CN219554799U - Integrated stator and synchronous parallel integrated motor - Google Patents

Abstract

The present disclosure relates to an integrated stator and synchronous parallel integrated motor. The integrated stator has at least one symmetry axis and a plurality of stator parts symmetrically arranged, each of the plurality of stator parts comprises: a stator yoke having an incomplete annular form; the cavity is arranged in the stator yoke; stator teeth extending from an inner wall of the stator yoke toward a center of the cavity; the winding groove is arranged between two adjacent stator teeth along the inner wall of the stator yoke; and concentrated windings each disposed in the winding slots and wound around a corresponding stator tooth, wherein a common stator tooth is disposed at a connection region of two different stator sections symmetrically disposed about one symmetry axis, the common stator tooth being symmetrically disposed about the one symmetry axis, the common stator tooth including first and second arcuate surfaces, the first arcuate surface having the same radius of curvature as the arcuate surface of the stator tooth of the first stator section, the second arcuate surface having the same radius of curvature as the arcuate surface of the stator tooth of the second stator section.

Description

Integrated stator and synchronous parallel integrated motor

Technical Field

The present disclosure relates to an integrated stator and a synchronous parallel integrated motor including the same.

Background

The double screw pump pumps liquid by using two screw shafts which are meshed with each other and are not contacted with each other, and the liquid is transferred to a cavity in the middle of the pump body along with the rotation of the screw shafts and is mixed together, so that the purpose of pump conveying is realized. The screw shaft of a conventional twin-screw pump is divided into a driving shaft driven by an electrode and a driven shaft driven by the driving shaft through a gear. Such driving methods have problems such as relatively high maintenance cost of gears, large vibration noise, leakage of lubricating oil or fuel, and unsatisfactory effects of synchronous gears.

In view of the above, a twin-rotor synchronous parallel conjoined motor is currently available to drive a twin-screw pump synchronously. The twin-rotor synchronous parallel conjoined motor generally comprises a conjoined stator and two rotors, wherein the two rotors respectively drive two screw shafts of the twin-screw pump. Therefore, the double-rotor synchronous parallel connected motor can ensure synchronous parallel of two screw shafts, eliminates equipment such as a transmission gear and the like, improves the system efficiency, and reduces the requirements on sealing.

However, in the existing preparation process of the double-rotor synchronous parallel conjoined motor, the following problems also exist: (1) Distributed windings are usually arranged in stator slots of the conjoined stator, but the distributed winding wire ends are high, large in size and high in cost; (2) The manufacturing method of the conjoined stator comprises the steps of firstly stacking silicon steel punching sheets into a cylinder shape through a punch press, respectively cutting two cylindrical stators to form stator cores with certain angles, arranging and connecting the left stator core and the right stator core together in parallel, filling the stators up and down and flattening the connection, thereby forming the conjoined stator, and the manufacturing method is complex, high in cost and has eddy current loss; (3) The manufacturing method of the rotor comprises the steps of firstly stacking silicon steel punched sheets into a cylinder shape through a punch press, reserving slots in the silicon steel punched sheets, and then transferring the pre-magnetized permanent magnets into the slots.

Disclosure of Invention

Therefore, an object of the present disclosure is to provide a one-piece stator and a synchronous and parallel one-piece motor including the same, which realizes de-ironing, reduction of eddy current loss, improvement of magnetic permeability, and improvement of torque, has a simple structure, and is low in cost, and can realize synchronous and parallel rotation of two rotors and synchronous and reverse rotation.

The above object is achieved by a one-piece stator and a synchronous parallel one-piece motor as described below.

The present disclosure provides a one-piece stator for a synchronous parallel one-piece motor, the one-piece stator having at least one axis of symmetry and a plurality of stator portions disposed symmetrically about the axis of symmetry, the plurality of stator portions each comprising:

a stator yoke having an incomplete annular form;

the cavity is arranged in the stator yoke;

a stator tooth extending from an inner wall of the stator yoke toward a center of the cavity;

the winding grooves are arranged between two adjacent stator teeth along the inner wall of the stator yoke; and

centralized windings which are respectively arranged in the winding slots and are wound with corresponding stator teeth,

wherein a common stator tooth is provided at a connection region of two different stator parts symmetrically arranged about one of the at least one symmetry axis, said common stator tooth being symmetrically arranged about said one symmetry axis,

the common stator tooth includes a first arcuate surface having the same radius of curvature as the arcuate surface of the stator tooth of a first one of the two different stator sections and a second arcuate surface having the same radius of curvature as the arcuate surface of the stator tooth of a second one of the two different stator sections.

In one embodiment, the plurality of stator portions are integrally formed with ferrite powder and a binder.

In an embodiment, each of the plurality of stator portions further includes a magnet slot, the magnet slot being disposed in the stator teeth, and a soft magnet being disposed within the magnet slot.

In an embodiment, further magnet slots are provided in the common stator teeth, the further magnet slots having soft magnets disposed therein.

In one embodiment, the common stator teeth are provided with virtual slots on both sides and no windings are provided on the common stator teeth.

In an embodiment, the soft-magnetic bodies are oriented in a radial direction of the respective stator part.

In one embodiment, the binder is epoxy resin or polyurethane, and the mass ratio is 1% to 10%.

In an embodiment, the side edges of the magnet slots are a first distance from the side edges of the respective stator teeth and the radially inner edges of the magnet slots are a second distance from the arcuate surface of the respective stator teeth, the first distance being at least 0.5mm and the second distance being at least 0.5mm.

In one embodiment, the one-piece stator has two stator parts arranged symmetrically with respect to a first axis of symmetry, on which the connection regions of the two stator parts are arranged.

In an embodiment, the integrated stator further has two further stator parts arranged symmetrically with respect to the first symmetry axis, the two further stator parts being arranged symmetrically with respect to a second symmetry axis perpendicular to the first symmetry axis, the connection areas of the two further stator parts with the two further stator parts being arranged on the second symmetry axis.

The present disclosure also provides a synchronous parallel conjoined motor, comprising:

a one-piece stator as described above; and

and a plurality of rotors disposed within the cavities of the respective stator portions.

In one embodiment, the rotor is integrally formed with the plastic magnetic material or with the magnetic powder and the binder.

In one embodiment, the rotor includes a plurality of magnets, adjacent ones of the plurality of magnets having opposite magnetic properties.

In an embodiment, the plurality of magnets of the rotor of the first stator part and the plurality of magnets of the rotor of the second stator part are symmetrically arranged about the one symmetry axis, but are magnetically opposite.

Embodiments of the present disclosure have the following advantages. Through ferrite powder and binder integrated into one piece, the integrated stator has realized the de-ironing, has reduced eddy current loss, has reduced the cost, is more suitable for large-scale industrial production. Through set up the groove and install soft magnetic body in stator tooth and public stator tooth, make disjunctor formula stator have higher saturation magnetic density and lower core loss in tooth portion, reduced stator core's volume and size, improved the electric energy utilization ratio, reduced maximum output torque current, promoted motor efficiency. Through reducing the iron loss, the internal temperature rise of the motor can be reduced, and the permanent magnet demagnetization caused by the overhigh internal temperature of the motor is prevented. Through set up virtual groove and arc surface in public stator tooth both sides, can guarantee the integrality of whole motor magnetic circuit, further reduction core loss does benefit to the rotor operation. By using concentrated windings, the integrated stator reduces cost and can provide greater torque. Through using plastic magnetic material or through magnetic powder and binder integrated into one piece, the rotor has realized the de-ferrization, and the cost is reduced and makes rotor waveform uniformity better.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments of the present disclosure will be briefly described below. Wherein the drawings are designed solely to illustrate some embodiments of the disclosure and not to limit all embodiments of the disclosure thereto. In the accompanying drawings:

FIG. 1 illustrates a cross-sectional view of a one-piece stator according to one embodiment of the present disclosure;

FIG. 2 illustrates a cross-sectional view of a portion of a synchronous parallel conjoined motor according to an embodiment of the present disclosure;

FIG. 3 illustrates a schematic view of stator teeth of a one-piece stator according to one embodiment of the present disclosure;

FIG. 4 illustrates a cross-sectional view of a portion of a synchronous parallel conjoined motor according to another embodiment of the present disclosure; and

fig. 5a and 5b illustrate a distribution pattern of magnets of a rotor of a synchronous parallel conjoined motor according to another embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the technical solutions of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of specific embodiments of the present disclosure. Like reference numerals in the drawings denote like parts. It should be noted that the described embodiments are some, but not all embodiments of the present disclosure. All other embodiments, which can be made by one of ordinary skill in the art without the need for inventive faculty, are within the scope of the present disclosure, based on the described embodiments of the present disclosure.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a" or "an" and the like do not necessarily denote a limitation of quantity. The word "comprising," "comprising," or "having" and the like means that elements or items preceding the word are meant to be encompassed by the element or item recited following the word and equivalents thereof, without excluding other elements or items. The terms "connected" or "connected" and the like are not limited to the physical or mechanical connection or communication shown in the drawings, but may include connection or communication equivalent thereto, whether direct or indirect. "upper", "lower", "left", "right", "horizontal", "vertical", etc. are only used to indicate a relative positional relationship, which may be changed accordingly when the absolute position of the object to be described is changed.

As shown in fig. 1 to 4, a synchronous parallel conjoined motor according to the present disclosure includes a conjoined stator and a rotor disposed within a cavity inside the conjoined stator.

As shown in fig. 1 to 4, the integrated stator has at least one symmetry axis and a plurality of stator parts 1 arranged symmetrically with respect to said symmetry axis. The stator parts 1 each comprise a stator yoke 2, a cavity 3, stator teeth 4 and winding slots 5. In addition, the stator parts each also comprise a magnet slot 6. The figures herein only schematically show a cross section of a synchronous parallel conjoined motor, with the conjoined stator and rotor extending in a direction perpendicular to the plane of the figure.

The integrated stator shown in fig. 1 to 2 has two stator parts 1 arranged symmetrically about an axis of symmetry, namely a first axis of symmetry a, and the integrated stator shown in fig. 4 has a total of four stator parts arranged symmetrically about two axes of symmetry, namely a first axis of symmetry a and a second axis of symmetry B, respectively. The integrated stator of fig. 1 to 2 is furthermore arranged symmetrically with respect to a further axis of symmetry a' which passes through the centre of the rotation axis of the rotor 20 arranged in the cavity of the stator part 1. The integrated stator in fig. 1 to 2 can be said to have a structure symmetrical in the left-right direction and in the up-down direction. The integrated stator in fig. 4 also has a structure symmetrical from left to right and up and down.

The stator yoke 2 has an incomplete annular form, such as an annular form lacking an arcuate segment in fig. 1. The cavities 3 are provided in the stator yoke 2 and each stator part 1 has its own cavity. The stator teeth 4 extend from the inner wall of the stator yoke 2 towards the centre of the cavity 3, for example having a T-shaped cross section, and are evenly distributed over the inner wall of the stator yoke 2. The winding slots 5 are provided between adjacent two of the stator teeth 4 along the inner wall of the stator yoke 2 and are uniformly distributed on the inner wall of the stator yoke 2. The magnet slots 6 are arranged in the stator teeth 4 and are hollow structures extending along the extending direction of the integrated stator, and soft magnets can be arranged in the magnet slots 6. The number of stator teeth 4 in each stator part 1 is the same and the number of winding slots 5, magnet slots 6 is also the same due to the symmetrical arrangement from top to bottom and from side to side.

Unlike a conventional stator made of silicon steel, the plurality of stator portions 1 of the integrated stator of the present disclosure are integrally formed by ferrite powder and a binder. Specifically, epoxy resin or polyurethane is mixed into ferrite powder as a binder, and the conjoined stator is formed at one time by adopting a powder metallurgy preparation method and then is put into a high-temperature oven for hardening. The mass ratio of the epoxy resin or polyurethane as the binder is, for example, 1% to 10%. The ferrite powder is mainly soft magnetic ferrite, manganese zinc ferrite or nickel zinc ferrite. The mode avoids stacking, cutting and splicing processes in the conventional preparation process, and simplifies the manufacturing process, thereby being beneficial to large-scale industrial production of the integrated stator. In addition, the mode ensures that the whole integrated stator core has no silicon steel sheet, thereby realizing de-ironing and reducing the cost.

The soft magnetic body in the magnet groove 6 is, for example, a magnetic stripe composed of a soft magnetic material, and is mounted in the magnet groove 6 by a inlay process. The soft-magnetic body has been previously oriented in the radial direction of the respective stator part 1 before installation, either in the direction of the stator yoke 2 to the stator teeth 4 or in the direction of the stator teeth 4 to the stator yoke 2. The radial orientation of the strips provides the best magnetic performance of the strips in the radial direction and a higher saturation flux density on the magnetic flux path of the stator teeth. For example, the stator yoke 2 of the left and right connected stator parts 1 in fig. 1 to 2 is unoriented, and the stator teeth 4 are oriented, so that the stator teeth 4 have higher saturation magnetic flux density and lower iron loss, and therefore, the stator teeth can be designed to be smaller, the volume and size of the stator can be reduced, the electric energy utilization rate can be improved, the maximum output torque current can be reduced, and the motor efficiency can be improved. In addition, the iron loss is reduced, so that the internal temperature rise of the motor can be reduced, and the permanent magnet is prevented from demagnetizing due to the overhigh internal temperature of the motor.

The soft magnetic body is, for example, manganese zinc ferrite or nickel zinc ferrite, and the stator manufactured using this material is unoriented, but the magnetic stripe manufactured using this material is oriented when embedded in the magnet slot 5 having a rectangular hollowed-out structure.

As shown in fig. 1 to 4, a common stator tooth 7 is provided at the connection area of two different stator parts symmetrically arranged about one of the at least one symmetry axis described hereinbefore, said common stator tooth comprising a first arcuate surface 13 and a second arcuate surface 14. The first arcuate surface 13 has the same radius of curvature as the arcuate surfaces of the stator teeth of the first one 11 of the two different stator sections and the second arcuate surface 14 has the same radius of curvature as the arcuate surfaces of the stator teeth of the second one 12 of the two different stator sections. As shown in fig. 3, the arcuate surface of one stator tooth is denoted by 15 and has a radius of curvature corresponding to the profile of the respective rotor, in other words, to the outer contour of the respective rotor. By arranging the arc-shaped surfaces of the common stator teeth 7 in such a way that they can form a circumference together with the arc-shaped surfaces of the corresponding stator teeth 4, the magnetic conduction effect of the arc-shaped surfaces of the common stator teeth 7 is better than that of air, so that the iron loss can be further reduced, and the rotor operation is facilitated.

In fig. 1 to 2, the one-piece stator has two stator parts arranged symmetrically about a first axis of symmetry a, on which the connection regions of the two stator parts are arranged. As shown in fig. 2, the left stator part may be a first stator part 11 and the right stator part may be a second stator part 12.

In fig. 4, in addition to the two stator parts described above, the one-piece stator has two further stator parts arranged symmetrically with respect to the first axis of symmetry a, the two stator parts being arranged symmetrically with respect to the two further stator parts with respect to a second axis of symmetry B perpendicular to the first axis of symmetry a, the connection areas of the two stator parts with the two further stator parts being arranged on the second axis of symmetry B. As shown in fig. 4, if the stator part of the upper left corner may be the first stator part 11, the stator part of the upper right corner or the stator part of the lower left corner may be the second stator part 12.

The common stator tooth 7 is arranged symmetrically with respect to the symmetry axis of the two different stator parts described above and in which further magnet slots 8 are arranged. Similar to the magnet slots 6 described above, the soft magnets described above, which are oriented in the radial direction of the stator, are also provided in the additional magnet slots 8, thereby further reducing the core loss. The iron loss is further reduced, so that the internal temperature rise of the motor can be further reduced, and the permanent magnet is further prevented from demagnetizing due to the fact that the internal temperature of the motor is too high. The further magnet slots 8 are also symmetrical about said symmetry axis, thus allowing a higher saturation magnet density on the magnetic flux path of the entire stator tooth.

As shown in fig. 3, the side edges of the magnet slots 6 described above are at a first distance, indicated for example by d1, from the side edges of the respective stator teeth, and the radially inner edges of the magnet slots 6 are at a second distance, indicated for example by d2, from the arcuate surfaces 15 of the respective stator teeth. Likewise, the side edges of the further magnet slots 8 may also be at a first distance from the side edges of the respective common stator teeth 7. The left and right side edges of the magnet slot 6 in fig. 3 are each a first distance from the corresponding stator tooth side edge. The first distance d1 is at least 0.5mm, for example, so as to ensure a certain mechanical strength of the stator teeth and avoid breakage of the stator teeth during winding. The second distance described above is for example at least 0.5mm. Further, the radially outer edge of the magnet slot 6 does not exceed the radially inner edge of the stator yoke 2. The radially inner or outer edge is described herein with respect to the radial center of the stator or rotor, as shown in fig. 3, the radially outer edge of the magnet slot 6 being the upper edge in the drawing and the radially inner edge being the lower edge in the drawing.

As shown in fig. 2 and 4, both sides of the common stator teeth 7 are provided with virtual slots 16, and no windings are provided on the common stator teeth 7. A dashed slot is used herein to denote that no winding is provided in the slot. The virtual slot can ensure the integrity of the magnetic circuit of the whole motor. As shown in fig. 2 and 4, the plurality of stator portions 1 each further comprises a concentrated winding 9, said concentrated windings 9 each being arranged in a winding slot 5 and wound around a respective stator tooth 4. Specifically, a three-phase winding structure with concentrated windings is adopted in the winding slots 5 of the integrated stator, and a certain number of virtual slots are reserved in the integrated stator, and no windings are arranged in the virtual slots, so that the current direction in each slot is the same when three-phase current is passed. The integrated stator of the present disclosure employs concentrated windings, which can be wound by a winding machine. The centralized winding wire end is low, small in size, small in resistance loss, simple in structure and low in cost, and meanwhile, the winding wire end has larger torque due to trapezoidal counter electromotive force.

In the synchronous parallel conjoined motor of the present disclosure, the conjoined stator is as described above. As shown in fig. 2 and 4, the motor further comprises a plurality of rotors 20, which are arranged in the cavities 3 of the respective stator portions 1.

Unlike conventional rotors made of silicon steel, the rotor 20 of the motor of the present disclosure is integrally formed by a plastic magnetic material or by magnetic powder and a binder. For example, the rotor 20 is manufactured by one-shot molding through an injection molding process using a plastic magnetic material. Alternatively, the rotor 20 is manufactured by injection molding one-shot using thermosetting resin bonded magnetic powder. The rotor may be oriented during the above-described preparation process. Compared with the conventional technology that the rotor is formed by stamping and stacking unoriented silicon steel sheets, and then permanent magnets are inlaid into the rotor or attached to the outer circumferential surface of the rotor, the rotor disclosed by the utility model can simplify the process flow, realize no iron of a rotor core, has low cost and better waveform consistency of the rotor. The rotor 20 provided in one stator part 1 may comprise a plurality of magnets 25 evenly distributed along an annular shape and concentric with the annular stator yoke 2. The magnets 25 in one rotor 20 have opposite magnetic properties, i.e. adjacent magnets of the same rotor have N-poles and S-poles alternately arranged.

The plurality of magnets 25 of the rotor 20 of the first one 11 of the two different stator parts, which are symmetrically arranged about one of the at least one symmetry axis, are symmetrically arranged about said one symmetry axis, but magnetically opposite to the plurality of magnets 25 of the rotor 20 of the second one 12 of the two different stator parts. For example, as shown in fig. 2, after the installation is completed, the rotor of the first stator part 11 and the rotor of the second stator part 12 are arranged mirror symmetrically about the first symmetry axis a, but with opposite polarities of the magnets. As shown in fig. 4, after the installation is completed, the upper left-hand rotor 21 and the upper right-hand rotor 22 are arranged mirror symmetrically about the first symmetry axis a, but with the magnets of opposite polarity; the upper left-hand rotor 21 and the lower left-hand rotor 23 are arranged mirror-symmetrically with respect to the second symmetry axis B, but with opposite polarities of the magnets; the lower left-hand rotor 23 and the small right-hand rotor 24 are arranged mirror-symmetrically with respect to the first symmetry axis a, but with opposite polarities of the magnets; the upper right-hand rotor 22 and the lower right-hand rotor 24 are arranged mirror-symmetrically with respect to the second axis of symmetry B, but with opposite magnet polarities.

Furthermore, the rotors provided in the cavities of the different stator parts are not in direct contact, an air gap 17 being present between the rotors. The air gap ensures that different rotors are not in direct contact, and the air gap magnetic field intensity between the rotors is adjusted.

In the motor shown in fig. 2, when current is applied to the concentrated winding 9, the rotor of the first stator portion 11 and the rotor of the second stator portion 12 are arranged in mirror symmetry and have opposite polarities, and the rotor of the first stator portion 11 and the rotor of the second stator portion 12 are rotated in opposite directions synchronously, so that the opposite rotation is realized.

The four rotors of the motor of fig. 4 may have different pole pairs. As shown in fig. 5a, the rotor has 10 pole pairs. As shown in fig. 5b, the rotor has 8 pole pairs. The choice of pole pair numbers depends on the particular application.

The integrated stator realizes the de-ironing, the reduction of eddy current loss, the improvement of magnetic permeability and the improvement of torque, has simple structure and low cost, and the synchronous parallel integrated motor can realize the synchronous parallel rotation of two rotors and can realize synchronous reverse rotation.

Furthermore, each feature disclosed above is not limited to the combination of the disclosed features with other features, and other combinations between features may be made by those skilled in the art in view of the disclosure for the purpose of this disclosure.

Claims (11)

1. A one-piece stator for a synchronous parallel one-piece motor, characterized in that it has at least one axis of symmetry and a plurality of stator portions (1) arranged symmetrically with respect to the axis of symmetry, each of the plurality of stator portions comprising:

a stator yoke (2) having an incomplete annular form;

a cavity (3) disposed within the stator yoke;

a stator tooth (4) extending from an inner wall of the stator yoke towards a center of the cavity;

a winding groove (5) arranged between two adjacent stator teeth along the inner wall of the stator yoke; and

centralized windings (9) which are respectively arranged in the winding slots (5) and are wound with corresponding stator teeth,

wherein a common stator tooth (7) is provided at the connection area of two different stator parts symmetrically arranged about one of the at least one symmetry axis, said common stator tooth being symmetrically arranged about said one symmetry axis,

the common stator tooth comprises a first arcuate surface (13) and a second arcuate surface (14), the first arcuate surface (13) having the same radius of curvature as the arcuate surface of the stator tooth of the first one (11) of the two different stator portions, the second arcuate surface (14) having the same radius of curvature as the arcuate surface of the stator tooth of the second one (12) of the two different stator portions.

2. The integrated stator according to claim 1, characterized in that the plurality of stator parts each further comprises a magnet slot (6), which is arranged in the stator teeth and in which a soft magnet is arranged.

3. Integrated stator according to claim 2, characterized in that further magnet slots (8) are provided in the common stator teeth, in which further magnet slots soft magnets are provided.

4. A one-piece stator according to claim 3, characterized in that the common stator teeth are provided with virtual slots (16) on both sides and no windings are provided on the common stator teeth.

5. A one-piece stator according to claim 3, characterized in that the soft-magnetic bodies are oriented in the radial direction of the respective stator part (1).

6. The integrated stator according to claim 2, characterized in that the side edges of the magnet slots (6) are at a first distance from the side edges of the respective stator teeth and the radially inner edges of the magnet slots (6) are at a second distance from the arcuate surface of the respective stator teeth, the first distance being at least 0.5mm and the second distance being at least 0.5mm.

7. The one-piece stator according to claim 1, characterized in that it has two stator parts arranged symmetrically with respect to a first axis of symmetry (a), on which first axis of symmetry (a) a connection area of the two stator parts is arranged.

8. The integrated stator according to claim 7, characterized in that it further has two further stator parts arranged symmetrically with respect to the first symmetry axis (a), which are arranged symmetrically with respect to a second symmetry axis (B) perpendicular to the first symmetry axis (a), on which second symmetry axis (B) the connection areas of which are arranged.

9. A synchronous parallel conjoined motor, characterized in that it comprises:

the integrated stator of any one of claims 1 to 8; and

a plurality of rotors (20) are disposed within the cavities of the respective stator sections.

10. The synchronous, parallel, conjoined electric machine as claimed in claim 9, wherein the rotor comprises a plurality of magnets (25), adjacent ones of the plurality of magnets being of opposite magnetic polarity.

11. Synchronous parallel conjoined motor according to claim 10, wherein the magnets of the rotor of the first stator part (11) are symmetrically arranged with respect to the one symmetry axis, but of opposite magnetism, to the magnets of the rotor of the second stator part (12).