Method for obtaining rotor for rotating electrical machine

Abstract

The invention relates to a method for obtaining a rotor (1) of a rotary electric machine comprising a rotor body (2), a magnetic element and a ring (6), the obtaining method comprising a step of positioning the rotor body (2) in an injection mold (42) and a step of placing the ring (6) in the injection mold (42) such that the ring (6) is placed around the rotor body (2), and a step of injection molding a magnetic element in the form of a bonded magnet (4) between the rotor body (2) and the ring (6).

Description

Technical Field

[0001] The present invention relates to the field of motor vehicles and, more particularly, to electric machines with which these motor vehicles are equipped. Background Art

[0002] Electric or hybrid motor vehicles are equipped with a rotating electrical machine, in particular an electrical machine having at least a stator and a rotor. In some of these rotating electrical machines, coils associated with the stator generate, when supplied with electric power, a magnetic flux that allows a rotor equipped with magnets to rotate. In radial flux rotating electrical machines, the magnetic flux is generated in a radial direction relative to the axis of rotation of the electrical machine, and the rotor rotates around the axis of rotation according to the orientation of the radial magnetic field.

[0003] The rotor of these rotating electrical machines generally comprises a ring and a magnetic element. The ring makes it possible to hold the magnetic element of the rotor in place, in particular ensuring that it remains in place when the rotor rotates at high speeds. The ring comprises an inner radial wall, an outer radial wall and a bottom wall delimiting a housing which is open at the top to receive the portion of the magnetic element. The magnetic element is thus placed inside the ring, against the bottom of the ring.

[0004] The magnetic elements are usually solid magnets, which means that assembly operations are required to fix them to the rings. However, arranging the magnetic elements inside the rings and fixing them together are complex operations. In particular, it is difficult to control the dimensional tolerances between these two components. In addition, due to the many positioning and assembly operations, the manufacture of the rotor takes a long time and requires considerable investment. Summary of the invention

[0005] The present invention falls within this context and proposes a method for manufacturing a rotor, whereby the production of the rotor is simplified while reducing the number of operations required.

[0006] The invention thus has as main subject a method for obtaining a rotor for a rotating electrical machine comprising a rotor body, magnetic elements and a ring, the method comprising the following steps:

[0007] positioning a rotor body within an injection mold;

[0008] placing the ring around the rotor body in a manner forming an annular chamber;

[0009] A magnetic element in the form of a bonded magnet is injection molded in the annular chamber.

[0010] The method for obtaining according to the invention corresponds to the manufacture of a rotor intended to be integrated in a rotating electrical machine, in particular in a radial flux rotating electrical machine. The method for obtaining involves an injection mold having a cavity, inside which a rotor body and a ring are successively placed during a positioning step and a placement step, respectively. The step of positioning the rotor body is carried out before the step of placing the ring, or conversely, the step of placing the ring is carried out before the step of positioning the rotor body. The rotor body is positioned just close to the center pin of the injection mold, while the ring is placed along the outer edge of the injection mold. The rotor body and the ring are arranged so that they do not touch each other; in other words, there is a space between the two components after the positioning and placement steps. Since the rotor body and the ring have an annular shape, this space corresponds to an annular chamber.

[0011] Once the rotor body and the ring are arranged in the mold, the method of obtaining comprises an injection molding step during which the magnetic elements of the rotor, in this case the bonded magnets, are injection molded inside the injection mold in an annular chamber between the rotor body and the ring. The material constituting the bonded magnets then polymerizes so as to form, together with the rotor body and the ring, an assembly of parts rigidly fixed to one another.

[0012] The use of injection molding makes it possible to easily manage the position of the bonded magnets relative to the rotor body and the position of the rings. Specifically, the bonded magnets match the shape of the rotor body and the shape of the rings. Injection molding also makes it possible to dispense with the bottom wall of the rings, the bonded magnets being held in place by the injection mold during the obtaining process. In addition, injection molding makes it possible to combine positioning and assembly operations, which were previously separate during the production of rotors of the prior art.

[0013] According to an optional feature of the invention, the rotor body comprises a score, and a portion of the bonded magnet is inserted into the score on the rotor body during the injection molding step.

[0014] The notches on the rotor body are cutouts extending at least radially from the edge of the rotor body facing the ring. The notches have an annular shape. According to an embodiment, they extend over the entire circumference of the rotor body or over a portion of the circumference. When the bonded magnet is injection molded in the injection mold, it fills these notches.

[0015] According to an optional feature of the invention, the ring comprises a recess into which a portion of the bonded magnet is inserted on the ring during the injection molding step.

[0016] The notches on the ring are cutouts extending at least radially from the face of the ring facing the rotor body. The notches are not continuous along this inner surface of the ring; therefore, there are a plurality of notches arranged at a distance from each other along the same circumference of the ring inscribed in the inner surface of the ring facing the rotor body. When the bonded magnet is injection molded in the injection mold, it fills these notches.

[0017] According to an optional feature of the invention, the obtaining method comprises a step of pre-magnetizing the bonded magnet inside the injection mold, the pre-magnetizing step involving a coil arranged in the injection mold around the area where the ring is placed.

[0018] The coils are arranged equidistant from one another inside the injection mold. Their orientation depends on the type of magnetization sought; thus, the coils will be straight, i.e. parallel to the axis of rotation of the rotor, for magnetization according to the Halbach array, or, on the contrary, in the case of a tilted or twisted rotor, the coils will be tilted relative to the axis of rotation of the rotor. The pre-magnetization step has the purpose of orienting the magnetic charge of the bonded magnet made of a polymer material in which the particles or grains of magnetic material are embedded. Thus, these particles of magnetic material that contribute to the formation of the bonded magnet are oriented along the magnetic field lines defined inside the injection mold, which is located inside the magnetic field. When the polymer constituting the bonded magnet polymerizes, the position of its grains of magnetic material is fixed. The bonded magnet thus has a fixed magnetic orientation.

[0019] According to an optional feature of the invention, the obtaining method comprises the step of magnetizing the bonded magnet outside the injection mold.

[0020] The bonded magnets are remagnetized in such a way that they return their magnetic charge according to the previously defined orientation. To this end, the rotor body comprises indexing means making it possible to promote magnetization according to the angular sectors defined during premagnetization.

[0021] The operations of pre-magnetization and magnetization can occur at different locations. For example, pre-magnetization can be performed at the supplier and magnetization can be performed at the customer, and then the bonded magnets can undergo a demagnetization step between the pre-magnetization step and the magnetization step to facilitate their transportation.

[0022] The present invention also relates to a rotor of a rotating electrical machine, which can be manufactured according to the obtaining method as described above, the rotor having a rotation axis and comprising a rotor body and a ring arranged around the rotor body to form an annular chamber, and a bonded magnet arranged in the annular chamber.

[0023] The rotor according to the invention is intended to form part of a rotating electrical machine, such as a radial flux machine, so that it can be fitted in an electric or hybrid motor vehicle. The rotor body makes it possible to rigidly fix the bonded magnets to the drive shaft element of the rotating electrical machine. The ring has the function of holding the bonded magnets in place and preventing them from breaking when the rotor rotates at high speeds.

[0024] The rotor body, bonded magnets and rings are arranged in this order around the rotation axis of the rotor, which is a result of the initial arrangement of the rotor body and rings in the injection mold.

[0025] According to an optional feature of the invention, the bonded magnets comprise tabs extending inside the rotor body and / or ring in a plane perpendicular to the axis of rotation of the rotor.

[0026] In other words, the tabs of bonded magnets extend radially inside the rotor body and / or rings.

[0027] According to an optional feature of the invention, the tabs of the bonded magnets extend within scores on the rotor body.

[0028] According to an optional feature of the invention, the tabs of the bonded magnet extend within recesses in the ring.

[0029] The presence of a portion of the bonded magnet, ie its tab, in the notches on the rotor body and / or the ring makes it possible to limit the slippage between the various elements of the rotor during operation of the rotating electrical machine.

[0030] According to an optional feature of the invention, the ring has an annular shape.

[0031] In particular, unlike the rings of the prior art, the rings according to the invention have no bottom. Since the bonded magnet is injection molded, the function of such a bottom is to hold the bonded magnet in place, which is not actually necessary. Moreover, in the method of obtaining, the injection mold makes it possible to hold the bonded magnet in place.

[0032] According to an optional feature of the invention, the ring comprises at least one collar, preferably toothed, partially covering the bonded magnet.

[0033] The collar corresponds to the extra thickness of the ring extending towards the axis of rotation of the rotor.

[0034] In some embodiments, the collar is discontinuous along the circumference of the ring, which enhances the feasibility of the method for obtaining the rotor. The purpose of this discontinuity is to block the rotation of the ring on the bonded magnet during operation of the motor. Alternatively, the collar extends over the entire circumference of the ring.

[0035] According to an optional feature of the invention, the bonded magnets have axial end edges which contribute to forming an axial peripheral edge of the rotor.

[0036] The axial end edge delimits the bonded magnet in a direction parallel to the axis of rotation of the rotor. The axial peripheral edge delimits the rotor in a direction parallel to the axis of rotation of the rotor. It should be understood that the bonded magnet is at least partially exposed in the rotor. In other words, the bonded magnet is not completely covered by the ring, which has no bottom wall.

[0037] According to an optional feature of the invention, the rotor body comprises a first portion intended to be in contact with the drive shaft element and a second portion in contact with the bonded magnet, the rotor body comprising branches extending radially between the first portion and the second portion.

[0038] The first part and the second part have an annular shape. They are connected to each other by a branch of the rotor body. When viewed in a cross section in a plane perpendicular to the axis of rotation of the rotor, the branch extends from the first part in the form of a star. The presence of a branch connecting the first part and the second part instead of a solid body makes it possible to limit the weight of the rotor body.

[0039] According to an optional feature of the invention, the bonded magnet is made of ferrite or rare earth alloy and a non-magnetic binder material.

[0040] Rare earth alloys include, for example, neodymium, iron and boron. Non-magnetic materials are in particular resins, for example thermoplastics based on polyamide or polyphenylene sulfide.

[0041] The invention also relates to a rotating electrical machine comprising a rotor as described above and at least one stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Other characteristics, details and advantages of the invention will become more apparent from a reading of the following description on the one hand and with reference to the examples of embodiments illustrated by way of non-limiting indications on the other hand, in which:

[0043] Figure 1 A rotor of a rotating electrical machine according to the present invention is schematically shown, the rotor comprising a rotor body, a ring and bonded magnets, the bonded magnets having been injection-molded between the rotor body and the ring.

[0044] Figure 2 Schematically and independently depicted Figure 1 of the rotor body.

[0045] Figure 3 Schematically depicts an injection mold in which a Figure 1 The rotor body, rings and injection molded bonded magnets. DETAILED DESCRIPTION

[0046] The features, variants and various embodiments of the invention can be combined with each other in various combinations, as long as they are not mutually incompatible or exclusive. In particular, variants of the invention can be envisaged which only include a selection of the features described below, without regard to the other features described, if such a selection of features is sufficient to confer a technical advantage and / or to distinguish the invention from the prior art.

[0047] In the figures, elements common to several figures retain the same reference numerals.

[0048] In the following detailed description, the terms "longitudinal", "lateral" and "vertical" explain the orientation of the rotor for the rotating electrical machine according to the invention, these terms referring to the reference systems L, V, T shown in the figures.

[0049] therefore, Figures 1 to 3 A rotor 1 according to the invention is schematically depicted. The rotor 1 is intended to be integrated in a rotating electrical machine, such as a radial flux electrical machine also comprising at least one stator, to be fitted in a hybrid or electric vehicle, such as a car, truck, bicycle or an object that moves using its own drive system, such as a drone. Such a vehicle may also include an autonomous driving system.

[0050] The rotating electrical machine is capable of operating in alternator mode, in particular to supply electrical power to the battery and the vehicle's onboard electrical system, and in motor mode, not only to start the vehicle's internal combustion engine, but also to contribute to providing traction to the vehicle alone or in combination with the internal combustion engine.

[0051] The power of the electric motor 10 may be between 4 kW and 50 kW. Alternatively, the electric motor 10 may be mounted on an axle of a motor vehicle, in particular on the rear axle. In the example considered, the electric motor advantageously has an operating voltage of less than 60 volts, and preferably 48 volts. Typically, the torque provided by the electric motor is between 30 N.m and 150 N.m. Alternatively, the electric motor may have an operating voltage greater than 60 V, in fact greater than 80 V or greater than 100 V, in particular 300 V or more. In the case of operation at high voltage, the electric motor will typically have an operating voltage between 400 and 800 V, a power of up to 350 kW, and will provide a torque of up to 400 N.m.

[0052] The rotor 1 includes a rotor body 2, magnetic elements in the form of bonded magnets 4, and a ring 6. These constituent elements of the rotor 1 are arranged in this order around a rotation axis X of the rotor 1.

[0053] The rotor body 2 is arranged around a drive shaft element 8 which is located at Figure 1 . The rotor body 2 is a metal element, for example made of steel. The rotor body 2 is composed of a first annular portion 10, a second annular portion 12 and branches 14 extending radially between the first portion 10 and the second portion 12. The first portion 10 surrounds the drive shaft element 8, while the second portion 12, which has a larger diameter than the first portion 10, is arranged in contact with the bonded magnet 4. Between the first portion 10 and the second portion 12, the branches 14 extend in a star-shaped form; it will be understood that between these branches, the rotor body 1 has no material. The branches 14 are arranged at regular intervals between the first portion 10 and the second portion 12. In this case, the rotor body 2 includes eight branches 14, but rotor bodies 2 with different numbers of branches 14 may be envisaged without departing from the scope of the present invention.

[0054] The branch 14 extends over the entire height of the rotor 1 , measured along the axis of rotation X of the rotor 1 . In other words, the branch 14 extends from a first axial peripheral edge 16 of the rotor body 2 to a second axial peripheral edge 18 thereof, these axial peripheral edges 16 , 18 being opposite to each other in a direction parallel to the axis of rotation X of the rotor 1 .

[0055] The rotor body 2 has notches 20, Figure 2 As can be seen in FIG. 1 , the notch 20 is formed in the second portion 12 of the rotor body 2. The notch 20 is more specifically formed in a contact surface 22 of the second portion 12 of the rotor body 2, the contact surface 22 being intended to face the bonded magnet 4 and to be in contact with the bonded magnet 4.

[0056] The notch 20 extends from the contact surface 22 in the direction of the rotation axis X of the rotor 1. Figure 2 It is particularly visible in Figure 2 2. The rotor body 2 itself is shown in FIG. 2. The notches 20 do not pass directly through the second portion 12. The notches 20 include a first notch 20A extending axially, i.e. parallel to the axis of rotation X of the rotor 1, and a second notch 20B extending radially around the second portion 12, i.e. along the circumference of the rotor body 2. It will be appreciated that the first notch 20A and the second notch 20B are perpendicular to each other. The grid of notches 20 thus formed in the rotor body 2 allows for optimal coverage, but different arrangements of the notches 20 may be envisaged without departing from the scope of the invention.

[0057] The rotor body 2 radially delimits the rotor 1 just near the axis of rotation X of the rotor 1 , whereas the ring 6 radially delimits the portion of the rotor 1 furthest from the axis of rotation X. In other words, the rotor body 2 constitutes the inner radial end of the rotor 1 near the axis of rotation X, and the ring 6 constitutes the opposite outer radial end of the rotor 1 at a distance from the axis of rotation X.

[0058] The ring 6 is a non-magnetic annular element, for example made of stainless steel or carbon. The ring 6 comprises an outer surface 24 oriented toward the outside of the rotor 1 and an inner surface 26 diametrically opposite the outer surface 24 and facing the bonded magnets 4 and the rotor body 2 .

[0059] The ring 6 comprises recesses 28 formed at least on its inner surface 26. These recesses 28 are in this case separated from one another in the circumferential direction; in other words, they are not continuous along the ring 6. Figure 3As can be seen in the diagram of the embodiment of the present invention, the notches 28 are through-notches, in other words, they extend from the inner surface 26 of the ring to its outer surface 24. In an alternative embodiment not shown here, the notches 28 could extend radially over the entire circumference of the inner surface 26, it being understood that the notches 28 are not through-notches, in other words, they would extend only partially through the thickness of the ring.

[0060] If you can Figure 3 As seen in Figure 3 2 is a cross-sectional view showing both the score 20 on the rotor body 2 and the notch 28 on the ring 6, the second score 20B and the notch 28 being arranged at different heights in a direction parallel to the rotation axis X of the rotor 1. In other words, a given second score 20B on the rotor body 2 is not arranged to face a given notch 28 on the ring 6.

[0061] from Figure 1 and Figure 3 As can be seen in Figure 1 , the ring 6 has at least one collar 30. The collar 30 extends the annular body of the ring 6 in the direction of the axis of rotation X of the rotor 1. The collar 30 is arranged around a periphery 32 of the ring 6. This periphery 32 corresponds to an edge which delimits the ring 6 relative to a direction parallel to the axis of rotation X of the rotor 1. Thus, for each of the peripheries 32 delimiting the ring 6, in other words, on the first axial peripheral edge 16 of the rotor 1 and on its second axial peripheral edge 18, there is a collar 30.

[0062] As especially Figure 1 As can be seen in the drawings, the collar 30 is in this case castellated, i.e. it extends partially along the periphery 32. In this case, the collar 30 is divided into three parts distributed at regular intervals around the periphery 32. However, embodiments in which the collar 30 is continuous around the periphery 32 can be envisaged without departing from the scope of the present invention.

[0063] The collar 30 partially covers the bonded magnet 4. The bonded magnet 4 has a generally annular shape. It extends radially between the contact surface 22 of the second portion 12 of the rotor body 2 and the inner surface 26 of the ring 6, and it extends between a first axial end edge 34 and a second axial end edge 36 in a direction parallel to the rotation axis X of the rotor 1. Between the first axial end edge 34 and the second axial end edge 36, the bonded magnet 4 includes a central area 38. One of the collars 30 more specifically covers a portion of the first axial end edge 34, and the other of the collars 30 covers a portion of the second axial end edge 36. Therefore, it should be understood that at the collar 30, the height of the bonded magnet 4 measured in a direction parallel to the rotation axis X of the rotor 1 is less than the height of the bonded magnet 4 measured near the rotor body 2.

[0064] Furthermore, due to the collar 30 , the radial dimension of the first axial end edge 34 and / or the dimension of the second axial end edge 36 of the bonded magnet 4 measured in a plane facing the collar 30 perpendicular to the rotation axis X of the rotor 1 is smaller than the dimension of the central region 38 measured in the perpendicular plane.

[0065] As described above, the collar 30 only partially covers the bonded magnet 4. Therefore, the bonded magnet 4 is at least partially exposed in the rotor 1. In other words, except for the collar 30, the first axial end edge 34 of the bonded magnet 4 forms the first axial outer peripheral edge 14 of the rotor 1, and the second axial end edge 36 of the bonded magnet 4 forms the second axial outer peripheral edge 16 of the rotor 1.

[0066] As especially in Figure 3 As can be seen in the figure, the bonded magnet 4 has tabs 40. The tabs 40 correspond to individual increases in the radial dimensions of the bonded magnet 4 measured in a plane perpendicular to the axis of rotation X of the rotor 1. These tabs 40 extend radially from the central region 38 of the bonded magnet 4 in the direction of the rotor body 2 and the ring 6. The tabs 40 are more specifically positioned in the notches 20 on the rotor body 2 and the notches 28 on the ring 6. This positioning of the tabs 40 results from the injection molding of the bonded magnet 4 in the annular chamber between the rotor body 2 and the ring 6 during the obtaining method, which will now be described in detail.

[0067] The method for obtaining a rotor 1 according to the invention results in the manufacture of a rotor 1 as described above. The method of obtaining requires the use of an injection mold 42 of substantially cylindrical shape with a circular base. The injection mold 42 comprises an annular cavity radially delimited by a center pin 46 and an annular rim 48. The cavity is axially delimited by a bottom wall 50 and a cover 44. A coil 52 is arranged around the cavity, for example within the annular rim 48, as Figure 3 shown.

[0068] The method of obtaining starts with the manufacturing steps of the rotor body 2 and the ring 6. The rotor body 2 is made of steel, for example, while the ring 6 is made of stainless steel. The rotor body 2 and the ring 6 are each manufactured so that they have their respective notches 20 and recesses 28.

[0069] The method of obtaining comprises the step of positioning the rotor body 2 in the injection mold 42. More specifically, the rotor body 2 is placed against the bottom wall 50 and around a center pin 46 of the injection mold 42, the diameter of the center pin 46 being substantially the same as the diameter of the above-mentioned drive shaft element 8. Thus, the first portion 10 of the rotor body 2 is in contact with the center pin 46.

[0070] During the placement step, the ring 6 is again arranged in the cavity of the injection mold 42, in contact with its bottom wall 50 and its annular edge 48. More specifically, the outer surface 24 of the ring 6 is placed in contact with the annular edge 48. The method continues with a closing step, in which the injection mold 42 is closed by a cover 44, which defines the radial ends of the rotor 1. The cover 44 is placed on the rotor body 2 and on the ring 6. It will be understood from the above that the rotor body 2 and the ring 6 are arranged at a certain radial distance from each other inside the injection mold 42, so that an annular chamber is formed between them. According to the present invention, during the injection molding step, the bonded magnet 4 is injection molded inside this annular chamber between the rotor body 2 and the ring 6.

[0071] The material constituting the bonded magnet 4, in this case a rare earth alloy and a non-magnetic polymer, is thus injected into the injection mold 42 using an injection nozzle 54. The material constituting the bonded magnet 4 is deposited against the bottom wall 50 of the cavity of the injection mold 42. It fills the annular chamber together with the score 20 on the rotor body 2 and the notch 28 on the ring 6. The material constituting the bonded magnet 4 is injected into the cavity of the injection mold 42 up to the first axial peripheral edge 16 of the rotor 1 and, facing the collar 30, up to the periphery 32 of the ring 6.

[0072] Once the bonded magnet 4 is injection molded between the rotor body 2 and the ring 6, the obtaining method includes a pre-magnetization step during which power is supplied to the coil 52 arranged in the annular edge 48 in order to orient the magnetic charge of the bonded magnet 4. When the magnetic charge of the bonded magnet 4 is fixed, that is, once the material constituting the bonded magnet 4 has polymerized, the rotor body 2, the bonded magnet 4 and the ring 6 form a one-piece assembly.

[0073] The rotor 1 thus formed can then be removed from the injection mold 42 and demagnetized for transportation.

[0074] The method of obtaining then comprises a step of assembling the rotor 1 to the drive shaft element 8, during which this drive shaft element 8 is inserted into the first part 10 of the rotor body 2. The method of obtaining can continue with a magnetization step which makes it possible to return magnetic charges to the bonded magnets 4 according to the orientation determined during the previous pre-magnetization step. The magnetization step is made easier by the presence of indexing means (in this case holes 56) which provide the operator manufacturing the rotor 1 with information about the orientation to be observed defined during the pre-magnetization step. The rotor 1 can then be combined with a stator to form a rotating electrical machine.

[0075] The invention thus proposes a method for obtaining a rotor which is simplified in terms of the number of operations and which moreover facilitates the management of dimensional tolerances between the magnetic elements and the other components of the rotor.

[0076] However, the invention is not limited to the devices and configurations described and shown here, but also extends to all equivalent devices and configurations and any technically operable combination of these devices.

Claims

1. A method for obtaining a rotor (1) for a rotating electrical machine, the rotor comprising a rotor body (2), a magnetic element and a ring (6), the method comprising the following steps: Positioning the rotor body (2) inside the injection mold (42); placing the ring (6) around the rotor body (2) to form an annular chamber; A magnetic element in the form of a bonded magnet (4) is injection molded in the annular chamber.

2. The method according to claim 1, wherein the rotor body (2) includes a notch (20, 20A, 20B), and a portion of the bonded magnet (4) is inserted into the notch (20, 20A, 20B) on the rotor body (2) during the injection molding step.

3. The method according to any of the preceding claims, wherein the ring (6) comprises a recess (28), a portion of the bonded magnet (4) being inserted into the recess (28) on the ring (6) during the injection molding step.

4. The method according to any of the preceding claims comprises a step of pre-magnetizing the bonded magnet (4) within the injection mold (42), the pre-magnetizing step involving a plurality of coils (52) arranged in the injection mold (42) around the area where the ring (6) is placed.

5. The method according to any of the preceding claims, comprising the step of magnetizing the bonded magnet (4) outside the injection mold (42).

6. A rotor (1) of a rotating electrical machine, which can be manufactured according to the method described in any one of the preceding claims, the rotor having a rotation axis (X) and comprising a rotor body (2) and a ring (6) arranged around the rotor body (2) to form an annular chamber, and a bonded magnet (4) arranged in the annular chamber.

7. A rotor (1) according to claim 6, wherein the bonded magnet (4) comprises a lug (40) which extends inside the rotor body (2) and / or the ring (6) in a plane perpendicular to the axis of rotation (X) of the rotor (1).

8. The rotor (1) according to claim 7, wherein the tabs (40) of the bonded magnets (4) extend within the notches (20, 20A, 20B) on the rotor body (2).

9. The rotor (1) according to claim 7 or 8, wherein the tabs (40) of the bonded magnets (4) extend inside the recesses (28) on the ring (6).

10. A rotor (1) according to any one of claims 6 to 9, wherein the ring (6) comprises at least one collar, preferably toothed, partially covering the bonded magnets (4).

11. The rotor (1) according to any one of claims 6 to 10, wherein the bonded magnet (4) has axial end edges (34, 36) which lead to an axial peripheral edge (16, 18) of the rotor (1).

12. The rotor (1) according to any one of claims 6 to 11, wherein the bonded magnet (4) is made of ferrite or rare earth alloy and a non-magnetic binder material.

13. A rotating electrical machine comprising at least a rotor (1) according to any one of claims 6 to 12 and a stator.

Images