Manufacturing a synchronous reluctance machine using additive manufacturing

Abstract

According to an aspect, a rotor for a synchronous reluctance motor (SynRM) is provided. The rotor core includes alternating layers of radially fabricated magnetic flux carrier material and magnetic flux barrier material to define a magnetic flux barrier extending through the core without a bridge and / or center post. In some embodiments, the alternating layers include layers of permanent magnet (PM) material and soft magnetic composite (SMC) material fabricated on and directly attached to a rotor shaft. A corresponding method for manufacturing a SynRM is also provided.

Description

Technical Field

[0001] The technical field generally relates to synchronous magnetoresistive engines, and more specifically to methods for manufacturing components of synchronous magnetoresistive engines. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) with rare-earth magnets are used in a wide range of applications, from home appliances to electric vehicles and wind turbines, because they offer high efficiency and torque density. Due to rising rare-earth prices, the electric motor industry is seeking alternative designs and technologies that reduce reliance on rare-earth elements without sacrificing motor performance. Synchronous reluctance motors (SynRMs) are considered a promising alternative to PMSMs due to their robust rotor design and performance comparable to conventional induction motors. While SynRMs can achieve power density and efficiency comparable to induction motors, their performance still falls short of PMSMs with rare-earth magnets. Therefore, there is room for improvement. Summary of the Invention

[0003] According to one aspect, a rotor for a synchronous reluctance motor (SynRM) is provided. The rotor includes: a shaft; and a core fixed relative to the shaft. The core includes alternating layers of radially manufactured flux carrier material and flux barrier material to define a flux barrier extending through the core without bridging elements and / or a central post. In an embodiment, the alternating layers include layers of permanent magnet (PM) material manufactured on and directly attached to the rotor shaft and layers of soft magnetic composite (SMC) material.

[0004] According to one aspect, a method for manufacturing a rotor for a SynRM is provided. The method includes the steps of: a) providing a support structure; b) manufacturing a first layer of magnetic flux carrier material on the support structure; c) manufacturing a layer of magnetic flux barrier material over the first layer of magnetic flux carrier material to define magnetic flux barriers; d) manufacturing a subsequent layer of magnetic flux carrier material over the layer of magnetic flux barrier material; and e) repeating steps c) and d) to form a rotor having a desired number of magnetic flux barriers. In an embodiment, the layers are formed by manufacturing PM and SMC materials using cold spray additive manufacturing. Attached Figure Description

[0005] Figure 1 This is a cross-sectional view of a conventional SynRM motor according to an exemplary embodiment.

[0006] Figure 2This is a diagram illustrating the impact of bridging components and center posts on the performance of SynRm motors.

[0007] Figure 3 This is a cross-sectional view of a segmented rotor according to an exemplary embodiment, in one quadrant.

[0008] Figure 4 This is a cross-sectional view of a PM auxiliary rotor according to an exemplary embodiment.

[0009] Figure 5 This is a quadrant cross-sectional view of an alternative SynRM motor based on an embodiment including an axially layered rotor.

[0010] Figure 6 This is a cross-sectional view of an axially layered rotor according to an embodiment, showing the parameters used to define the magnetic flux barrier structure.

[0011] Figure 7 It shows the Figure 6 A graph showing an exemplary result of optimizing the rotor parameters shown.

[0012] Figure 8 This is a cross-sectional view of an alternative SynRM motor according to an implementation including 8 poles.

[0013] Figure 9 This is a cross-sectional view of an axially layered rotor according to an alternative embodiment having notches defined on the rotor surface. Detailed Implementation

[0014] refer to Figure 1 The image shows a cross-section of a typical SynRM motor 100, which includes a stator portion 101 and a rotor portion 151. The stator portion 101 includes a stator core 103 made of a high-permeability material and includes a plurality of teeth 105 around which armature coils 107 are wound to generate an electromagnetic field and define a plurality of stator poles. The rotor portion 151 is positioned to rotate within the stator portion 101 about a central axis 150 on a rotor shaft 161 in response to the magnetic field generated by the stator portion 101. The rotor shaft 161 extends along a longitudinal axis corresponding to the central axis 150.

[0015] The rotor portion 151 includes a rotor core 153 made of a high-permeability material and a plurality of magnetic flux barriers 155 made of a non-magnetic material, which define magnetic flux paths through the rotor core 153. In this illustration, the magnetic flux barriers 155 are arcuate air gaps defined in the rotor core 153, extending between opposite radial ends of the rotor core 153. The rotor core 153 is laterally laminated, wherein it is formed by laminating a plurality of laminates along the longitudinal axis of the rotor shaft 161, each laminate extending laterally in a plane relative to the longitudinal axis of the rotor shaft 161. Each of these laminates is substantially identical, and the magnetic flux barriers 155 are etched into each laminate. In this configuration, a central post 157 and a bridging member 159 are provided to facilitate assembly and maintain the structural integrity of the rotor core 153. The central post 157 includes a portion of rotor core material intersecting the air gap of the flux barrier 155, and the bridging member 159 includes a portion of rotor core material spaced apart from the air gap of the flux barrier 155 and the radial ends of the rotor core 153. As can be understood, the post 157 / bridging member 159 allows components of each laminate to be held together as single pieces, facilitating assembly. Furthermore, the assembled laminate will have enhanced structural integrity, which is particularly desirable when the rotor core 153 is operating at high speeds.

[0016] While the center post 157 and bridging member 159 facilitate assembly and provide additional structural integrity, they can have a significant impact on the performance of the SynRM motor 100. As can be understood, the center post 157 and bridging member 159 increase leakage flux through the flux barrier 155 and result in a reduction in the motor's torque capability. Figure 2 As shown, finite element analysis (FEA) reveals that removing the bridge / center post has the potential to increase output torque by approximately 35% compared to a SynR motor with a 2mm bridge / center post. This effect is even more pronounced in cases where a thicker bridge / center post is required.

[0017] One way to counteract this effect is to provide a rotor core that does not have bridging elements and / or a center post, for example in Figure 3 The segmented rotor core 151a is shown. This can be achieved, for example, via axial laminations (i.e., providing laminations extending along an axis parallel to the longitudinal axis of the rotor shaft, radially stacking the laminations relative to the rotor shaft 161, and bonding the stacked laminations to the rotor shaft 161). However, it is understood that eliminating the bridging / center post in this way would result in each rotor lamination being divided into many different segments, thus complicating the assembly process and hindering mass production. Another way to counteract the effects of the bridging / center post is to insert permanent magnets 163 into the flux barrier 155, for example in... Figure 4 The permanent magnet (PM) assisted rotor core 151b is shown. The permanent magnet 163 can increase the magnetic flux density level in the region of the bridging member 157 / center post 159, thereby increasing the magnetic reluctance of the leakage flux path. However, the magnetic flux that contributes to generating torque is relatively low because a considerable portion of the total magnetic flux circulates within the rotor core, thus saturating the bridging member and center post.

[0018] Now for reference Figure 5 and Figure 6 The following diagram illustrates an alternative design for a SynRM motor 200, according to a possible implementation, comprising a stator portion 201 and a rotor portion 251 configured to not have a center column and / or bridging elements. The stator portion 201 includes a stator core 203 made of a high-permeability material and includes a plurality of teeth 205 around which armature coils 207 are wound to generate a magnetic field and define a plurality of stator poles. The rotor portion 251 is positioned to rotate within the stator portion 201 about a central axis 250 on a rotor shaft 261 in response to the magnetic field generated by the stator portion 201. The rotor shaft 261 extends along a longitudinal axis corresponding to the central axis 150. In the illustrated embodiment, one quadrant of the four-pole rotor 251 is shown. It is understood that other quadrants can be constructed in a similar manner. It is also understood that quadrants with more poles, such as in… Figure 8 The 8-pole rotor in the 200 electric motor provides a similar design.

[0019] Back Figure 5 and Figure 6 The rotor portion 251 includes a rotor core 253 made of a high-permeability material and includes a plurality of magnetic flux barriers 255 for defining magnetic flux paths through the core 253. In this embodiment, the magnetic flux barriers 255 are generally arc-shaped and extend between two points on the rotor surface 267, particularly between the spaced-apart first radial ends 267a and second radial ends 267b of the rotor core 253, extending generally symmetrically about an axis of symmetry 269. However, it is understood that other shapes and configurations of the magnetic flux barriers 255 are also possible.

[0020] The rotor core 253 is axially layered, comprising multiple layers, each extending along an axis substantially parallel to the longitudinal axis of the shaft 261. Specifically, the rotor core 253 is formed via alternating layers of flux carrier material 265 (i.e., core material) and flux barrier material 263. Layers 263 and 265 alternate in a radial direction relative to the shaft 261. The flux carrier material 265 may comprise a material with substantially high permeability, such as a material having a relative permeability much greater than 1 and preferably greater than 100. In this embodiment, the flux carrier material 265 comprises a soft magnetic composite material (SMC), but it is understood that other similar materials, such as soft magnetic materials, may be used in other embodiments. On the other hand, the flux barrier material 263 may comprise a material with substantially low permeability, such as a material having a relative permeability less than 100 and preferably close to 1. In this embodiment, the magnetic flux barrier material 263 includes a permanent magnet material, but it is understood that in other embodiments, the magnetic flux barrier material 263 may include a non-magnetic material and / or a combination of magnetic and non-magnetic materials.

[0021] The layers of rotor core 253 are arranged to prevent leakage flux between the flux paths defined by flux barriers 255. More specifically, in this embodiment, the layers of flux carrier material 265 are completely separated from each other by passing through corresponding layers of flux barrier material 263. In other words, each layer of flux barrier material 263 extends continuously and uninterruptedly along a thickness 273 between the outer radial boundary 271a of the first flux carrier layer and the inner radial boundary 271b of the second flux carrier layer. In this configuration, substantially no flux carrier material 265 extends within or through the layers of flux barrier material 263.

[0022] In this embodiment, the layers of the rotor core 253 can also be configured such that the rotor core 253 is essentially a solid mass. In other words, there are no air gaps or pockets between the inner surface 266 and the outer surface 267 of the rotor core 253, and the adjacent layers of the flux carrier material 265 and the flux barrier material 263 are continuous and completely attached to each other along their boundaries. In this way, the rotor core 253 essentially comprises a solid mass including magnets of complex shapes embedded in a soft magnetic material.

[0023] As can be understood, the various geometric properties of the layers can be adjusted according to the requirements of the rotor section 251. For example, the thickness 273 of the magnetic flux barrier layer and the thickness 275 of the magnetic flux carrier layer can vary from one embodiment to another. In some embodiments, for example... Figure 5As shown, each magnetic flux barrier layer may have the same or similar thickness 273, and / or each magnetic flux barrier layer may be spaced apart at the same distance (i.e., separated by magnetic flux carrier layers having the same or similar thickness 275). In other embodiments, such as... Figure 6 As shown, each magnetic flux barrier layer may have a different thickness 273 and / or may be spaced apart from each other at different distances or magnetic flux carrier thicknesses 275. In some embodiments, for example, as Figure 5 As shown, thicknesses 263 and 275 can be relatively uniform, resulting in, for example, the magnetic flux barrier 255 having a substantially uniform thickness along its path between the first radial end 267a and the second radial end 267b of the rotor core 253. In other embodiments, such as... Figure 6 As shown, thicknesses 263 and 275 can vary over a given layer, resulting in, for example, the magnetic flux barrier 255 having a varying thickness along its path between the first radial end 267a and the second radial end 267b of the rotor core 253. Furthermore, it is understood that the number of layers of magnetic flux barrier material 263 and magnetic flux carrier material 265 can vary. For example, in Figure 5 and Figure 6 In one embodiment, there are four layers of magnetic flux barrier material 263. In other embodiments, more or fewer layers of magnetic flux barrier material 263 may be provided depending on the desired number of magnetic flux barriers 255.

[0024] It is also understandable that the geometric properties can be adjusted to optimize the performance parameters of rotor 251. Figure 6 In the illustrated embodiment, the flux barrier layer and the flux carrier layer are each constructed as generally concentric arcs extending between spaced-apart first radial ends 267a and second radial ends 267b of the rotor core 253, symmetrical about axis 269. Angles α1 to α4 define the flux carrier angle at rotor surface 267, while angles β1 to β4 define the flux barrier angle at rotor surface 267. As can be understood, individually adjusting angles α1 to α4 and β1 to β4 will result in different rotor geometries that may have different properties. Accordingly, these eight parameters can be optimized to obtain desired performance characteristics. For example, in Figure 7The results shown demonstrate the application of a genetic algorithm to optimize eight parameters using an objective function aimed at minimizing torque ripple and maximizing average torque. During the optimization process, 1399 candidate designs were evaluated and simulated, resulting in 700 designs converging towards low torque ripple and high average torque. One of these designs can then be selected for production, for example, by choosing the design with the lowest torque ripple and the highest average torque. However, other factors, such as low magnet volume and / or low demagnetization risk, can also be considered when selecting the optimized design. It is understood that different optimization algorithms can be used to produce the desired design, and different performance parameters can be sought. It is also understood that a similar optimization process can be performed for different magnetic flux barrier constructions and using different optimization parameters.

[0025] Although in the above embodiment the magnetic flux barrier 255 extends to the rotor surface 267 (particularly between the first radial end 267a and the second radial end 267b of the rotor core 253), it is understood that other configurations are possible. For example, refer to Figure 9 An alternative configuration of rotor 251' is shown. In the illustrated configuration, the magnetic flux barrier 255 extends between a first end 279a and a second end 279b, which are radially spaced inward relative to rotor surface 267 by a distance ΔX. In this way, a small gap or notch 281 is defined at rotor surface 267 adjacent to the ends 279a, 279b of the magnetic flux barrier (i.e., at the first end 267a and the second end 267b of the rotor surface). In this embodiment, the notch 281 is an air notch; however, it is understood that any suitable non-conductive material can be used to fill the notch 281. As can be understood, magnets located near the armature may be more susceptible to irreversible demagnetization. Therefore, providing the notch 281 at the end of the magnetic flux barrier 255 located at rotor surface 267 helps prevent demagnetization of the magnetic flux barrier material 263. This can contribute to the stability of rotor performance under different operating conditions. This can also lead to reduced magnet eddy current losses and thus increased overall motor efficiency.

[0026] As can be understood, the aforementioned axially layered rotor core 253 can possess good magnetic and mechanical properties. However, this axially layered rotor core 253 is also suitable for mass production because it can be manufactured using different additive manufacturing techniques involving the alternating fabrication of layers of magnetic flux carrier material and layers of magnetic flux barrier material to obtain the final structure. For example, refer to… Figure 5 , Figure 6 and Figure 9A method for manufacturing an axially layered rotor core 253 may include the following steps: a) providing a support structure; b) manufacturing a first layer of flux carrier material 265 on the support structure; c) manufacturing a layer of flux barrier material 263 over the previous layer of flux carrier material 265 to define flux barriers 255; d) manufacturing subsequent layers of flux carrier material 265 over the layers of flux barrier material 263; e) repeating steps c) and d) to form a rotor core 253 having a desired number of flux barriers 255. The manufactured rotor core 253 may then be joined or fastened to a rotor shaft 261 and / or otherwise mounted relative to a stator 101 to form an electric motor 200. In some embodiments, manufacturing layers of flux barrier material and / or flux carrier material may include depositing flux barrier material and / or flux carrier material on the support structure and / or depositing it over a previous layer of flux barrier material and / or flux carrier material. In some embodiments, the first layer of flux carrier material 265 can be directly deposited, formed, or otherwise manufactured on the support structure, and subsequent layers of flux carrier material 265 and / or flux barrier material 263 can be deposited, formed, or manufactured on the first layer of flux carrier material 265. In some embodiments, in step c), the flux barrier material 263 can be deposited over the flux carrier material 265 such that the flux barrier material 263 completely covers the previous layer of flux carrier material 265 without leaving any air gaps in the body of the rotor core 253. In some embodiments, in step c), the flux barrier material 263 can be deposited over the flux carrier material 265 such that the flux barrier material 263 completely covers the previous layer of flux carrier material 265 between the first radial end 267a and the second radial end 267b of the rotor core 253. In other embodiments, in step c), a magnetic flux barrier material 263 may be deposited over a magnetic flux carrier material 265 between a first end 279a and a second end 279b, the first and second ends 279a and 279b being radially spaced inward relative to the first and second ends 267a and 267b of the rotor core 253 by a distance ΔX, thereby defining a notch 281 at the rotor surface 267. In some embodiments, the subsequent step f) may include machining the layered rotor core 253 to balance and / or refine the rotor surface 267 (e.g., by removing at least some of the magnetic flux barrier material 263 to define the notch 281) or to refine the shaft interface, thereby achieving, for example, desired fine machining and / or ensuring proper fit with the stator 201. In some embodiments, a support structure may correspond to the rotor shaft 261. Accordingly, in these embodiments, the first layer may be directly fabricated, deposited, or formed on the rotor shaft 261.

[0027] In this embodiment, the flux barrier material 263 is a magnetic material. When the layers of flux barrier material 263 are fabricated in step c), the material 263 is not magnetized. Accordingly, additional steps may include magnetizing the flux barrier material 263. In this embodiment, the step of magnetizing the flux barrier material 263 is performed after step e) (i.e., after rotor assembly). However, it is understood that in other embodiments, magnetization can be performed at any time after the fabrication of one or more layers of barrier material 263. Magnetizing the flux barrier material 263 may include applying a magnetic field to one or more layers of flux barrier material 263. As can be understood, the required magnetization of the flux barrier 255 can vary based on the rotor construction and the materials used, and different magnetic field strengths may be required to fully magnetize all flux barrier layers. In this embodiment, the flux barrier 255 is magnetized by the armature coils 207 of the stator 201. More specifically, the motor 200 is a three-phase motor, and magnetization is performed by applying current through two phases (phase A and phase B) of the armature coil 207, with the rotor's direct axis (d-axis) aligned with the armature magnetic field. A current of at least 2,000 A is applied to the armature coil 207 to generate magnetic fields of at least 1,000 kA / m and 1,300 kA / m in each flux barrier of the flux barriers 255, thereby fully magnetizing the flux barrier material 263. However, it is understood that different currents can be used in different rotor and / or stator winding configurations. Furthermore, in some embodiments, the flux barrier material 263 can be magnetized by other magnetic field sources.

[0028] Different additive manufacturing techniques can be used to construct the rotor core 253, for example, by constructing layers of magnetic flux barrier material 263 and magnetic flux carrier material 265 radially relative to the central axis 250 and / or rotor shaft 261. In other words, each layer can be deposited, formed, or manufactured such that it is laminated in a radial direction relative to the central axis 250 and / or rotor shaft 261. Once the desired thickness of a given layer is reached, a different material for the next layer can be deposited, formed, or manufactured on that given layer. In this way, the layers 263, 265 of the rotor core 253 will alternate in a radial direction relative to the central axis 250 and / or rotor shaft 261. As can be understood, when constructing layers radially, each layer 263 and 265 can be deposited, formed, or manufactured along the length of the central axis 250 and / or rotor shaft 261 and around its periphery. In this way, the radially formed layers can be described as axial layers because they extend along an axis that is substantially parallel to the longitudinal axis of the central axis 250 and / or rotor shaft 261.

[0029] As can be understood, additive manufacturing allows for the formation of complex structures within the core 253, whereas conventional manufacturing techniques limit rotor structures to simple shapes. Furthermore, forming the core in this way allows the flux carrier 265 layer (e.g., manufactured using SMC) to receive 3D magnetic flux, and therefore magnetic flux in any direction. This contrasts with conventional laminates that only receive magnetic flux within the plane of the laminate. In this embodiment, cold spraying is used to deposit layers of alternating flux barrier material 263 and flux carrier material 265, comprising permanent magnet (PM) material and soft magnetic composite (SMC) material, respectively. However, it is understood that any type of additive manufacturing technique that allows for the construction of metallic structures can be used. For example, in addition to techniques such as molding and pressing, techniques such as large-area additive manufacturing, fused wire fabrication, laser sintering, binder jetting, and powder bed fabrication can also be used. It is also understood that various spray-based manufacturing techniques (i.e., any technique involving the controlled deposition of layers or coatings using atomized and / or particulate matter) can be used, such as aerosol spraying, high-velocity air fuel (HVAF), high-velocity oxygen fuel (HVOF), or other thermal spraying techniques. Furthermore, it is understood that combinations of different techniques can be used. For example, the first layer of SMC can be directly pressed onto the rotor shaft, while subsequent layers are built onto the first layer of SMC using a spray-based manufacturing technique. Finally, it is understood that different combinations of materials can be used, such as composite materials from the following families, including any alloys and / or mixtures thereof: a) permanent magnets: ferrite, neodymium iron boron, samarium cobalt, and alnico; and b) SMC: pure iron, cobalt iron, ferrosilicon, or any of such materials obtained from powder surrounded by an organic or inorganic insulating layer. Those skilled in the art will recognize that the various properties of these materials can be adapted to the applications by including other elements.

[0030] In the description provided above, exemplary embodiments of the rotor structure and methods of manufacturing thereon have been provided. It is understood that these embodiments are provided for illustrative purposes only and should not be considered as limiting the scope of the invention. For example, it should be understood that minor modifications and substitutions can be made to the above-described construction without departing from the scope of the invention. It should also be understood that the layered structure of the described motor can be applied to other structures with similar requirements, such as stators or rotors of different shapes. Finally, it should be understood that although the invention is described with respect to electric motors, similar principles and structures can be used in conjunction with other types of motors.

Claims

1. A method for manufacturing a rotor for a synchronous reluctance motor (SynRM), the method comprising: a) Provide a shaft extending along the longitudinal axis; b) Form a first layer of magnetic flux carrier material on the shaft; c) A layer of magnetic flux barrier material is formed above the previous magnetic flux carrier material to define the magnetic flux barrier; d) Form a subsequent layer of magnetic flux carrier material on top of the layer of magnetic flux barrier material; e) Repeat steps c) and d) to form a rotor core with the desired number of magnetic flux barriers. The magnetic flux barrier material layer and the magnetic flux carrier material layer are formed using additive manufacturing, thereby allowing the magnetic flux barrier to extend through the rotor core without bridging components.

2. The method according to claim 1, wherein, The layers of magnetic flux barrier material and the layers of magnetic flux carrier material are formed radially relative to the longitudinal axis of the shaft.

3. The method according to claim 1, wherein, In step c), the layer of magnetic flux barrier material is formed to completely cover the previous layer of magnetic flux carrier material between the first end and the second end, thus defining a complete separation between the layers of the magnetic flux carrier material.

4. The method according to claim 1, wherein, The layer of magnetic flux barrier material is formed between a first end and a second end, the first end and the second end being radially spaced inward relative to the outer surface of the rotor core.

5. The method according to claim 1, wherein, Spray-based additive manufacturing is used to deposit layers of the magnetic flux barrier material and the magnetic flux carrier material.

6. The method according to claim 1, wherein, The magnetic flux carrier material includes soft magnetic composite (SMC) material or soft magnetic material.

7. The method according to claim 1, wherein, The magnetic flux carrier material is selected from pure iron, cobalt iron, silicon iron, and any such material obtained by coating the surrounding area with organic or inorganic insulating powder.

8. The method according to claim 1, wherein, The magnetic flux barrier material includes permanent magnet (PM) material.

9. The method according to claim 1, wherein, The magnetic flux barrier material is selected from: ferrite, neodymium iron boron, samarium cobalt, alnico, alloys of the above, and mixtures of the above.

10. The method according to claim 1, further comprising the steps of: processing the rotor core to balance the rotor core or refining the outer surface of the rotor core.

11. The method according to claim 10, further comprising: At least some of the magnetic flux barrier material is removed to define a notch on the outer surface of the rotor core.

12. The method according to claim 1, further comprising the step of magnetizing the magnetic flux barrier.

13. The method according to claim 12, further comprising: The rotor is positioned within the stator, and the magnetic flux barrier is magnetized using the windings in the stator.

14. The method according to claim 1, wherein, The first layer of magnetic flux carrier material is directly attached to the rotor shaft.

15. The method of claim 1, further comprising securing the rotor core relative to the rotor shaft.

16. A rotor manufactured by the method according to any one of claims 1 to 15.

17. A rotor for a synchronous reluctance motor (SynRM), the rotor comprising: a) A shaft extending along its longitudinal axis; as well as b) A rotor core formed on the shaft, the rotor core comprising alternating layers of magnetic flux barrier material and magnetic flux carrier material formed via additive manufacturing, such that a magnetic flux barrier defined by the magnetic flux barrier material extends through the rotor core without bridging, wherein the alternating layers of the magnetic flux barrier material and the magnetic flux carrier material extend parallel to the longitudinal axis and alternate between the magnetic flux barrier material and the magnetic flux carrier material in a radial direction relative to the shaft, and wherein a first layer of magnetic flux carrier material is formed directly on the shaft.

18. The rotor according to claim 17, wherein, The rotor core includes a body defined by the magnetic flux carrier material, the body including a plurality of magnetic flux barriers extending through the body to define magnetic flux paths.

19. The rotor according to claim 18, wherein, The magnetic flux barrier extends through the body without the central pillar or the bridging element.

20. The rotor according to claim 17, wherein, The layers of magnetic flux barrier material and the layers of magnetic flux carrier material together define a substantially solid block, with no cavities or air gaps between the inner and outer surfaces of the rotor core.

21. The rotor of claim 17, wherein the rotor includes a plurality of notches defined on the outer surface of the rotor core at the end of the magnetic flux barrier material.

22. The rotor according to claim 17, wherein, The layers of the magnetic flux carrier material are completely separated from each other by a corresponding intermediate layer of magnetic flux barrier material.

23. The rotor according to claim 17, wherein, Each layer of the magnetic flux barrier material extends continuously with a thickness between the outer radial boundary of the inner magnetic flux carrier layer and the inner radial boundary of the outer magnetic flux carrier layer.

24. The rotor according to claim 17, wherein, The layers of magnetic flux barrier material and the layers of magnetic flux carrier material are formed radially relative to the longitudinal axis of the shaft.

25. The rotor according to claim 17, wherein, Cold spray additive manufacturing is used to deposit layers of the magnetic flux barrier material and the magnetic flux carrier material.

26. The rotor according to claim 17, wherein, The magnetic flux carrier material includes SMC material or soft magnetic material.

27. The rotor according to claim 17, wherein, The magnetic flux carrier material is selected from pure iron, cobalt iron, silicon iron, and any such material obtained from powder coated with an organic or inorganic insulating layer.

28. The rotor according to claim 17, wherein, The magnetic flux barrier material includes PM material.

29. The rotor according to claim 17, wherein, The magnetic flux barrier material is selected from: ferrite, neodymium iron boron, samarium cobalt, alnico, alloys of the above, and mixtures of the above.

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