US2280861A - Transformer distributing system - Google Patents

Description

April 28, 1942. H. E. soMEs TRANSFORMER DISTRIBUTING SYSTEM Original Filed Aug. 20, 1936 5 Sheets-Sheet 1 INVENTORL Howe RD E .SoMEs A TTORNE Y.

April 28, 1942. H E, SO ES 2,280,861

TRANSFORMER DISTRIBUTING SYSTEM I Original Filed Aug. 20, 1936 5 Sheets-Sheet 2 INVENTOR: ,Howalzofisowes A TTORNE Y.

April 28, 1942. H. E. SOMES 2,280,861

TRANSFORMER DISTRIBUTING SYSTEM Original Filed Aug. 20, 1936 5 Sheets-Sheet 3 Z I II- 4:2 INVENTOR.

HOWQRDE. SOMES.

WW ATTORNEY.

April 28, 1942. H. E. SOMES 2,280,861

TRANSFORMER DISTRIBUTING SYSTEM Original. Filed Aug. 20, 1936 5 Sheets-Sheet 4 INVENTOR. HOWQRDE. Sowas.

W44,- ATTORNEY.

April 28, 1942. H. E. SOMES TRANSFORMER DISTRIBUTING SYSTEM Original Filed Aug. 20, 1936' 5 Sheets-Sheet 5 EIGB INVENTOR. HQWQRDE .SOMES ATTORNEY.

Patented Aprt28,l942

rasssroam nrsramo-rmc srs'rssr Original application August 96.929. Divided and tilt 21, 1938, Serial No. 180,194

flclaims.

The present invention relates in general to alternating current transformers and more particularly to' a transformer arrangement of the sliding core type. and is a division of my copending application Serial No. 96,929 filed Au ust 20, 1838, for Transformer distributing system now Pat. No. 2,223,902, Dec. 3, 1940.

An important object of the invention is the provision of a sliding core transformer capable of use as a combined power transformer and switch, especially adapted to the distribution and control of heavy, high frequency currents such as in electrical heating, especially inductive heating. In this connection, certain improvements are effected which make possible the application of electro-magnetic switching to power circuits in such manner that the act of switching will not produce substantial disturbances in the electrical supply circuit. Transient phenomena are minimixed Another object of the invention is to make possible the use of extremely short leads between the transformer secondary winding and a movable work circuit by moving the secondary circuit with the work circuit and without having to move the primary circuit or other parts of the transformer.

Another object is to combine the feature of electro-magnetic switching with the feature of having the secondary winding in fixed relation with the work circuit for movement therewith, in such cooperative relation that the movement of the work circuit into and out of working position will effect the proper movement of the transformer secondary into and out of operative relation with the transformer primary.

An ancillary object is the provision of a transformer structure having i y efilcient magnetic field elements, and one in which the windings may be readily changed without disturbing the assembly of the'individual magnetic field elements. This feature makes for further advantage and economy in that either the inner or outer winding may readily be replaced, one without disturbing the other, thus obviating the necessity for the use of taps for varying the effective winding, and eliminating losses due to idle coils, or high-reluctance gaps in the magnetic circuit caused by tap leads entering the winding space.

While the invention finds particular usefulness in the supply of low voltage, heavy current to inductive heating, where the heating element must be moved in relation to the work or to and from the work with minimum length of leads Bombetroi 20, 1936, Serial No. ap January between the transformer secondary and the heating element, and its structural features are particularly adaptable to a transformer of a sliding core type. the various novel structural features involved are applicable to the construction of transformers in which the primary and secondary elements are fixed in relation to each other with marked improvements in compactness, lightness, and efilciency.

Various other objects and advantages of the invention will become apparent upon perusal of the following specification and the drawings s companying the same.

In the drawings:

Fig.1isanaxialcrosssectionalviewofmy improved transformer used in connection with a heat treating device, the transformer being shown in idle position.

Fig. 2 is a similar view showing the transformer in operating position.

Fig. 3 is a top plan view of a transformer shown in Figs. 1 and 2.

Fig. 4 is a fragmentary sectional view taken on the line l4 of Fig. l and on an enlarged scale.

Fig. 5 is a schematic mechanical and circuit diagram showing the apparatus .of Figs. 1 and 2 in idle position.

Fig. 6 is a diagram similar to Fig. 5 showing the apparatus in working position.

Fig. 7 is a side view partly in section of a modified form in which the extension core is separable from the main core of the primary element.

Fig. 8 is a similar view showing the separate extension core arrangement applied to the tapered extension core type as used in Figs. 1 and 2.

Fig. 9 is a similar view of a modified form capable of use with mechanical switching.

Figure 10 is a circuit diagram illustrating one use of the transformer.

Referring more particularly to the drawings and first to Figs. 1 to 4, the primary transformer element I has slidably mounted therein the secondary transformer element 2, which latter carries in fixed relation therewith the work circuit or load circuit which in the present instance is an inductive heating coil 3 of the type shown and described in my co-pending application Serial No. 50,829, filed November 21, 1935 on Inductive heater.

The primary element consists essentially of a primary winding mounted within the inner surface of a primary magnetic element of general cylindrical form. The secondary element 2 comprises essentially the secondary winding 8 moimtbetween the coil and laminations.

ed within the outer surface of a secondary magnetic element, 1 also of general cylindrical form. The work coil 3 is directly connected to the terminals of the secondary winding through short leads 8-9. The secondary element 2 also carries an extension or auxiliary core l arranged to be positioned within and as part of the magnetic circuit of the primary element 1 when the secondary element is in the uppermost position with the secondary coil out of operative relation with the primary coil as in Fig. 1.

A frame member II in the form of a bracket supported ring or short cylinder supports and holds the various parts of the primary element in assembled relation as a unit. Within the frame II, are mounted an annular series of radially arranged laminations l2 of suitable magnetic material, taper ground so that their surfaces will lie along radial planes. A thick tapered block 2|! of insulating material, such as micarta," is interposed between laminations to provide space for the exit of the conductors I8-l9. Suitable insulation 22 is provided between the convolutions of the coil 4 and between the coil and the laminations. It is preferable also to provide a covering of insulation 23 for the radially inwardly facing surface of the primary coil 4, which not only serves the function of insulating the coil electrically but tends to prevent the collection of moisture on the surface of the winding where the cooling fluid used in the coil is below atmospheric temperature.

The secondary element 2 is assembled as a unit on the central supporting arbor 24 of non-magnetic material on which is mounted the circular series of laminations 28 of suitable magnetic material held in position between the upper removable clamping ring 26 and the lower fixed clamping ring 25, the latter being integral with the supporting arbor 24. These clamping rings are provided with annular wedge ribs 21 which engage complementary notches in the laminations 28. These laminations are also taper ground so that their surfaces will lie in planes radial to the axis of the supporting arbor and thus fit snugly together to form a substantially solid mass of laminated material. A key 29 engaging the upper end of the arbor 24 and the upper clamping ring 26, holds the upper clamping ring in proper angular relation to the arbor and the integral lower clamping ring, the upper clamping ring being held and adjusted axially by long cap screws or bolts 30 extending between the upper and lower clamping rings. Recessed portions 32 in the laminations 28 form an annular recess in the outer surface of the whole cylindrical secondary magnetic element core I in which is mounted the secondary winding 6 formed from a tubular conductor, the convolutions of the coil being insulated from each other and from the laminations by suitable insulating material 33 arranged between the convolutions of the coil and The terminals of the secondary coil 6 are extended radially inwardly through the laminations by means of electrical and fluid conducting leads 34 and '35.

- Because in the present instance the conductors in the secondary winding 6 are arranged as a multiple group of four, the leads 3435 take form of manifold connections each effecting electrical and fluid connections with a group (for example three or four) of the tubular conductors. The leads 34 and 35 are suitably positioned in relation to and insulated from the laminations by a wedge-shaped block of insulating material 4! Cir interposed between the radial laminations and through which block the leads extend. Within the hollow cylindrical, magnetic element I the leads 34 and effect electrical and fluid 'connections with the tubular conductors 36 and 31 respectively, which latter are sheathed in insulating tubes as indicated at 2|, to insulate them from the upper and lower clamping rings through which they pass, and in which they are held in position by means of top and bottom clamp nuts 38-39 and insulating washers 40-42. Connection is made between the tubular conductors 3B3l and the short leads 89 by means of suitable tubular clamping elements 43.

The work coil 3 is mounted in fixed relation with the secondary element 2 by means of the tubular arbor extension 44 (also of non-magnetic metal) to which the coil 3 is fixedly secured, the arbor extension 44 being secured to the main arbor 24 by threaded engagement therewith as shown in Figs. 1 and 2. The main supporting arbor 24 is itself supported together with the work coil 3 as a unit by the tubular supporting rod 45 secured to the arbor 24 by threaded engagement therewith and arranged to movably support the arbor in a suitable manner for 10wering and raising the secondary element 2 into and out of operative relation with the primary element l.

The laminations 28 of the secondary core extension III are conically recessed in their outer edges as at 28a to space this extension divergently away from the primary. A displacement ring 46 of insulating material, preferably of micarta is arranged to fill in this space and complete the outer cylindrical surface of the secondary element 2. This ring 46 acts as a guide and bearing for the secondary element 2 by engagement with the axially extended, inner cylindrical surface of the lower clamping ring i4 of the primary element. An operating cylinder 45a for supporting rod 45 provides an upper bearing for the sliding secondary element 2.

The article to be worked upon, here indicated as the hub element 41 of an automobile wheel, is so positioned and spaced in relation to the apparatus that the lowering of the work circuit or work coil 3 into operative relation with such work 41 will move the secondary element 2 from the position shown in Fig. 1 down into the position shown in Fig. 2 with the primary and secondary elements in transformer relation. To insure accurate position of the work a suitable work holder 48 is provided which is held in fixed relation to the transformer mounting through the base frame 49. To assist in guiding coil 3 into proper working position, a tubular pilot arbor 50 is provided which extends through the tubular supporting elements 24, 44 and 45 in sliding relation thereto, and is itself of tubular form and provided at its lower ends with perforations 5| through which a suitable quenching fluid may be projected to the surface of the work 41. The end of the pilot tube 50 is capped by a pilot head 53 which engages in the tapered bore of the small end of the hub. The head 53 is fluted on its surface to permit the drainage of quenching fluid through the hub opening where a liquid is used for the quenching fluid. Any suitable means (not shown) may be used to project the pilot arbor and cooling head 5| into and out of relation to the work. All this is shown and claimed in a copending applica- In operation having particular reference to 8,8,801 3 i'igaiandzthepartsbeinginthe positionof exoeptringlharerigidlyconnectedtogether. Fig. 1', and the combined pilot and spray tube The movement upwardly of element I takes coils lobeingraisedtothedottedlinepositionshown landloutofjuxtapositionandthsrebycuts in Fig. 1, the work 41 in the form, in this case. of! the supply of energy to the coil I. of a hub is loaded upon the machine, the hub 6 Immediately after the movement of the coil inder not shown, but lying above cylinder "a, the pilot and spray tube II is forced downwardly until its piloting end II effects piloting, centering and aligning engagement with the small tapered bore of the small end of the hub. This action aids in holdingthe work 41 upon the support I, though other and yet stronger clamping means (not shown because not a part of the invention claimed herein) may be used and preferably are used to firmly hold the work in place. The engaging end II of. pilot tube II, however, is centered in position with respect to the work piece 41, lying precisely upon the axis of the bore of the barrel of the work piece. At this time no water spray' comes from the spray head II. Now, however, the work and the pilot tube II and the sliding transformer comprising primary and secondary elements I and I are concentrically arranged on the same central axis.

Thereupon, with the parts occupying a relation as shown in Fig. 1, power is applied to cylinder 45a to carry the secondary element 2 of the transformer downwardly and with it the working coil I. The parts sliding upon and with respect to the pilot tube II are now bottomed in the small bore of the hub 41. Work coil I enters the barrel of the hub to occupy the position shown in Fig. 2. Simultaneously the secondary coil I of the transformer enters the primary coil 4 and occupies a position in which full secondary voltage is in use in the secondary circuit comprehending secondary coil I and work coil I in series through connections I, II, II, I1, I and I. The full power of the transformer l2 is applied through the work coil I to the work piece 41.

Incident to the lowering to the secondary ele- I out of the work piece 41, quenching water is delivered to the combined pilot and spray tube II and spraying water II is applied to the heated interior of the work piece 41 to strongly quench the work and thereby harden this interior surface.

A of these movements take place in but a fraction of a second or but a very few seconds, say for example 1 to 4 seconds. However, even for this short time, the work coil I is guarded against undue reduction in reactance on being withdrawn from the surrounding low reluctance medium of the hub, by its simultaneous movement into the medium of low reluctance fur nished by the magnetic ring II. The dwell of the work coil I in the work piece is from 1 to 2 seconds in the instance of the automobile wheel hubillustrated as a work piece. The cylinder ",therefore, operates to project the secondary tube downwardly and to raise it at a relatively high velocity. It is in these movements that the transformer of my invention exercises its switching function. When the secondary element 2 is in the raised position as shown in Fig. l, coil I is substantially entirely without the magnetic field of the primary coil 4 of the transformer. In its place is the extension II of the core of the secondary. This extension Ill being composed of laminations of magnetic material, when juxtaposed in such position to coil 4 as shown in Fig. 1, serves to choke the primary coil 4 and thereby to cut down the amount of power consumed by this coil. This choking effect is so nearly complete as to cut the current down to near the ment 2, the magnetic sleeve has also been lowered. Before the coil I reaches the bottom, the end of the magnetic sleeve 55 reaches the reentrant end 56 of the work piece 41 where it fills up the recess and comes to a stop against its outer end through the shoulder a. However, further movement of work coil I proceeds unhampered by reason of the fact that the ring I! is carried by'spring 51 which yields and permits .the work coil II to be projected beyond it. When the coil I receives its power due to juxtaposition of windings 4 and I of the transformer, the magnetic flux created thereby about coil I threads through the core of coil I, through the work and through the lower end "a of the ring 55 thereby insuring a magnetic circuit of very considerable improved eiliciency. This it does by diminishing reluctance of the circuit by eliminating air gaps which might exist through the reentrant portion 56 of the work piece.

The work having been heated to the required degree in such fraction of time as may have been chosen, the pressure in cylinder to is reversed, whereupon coll I is raised once again to the position shown in Fig. l, and with it, after it has men raised a certain degree, is carried upwardly once more the ring II and the spring 51. Simultaneously with this movement upwardly the secondary element 2 of the transformer is moved upwardly, for all of these parts,

value of the magnetizing current of the transformer but of suflicient magnitude relative to the capacitance in th primary circuit to prevent undue change in power factor. In other words, the magnetic material of the extension II takes the place of the magnetic material of the secondary coil 6, but is not itself provided with any work coil, and thereby the more effectively cuts down the power. The moment that the secondary 2 is lowered, the extension II as shown in Fig. 2, is projected out of the magnetic field of the primary element 1 and the magnetic core of the secondary 6 takes its place, the secondary being.

off from coil 6 and coil 4 again choked by the work circuit of the transformer i-I.

extension Ill.

The introduction of an extended air gap, divergent downwardly. between the primary core and the secondary core extension serves in connection with the utilization of capacity on in the circuit of the primary 4 (see Figs. 1, 5 and 6) to modify the power factor of the secondary or This it does by increasing the reluctance of the primary of the transformer when the transformer parts are in the cut-oil! position shown in Fig. 1. The divergence of the gap downwardly introduces a gradual widening of the gap, as the work coil I is pulled out of the work whereby to eifect gradual compensation for the change in power factor, commensurate with the change in power factor occasioned by the withdrawal of the work coil I. The relations .of the parts upon entrance of the work coil into the work piece, are diagrammed in Fig- 6, while their relations on withdrawal from the work piece are diagrammed in Fig. 5. The utilization of magnetic switching by the transformer as thus carried out, avoids entirely the need for open circuit switching in connection either with the primary of the transformer or the secondary.

The tapered extension I for the secondary element finds its greatest use where a condenser is connected across the terminals of the primary transformer winding for the power factor correction, in which case the air gap provided by the tapered core extension operatesto produce sufficient lagging quadrature current in the primary circuit to compensate for the leading quadrature current taken by the condenser to thus maintain the power factor substantially constant. In Fig. 7 is shown a modification in which a different form of core for the secondary element 2 is employed. This difference resides in the form of the extension i0. Here the extension i0 is comprised of laminations 6| separate from the laminations 28 of the secondary element 2 and of the full radial depth of the laminations 28, the outer surface 62 being cylindrical even as are those of the laminations 28, the insulating ring 46 of the form of Figs. 1 and 2 being omitted. This organization is achieved by providing an intermediate clamping ring 63 between the lower clamping ring and the upper clamping ring 26 and provided with annular ribs 64 engaging respectively the laminations 28 and the laminations Si in their adjacent ends. Such a form of the extension (H is to be desired in combination with the capacitance 65 placed directly across the terminals of the secondary work circuit. These terminals, designated respectively 66 and 61 are the flexible metallic leads to the upper ends of the water circulating conduits and conductors 36--31. The combination of this particular form of extension In with a capacity 65 directly in the work circuit renders unnecessary the use of a capacity 60 in the primary circuit and its accompanying large air gap in the extension H) as shown in Fig. 1. This is for the reason that when the capacity 60 is removed from the primary circuit and put upon the secondary, troubles in the supply circuit occasioned by removal of the closed circuit secondary winding with a capacitance still across the terminals of the primary winding no longer exist, and the primary of the transformer takes its least power when its magnetic circuit is possessed of the least reluctance, that is to say, when the extension laminations 6| enter most intimately into juxtaposition with the laminations 5, and the permeability of the magnetic elements is greatest. In other words, when the capacity is put in substantial part or entirely in the work circuit, there is no leading current trouble for which to compensate through the use of the graduated air gap introduced by tapering the extension l0 and providing it with an insulating ring 46.

The idea of separately supporting the laminations 28 of the secondary coil 6 and those 6| of the extension Hi may be embodied if desired in the form of the invention shown in Figs. 1 and 2 on the other hand may be used as may be desired.

In such combination varying divisions of capacitance may be made as between the primary of the switching transformer and the secondary, and accompanying them varying degrees of air gap and taperings of the extension ll, dependent upon the peculiar condition which it may be .desired to meet. However, I have found that the two arrangements disclosed respectively in Figs. 1 and 2 on the one hand and Fig. 7 on the other hand, constitute means suflicient to effectively provide against variations in the supply line and the variations of power factor in the secondary line occasioned by the switching operation of the transformer.

In Fig. 9 is shown a transformer comprised of the primary and secondary elements I2 which has no core extension Ill providing only for relative movement of the coils 4 and 6 and their magnetic cores. Such an arrangement is peculiarly advantageous in that when the extension I0 is omitted, the work coil 3 may be arranged nearer to the secondary with a very considerable reductionin the length of the leads 89 of the secondary circuit, thereby reducing the reactance. Opening the circuit of the primary coil 4 by means of a circuit breaker 58, provided as shown in Fig. 10, provides against any flow of current into primary coil 4 or its capacitance 80. In any event, circuit breaker 58 would be put between the primary coil with its capacity correction and the line. Any desired means not shown may be used for coordinating relation of the circuit breaker and the sliding transformer. In the usual operation, secondary element 2 would be moved into juxtaposition with the primary element I as shown in Fig. 9 in order to inject the work coil 3 into proper relation to the work piece and then the circuit, breaker would be closed. Upon the completion of the heating, the circuit breaker would be opened and then the transformer operated to remove the secondary 6 from the primary 4. Or, if desired, with the proper use of capacitance, initial switching of the power would be done by the transformer, coil 6 being removed upwardly from coil 4 and then the circuit breaker 58 operated. In either event, we have the advantage of a closed coupled relation between the work coil 3 and the secondary 6 without flexible leads for current and water.

Of course, there will occur to the initiated many other modifications of my invention which do not deter in any wise from its true spirit. These others, as well as those I have just described, should be comprehended by the annexed claims.

What I claim is:

1. A transformer comprising an inner annular core member composed of substantially radial laminations to form a continuous transverse annular section, a winding about said core terminating short of at least one end of the core, an outer annular shell core composed of substantially radial laminations to form a continuous transverse ring section, a winding wound within the walls of the outer annular shell terminating short of at least one end of the shell, said inner core being arranged within the outer shell with the windings in juxtaposition and overlapping, and said inner core and shell having their laminations extended radially over at least one end of the coils toward each other to substantially encase the overlapping coils said core member and its winding thereabout, and said outer shell core and its winding within being relatively movable with respect to one another substantially on their common axes.

2. A transformer comprising an inner core member of annular transverse section composed of substantially radial laminations in contact throughout their opposed surfaces to form a body of substantially solid laminated material, a winding on said inner core member terminating short of at least one end of the'core member, an outer annular shell member composed of substantially 10 radial laminations in contact throughout their opposed surfaces to form a body of substantially solid laminated material, a winding within the shell member terminating short of at least one end of the shell member, said inner core member and annular shell having their laminations extended radially toward each other over at least one end of their respective windings and means for moving the inner core member relative to said shell member.

3. A transformer comprising an annular inner core element, a winding on said inner core element terminating short of at least one end of the core element, an outer magnetic annular shell element, a winding wound within the walls of the outer annular shell element and terminating short of at least one end of the shell element, said core element and said shell element beingslidably movable wlthrespect to one another and at least one of the ends of said core and shell elements radially over the ends of said coils toward each other to form the magnetic circuit of a shell-type tramformer, having concentric magnetic circuit elements of substantially continuous transverse ring section, one of said coreand shell elements having an integral axial extension adapted to form a second shell type transformer magnetic circuit embracing-but one said core and shell elements having an integral axial extension adapted to form a second shell type transformer magnetic circuit embracing but one of the windings when one winding is moved axially out of relation with the other and said axial extension having a varying cross-section adapted to provide a gradually increasing air gap as relative motion between the elements forms said second shell circuit.

5. A transformer comprisingan annular inner core element, a winding on said inner core element terminating short of at least one end of the core element, an outer magnetic annular shell element, a winding wound within the walls of the outer annular shell element and terminating short of at least one end of the shell element, said core element and said shell element being slidably movable with respect to one another and at least one of the ends of said core and shell elements extending radially over the ends of said coils toward each other to form the magnetic circuit of a shell-type transformer, having concentric magnetic circuit elements of continuous transverse ring section, one of said core and shell elements having an integral axial extension adapted to form a second shell type transformer magnetic circuit embracing but one of the windings when one winding is moved axially out of relation with the other and said axial extension having a cross-section providing an increased air gap when positioned to form said second shell magnetic circuit.

6. A transformer comprising an annular inner core element, a winding on said inner core element terminating short of at least one end of the core element, an outer magnetic annular shell element, a winding wound within the walls of the outer annular-shell element and terminating short of at least one end of the shell element, said core element and said shell element being slidably movable with respect to one another, at least one end of said core and shell elements extending radially over the ends of said coils toward each other to form a shell-type transformer, having concentric magnetic circuit elements or continuous transverse ring section, one of said core and shell elements having an integral axial extension adapted to form a second shell type transformer circuit embracing but one of the windings when one winding is moved axially out of relation with the other and said axial extension having a cross-section providing an increased air gap when positioned to form said' second shell magnetic circuit.

HOWARD E. SOMES.

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