DE2347153A1 - ASYNCHRONOUS MOTOR WITH SQUARE RUNNER WITH ADJUSTABLE TORQUE - Google Patents

Description

Patent attorneys

Dip !. Ing.H. ftcickniar.n, Dlpi. Pfrys. Dr.K. Finckö Dipl. Ing. F. A. Weickmann, Dipl. Ghern. ß. Huber

B Munich 27, BSShIsIr. 22nd

Sergio OCGHETTO, Turin / Italy, 1o / 4, Via Piossasco

The invention relates to a single-phase or multi-phase asynchronous motor with squirrel cage.

It is known that the drive torque and thus the speed to control the rotor wound by asynchronous motors by changing a load impedance for the rotor windings » which is connected to the rotor via suitable slip rings. This kind of motor control causes inevitable a considerable 'waste of energy. In practice, it is therefore aimed at increasing the torque under start-up conditions limited. The rotor windings are short-circuited during normal operation.

For asynchronous motors with squirrel cage rotors, which are the most interesting and important embodiment due to their low cost of asynchronous motors, this type of torque or speed control cannot be used will. As a result, the advantageous properties of these engines - namely their simplicity, their Robustness, their longevity, their low cost and the like - in many cases where this control option must exist, not be made usable.

The only previously known possibility for low-loss, continuous control of the speed of an asynchronous motor consists in the use of a stationary

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or rotating frequency converter or in changing the Supply voltage through saturation chokes or controllable rectifiers.

The frequency conversion is associated with high costs. It is also only suitable for low motor output powers and due to the need to control the induction value at low frequencies and the hysteresis losses at high frequencies to limit, only for a limited regulatory area. The reduction of the supply voltage, however, has the Disadvantage that - except when using squirrel cage rotors with high resistance - no large at low speeds Torques are possible. The use of a squirrel cage rotor with high resistance again has the disadvantage that the motor output becomes necessarily lower. There are also mechanical, hydraulic, electromechanical or electromagnetic torque converters driven by an induction motor have been used. These However, the type of control is high in cost and necessity frequent maintenance. In addition, this control possibility is to achieve a satisfactory control sensitivity often unsuitable.

The object of the invention is to create an asynchronous motor with a squirrel cage rotor, the torque of which can be regulated without that frequency converters, means for voltage control or sliding contacts are required.

Based on an electric asynchronous motor, the stator of which has a multi-phase winding, with a squirrel cage rotor formed rotor with laminated sheets of ferromagnetic material and distributed on the circumference axial conductor bars, which are connected to one another by short-circuit rings arranged on the end faces This object is achieved in that the stator comprises a first and a second winding section which are coaxial are arranged and adjacent to one another and the different

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Union areas of the rotor are opposite that the winding sections rait alternating current of the same frequency are fed and that means for changing the of the second winding section of the stator in the conductor bars of the rotor induced electromotive KrafV are provided.

In another aspect, the invention includes a linear one Induction motor with a first and a second movable with respect to it and inductively connected to it Part with polyphase windings, characterized in that the first part is a sequence comprises parallel conductor bars which are short-circuited laterally by longitudinal conductors that one extends along the Conductor rods extending support part made of ferromagnetic material is provided that the second part has a first and a second winding section comprising said winding sections are laterally adjacent to one another along the direction of the conductor bars and with alternating currents of the same frequency are fed and that means for changing that of the second winding section of the second part of the motor electromotive force induced in the conductor bars of the first part are provided.

Some preferred exemplary embodiments of the invention are explained in more detail below with reference to the drawings:

Fig. 1 is a sketch to explain the operation of the engine according to the invention,

Fig. 2 is a partially sectioned illustration of a first embodiment of the invention,

Fig. 3 shows operating characteristics of the engine shown in Fig. 2,

Fig. 4 shows the circuit of a second embodiment of the invention,

Fig. 5 shows the circuit of a third according to the invention designed engine,

Fig. 6 shows schematically a first embodiment of a

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Drive system rait an engine according to the invention,

Fig. 7 shows a second embodiment of such a drive sy st ems,

Fig. 8 shows a fourth embodiment of the invention Motors,

Fig. 9 illustrates a third embodiment of a drive system different from that on which the invention is based Principle makes use of that

Figures 10 to 16 are circuit diagrams for other uses of the motor of the present invention.

First, the principle on which the invention is based is described with reference to FIG. 1. Fig. 1 shows a rectangular one Conductor loop 10, which is held by bearings 12 and 14 so that it can rotate about an axis 16. It is assumed that the areas 13 and 15 are penetrated by two magnetic induction fields Β., And Bp, which along the axis 16 and are continuous perpendicular to this axis, have a constant absolute value and are about the axis 16 itself turn. Each of the fields B ,. and Bp acts on a demarcated Part of the conductor loop, where both parts have the same area S.

It is further believed that both magnetic induction fields have and in synchronization with an angular speed of revolving the value B, where they are mutually phase-shifted by an angle of <o _e, which can be changed as needed between 0 ° and 180 °. It is also assumed that the conductor loop rotates at an angular velocity of co ^ coaxial with the two magnetic induction fields.

The relative speed (slip) is then

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If 0 = BS, the part of the conductor loop that corresponds to the Field B ^ is exposed by a river with the instantaneous value

ψ _Λ = 0 cos co ^ t = BS ₀

interspersed. The part of the conductor loop which _{is exposed to field B 2} is controlled by a flow with the instantaneous value

_o = 0 cos ( (o t +6) = BS cos ( ίοΛ + tf) interspersed.

Therefore an induced electromotive force acts on the entire conductor loop, which has the value

~ dt

having. This results after insertion and some conversion

djTcosCid.'t + 5) c ° s 5J ß * 6

8 = 20 - - = 2AJ _o 0 sin ( λ) t +%) cos

It is immediately apparent that

for ^ = + 0 * e * 2 &> _s 0 sin <ü _g t
for 6T = + 180 ° £ = ο

If fZ | is the absolute value of the loop impedance and ψ is the phase angle of the loop impedance, the current becomes i = £ / Z in the loop

2 cousin (£ 0 _o t + -κ * - ψ) cos -5-

It is known that the instantaneous value of the

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acting torque

seed sections of the conductor loop ΙΟ / given is multiplied by the product of the value of the magnetic induction with the area of the loop projected in the direction of the field and multiplied by the value of the im considered time of current flowing through the conductor loop. The instantaneous value of the whole on the conductor loop The torque exerted is therefore given by the sum of the instantaneous values of the two torques:

C. _{n +} = O ₁ + C ₀ = BS i sincü t + BS i sin ( Co Λ sin (£> t + 6 ")

Λ * Ο C ι c. SSS -

This results from a simple conversion

CO 0 ²
C. = - I (1 + cos 6 *) [ cos f - cos (2 ^ t + & - "VOJ

The mean value C of the torque exerted on the conductor loop is

From this equation one obtains after carrying out the integration:

This expression shows that the average torque, which is caused s in each of the squirrel cage forming abrasive is a continuous function of the displacement angle, and that ⁰ to 180 ° is independent of the sign of the angle in the range of ^ = O.

If this calculation is repeated assuming that there is only field B ^ and that the conductor loop is accordingly short-circuited to the conductive parts exposed to the action of the field Bp in the previous case are to be eliminated, it can easily be demonstrated that the mean value of the drive torque that the conductor

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loop is communicated in this case, about half go is as large as the mean value in the present case at & = 0 °.

The situation corresponding to the case where there is only a single magnetic field is exactly the same the situation with an induction or asynchronous motor, for example a three-phase motor, if the resulting of the stator field generated in a multiphase motor is, as is known, exactly equivalent to a magnetic field whose amplitude is constant and whose direction rotates uniformly around the motor axis over time.

The theoretical considerations made above with regard to the presence of two magnetic induction fields B ^ and Bp are used for construction according to the invention of a motor is used, as shown schematically in a perspective sectional illustration in FIG. In This a rotor designed as a squirrel cage is rotatably mounted within a stator, the two sections 22 and 24 owns. Each slot of each section houses a winding, which is connected to a winding of the corresponding one Groove in the other section is congruent: the windings are, for example, three-phase windings and in delta connection connected with each other.

The squirrel cage 20 is equipped with conductor bars 26 which are similar to the bars of conventional squirrel cage. However, it only has laminated cores 28, 30 in the areas in which the two Statorab cut s generated magnetic fields is effective. The middle part of the squirrel cage therefore consists only of the conductor bars 26, there the presence of dynamo sheet in this area is not only unnecessary but even harmful, like every professional makes sense without further ado.

The sections of the ladder bars in the resulting intermediate

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interchangeable space can, for example, serve to store the ohmic Y / resistance of the ladder bars to vary. This can be, for example done by increasing or reducing their cross-sectional areas in this area. It is also possible to design the conductor bars in this area so that the heat radiation is improved.

By suitable mechanical means (not shown), the stator section 24 can be rotated relative to the stator section 22 between a position in which they act in phase (δ ' - 0 °) and a position in which they act in opposite directions ( 0 - 180).

The setting of the two stator sections can be according to the particular application of the motor and accordingly realized in different ways. With small engines where the reaction torque between stator and rotor is small, the Stator portion 24 be fastened in the (not shown) holding body with a friction clutch, since the frictional forces supply a sufficiently large torque to the second stator section in the required position keep. In this case, a joint or a small lever (not shown) is sufficient to achieve the required To effect shifting by hand. On the other hand, for motors with considerable power, the stator portion 24 be connected to a gear system that interacts with a (not shown) toothed worm or rack, which in turn are operated either by hand or by an electric, pneumatic or hydraulic servomotor will.

Fig. 3 shows the operating characteristics of an experimental mo- ■ tors, which was constructed according to FIG. In the direction of the ordinate axis, the drive torque C is in kg. cm and in The rotational speed η of the motor in revolutions / min is plotted in the direction of the abscissa axis. By-

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Solid lines relate to a supply voltage of 380 V, the broken lines to a supply voltage of 220 V. It can be clearly seen that by constantly increasing the displacement angle <o between the two stator sections, starting at & * - 0 °, a displacement of the Characteristic curves of the motor in such a way that the torque decreases until it is an order of magnitude below the maximum torque. With a constant load, a change in speed occurs which corresponds to the change in the drive torque. From Fig. 3, however, it can be seen that there is a tendency to throttle at low engine speeds when the displacement angle G * reaches values in the vicinity of 180 °. By changing the rotor resistance, the angle S ″ at which these phenomena begin to occur can be controlled. The motor constructed according to FIG. 2 can be used for various applications, for example as a traction motor or as a lifting motor.

Another embodiment of the engine according to the invention is shown in FIG. Like that shown in FIG Embodiment also has this motor a squirrel cage 20 with laminated cores 28 and 30, which by a Intermediate zone are separated from each other, as well as two stator sections 22 and 24, which have windings in a delta connection are shown, although a star connection of the windings is also possible. This engine is different of the motor shown in Fig. 2 in that the two stator sections are fixed, i.e. non-pivotable, and that the phase difference between one section and the other section is generated by electrical means. The section 22 is fed directly from the three-phase network, while the section 24 via an intermediate Phase shifter 34 is fed, which is a continuous Phase control allowed. It is clear that this creates a phase difference between the two Winding sections 22 and 24 generated magnetic in-

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duktionsfeidern arises, the phase shift is equivalent to that obtained in the engine shown in FIG
will.

This embodiment is more advantageous in some cases, for example when several motors are fed in parallel
as is the case with electric railroad locomotives.

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It is then possible to use a single phase shifter to be used to feed several stator-rotor groups arranged in parallel, which makes the installation costs obvious reduced v / earth.

Fig. 5 shows a third exemplary embodiment of an inventive Engine. Again, the phase difference between the magnetic fields is determined by electrical means generated. The motor has a rotor 20, which is identical to those already described, and two stator sections 22 and 24, which are arranged in a fixed relative position to one another. The stator section 22 is made directly from the Three-phase network 32 fed, while the section 24 is fed via switches 36, 38 and 40, which can be operated together are, and the supply voltage optionally to one of a plurality of groups of three terminals, for example 36a, 36b ..., 38a, 38b ... and 40a, 40b ... lie at the ends of successive winding taps of the phase windings of the stator section 24 are arranged. In this way the required phase difference between the magnetic fields generated by the two stator sections in a very simple, space-saving and effective way be generated.

To simplify the illustration, FIG. 5 shows four Winding taps, but it goes without saying that their number may vary if so by the envisaged Use appropriate tax needs is required. The design of the winding taps can also be different Based on criteria. For some uses, the designs may be uniform along each winding be provided, in other cases it may be more advantageous to use non-uniform designs. If switch after Kind of commutators are used, like with DC motors, an arrangement is obtained which is practically a continuous control of torque or speed is allowed. In this case, however, the

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Position the brushes in relation to, the commutator for each Control position fixed, so that the disadvantages existing, for example, in great wear and tear and in contact fire avoided that interfere with the use of commutators connected to the rotor.

In the drawing, the windings of section 22 are connected to one another in a delta connection. Instead, you can however, a star connection can also be used in this exemplary embodiment. However, this does not apply to the Stator section 24 to. Rather, a polygon connection is required for this in order to offset the phase shift of the feed taps to be able to realize.

It can be seen that this embodiment of the motor according to the invention allows the most general application, namely in every range of engine powers and sizes.

Fig. 6 shows in schematic form a diesel-electric drive system with an engine according to the invention.

The feeding electromotive force is generated here by a generator unit which comprises a diesel engine and a small field generator 48. The diesel engine 42 drives two alternating voltage generators 44 and 46 which produce three phase voltages of the same frequency. These feed the stator sections 22 and 24 of a motor whose rotor has the same structure as that of the exemplary embodiments described above. The supply voltage can also be fed to other motors (not shown) which are arranged in parallel.

The two stator sections 22 and 24 are fixed, i.e. cannot be rotated relative to one another.

The rotors (not shown) of the alternators 44 and 46 are opposed by a differential device 50

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rotatable with each other. The differential device 50 can either manually or by means of a servo motor via a Control device 52 can be operated so that the displacement angle between the rotors of the two alternators changes, which also changes the phase difference between the voltages they generate. In this way an adjustable phase difference between the currents fed to the stator sections 22 and 24 can be achieved. This way of influencing the relative phase angle is similar to that described with reference to the preceding figures Control type.

In Fig. 7, a further diesel-electric drive system is shown, which the mechanical complications that may be associated with the use of the differential device 50 is avoided. The drive system shown in FIG also has a diesel engine 42, a field generator 48, a motor with two stator sections and a rotor 20 designed as a squirrel cage and of the type described above.

The two alternators to power the stator sections 22 and 24 (as well as the stator sections of any further parallel-connected Motors) are replaced in this embodiment by a one-piece rotor 54, which is equipped with two columns 56 and cooperates, the windings of which are each connected in a delta connection and of which the first directly to the The stator section 22 of the motor is connected while the second is connected to the stator section 24 via winding taps is connectable. The structure of this arrangement is the same as that used in the description of the stator portion 24 was explained in FIG. 5.

In this way, a phase difference between the supply currents for the two stator sections of the motor is possible to create. The mean to phase shift that occurs in the

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previously described embodiments components of the engine were, in this arrangement, transferred to the generator to generate the supply energy. It is obvious, that this transfer of the means for phase shifting is particularly favorable when a single Generator is to feed several motors connected in parallel.

Instead of the arrangement shown in FIG. 7, of course other means for phase shifting in the generator are also used, for example means for relative pivoting of the two stator parts 56 and 58 in a manner which is similar to that described with reference to FIG.

Fig. 8 shows a further embodiment of the invention Motor having a control range of not more than 50% of the maximum of the motor with double stator according to the invention achievable torque allowed.

In this case, the squirrel cage 16 is similar to the rotor 20 used in the arrangements described above finds. It comprises a plurality of conductor bars 26 and two packages of dynamo sheets 28 and 30, which run along the rotor axis are separated from each other. In this case, however, the packet 30 extends over the squirrel cage in the area 62 addition, the additional length being substantially equal to the length of a single package in that illustrated in FIG Arrangement is.

The stator section 22, the windings of which are connected to one another in a star connection in the drawing , although a delta connection is of course also possible, corresponds to the stator sections 22 of the arrangements described above. The stator section 66, which is also fed directly from the supply source, is continuously displaceable in the axial direction from a position

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in which it completely surrounds the conductor cage of the rotor, up to a position in which it surrounds the part 62 of the laminated core, the is not connected to the ladder cage.

This arrangement of the stator section 24 makes it possible to increase the amplitude instead of the phase of the magnetic field generated by the second stator section in the conductor cage vary. The end result is the same, as the size of the in the second section of the conductor point The electromotive force induced by the rotor is caused by the change in the flux passing through the conductor cage changes.

When the angular position of section 66 and that of section 22 match, the torque can be varied between about $ 50 and $ 100 of the maximum if the Position is out of phase, the torque can be varied between zero and about 50 ° of the maximum value.

It is of course also possible to provide the motor shown in FIG. 8 with a switch which can be actuated when the stator section 66 is in the second end position. This means that the entire range from 0% to 10096 can be covered by switching from in-phase to antiphase feed for the two sections.

In Fig. 9, an embodiment of a linear motor according to the invention is shown, which is particularly suitable for Drive of monorail vehicles is suitable. It is described in more detail below:

In this case the rotor has an infinitely large radius or it becomes ladder-shaped by a band of arranged conductor bars 70 replaced, which are laterally short-circuited by longitudinal conductor bars 72. That

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Band of conductor bars 70 is made with a band 74 of ferromagnetic Material connected, which here the task of the laminated cores of the rotor of the embodiments described above takes over. The band of ladder bars that is used when the arrangement is used to drive monorail vehicles For example, it is carried on the side of the rail itself, represents the stationary part of the motor that However, the working principle is the same.

The stator sections (which are mounted on a movable vehicle when used as a drive motor) are arranged side by side and at right angles to the direction of travel of the vehicle, and during one of to them, section 76, is fed directly from a suitable three-phase power source, the other section becomes 78 fed via commutators 80, 82, 84, which regulate the phase shift of the impressed electromotive Allow strength. The operation of this linear motor is without further explanation from the above descriptions other embodiments of the invention can be seen.

It goes without saying that in the embodiment shown in FIG. 9, the devices can also be used are, which were described with reference to the drive systems shown in Figures 6 and 7, if diesel electric drive is used for the vehicle, i.e. the means for phase shifting can be from the engine to the Generator.

FIGS. 10, 11 and 12 show further embodiments of the motor according to the invention for special purposes.

In Fig. 10, a rotor similar to the rotor shown in Fig. 2 is in two stator sections 22 and 24, the the same shown in Fig. 2, rotatably mounted. Of the

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first section 22 is directly connected to the three-phase network. The second section 24 has no angular difference arranged to the first section. It feeds electrical energy back into the network via suitable current regulators 86, since the Arrangement is made so that in the second winding section a voltage is generated which is greater than the supply voltage. The circuit of FIG. 10 can be used as a voltage or frequency converter, since the Energy absorbed by the first winding section (minus the rotor losses) by the second section is fed back.

The exemplary embodiment shown in FIG. 11 is similar to the exemplary embodiment according to FIG. 10, the second stator section However, 24 is arranged in phase opposition to the first section 22. In this case, the current regulator 86 acts not as a transmission medium for the transmission of energy from the stator section 24 into the supply network 32, he rather, it prevents the stator section 22 from transferring more energy to the rotor than for the generation of the desired one Torque and the desired speed of rotation is required. The device works on this Way as an electromagnetic torque regulator.

FIGS. 12 and 13 show two further exemplary embodiments of the motor according to the invention. They will be amplitude and phase of the supply for the second section 24 controlled by three_phase auto_transformators 88 and 89, respectively.

14 and 15 show two further exemplary embodiments in which the windings of the two stator sections are connected in star series or in delta series. They refer to an engine in which the phase difference between the stator fields is created by mechanical means. With this type of supply one obtains Working characteristics that are more suitable for drive purposes. They resemble the working characteristics of DC motors

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Series excitation.

In order to avoid the use of mechanical means for phase shifting, those shown in FIGS. 15 and 16 are possible To replace circuits by the arrangement according to FIG. 16, in which the second section 24 in delta connection and is fed in series with the windings of the first section 22 connected in a star connection. This makes it possible to use, for example, coramutator switches 36, 38, 40 as a means for phase shifting.

The preceding description of various exemplary embodiments of the motor according to the invention always referred to three-phase windings in star or delta connection. The principle on which the invention is based can of course also be used can be implemented for motors with a different number of phases, for example with a six-phase motor or with a single-phase induction motor can be used. The single-phase version of the motor according to the invention is particularly suitable for use in electrical household appliances, for example in Washing machines or dishwashers are suitable, in which, for example, the arrangement shown in FIG. 5 is used can be, whereby different washing or spinning speeds or the like with an extraordinary simple, robust and cheap motor can be achieved. Usually present in such machines as Timers designed as program switches can directly actuate commutators 36, 38 and 40.

Although the two stator sections in motors for many applications will be identical, it goes without saying that they can also be designed differently, if control is only required within a limited speed range.

It should finally be mentioned that the inventive Asynchronous motor with squirrel cage in combination with a suitable one known control system with feedback

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loop can be used for applications where precise speed control is required, e.g. in the control of machine tools or the like. This way you become a simple and cheap engine Use cases opened up that were previously inaccessible to him.

A few exemplary embodiments of the invention have been described above; there are of course numerous variants possible, all of which make use of the knowledge on which the invention is based, which consists in two stator sections and means for acting on the supply or on the angular position or on the axial position of the to use the second stator section and in this way those of this section in the conductor bars of the squirrel cage to change induced electromotive force.

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- 20 -

Claims (1)

Electric asynchronous motor, the stator of which is a multiple, phase winding carries, with a trained as a squirrel cage Rotor with laminated sheets made of ferromagnetic material and distributed on the circumference axial conductor bars, which are connected to one another by short-circuit rings arranged on the end faces (squirrel-cage motor), characterized, that the stator comprises a first (22) and a second (24) winding section which are arranged coaxially and adjacent to one another and the different areas (28, 30) of the rotor (20) oppose that the winding sections (22, 24) are fed with alternating current of the same frequency and that means (34; 36, 38, 40; 44, 46, 50, 52; 86; 88; 89) for changing the of the second winding section of the Stator in the conductor bars of the rotor induced electromotive force are provided. 2. Motor according to claim 1, characterized in that the rotor (20) only in the Winding sections (22, 24) of the stator opposite areas laminated cores made of ferromagnetic material having. (_3y linear induction motor consisting of a first Part and a second part with multi-phase windings, which is movable in relation to this, characterized in that the first part comprises a succession of parallel conductor bars (70) which are short-circuited laterally by longitudinal conductors (72), that one extending along the conductor bars (70) Support part (74) made of ferromagnetic material is provided that the second part has a first 409 8 13/0933 - 21 - and a second winding section (76, 78) comprising said winding sections (76, 78) along the direction of the conductor bars (70) are laterally adjacent to one another and are fed with alternating currents of the same frequency and that means (80, 82, 84) for changing the of the second winding portion (78) of the second part of the Motor in the conductor bars (70) of the first part induced electromotive force are provided. 4. Motor according to one of claims 1 to 3, since d u r c h characterized in that the two winding sections (22, 24 and 76, 78) of the stator or the second part of the motor are electrically identical. 5. Motor according to one of claims 1 to 4, characterized characterized in that the means for changing the induced electromotive force means for influencing it the phase shift between the magnetic field generated by the first winding section are. 6. Motor according to claim 5, insofar as it is referred back to claim 1 or 2, characterized in that that the two winding sections are arranged on mutually rotatable support parts and that the means for phase shifting the magnetic field are means for mutual rotation of the carrier parts are. 7. Motor according to claim 5, characterized that the means for phase shifting the magnetic fields of means for shifting the Phase relationship formed between the feed current of the second and the feed current of the first winding section are. - 22 409813/0933. O * \ L "7 Λ 8. Motor according to claim 7, characterized draws that the means for phase shifting zv / ischen the feed currents from an inductive phase shifter (34), which are cascaded in the feed circuit of the second winding section is inserted. 9. Motor after. Claim 7, in which at least the windings of the second winding section (24; 78) are connected to one another in a polygon circuit, characterized in that the means for phase shifting are made up of a plurality of taps provided on the individual sides of the winding polygon forming the second winding section ( 36a to 36d, 38a to 38d, 40a to 40d) and selector switches (36, 38, 40) which are connected to these taps and which can be operated simultaneously and in mutual correspondence to connect the supply circuit with preselected congruent winding taps on each side. 10. Motor according to claim 9, characterized in that the selector switches (36, 38, 40) Commutator switches are. 11. Motor according to claim 7, which is fed by two mutually synchronously rotating alternators, characterized in that the means for phase shifting consists of coupling means (50, 52) are formed, which cause a mutual rotation of the rotors of the two alternators (44, 46) allow. 12. An engine according to claim 7, that of an alternator equipped with a rotor and two stator is fed, at least one of the stator windings being connected to one another in a polygon circuit, 409813/0933 - 23- characterized in that the means for phase shifting is selected from a plurality of winding taps and provided on the individual sides of the winding polygon (58) of this stator are formed from selector switches that are connected to said plurality of winding taps and used for Connection of the food torrent circuit rait selected congruent winding taps on each side simultaneously and can be operated in mutual agreement. 13. Motor according to one of claims 1 to 4, characterized in that the means for changing the electromotive force means for changing the amplitude of the supply current of the second winding section are. 14. Motor according to one of claims 1 to 4, characterized in that the means for changing the electromotive force are formed by means for displacing the second winding section which this parallel to the axial conductor bars of the squirrel cage between a position in which it Ladder bars faces with its entire length and is displaceable in a position in which it is them not facing .. 15. Motor according to one of claims 1 or 2, characterized in that the supply of the second winding section can be controlled by a current regulator (86) through which the amplitude of the feed current is changeable. 16. Motor according to claim 6, characterized in that the windings of the second Winding section in star connection with one another and in series with those connected to the supply source Windings of the first winding section 40981 3/0933 are connected. 17 »Motor according to claim 6, characterized in that the first and the second winding section are fed in a series star connection. 18. Motor according to claim 6, characterized in that the first and the second winding section are fed in a series polygon circuit. 19. Motor according to claim 1 to 5, characterized in that the windings of the second winding section are connected to one another in a polygon circuit and over the windings of the first winding section over between the two winding sections in a cascade connection inserted phase shifters are fed. 20. Motor according to one or more of the preceding claims, characterized in that it is a Three-phase three-phase motor is. 21. Motor according to one or more of claims 1 to 19, characterized in that it is a Single phase AC motor with phase advancing capacitor is. 09813/0933