This invention relates generally to the technical field of electric motors, in particular it relates to a rotor of an electric motor, in detail of a synchronous reluctance motor. More specifically, the invention relates to a method of producing a rotor for a synchronous reluctance motor.

In recent decades, the field of electric motors has acquired more and more importance and interest, both for the versatility of this type of motor and due to environmental issues.

Traditionally, electric motors consist of a rotor mounted in a rotatable way inside a stator. One or both of these components are configured to generate a magnetic field, for example through the use of permanent magnets or electric windings, wherein this magnetic field is configured to generate a rotation of the rotor with respect to the stator.

The motors thus obtained are advantageous from many points of view, being characterised by high efficiencies and high torque values.

There is a currently a great deal of interest in reducing costs and further increasing the efficiencies of such electric motors.

Furthermore, the costs of the rare earths of which the magnets of electric motors are made and the market stability of these elements are difficult to predict and represent a major disadvantage of such motors.

An alternative to traditional electric motors, which is capable of at least partially solving these problems, is represented by synchronous reluctance electric motors, which comprise rotors characterised by a robust and relatively simple structure, without cages and windings, and therefore characterised by the absence of losses due to the presence of copper and consequently the absence of possible increases in temperatures. Furthermore, the rotors of these motors can also be characterised by the absence of permanent magnets, thus reducing their production costs. This makes reluctance machines an alternative which is often very advantageous with respect other types of electrical machines.

The reluctance motor is a synchronous type of motor in which the torque is generated through the reluctance phenomenon. In detail, the salience of the rotor is formed with the introduction of flux barriers inside the rotor itself which are configured to direct the magnetic flux generated by the stator along the direct axis. During the operation of a synchronous reluctance motor, the rotor tends to align itself with the magnetic field produced by the stator poles. In particular, the rotor, behaving like a magnetic dipole, is subject to opposing forces at the ends along the longitudinal direction (direct axis "d"), proportional to the misalignment from the magnetic field: torque occurs if there is an angle between this direction and the direction of the magnetic field generated by the stator poles.

More specifically, like traditional electric motors, synchronous reluctance motors comprise an external stationary stator and an internal rotor, mounted rotatably with respect to the stator. The latter comprises a plurality of pairs of salient poles, formed, in use, by a current flowing in magnetic windings arranged in protuberances of the stator itself. The rotor is made of ferromagnetic material and includes a plurality of flux barriers, consisting of the alternation of segments of magnetic and non-magnetic material, which are configured to intercept a magnetic field produced by a pole of the stator and oppose a passage of that magnetic field through them and to direct the flux of the magnetic field along a first axis, or direct axis, coinciding with the direction of least reluctance. According to a configuration wherein a magnetic field of the stator is aligned with the flux barriers of the rotor, the latter is in a position of least reluctance, that is to say, the quantity of magnetic resistance is minimal. Conversely, according to a configuration wherein a magnetic field generated by a pole of the stator is not aligned with the flux barriers of the rotor, the latter is in the position of maximum reluctance. By the law of conservation of energy, the rotor will always tend to move towards the position of least reluctance, thus creating torque produced when the rotor is in the position of maximum reluctance.

In other words, the rotor of synchronous reluctance motors is configured to provide the least magnetic resistance in a first direction, in particular along a direct axis d, and a high reluctance, that is to say, a high magnetic resistance in a second direction, in particular along the quadrature axis q. In this sense, the torque is produced when the rotor attempts to align the first direction to the magnetic field of the stator.

The performances of the synchronous reluctance motors therefore depend mainly on the ratio between the inductances of the direct and quadrature axes. For a particular rotor design, this ratio is the result of parameters related to the geometry of the flux barriers in the rotor.

In order to produce the rotors of synchronous reluctance motors, and in particular the configuration of the flux barriers of these rotors, two main technologies are traditionally used: the axial lamination of these rotors and the transversal lamination of these same motors.

In detail, the configuration obtained through transversal lamination is the most widespread in the production of synchronous reluctance motors, especially since the construction of an axially laminated rotor involves several disadvantages which result in a product that is often not convenient.

Axial lamination rotors, thanks also to the possibility of forming a large number of flux barriers, are characterised by very limited losses that allow high efficiency motors to be obtained, in addition to the ability to reach very high salience ratios that allow to a high power factor to be obtained.

The main disadvantage of these axial lamination rotors, however, lies precisely in their production technique. A series of pre-formed laminations must be supplied and assembled using non-magnetic material as a separator, in order to define the flux barriers. This results in a particularly expensive process on the one hand, and which, on the other hand, can produce mechanical asymmetries that could compromise the balance of the machine. Furthermore, a non-trivial aspect still to be currently resolved concerns the fixing of the various laminations to the shaft, a problem which is particularly felt in high-speed motors. Lastly, it must be considered that, since the structure of the rotors with axial lamination is made up of different layers of pre-formed lamination, the flux barriers are composed of a plurality of rectilinear segments. This configuration of the flux barriers is not the optimal one for the maximising of salience.

In order to resolve these problems, the rotors of the synchronous reluctance motors can be transversely laminated, while renouncing the high number of flux barriers of rotors with axial lamination. The main advantage of this configuration lies in the fact that the laminations are obtained by punching, in a similar manner to what happens for the stator and rotor of induction machines. For this reason, the production costs are considerably limited and the rotor thus obtained is well balanced and symmetrical. On the other hand, the main disadvantage of this technique is the limited number of flux barriers, which limits the salience of the rotor and, consequently, the performance of the engine. This limitation mainly arises from the punching process.

The invention therefore starts from the technical problem of providing a method of producing a rotor for a synchronous reluctance motor that allows the above-mentioned needs with reference to the prior art to be met and to overcome the above-mentioned drawbacks and/or to achieve further benefits to be achieved. This is achieved by a method of producing a rotor for a synchronous reluctance motor and a synchronous reluctance motor according to the respective independent claims. Secondary features of the invention are defined in the corresponding dependent claims.

The invention relates to a method of producing a rotor for a synchronous reluctance motor comprising a stator having a plurality of poles. The method comprises a step of providing a support base. Preferably, the support base is configured to support at least a portion of said rotor. In other words, the support base is a base for supporting the rotor.

The method further comprises a step of making, by means of additive manufacturing, on the support base, for each pole of the stator, a plurality of wall elements arranged in sequence with each other along a radial direction. In other words, this step comprises producing, on the support base, a plurality of wall elements for each pole of the stator. The wall elements of each plurality of wall elements are arranged in sequence with each other along a radial direction. Preferably, each plurality of wall elements is arranged circumferentially with respect to the further plurality of wall elements on the support base. For example, the method can comprise making four pluralities of wall elements, one for each pole of the rotor, and consequently of the stator, wherein said four pluralities of wall elements are arranged circumferentially on the support base. In other words, the plurality of wall elements are arranged circumferentially on the support base, preferably to form a circle around a centre of the support base itself. In detail, this plurality of wall elements are made and arranged so as to define a plurality of gaps, or flux barriers, each arranged between consecutive wall elements along the radial direction. Each of these gaps, or flux barriers, is configured to block, or obstruct, a magnetic flux generated, in use, by one pole of the plurality of poles of the stator. Advantageously, therefore, by making the plurality of wall elements, and consequently the gaps, or flux barriers, through additive manufacturing, it is possible to make shaped flux barriers, in such a way that the rotor has the maximum salience. In other words, it is possible to obtain flux barriers having a shape suitable for following the flux barriers of the magnetic field generated by the stator, unlike what happens in the rotors with axial lamination. Moreover, by means of this technique, it is possible to overcome the disadvantages of the limited number of flux barriers of the rotors with transversal lamination. Advantageously, the fact that said plurality of wall elements are made by additive manufacturing, for example metal additive manufacturing, allows these wall elements to be produced, and in general a rotor of an electric motor, which is substantially in a single block. This results in a considerable simplification of forming said wall elements and of a rotor in general, as well as an improved simplification of assembly of an electric motor. Additive manufacturing also allows a precise shaping of the wall elements and consequently of the gaps.

The method further provides for a step of associating the plurality of wall elements together, preferably in at least the radial direction. Preferably, this association in the radial direction of the plurality of wall elements can be obtained through the support base. In other words, this step comprises associating, or structurally connecting, the wall elements of each plurality of wall elements, preferably in a radial direction.

Preferably, according to an aspect of the invention, the step of producing the plurality of wall elements by means of additive manufacturing can be carried out in such a way as that each gap, or flux barrier, is shaped so as to intercept flux lines generated, in use, by the plurality of poles of the stator. Preferably, this step can be carried out in such a way that the gaps, or flux barriers, are substantially shaped like a "C" or an arch. In other words, this step provides for an ideal configuration of the flux barriers, in such a way as to maximise the salience of the rotor.

According to a preferred aspect of the invention, the method can provide a step of shaping, preferably by laser, each wall of the plurality of walls so that each gap, or flux barrier, is shaped so as to intercept magnetic flux lines generated, in use, by the plurality of poles of the stator. Advantageously, this allows an ideal conformation of the flux barriers to be obtained. More preferably, this step of shaping each wall of the plurality of walls takes place through additive manufacturing, preferably through selective laser melting of metals, which allows a precise and ideal conformation of the walls to be obtained, and consequently of the flux barriers, by means of a single process. Furthermore, preferably, this step of shaping each wall of the plurality of walls can coincide with the step of making, for each pole of the stator, or for each pole of the rotor, on the support base, the plurality of wall elements.

According to a further preferred aspect of the invention, the step of associating the wall elements together can comprise providing at least one connecting layer configured to associate each wall element with at least one other wall element along the radial direction. In other words, the step of making the wall elements by additive manufacturing comprises making each wall element, from said support base, along a main direction of extension of said wall elements. Instead of associating these wall elements together, the step comprises connecting each wall element with at least one further wall element along the radial direction, preferably orthogonal to the main direction of extension. According to a further preferred aspect, the step of associating the wall elements together can comprise providing a layer of epoxy resin in each gap, or flux barrier. This epoxy resin layer is configured to associate two consecutive wall elements.

According to a further aspect, the step of associating the wall elements with each other can comprise making, preferably during the making of the wall elements, by means of additive manufacturing, a connecting structure between consecutive wall elements, or successive ones in a radial direction. This connecting structure can be configured to connect, at least along the radial direction, two consecutive wall elements of the plurality of wall elements. Advantageously, this step can therefore be carried out simultaneously with the production of the wall elements.

Preferably, according to a preferred aspect of the invention, the method can provide a step of inserting at least one permanent magnet in at least one gap, or flux barrier, of the plurality of gaps. Advantageously, it is therefore possible to increase the power factor of a synchronous reluctance motor comprising a rotor formed in this way.

According to a further preferred aspect of the invention, the step of making a plurality of wall elements so as to define a plurality of gaps, or flux barriers, can be configured for, or can comprise, making or defining a number of gaps of between 8 and 30, preferably a number of gaps of between 13 and 26. For example, this step is configured to define at least 13 gaps, or flux barriers, preferably 26 gaps, or flux barriers. It advantageously follows that the number of flux barriers that can be obtained can be high, as in the rotors made by axial lamination.

According to a preferred aspect of the invention, the step of making, for each pole of the stator, a plurality of wall elements arranged in sequence with each other along a radial direction in such a way as to define a plurality of gaps by means of additive manufacturing is carried out in such that each wall element of the plurality of wall elements has, in a direction orthogonal or substantially orthogonal to said radial direction, a helical or substantially helical extension. In other words, this step of making for each pole of the stator a plurality of wall elements is carried out in such a way that each of these has, in a direction substantially orthogonal to a plane of extension of the support base, a helical or substantially helical extension. Advantageously, a rotor thus obtained, in use, allows the creation of an air flow, thanks to the helical shape of the wall elements, and in particular of the gaps, or flux barriers, defined by these wall elements, which allows, in use, a cooling of a synchronous reluctance motor comprising such a rotor. Furthermore, this configuration of the wall elements has the advantage of improving the torque ripple. The invention also relates to a rotor for a synchronous reluctance motor made using the method according to the invention.

The invention also relates to an electric motor comprising a rotor for a synchronous reluctance motor made using the method according to the invention.

Further advantages, characteristics and methods of use of the object of the invention will become evident from the following detailed description of its embodiments, presented merely by way of non-limiting examples.

It is however evident that each embodiment of the object of the invention can have one or more of the advantages listed above; however, no embodiment is required to simultaneously have all the listed advantages.

Reference will be made to the accompanying drawings, wherein:

- Figure 1 shows a sectional view of a synchronous reluctance motor comprising a rotor for a synchronous reluctance motor according to an aspect of the invention;

- Figure 2 shows a perspective view of a portion of a rotor according to an aspect of the invention;

- Figure 3 shows a further perspective view of a portion of a rotor according to an aspect of the invention.

The invention relates to a method of producing a rotor 100 for a synchronous reluctance motor 1000 which comprises a stator 200 having a plurality of poles.

In particular, the method according to the invention comprises a step of providing a support base 10, or support structure. Preferably, this support base 10 is configured to support, preferably temporarily, the rotor 100 according to the invention, or at least a portion thereof. Preferably, the support base 10 can be configured to be removed once the rotor 100 according to the invention has been made.

With particular reference to Figures 2 and 3, the method according to the invention provides for the formation, on the support base 10 and for each pole of a stator 200, of a plurality of wall elements 20 arranged in sequence with each other along a radial direction A. In detail, starting from the support base 10, the method comprises producing a plurality of wall elements 20, which extend as mentioned from said support base 10 along a main direction of extension B of the wall elements.

In other words, the method provides for producing a plurality of wall elements 20 for each single pole of a stator 200. That is to say, in the case of a stator 200 comprising four poles, the method provides for making four pluralities of wall elements 20, that is to say, a plurality of wall elements 20 for each pole of the stator 200, wherein the four pluralities of wall elements 20 are suitably arranged together to form a rotor 100. Similarly, in the case of a stator 200 comprising six poles, the method provides for making six pluralities of wall elements 20, that is to say, a plurality of wall elements 20 for each pole of the stator 200, wherein the six pluralities of wall elements 200 are suitably arranged together to form a rotor 100. The method provides for arranging these different pluralities of wall elements 20 on the support base 10 so as to form a plurality of poles of said rotor 100. Preferably, these different pluralities of wall elements 20 can be associated with each other and associated with a shaft of the rotor 100 itself.

Preferably, the plurality of wall elements 20 as a whole defines a main body of the rotor 100 for a synchronous reluctance motor 1000. In other words, the wall element assembly constitutes a rotor 100 for a synchronous reluctance motor 1000.

Furthermore, this step provides for the arrangement of said plurality of wall elements 20 in sequence with each other, along a radial direction A. Preferably, this radial direction A is orthogonal or substantially orthogonal to a main direction of extension B of the plurality of wall elements 20. In other words, the step of making a plurality of wall elements 20 on the support base 10 provides for making, or arranging, several wall elements 20a, 20b, 20c side by side and successive along a radial direction A, wherein said plurality of wall elements 20 defines the main body of the rotor 100.

This step of forming on the support base 10 this plurality of wall elements 20 arranged in sequence with each other along the radial direction A is carried out by additive manufacturing, or production in layers. In other words, each wall element 20a, 20b, 20c of the plurality of wall elements 20 is made by adding a layer of material on top of the other, preferably starting from a computer-designed three-dimensional model. In other words, the main body of the rotor 100 is made of superimposed layers of material, in particular superimposed along the main direction of extension B of the wall elements. This method of manufacturing the wall elements has the advantage of being able to precisely define the shape of the rotor, in particular of the wall elements. Specifically, unlike the lamination, it is therefore possible to precisely define the arrangement and the number of flux barriers defined below.

Even more specifically, preferably the formation of the wall elements is carried out by means of metal additive manufacturing, preferably with Powder Bed Fusion technology, wherein a beam of laser or electronic energy is used to selectively melt a layer of powder of material configured for constitute the wall elements, or the main body of the rotor. Advantageously, this technology allows components to be made with a high geometric complexity. Preferably, the plurality of walls, or the main body of the rotor 100, is made of ferromagnetic material, preferably iron. In other words, the powder used in additive manufacturing is made of ferromagnetic material, preferably iron. Still more preferably, such powder comprises iron silicon or iron cobalt vanadium.

The step of making the plurality of wall elements 20 arranged in sequence along the radial direction A is carried out in such a way as to define a plurality of gaps 30, or flux barriers. In detail, each gap 30a, 30b, 30c, or flux barrier, is arranged between consecutive wall elements of the plurality of wall elements 20 along the radial direction A. In other words, two wall elements arranged consecutively along this radial direction A define between them a gap, or flux barrier. Each gap 30a, 30b, 30c, or flux barrier, of the plurality of gaps 30, or flux barriers, is configured to block, or obstruct, a magnetic flux generated, in use, by a pole of the plurality of poles of the stator 200.

Preferably, each gap 30a, 30b, 30c of the plurality of gaps 20 is shaped so as to follow the magnetic flux generated, in use, by a pole of the stator 200. Specifically, according to a preferred aspect of the invention, each gap 30a, 30b, 30c, or flux barrier, of the plurality of gaps 20, or flux barriers, is substantially shaped like a "C", so as to intercept lines of magnetic flux generated, in use, by a pole of the stator 200. In other words, each gap 30a, 30b, 30c, or flux barrier, can be substantially arch-shaped. It follows that, according to this aspect, each wall element of the plurality of wall elements 20 can be shaped like a "C" or an arch.

Even more specifically, more preferably, for each pole of the stator 200, the method provides for arranging a plurality of wall elements 20a, 20b, 20c in such a way as to define a first plurality of gaps 31 , or flux barriers, and a second plurality of gaps 32, or flux barriers, wherein said second plurality of gaps 32, or flux barriers, is successive, or arranged consecutively, along the radial direction A, with respect to the first plurality of gaps 31 , or flux barriers. In other words, the second plurality of gaps 32, or flux barriers, is external, along the radial direction A, with respect to the first plurality of gaps 31 , or flux barriers. In detail, preferably, each gap, or flux barrier, of the second plurality of gaps 32, or flux barriers, is substantially shaped like a “C” or arch-shaped. Preferably, moreover, each gap, or flux barrier, of the first plurality of gaps 31 , or flux barriers can comprise a first portion 31a and a second portion 31 b substantially arch-shaped, and a connecting portion 31c, configured to connect the first portion 31 a and the second portion 31b, wherein said connecting portion 31c is substantially straight. Therefore, the method according to the invention can preferably provide for the formation, for each pole of the stator 200, of a plurality of wall elements 20 arranged and shaped in such a way as to define a first plurality of gaps 31 , or flux barriers, and a second plurality of gaps 32, or flux barriers, as described.

In particular, with particular reference to the accompanying drawings, Figure 1 shows a sectional view of a synchronous reluctance motor 1000 comprising a stator 200 and a rotor 100 obtained through the method according to the invention. In detail, Figure 1 shows a plurality of flux barriers 30 for each of four poles of the stator 200. In particular, for each pole of the stator 200, Figure 1 shows thirteen gaps 30, or flux barriers, wherein each gap, or flux barrier, is shaped in an optimum manner, preferably to follow the flux of magnetic field generated, in use, by each pole of the stator 200. As can be seen, for each pole of the stator 200, the method comprises providing a second plurality of gaps 32, or flux barriers, substantially C-shaped, and a first plurality of gaps 31 , or flux barriers, wherein each gap, or flux barrier, of said first plurality of gaps 31 , or flux barriers, comprises a first portion 31a and a second portion 31b substantially arch-shaped, and a connecting portion 31c, configured to connect the first portion 31a and the second portion 31b, wherein the connecting portion 31c is substantially rectilinear.

According to a preferred aspect of the invention, the step of making on the support base 10, for each pole of the stator 200, a plurality of wall elements 20 arranged in sequence with each other along the radial direction A in order to define a plurality of gaps 20, or flux barriers, can also comprise a step of shaping each wall 20a, 20b, 20c of the plurality of walls 20 in such a way as to precisely shape each gap 30a, 30b, 30c, or flux barrier, of the plurality of gaps 30, or flux barriers. In detail, this shaping step comprises shaping each wall element 20a, 20b, 20c, so that each gap 30a, 30b, 30c is shaped in such a way as to intercept magnetic flux lines generated, in use, by the plurality of poles of the stator 200. Preferably, the step of shaping each wall element 20a, 20b, 20c of the plurality of wall elements 20 is carried out by means of a laser. In other words, this step comprises using a laser beam configured to shape the wall elements of the plurality of wall elements 20.

According to a preferred aspect of the invention, the step of making a plurality of wall elements 20 arranged in sequence along a radial direction A in order to define a plurality of gaps 30, or flux barriers, is configured to make, or define, a number of gaps 30, or flux barriers, of between 8 and 30, preferably of between 13 and 26. For example, this step is configured to define 13 gaps, or flux barriers, or 26 gaps, or flux barriers. In other words, according to this aspect, the method comprises making, in the rotor 100 and for each pole of the stator 200, between 8 and 30 gaps, or flux barriers, preferably between 13 and 26 gaps, or flux barriers.

Preferably, according to an aspect of the invention, the method can provide a step of inserting, in at least one gap, or flux barrier, of the plurality of gaps 30, or flux barriers, at least one permanent magnet. Advantageously, this makes it possible to obtain, in a motor 1000 comprising a rotor 100 made according to the invention, a better power factor.

The method according to the invention further comprises, for each pole of the stator 200, a step of associating with each other each wall element 20a, 20b, 20c of the plurality of wall elements 20. In other words, this step comprises connecting together, along the radial direction A, the wall elements of the plurality of wall elements 20. Preferably, this step comprises associating, or joining together, at least wall elements arranged consecutively, or successively, along the radial direction A. In other words, this step comprises associating with each other at least wall elements configured to define, between them, a gap, or flux barrier, of the plurality of gaps 30. Advantageously, according to a preferred aspect of the invention, the association in the radial direction A of the plurality of support elements 20 can be obtained by means of the support base 10. In other words, the support base 10 can be configured to associate the plurality of wall elements 20 with each other in a radial direction.

Preferably, the step of associating the wall elements of the plurality of wall elements 20 with each other can comprise providing at least one connecting element 40 configured to associate each wall element of the plurality of wall elements 20 with at least one further wall element of the plurality of wall elements 20, along the radial direction A. Preferably, such at least one connecting element 40 can be made by additive manufacturing. Furthermore, according to a preferred aspect of the invention, such at least one connecting element 40 can comprise, or coincide with, said support base 10. In particular, as can be seen in Figure 2, the step of associating the plurality of wall elements 20 in the radial direction is carried out by means of the support base 10.

Preferably, such at least one connecting element 40 comprises a layer of solid material. Even more preferably, this connecting element 40, preferably comprising a layer of solid material, is an element shaped like a plate, having a main direction of extension orthogonal or substantially orthogonal to the main direction of extension B of each wall element of the plurality of wall elements 20. Preferably, moreover, such at least one connecting element 40 is arranged at an end portion 21 of each wall element of the plurality of wall elements 20. According to a preferred aspect, this step comprises arranging a first connecting element and a second connecting element, wherein the first connecting element is arranged opposite to said second connecting element with respect to the plurality of wall elements 20. In other words, the second connecting element is arranged at a second end portion 22 of each wall element of the plurality of wall elements 20. Preferably, according to this aspect, the first connecting element can coincide with, or comprise, the support base 10. It follows that, advantageously, the process of producing the rotor 100 can comprise the making of the plurality of wall elements 20 and of the at least one connecting element 40 substantially in a single step. According to this aspect, the method can also comprise a step of shaping, or defining, this support base 10, for example by means of a laser. Furthermore, preferably, the second connecting element can be made by additive manufacturing and can preferably be arranged opposite the support base 10 with respect to the plurality of wall elements 20.

Preferably, the connecting element 40 is configured to join, for each pole of the stator 200, all the wall elements of the plurality of the wall elements 20. Preferably, both the first connecting element and the second connecting element are configured to join, for each pole of the stator 200, all the wall elements of the plurality of the wall elements 20. Furthermore, preferably, the connecting element 40 is configured to join all the wall elements of the plurality of wall elements 20 of all the poles of the stator 200. In other words, each wall element 20a, 20b, 20c of the plurality of wall elements 20 made for each pole of the stator 200 is associated, or joined, through the at least one connecting element 40, to the other wall elements of the plurality of wall elements 20 made for each pole of the stator 200.

The step of associating the wall elements of the plurality of wall elements 20 with each other can comprise arranging a layer of non-magnetic material in each gap 30a, 30b, 30c, or flux barrier, of the plurality of gaps 30, or flux barriers. Preferably, this layer of nonmagnetic material in each gap, or flux barrier, is configured to associate two wall elements of the plurality of wall elements 20 which define the gap or flux barrier. For example, such non-magnetic material can comprise epoxy resin.

According to a further aspect of the invention, the step of associating the wall elements of the plurality of wall elements 20 to each other can comprise making, preferably during the step of making on the support base of the plurality of wall elements 20, and preferably by additive manufacturing, a connecting structure between consecutive wall elements of the plurality of wall elements 20. This connecting structure is preferably configured to connect, at least along the radial direction A, at least two consecutive wall elements of the plurality of wall elements 20 arranged consecutively. For example, this step can preferably provide for the formation of a honeycomb structure inside the gaps 30a, 30b, 30c, or flux barriers.

If the at least one connecting element 40 does not include, or does not coincide with, the support base 10, for example if the latter is not made of ferromagnetic material, the method can also comprise a step for removing said base support 10. Preferably, according to this aspect, the method then provides for associating said plurality of wall elements 20 by means of such at least one connecting element 40.

According to a preferred aspect of the invention, the step of making, for each pole of the stator 200, a plurality of wall elements 20 arranged in sequence with each other along the radial direction A in such a way as to define a plurality of gaps 30 by means of additive manufacturing is carried out in such that each wall element of the plurality of wall elements 20 has, in a direction orthogonal or substantially orthogonal to said radial direction, a helical or substantially helical extension. In other words, this step is carried out in such a way that, starting from the support base 10, each wall element of the plurality of wall elements 20 has a helical extension along a direction orthogonal, or substantially orthogonal, to a plane defined by the same support base 10. Preferably, this direction coincides with the main direction of extension B of the wall elements.

In detail, the making of the wall elements through additive manufacturing comprises arranging, starting from the support base 10, a plurality of layers of material configured to make the wall elements, wherein the plurality of layers are arranged consecutively, or superimposed on each other, along the main direction of extension B of the wall elements. Each layer of this plurality of layers is configured to define at least a portion of at least one wall element of the plurality of wall elements 20. According to this aspect of the invention, successive layers, or layers superimposed on each other, are arranged, or positioned, out of phase with each other by an angle a in the plane defined by the support base 10. In this way, each wall element of the plurality of wall elements 20 will have, in the main direction of extension B of the same wall elements, a helical or substantially helical extension.

The invention relates to a rotor 100 for a synchronous reluctance motor 1000, wherein said rotor 100 is produced using the method previously described.

Lastly, the invention also relates to a reluctance motor 1000 comprising a stator 200 and a rotor 100 produced according to the method described above. The invention, described according to preferred embodiments, allows the set aims and objectives to be achieved for overcoming the limits of the prior art.

The object of the invention has thus far been described with reference to its embodiments. It is to be understood that there may be other embodiments pertaining to the same inventive core, all falling within the scope of protection of the claims set forth below.