US967361A - Alternating-current motor. - Google Patents

Description

V. A. FYNN.

ALTBBNATING CURRENT MOTOR.

ArPLIu'rIol FILED JAN. 29, 1909.

967,361 Patented Aug. 16,1910.

4 SHEETS-MEET 1.

181;? Fig-2? I Fig.3. f

V. A. FYNN.

ALTERNATING CURRENT MOTOR.

APPLIOATION FILED JAN. 29, 1909.

967,361. Patented Aug. 16, 1910.

4 SHEETS-SHEET 2.

V. A. FYNN. ALTEBNATING CURRENT MOTOR;

APPLICATION FILED JAN. 29, 1909. 967,361. Patented Aug. 16,1910. I 4 SHEEN-$112111 3.

Egg. 1 5.

Fig.11.

V. A. FYNN.

. ALTERNATING CURRENT MOTOR.

APPLICATION FILED JAN. 29, 1909.

Patented Aug. 16, 1910.

4 8HEETS-SHEET 4.

Y Fig.1 4.

UNITED STATES PATENT OFFICE.

VALERIE ALFRED FYNN, OF LONDON, ENGLAND.

ALTERNATING-CURRENT moron.

Specification of Letters Patent.

Patented Aug. 16, 1910.

To all whom it may concern: Y

Be it known that I, VALERE ALFRED FYNN, a subject of the King of England, residing at London, England, have invented a certain new and useful Alternating-Current Motor,

of which the following is such a full, clear, and exact description as will enable any one skilled in the art to which it appertains to make and use the same, reference being had to the accompaiging drawings, forming part of this speci catlon.

and to reduce to a minimum those changes inconnections of the motor, which are absotutely necessary after the latter has reached lts normal speed; to, make the transition -5 from the starting to the running condition 2 without a material, reduction in the magnitude of the torque and quite indepen ent of the operator or of any switching devices, be these operated automatically or by hand; to provide improved means for compensating the motor after the running condition has been attained; to improve the commutation of the machine; to prevent racing,

' p and to fully utilize all the copper on the induced member for the production of a useful torque, thusincreasing the efficiency of the machine.

, It has heretofore been impossible to start I motors of the type referred to, with a powerful torque an a reasonably small current consumption, as compared to the current consumption at full load, without opening. the winding closed on itself at the moment of starting, or without impairing the efliciency and the characteristlc properties of said winding under normal running conditions. If the winding closed on itself is opened during the starting period, a device must be provided for closing that winding when a certain speed has been reached. If this device is not operated in time, the motor is liable to race; in any case such a device, especially if automatic, is costly and liable to get out of order. If the starting is accomplished by impairing the efli'ciency of the winding closed on itself, for instance by placing it in slots placed at some distance from the air-gap, or byinserting unduly large impedances of any kind, then the speed of such a motor under load is subject to material variations, and its output is greatly reduced.

By winding closed on itself, as used herein, is meant a winding of an desired description containing any desire amount of impedance, 2'. e. ohmic resistance, reactance or capacity but permanently closed on itself alon at least one axis per pole pair and in sue a manner that currents may be induced therein b the main inducing winding. Thus a 3 p ase winding is closed on itself along 3 axes per pole air, whereas amember, whether the latter revolves or not.

Now according to this invention, motors of the type herein referred to may be started with a powerful torque per ampere without any possibility of racing and while making the fullest possible use of the w nding closed on itself under normal working conditions, thus retaining the well known and advantageous load characteristics of the induction motor. In the motors herein described, the. commuted winding and the winding closed on itself are preferably placed in the same slots and as near to the air-gap as possible. The windlng closed on itself is, therefore, fully eflectlve under normal running conditions and the motor will 0 erate at a nearly constant speed even if t e commuted winding be switched out of circuit after the motor has reached its full speed. Since in this improved motor, the mutual induction between the commuted winding and the winding closed on itself is very high, then thelatter will be effective in reducing or preventing sparking either at starting or during normal operation. In addition, I make use of the commuted winding for the purpose of improving the power factor and the efliciency of the machine under normal operating conditions.

In the accompanying drawings, which illustrate a motor made in accordance 'with my invention, and some of the possible modilications thereof, Figs. 1, 2, 3 are diagrammatic views explanatory of the principles of operation of the motor, Fig. 1 shows a simple form of the new motor, Fig. 5 is a phase diagram relating to Fig. 4, and Fig. 6 a graphical representation of the torque conditions obtained in Fig. 4. Fig. 7 is a diagrammatic view of my motor in series connection and making use of a series transformer at starting with means for deriving a compensating voltage from the transformer under running conditions. Fig. 8

' shows an arrangement for deriving the comensating voltage from an auxiliary wind mg on the inducing member, Fig. 9 shows a series arrangement without: compensating devices, Fig. 10 shows a series arrangement with means for deriving the compensating voltage from the main inducing winding, Fig. 11 shows a shunt arrangement together with devices for adjusting the phase of the current in the commuted winding, Fig. 12 is a shunt arrangement with means for deriving the starting current and the compensating voltage from the main inducing winding, Fig. 13 is a shunt arrangement wherein the startingcurrent is derived from the main inducing winding, and the compensating voltage from an auxiliary windmg disposed on the inducing member, Fig. 14 is an arrangement in which the commuted winding is notonly in series, but also in shunt relation to the line at starting, Fig. 15 shows the use of a neutralizing winding closed on itself. Fig. 16 discloses means whereby all the available space and all the copper on the inducing member can be fully utilized under running conditions Figs. 17 .and 18 indicate modified arrangements of brushes on the commutator, and Fig. 19

shows impedances permanently inserted in the circuit or" the winding closed on itself.

Like marks of reference refer to similarparts in the several views of the drawings.

Referring to Figs. 1, 2, 3, 4, 5 and 6, 20'

represents the mam'inducmg' winding supplied from mains 21, and 22' is a winding closed on itself carried on the induced member, here, the rotor. It is known that'a motor such as shown in Fig. 1 will not start from rest. The reason being that the axis of the only magnetic fiux in; the motor threading both stator and rotor, coincides with the only current axis in the induced nember, bothaxes fall in the direction Y Y in Fig. 1. If the current axisin the induced member can be displaced from the direction Y Y for instance, so as to coinside with X X, while preserving the flux alongY Y, whlch flux 1s due to the winding 20, then a useful torque will be developed. In order to secure this condition I first of all provide the induced member of V the machine with an additional winding 23,

connected to a commutator inthe usual way,

and on which rest the brushes 24, as shown with that of the main inducing windin ,"a

current derivedfrom the mains. In- 3 this is achieved by connecting the mam inducing winding 20 in series with the commuted winding 23, and the mains 21 by way of the brushes 24. "Although a motor con stituted as shown in Fig. 3 will start from rest, yet it will develop but a small torque per am ere. The winding 22 which is closed on itse f, will now also be acted upon inductivel by winding 23. Ampere turns of practice 1y equal magnitude and nearly opposite direction will, therefore, be set up in winding 22, thus effectively neutralizing any torque which windin 23 might otherwise have produced in comunction with the flux alon Y Y. The torque which sets the motor s own in Fig. 3 in motion, is due to the interaction of the current induced in 22 by 20, withthe small flux along X X due to the vectorial difference between the ampere turns in 23 and 22 along that axis. in order to secure a larger torque per ampere, I secondly. provide a winding 30 disposed on the inducing member, and adapted to pro-' duce a magnetization alon an axis displaced from that of the main in ucing winding 20 by preferably something like 180/n degrees,

where n stands for-\ the number of poles.

This arrangement is shown in Fig. 4. For ease of identification, I will refer to thiswinding 30 as the gneutralizin winding, for it 1s designed to control t e relation between the ampere turns in 23 and 22 along X.X'. This neutralizing winding is to be connected in series relation with the commuted windin sion in'series relation is intended throughout the specification and. claims to mean that the circuit comprising said neutralizing and commuted windings is so constituted.

and that those windings are so connected that the current which passes the one always, bears a constant ratio to the current passing the other as long as the connections remain unchanged. I have discovered that it is possible to so proportion and dis ose this neutralizin winding and to so ad iust the phase'relation between the currents in 30 and in 23 as to greatly reduce, or even entirei cancel the ampere turns in 22 along x :2".

For this purpose it is necessary to take into account the great difference in the leakage conditions existing between 23 and 22 and between 30 and 22, and select the phase, magnitude and space osition. of the.

either directly or with the lnterposition o a transformer. The expresampere turns in 30 according gcfi This props osition is clearly materially rent from that usually met with and where one winding on one member. of a machine.is to be interaction 0 neutralized by another winding on another member of the machine,

In carrying out my invention and according to the results desired, the stage of the starting performance, the mode of connectlon, and the constants of the machine, I

may cause the neutralizin winding to produce a magnetization, eit ercoinciding in direction, or opposed to that roduced by 23, thus either increasing or re ucing the ampere turns in 22 along X X and as com-.

that the connections'are those shown in Fig.

4, then the operation of my improved motor may be made clear as follows.

.If the winding closed on itself has a low ohmic drop as compared with its reactance voltage (or self-induction) then the current i. due to 6, induced therein alon Y Y" by 20 will la by close on 80 deg. be ind 0 as shown in ig. 5. Where P is supposed to be the pressure atthe terminals of 20, F the flux of mutual induction along Y Y, 2', the magnetizing current in 20, and i, the total current in 20. Since 20 and 23 are connected in series, then the same current 2', flows through; all three windings, and since the windin closed on itself has no ampere turns along X X, then the ampere turns in 23, due'to -2',, can produce a torque with F,. From Fig. 5 it is seen that the eflective torque component 252', of i, is nearly equal to i the conditions which have been established inraccordance with this invention are, therefore, very favorable, and the motor will start with'a owerful torque Z, due 'to the f the flux alon Y Y and of re turns on the induce X' As the speed increases this torque Z diminishes as approximately indicated in Fig.6.- The reason'for'this is that the phase di erence-between i, and P, as well asthe magnitude of i, diminish with increasing speed, and that thesediminutions are only partlycounter-balanced by. an increase, of but as thespeedincreases vthe winding closed on itselfsets up a .fiux F alon X X which-flux is displaced in phase-by a at 90- deg. with regard to-F and 'themotor then developsanother torque Z, (see Fig. 6), due to I the interaction of- F, with the rotor ampereturns along Y'Y' due to the current i,

ln-the winding closed on itself. The resultant torque of the motor is, therefore, Z,- and. it is seen that. it keeps mcreasmguntrl closeto the s nchronous speed, which .isindicated by the otted line X, and then rapidlydrops to zero. In this manner the motor is. automatically converted intoan ordinary selfmember along excited shunt induction motor. It has been assumed that the am ere turns in 22 were practicall eliminate This can be fully achieved y adjusting the phase relation between the current passing through 23 and that passing through 30. The means adopted for that purpose in Fig. 4 consist of a resistance 52 connected in parallel to 30. When the motor has reached a suflicient speed switch 53 can be opened thus discon-. necting the resistance 52, or the machine maybe operated without altering any of the connections. In many cases good results may be secured Without adjusting the phase of the current in 23 and 30. In such cases 52 and 53 need not be used and there is no necessity whatsoever to make any changes in the connections after the motor has been connected to the mains, but if refinements are to be introduced, then certain alterations may be made.

When the ampere turns in 22 are to be zero the aim is to so adjust the phase of fhe current in 23 with relation to that of the current in 30 that the E. M. F. induced in 22 by 23 be exactly op osed in phase to that induced in 22 by 30. hen these E. M. Fs. are not only of exactly opposite phase but also of equal magnitude, then the ampere turns in 22 along X X will be m'l. This phase relation may be adjusted in any known manner, for instance by connecting an impe- I dance in parallel either to 30 or to 23. \Vhen this impedance is to be connected in parallel to 30, then a resistance or a capacity will preferably be used; when it is to be connected in parallel to 23 then a reactance is generally preferable. I may also connect winding 23 in shunt relation to 20, or to the mains 21, instead of in series relation with them. In this case the phase difference be tween F and the current through 23 will, as a rule be greater-for otherwise equal con-' ditions, than that between i, and F in Fig. 5, but the mode of operation will be quite Similar. In order to bring the current through 23 more into phase with F,, I place a reactance or choking coil in the circuit of 23 for the parallel connection, and connect it in parallel to 20 for the series connection. With the help of these explanations it will be readil understood how the improved motor wil operate when winding 30 does not entirely eliminate the am re turns in 22 along X X. For one t ing the reactance of the circuit containing 23'and 30 a will be increased in such cases, thus reducin the total current taken by the motor. therefore, make use of such an arrangement to reduce the current, taken by the motor when first connected to the mains, to as small an amount as may be desired, gradually allowing the current to increase by changing the number of turns of the neutralizing winding or the direction of the a cancer I magnetization produced by it, or by both means. In a modification I placethe circuit containing the winding 23 both in series and in shunt relation to the mains. I have stated that the neutralizing winding may be in conductive or inductive relation to the commuted winding. The conductive rela- 21 are connected to the main inducing windratio series transformer '25. 'is-connected to part of the primary of 25 through switch 28 and conductor 27. This ing 20 through the primary of the variable One main 21 primary is connected to 20 through conductor 26. The connection is such that the volts per turn in the main inducing winding can be varied, thus allowing the ma nitude of F, to be regulated even when the terminal Volta e is kept constant. The other main 21 is irectly connected to 20. An adj ustable reactance 34 is connected in parallel to 20 for the purpose of bringing the current in 23 into closer phase coincidence with F The commuted winding 23 is conductively connected to the neutralizing winding 30 by way of one-brush 2a and the conductor 4;) carrying a'movable contact adapted to vary the number of turns in 30. This circuit is fed in series relation with 20 by way of the secondary of the series transformer 25; one end of the secondary of 25 is connected to one of the brushes 24, the other is connected to a point of 30 through the conductor 48,

u the switch 31 and the conductor 46.

- along three axes per The latter carries a movable contact b means of which the transformation ratio 0 25 can be varied. An adjustable resistance 52 is connected in parallel to 30 by way of switch 53, for the purpose of adjusting the phase relation between the current throu h 23 and through 30. The winding 22 closed on itself is shown by -'way of example as being closed ole pair. Another set of brushes disposed a ong the axis of 20 are in contact with the commuted winding, their circuit is, however, left open at starting.

The motor is started by gradually reducing the number of"-"efl:'ective turns in 30 to Zero, reversm the direction of the magnetization by 30, "and then increasing the "number of efi'ective turns in 30. This is accomplished in Fig. 7 by aduallymoving the contact attached to conductor 49 from left to right. When the motor has reached a'sufiicient speed, the reactance 34 and the compensating resistance 52 are disconnected. The movable contact on conductor 26 is placed in transformer 25 which did dut as a series y transformer at starting, in parallel with the line and the movable contact on conductor 46 is so adjusted as to compensate the motor to the desired extent by means of the vol:

tage derived from the shunt transformer 25 and impressed on the commuted winding 23. Finally switch 51 is closed, thusallowin at least part of the working current to ow through the commuted winding, whereby all the copper on the induced member is utilized to the fullest possible extent.

In Fig. 8 T have shown an operative combination in which the compensation is secured by means of an additional winding 35, disposed on the inducing axially with 20. The winding closed on itself is here shown as being closed along 8 axes per pole pair, and is supposed to beef the form known as the squirrel cage. All

switches are shown in the starting position.

Winding 30 is adapted to produceamagnetization of opposite direction to that produced by winding23 and be so adjusted that the squirrel cage carries no current component along the axis of 30. When a sufficient speed has been reached, switch 28 is closed thus short circuiting the primary of the series transformer 25. Switch 31 is opened, thus disconnecting the neutralizing winding and switch 36 is closed, whereby a compensating E. M. F. of suitable phaseand magnitude is impressed on 23 from 35 for the purpose of compensating the motor to any desired extent.

In the operative combination shown in Fig. 9, the series transformer is dispensed with. When the motor has reached a suflicient speed, switch 31 is thrown into contact with conductor 32, thus cutting windings 30 and 23 out of circuit, and throwing the full line-voltage on 20. When operating the machine in this last named combination, the current taken by the motor passes throu h the commuted winding along the motor fiedd axis,.and lagging a little in phase with re- 0 spect to the exciting ciirrent generated in t e winding closed on, f by rotation in the flux F, it tends to"""-iinprove the power factor of the motor. -In the arran ment' shown in Fig. 4, and which has alrea y been discussed, no changes at all are made in the connections after the motor has reached its normal speed.

In the arrangement shown in Fi 10, the

. M. F. is derived into contact with conductor 2% 70 member 00- 90 "om the main inducing winding 20by means of connection 37, instead of making use of a.separate stator winding, or an outside transformer. When the motor has reached a sufficient speed, winding 30 is cut out of circuit bythrowing switch 31 into contact with conductor 29, and the machine is compensated by closing switch 36. K

In the operative combination illustrated by Fig. 11, the current conducted through the commuted winding at starting is derived in parallel from the line by means of the shunt transformer 25. The line is directly connected to winding 20, provision being made for varying the volt-s per turn in this winding. One end of the secondary winding of the shunt transformer 25 is connected to the one brush 24 by means of the conductor 29 carrying a movable contact adapted to vary the ratio of 25.; the other end of this secondary is connected to the other brush 24 through switch 31, the adjustable reactance .40, conductor 49, and winding 30. Gonduc toi' 49 is provided with a movable contact, by means of which the number of effective turns in 30 can be varied. A reactance 54 is connected in parallel with the commuted winding 23 by way of switch 53 for the purpose of adjusting the phase relation between the current through 23 and the current through 30. \Vhen a sutlicient speed has been reaclied,'switch 31 is thrown into contact with conductor 32, whereby the reactance and the neutralizing winding are cut out of circuit and switch 53 is opened. The voltage derived from 25 can now be adjusted to secure the desired compensation.

In the'arrangement shown in Fig. 12, the shunt transformer of Fig. 11 is combined with the motor itself, the winding '20 thereof being made use of for that purpose. The line is connected directly to part only of winding 20. The circuit including the commuted winding is fed from one terminal of 20 through switch 31, winding 30, impedance 40, brushes 24 to conductor 29, and back to some portion of 20. The movable contact attached to 29 makes it possible to vary the voltage impressed on the circuit comprising the commuted winding, and since the line voltage is only impressed on part of 20, then the voltage impressed on 23 can be raised above the line voltage. \Vhen the motor has reached a sufiicient speed, switch 31 is thrown into contact with conductor 32, thus disconnecting 30, and the voltage derived from 20 is so adjusted as to secure the desired degree of compensation.

The operative combination shown in Fig. 13 shows an arrangement by means of which a definite voltage, derived from 20 by means of the conductor 29, is impressed at starting on 'the circuit comprising the commuted winding 23 and the impedance 10 and another voltage, suitable for compensating purcontact with conductor 32, thus effecting the change described.

Fig. 14 shows one arrangement, the switches standing in the starting position in which the circuit comprising the commuted winding 23 is connected in shunt as well as in series relation to the line. Winding 20 is connected to line 21 through the primary of the variable ratio series auto-transfornier The secondary of this transformer is connected in series with 23 by meansof conductor 29 and brushes 24, and also in series with 30. The circuit comprising 23 is connected in parallel to the line 21. When a sufficient spccd has been reached switch 28 is closed, thus sliort-circuiting the primary of 25. Switch 31 is thrown into contact with conductor 32. thus cutting 30 out of.

circuit, and switch 36 is thrown into contact with conductor 46. thus impressing on the commuted winding a suitable compensating volt-age derived from 20.

In Fig. 15 is shown one arrangement in which the neutralizing winding is in inductive relation to the commuted Winding, and where the commuted winding is not only in series, but also in shunt relation to the line. The main inducing winding 20 and the commuted winding 23 are connected in series across the line 21. .\n E. M. F. derived from the secondary of the variable ratio shunt. transformer 25 connected to the line by the conductors 39, is in addition impressed on 23. At starting. the neutralizing winding 30 is short-circuitcd by means of switch 31. \Vhen a sufficient speed has been reached, switch 31 is opened. and the movable contact attached to conductor is adjusted to secure the desired degree of compensation.-

In the examples heretofore described, the neutralizing winding was mostly left out of circuit in normal operation. The space occupicd by that winding and the copper used in it were, therefore, wasted.

Fig. 16 shows an o erative combination in which all the available winding space and all the copper on the inducing member is fully utilized, while deriving the compensating E. M. F. from a winding disposed on the inducing member. At starting switch 36 open, when the motor has reached a sutiicient speed, winding 30 is left in circuit, and switch 36 is closed. To get the best results it is desirable to dispose the compensating a sutlicient speed has been use of in this modified position.

winding 35 along the 'axis of the resultant flux due to windings 30 and 20 under normal working conditions, and to conduce the current through 23 along an axis displaced by 180/n degrees with respect to the axis of 35. This arrangement, therefore, necessitates a displacement between the axis of 30 and of that of 23, as fixed by the position of the brushes on the commutator. As a result, only part of 23 can be neutralized by 30, and only part of 23 can produce a torque with F, at starting, the remaining part of 23 either increases or reduces, at starting, the current in the winding closed on itself. In case 23 has many turns as compared with 20, the necessary brush displacement might become inconveniently large; in such case the winding 30 can be dlvided into several roups of coaxial windings, all groups bemg connected in series at starting and in arallel when runnin ,by means of switch60.

he space position 0 35 must be decided by the parallel grouping of 30, and'the full speed conditions. A

Instead of disposing the brushes in contact with the commuted winding in the manner shown in Fig. 7 arrangements such as illustrated in Figs. 17 and 18 may be employed. The machine can be started with the brushes connected as shown, or brushes '50 in both figures may be disconnected at starting and connected up as shown when a sufiicient speed has been reached. In

7 either figure all the brushes may be shifted for instance through 45 degrees and made Fig. 19 indicates that the winding 22 permanently closed on itself ma be so closed over impedances 45 of any kind which can be carried somewhere on the rotor so as to obviate the use of slip rin s.

Havin c fully described my invention, what I' c aim as new and desire to secure by Letters Patent of the United States is:

1. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member rovided with a commuted I windin and a winding ermanently closed ing, and a neutralizing winding on said inducing member so connected with said induced member through one will bear a constant ratio to the current passing through thevother.

3. In an alternating currcnt'motor, the combination with an inducing member provided with a main inducing winding, of an rovided with a commuted windin and a winding permanently closed on itse f, a neutralizing winding on saidinducing member so connected with said commuted winding that the current passing through one will bear a constant ratio to the current passing through the other, and menus for varying the ampere turns of the neutralizing windlng. V

4. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted windin and a winding permanently closed on itse f, a neutralizing winding on said inducing member adapted to produce a magnetization displaced in space from that due to the said main inducing Winding, means for compensating the motor after starting, and means for conducting through said commuted winding a current derived from the line.

5. In an alternating current motor the ombination with an inducing member: rovided with a main inducing winding, 0 an induced member rovided with a commuted windin and a wlnding permanently closed on itse f, a neutralizing winding on said inducing member in series relation with said commuted winding and arranged to oppose the ma netization produced by said commuted Winding, and means for conducting through said commuted winding :1 current derived from the line.

6. In an alternating current motor, the

combination With an inducing member provided with a main inducing winding, ot an induced member provided with a commuted windin and a winding permanently closed on itsef, a neutralizing winding on said inducing member in series relation with said commuted winding and arranged to oppose the magnetization produced by said commuted winding, means for varying the ampere turns of said neutralizing winding,

and means for conducting through said commuted winding ,a current derived from the line.

7. In an alternating current motor, the

combination with an inducing member ro-.

means for cutting the neutralizing winding out of circuit after the motor has started 8. In an alternating current motor, the combination with an inducing member pro vided with a main inducing winding, of an induced member provided with a commuted windin and a winding permanently closed on itself, a neutralizing winding on said inducing member so connected with said commuted winding that the current passing through one will bear a constant ratio to the current passing through the other, and means for varying the volts per turn in said main inducing winding.

9. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted winding and a winding permanently closed on itself, 'a neutralizing winding on said inducing member so connected with said commuted winding that the current passing through one will bear a constant ratio to the current passin means for controlling the phase relation between the current in said commuted windin and the current in said neutralizing wlnding.

10. In an alternating current motor, the combination with an inducing member rovided with a main, inducing winding, 0 an induced member provided with a commuted winding and a wlnding permanently closed on itsclf,means for controlling the phase relation between the current in said main inducing winding and said commuted winding, a neutralizing winding on said induc ng member adapted to produce a magnetization displaced in space from that due to the said main inducing winding, means for controlling the phase relation between the current in said commuted winding and the current in said neutralizing winding, and means for conducting through said commuted winding a current derived from the line.

11. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of an induced member provided with a commuted winding and a winding permanently closed on itself, a neutralizing winding on said in ducing member adapted to produce a magnetization displaced in space from that due -to the said main inducing winding, means for controlling the phase relation between the current in said commuted winding and the current in said neutralizing winding, means for compensating the motor after starting, and means for conducting through said commuted winding a current derived from the line.

12. In an alternating current motor, the combination with an inducing member provided with a induced member provided with a commuted through the other, and

main inducing winding, of an winding and a winding on itself, a neutralizing ducing member adapted to produce a 1nagnetization displaced in space from that due to the main inducing winding, means for conducting through the commuted winding the current derived from the line, and means for short -circuiting the said commuted windingjalong an axis approximately coinculing with that of the main inducing winding. l

13. In an alternating current motor, the combination'with an inducing memberprovided with a main inducing winding, of'an induced member provided with a commuted winding and a winding permanently closed on itself, said commutedwinding bein connected in series relation with said in ucing winding, and means for compensating the motor.

14. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of an induced member provided with a commuted winding and a winding permanently closed on itself, said commuted'winding being connected in series relation with said main inducing winding, means for controlling the phase relation between the current in said main winding'and commuted winding for increasing the torque, and means for compensating the motor.

15. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of an induced member provided with a commuted winding and a winding permanently closed permanently closed winding on said 1non itself, a series transformer interposed between said main inducing winding and said commuted winding, and means for impressing on said commuted winding, after the motor has started, an E. M. F. derived from said transformer in order to compensate the motor.

16. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of an induced member provided with a commuted winding and a winding permanently closed on itself, a neutralizing winding on said inducing member arranged to oppose the magnetization produced by said commuted winding and means for compensating the motor.

17. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of an induced member provided with a commuted winding and a winding permanently closed on itself, said commuted winding being in series relation with said main inducing winding at starting, a neutralizing winding on said inducing member arranged to produce a magnetization substantially along the same axis as that produced by said commuted winding, and means for impressing a comt ensatingE. M.,F. on the commuted windmg after starting.

1-8; In-an alternating current motor, the

"combination with an inducing member provided wlth a ma n mducing winding, of an induced member provided with a commuted winding and a wlnding permanently closed on itself, a neutralizing winding on said inducing member arranged to produce a magnetization substantially along the same axis asthat produced by said commuted winding,

a series transformer interposed between said mducmg'member and sa1d commuted W111(l-' mg at starting, and means for impressing on said commuted winding after starting a compensating E. M. -F. derived from said transformer. r

19. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of a induced member provided with a commuted winding and a .winding permanently closed on itself, said commuted winding being in series relation with said main inducing winding at starting a neutralizing winding on said; inducing member arranged to produce a magnetization substantially along the same axis as that produced by said commuted winding, and means for cutting said neutralizing winding out of circuit after starting.

20. In an alternating current motor, the. combination withan inducing member provided with a main inducing winding, of an induced member provided with a commuted winding and a wlndin permanently closed on itself, a series trans ormer interposed between said main inducing winding and the commuted winding, a neutralizing winding on said inducing member arranged to produce a magnetization substantially along the sameaxis as that producedby said commuted winding, and means for impressing on said commuted winding after starting a compensating E. M. F. derived from said transformer.

21. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted winding and a winding permanently closed on itself, means for controlling the phase relation between the current in said main inducing winding and in said cominuted winding for the purpose of increasin the torque, a series transformer interposed etween said main inducing winding and the commuted .winding, a neutralizing winding on said inducing .memberarranged to produce a magnetization displaced in space from that due to the main inducing winding, and means for impressing on said commuted winding after starting a compensating E. M. F. derived from said transformer.

22. In an alternating current motor, the combination with an inducing member proincreasmg the torque,

vided with a main inducing winding, of an induced member provided with a commuted winding and a winding permanently closed on itself, means for controlling the phase relation between the current in said main inducing winding and commuted winding for increasing the torque, a series transformer interposed between said inducing 'membcr and commuted winding, a neutralizingwinding on said inducing member arranged to produce a magnetization displaced from that due to the said main inducing winding, means for cutting said neutralizing winding out of circuit after the motor has started, and means for impressing on said commuted winding after starting a compensating E. M. F. derived from said transformer.

23. In an alternating current motor, the combination with an inducing member provided with a main inducing winding, of an induced member rovided with a commuted winding and a winding permanently. closed on itself, means for controlling the phase relation between the current in said main inducing winding and commuted winding for a transformer interposed between said main inducing windin and commuted winding, a neutralizing win ing on said inducing member arranged to produce a ma etization displaced from that due to the main inducing winding, means for cutting said neutralizing winding out ofcircuit, means for impressing on said commuted winding after starting a compensatln E. M. F. derived from said transformer, an means for var ing the magnitude of said compensating M. F.

24. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted winding and a winding permanently closed on itself, means for controlling the phase relation between the current in said main inducing winding and commuted winding for increasing thetorque, a transformer mterposed between said main inducing wmding and commuted winding, a neutralizing winding on said inducing member adapte to produce a magnetization dlsplaced by 180/n degrees from that due to the main inducing winding, means for cutting saidneutralizmg winding out of circuit, meansfor impressing on said commuted winding after starting a compensating E. M. F. de-

rived from said transformer, and means for varying the magnitude of said compensating E. M. F.

25. In an alternating current motor, the combination with 'an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted windin and a winding permanently closed on itse f, means for controlling the phase ing and commuted winding, a neutralizing winding on said inducing member adapted to produce a magnetization displaced by 180/n degrees from that due to the main inducing winding, means for controlling the phase relation between the current in said commuted winding and the current in said neutralizing winding, means for cutting said neutralizing winding out of circuit, means for impressing on said commuted winding after starting a compensating E. M. F. derived from said transformer, and means for varying the magnitude of said compensating E. M; F.

26. In an alternating current motor the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted winding and a winding permanently closed on itself, means for controlling the phase relation between the current in said main inducing winding and commuted winding for increasing the torque, a transformer interposed between said main inducing winding and commuted winding, a neutralizing winding on said inducing member adapted to produce a magnetization displaced by 180/11 degrees from that due to themain inducing winding, means forcutting said neutralizing winding out of circuit, means for impressing on saidcommuted winding after starting a compensating E. M. F. de-

' rived from said transformer, means for Varying the magnitude of said compensating E. M. F and means for short-circuiting said commuted winding along an axis approximately coinciding with that of the main inducing winding.

27. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted .winding and a winding "permanently closed on itself, a neutralizing winding onsaid'inducing member adapted to produce a magnetization displaced in space by 180/n degrees from that due to the main inducing winding, means for conducting through said commuted Winding, along an axis coinciding with that of the neutralizing winding, a current derived from the line, means for cutting the neutralizing winding out of circuit, and means for impressing a compensating E. M. F. on the commuted winding after the motor has reached a sufiicient speed.

28. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted winding and a winding permanently closed on itself, a neutralizing winding on said inducing member adapted to produce a mag.- netization displaced in space by 180/n degrees from that due to the main inducing winding, means for conducting through said commuted winding, along an axis coinciding with that of the said neutralizing winding, a current derived from the line, and of means for impressing a compensating E. M. F. on the commuted winding after the motor has reached a sufiicient speed.

29. In an alternating current motor, the combination with an inducing member rovided with a main inducing winding, 0 an induced member provided with a commuted winding and a winding permanently closed on itself, a neutralizing winding on said inducing member adapted to produce a magnetization displaced in space by 180/n degrees from that due to themain inducing winding, means for conducting through said commuted winding along an axis coinciding with that of the said neutralizing winding,

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