US1652938A

US1652938A - Inductance coil

Info

Publication number: US1652938A
Application number: US663509A
Authority: US
Inventors: Edward M Hewlett
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1923-09-18
Filing date: 1923-09-18
Publication date: 1927-12-13
Anticipated expiration: 1944-12-13

Description

Dec. E3? 1927. LGSZ 938 v E. M. HEWLETT INDUCTANCE COI L Filed Sept. 18, 1923 5 Sheets-Sheet 1 'UNIF r'u/e VLCOP Edward MH ew Lett,

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Dec., m, w27.

3 Sheets-Sheet 2 E. M. HEWLETT INDUCTANCE COIL Filed Sept. 18, 1925 iii l J zo E. M. HEWLETT INDUCTANCE COIL Filed Sept. 18, 1925 3 Sheets-Sheet 3 i ma? u N l'- W l W25 f n HN www ll E' Patented Dec. 13, 1927.

UNITED STATES PATENT oFFlcE. l

EDWARD M. HEWLTT, OF SCHENECTADY, NEW YORK, ASSIGNOR T GENERAL .TRIO COMPANY, (A CORPORATION OF NEWVYORK.

ELEC- INDUCTANGE (10113.l

Application led September 18, 1928. Serial. No. 663,509.

of my invention is to provide an elicient means for spacing and insulating` from one another the separate turns of the coil.

The novel features which'I believe to be characteristic of my invention are set forth with particularity in the appended claims.

Theinvention itself, however, both as to its organization and method of operation, to-A gether with further objects and advantages thereof will best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. 1 is a perspective-of a coil constructed in accordance with my invention; Fig. 2 is a plan view thereof; Fig. 3 is an elevation of a portion of a coil illustrating certain of the structural features thereof; Fig. 4 is a detail showing a modification in the construction of the coil; and Figs. 5 and 6 arev perspectives, taken at different angles, of the spacing and insulating devices. i

As shown in the drawings, vthe coil is built up'around six supporting posts 1 to 6 of insulating material uniformly spaced around the circumference' of a circle. The lower ends of these posts are provided with bases 7 which may be secured to any suitable foundation by means of bolts 8. These posts may comprise porcelain tubes 9 the lower ends of which are surrounded by cylindrical'porcelain insulators 10. The posts are held in their desired'parallel yposition by means of metal bands 11 each of which is provided with an insulating joint 12, in order that these bands shall not form short circuited secondary windings, for the coil. The two lower bands 11 are secured to the posts by means of clamping rods 13 and spacing members 14 of insulating material. The clamping rods 13 are provided with "insignaling systems sulating bushings for insulating them from the bands 11 and thus preventing the formation of a closed circuit in which induced currents may flow. In the construction of the coil support metal parts are used only where necessary to obtain the desired strength as the use of metal parts in the coil support tends to increase thelosses of the co1 Y The coil which I have illustrated is of the multl-layer type, each layer consisting of four turns. The turns of the coil are all supported upon,A insulators 15 and are all heldin spaced .relation to one another. rlhe insulators 15 are of lsubstantially triangular shape having conductor holders in which retaining grooves 16 are formed secured to two sides thereof. The third side of each insulator 1.5 lis provided with a groove 17 for receiving the porcelain tubes 9. Each insulator is also provided withv an opening 18 for receiving a clamping band 19. Each end of the clamping' band 19 is attached .to a yoke 20, which surrounds a projection 21 on the spacing block 22. The clamping ff' bands are thereby made discontinuous so that they donot form closed circuits in which induced currents may flow. The upa per'bands 11 are secured to the posts l1 to 6 by means of the rods 23 which are secured i" to the ends of clamping bands 19.

In winding the conductor 24 uponfthe supporting structure, the conductor is first wound upon the inner groove of the top series of insulators starting at point 25 and then' progressively outward until the last groove of the top series is reached at 26. The conductor is then carried down to the outer groove on the lower side of the next insulator at 27 and wound progressively in- @E ward until the last groove on the lower side of the top series of' insulators is reached. The conductor is then carried down to the inner'top groove of the next insulator of the second series and progressively outward as 100 on the top series. and sol on until the end of the coil is reached at the inner groove on the lower side of one of the insulators of the lowest series.

When the coil is wound in this way it will 105 be noted that.the maximum potential developed in the coil during operation between the two outer turns of adjacent layers carried by any insulator will be the potential developed in a single turn of the conductor u@ while the maximum potential developed bctween the two inner turns of adjacent layers carried by any insulator will be the potential developed in eight turns. By making the insulators of triangular form the spacing between the two inner turns carried by each insulator is made enough greater than the spacing' between the two outer turns to take care of the greater potential developed between the two inner turns. The distributed capacity o f thecoil is also reduced by this expedient. Similarly the spacing between the outer turns on the lower side of one series of insulators and the top of. the next or adjacent series below is made greater than the spacing between the inner turns to take care of the increased potential.

It will also be observed that the conductor retaining grooves on the lower side of the insulators are in staggered relation to the grooves on the upper side so that the turns of the conductor retained on the lower side of the insulators are not directly below the turns retained on the upper side of the linsulators. This expedient increases the spacing between turns and also reduces the tendency to the formation of partial short circuits of the turns which might be caused by the formation of icicles between turns due to water dripping from one turn down onto an adjacent turn directly below it.

In the construction of the insulators l5, three important conditions are taken into consideration; first, a large creepage surface over the insulator is desirable'between the diierent conductors; second, a portion of this creepage surface should be so arranged that it will at all times remain substantially dry; third, means should be .provided for preventing the formation of large streams of water which will flow over the insulator and between adjacent turns of the conductor.

by supporting the conductor holders in which the upper grooves 16 are formed on a central rib 28, which is of less thickness than the length of the grooves, and also by the provision of a barrier .29, which is interposed between the two sets of grooves, and which in turn is wider than the length of these grooves. A substantially horizontal rib 30 also provides a secondary barrier between the inner grooves of the top and bottom series. Each of thel grooves is also provided with a central projection 31 so arranged that the conductor will be in contact only with this central projection and will not be in contact with the grooves throughout their whole length.

The second condition is taken care of byv reason of the fact that the under portion of the upper set of' conductorholders is not directly exposed to the elements and the under side of the barrier 29 .is not directly The first of these conditions -is providedA exposed. Grooves 32 are also referably provided on the lower side of tiie barrier 29, which prevent water from creeping along 'the lower side of the barrier to the central rib 28. The barrier 29 is provided with depressions 33, which serve to collect water falling on the surface of the insulator and cause it to be broken up into separate streams. The possibility of water forming in one large stream and running ofi the surface of the insulator and forming a short circuit between conductors is thereby prevented. The depressions are so located that the water dropping from the edge of the barrier will not fall directly upon the conductors resting in the lower series of grooves.

If desired, additional protection may be furnished by means of a barrier 34, as shown in Fig. 4, which is interposed between superimposed insulators. This barrier is provided with a plurality of transverse grooves in order to subdivide as much as possible the stream of water which may iiow over the insulators. n

For convenience in shipment the bands 11 instead of being formed from one continuous strip of metal may be formed in sections, which are bolted together at points 35, as indicated in Fig. 2.

What I claim as new and desire to 'securel by Letters Patent of the United States, is

1; An insulator having a set of conductor retaining grooves formed thereon and arranged in a substantially horizontal plane, and a second set of grooves formed thereon and arranged in a plane which intersects the plane of the first set.

2. An insulator of substantially triangular form having a plurality of conductor retaining grooves formed on two sides thereon and the third side thereof being'adapted to be readilyv attached to a support.

3. .An insulator of substantially triangular form having a plurality of conductor retaining grooves formed on two sides thereof, the third side of which is formed to partially embrace a support.

4. An insulator of substantially triangular form having a lurality of conductor retaining grooves thereof and the grooves in one side being individuell out of vertical alignment with correspondlng grooves in the other side.

5. An inductance coil made up of a plurality of layers each layer comprising a plurality of turns,'said turns being all held out of contact with one another by a plurality of insulators each of which supports at least one turn of two layers.

6. An inductance coil made up of a plurality of layers, each layer comprising a plurality of turns, said turns being all held out of contact with one another by a plurality of horizontally mounted insulators,

ormed on two sides' each of which supports at least one turn of two layers.

7. An inductance coil made up of a plurality of layers each layer comprising a plurality of turns, said turns being all held out of contact with one another by a plurality A of insulators each of which support two layers, the oppositely disposed turns ot each pair of adjacent layers thus supported heilig spaced at di'erent distances from one another than any other air.

8. An inductance coll made up ot a plurality of layers, each layer comprising a plurality of turns, said turns being all held out of contact with one another by a plurality of insulators which support each layer in such a way that the air of turns in adj acent layers between which the highest potential diiference is developed during operation is separated b a greater .dista-nce than the other pairs o turns.

9. A multi-layer inductance coil comprising a plurality of circumferentially arranged posts, each of which has secured thereto a plurality of spaced supporting insulators, each of which insulators serves to support and hold in spaced relation the turns of two layers of the coil.

10. An inductance coil comprising a plu-` rality of circumferentially arranged posts each of which has secured thereto a plurality of supporting insulators of substantiallytriangular form having conductor retaining grooves formed on two sides thereof. 11. An inductance coil comprising a plurality of circumferentially arranged posts each of which-has secured thereto a plurality of supporting insulators of substantially triangular form having vconductor retaining grooves formed on two sides thereof one of which lies in a substantially horizontal plane.

12. An inductance coil comprising a plurality of circumferentially arranged posts each of 'which has secured thereto a plurality of supporting insulators of substantially triangular form having conductor retaining grooves formed on two sidesthereof, said grooves servin to retain the individual turns of the coil in spaced relation to one another.

13. An inductance coil comprising a plur'ality of circumferentially arranged posts each of which has secured thereto a plurality of supporting insulators of substantially triangular form having conductor retaining grooves formed on two sides thereofa said grooves serving to retain the indivldual turns of the coil in spaced relation to one another, and the turns of the coil being' so arranged that' adjacent turns between'which the highest potential difference is developed during operation are separated by a greater distance than other adjacent turns.

14. An insulator of"substantiallytriangular form having a lplurality of conductor retaining grooves formed ontwo sides thereof, the third side thereof being ada ted to be readily' attached to a support, an having a' lrctaining r grooves formed on two sides thereof, the third side thereof being adapted to be readily attached to a support, and having a barrier interposed between the grooves on the two sides, said barrier being of greater width than the length of the grooves.

17. An insulator having a set of conductor l retaining grooves formed thereon and arranged in a substantially horizontal plane, a second set of grooves formed thereon and arranged in a plane intersecting the plane ofthe first set, and a barrier interposed between the two sets of-grooves, sai-d barrier being of greater width than the length of the grooves.

18. An insulator comprising a central rib, a plurality of conductor holders having conductor retaining grooves secured to opposite edges of said rib and a barrier extending from opposite sides of said rib and interposed between the conductor holders which are secured to the opposite edges.

19. An insulator comprising a central rib and a plurality of conductor holders having conductor retaining' grooves secured to opposite edges of said "rib, said conductor holders being of materially greater length than the thickness of the rib.

20. An insulator comprising a central rib, a plurality of conductor holders having conductor retaining grooves secured vto o posite edges of said rib, said conductor hol ers being of materially greater length than the thickness of the rib, and a barrier extendingfrom opposite sides of said rib and interposed between the conductor holders` which are secured to the opposite edges.

' 21. An insulator comprising a central rib, a plurality of conductor holders having conductor retaining grooves secured'to opposite edges of said rib, said conductor holders be'- ing of materially greater length than the thickness of the rib, and a barrier extending from opposite sides of said rib andinterposed between the conductor holders which are secured, to the opposite edges, said barrier being of greater width than the length of the conductor| holders.

In witnessr whereof, I have hereunto set my hand this 17th day of September 1923.

'EDWARD M. HEWLETT.