Dual rotor radial flux motor

Abstract

This invention relates to a dual-rotor radial flux motor, particularly for use in hub drive systems, comprising: a stator having a stator core and a torsion-resistant rigid winding therein, the conductor rods of the torsion-resistant rigid winding extending helically in a first rotational direction radially inside the stator and helically in a second rotational direction radially outside the stator; and dual rotors having an inner rotor and an outer rotor and a common central axis, wherein the inner and outer rotors have corresponding annular bodies designed to conduct flux, and a plurality of corresponding permanent magnets fixed to the annular bodies, each permanent magnet having a cross-section paired with a specific corner segment of the annular body, the permanent magnets being designed and disposed on the corresponding annular bodies such that the axial path of the specific corner segment is offset circumferentially, so that the permanent magnets generate a magnetic field extending obliquely relative to the central axis. The magnetic field of the inner rotor extends obliquely in a first direction oriented towards the first rotational direction, and the magnetic field of the outer rotor extends obliquely in a second direction oriented towards the second rotational direction.

Description

Technical Field

[0001] This invention relates to a dual-rotor radial flux motor, particularly for use in hub drive systems. Background Technology

[0002] Compared to conventional motors with only one rotor, motors with a stator and two rotors that rotate together, known as dual-rotor motors (also called multi-rotor, two-rotor, etc.), can improve the torque density and efficiency of electric drive devices. This is likely due to the fact that, especially in so-called "yokeless" designs, a back iron is not required in the stator, thus significantly reducing magnetic losses. Furthermore, in the case of two rotors, there is essentially more space available for field-excitation magnets (in the case of permanent magnet synchronous motors, PSMs) or conductor materials (in the case of induction motors, IMs, or electrically excited synchronous motors, ESMs). Based on the direction of the magnetic field lines in the air gap, these motors can be divided into two categories: axial flux-carrying type (the magnetic field lines are parallel to the axis of rotation, i.e., axial flux motors) and radial flux-carrying type (the magnetic field lines are in the radial direction in the air gap, i.e., radial flux motors).

[0003] Dual-rotor axial flux motors are described, for example, in DE 10 2015 226 105 A1 and DE 10 2013 206593A1. They are characterized by high torque and high power density, but their manufacturing cost is high because the stator core must be stamped using powder metallurgy or have a very complex geometry. Therefore, to date, these motors have not entered mass production and are only used in niche fields with high power density requirements, such as racing and aerospace. Furthermore, the mechanical fastening design of the stator windings only allows for the use of single-tooth windings, which have corresponding disadvantages in terms of noise excitation.

[0004] In contrast, in the case of a dual-rotor radial flux motor, established manufacturing methods for the windings and laminated cores can be used, which are suitable for mass production. However, significant and largely unresolved technical challenges exist in supporting the torque generated in the stator core. Due to the presence of internal and external rotating components, the laminated stator core cannot be mounted (e.g., pressed, tightened, or adhered) in a fixed housing as is typically the case. Therefore, the torque is directed to and supported at the axial ends of the laminated stator core or stator windings. Various methods have been proposed in this regard, but all have significant drawbacks in terms of functionality and / or cost.

[0005] EP 1 879 283 B1 describes a method for designing stator windings as so-called yoke windings. In this case, the inner and outer diameters of the toroidal laminated stator core have grooves, between which a tangentially effective back iron (also called a stator yoke) is positioned. In this configuration, the forward and return conductors of each winding strand are guided within the grooves, laid radially one after the other, and wound around the yoke. The stator yoke is axially accessible between the winding strands and can be fixed to the housing, for example, by means of axial screw connections (as described in JP 2018 082 600). The axial compression of the screws ensures both the torsional stiffness of the laminated core and torque support at the axial ends. The north and south poles of the rotor magnetic field are positioned opposite each other. A disadvantage of this design is that the magnetic flux must be transmitted entirely through the return yoke located between the stator slots. On the one hand, this results in increased weight of the laminated stator core and significantly increased iron losses. The magnetic field lines of the two rotor fluxes are closed by the back iron in the laminated stator core, generating iron losses at this location. Furthermore, all individual coils of the yoke winding must be interconnected in parallel or series within the winding head region, which in turn leads to a conflict between installation space and torque support. However, the yoke-wound winding allows for direct mechanical contact with the laminated stator core.

[0006] If the magnetization direction of magnets laid radially in the same direction, one after another, is the same as the current supply direction of conductors laid radially in trenches, one after another, considerable weight and loss savings can be achieved. In this case, the back iron in the stator can be omitted, resulting in a so-called "yokeless" dual-rotor motor with distributed windings. The magnetic field lines are closed on the rotor. No back iron is needed in the stator, resulting in very low weight and iron losses in this type of motor. However, distributed windings do not allow direct mechanical contact with the stacked stator cores for torque support. For example, WO2004 / 004098 A1 describes a yokeless embodiment with distributed windings.

[0007] Regarding axial support, various auxiliary structures for torque support have been proposed in the prior art, such as those described in DE 10 2010055 030A1 or US 7,557,486 B2. The problem here is that conductive and / or magnetic metals are not allowed to protrude into the flux transmission region, or are only allowed to protrude within a very limited area, which severely restricts material selection and geometry design. Conversely, composite material components, adhesives, and / or casting materials can also be used in the flux transmission region. However, such materials are difficult to meet stringent requirements regarding temperature stability and mechanical strength. Summary of the Invention

[0008] Against this backdrop, the object of the present invention is to provide an improved dual-rotor radial flux motor.

[0009] According to the present invention, this objective is achieved by a dual-rotor radial flux motor having the features described in claim 1.

[0010] Therefore, the following is provided:

[0011] A dual-rotor radial flux motor, particularly for use in hub drive systems, includes a stator having a stator core and a torsion-resistant rigid winding housed within the stator core. The torsion-resistant rigid winding has conductors extending helically in a first rotational direction in the radial interior of the stator, and helically in a second rotational direction in the radial exterior of the stator. The motor also includes dual rotors having an inner rotor and an outer rotor with a common central axis. Each of the inner and outer rotors has an annular shape designed for flux transmission. The body comprises a plurality of permanent magnets fastened to the annular body in each case, each of the permanent magnets being assigned to a predetermined corner segment of the annular body within a cross-section, wherein the permanent magnets are formed and disposed on the respective annular body such that the predetermined corner segment is circumferentially displaced in an axial progression to generate a magnetic field that extends obliquely relative to the central axis, wherein the magnetic field of the inner rotor extends obliquely along a first direction oriented toward a first rotation direction, and the magnetic field of the outer rotor extends obliquely along a second direction oriented toward a second rotation direction.

[0012] A discovery that forms the basis of this invention lies in the fact that, in the case of a dual-rotor radial flux motor, magnetic field distortion can exist due to the axial variation of the magnetic field. The magnetic field has its full amplitude only at the axial center of the motor. The axial ends of the motor experience a reduction in the amplitude of the magnetic field.

[0013] Another discovery that forms the basis of this invention is the fact that magnetic field distortion causes a shift in the maximum magnetic field value, resulting in a decrease in torque.

[0014] The concept that forms the basis of this invention is to provide a specific combination of electric synchronous motors, the motor comprising: dual rotors, wherein the stator has a stator core and torsional rigid windings housed within the stator core for torque support; and permanent magnets disposed within the respective rotors, the permanent magnets being circumferentially displaced in an axial process to generate a tilted extended magnetic field.

[0015] The individual conductor rods of the anti-torsion winding are axially arranged along the helix of the stator slot and in a first and second rotational direction corresponding to the radially inner and radially outer stator slots, and are connected at the conductor ends. Preferably, for this purpose, an integral joint connection by fusion welding or brazing is provided. However, other connection techniques are also feasible. Preferably, two conductor rods are each connected at the end of the conductor rod, and all conductor rods together form such a rod structure. Thus, the winding is formed by conductor rods connected together, particularly in a rod structure. The rod structure formed by conductor rods is advantageously configured in a manner that is inherently torsionally rigid and designed to transmit torque about the central axis of the stator. Thus, the winding obtains its torsional stiffness on the one hand, and is additionally connected to the stator core in a form-fit manner on the other hand for torque support.

[0016] Furthermore, the conductor rods are designed to have a thickness sufficient to transmit power. In the case of hub motors, the thickness of the conductor rods can, for example, be in the range of several millimeters. In particular, they can be rods with a square profile having a side length of several millimeters.

[0017] The selected lead angle (also called the set angle) of the stator slots or the helix associated with them ensures the formation of conductor loops by connecting the introduced conductor rods. The angle of the conductor loops in the motor, i.e., the angle swept relative to the central axis, wraps around the rotor poles in each case. In this way, it becomes possible to manufacture the stator very simply, despite its functional integration, which is successfully implemented with few parts and relatively simple conventional connection techniques, and therefore with very few manufacturing steps.

[0018] A stator designed in this way can now be completed together with an innovative inner and outer rotor to form a motor according to the invention. The anti-torsional rigid winding comprises dividing the stator into radially inner and outer sections, wherein the conductor rods of the radially inner anti-torsional rigid winding are helically arranged along a first rotational direction, and the conductor rods of the radially outer anti-torsional rigid winding are helically arranged along the opposite second rotational direction. The continuous (tangential) displacement of the conductor rods by their axial position within the motor causes the magnetic field generated by the anti-torsional rigid winding to change by axial position within the motor. Therefore, the magnetic field has its maximum amplitude only at the axial center of the motor, where conductor rods with the same coil strands and the same current direction are positioned one above the other. Due to the basic geometry, the magnetic field amplitude decreases towards the two axial ends of the motor. The average value over the entire length is particularly important for the resulting flux linkage and motor torque.

[0019] In addition to the reduction in magnetic field amplitude, tangential magnetic field distortion is also generated at the axial end of the motor due to the rotational displacement of the conductor rods relative to each other, resulting in a tangential displacement of the maximum magnetic field value. In the case of a conventional permanent magnet configuration, this magnetic field distortion will lead to a reduction in torque because the permanent magnets in the rotor are no longer located in the optimal position for generating torque in every case.

[0020] Therefore, according to the invention, the torque reduction due to magnetic field distortion is offset by a novel permanent magnet matching arrangement. For this purpose, the permanent magnets of the respective rotors are circumferentially displaced during the axial progression, thereby generating a tilted magnetic field. The opposing tilted magnetic fields generated by the inner and outer rotors extend along two tilting directions, which correspond to the respective and opposite rotational directions of the conductor rods of the anti-torsional rigid winding. Advantageously, the innovative axial displacement of the permanent magnets in the circumferential direction has a positive effect on the generated torque, particularly enabling an increase in torque of up to 10% compared to a non-tilted configuration of the permanent magnets in the inner and outer rotors.

[0021] The rotor is preferably made of a soft magnetic solid material and has surface-mounted permanent magnets. In this case, the small upper field spectrum of the winding deformation and the distance between the solid material and the air gap ensured by the magnets prevent unacceptably large losses due to eddy currents within the rotor. This design also allows for relatively high efficiency in an advantageous manner, while the rotor can still be manufactured in a very cost-effective way.

[0022] The stator support, specifically engaged with the torsional rigid winding, is fixedly connected to the base, which serves as the motor mounting part, by a suitable method. For this purpose, a feasible embodiment provides an opening, such as a through hole, for a force-fit fastening device like a screw. Of course, additionally or alternatively, the use of form-fitting connecting devices and / or integrally bonded connecting devices is also feasible.

[0023] In particular, the present invention can be used advantageously in hub motors, especially in motor vehicles. According to the structure of the invention, due to functional integration, the weight of the dual-rotor radial flux motor can be reduced, and the torque density can be increased, which advantageously means a reduction in unsprung mass, particularly in the case of hub motors. Furthermore, according to the invention, a relatively short axial length can be achieved with a relatively large diameter, which is particularly advantageous in terms of torque support and mounting space within the wheel.

[0024] On the other hand, according to the invention, despite the extremely compact design, very high torque is also possible, especially high enough to directly drive the vehicle wheels without transmission. Therefore, transmission losses are avoided in a particularly advantageous manner, weight is further reduced, and exceptionally high advantages in terms of efficiency can be achieved.

[0025] Furthermore, for installation dimensions within the standard motor vehicle wheel rim size range, such high torque in the four-digit range is clearly sufficient, especially greater than 1000 Nm, preferably greater than 1500 Nm, and particularly preferably greater than 5000 Nm. This extends to the liability limits of standard highway tires and even allows for the replacement of rear axle wheel brakes with hub motors. Therefore, specific synergistic effects or functional integration can be achieved in the application of hub motors.

[0026] Advantageous embodiments and improvements will become clear from the further dependent claims and the description with reference to the accompanying drawings.

[0027] According to a preferred embodiment, the annular body is made of a solid material. The torsion-resistant rigid winding provides, for the first time, the possibility of designing the windings of a dual-rotor synchronous motor as distributed windings with a correspondingly small upper magnetic field spectrum. Only in this embodiment can the rotor be manufactured with a solid material, because the windings will only generate a small upper magnetic field and the resulting eddy currents in the rotor. Therefore, when manufacturing the inner and outer rotors made of soft magnetic solid materials, cost savings can be achieved due to simplified manufacturing, and high efficiency levels can be realized.

[0028] According to another embodiment, the permanent magnet is positioned at a predetermined helix angle relative to the axial direction of the central axis on the annular body. This allows the magnetic field generated by the permanent magnet to be oriented in a targeted or purposeful manner relative to the central axis of the annular body, thereby generating the desired tilted magnetic field. The helix angle can be freely adjusted, as it is primarily affected by the actual positioning and / or orientation of the permanent magnet. In this way, by selectively or purposefully adjusting the predetermined helix angle, torque reduction caused by magnetic field distortion can be advantageously counteracted.

[0029] According to another embodiment, each of the permanent magnets is divided into multiple axial segments. Each axial segment is assigned a corner segment, which is displaced by a set angle relative to adjacent axial segments about the central axis. The total helix angle generated about the central axis or circumferentially is determined according to the set angle, and particularly according to a multiple of the set angle. Furthermore, the axial segments can be oriented such that their edges are parallel to the central axis of the annular body. The number of axial segments and the set angle of each individual axial segment relative to each other are freely selectable. In this way, a dual-rotor radial flux motor is provided, which can be configured in conjunction with manufacturing costs and magnetic field optimization.

[0030] According to another embodiment, when each permanent magnet has a predetermined number of axial segments (n), the resulting total helix angle φ is determined based on a set angle θ using the relationship φ = n * θ. Since there is a simple mathematical relationship between the number of axial segments of each permanent magnet and the set angle, the various parameters of the rotor magnet arrangement of the dual-rotor radial flux motor according to the present invention can be calculated using a simple method and are easily implemented. Therefore, the dual-rotor radial flux motor can be easily adapted or designed to meet different requirements.

[0031] According to another embodiment, each permanent magnet is divided into two axial segments. In this way, a variation of a dual-rotor radial flux motor is provided according to the invention, which is simple to manufacture and therefore particularly advantageous in terms of manufacturing cost. Since the number of axial segments is still relatively small, the orientation and assembly of the segments are still relatively simple, but the torque achievable during operation is significantly increased.

[0032] According to another embodiment, the permanent magnet is oriented with its edge along a predetermined helix angle. Therefore, a dual-rotor radial flux motor is provided, which can also be adjusted and designed with an integral permanent magnet according to requirements related to the predetermined helix angle. If the permanent magnet has a planar surface, the inclined arrangement of the permanent magnet on the inner or outer circumferential surface of its respective annular body due to geometry results in a slight gap in cross-section between the permanent magnet and the body. In the case where the permanent magnets on the annular body are integrally bonded, this gap is preferably filled with an integral bonding medium. The aforementioned integral bonding can be constructed, for example, by a suitable adhesive.

[0033] According to another embodiment, the permanent magnet has an oblique parallelogram shape. The parallelogram-shaped permanent magnets similarly, and in particular, have the same total helix angle in the circumferential direction. In this way, due to the parallelogram shape, surface gaps or protrusions of the permanent magnet on the surface of the annular body can be avoided. This allows for optimal utilization of the surface of the annular body. Due to the arrangement of the parallelogram-shaped permanent magnets within or on the annular body, gaps are similarly created due to the geometry. However, in the case, for example, where the permanent magnets on the annular body are integrally bonded, these gaps can be filled by an integral bonding medium. The integral bonding can be constructed, for example, by a suitable adhesive.

[0034] According to another embodiment, the permanent magnet can also be formed as a rectangle, particularly a narrow rectangle. The corners of the permanent magnet can have relatively small free surfaces on the respective annular bodies, or protrude beyond the bodies along with the corners. Since the size of the permanent magnet, especially its width, is selectable, whether it flows out of the surface or protrudes can also be adjusted in this way. Therefore, a dual-rotor radial flux motor is provided, which can be designed in a simple manner according to requirements. In a further embodiment, further orientation of the permanent magnet is also possible, which will generate the desired tilted magnetic field.

[0035] According to one embodiment, the windings are designed to be torsionalally rigid, such that during operation of the dual-rotor radial flux motor, the torque acting on the stator core can be supported, in particular fully supported, by the torsionalally rigid windings on the support elements. In this way, all other types of force support devices, especially force support devices for the stator core, can be advantageously omitted.

[0036] According to another embodiment, the winding has a radially inner layer of helically arranged conductor rods inside the stator and a radially outer layer of conductor rods with reverse helical arrangements outside the stator. In this way, the rod structure is formed by the winding and has high torsional stiffness. Each of the radially inner and radially outer conductor rods describes a helix with opposite rotational directions or pitches. The angle between the helixes at the beginning and end of the conductor rods—sweeping relative to the stator's central axis—is specifically designed such that, in a dual-rotor radial flux motor, each rotor pole forms a conductor loop. Therefore, the sweep angle to be provided can be calculated based on the full rotation (2π or 360°) and the quotient of twice the number of pole pairs p.

[0037] According to one embodiment, the radial inner and radial outer layers of the winding each have the thickness of a separate conductor rod. That is, in each case, a phase of the winding is formed with a separate conductor rod cross-section. This winding design according to the invention becomes feasible, particularly due to the specific design of the dual-rotor radial flux motor, which prevents current displacement to the surface through its magnetic symmetry, which would otherwise occur in the conductor. This allows for a relatively thick conductor cross-section while still achieving a relatively uniform current distribution across the cross-section. For example, the thickness of the conductor rod can be in the range of several millimeters. In particular, they can be conductor rods with a square profile having side lengths of several millimeters, for example, in the range of 2 to 6 millimeters, particularly in the range of 3 to 5 millimeters. Similarly, other cross-sectional shapes are also possible.

[0038] According to one embodiment, each corresponding helical thread of the conductor rod is twisted such that the cross-section of the conductor rod is identical to its radial axis at every point on the conductor. This specifically relates to the twisting of conductor rods—particularly non-circular conductor rods—about the central axis of the stator or motor. Depending on the helical shape of the threads, the conductor rods can also be additionally bent. The inner and outer layers are arranged in an alternating manner, i.e., rotating, twisting, and bending relative to each other in opposite directions. In this way, from a mechanical point of view, the orientation of the conductor rods is ideally positioned to transmit power to the stator core at every point, such that each conductor rod bears the load uniformly along its length. Therefore, in the resulting rod structure, when subjected to tangential forces, the conductor rods advantageously absorb primarily tensile and compressive stresses. In this way, load peaks and deformation of the conductor rods are avoided. In particular, mechanical stresses are thus significantly reduced compared to a straight conductor design parallel to the axis.

[0039] According to one embodiment, the radially inner and outer conductor rods associated with the in-phase winding are connected together at the ends of the conductor rods in each case, particularly by radially arranged conductor rods and / or by integral bonding. In addition to conductor rings or loops, this forms a structure similar to a torsion-resistant rigid rod, allowing the winding to absorb high torque without inducing unacceptably large deformations and / or stress states when the axially accessible winding ends are fixed. Therefore, a self-supporting design of the winding can be achieved using only a winding material such as copper, without the need for additional support devices or elements.

[0040] According to another embodiment, the stator core includes a laminated stator core with stator slots extending helically corresponding to the winding threads. The inner stator slots, radially inner, extend according to a first rotational direction, while the outer stator slots, radially outer, extend in opposite directions relative to each other according to a second rotational direction. The windings, or self-supporting rod structures formed therefrom, are embedded in the laminated stator core. Similar to the conductor rods of the windings, the stator slots change their tangential positions according to their axial position, forming a helical shape. The direction of position change follows the conductor rods; that is, the centerlines of the radially outer and radially inner slots also describe the helix, with opposite rotational directions corresponding to the first or second rotational direction.

[0041] In other embodiments, other manufacturing types known to those skilled in the art are also feasible, which can be used to manufacture the stator core geometry according to the invention, in which the radial inner groove and radial outer groove extend helically in opposite directions. In particular, additive manufacturing types, such as sintering or similar methods, can also be used.

[0042] According to one embodiment, only one conductor rod is installed in each stator slot of the laminated stator core. As explained in the section on windings, the conductor rods of the inner and outer stator slots are helically interlaced with each other by a torsion about the central axis of the motor, thereby guiding the ends of the inner and outer conductors toward each other. The conductor rods are electrically connected together at their ends, particularly by radially arranged conductor rods and / or by integral bonding, such as by welding or brazing.

[0043] According to one embodiment, the inner and outer conductive connecting conductors together form a wavy winding strand. These winding strands can be interconnected using appropriate connection methods known to those skilled in the art to form a rotating magnetic field generating a winding with a desired or adjustable number of strands. The number of turns maintaining the voltage is determined directly by the quotient of the product of the number of grooves in the molecule and the number of strands and parallel branches in the molecule. In an advantageous manner, the number of parallel branches is chosen to be 1. In this case, the winding with the simplest possible interconnection is manufactured.

[0044] According to one embodiment, the stator laminations of the stacked stator core are all formed identically in each case, each having grooves provided for forming stator slots. The helical threads of the stator slots are formed by stacking the stator laminations in a manner that allows for mutual rotation. In this way, the stacked stator core can be manufactured very economically, because all parallel or stacked stator laminations can be produced using the same die. Thus, adjacent stator laminations are rotated slightly about a predetermined angle relative to each other around a central axis, causing the grooves to overlap, corresponding to the threads of the helix.

[0045] According to another embodiment, the stacked stator core includes an inner partial package with radially inner stator slots and an outer partial package with radially outer stator slots, wherein the stator laminations of the inner partial package are designed to have the same geometry in each case, and the stator laminations of the outer partial package are designed to have the same geometry in each case. Furthermore, the stator laminations of the inner partial package are stacked according to a first rotation direction of the conductor rod, and the stator laminations of the outer partial package are stacked according to a second rotation direction of the conductor rod, and they are twisted relative to each other about the central axis by a predetermined torsion angle.

[0046] In another embodiment, the torsion angle of the stator laminations about the central axis is the same as the sweep angle of the stator slots. This allows for the manufacture of stator slots with opposite helical lines at minimal manufacturing cost. Nevertheless, a very economical manufacturing method is still permitted because all parallel or stacked stator laminations in the internal partial encapsulation can use the same die, as can all parallel or stacked stator laminations in the external partial encapsulation. Thus, two adjacent stator laminations in the internal partial encapsulation are slightly rotated relative to each other in a first rotational direction by a predetermined torsion angle about the central axis, while two adjacent stator laminations in the external partial encapsulation are slightly rotated relative to each other in a second opposite rotational direction by a predetermined torsion angle about the central axis. In this way, the slots of the internally and externally partially encapsulated stator laminations are arranged in a manner that overlaps with each other, corresponding to opposite helical thread trajectories.

[0047] According to one embodiment, the stator laminations of the stacked stator core are formed identically in all cases, each having grooves for forming stator slots. The helical threads of the stator slots are formed by stacking the stator laminations in a manner that allows them to rotate relative to each other. In this way, the stacked stator core can be manufactured very economically because all parallel or stacked stator laminations can be produced using the same die. Thus, two adjacent stator laminations are rotated slightly about a predetermined angle relative to each other about their central axis, causing the grooves to overlap, corresponding to the threads of the helix.

[0048] According to another embodiment, the stator laminations are formed differently in each case, having grooves provided for forming stator slots. The helical threads of the stator slots are provided by grooves at different distances in each stator lamination. In this case, a individually matched stator lamination shape is produced at each position in the stack, and individual geometries can also be repeated in the stack. In this case, manufacturing can be achieved by beam cutting processes, especially laser beam cutting processes, which are more flexible in terms of shape compared to punching processes. Furthermore, flexible dies with variable geometries can be used, or, in the case of a very large quantity, multiple separate punching dies or stamping dies can be provided for each different shape of stator lamination.

[0049] According to an extended example, the grooves for the radially inner stator slots and the radially outer stator slots are each integrally formed in a common stator lamination, wherein the opposing helical threads of the radially inner stator slots and the radially outer stator slots are provided by the continuous displacement or shifting of the inner stator slots and the outer stator slots relative to each other between the stator laminations. In this case, each position of the stator lamination in the stack also produces a separately matched stator lamination shape, wherein individual geometries can also be repeated in the stack. In this case, flexible separation processes, such as laser beam cutting, can also be used for manufacturing purposes. The integral production of the inner and outer grooves thus advantageously reduces the number of parts.

[0050] According to one embodiment, the stator laminations have straight, specifically perforated, edges. The width of the grooves provided for the stator slots is greater than the width of the conductor rod by an amount predetermined by the pitch of the helical shape of the stator slot threads and the thickness of the stator laminations. The net width or continuous width of the stator slot decreases due to the offset between the grooves of the stator laminations, thus substantially corresponding to the width of the conductor rod. In practice, the continuous net width of the stator slot is set to be slightly larger than the width of the conductor rod to provide the clearance fit required for introducing the conductor rod. Therefore, the edge of the stator slot depicts a staircase shape, with the thickness of each lamination serving as steps, and the conductor rod is uniformly supported on the steps. In this way, it becomes possible to achieve uniform torque support over the entire thickness of the laminated stator core or over the entire length of the conductor rod housed within the laminated stator core.

[0051] According to one embodiment, the angle swept by the stator slot in each case is smaller than the angle swept by the conductor rod in each case. The angle swept in each case is related to the rotation about the central axis of the stator. The difference in the angle swept is caused by the fact that the conductor rod protrudes axially beyond the stator core and is therefore longer than the stator slot. Since the helix also continues in this manner, a larger angle swept is produced. The above-mentioned difference is set to ensure sufficient accessibility of the winding ends for connection, particularly welding, after the ends of the conductor rod enter the stator slot. Furthermore, this allows the winding to engage with the support device or its support element in a manner that is axially offset relative to the stator core.

[0052] The so-called magnetic pole coverage of a laminated stator core can be defined by the quotient of the sweep angle, which is the ratio of the angle swept by each stator slot to the angle swept by each conductor rod.

[0053] According to one embodiment, the ratio of the angle swept by each stator slot to the angle swept by each conductor rod is in the range of 0.6 to 0.8, particularly between 0.6 and 0.75, and preferably between 0.6 and 0.7. Within this range, the ratio (pole coverage) achieves an optimal balance between losses from current heating and torque utilization.

[0054] According to one embodiment, at least one axial end of the winding protrudes beyond the stator core. Furthermore, a support device is provided, axially offset relative to the stator core, designed to engage with the winding shape at at least one axial end for torque support.

[0055] According to an advantageous extension, the support device has a support element in which the support groove is configured to correspond to and engage with the helical arrangement of the conductor rods. In this way, the conductor rods can be shaped and fitted into the support element to support torque at the axial ends. Preferably, this engagement with all conductor rods ensures uniform or consistent torque support across the entire rod structure of the winding.

[0056] To transmit torque, the support element can be coupled to the mechanically fixed base of the dual-rotor radial flux motor. For this purpose, one possible embodiment provides a through hole for a force-fit fastening device such as a screw, but of course, a form-fit connection or an integrally bonded connection can also be used.

[0057] According to one embodiment, the support groove follows the helical thread of a torsion conductor rod in at least several sections. In particular, the support groove has a similar torsion thread to the conductor rod. For example, the support element is generally annular and has grooves on its inner and / or outer peripheries, the grooves being radially oriented and corresponding to the thread of the conductor rod.

[0058] According to one embodiment, the support device has a radially inner support element for engaging with the radially inner layer of the conductor rod, and a radially outer support element for engaging with the radially outer layer of the conductor rod. In this embodiment, the support elements may be annular, wherein the inner support element has grooves or teeth on its outer periphery corresponding to the threads of the inner layer of the conductor rod for form-fitting reception of the radially inner conductor rod, and the outer support element has grooves or teeth on its inner periphery corresponding to the threads of the outer layer of the conductor rod for form-fitting reception of the radially outer conductor rod. The grooves or teeth particularly follow their respective helical threads. Because they are arranged on the inner or outer periphery, the recessed grooves are easy to machine, which simplifies the manufacture of the support element.

[0059] According to another embodiment, the total helix angle generated circumferentially by the permanent magnets of the inner rotor is within the range of 20% to 40%, preferably 25% to 35%, and particularly preferably 28% to 32%, of the torsion angle of the internally partially encapsulated stator laminations, and / or the total helix angle generated circumferentially by the permanent magnets of the outer rotor is within the range of 20% to 40%, preferably 25% to 35%, and particularly preferably 28% to 32%, of the torsion angle of the externally partially encapsulated stator laminations. Since the magnetic field distortion does not perfectly follow the thread of the stator slots of the respective stator laminations, the total helix angle generated by the permanent magnets of the inner and outer rotors is smaller than the torsion angle of the stator laminations. In this way, a particularly advantageous design is provided that achieves optimized torque increase through the relationship between the torsion angle of the stator laminations and the total helix angle generated by the permanent magnets.

[0060] According to another embodiment, the permanent magnets of the inner rotor and the outer rotor have predetermined tangential widths, wherein the stator core has a radial yoke thickness, which is in the range of 5% to 25% of the tangential pole width, preferably in the range of 10% to 20%, and particularly preferably in the range of 12.5% ​​to 17.5%. The tangential pole width, especially the local tangential pole width, is preferably the common tangential width of all permanent magnets constituting the pole. Furthermore, the maximum tangential pole width on the motor cross-section is determined arithmetically by multiplying the motor radius by a full revolution (2π or 360°) and dividing by twice the number of pole pairs p. The radial yoke thickness of the stator core can be increased to carry a certain amount of tangential flux at the ends of the dual-rotor radial flux motor, and thus reduce magnetic reluctance. Therefore, the radial yoke thickness used in the stator can be slightly increased compared to the conventional yokeless design, but without significantly increasing the weight of the laminated stator core.

[0061] According to one embodiment, the stator core is still primarily designed for transmitting radial flux. Therefore, this remains a so-called "yokeless" stator core design, where, particularly at the axial center of the motor, there is no significant flux transmission in the peripheral or tangential directions.

[0062] According to one embodiment of a dual-rotor radial flux motor, a support element is fixed to a base, thus directing torque to a fixed portion of the motor. For this purpose, the support element can be individually fastened to the motor base, such as a housing. Alternatively or additionally, the internal and external support elements can be fastened together.

[0063] According to one embodiment of the stator, the support device comprises a thermally conductive material, particularly a metal, preferably an aluminum alloy. Specifically, both support elements may comprise this material. This not only allows for high mechanical strength but also allows for heat dissipation from the windings through the support device.

[0064] According to one embodiment of a corresponding dual-rotor radial flux motor having a support device including thermally conductive material, the base additionally has a heat sink designed to absorb heat dissipated from the stator through the support device, particularly from the windings. Therefore, the support device has high mechanical strength while also ensuring good thermal connection between the windings and the heat sink. For example, the motor housing can function as a heat sink. Alternatively or additionally, the support device, preferably internal and external support elements, can be in thermal contact with the motor's active cooling heat sink. In this way, current-induced heat losses in the windings or conductor rods can be effectively dissipated.

[0065] According to one embodiment of a dual-rotor radial flux motor, a predetermined number of pole pairs are arranged on both the first and second rotors. The sweep angle by each conductor bar is designed to form a conductor loop or circuit for each pole of the rotor. Therefore, the sweep angle to be provided can be calculated from the quotient of the full rotation (2π or 360°) divided by twice the number of pole pairs p.

[0066] Another aspect of this disclosure relates to a method of manufacturing a stator, comprising the steps of: providing a stator core having radially outer stator slots and radially inner stator slots, the radially outer stator slots describing a helix and having a first direction of rotation in each case, and the radially inner stator slots describing a helix having an opposite direction of rotation in each case; introducing individual conductor rods following the helixes through the inner stator slots and the outer stator slots; and connecting the conductor rods introduced into the inner stator slots and the outer stator slots at their ends to form conductor rings.

[0067] According to one embodiment of this manufacturing method, providing a stator core includes manufacturing a laminated stator core, wherein individual stator laminations having grooves for forming stator slots are stacked in a twisted manner relative to each other. In this way, a laminated stator core can be manufactured very economically because all parallel or stacked stator laminations can be produced using the same die or punching die. Thus, two adjacent stator laminations are rotated slightly about a predetermined angle relative to each other about a central axis, such that the grooves are arranged in an overlapping manner relative to each other, corresponding to the threads of a helix. Individual stator laminations with this geometry can be advantageously manufactured by punching or laser-cutting electrical steel into individual stacks.

[0068] According to an extended example of the method, the stacked stator core includes an inner partial package and an outer partial package, wherein all stator laminations of the inner partial package are designed to have the same geometry in each case, and all stator laminations of the outer partial package are designed to have the same geometry in each case, wherein the stator laminations of the inner partial package used to form the inner stator slots and the stator laminations of the outer partial package used to form the outer stator slots are stacked in a manner that is twisted in opposite directions relative to each other. In this case, all laminations of the corresponding inner and outer packages can be designed to have the same geometry, thus making the manufacturing process very economical. Therefore, all stator laminations of the inner partial packages arranged in parallel or stacked can use the same punching die, and all stator laminations of the outer partial packages arranged in parallel or stacked can use the same punching die. Two adjacent stator laminations of the inner partial package are slightly rotated about a predetermined angle relative to each other about a central axis in a first direction, and two adjacent stator laminations of the outer partial package are slightly rotated about a predetermined angle relative to each other about a central axis in a second direction. In this way, the grooves of the stator laminations of the inner and outer partial packages are arranged in a manner that overlaps in opposite directions relative to each other, corresponding to opposite spiral threads. In this way, the opposite spiral of the stator slot can be manufactured with very little manufacturing cost.

[0069] According to another embodiment of the method, the laminated stator core has a large number of stator laminations formed in different ways, wherein the grooves for the inner and outer stator slots are integrated in a common stator lamination in each case, wherein the pitch of the helix is ​​achieved by continuous displacement of the inner and outer stator slots relative to each other from stator lamination to stator lamination, particularly by means of flexible punching or laser beam separation processes. The inner and outer stator slots are integrated into a single stator lamination (laminated), and the helical threads of the stator slots are achieved in each individual lamination by means of continuous displacement of the grooves relative to each other during separation—for example, by flexible punching or laser beam separation processes. This has the advantage that fewer components also mean fewer manufacturing steps, and thus the manufactured stator laminations or the entire stator core have greater mechanical strength.

[0070] In another embodiment, the method further includes: providing a support device designed to engage with a conductor rod end in a form-fit manner at at least one axial end for torque support; and engaging the support device with the conductor rod end in a form-fit manner at at least one axial end at a position offset relative to the stator core axially.

[0071] Furthermore, according to one aspect, a stator manufactured in this manner can be used to perform a method of manufacturing a dual-rotor radial flux motor, the method further comprising the steps of: providing a mechanically fixable base and support device, the support device being designed to engage with a winding in a form-fit manner at at least one axial end for torque support; fastening the support device to the base; and providing dual rotors having an inner rotor and an outer rotor and a common central axis, wherein each of the inner and outer rotors has an annular body designed for transmitting flux, wherein a plurality of permanent magnets are fastened to the annular body in each case, each permanent magnet being assigned in cross-section to a predetermined corner segment of the annular body, wherein the permanent magnets are formed and disposed on the respective annular body such that the corner segment is circumferentially displaced in an axial progression to cause the permanent magnet to generate a magnetic field extending obliquely relative to the central axis, wherein the magnetic field of the inner rotor extends obliquely along a first direction toward a first rotational direction, and the magnetic field of the outer rotor extends obliquely along a second direction toward a second rotational direction.

[0072] The above embodiments and extensions can be combined with each other in any way, if such combination is useful. In particular, all features of the stator can be transferred to the stator manufacturing method, and all features of the stator manufacturing method can be transferred to the stator. Furthermore, all features of the stator can be transferred to the corresponding dual-rotor radial flux motor, and the axle having such a dual-rotor radial flux motor and / or the vehicle having such an axle.

[0073] Other possible embodiments, extensions, and implementations of the invention include combinations of features not explicitly mentioned therein, as described herein or which will be described below with reference to exemplary embodiments. In particular, those skilled in the art will also add individual aspects as improvements or supplements to the corresponding basic forms of the invention in this regard. Attached Figure Description

[0074] The present invention will now be explained in more detail with the aid of exemplary embodiments illustrated in the accompanying drawings. In the drawings:

[0075] Figure 1 An exploded view of a dual-rotor radial flux motor with a stator and two rotors is shown.

[0076] Figure 2 An exploded view of a dual-rotor system is shown.

[0077] Figure 3 A plan view of the two axial sections of the permanent magnet is shown;

[0078] Figure 4 A schematic cross-sectional view showing the inner rotor and outer rotor with permanent magnets;

[0079] Figure 5A plan view of a parallelogram-shaped permanent magnet is shown.

[0080] Figure 6 A schematic cross-sectional view of the inner and outer rotors, which have parallelogram-shaped permanent magnets, is shown.

[0081] Figure 7 A three-dimensional view of the winding is shown;

[0082] Figure 8 A three-dimensional view of the stator core is shown;

[0083] Figure 9 A cross-sectional view of a dual-rotor radial flux motor is shown.

[0084] Figure 10 A cross-sectional view of a dual-rotor radial flux motor according to another embodiment is shown;

[0085] Figure 11A -C shows a cross-sectional view of a dual-rotor radial flux motor at different axial positions with the indicated magnetic field distortion;

[0086] Figure 12 A schematic longitudinal sectional view of the stator is shown;

[0087] Figure 13 A schematic longitudinal sectional view of a dual-rotor radial flux motor is shown.

[0088] Figure 14 An exploded view of a dual-rotor radial flux motor according to one embodiment is shown;

[0089] Figure 15 An exploded view of a stator according to one embodiment is shown;

[0090] Figure 16 An exploded view of a dual-rotor radial flux motor according to another embodiment is shown;

[0091] Figure 17 It shows Figure 16 The diagram shows a three-dimensional view of the dual-rotor radial flux motor in its installed state.

[0092] Figure 18 A perspective longitudinal sectional view of a dual-rotor radial flux motor according to yet another embodiment is shown;

[0093] Figure 19 An exploded view of the stacked stator cores is shown.

[0094] Figure 20 A schematic longitudinal sectional view of the stator slot is shown;

[0095] Figure 21 A plan view of the winding is shown;

[0096] Figure 22 A three-dimensional view showing the finite element simulation of the winding under load;

[0097] Figure 23 A perspective view showing a finite element simulation of a comparative winding with a conductor rod having a straight design under load; and

[0098] Figure 24 A flowchart illustrating the method for manufacturing the stator is shown.

[0099] The accompanying figures are intended to provide a better understanding of embodiments of the invention. They illustrate embodiments and, together with the descriptive sections, serve to explain the principles and concepts of the invention. Other embodiments and many of the described advantages will become clear with reference to the figures. Elements in the figures are not necessarily illustrated to scale relative to each other.

[0100] In the figures, unless otherwise stated, similar and functionally identical elements, features and components, as well as elements, features and components that operate in the same manner, are given the same reference numerals. Detailed Implementation

[0101] Figure 1 An exploded view of a dual-rotor radial flux motor 10 having a stator 1 and dual rotors 100 is shown.

[0102] The stator 1 and the dual rotors 100 of the dual rotor radial flux motor 10 have a common central axis M. The stator 1 is concentrically housed between the inner rotor 12 and the outer rotor 13 of the dual rotors 100.

[0103] The stator 1 has a stator core 2 and an anti-torsional rigid winding 3 housed therein. In the radial interior of the stator 1, the conductor rods 6 of the anti-torsional rigid winding 3 extend helically in a first rotational direction. In the radial exterior of the stator 1, the conductor rods 6 of the anti-torsional rigid winding 3 extend helically in the opposite second rotational direction.

[0104] The dual rotor 100 has an inner rotor 12 and an outer rotor 13. Each of the inner rotor 12 and outer rotor 13 has an annular body 102, 103. The annular bodies 102, 103 are designed to transmit flux and have a common central axis M. In each case, a plurality of permanent magnets 29 are fastened to the annular bodies 102, 103. Each permanent magnet 29 is distributed within a predetermined corner segment 32, 33 of the annular bodies 102, 103 in a cross-section. The predetermined corner segments 32, 33 extend in an arcuate manner along the circumference of the annular bodies 102, 103.

[0105] Permanent magnets 29 are designed and mounted on corresponding annular bodies 102 and 103, such that predetermined corner segments 32 and 33 are circumferentially displaced during axial movement. Therefore, permanent magnets 29 generate magnetic fields 34 and 35 that extend obliquely relative to the central axis M. The magnetic field 34 of the inner rotor 12 extends obliquely along a first direction, which is oriented towards a first rotational direction of the torsional rigid winding 3. The magnetic field 35 of the outer rotor 13 extends obliquely along a second direction, which is oriented towards a second rotational direction of the torsional rigid winding 3.

[0106] Figure 1 The magnetic fields 34 and 35 of the permanent magnet 29 are illustrated by the diagonal dashed arrows. In each case, magnetic fields 34 and 35 extend in an oblique manner relative to each other. As shown, the magnetic field propagation lines of magnetic fields 34 and 35 extend in opposite oblique manner on the permanent magnet 29 of the inner rotor 12 and the outer rotor 13.

[0107] The construction and arrangement of the permanent magnet 29 used for the axial displacement of corner segments 32 and 33 are not limited to the design shown in this case, but can be modified in various ways.

[0108] Figure 2 An exploded view of the dual rotors is shown.

[0109] The dual rotor 100 has an inner rotor 12 and an outer rotor 13. The inner rotor 12 is concentrically housed within the outer rotor 13. A plurality of permanent magnets 29 are arranged on the inner surface of the annular body 103 of the outer rotor 13.

[0110] The permanent magnet 29 is allocated to predetermined corner segments 32 of the annular body 103 within its cross-section. For example... Figure 2 As shown, the corner segment 32 is displaced or moved along the axial process in the circumferential direction, and the adjacent axial segments 30 of the permanent magnet are arranged accordingly in the circumferential direction by axial displacement.

[0111] In this case, the permanent magnet 29 is, for example, divided into multiple axial segments 30. However, in a further embodiment, the permanent magnet 29 may have other configurations and arrangements to allow the corner segments 32, 33 to be displaced along the axial direction.

[0112] This geometric relationship is similarly arranged on the outer surface of the annular body 102 of the inner rotor 12. In other embodiments, as an alternative or supplement to the illustrated arrangement of permanent magnets on the surfaces of the inner and outer rotors 12, 13, the permanent magnets 29 may also be recessed into the annular bodies 102, 103. Furthermore, the annular bodies 102, 103 are made of solid material.

[0113] Figure 3 A plan view of the permanent magnet 29 is shown.

[0114] The permanent magnet 29 is set with an exemplary predetermined helix angle ε relative to the axial direction of the central axis M on the annular bodies 102, 103 (not shown).

[0115] The permanent magnet 29 shown in the figure is divided into multiple axial segments 30, for example. In each case, the axial segments 30 are assigned to corner segments 32, 33 (not shown) of the corresponding body, and the corner segments are displaced by a set angle θ relative to the adjacent axial segments 30 about the central axis M.

[0116] The total helix angle φ generated by the permanent magnet is determined from a geometric perspective based on a set angle θ, particularly a multiple of the set angle θ. In the case where each permanent magnet 29 has a predetermined number of axial segments 30 (n), the total helix angle φ is determined based on the set angle θ using the relationship φ = n * θ. Furthermore, in this case, the predetermined helix angle ε, as illustrated by example, is configured as a function of the length of the dual-rotor radial flux motor 10. In other embodiments, the predetermined helix angle may be defined in a manner different from that shown in the figure. In this respect, in... Figure 3 The example simply shows ε as the projection angle on the circumferential surface of permanent magnet 29.

[0117] like Figure 3 As shown, the axial segment 30 in the illustrated embodiment has a long side parallel to the central axis M. In this embodiment, this allows for optimal utilization of the surfaces of the annular bodies 102 and 103. According to another embodiment, the edges of the axial segment 30 can be arranged on the annular bodies 102 and 103 at a specific angle relative to the central axis; for example, the edges of the axial segment 30 can be oriented along a predetermined helix angle ε. Furthermore, in other embodiments, other orientations of the axial segment 30 can also be found on the surfaces of the annular bodies 102 and 103, and these other orientations produce the desired total helix angle for the arrangement.

[0118] Figure 4 A schematic cross-sectional view of the inner rotor and outer rotors 12, 13 having permanent magnets 29 is shown.

[0119] like Figure 3 As shown, the permanent magnets 29 are arranged one in front of the other on the annular bodies 102 and 103 in the axial direction. The figure also shows the total helix angle φ and the set angle θ generated around the central axis M (not shown) of the dual-rotor radial flux motor 10.

[0120] The circumferential displacement or shift of each of the two axial segments 30 relative to each other is described by a set angle θ. Due to the concentric arrangement of the annular bodies 102 and 103 and the only radial offset arrangement of the axial segments 30 on the respective annular bodies 102 and 103, the set angle θ of the permanent magnet 29 is equal in opposite directions on the inner rotor and the outer rotors 12 and 13. This arrangement of the axial segments 30 also plays a decisive role in the function of the dual rotors 100.

[0121] As already described, the total helix angle φ generated in the circumferential direction is determined based on the set angle θ of the axial segment 30 and the number of axial segments 30. Furthermore, in the case of a rectangular design of the axial segments 30 of the permanent magnet 29 having planar surfaces, gaps exist between the inner or outer circumferential surfaces of the annular bodies 102, 103 and the corresponding axial segments 30. For example, in the case where the axial segments 30 of the permanent magnet 29 are integrally bonded to the annular bodies 102, 103, such gaps can be filled with an integral adhesive medium. The integral bond can be established, for example, by means of a suitable adhesive. However, it should be noted that other mechanisms and methods for fastening are possible, particularly those that do not create gaps between the annular bodies 102, 103 and the corresponding axial segments 30. Alternatively or additionally, for example, local grooves on the rotor can also be used to compensate for gaps. Furthermore, in other embodiments, the inner and outer permanent magnets may have the same size, or, as shown here, may have different sizes, preferably to cover the same corner segments in the radial orientation.

[0122] Figure 5 A plan view of the parallelogram permanent magnet 29 is shown.

[0123] The shape of the axial section 30 or the permanent magnet 29 may differ from that of the other two sections. Figure 3 A rectangular shape, such as Figure 5 As shown, the permanent magnet 29 has a parallelogram shape, wherein the hypotenuse 31 of the permanent magnet 29 is inclined at a predetermined helix angle ε relative to the axial direction of the central axis M. In this respect, the same total helix angle φ is generated circumferentially around the central axis M of the permanent magnet 29. When using the parallelogram permanent magnet 29, the surfaces of the annular bodies 102, 103 (not shown) can be optimally utilized, the permanent magnet 29 does not protrude, and no empty space is left on the surface.

[0124] Figure 6 A schematic cross-sectional view of the inner rotor and outer rotors 12, 13 with parallelogram permanent magnets 29 is shown.

[0125] With relative to Figure 4Using a similar method as explained, the total helix angle φ generated in the circumferential direction around the central axis M, as indicated, can be observed. The generated total helix angle φ describes the sweep angle in the circumferential direction, which is generated by the hypotenuse 31 (not shown) of the corresponding permanent magnet 29. Related Figure 4 The problem of gaps occurring at the inner rotor 12 and outer rotor 13, as described above, can be solved in a similar manner with the illustrated parallelogram permanent magnet 29. The permanent magnets 29 are positioned relative to each other on the annular bodies 102 and 103, according to the resulting total helix angle φ. For the illustrated permanent magnets 29 on the inner and outer rotors 12 and 13, since their rotation directions are opposite, the total helix angle φ relative to the circumference is numerically opposite and equal.

[0126] In the illustrated embodiment, the inner permanent magnet and the outer permanent magnet 29 may be of different sizes so as to cover the same corner segment in the radial direction.

[0127] However, in other embodiments, the inner and outer permanent magnets may also be the same size, for example, to reduce costs within the scope of an integrated strategy.

[0128] Figure 7 A three-dimensional view of winding 3 is shown.

[0129] The winding 3 is composed of the conductor rods 6, which extend helically along the central axis M. For this purpose, the conductor rods 6 are not only arranged in a corresponding staggered manner, but also twisted to each other according to the thread of the helix.

[0130] The sweep angle β of conductor rod 6 determines the angle between the start and end points of conductor rod 6 relative to the central axis M. Since the pitch of the helix of conductor rod 6 is equal to the pitch of the helixes of stator slots 19 and 20, but conductor rod 6 is longer than the stator slots, a ratio of sweep angles α and β can be formed to characterize the geometry; this ratio is also called pole coverage. To provide an optimal balance between magnetic loss and torque utilization in the dual-rotor radial flux motor, this ratio (pole coverage) is preferably in the range of 0.6 to 0.75.

[0131] In this case, the opposite rotation and torsion of the radial inner and radial outer layers 14, 15 of the conductor rod 6 can also be observed. The torsion is configured such that the cross-section associated with the radial line passing through the center of the conductor rod is always the same at every point on the conductor rod, which is also defined as a 2.5D geometry. Therefore, the ends of the conductor rods of the inner and outer layers 14, 15 are arranged in the same orientation one after the other. Thus, the conductor rods 6 of the radial inner and outer layers 14, 15 can be electrically connected in a simple manner, for example, by welding to the radially extending conductor rod 17 of the conductor rod 6.

[0132] It is important to note that the windings described here are not manufactured separately, but are always manufactured in conjunction with the stator core 2. Figure 23 Let's discuss this in more detail.

[0133] The winding 3 has a radial inner layer 15 of a helically arranged conductor rod 6 in the radial interior of the stator 1 (not shown), and a radial outer layer 14 of a conductor rod 6 with an opposite helical arrangement in the radial exterior of the stator 1.

[0134] Figure 8 A three-dimensional view of stator core 2 is shown.

[0135] The stator core 2 includes a laminated stator core 18 having winding threads corresponding to helically extending stator slots 19, 20. The inner stator slots 20 of the stator 1 (not shown) extend radially inward according to a first rotation direction, and the outer stator slots 19 of the stator 1 extend in opposite directions relative to each other according to a second rotation direction.

[0136] The laminated stator core 18 includes an inner partial package 23 with radially inner stator slots 20 and an outer partial package 24 with radially outer stator slots 19. Each stator lamination 22 of the inner partial package 23 is manufactured with the same geometry, and each stator lamination 21 of the outer partial package 24 is manufactured with the same geometry. The stator laminations 22 of the inner partial package 23 are stacked according to a first rotational direction of the conductor rod 6 (not shown), and the stator laminations 21 of the outer partial package 24 are stacked according to a second rotational direction of the conductor rod 6, thereby being twisted relative to each other about the central axis M by a predetermined torsion angle γ. The indicated torsion angle γ describes the circumferential angle between the axial ends of the laminated stator core 18 relative to the central axis M, which is generated by the rotation of the individual stator laminations 21, 22 relative to each other.

[0137] In a particular embodiment, the sweep angle α of the stator slot is the same as the torsion angle γ.

[0138] Because the magnetic field distortion does not perfectly follow the thread of the stator slots, the total helix angle φ generated circumferentially must be less than the torsion angle γ. Therefore, the total helix angle φ (not shown) generated circumferentially in the permanent magnet 29 of the inner rotor 12 is within the range of 20% to 40% of the torsion angle γ of the stator lamination 22 of the inner partial encapsulation 23, and / or the total helix angle φ generated circumferentially in the permanent magnet 29 of the outer rotor 13 is within the range of 20% to 40% of the torsion angle γ of the stator lamination 21 of the outer partial encapsulation 24. This adaptation of the total helix angle φ generated circumferentially to the torsion angle γ maximizes torque.

[0139] Figure 9 A cross-sectional view of a dual-rotor radial flux motor 10 is shown.

[0140] The arcuate portion of the illustrated dual-rotor radial flux motor 10 shows conductor rods 6, permanent magnets 29, stator 1, inner rotor 12, outer rotor 13, and annular bodies 102 and 103. Furthermore, the flux (quantity) is also indicated in the tangential direction of the inner and outer rotors 12 and 13, and in the radial direction of the stator 1. In the illustrated embodiment, the stator 1 is "yokeless." Therefore, although the stator yoke 38 extends between the conductor rods 6, its function is merely to mechanically hold the stacked stator cores 18 (not shown) of the stator 1 together. Figure 9 As shown, the stator yoke 38 is located in the functionally relevant flux. However, in the illustrated embodiment of the dual-rotor radial flux motor 10, the tangential flux transmission at the axial end of the dual-rotor radial flux motor 10 is reduced. This negatively impacts the efficiency of the dual-rotor radial flux motor 10, resulting in an undesirable torque reduction.

[0141] Figure 10 A cross-sectional view of a dual-rotor radial flux motor 10 according to another embodiment is shown.

[0142] and Figure 9 Compared to the previous embodiment, Figure 10 The embodiment of the dual-rotor radial flux motor 10 shown has a relatively thicker stator yoke 38 (not drawn to scale). The stator yoke 38 is described by the radial yoke thickness 36 shown.

[0143] The permanent magnets 29 of the inner rotor 12 and the outer rotor 13 each have a predetermined tangential width 37. In a particularly advantageous embodiment, the stator core 2 has a radial yoke thickness 36, which is in the range of 10% to 20% of the tangential width 37 of the permanent magnets 29. Therefore, tangential flux transmission can be supported at the axial end of the dual-rotor radial flux motor 10.

[0144] In one embodiment, the cross-section of the permanent magnet 29 having a parallelogram shape is decisive for the relationship between the tangential width 37 and the radial yoke thickness 36 of the permanent magnet 29.

[0145] Figure 11A -C shows a cross-sectional view of a dual-rotor radial flux motor 10 with the indicated magnetic field distortion.

[0146] Three sectional views (left side) Figure 11A The middle Figure 11B The right side Figure 11C Each describes an axial position within the dual-rotor radial flux motor 10. The left sectional view shows the front end of the dual-rotor radial flux motor 10, the middle sectional view shows the axial center of the dual-rotor radial flux motor 10, and the right sectional view shows the rear end of the dual-rotor radial flux motor 10.

[0147] The dual-rotor radial flux motor 10 illustrated in this case includes an integral permanent magnet 29 arranged axially. As can be seen from Figure 11, only the mid-section view of the dual-rotor radial flux motor 10 shows a uniform magnetic field, where the magnetic field lines in the stator 1 extend only radially. In the left and right sectional views of the dual-rotor radial flux motor 10, as shown, magnetic field distortion occurs. In the left and right sectional views, the respective magnetic field lines are inclined accordingly, particularly within their respective stators.

[0148] Furthermore, it is clear from the three sectional views that the conductor rod 6 is displaced through the axial position (front end, axial center, rear end) of the dual-rotor radial flux motor 10. Only in the middle view are conductor rods 6 with the same number of strands (U, V, W) and the same current direction (+, -) positioned one on top of the other. Therefore, the magnetic field has its maximum amplitude only at the axial center of the dual-rotor radial flux motor 10. Due to the basic geometric relationship between the conductor rod 6 and the permanent magnet 29, the amplitude of the magnetic field decreases towards the two axial ends of the dual-rotor radial flux motor 10 (the sectional views on the left and right sides). The resulting magnetic field distortion leads to a decrease in torque because the permanent magnet in the rotor is no longer in the optimal position for torque generation in each case. This situation can be seen from the references located on the corresponding annular bodies 102, 103. Figures 1 to 6 The permanent magnet 29 is configured and constructed in a circumferential direction along the axial direction to cancel each other out, so that the permanent magnet 29 generates magnetic fields 34, 35 that extend at an angle relative to the central axis M, and the magnetic fields are optimally arranged within the range of magnetic field distortion.

[0149] Figure 12 A schematic longitudinal sectional view of stator 1 is shown.

[0150] This is for a dual-rotor radial flux motor 10 (see in this regard) Figure 13 The diagram shows, in particular, a stator 1 for a hub motor. The stator has a stator core (or stator iron core) 2, windings 3, and a support device 5. The stator core 2, windings 3, and support device 5 are designed to be rotationally symmetric about the central axis M shown.

[0151] The winding 3 is self-supporting for torque support of the stator 1 and protrudes beyond the stator core 2 at at least one axial end 4. The support device 5 is arranged axially offset relative to the stator core 2 and is connected to the winding 3 in a form-fit manner at at least one axial end 4 for torque support. In this way, during operation of the dual-rotor radial flux motor 10, the torque present on the stator core 2 can be supported by means of the self-supporting winding 3 on the support device 4.

[0152] The windings comprise a conductor material with low resistance, preferably copper. The stator core 2 is preferably constructed of a soft magnetic material for magnetic flux transmission. The support structure preferably comprises a thermally conductive material, such as an aluminum alloy. The windings 3 are electrically isolated.

[0153] Figure 13 A schematic longitudinal sectional view of a dual-rotor radial flux motor 10 is shown.

[0154] This is also a purely illustrative diagram. Therefore, besides Figure 12 In addition to the stator 1 shown, the dual-rotor radial flux motor 10 also has a mechanically fixed base 11, a first rotor 12, and a second rotor 13. The stator core 2, windings 3, support device 5, base 11, first rotor 12, and second rotor 13 are similarly designed to be rotationally symmetric about the central axis M shown.

[0155] The winding 3 is self-supporting for torque support of the stator 1 and protrudes beyond the stator core 2 at at least one axial end 4, and is supported on the base 11 by a support device 5. The support device 5 is arranged axially offset relative to the stator core 2 and is connected to the winding 3 in a form-fit manner at at least one axial end 4. Again, the support device 5 is fastened to the base such that torque can be supported on the base 11 through the support device 5.

[0156] The first rotor 12 is arranged radially inside the stator core 2, and the second rotor 13 is arranged radially outside the stator core 2. The base 11 can be designed as, for example, the housing of an electric motor, in which case it includes an L-shaped structure, illustrated in purely illustrative terms, having two limbs 7, 8. The illustration should not be construed as exhaustive; rather, the base may have other components and / or structural parts. The first limb 7 extends generally radially, and the second limb 7 extends generally axially, with the greatest distance relative to the central axis M.

[0157] Purely illustrative, the support device 5 is shown as a single component extending radially, but it may also be configured as multiple components and / or have another geometry for form-fitting connection to the winding 3. The overlap of the winding 3 with the base 11 shown is purely for illustrative purposes and does not represent a direct connection. The winding 3 is preferably connected to the base 11 via the support element 5 for torque support.

[0158] Figure 14 An exploded view of a dual-rotor radial flux motor 10 according to one embodiment is shown.

[0159] In addition to the components of the stator 1, the dual-rotor radial flux motor 10 also includes a first rotor 12, a second rotor 13, and a base 11. The first rotor 12 is radially arranged inside the stator core 2, and the second rotor 13 is radially arranged outside the stator core 2. The rotors 12 and 13 are preferably made of a soft magnetic solid material, and permanent magnets, i.e., surface magnets, are mounted on their respective surfaces facing the stator core as magnetic poles. The permanent magnets 29 are as follows... Figure 1 and Figure 2 The settings are as shown.

[0160] In this case, for clarity, the base 11 is only schematically illustrated. As already described... Figure 13 As described above, the base 11 is fastened to the support device 5 in the installed state. The base 11 is mechanically fixed relative to a reference system such as a bracket for a vehicle axle.

[0161] Figure 15 An exploded view of stator 1 according to one embodiment is shown.

[0162] The stator 1 has a winding 3, a stator core 2, and a support device 5, wherein, in this case, an advantageous exemplary design of these components is illustrated more precisely in a perspective view.

[0163] The winding 3 consists of an inner layer and an outer layer with multiple conductor rods 6 connected together in a rod structure. The conductor rods 6 in the inner and outer layers are arranged opposite each other in a spiral manner, and are integrally bonded to the radial conductor 17 connecting the inner and outer layers at the ends of the conductor rods.

[0164] In each case, the thickness of the inner and outer layers corresponds to the thickness of the conductor rod 6. That is, the winding 3 is formed by means of a single conductor layer in the manner of the corresponding conductor rod 6, the single conductor layer forming a conductor ring with a relatively large cross-section.

[0165] Because of the rod structure formed by the conductor rod, the winding is torsional rigid and thus self-supporting for torque support.

[0166] Therefore, conductor rod 6 forms wavy winding strands and can be interconnected by means of corresponding interconnection methods—which are known to those skilled in the art and therefore will not be described further—such as, for example, delta connection, star connection or similar methods, to form a rotating field generating winding with an arbitrary number of strands.

[0167] For example, in the illustrated embodiment, the stator core 2 and the support device 5 each consist of two components. For assembling the stator 1, the winding 3, stator core 2, and support device 5 are arranged in a nested manner. After assembly, these components are coaxially oriented relative to each other on a common central axis M. The support device 5—here, divided into two parts—is axially offset relative to the other components and constitutes the innermost and outermost components of the stator 1. These are the inner and outer rings, each designed with grooves for engaging with the shape of the conductor rod.

[0168] Stator core 2—here, taking a two-part example—is formed by two stacked stator cores 18, which rotate relative to each other in a helical manner, as will be discussed in reference to... Figure 19 Further detailed discussion.

[0169] In other embodiments, the stator core 2 and the support device 5 may each be formed by one or more components.

[0170] Figure 16 An exploded view of a dual-rotor radial flux motor 10 according to another embodiment is shown.

[0171] In this case, the dual-rotor radial flux motor 10 has a relative to Figure 15 and Figure 4 The components described are basically the same. The stator core 2, winding 3, first rotor 12 and second rotor 13 are shown in their assembled state on the left side of the figure.

[0172] The support device 5 shown on the right is similarly formed in two parts, but differs in the arrangement of the corresponding annular inner support element 27 and outer support element 28. In this case, support elements 27 and 28 are equipped with support grooves 26. These are provided on the inner periphery of the outer support element 28 and the outer periphery of the inner support element 27 for engagement with the conductor rod 6 of the winding 3.

[0173] For this purpose, the support grooves 26 are designed to be axially inclined in relation to the helical thread or pitch of the conductor rod, so that they can engage with the conductor rod 6 of the winding 3.

[0174] Support elements 27 and 28 are preferably made of conductive metal, particularly preferably of aluminum alloy. The two-part design of support elements 27 and 28 makes the support groove 26 easily accessible during manufacturing for mechanical or machining operations.

[0175] The inner support element 27 and the outer support element 28 each have a plurality of holes 9 along their circumference for fastening to the base 11. In this case, the holes 9 are arranged, for example, along a circular pattern of holes evenly distributed around the periphery. The individual holes 9 are located slightly outside the body of the support element, so that the support elements 27 and 28 in each case form a star shape on their periphery away from the winding. Of course, other arrangements of the holes 9 are also possible, such as other types of fastening devices for connection to the base 11.

[0176] Figure 17 Show Figure 16 The diagram shows a perspective view of the dual-rotor radial flux motor 10 in its installed state.

[0177] The support device 5 is fastened to the motor housing (not shown) through the hole 9, for example, serving as a base 11, thus transmitting torque to the mechanically fixed portion of the dual-rotor radial flux motor 10. In this way, the torque generated by the dual-rotor radial flux motor 10 is effectively supported. The fastening of the support device 5 is achieved by a corresponding fastening device (not shown) such as a screw.

[0178] The conductor rods 6 of winding 3 extend axially on both sides to the outside of stator core 2 and the first and second rotors 12 and 13. The radially inner and radially outer spirally arranged conductor rods 6 are connected together to the outside of stator core 2 in each case.

[0179] In this configuration, support elements 27 and 28 are shown engaging with the conductor rods 6 of the winding 3. It can be observed that each support slot 26 contains a conductor rod 6, such that all conductor rods are coupled to the support device in a form-fit manner. Therefore, the torque supported by the winding 3 can be supported by the support device 5 on the base 11, which is secured to the hole 9.

[0180] Figure 18 A perspective longitudinal sectional view of a dual-rotor radial flux motor 10 according to another embodiment is shown.

[0181] This embodiment and Figure 14 The assembly of the dual-rotor radial flux motor 10 shown is roughly the same, and its components will be discussed in further detail below.

[0182] The stator core 2 has an internal partial package 23 and an external partial package 24. The partial packages 23 and 24 extend annularly between the first rotor and the second rotor 12 and 13. The cross-sectional view also allows the inner and outer layers 14 and 15 of the conductor rods 6 extending within the partial packages 23 and 24 to be seen.

[0183] The illustrated dual-rotor radial flux motor 10 is a so-called "yokeless" design, where the yoke is not located between two teeth of functionally related flux. Therefore, although the stator yoke 38 extends between the conductor rods 6, its function is merely to mechanically hold the laminated stator cores 18 together. The thickness of the radial yoke can be correspondingly configured to be thin, in the illustrated embodiment, for example, by about 10% of the total radial stator thickness. Furthermore, due to the relatively small yoke thickness, undesirable leakage flux in the yoke is reduced. In other embodiments, for this purpose, the radial yoke thickness can be less than 30% of the total radial stator thickness, preferably less than 20%, and particularly preferably less than 10%.

[0184] The support device 5 also has an internal support element 27 and an external support element 28. In this case, it can be clearly observed that the support elements 27 and 28 are arranged axially offset relative to the stator 5 and the rotors 12 and 13. Furthermore, at least a plurality of portions of the support elements 27 and 28 can be seen to engage with the shape-fitting conductor rods 6 of the inner and outer layers 14 and 15.

[0185] In this case, it can also be clearly observed that the conductor rods 6 of the inner and outer layers 14, 15 are connected at the conductor rod ends 16 by radially arranged conductor rod members 17. This connection is preferably an integral adhesive connection, for example by means of laser beam welding.

[0186] Furthermore, the surface magnets of rotors 12 and 13 can be seen in cross-section. The first rotor 12 has multiple permanent magnets on its outer peripheral surface. The second rotor 13 has multiple permanent magnets on its inner peripheral surface.

[0187] A particularly advantageous embodiment is provided if the rotor is made of a soft magnetic solid material and fabricated with surface-mounted permanent magnets. In this design, the rotor can be manufactured very cost-effectively, and high efficiency can be achieved.

[0188] Figure 19 An exploded view of the stacked stator core 18 of stator core 2 is shown.

[0189] As already mentioned, the stacked stator core 18 of the stator core 2 has an inner partial package 23 and an outer partial package 24. This simplifies the manufacture of the stator slots 19, which rotate relative to each other in opposite directions, and have identical inner stator laminations 21 and outer stator laminations 22, which are stacked in a manner that rotates relative to each other and have grooves in the same positions.

[0190] In other embodiments, the stator laminations can also be integrally formed, allowing for the provision of various stator laminations with different shapes and different grooves, stacked in the order necessary to form the stator slots. In yet another embodiment, a completely integrally formed stator core 2 can also be provided, which can be manufactured, for example, by additive manufacturing.

[0191] In the two-part design illustrated, the inner diameter of the outer local package 24 is almost equal to the outer diameter of the inner local package 23. This allows the inner local package 23 to be coaxially positioned within the outer local package 24.

[0192] Local packages 23 and 24 are constructed from individual annular stator laminations 21 and 22, stacked one after the other. The stator laminations 21 of the outer local package 24 are formed with grooves positioned on the outer periphery to form an outer stator slot 19. The stator laminations 22 of the inner local package 23 are formed with grooves positioned on the inner periphery to form an inner stator slot 20. For example, such stator laminations can be manufactured by punching, which is advantageous due to edge quality and very low manufacturing cost.

[0193] The inner stator slot 19 and the outer stator slot 20 describe helices that extend in opposite directions relative to each other at the same pitch, characterized by an indicative sweep angle α of the stator slot. The sweep angle α of the stator slot can be defined as the angle relative to the central axis M between the positions of the same stator slot on one axial side of the stator core 2 and the positions on the other axial side of the stator core 2.

[0194] In this case, stator slots 19 and 20 are designed, for example, as T-slots with rectangular grooves having tapered openings. They are specifically configured to accommodate conductor rods with rectangular cross-sections in a form-fit manner. Of course, the geometry of the grooves or stator slots can be adapted to the geometry of the conductor. Other cross-sectional shapes are also feasible for this purpose.

[0195] Figure 20 A schematic longitudinal sectional view of stator slots 19 and 20 is shown.

[0196] The available or continuous net width 'a' of the stator slots 19 and 20 located inside the laminated stator core 18 is approximately equal to the width of the conductor rod 6 accommodated inside the stator core 2.

[0197] Stator laminations 21 and 22 have straight edges, particularly perforated edges. Due to the offset of the laminations relative to each other, the groove width b provided for stator slots 19 and 20 is an amount larger than the width d of conductor rod 6, which is predetermined by the pitch δ of the helical shape of the thread and the thickness t of the lamination.

[0198] exist Figure 20In the figure, the conductor rods 6 in the stator slots 19 and 20 are schematically marked with dashed lines. In order to provide clearance fit, the continuous net width a of the stator slots 19 and 20 is slightly larger than the width d of the conductor rods 6. Consequently, the width a of the grooves in the stator plates 21 and 22 is much larger than the net width b.

[0199] The thickness t of the sheet and the setting angle δ of the thread pitch of the groove represent significant influencing factors on the difference between the width b of the groove and the net width a of the available channel within the groove, in the case of, for example, the edge of a flat sheet with a punch. This difference arises because, on the one hand, the pitch angle needs to be compensated for, and on the other hand, the stair-like stepped structure of the stacked core needs to be compensated for.

[0200] In this case, the minimum dimension of the groove width 'a' in the limiting case of an infinitely thin sheet or plate—that is, considering only the pitch angle δ of the conductor rod—will be:

[0201] b = 1 / cos(δ)*d.

[0202] On the one hand, to compensate for the actual thickness of the plate, and on the other hand, to provide a clearance fit that allows the conductor rod to be inserted, the width b of the groove is actually set to be even larger.

[0203] Figure 20 The width b of the groove shown is sized in such a way that the net width a of the stator slots 19, 20—which is reduced by the offset between the grooves of the stator laminations—forms a predetermined clearance fit with the width d of the conductor rod 6 to be introduced into the stator slot, but this contact is tight enough, however, for power transmission or torque support uniformly distributed between the laminated stator core and windings. This sizing is possible, especially because, on the one hand, each stator lamination is formed identically with high edge quality and rotates with the same offset, and on the other hand, only a single conductor rod 6 is placed within each stator slot 19, 20, and the dimensions of the conductor rod are constant.

[0204] Specifically, in the illustrated embodiment, the conductor rod 6 is a rectangular rod with a side length or width of several millimeters, for example, in the range of 2mm to 6mm, particularly in the range of 3mm to 5mm. Preferably, this can be a rectangular profile of 5mm x 3mm.

[0205] Figure 21 The plan view of winding 3 is shown.

[0206] In this view, the precise radial orientation of the conductor rod at each point of its helical thread is clearly visible, and in the illustrated perspective view, the conductor rod is aligned in the region of the central axis M. In each case, the conductor rod end 16 forms the connection point between the radial inner layer and the radial outer layers 14, 15.

[0207] In the illustrated embodiment, the winding has, for example, a total of twelve connection contacts 31. In the case of a three-strand interconnection, three-phase operation is preferably provided. However, the winding can be adapted to other interconnection methods in a manner known to those skilled in the art to form a rotating magnetic field generating winding with any number of strands.

[0208] Figure 22 A three-dimensional view of the finite element simulation of winding 3 under load is shown.

[0209] In the case of a slight simplification for simulation purposes, this is essentially... Figure 7 The winding geometry is shown. The scale shown relates to the stress within the winding, which, for example, can be a scale from 0 MPa to 30 MPa in the case of a rectangular profile with a conductor rod 6 of 5 mm x 3 mm.

[0210] In this example, the end of the conductor rod is defined by a sweep angle β > 0, i.e., a helical arrangement and formation or a corresponding torsional formation. At the axial end where the support device engages, the maximum torque of the correspondingly sized dual-rotor radial flux motor 10 is plotted, as indicated by the thick arrow, where, for example, in the case of a rectangular profile with a conductor rod 6 of 5 mm x 3 mm, this can be approximately 5000 Nm.

[0211] Clearly, due to the geometry of the helix, the stress within the winding is distributed very evenly. Despite the apparent exaggeration of the setting, deformation is almost invisible. Therefore, this design significantly reduces stress peaks and consequently, deformation.

[0212] Due to this rod-like construction, when the axially accessible winding ends are fixed, winding 3 can absorb high torque in a self-supporting manner without generating unacceptably large deformations and / or stress states. This can be particularly attributed to the fact that, in a rod structure, when subjected to tangential forces, conductor rod 6 primarily absorbs tensile and compressive stresses.

[0213] Therefore, mechanical stress can be significantly reduced compared to designs with straight conductors having parallel axes.

[0214] Figure 23 A perspective view of a comparative model showing a straight design and axial progression of a conductor rod 6 under load is shown.

[0215] and Figure 22 In contrast, due to the straight design and axial progression of the conductor rod, it can be seen that... Figure 22 The stress threads concentrated on one side as shown on the left, and due to the Figure 23 The strong deformation of the conductor rod caused by localized high stress and large deflection on one side, as shown on the right. Here, a setting is established... Figure 22 The same stress scale and the same deformation amplification are used, which shows the effect of different structural configurations on torsional stiffness.

[0216] Figure 24 A flowchart is shown for the method of manufacturing stator 1.

[0217] The method includes a first step S1 of providing a stator core 2 having radially outer stator slots 19 and radially inner stator slots 20, each of the radially outer stator slots 19 describing a helix and each of the radially inner stator slots 20 describing a helix with opposite directions. A second step S2 involves introducing a single conductor rod 6 through the inner stator slots 19 and outer stator slots 20 following the helixes. Specifically, the conductor rod is introduced axially. Furthermore, a step S3 is provided to connect the conductor rod 6 introduced into the inner and outer stator slots at its end 16 to form a conductor ring.

[0218] Although the invention has been fully described above with reference to preferred exemplary embodiments, the invention is not limited thereto and can be modified in various ways.

[0219] List of reference numerals

[0220] 1 stator

[0221] 2 stator core

[0222] 3 windings

[0223] 4 Axial Ends

[0224] 5. Support device

[0225] 6 Conductor rods

[0226] 7 First limb

[0227] 8 Second limb

[0228] 9 holes

[0229] 10 Dual-rotor radial flux motor

[0230] 11. Base

[0231] 12 First Rotor / Inner Rotor

[0232] 13 Second Rotor / Outer Rotor

[0233] 14 Radial outer layer

[0234] 15 Radial Inner Layer

[0235] 16. Conductor rod end

[0236] 17 Conductor rods

[0237] 18-layer stator core

[0238] 19, 20 stator slots

[0239] 21, 22 stator laminations

[0240] 23 Internal local encapsulation

[0241] 24 External Local Packaging

[0242] 25 Supporting elements

[0243] 26 Support groove

[0244] 27 Internal support elements

[0245] 28 External support elements

[0246] 29 permanent magnet

[0247] 30 Axial section

[0248] 31 Hypotenuse; 32, 33 Predetermined angle segment; 34, 35 Magnetic field.

[0249] 36 yoke thickness

[0250] 37 Tangential width

[0251] 38 stator yoke

[0252] 100 Dual Rotor 102, 103 Annular Body α Stator Slot Sweep Angle β Conductor Rod Sweep Angle γ Twist Angle δ Pitch ε Predetermined Helix Angle θ Set Angle φ Total Helix Angle a Net Width b Groove Width d Conductor Rod Width

[0253] M central axis

[0254] Thickness of T-sheet

Claims

1. A dual-rotor radial flux motor (10), comprising: A stator (1), the stator (1) having a stator core (2) and an anti-torsion rigid winding (3) housed in the stator core (2), wherein, in the radial interior of the stator (1), the conductor rod (6) of the anti-torsion rigid winding (3) extends helically in a first rotational direction, and in the radial exterior of the stator (1), the conductor rod (6) of the anti-torsion rigid winding (3) extends helically in the opposite second rotational direction; and A dual rotor (100) having an inner rotor (12) and an outer rotor (13) and a common central axis (M), wherein each of the inner rotor (12) and the outer rotor (13) has an annular body (102, 103) designed for transmitting magnetic flux. In this configuration, multiple permanent magnets (29) are respectively fastened to the annular body (102, 103), and each of the permanent magnets (29) is assigned to a predetermined corner segment (32, 33) of the annular body (102, 103) in cross-section. The permanent magnet (29) is formed and disposed on the corresponding annular body (102, 103) such that the predetermined corner segments (32, 33) are circumferentially displaced in the axial process, so that the permanent magnet (29) generates a magnetic field (34, 35) that extends obliquely relative to the central axis (M), wherein the magnetic field (34) of the inner rotor (12) extends obliquely along a first direction toward the first rotation direction, and the magnetic field (35) of the outer rotor (13) extends obliquely along a second direction toward the second rotation direction.

2. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The annular bodies (102, 103) are made of solid material.

3. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The permanent magnet (29) is positioned at a predetermined helical angle ε relative to the axial direction of the central axis (M) on the annular body (102, 103).

4. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, Each of the permanent magnets (29) is divided into multiple axial segments (30), wherein each of the axial segments (30) is assigned a predetermined angle segment (32, 33), the predetermined angle segment being shifted by a set angle θ relative to the adjacent axial segment (30) about the central axis (M), wherein the total helical angle φ generated by the permanent magnet (29) along the circumference is determined according to the set angle (θ).

5. The dual-rotor radial flux motor (10) as described in claim 4, characterized in that, In the case where each of the permanent magnets (29) has a predetermined number of axial segments (30), the total helix angle φ is determined by means of the relation φ = n × θ, based on the set angle θ.

6. The dual-rotor radial flux motor (10) as described in claim 4 or 5, characterized in that, Each of the permanent magnets (29) is divided into two axial segments (30).

7. The dual-rotor radial flux motor (10) as described in claim 3, characterized in that, The permanent magnet (29) is oriented with its edge along the predetermined helical angle ε.

8. The dual-rotor radial flux motor (10) as described in claim 7, characterized in that, The permanent magnet (29) has an oblique parallelogram shape.

9. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The anti-torsion rigid winding (3) has a radial inner layer (15) of the conductor rod (6) arranged in a spiral arrangement in the radial interior of the stator (1), and a radial outer layer (14) of the conductor rod (6) arranged in a reverse spiral arrangement in the radial exterior of the stator (1).

10. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The stator core (2) includes a stacked stator core (18) having inner and outer stator slots (19, 20) that extend spirally corresponding to the threads of the anti-torsional rigid winding (3), wherein the inner stator slot (20) extends radially inward of the stator (1) according to a first rotation direction, and the outer stator slot (19) extends radially outward of the stator (1) according to a second rotation direction, wherein the extension direction of the inner stator slot (20) is opposite to the extension direction of the outer stator slot (19).

11. The dual-rotor radial flux motor (10) as described in claim 10, characterized in that, The stacked stator core (18) includes an inner partial package (23) with the inner stator slot (20) and an outer partial package (24) with the outer stator slot (19), wherein the stator laminations (22) of the inner partial package (23) are designed to have the same geometry, and the stator laminations (21) of the outer partial package (24) are designed to have the same geometry, wherein the stator laminations (22) of the inner partial package (23) according to a first rotation direction of the conductor rod (6) and the stator laminations (21) of the outer partial package (24) according to a second rotation direction of the conductor rod (6) are stacked in such a way that they are twisted relative to each other about the central axis (M) by a predetermined torsion angle γ.

12. The dual-rotor radial flux motor (10) as described in claim 11, characterized in that, The total helix angle φ generated circumferentially by the permanent magnet (29) of the inner rotor (12) is within the range of 20% to 40% of the torsion angle γ of the stator lamination (22) of the inner partial package (23), and / or the total helix angle φ generated circumferentially by the permanent magnet (29) of the outer rotor (13) is within the range of 20% to 40% of the torsion angle γ of the stator lamination (21) of the outer partial package (24).

13. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The permanent magnets (29) of the inner rotor (12) and the permanent magnets (29) of the outer rotor (13) have a predetermined tangential width (37), wherein the stator core (2) has a radial yoke thickness (36) which is between 5% and 25% of the tangential pole width, wherein the tangential pole width is the common tangential width of all the permanent magnets (29) constituting the pole.

14. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The dual-rotor radial flux motor (10) is configured for use in a hub drive.

15. The dual-rotor radial flux motor (10) as described in claim 11, characterized in that, The total helix angle φ generated circumferentially by the permanent magnet (29) of the inner rotor (12) is within the range of 25% to 35% of the torsion angle γ of the stator lamination (22) of the inner partial package (23), and / or the total helix angle φ generated circumferentially by the permanent magnet (29) of the outer rotor (13) is within the range of 25% to 35% of the torsion angle γ of the stator lamination (21) of the outer partial package (24).

16. The dual-rotor radial flux motor (10) as described in claim 11, characterized in that, The total helix angle φ generated circumferentially by the permanent magnet (29) of the inner rotor (12) is within the range of 28% to 32% of the torsion angle γ of the stator lamination (22) of the inner partial package (23), and / or the total helix angle φ generated circumferentially by the permanent magnet (29) of the outer rotor (13) is within the range of 28% to 32% of the torsion angle γ of the stator lamination (21) of the outer partial package (24).

17. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The permanent magnets (29) of the inner rotor (12) and the permanent magnets (29) of the outer rotor (13) have a predetermined tangential width (37), wherein the stator core (2) has a radial yoke thickness (36) which is between 10% and 20% of the tangential pole width, wherein the tangential pole width is the common tangential width of all the permanent magnets (29) constituting the pole.

18. The dual-rotor radial flux motor (10) as described in claim 1, characterized in that, The permanent magnets (29) of the inner rotor (12) and the permanent magnets (29) of the outer rotor (13) have a predetermined tangential width (37), wherein the stator core (2) has a radial yoke thickness (36) which is in the range of 12.5% ​​to 17.5% of the tangential pole width, wherein the tangential pole width is the common tangential width of all the permanent magnets (29) constituting the pole.

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