US2417880A - High-frequency generator - Google Patents

Description

March 25, 1947. NHLBURN AL 2,417,880

HIGH FREQUENCY GENERATOR Filed Aug. 5, 1944 2 Sheets-Sheet l BY [fir/per h- 52/777242 MM 4% Alfarneg March 1947- G. MILBURN ET AL 2,417,880

HIGH FREQUENCY GENERATOR Filed Aug. 5, 1944 2 Sheets-Sheet 2 INVENTORS, 460, on] l schnqckg am lhforne Patented Mar. 25, 1947 HIGH-FREQUENCY GENERATOR Guy Milburn and Walter H. Schnack,

. Evansville, Ind.

Application August 5131944, Serial No. 548,226

This invention relates to an electrical generator and has as its primary object the generation of currents of high frequencies by a comparatively small structure, It has no moving coils or windings, and the frequency or cycles per second are not dependent upon circumferentially spaced windings. Furthermore, alternating curgenerated with a constant direction magnetic flux, Fundamentally, the invention involves a laterally reciprocating magnetic field as opposed to a rotary field.

A further important object of the invention is to provide an extremely simple structure, not only for initial production, but in reassembly in the event some part may become damaged.

These and other objects and advantages of the invention will become apparent to those versed in the art in the following description, with reference being made to the accompanying drawings, in which:

Fig. 1 is a view in central, vertical, longitudinal section through a generator embodying the invention; I

Fig. 2, a view in transverse vertical section on the line 2--2 in Fig. 1;

Fig. 3, a diagrammatic view of elements for one magnetic flux circuit; and

Fig. 4, a similar view of elements the next succeeding circuit.

Lik characters of reference indicate like parts throughout the several views in the drawings.

Within a generally cylindrical housing I is mounted at each end stator core ring spacers II and I2, herein shown as held in position by the housing ends I3 and I4, which are secured to the housing i 0 by any suitable means, such as by the screws I5.

Held by these spacers II and I2 are core rings I6 and I1, each having a like number of equidistant spaced apart slots entering from its peripheral edge. Entered within these slots, are the reduced ends I8 of alternating groups of core laminations I9 and 20, and these ends I8 are secured firmly in place by an encircling band 2I on the ring I6 and 22 on the ring IT. The bands 2I and 22 are held within the rings II and I2 and the laminations remain stationary.

All of the core laminations I9 and are identical in size and contour, but are reversed, end for end, in alternate groups around the rings I6 and Il. Referring to Fig. 3, the lamination I9 is cut away from its inner edge top to provide, in the present showing, a rectangular slot 23 to leave an upturned leg 24 at the right end with the end I8 outside thereof and extending there- 6 Claims. (Cl. 121-252) from. Then, the lamination I9 has a slot 25 cut therein toward its other end to leave a leg 28 intervening between the slots 23 and 25 of substantially the same width and height of the leg 24. The slot 25, at its left side, has a marginal edge 2'! sloping diagonally upwardly and outwardly to the left edge of the lamination I9, from which the end I8 extends. Preferably, the upper end of the edge 2] terminates below the common line across the top edges of the legs 26 and 24.

Each group of laminations I9 and 20 may consist of from one to any desired number of laminations, depending upon the permissable diameter of the rings I6 and I1 and the frequency and wattage to be produced. In any event, one group of laminations will be positioned as indicated in Figs. 1 and 3, and then the next a j g p around the rings I5 and I1 will be reversed, end for end, as represented in Fig. 4.

Now with those alternately positioned laminations, there will be available a circumferential path around through all the groups to receive therein, a secondary winding 28 in the nature of a doughnut coil, so proportioned as to fit snugly within that path to have its sides in substantial contact with the left edge of the leg 26 of the lamination group l9 and the right edge of the leg 24 of the next lamination group 20, and so on entirely around the spaced lamination groups. In the group I9, there will be no contact by the laminations on left vertical side of the winding 28, due to the receding edge 21 of each lamination.

A central path across and through the lamination groups will be afforded and an exciting winding 29 is placed therein and therearound, to have the right side edge of the leg 26 in group I9 along the left side of the winding and no contact by the group I9 laminations on the right, Figs. 1 and 3, and reversely,-as to group 2|), to have the then left edge of the leg 26 in contact with the right side of the winding 29, and with no contact therewith on the left-a space being left between the windings 28 and 29, Fig. 4.

Furthermore, a third path is provided across and through the lamination groups I9 and 20' toward their right ends, to receive therein and therearound, the second secondary winding 30, whereby in group I9, the left side edge of the leg 24, Figs. 1 and 3, will be in contact with the right side of the winding 30, with a space between it and the exciter winding 29, while in group 20, the then right edge of the leg 26 will contact the left side of the winding 30, Fig. 4, and the edge 21 will be receding from the winding 30.

The two housing ends l3 and I4 are provided with any suitable bearings, such as ball bearings 3|, to revolubly carry a shaft 42 axially of the cylinder defined by the inner edges of the lamination legs 24 and 23 and the inner sides of the windings 23, 29, and 30 which are substantially in transverse alignment therewith. Carried by this shaft 42 in any suitable manner; are a pinrality of bars 32, preferably laminated, substantially parallel and spaced apart one from another to have their outer edges at a common radial distance from the axis of the shaft 42. In the present showing, these bars 32, for ease in assembly, are made in two sections, one abutting end to end with the other, and those sections have their ends received in slots of outer discs 33, 34, and inner discs 35, 36 fixed to turn with the shaft 42. The bar sections are retained in their respective disc slots by means of bands 31, 33 and 39, 44 compressively engaging over reduced height ends of the sections. The overall diameter of the circle defined by the peripheral edges of the bars is such as to bring those edges in close proximity with and just clear the ends of the legs 24 and 23 when the shaft 42 is turned by any suitable outside source of power.

While the number of lamination groups in the stator and also the number of bars in the rotor may vary, depending upon the frequency desired in connection with the rotor speed, there is a fixed ratio, in that there willbe one-half as many bars 32 as there are stator lamination groups or laminated bars. For example, the drawing shows forty-eight stator bars while the rotor has twenty-four bars, giving a half cycle between adjacent stator bars. The stator formed as above described, is a two pole stator regardless of the rotor speed and the number of stator bars. It is desirable to provide ventilation through the rotor and stator, and the drawing shows one form wherein, the housing ends i3 and I4 are provided with holes 43 and 44, and the rotor discs 33 and 34 are provided with holes 45 and 46. The stator bars or lamination groups [9 and 20 are spaced from the housing I for free circulation therearound and therebetween. Other than the rotor bars 32, and the laminations l9 and 20, much of the generator may be made of non-ferrous materials.

The operation of the generator is best explained in reference to Figs. 3 and 4. The winding 29 is excited or energized by direct current from any suitable outside source, as in alternating current generators. In Fig. 3, the bar 32 closes (except for the slight air gaps therebetween) an iron magnetic fiux path or core between the legs 24 and 28 that extend from their under interconnecting part of the bar or lamination i9, the fiux set up by the winding 29, traveling as suggested by the arrow, when the bar 32 closes that core upon rotation of the rotor, to induce a current in one direction in the winding 30. Then, when the bar 32 opens that core with bar i9 to travel on to bar 20, Fig. 4, a reverse direction current is induced in the winding 30, to give the alternating current fiow through one cycle.

When the bar 32 travels on to bridge between the legs 24 and 26 in Fig. 4, the other winding 28 is included within that substantially closed core, and hence current is induced in that winding 28 of alternate fiow with the rapid opening and closing of the core. Thus it is to be seen that the magnetic fiux reciprocates in effect, first through a closed transformer core to one side of the exciter winding and then through one to the 4 other side. The windings 23. 24. and 34 have suitable leads 41, 44, 49, 50 and ll, 52 respectively carried therefrom out through the housing ll, Fig. 2.

While we have herein shown and described our invention in the one precise form, it is obvious that variations in mechanical design may be made without departing from the spirit of the invention, and we therefore do not desire-t0 be limited to that precise form beyond the limita-' tions of the following claims.

We claim:

1. For generating high frequency currents, a plurality of closely spaced, fixed transformer core sections arranged to have terminal leg ends define an internal cylindrical opening thereacross; a circular exciter winding fixed between said legs; a secondary circular winding spaced to one side of the exciter winding fixed in relation to said pieces; a second circular, secondary winding spaced from the other side of said exciter winding and fixed in relation to said pieces; said pieces extending across all of said windings; legs on said pieces arranged to extend therefrom inwardly, alternately to have therebetween said exciter winding and said first secondary winding; and said exciter winding and said secondary winding; an armature rotatable within said cylindrical opening; and bars spaced apart around said armature arranged to tend to close a magnetic fiux path therethrough alternately about said secondary windings upon rotation of the armature.

2, In a high frequency generator, a pair of spaced apart, axially aligned doughnut windings; an exciter doughnut winding axially aligned with the first windings; a plurality of iron core members spaced circumferentially around and extending transversely across said windings; legs alternately extending from adjacent core members to encompass laterally said exciter winding and one of said first windings and the exciter winding and the other of the first windings; and means to revolubly carry spaced apart iron bars across the inner terminal ends of said core mew bers linking together said legs of each core member; whereby a variable magnetic field of constant direction, reciprocating laterally of direction of travel of said means, is set up; said bars being half in number of said core members.

3. In a high frequency generator, a stator having a plurality of magnetic fiux carryin members extending transversely thereacross and spaced apart therearound, an exciter winding extending circumferentially around and across said members; a secondary winding extending circumferentially around and across said members, and legs on said members encompassing outer sides of said windings; and an armature mounted axially of said stator and having spaced apart bars extending thereacross as peripheral portions thereof substantially parallel to the armature axis, said bars being suificiently long to bridge said legs upon travelling therepast; a second secondary winding extending around said members; said members further having on alternate ones, legs encompassing said exciter winding and said second secondary winding.

4. An electric generator comprising an exciting current carrying winding; 9, pair of spaced apart generated current carrying windings, between and from which said exciting winding is spaced; magnetic flux circuit members arranged for shifting one group in relation to another group thereof to alternately route the fiux in a continuous direction, first around said exciter winding and one of said generated current windings and, second, around the exciter winding and the other of said generated current windings; and means shifting one of said groups of flux circuit members in relation to the oth r group.

5. An electric generator comprising an exciting current carrying winding; a pair of spaced apart generated current windings, between and from which said exciting winding is spaced; magnetic flux circuit members arranged for shifting one group in relation to another group thereof to alternately route the flux in a continuous direction, first, around said exciter winding and one of said generated current windings, and second, around the exciter winding and the other of said generated current windings; means for shifting one of said groups of flux circuit members in relation to the other group; the flux members of one group comprising substantially straight bars, and the members of the other group being divided into a series of sub-groups wherein pole pieces alternately extend from bars across the three windings to be in one sub-group on the outer side of one of the generated current windings and on the opposite side of the exciter winding, and in the other group, on the outer side onlyof the other generated current winding and the opposite side said exciter winding and one of said generated current windings, and second, around the exciter winding and the other of said generated current windings; means for shifting one of said groups of flux members in relation to the other group; the flux members of said one group comprising substantially straight bars, and the members of the other group being divided into a series of bars with pole pieces alternately on the outer sides only of said generated current windings and the opposite side therefrom of said exciter winding; said straight bars being of sufficient length to extend across both of said generated current windings, whereby the pole piece on the outer side of one of said generated windings is bridged with the pole piece on the opposite side of the exciter winding, and upon shifting, the straight bar successively bridges the pole piece on the outside of the other generated current winding with the pole piece on the opposite side of the exciter winding, thereby shuttling the magnetic field with constant direction flow from side to side of the exciter windin to alternately include one of said generated windings therein.

GUY MILBURN. WALTER H. vSCHNACKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Hoover et al Feb. 27, 1945 Number

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