US2637012A

US2637012A - Inductor of dynamo machine

Info

Publication number: US2637012A
Authority: US
Publication date: 1953-04-28
Anticipated expiration: 1970-04-28

Description

April 28, 1953 J. M. PESTARINI 2,637,012

INDUCTOR OF DYNAMO MACHINE Filed Nov. 20, 1946 F l G. 5 o 6 F l G. 4 INVENTOR Joseph M eyfarizzi Zak 2 5. W

ATTORNEY Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE INDUCTOR 0F DYNAMO MACHINE Joseph Maximus Pestarini, Staten Island, N. Y. Application November 20, 1946, Serial No. 710,977 3 Claims. (craze-27) This invention relates to compensated dynamos.

In compensated dynamo machines, the field inductor must include a compensating winding for creating ampere turns in the direction of the armature ampere turns and being proportional to and in opposed relation thereto, and a second winding for creating a flux necessary to induce the electromotive force of the dynamo between the brushes thereof. The compensating Winding has its magnetic axis coincident with the axis of the armature ampere turns, which may be referred to as the main magnetic direction. The second winding has its magnetic axis generally displaced 90 electrical degrees from the main magnetic direction, and may be referred to as the transverse magnetic direction.

The copper losses and copper weight of a compensated dynamo are thus higher than for a non-compensated machine. Further, the compensating winding is more complex than the field winding which makes the cost of a compensated machine quite high. However a compensated machine provides for a better distribution of the voltage between the commutator segments and a more stable voltage independent of the load, as well as more stable operation during a rapid variation in load.

An object of this invention is to provide means for reducing the weight and losses of the windings of a compensated dynamo. This is accomplished by means of an improved winding having the combined characteristics of a compensating winding and a field winding. Such winding may be in endless form, similar to the armature winding, and is traversed in the main magnetic direction by acurrent proportional to the armature current, for compensating the armature ampere turns. The winding is also traversed by another current in the transverse magnetic direction which is supplied by a separate source, for creating the necessary ampere turns for the main magnetic field. The two currents move in the same direction along one segment of the circuit and move in opposite directions along another segment of the same circuit. With such arrangement, the copper losses are materially reduced.

Another object of this invention is to provide in a machine of the character described. an endless winding madeup of a plurality of interconnected coils, each coil being mounted on a polar segment and the coils being arran ed in polygonal form. Such winding is also adapted to be traversed'by a pair of currents, as previously described.

A further object of this invention is to provide in a machine of the character described, a winding which is arranged to be energized by amplifier metadynes in a manner to provide the ampere turns equal to the resultant ampere turns normally provided by the two windings of a conventional compensated machine.

Still another object of this invention is to provide an amplifier metadyne which creates a current for traversing the endless winding in the main magnetic direction, such current being proportional to the armature current, whereby the winding is not subjected to the main current of the machine and may therefore require relatively light insulation.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

In the drawings, Fig. 1 shows a compensated dynamo in schematic form; Fig. 2 shows a modification thereof; Fig. 3 shows a further modification thereof, with a pair of dynamos; Fig. 4 shows a further modification, wherein the endless winding is independent of the armature; and Fig. 5 shows still a further arrangement embodying the invention.

The metadyne, hereinafter mentioned, is generally described in Patents 2,055,240: 1,987, 11?

2,038,380; 2,049,389 and 2,079,465. The amp1i= fier metadyne is described in Patent 2,112,604.

In Fig. 1, is shown a compensated dynamo, wherein I represents the armature; 2 represents the compensating winding and 3 represents the field winding. The armature has a pair of brushes 0, c with brush a connected to an input terminal 6. Input terminal 5 is connected to winding 2 at a point diametrically opposite to a point 4 thereon, which is connected to brush- 0 on the armature winding I. The terminals of winding S-are indicated at l, 8. 'Thus, the input currents at terminal 6 enters the armature winding through brush a, leaves at brush 0, to enter the compensating winding at point 4 leaving at terminal 5.

In a conventional compensated dynamo, the compensating winding generally provides a single electrical path. According to the instant invention, a winding is provided in endless form, somewhat like an armature winding of a direct current machine. The direction of the ampere turns created by a current traversing such a winding, which enters the winding from a given point and leaves at a diametrically opposite point, is determined by the diameter connecting such points. Thus, by modifying the location of such points, one may modify the direction of the ampere'turns created by the winding. Fig. 1,

therefore, shows a special compensated dynamo embodying the invention.

The endless winding 2, may, according to the invention be also used for creating the ampere turns of the field winding 3, thus eliminating the need for such separate field winding. To this end, as shown in Fig. 2, a current may be supplied to winding 2 at two diametrically opposite points 1, 8, so that the flux will have a path such as the flux path created by winding 3, as shown in Fig. 1, and will be in the transverse magnetic direction.

In Fig. 2, an auxiliary source is provided for supplying current to the winding 2 at points i, 8, in the form of an amplifier metadyne 9, whose output brushes 2), d are connected to the winding 2 at points 1, 8, the primary brushes a, c of the metadyne 9, being short circuited. The input current traverses the winding 2 from point."

4 and the point diametrically opposite thereto, by input terminals-5, 6, as previously described. The amplifier metadyne 9 includes a stator winding H] which is adapted to be independently energized, a stator winding I! connected across the brushes a, c of armature winding 1, and a stator winding [2 which is traversed by a current proportional to'the armature current, derived from a shunt 13. It is understood that any other suitable source of controlled direct current may be supplied to Winding 2 at points I, 8. Thus, the volt ampere characteristic of the dynamo machine may be given any desired form, such as is obtained in a conventional dynamo by means of an independently excited field winding, a series field winding and a shunt field Winding. i

The endless stator Winding 2, as shownin Figs. 1, 2, may be replaced by a winding comprising four or more interconnected coils, each coil being interlinked with a stator-polar segment, as shown in Fig. 3. If it is desired to incline the magnetic axis of the ampere turns created by the armature current traversing the winding in order to influence the electromotive force between the dynamo brushes a, 0, one may modify the relative resistance of the four branches of the endless circuit in accordance with the settings of a Wheatstone Bridge.

With the arrangement of the magnetic body of the endless winding in more than two polar segments, there is provided free interpole spaces.

In accordance with the instant invention, auxiliary brushes may be located on the axis of these new free interpole spaces. Thus, there is obtained a condition .of'balanced currents in a machine having a plurality of cycles and with a plurality of machines operating in parallel, by interconnecting the homologous auxiliary brushes. Thus, the dynamos may function as dynamo electric machines'of the metadyne type, such as is more fully described in application Ser. No. 701,794, filed October 7, 1946.

As shown in Fig. 3, a pair of similar dynamos la, 30 are coupled together. The brushes a of the dynamos are connected together and to input'terminal 6. The brushes 1), d of the dynamos are connected respectively in parallel. The dynamo la comprises an endless stator winding which consists of interconnected coils 2!, 22, 23 and 24, each of the coils being interlinked with a polar segment of the machine. Brush of the machine is connected to the coils at point 4 While input terminal 5 is connected to the coils at point diametrically opposite point 4. Field control current is supplied tothe coils through terminals 1, 8, from a suitable source, as previously described. The dynamo 30 is also provided with an endless winding similar to that of dynamo la and having connections similar thereto and including the terminals 1, 8 for supplying current to the winding in the transverse magnetic direction.

The endless winding of a dynamo embodying the invention, may be separately energized in the two magnetic directions, as shown in Fig. 4. Here, a pair of amplifier metadynes 9, I4, each having its brushes a, 0 short circuited, are arranged to create ampere turns in the transverse and main magnetic directions, respectively. Thus, metadyne 9 includes an independently energized stator winding ID, a stator winding H shunt connected across brushes a, c of the dynamo l and a stator winding l2 which is energized with a current proportional to the arma-' ture current, by means of a shunt l3 interposed in the armature circuit. The metadyne [4 includes a stator winding l5 which is connected across the shunt l3 and carries a current also proportional to the armature current.

The output of metadyne 9, through its brushes b, d, is connected to terminals 1, 8 on winding 2, while the output of metadyne l4, through its brushes 2), d, is connected to terminals 5a, 4 of winding 2. The input current for the dynamo is supplied to brushes a, 0 thereof, through

terminals

5, 6. It will be apparent that the winding 2 carries none of the armature current and with control currents only, traversing the same, the insulation of the winding may be materially reduced. It is understood that the end-' less winding 2 may be made up of four or more interconnected coils, each coil being interlinked with a polar segment, as previously described.

A dynamo having four similar, equidistant polar segments, may have a single coil wound on each segment, the opposed coils being displaced electrical degrees from each other and interconnected to provide an independent circuit adapted to be energized by an amplifier metadyne. Thus, as shown in Fig. 5, dynamo includes

separate windings

22, 23, the respectively opposed and interconnected windings, being omitted. The magnetic axes of

windings

22, 23 are displaced 180 electrical degrees from each other and are disposed at an angle of 45 electrical degrees with respect to' the main and transverse magnetic directions of the dynamo.

The winding 22 is supplied'with current by metadyne M and the winding 23 is supplied with current by metadyne '9. The stator windings l2, l5 of the respective metadynes, are supplied with current proportional to the'armature current, by means of shunt [3. The stator windings I I, I6 of the respective metadynes, are shunt connected across the brushes 0., c of the dynamo. The stator windings it, ll of the respective metadynes, are independently excited.

With the arrangement shown in Fig. 5, the direction and magnitude of the resultant amis to be understood that all matter herein set forth or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. A compensated direct current dynamo machine comprising an armature and a single, continuous, endless stator winding, said stator winding being provided with four terminals per cycle disposed euuiangularly to each other, means for supplyirr said stator winding with a current proportional to the armature current traversing said stator winding through two of said terminals disposed at L80 electrical degrees from one another, means for supplying said stator with a current traversing said stator winding through the other two terminals whereby to create a magnetic field that induces an electromotive force between the brushes of the armature of said dynamo machine, one of said current plying means comprising an amplifier Lietadyne a for supplying said second mentioned current, said ampli metadyne including a plurality of stator windings for controlling the intensity of the generated current, one of said metadyne windings being connected across the term: a of the dynamo machine, another of said in dyne windings being supplied with cunent iro; an independent source and another or" s metadyne windings being traversed a current proportional to the armature current of said dynamo machine.

2. A compensated direct current dynamo machine comprising an armature and a single, continuous, closed in its self stator winding, stator Winding being provided with four terminals per cycle disposed equiangulariy to each other, means for supplying said stator winding with a current proportional to the armature current traversing said stator winding through two of said terminals disposed at 180 electrical degrees from one another, means for supplying said stator winding with a current traversing said stator winding through the other two torminals whereby to create a magnetic field that induces an electromotive force between the brushes of the armature of said dynamo ma chine, said first mentioned current supplying means comprising an amplifier metadyne, said metadyne including a stator winding controlling the intensity of the generated current and being traversed by a current proportional to the armature current of said dynamo machine, said second mentioned current supplying means comprising an amplifier metadyne, said last mentioned metadyne including a plurality of stator windings controlling the intensity of the gen erated current, one of said metadyne windings heing shunt excited across the terminals of the dynamo machine, another of said metadyne windings being supplied with current from an independent source and another of said metadyne windings being traversed by a current proportional to the armature current or" said dynarno machine.

3. A compensated direct current dynamo machine comprising an armature, a field inductor with four polar segments per cycle, and an endless single stator winding, composed of single coils, each of said coils being interlinked with one of said polar segments, the said coils being connected in series with one another; the said stator winding being provided with four terminals per cycle, each terminal being located on the connections between two consecutive coils; means for supplying said single stator winding with a current proportional to the armature current traversing the said single stator winding through two of the said terminals located 180 electrical degrees from one another; means for supplying said stator winding with another currer" traversing the said single stator winding through the other two of said terminals whereto create the magnetic field inducing the electroinotive force in the armature between brushes; the first mentioned current supplying means comprising an amplifier metadyne, said metadyne comprising a stator winding in circuit with said dynamo armature and traversed by a current proportional to the armature current or the said dynamo; said second mentioned current supplying means comprising another amplifier metadyne, said last mentioned metadyne including a plurality of stator windings, one of said last mentioned windings being a winding shunt connected across the armature of terminals of the said dynamo, another of said last mentioned windings being adapted to be energized by an independent source of current, and a third of said last mentioned windings in circuit with said dynamo armature and traversed by a current proportional to the armature current of the said dynamo.

JOSEPH MAXIMUS PESTARINI.

References (Jilted in the file of this patent UNITED STATES PATENTS Number Name Date 925,607 Stanley June 22, 1909 1,351,036 Hellmund et a1. Aug. 31, 1920 1,401,996 Lundell June 3, 1922