Coupled motor system

Abstract

The invention relates to an electric machine system (1) having an even number of mechanically and electromagnetically coupled sub - machines (2 - 5) which generate rotating fields, said sub - machines having a common magnetic section and common coils (10 - 15), wherein each sub - machine is electromagnetically coupled to two adjacent sub - machines, and wherein at least two adjacent sub - machines (2, 3) have the same direction of rotation (22).

Description

Field of the Invention

[0001] The present invention relates to an electric machine system having an even number of, preferably a number divisible by four, mechanically and electromagnetically coupled sub - machines that generate a rotating field, the sub - machines having a common magnetic section and a common coil, wherein each sub - machine is electromagnetically coupled to two adjacent sub - machines. That is, each sub - machine is electromagnetically coupled to at least two or more even - numbered adjacent sub - machines, preferably exactly two adjacent sub - machines. Background Art

[0002] The sub - machines can be connected, for example, by a mechanical transmission. Electric drive devices with a transmission stage are often implemented using electric machines, such as permanently magnet - excited or electrically excited synchronous machines, asynchronous machines, reluctance machines, etc., to which a single - stage or multi - stage transmission is mechanically connected on the output shaft.

[0003] In electrical engineering, a rotating field in particular refers to a magnetic field that rotates continuously about a rotation axis. In an electric machine or sub - machine that generates a rotating field (simply referred to as a rotating - field machine), physical quantities such as current, voltage, and magnetic flux regularly change their signs during operation. For example, during operation, at a constant rotational speed, physical quantities such as current, voltage, and magnetic flux change more or less sinusoidally. Rotating - field machines operate using at least two phases.

[0004] From WO 2004 / 047256 A1, a generator with multiple outputs is known, in which a plurality of generator units are mounted around a main shaft inside a housing. Here, a pressed - in drive wheel drives a plurality of rotors that rotate in the same direction. Compared with the present disclosure, this has the disadvantage that each rotor requires a fully constructed stator. The sub - machines are not electromagnetically coupled. Thus, geometric simplifications for reducing materials cannot be made in the stator structure.

[0005] In DE 10 2009 010 162 A1, another electric machine system is shown in which the sub - machines are not electromagnetically coupled.

[0006] Furthermore, in DE 10 2013 213 847 A1 or in the corresponding WO 2015 / 007441 A2, an arrangement of a plurality of electric machines is disclosed, which are connected by a downstream - connected transmission. It is disclosed that adjacent sub - machines, i.e., electromagnetically coupled sub - machines, only have opposite rotational directions here, or an arrangement with an odd number of sub - machines is involved, which requires a correspondingly high structural expenditure.

[0007] An electric drive device with a rotor having multiple permanent magnet excitations is known from EP 0 721 248 A2, where these rotors are respectively associated with three stator poles. This drive device is arranged for a dry shaver, in which the rotors rotate without mutual mechanical connection, which is common in shavers. The disadvantage of this is that there is no mechanical coupling that preferably increases the torque.

[0008] Another arrangement is given in EP 0 678 966 Al, which has two parallel rotors and a magnetic circuit acting on the two rotors. In one example, the two rotors have different numbers of poles. However, this disclosure is limited to rotors with opposite rotational directions.

[0009] Finally, a multi-rotor arrangement is also shown in DE 2006 386C1, which acts together with the rotating field of a common stator system. Due to the matrix arrangement, an economically constructed transmission for connecting the rotors is not possible, and due to the target application (centrifuge), no mechanical coupling is sought or disclosed either.

[0010] WO 2018 / 006109 A1 shows a motor system of the same type, however, in which adjacent sub-motors always operate in opposite rotational directions.

[0011] US2 782 328 A shows a motor system that has four sub-motors with partially the same and partially opposite rotational directions between adjacent sub-motors. However, here each sub-motor is electromagnetically coupled to each of the other three sub-motors, that is, not electromagnetically coupled to an even number of sub-motors. In addition, the sub-motors do not generate a rotating field, but rather a pulsating torque similar to single-phase operation. Here, the field pulsates axially between two axial blocks of the rotor. This document shows in detail a winding system in which all coils have a flux path in the same phase or in the opposite phase, or are traversed by a flux path in the same phase or in the opposite phase. Therefore, the induced voltages in all coils are either in the same phase or in the opposite phase. Thus, a single-phase arrangement that cannot form a rotating field is presented.

[0012] WO 2012 / 164052 A2 shows a motor system with adjacent rotors whose rotational directions are oriented in the same way. However, these embodiments relate to "Switched Reluctance" motors that do not generate a rotating field. In these motors, parameters such as line current (Strangstrom) do not change their sign, and to a certain extent, current blocks (Stromblock) with the same sign are always applied. This causes strong torque fluctuations.

[0013] US 5,780,950 A discloses an electric machine system having a plurality of rotors axially arranged on a common stator, the shafts of the rotors being mechanically connectable to each other. It has been shown that all the coils are linked with flux paths such that all these flux paths simultaneously have their maximum or zero-crossing points. Thus, the characteristics of a single-phase electric machine with fluctuating torque are also presented here. Therefore, a rotating field cannot be generated either.

[0014] EP 2 209 188 A2 shows an electric machine system having pairs of motors or generators sharing a magnetic section. It is not shown that each sub-machine is electromagnetically coupled to two adjacent sub-machines, but only to another machine. In other words: in EP 2 209 188 A2, only two adjacent sub-machines are electromagnetically coupled, i.e., in pairs. The corresponding two coupled sub-machines together generate a pulsating magnetic field, which induces a single-phase alternating voltage in the winding system associated with these two sub-machines and utilizing the mentioned magnetic field linkage. This means that a strongly pulsating torque is induced in all the sub-machines. None of the shown sub-machines generates a rotating field. Summary of the Invention

[0015] The technical problem to be solved by the present invention is to provide an electric machine system as described at the beginning, wherein, on the one hand, the above-mentioned drawbacks are avoided, and on the other hand, due to a new electric machine structure with a large number of geometric degrees of freedom, the electric machine system can be constructed particularly compactly.

[0016] The above technical problem is solved by the present invention, which provides an electric machine system according to the appended claims. Thus, an electric machine system is provided, which has an even number of mechanically and electromagnetically coupled sub-machines, the sub-machines generating a rotating field, wherein the sub-machines have a common magnetic section and a common coil, wherein each sub-machine is electromagnetically coupled to two adjacent sub-machines, and wherein at least two adjacent sub-machines have the same direction of rotation.

[0017] Thus, the present invention provides an electric machine system having an arrangement of a plurality of electrically and mechanically coupled sub-machines. The sub-machines can be mechanically coupled, for example, by a transmission. The relative direction of rotation between the sub-machines is a structural characteristic of the mechanical coupling.

[0018] The coils arranged on the magnetically conductive connecting core columns can be electrically connected into a three-phase winding system with any number of circuits (phases), preferably three or two circuits. Here, a compact structure of the motor system composed of sub-motors can be achieved because, due to this geometric arrangement, certain parts of the sub-motors can be omitted, since the flux components of adjacent sub-motors are compensated segmentally, thus saving or economizing on magnetically active materials. On the other hand, the mechanical coupling of the sub-motors can advantageously be implemented as a mechanical planetary gear with a desired transmission ratio, whereby components of the planetary gear, such as supports, coupling devices (Kupplung), and housing parts, can be saved or double-used compared to a discrete structure composed of a motor and a functionally separate planetary gear. In addition, in the current motor system, the planetary gear connected to the sub-motor has only one contact on the tooth surface, whereby losses can be significantly reduced compared to a normal planetary gear transmission.

[0019] In addition, the sub-motors can transfer part of the torque or force they generate, regardless of mechanical manufacturing tolerances, for example, to the planetary gear associated with the sub-motor through a direct mechanical connection. Thus, the division of the single-axis torque of the motor via the gear to the planet is eliminated; instead, the torque is directly divided by the sub-motors. Therefore, the corresponding power of the sub-motors can be divided by 1 / n (n = the number of planetary gears or sub-motors) compared to the power of the associated single motor. In addition to a greatly simplified design, this results in another significant advantage: because, according to experience, in high-speed drives, mainly due to strength reasons, the circumferential speed is limited to a few hundred meters per second, so at the same limited circumferential speed of the sub-rotors, significantly more electrical power can be installed in the same volume. For example, if the rotor is divided into four sub-rotors with the same total rotor area, the sub-rotors have half the diameter of the original rotor. If it is assumed that the specific thrust per unit area in the air gap (spezifischen Schub pro ) is the same, half the diameter or half the circumference of the original rotor means half the thrust for each sub-rotor. Therefore, multiplying by half the radius of the original rotor, each sub-rotor provides a quarter of the original torque, divided into area-neutral sub-rotors that overall provide the same torque, that is, the same power can be provided at the same rotational speed as the original through the sub-rotors. Therefore, the same power can be achieved at half the circumferential speed in the current system, thus obtaining a great advantage in mechanical implementation. That is, in principle, there is also a reserve for doubling the rotational speed and thus the installed power in order to reach the same circumferential speed. In addition, the transmission function causing the mechanical coupling can advantageously be used to show the transmission ratio between the rotor rotational speed and the transmission output rotational speed.

[0020] Generally speaking, the present invention also relates to motor systems as follows, in which all sub-motors have the same rotation direction. If the motor system has at least four sub-motors, where half of the corresponding adjacent sub-motors have opposite rotation directions and the other half of the corresponding adjacent sub-motors have the same rotation direction as the corresponding sub-motors, a particularly compact and efficient solution can be achieved. Due to the partially same and partially opposite rotation directions of adjacent sub-motors, when connecting the coils to the circuit, the longer and shorter well-magnetically-conductive connecting cores can be magnetically coupled, so that the same magnetic situation exists in the circuit, and thus a more uniform torque and an as-symmetrical-as-possible three-phase alternating voltage system can be realized.

[0021] According to an exemplary embodiment, each sub-motor can be electromagnetically coupled to exactly two adjacent sub-motors. These two sub-motors adjacent to the sub-motor run in opposite directions here, so that each sub-motor has a neighbor running in the same direction and a neighbor running in the opposite direction.

[0022] In addition, at least one sub-motor can be electromagnetically coupled to an adjacent sub-motor with the same rotation direction by exactly one core. As a "core", here it refers to a well-magnetically-conductive connecting piece between two adjacent rotors. For example, exactly one pole shoe of one sub-motor and exactly one pole shoe of another adjacent sub-motor can be formed by or connected to the core. The pole shoes along the rotor circumference are usually arranged in the same way along the circumference. In other embodiments, these pole shoes can be arranged differently along the circumference and / or have different angular spreads with respect to the rotation point of the rotor, thereby giving geometric advantages such as higher compactness or electromagnetic advantages such as optimized torque formation.

[0023] Preferably, a coil is provided on each well-magnetically-conductive core, and the coils are connected into a three-phase alternating current system according to known electrical engineering methods. Of course, the coils can also be composed of multiple sub-coils, thereby achieving great flexibility in wiring, so as to achieve redundancy in case of sub-coil failures, etc.

[0024] In addition, in this case, at least one sub-motor can be electromagnetically coupled to an adjacent sub-motor with an opposite rotation direction by exactly two cores.

[0025] In addition, within the scope of the present disclosure, at least two adjacent sub-motors with the same rotation direction can have rotors with different numbers of poles. Here, the numbers of poles of the two sub-motors preferably follow the ratio u:g, where u is a positive odd integer and g is a positive even integer, or the ratio l:n, where n is a positive integer greater than or equal to 2, preferably the ratio 1:2.

[0026] Furthermore, the coils of at least two adjacent sub-motors, preferably all mechanically and electromagnetically coupled sub-motors, can be connected to form a three-wire winding system. The disclosed motor system can be a three-phase AC motor. Particularly advantageously, one or two core columns are associated in an alternating manner between adjacent sub-motors. In this case, the electromagnetic coupling with adjacent sub-motors correspondingly includes at most two wires. Thus, in each sub-motor, a total of three wires are divided among two (or more) different adjacent sub-motors. This enables a particularly compact structure of the stator.

[0027] Furthermore, it can be provided that the rotor of at least one of the sub-motors is only bipolar or only quadrupole.

[0028] The mechanical coupling of the sub-motors can be defined, for example, by a transmission function that simultaneously defines the transmission ratio between the rotor speed and the transmission output speed. Preferably, the sub-motors are mechanically coupled for numerically identical speeds.

[0029] According to a preferred embodiment, the sub-motor can be a rotor operating synchronously with permanent magnet excitation, electrical excitation, and / or reluctance characteristics. On the other hand, the sub-motor can also be a rotor operating asynchronously in the form of a short-circuit rotor and / or a slip-ring rotor.

[0030] The control of the coil system can be carried out by a power electronic actuator according to a control method known per se for three-phase motors; furthermore, with the aid of a computing device, via a sensorless method, based on a mathematical model, the intermediate electrical rotor position of the sub-motor can be determined. As an example, AT 508 854B is mentioned. Furthermore, in M. “Sensorless Control of A.C. machines”, Fortschrittsbericht VDI, Reihe 21, Nr. 117 (VDI-Verlag Düsseldorf 1992), a mathematical model is given.

[0031] The mechanical coupling of the sub-motors can also be carried out in a manner known per se such that the execution of the resulting linear motion is achieved. For example, when on both sides of a rack, corresponding identically operating motor pairs are mechanically coupled using the rack, this is particularly advantageous in combination with sub-motors operating in the same rotational direction in pairs, where the motor pairs opposite to each other with respect to the rack have opposite rotational directions.

[0032] For simply adjusting the magnetic flux linkage formed in the coil, it is also advantageous if the average angular positions of at least two, preferably all, of the sub-motors are mechanically variable relative to one another during operation. Thus, the terminal voltage (Klemmenspannung) can also be influenced and, if required, reduced to near zero.

[0033] The electric machine system can have a shaft that bears one or more transmission elements, where the one or more transmission elements mechanically couple the sub-motors, and where the shaft is optionally mechanically connected by means of a differential gear (Differenzialgetriebe); here, for space savings, the shaft is preferably embodied as a hollow shaft.

[0034] In an electric machine system of the invention of the type described above, at least a part of the coils of the stator can be cooled. Cooling can be effected, for example, by means of cooling plates and / or by cooling elements between the coil and a highly permeable core or as close as possible to the coil and the highly permeable core. For example, convective removal of heat from the active elements of the stator can be achieved by means of a coolant, and improved thermal coupling with a cooling unit outside the electric machine system can be achieved.

[0035] At least a part of the core of the stator that bears the coils can comprise a magnetically permeable material having a preferred direction. Preferably, all cores of the stator or all parts that bear the coils have or are made of this material. This material can be transformer sheet or have similar properties. If the magnetically permeable stator parts (especially the cores) are embodied such that they enable as "straight" a path as possible for the magnetic flux guidance, advantageously, particle-oriented sheets with low losses can be used. Description of the Drawings

[0036] Below, the invention is further explained on the basis of embodiments shown in the drawings, but the invention is not limited to these embodiments. Specifically, in the drawings:

[0037] Figure 1 A schematic arrangement of an electric machine system having four sub-motors is shown;

[0038] Figure 2A and 2B For comparison, schematically shown in Figure 2A is an electric machine system having four sub-motors according to WO 2018 / 006109A1, and shown in Figure 2B is an electric machine system according to the present disclosure;

[0039] Figure 3 A mechanical coupling of half of a sub-motor is shown, here as an example of a mechanical coupling using only external toothing gears, with a central gear and corresponding reversing wheels;

[0040] Figure 4 shows another example of a mechanical coupling, here a mechanical coupling using internal and external toothed rings;

[0041] Figure 5 further shows an example of a mechanical coupling similar to Figure 3 where, instead of two reversing wheels, a common intermediate wheel is provided, i.e., the intermediate wheel is associated with more than one sub-motor;

[0042] Figures 6A to 6D schematically shows a segment of a motor system having two adjacent sub-motors, where the sub-motors have rotors with different numbers of poles; and

[0043] Figure 7 schematically shows a mechanical pre-coupling of four sub-motors for performing a linear motion. Detailed Description

[0044] In Figure 1 a motor system 1 with four mechanically and electromagnetically coupled sub-motors 2 - 5 is shown. The sub-motors 2 - 5 each have a permanently magnetically excited rotor 6 - 9. Between the adjacent rotors 6 - 9, one or two core columns 10 - 15 are respectively arranged. The core columns 10 - 15 are shown in a highly simplified structure without showing flaps and gaps. The core columns 10 - 15 each have coils, i.e., a total of six coils 16 - 21 (in Figure 1 each of the coils 16 - 21 consists of two sub-coils, for example, and of course a single coil not separated into sub-coils can also be used), where the corresponding two coils 16 - 21 are associated with the same line (corresponding to one phase). For example, coils 16, 19 are associated with the first line ("u"), coils 17, 20 are associated with the second line ("v"), and coils 18, 21 are associated with the third line ("w"). In the case where the four rotors 6 - 9 are the same, the two sub-motors 2, 3 electromagnetically coupled to the core column 10 have a first rotational direction 22. The two sub-motors 4, 5 electromagnetically coupled to the core column 13 have a second rotational direction 23 opposite to the first rotational direction 22. Correspondingly, the two sub-motors 3, 4 electromagnetically coupled to the two core columns 11, 12 have opposite rotational directions 22, 23; the same applies to the sub-motors 2, 5 electromagnetically coupled to the two core columns 14, 15.

[0045] According to Figure 1 the three-line arrangement has the advantage that common three-line controlled by a converter. The two coils 16 - 21 belonging to one line, for example u1 to u4, etc., can be selectively connected in series or in parallel, because they continuously carry the same magnetic flux. However, they can also be controlled by separate converters (not shown), so that, for example, redundancy or increased power can be achieved. The control of the converter is advantageously carried out according to control methods known per se for three-phase motors, such as field-oriented regulation, where, since it is known per se, a more detailed description can be omitted here. Here, when using so-called "sensorless" methods, such as the method or the EMK method, the rotary encoder (Drehgeber) can often be omitted. Then, for the converter, the "multi-motor system" behaves like a single motor in terms of terminal characteristics.

[0046] The coils 17, 20, 18, 21 of phases v1,4 and v2,3 as well as w1,4 and w2,3 have substantially the same length, because in each phase, one coil is located on the outside of the arrangement and (in the other sub-motor pair) one coil is located on the inside of the arrangement. That is, relative to an arrangement with four rotation directions set in an alternately opposite manner, in one sub-motor pair, the phases are mirrored about the dashed mirror axis 24.

[0047] In Figure 2A the corresponding mirror axis in a motor system not according to the present invention is shown: The mirroring of the relevant sub-motor pair about this axis results in a motor system according to the present invention according to Figure 2B This enables several advantages: On the one hand, in order to transfer the magnetic flux to the magnetically conductive stator part, the rotor circumference is divided into different angular segments. Through the possible geometric freedoms thereby, a very compact structure can be achieved.

[0048] Thereby, compared to, for example, the symmetrical division of the rotor circumference onto the stator lines known from the prior art (such as DE 10 2013 213 847 Al), significantly less magnetically conductive material is required. Additionally, through this non-uniform arrangement, as "straight" a magnetic flux guidance as possible can be achieved within the magnetically well-conductive stator parts (i.e., essentially the core columns 10 - 15). Thus, these stator parts with preferred magnetic directions can be implemented similarly to transformer sheets, and it is known that transformer sheets have better characteristics in terms of losses, magnetic voltage drop, and allowable magnetic flux density in the preferred direction. Finally, the arrangement of the magnetically conductive stator parts within the common circumference around the rotor 6 - 9 (the rotor 6 - 9 extends around the air gap) enables a very compact housing structure and a very light-weight stator part.

[0049] In Figure 2BIn the example shown, a heat-dissipating, preferably liquid, medium is used and the cooling unit 25 is arranged adjacent to at least one of the coil boundary surfaces, which are formed by the sections "coil head", "coil back", "coil side", "coil inner surface". Thereby, a tight thermal coupling can be provided between the heat-generating coils 16 - 21 (and the also heat-generating stator parts guiding the magnetic flux) and the cooling unit 25.

[0050] The mechanical coupling of the sub-motors 2 - 5 can be achieved in the same way by means of a form-fitting connection, preferably a gear (alternatively by means of a toothed belt, chain, etc.). It should be noted that in rotors whose function is independent of the rotor angle, for example in asynchronous motors, a friction-fit connection is also permitted.

[0051] In Figure 3 an example with only external-tooth gears 26 - 32 is given. The gears 27 - 30 are respectively associated with the sub-motors 2 - 5, that is, connected to the shafts of the rotors 6 - 9. The two intermediate gears 31, 32 reverse the direction of rotation of the adjacent sub-motors 2, 5 or 3, 4.

[0052] The gears 26 - 32 can be used to achieve a transmission ratio for the driven shaft 33 (which is located in the center of the ring gear in Figure 4 ). Thereby, a very short transmission unit can be achieved.

[0053] In Figure 4 the mechanical coupling of the four sub-motors is achieved by means of a ring gear. In this design, the direction of rotation of the adjacent rotors is reversed without an intermediate gear, but with an external tooth part and an internal tooth part. The two tooth parts can be achieved by a combination of an externally meshing external tooth ring and an internally meshing internal gear, or alternatively can be achieved by a tooth ring 34 meshing on both sides (see Figure 4 ). The advantage is that the intermediate wheel for reversing the direction of rotation (including its support part and additional contact parts for introducing the torque into the central wheel) can be omitted. Due to the different radii of the external tooth part and the internal tooth part of the tooth ring 34, it is shown that the gears 35 - 38 associated with the sub-motors 2 - 5 have different radii, where this illustration is merely schematic and the scale is not to true scale.

[0054] Figure 5 With Figure 3They are very similar, where the two intermediate gears 31, 32 are replaced by a common intermediate gear 39. In this design, the reverse rotation direction of the rotor is generated by the intermediate gear 39, so that only a single central (tooth) gear 26 for adding torques is required. Thus, an internally meshing gear of a rotation direction group can be omitted, which means a certain manufacturing cost in terms of manufacturing technology. Here, this figure should also be understood as being roughly schematic; those skilled in the art adapt the radii of the gears 27 - 30 and 39 to the conditions and especially to the expected relationship of the rotational speeds of the rotors 2 - 5.

[0055] In a particular design, the relative angle between two counter - rotating rotation direction groups (i.e., using rotors rotating in opposite directions) can be changed by a suitable mechanical device. For example, Figures 3 - 5 the fixedly connected gears 29, 30 in [reference] can have (internally known) helical teeth, and the gears 29, 30 are axially moved by a mechanical device that enables the gears 29, 30 to axially move relative to the meshing (planetary) gears 31, 32, 34, 39. By the axial movement, due to the helical teeth, the relative angle between the two rotation direction groups rotates. Thus, the two rotation direction groups are rotated relative to each other, and for example, in the case of a permanently magnet - excited rotor, in this way, a geometrically induced magnetic field weakening can be achieved without the technically common stator current component for weakening the field. Therefore, for example, a permanent - magnet synchronous drive can be achieved during rotation using any voltage, i.e., also using zero voltage. Through this possibility of axial movement, other functions can also be further additionally achieved, such as a parking brake function, a safety function "zero clamping voltage", etc. The advantage of axial movement is that the magnetic flux linkage in the coil caused by torsion can be at least partially eliminated, so that the induced voltage can be reduced at the same rotational speed and approximately become zero when the torsion is appropriately large. Thus, on the one hand, as an alternative to electric - field weakening, mechanical - field weakening can also be achieved, and on the other hand, a very safe state of the rotating electric machine can be achieved, for example, in the case of a converter failure.

[0056] In Figures 6A to 6DThe same segment of the motor system 1 is shown at different phases. This segment shows two adjacent sub-motors 40, 41, which are electromagnetically coupled by exactly two core columns 42, 43 and have the same direction of rotation 44. This is achieved by the fact that the rotors 45, 46 have different numbers of poles. The first rotor 45 is bipolar and the second rotor 46 is quadrupolar. These poles are denoted in the drawing by the letters "N" and "S". For an understanding of the electromagnetic coupling, the magnetic flux is schematically drawn with arrows and integer magnetic flux units F. The two sub-motors 40, 41 shown are electromagnetically coupled via the core columns 47, 48 respectively to other sub-motors not shown.

[0057] As shown in Figures 6A to 6D the rotational speed of the bipolar rotor 45 is twice that of the quadrupolar rotor 46. On the other hand, the overall magnetism of the bipolar rotor 45 is only half that of the quadrupolar rotor 46 (i.e., when all the magnetic flux units are added together). Between each Figures 6A to 6D the bipolar rotor 45 rotates 60° in the clockwise direction, while the quadrupolar rotor 46 rotates only 30° in the same direction of rotation 44. Thus, Figures 6A to 6D shows the rotors 45, 46 rotating 180° and 90°. The magnetic flux units drawn in the core columns 42, 43 are generated by the poles of the rotors 45, 46 adjacent to the pole shoes, where, in many cases, these poles partly close the field lines via the air gap. In the image of the rotating traveling wave in the air gap, the same direction of rotation of the two rotors can be understood as the opposite movement of the fundamental harmonic and the second harmonic of the rotating field.

[0058] In Figure 7 the mechanical coupling using four gears 49 - 52 is shown, which are associated, for example, with the sub-motors 2 - 5 according to Figure 2B . The gears 49 - 52 are mechanically coupled to each other using a rack 53. Thus, when the sub-motors run along the shown directions of rotation 22, 23 (see Figure 2B ), the rack 53 performs a linear movement in the translational direction 54.

Claims

1. An electric motor system (1), said electric motor system having at least four, an even number of electromagnetically coupled sub - motors (2 - 5), said sub - motors being mechanically coupled by a transmission, said sub - motors generating a rotating field, each sub - motor having a common magnetic section and a common coil (16 - 21) with two adjacent sub - motors, wherein, Each sub - motor is electromagnetically coupled to two adjacent sub - motors. It is characterized in that at least two adjacent sub - motors (2, 3) have the same rotation direction (22).

2. The electric motor system (1) according to claim 1, characterized in that, The motor system (1) has at least four sub - motors (2 - 5), wherein one of the adjacent sub - motors of the sub - motors has a rotation direction opposite thereto, and the other of the adjacent sub - motors of the sub - motors has a rotation direction the same as it.

3. The electric motor system (1) according to claim 1, characterized in that, At least one sub - motor (2) is electromagnetically coupled to an adjacent sub - motor (3) with the same rotation direction (22) by exactly one core column (10).

4. The electric motor system (1) according to claim 2 or 3, characterized in that, At least one sub - motor (3) is electromagnetically coupled to an adjacent sub - motor (4) with an opposite rotation direction (23) by exactly two core columns (11, 12).

5. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, At least two adjacent sub - motors (40, 41) with the same rotation direction (44) have rotors (45, 46) with different numbers of poles.

6. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The coils (16 - 21) of at least two adjacent sub - motors (2 - 5) are connected into a three - circuit winding system.

7. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The coils (16 - 21) of all mechanically and electromagnetically coupled sub - motors are connected into a three - circuit winding system.

8. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The rotor (6) of at least one sub - motor in the sub - motors (2) is only bipolar or only quadrupolar.

9. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The mechanical coupling of the sub - motors (2 - 5) is defined by a transmission function that simultaneously defines the transmission ratio of the rotor speed to the transmission output speed.

10. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The mechanical coupling of the sub - motors (2 - 5) is configured to perform a linear motion.

11. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The average angular positions of at least two sub - motors (2 - 5) are mechanically changeable relative to each other during operation.

12. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, The average angular positions of all the sub - motors (2 - 5) are mechanically changeable relative to each other during operation.

13. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, At least a part of the coils (16 - 21) of the stator is cooled.

14. The electric motor system (1) according to any one of claims 1 to 3, characterized in that, At least a part of the core columns (10 - 15) of the stator carrying the coils has a magnetically preferred - direction permeable material.

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