporting pieces 11, 12 are of metal, but which may be made of either metal or insulating material if the pieces 11 and 12 are of insulating material, is inserted between the lower supporting piece 11 for a coil and the upper protecting piece 12 for the next lower coil, these segmental pieces 15 being shaped as is clearly shown in outline in Fig. 2.

Fig. l shows, in section and in plan, a modified form of supporting piece consisting of a metal strip 16 bent into a U-shape. This strip is passed over the coil and a closing piece 17 is inserted between the open ends and secured by means of screws 18 and 19 or by other suitable means.

Fig. 5 illustrates the invention as applied to a winding in which a coil 3 is spaced from an adjacent coil 2'by two pieces 11 and 12 and a piece 15 and by additional pieces 15 and 15; the supporting arrangements are otherwise substantially the same in this case as in that already described with reference to Figs. 1 to 3.

Instead of embracing a single coil by the supporting pieces 11, 12, as shown in Figs. 1 to 3 and in Fig. 5, several coils might be embraced by one pair of such supporting pieces, as shown in Fig. 6. Inthis figure, three coils 20, 21 and 22 are shown as supported. by one pair of supporting pieces 11 and 12, the coils being separated by insulating layers, in the usual manner.

In those cases in which the coils of the winding are of considerable width it is preferable to divide such coils into two or more parts and provide the supporting pieces 11 and 12, with additional intermedate projecting portions A and B, as shown in Figs. 7 and 8.

Although the invention has been described above as applied to a transformer of the core type, it is to be understood that it is also applicable, with slight modifications, for employment with transformers of the shell type.

From the foregoing, it will be seen that the pressure due to the weight of the superposed coils and also that due to the compression of the combined windings between the end supporting pieces of the transformer, is entirely taken up by the rigid supporting pieces 11 and 12 which embrace portions of each coil, or of several coils together, of a winding at different points in its periphery, and that thereby the conductors of which the coils consist are entirely relieved of all such pressure, thus protecting the insulation of the conductors from injury, and the various turns of each layer of a coil from being displaced, under the effect of said pressure. Moreover, it is apparent that the supporting pieces 11 and 12 are spaced from one another, as shown in Fig. 2, in order to provide ventilating passages between the coils of the transformer. In this manner, the coils are well ventilated in addition to being relieved from compressive stresses.

1 claim as my invention:

1. A transformer comprising a core member, a plurality of superposed coils therefor, peripherally-spaced columns of recessed blocks supported upon said core member and embracing the coils to relieve them of external pressure, and bracing bolts supported by the core member and abutting against the ends of said columns for prc venting said blocks from moving axially.

2. A transformer comprising a core member, end frames therefor, a plurality of superposed coils, blocks interposed betweenadjacent coils to space them from one another and to embrace portions only of the coils in order to relieve them from pressure, said blocks being arranged in a plurality of peripherally spaced columns, and bracing bolts supported. on both end frames and abutting against both ends of said columns for preventing said blocks from moving axially.

3. A transformer comprising a core mem ber, a plurality of superposed coils embracing one'leg thereof, and blocks interposed between the adjacent coils, said blocks being recessed and embracing the coils to relieve them of external pressure.

4-. A transformer comprising a core member, a plurality of superposed coils embracing one leg thereof, and recessed blocks interposed between adjacent coils and embracing portions only of the coils to relieve them from pressure, said blocks being arranged in a plurality of spaced columns.

In testimony whereof, I have hereunto subscribed my name this third day of June, 1912.

F. SIEBEB. lVitnesses:

RAY Rnrvm'rlorry Tns'rn, Y. VALvAssURE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). O.

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