Synchronous electric machine with fixed clawed inductor

Abstract

One aspect of the invention relates to a synchronous electric machine (M1, M1', M1'', M1''', M2, M2', M20, M21, M20') comprising: - a first clawed stator inductor (1, 1', 4, 4') comprising a clawed ferromagnetic body (11, 41) comprising a number Pe of poles; - a first stator armature (2, 2', 2u, 5, 5', 5u) comprising a number Pa of poles different from the number Pe; - a ferromagnetic rotor (3, 6, 6') comprising: - an axis of rotation (X); - a first set of ferromagnetic parts (30, 30u, 60, 60u) comprising a number Ns of parts distributed regularly around the axis of rotation (X), wherein the number Ns is equal to the sum of or the difference between Pa / 2 and Pe / 2, the set of ferromagnetic parts (30, 30u, 60, 60u) being located between the first clawed stator inductor (1, 1', 4, 4') and the first stator armature.

Description

DESCRIPTION TITLE: Synchronous electric machine with fixed claw inductor TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of synchronous machines.

[0002] The present invention relates to a synchronous machine with armature and stator inductor. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Like any electric motor, a synchronous machine comprises a rotor and a stator; primarily, the rotor forms the field winding and the stator the armature. In the prior art, two methods are known for constructing a synchronous electric machine field winding: wound and magnetic. A wound field winding can offer an advantage. Indeed, a machine with a wound iron core can produce a higher magnetic induction than a magnetic field winding, which is also more expensive and thermally limited by its characteristics compared to a coil. Thus, for the same volume, a synchronous electric machine with a magnetic field winding will be more expensive, more thermally limited, and less efficient (torque), particularly at high rotational speeds, compared to an electric machine with a wound field winding.

[0004] It is also known primarily for two large families of air gaps in electrical machines.

[0005] A first family of synchronous electric machines has a radial air gap, in which the volume of air gap between a stator comprising coils forming the armature and the rotor forming an inductor (with magnet or wound) is cylindrical in shape surrounding the axis of rotation of the rotor.

[0006] A second family of synchronous electric machines has an axial air gap, the volume of which between a stator comprising coils forming the armature and the rotor forming the inductor (with magnet or wound) is in the shape of a disk perpendicular to the axis of rotation of the rotor.

[0007] The flux is primarily radial, called radial field in a radial air-gap machine, and primarily axial, called axial field in an axial air-gap machine, but it is also known in claw-rotor synchronous machines, of which the Flux comprises radial and axial components (whether radial or axial air gap). These claw-rotor machines have flux loops not contained in a plane. In other words, each loop is three-dimensional, called a warped curve, as opposed to a plane curve. For example, there are alternators or starter-alternators comprising a rotor field winding with a field coil and two pole pieces with claws. The two pole pieces are joined together to enclose the coil by means of the claws. The stator armature comprises coils wound in slots of several notched laminations. The armature coils convert the change in flux when the rotor field winding rotates into induced voltage, thus generating electric current.

[0008] Having a coil and two pole pieces with interlocking claws offers the advantage of simplifying rotor manufacturing, thus reducing cost and minimizing losses since the entire coil is utilized. However, as with magnet-type field rotors, the claws are subject to elastic deformation due to centrifugal force, necessitating a sufficiently large air gap, determined by the manufacturing tolerances of the armature's internal diameter and the claws' external diameter. The larger the air gap, the lower the performance of the synchronous electric machine. Furthermore, the wound field rotor requires brushes and two slip rings to energize the field rotor coil.However, as explained above, the advantage of varying the inductive flux allows either for a higher force and therefore higher torque (at low speed) or, when the inductive current is reduced, allows for lower magnetic losses at high speed for the same size of the electrical machine.

[0009] Therefore, there is a need for a synchronous electric machine architecture that has both the advantage of a wound inductor while having fewer disadvantages than a claw-rotor electric machine. SUMMARY OF THE INVENTION

[0010] The invention offers a solution to the problems mentioned above, by having a stator claw inductor and a stator armature.

[0011] One aspect of the invention relates to a synchronous electrical machine comprising: a first claw-type stator inductor comprising a claw-type ferromagnetic body comprising a number Pe of poles and an inductor coil wound in the ferromagnetic body, a first stator armature comprising a number Pa of poles different from the number Pe, a ferromagnetic rotor comprising: an axis of rotation (X) a first set of ferromagnetic parts comprising a number Ns of parts regularly distributed around the axis of rotation, the number Ns is equal to the sum of or the difference between Pa / 2 and Pe / 2, the set of ferromagnetic parts being located between the first claw-type stator inductor and the first stator armature.

[0012] Thanks to the invention, the synchronous electric machine has a wound stator claw inductor that combines several advantages: The advantage of the coil is that it allows for a higher inductance than magnets; The advantage of being free of rings and brushes; The advantage of being able to reduce the total air gap between the claws and the rotor since the rotor only includes ferromagnetic parts (without claw shape). The advantage of being without a bun and therefore using the entire coil and thus ampere-turns of the inductor coil for each pair of poles, and thus producing a magnetic field with significantly less Joule loss than with a bun to produce the magnetic flux.

[0013] In other words, the synchronous electric machine according to the invention has the advantages of a synchronous claw machine without its disadvantages.

[0014] The number Ns of ferromagnetic parts in the rotor (which is either the sum or the difference with the number of poles Pa of the armature and the number of poles Pe of the field winding (Pa being different from Pe)) allows the rotor to modulate the flux between the armature stator and the stator claw inductor to either rotate the rotor in motor mode or generate current in the stator armature in generator mode.

[0015] In addition to the characteristics mentioned in the preceding paragraph, the synchronous electric machine according to one aspect of the invention may have one or more complementary characteristics from those in the following paragraphs, considered individually or according to all technically possible combinations.

[0016] In one embodiment, the ferromagnetic rotor is located axially between the first stator armature and the first stator claw field winding. Thus, in this case, the air gap is axial. The magnetic flux produced by the stator armature and the stator field winding is modulated by the assembly of ferromagnetic components and passes axially through the air gap.

[0017] According to one example of this embodiment, the electrical machine comprises a second inductor of identical shape to the first claw inductor and having an external diameter smaller than the internal diameter of the first claw inductor, wherein the first claw inductor surrounds the second stator claw inductor. In particular, each internal claw of the first inductor is radially contiguous with an external claw of the second inductor, and each external claw of the first inductor is radially contiguous with an internal claw of the second inductor.

[0018] According to an embodiment that is a variant of the previous embodiment, the first set of ferromagnetic parts is located concentrically between the first stator armature and the first stator claw field winding. Thus, in this case, the air gap is radial. The magnetic flux produced by the stator armature and the stator field winding is modulated by the set of ferromagnetic parts and passes axially and radially through the air gap.

[0019] According to one example of this embodiment, the first claw-type stator inductor surrounds the first set of ferromagnetic parts of the ferromagnetic rotor surrounding the stator armature.

[0020] According to a variant of this example of this embodiment, the first stator armature surrounds the first set of ferromagnetic parts of the ferromagnetic rotor surrounding the claw stator inductor.

[0021] In one embodiment, the first stator armature is a claw armature. This allows the entire coil to be used, thus resulting in better efficiency.

[0022] According to one example, the claw stator armature comprises a first block including a first pole base and a second pole base and a coil between the first and second pole bases.

[0023] According to one embodiment, the machine further comprises: a second inductor of identical shape to the first inductor, a second stator armature comprising air gap parts, of identical shape to the first claw-type stator armature, and in that the rotor further comprises a second set of ferromagnetic parts identical to the first set of ferromagnetic parts forming a first air gap with the second inductor and being opposite the air gap parts of the second stator armature forming an air gap between them.

[0024] By identical shape, we mean the geometric shape but not the dimensions, so a first inductor can be larger in size than the second inductor.

[0025] According to one implementation of this example of this embodiment, the machine further comprises: a third inductor of identical shape to the first inductor, a third claw-type stator armature of identical shape to the first block comprising air gap parts and in that the rotor further comprises a third set of ferromagnetic parts identical to the first set of ferromagnetic parts, forming an air gap with the third inductor and being opposite the air gap parts of the third stator armature forming an air gap between them.

[0026] Such a machine has the advantage of being claw-type and having an armature that can be supplied by, or output, a three-phase alternating voltage. Indeed, each armature can thus constitute a phase.

[0027] According to one example of this embodiment, the machine further comprises: a second claw-type stator inductor of identical shape to the first claw-type stator inductor and a second claw-type stator armature of identical shape to the first claw-type stator armature; a second rotor mechanically decoupled from the first rotor, comprising a set of ferromagnetic components located between the second claw-type stator inductor and the second claw-type stator armature, in which either the two claw-type stator armatures or the two claw-type inductors are integral, sharing a common base. In the case of an axial air gap, the two rotors are coaxial, and in the case of a radial air gap, the two rotors are parallel to each other with their axes spaced apart.

[0028] According to a variant of this embodiment, the first induced element has a salient pole. For example, it comprises a winding consisting of different coils forming a multi-phase system.

[0029] According to an embodiment that is a variant of the preceding embodiment, the armature comprises teeth having first air gap walls and second air gap walls opposite the first air gap walls by means of a central wall, an armature winding comprising coils each wound in a corresponding tooth around the central wall between the first and second air gap walls, the synchronous electric machine further comprising: a second field winding of identical form to the first field winding, and in that the rotor further comprises a second set of ferromagnetic parts identical to the first set of ferromagnetic parts, forming an air gap with the second field winding and being opposite the second air gap walls of the stator armature, forming an axial air gap between them.

[0030] According to one embodiment, the machine further comprises a second and third inductor identical to the first inductor, a second and third claw stator armature identical to the first armature comprising air gap portions and in that the rotor further comprises a second and third set of ferromagnetic parts identical to the first set of ferromagnetic parts, each forming respectively an air gap with the second and third inductor and being opposite the air gap portions respectively of the second and third stator armature forming between them an air gap.

[0031] In one embodiment, the ferromagnetic claw body of the claw inductor comprises a base and claws, wherein each claw includes an intermediate portion extending perpendicularly from the base and an air gap portion extending from the intermediate portion parallel to the base. The inductor coil is wound in a zone formed between the base, the intermediate portion, and the air gap portion. The claw inductor further comprises inter-claw-base magnets for each claw, each located between the base and a free end of the corresponding intermediate portion of the claw. This increases the magnetic saturation level of the claw, resulting in a higher inductor current before saturation and thus the potential for greater torque. In other words, a claw without a magnet will saturate magnetically more quickly than the same claw with a magnet.

[0032] According to one embodiment, the inductor comprises inter-claw magnets located in each space formed between two adjacent claws of different polarities.

[0033] According to one embodiment, the first ferromagnetic body of the claw-type stator inductor comprises a first pole base and a second pole base, and the inductor coil is located between the first and second pole bases.

[0034] In one embodiment, the electrical machine includes a coolant circuit in which the inductor is immersed, in particular in a dielectric liquid. This allows it to be cooled much more easily than a rotating inductor structure, indeed this cooling technique is direct, thus offering higher performance than a structure that is not or less cooled.

[0035] According to one embodiment, the ferromagnetic claw body comprises a material formed from compressed powder.

[0036] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0037] The figures are presented for illustrative purposes only and are in no way limiting to the invention.

[0038] [Fig. 1 A] shows a schematic representation of a synchronous electrical machine according to a first example of a first embodiment.

[0039] [Fig. 1 B] shows a schematic representation of a synchronous electrical machine according to a second example of a first embodiment.

[0040] [Fig. 2] shows a schematic representation of a radial section of the synchronous electric machine according to the first example of a first embodiment.

[0041] [Fig. 3] shows an exploded schematic representation of an example of a claw stator inductor of the synchronous electric machine according to the first example of a first embodiment.

[0042] [Fig. 4] shows a schematic representation according to a partial three-dimensional view, of another example of the claw stator inductor of the synchronous electric machine according to the first example of a first embodiment.

[0043] [Fig. 5] shows a schematic representation of a radial section of the synchronous electric machine according to the second example of a first embodiment.

[0044] [Fig. 6] shows a schematic representation in a three-dimensional view, of an example of a claw stator inductor of the synchronous electric machine according to the first example of a first embodiment.

[0045] [Fig. 7] shows a schematic representation along a radial section of a synchronous electrical machine according to a third example of the first embodiment.

[0046] [Fig. 8] shows a schematic representation along a radial section of a synchronous electrical machine according to a fourth example of the first embodiment.

[0047] [Fig. 9] shows a schematic representation of a synchronous electrical machine section according to a first example of a second embodiment.

[0048] [Fig. 10A] shows an exploded schematic representation of a first example of a claw stator inductor of the synchronous electric machine according to the first example of the second embodiment.

[0049] [Fig. 10B] shows a schematic representation of a clawed ferromagnetic body and inter-claw magnets of a second example of a clawed stator inductor of the synchronous electric machine according to the first example of the second embodiment.

[0050] [Fig. 10C] shows a schematic representation of a ferromagnetic claw body and inter-claw-base magnets of a third example of a claw stator inductor of the synchronous electric machine according to the first example of the second embodiment.

[0051] [Fig. 10D] shows a schematic representation of a ferromagnetic claw body, inter-claw-base magnets and inter-claw magnets of a fourth example of a stator claw inductor of the synchronous electric machine according to the first example of the second embodiment.

[0052] [Fig. 1 1 ] shows a schematic representation of an example of a stator armature of the synchronous electric machine according to the first example of the second embodiment.

[0053] [Fig. 12] shows a schematic representation according to a three-dimensional view of an example of a ferromagnetic rotor of the synchronous electric machine according to the first example of the second embodiment.

[0054] [Fig. 13A] shows a schematic representation of a synchronous electrical machine according to a second example of the second embodiment.

[0055] [Fig. 13B] shows a schematic representation of a synchronous electrical machine according to a third example of the second embodiment.

[0056] [Fig. 13C] shows a schematic representation of a cross-section of a tooth of an armature of the synchronous electric machine according to the third example of the second embodiment.

[0057] [Fig. 14] shows a schematic representation of a radial section of a synchronous electric machine according to a fourth example of the second embodiment.

[0058] [Fig. 15] shows a schematic representation of a radial section of a synchronous electric machine according to a fifth example of the second embodiment.

[0059] [Fig. 16] shows a schematic representation of a synchronous electric machine section according to a sixth example of the second embodiment.

[0060] [Fig. 17] shows a schematic representation of a double claw inductor of a synchronous electric machine according to the sixth example of the second embodiment. DETAILED DESCRIPTION

[0061] The figures are presented for illustrative purposes only and are in no way limiting to the invention.

[0062] By rotor, we mean an element that rotates on itself around its own axis of rotation.

[0063] A stator element is understood to be a static element which is therefore immobile relative to the axis of rotation of the rotor.

[0064] The invention relates to a synchronous electrical machine M1, M2, of which different examples of two different embodiments will be described below.

[0065] Figures 1A to Figure 8 show a schematic representation of the synchronous electric machine M1 or part thereof according to examples of the first embodiment and Figures 9 to Figure 17 show a schematic representation of the synchronous electric machine M2 or part thereof according to examples of the second embodiment.

[0066] In both embodiments, the synchronous electric machine M1, M2 comprises at least: a first claw-type stator inductor 1, 4 comprising a claw-type ferromagnetic body 1, 1, 41 comprising a number Pe of poles and an inductor coil 10, 40 wound in the ferromagnetic body 1, 1, 41; a first stator armature 2, 5 comprising a number Pa of poles different from the number Pe; a ferromagnetic rotor 3, 6 comprising: a rotation shaft; a first set of ferromagnetic parts 30, 60 comprising a number Ns of parts regularly distributed around the rotation shaft, the number Ns being equal to the sum of or the difference between Pa / 2 and Pe / 2, the set of ferromagnetic parts 30, 60 being located between the first claw-type stator inductor 1, 4 and the first stator armature. 2, 5.

[0067] In both embodiments, the electrical machine M1, M2 comprises at least two air gaps, a first air gap between the first stator inductor and claws 1, 4 and the ferromagnetic rotor 3, 6 and a second air gap between the first stator armature 2, 5 and the ferromagnetic rotor 3, 6.

[0068] In the first embodiment, the air gaps are radial and in the second embodiment the air gaps are axial. In other words, in the first embodiment, the first set of ferromagnetic parts 30 is located concentrically between the first stator armature 2 and the stator claw inductor 1, while in the second embodiment, the first set of ferromagnetic parts 60 is located axially between the first stator armature 5 and the stator claw inductor 4.

[0069] In the various examples of the two embodiments, the ferromagnetic claw body of the claw inductor comprises a base and claws, in which each claw comprises an intermediate part extending from the base perpendicularly to the base and an air gap part extending from the intermediate part parallel to the base, the inductor coil wound in an area formed between the base, the intermediate part and the air gap part.

[0070] [Fig. 1 A] shows a schematic representation of an axial section of a first synchronous machine M1 according to a first example of a first embodiment.

[0071] In this first example, the stator armature 2 surrounds the ferromagnetic rotor 3 which surrounds the claw-type stator inductor 1.

[0072] [Fig. 2] shows a schematic representation of a radial section of the synchronous electric machine M1 according to the first example of a first embodiment.

[0073] In this example of the first embodiment, the stator armature 2 is an armature comprising a winding 20 wound in a lamination pack 21. The winding 20 comprises three coils 20u, 20v, 20w, each forming one phase of a three-phase system. Of course, the winding can comprise more than three coils, for example five or six, forming, for instance, a double three-phase system.

[0074] The 20u, 20v, 20w coils are wound in notches of the 21 sheet metal pack. In this case, the winding is concentric, but could be according to another type of winding such as distributed for example corrugated or corrugated distributed.

[0075] In this example, the first stator induced 2 comprises a number Pa of poles, in this case 10, i.e. 5 pairs of poles = Pa / 2.

[0076] In this example, the rotor 3 has 8 ferromagnetic parts 30 and the claw inductor 1 of the machine has a corrugated inductor coil 10 in a ferromagnetic claw body 11 which has three claws per base (i.e. three north claws and three south claws) and.

[0077] [Fig. 3] shows a schematic representation of an exploded view of a claw-type stator inductor 1 of the synchronous electric machine M1 according to a second example of a first embodiment.

[0078] The clawed stator inductor 1 comprises, in this case, a ferromagnetic clawed body 11 comprising a first base including a first flange 115a and first claws 11a of one polarity, each extending axially from the flange 115a, and a second polar base including a second flange 115b and second claws 11b of the other polarity, each extending axially from the second flange 115b to the first flange 115a between two first claws 11a. For example, the first claws 11a have a south polarity (this depends on the direction of the current flowing in the inductor coil 10) and the second claws have a north polarity. The two flanges 115a and 115b have a crown shape, each comprising a core having an orifice in axial contact with each other.The claws 11a, 11b each comprise an intermediate portion 114a, 114b extending from the base 115a, 115b and an air gap portion 113a, 113b opposite the ferromagnetic rotor 3 (not shown here). The air gap portion 113a, 113b includes an external surface facing the ferromagnetic parts 30, together forming the radial (cylindrical) air gap. The external diameter of the claws 11a, 11b is therefore measured at this external surface of the air gap portion 113a, 113b. The inductor coil 10 is located axially within the ferromagnetic claw body 11 between the first and second pole pieces. The first and second polar base each comprise Pe / 2 claws, here in this case 6 claws, each forming a pole, so in this example the stator inductor with claws 1 comprises a number Pe of poles = 12, i.e. 6 pairs of poles.

[0079] In this example, the claw-type stator inductor 1 further includes inter-claw magnets 13 between the claws 11a, 11b of each pole base for to increase in a known manner the efficiency of the claw stator inductor 1. As the claw stator inductor 1 is stationary relative to the axis of rotation, the inter-claw magnets 13 do not experience centrifugal force and are therefore simpler to interpose than in prior art claw rotor inductors.

[0080] The claw-type stator inductor 1 further includes a fixed shaft 12 on which bearings can be mounted to support the ferromagnetic rotor 3.

[0081] In the case where the synchronous electric machine M1 includes the claw stator inductor of Figure 3 and the armature of Figure 2, the ferromagnetic rotor must therefore include a number Ns = 5 + 6 = 1 of 30 ferromagnetic parts.

[0082] Figure 4 shows another example of a claw-type stator inductor 1 comprising the fixed shaft 12, the inductor coil 10 wound in the ferromagnetic body 11 between the claws 11a, 11b, of each polarity, the ferromagnetic body 11 here comprising a plurality of lamination bundles 110, of which only two are shown. Each lamination bundle forms a first claw 11a and a second claw 11b (a north polarity and a south polarity) which are opposite each other. Each sheet of a pack of sheets 110 comprises an axial base 1 15 surrounding the fixed shaft 12, a first claw portion and a second claw portion each forming a part respectively of the first and second claws 1 1 a, 1 1 b, each extending from a corresponding (opposite) end of the base 1 15.Each claw 11a, 11b comprises an intermediate portion 114a, 114b extending from the end of the base 115 and an air gap portion 113a, 113b opposite the ferromagnetic rotor 3 (not shown here). The sheets of the sheet bundle are interlaced by being folded against each other to form each claw.

[0083] Thus the first sheet of a pack of sheets 1 10 comprises: a first part of air gap forming a portion of a first claw juxtaposed to another claw of another pack of sheets and a second part of air gap forming a portion of a second claw juxtaposed to the first part of the last sheet of the first claw of the pack of sheets.

[0084] In this example, optionally, each air gap portion 1 13 of each claw includes a projection towards the rotor 3 (in this example outwards) but It could also be flat. Ferromagnetic parts can then have an internal groove partially surrounding these protrusions.

[0085] Figure 1B and Figure 5 show a schematic representation of an axial and radial section respectively of a first MT synchronous machine according to a second example of a first embodiment, in which the claw-type stator inductor 1' surrounds the ferromagnetic rotor 3 surrounding the stator armature 2'.

[0086] The ferromagnetic rotor 3 can be identical to that of the first example.

[0087] Figure 6 shows a schematic representation according to a three-dimensional view of an example of the claw stator inductor 1' of the MT synchronous electric machine according to the second example of a first embodiment.

[0088] In this second example, each claw 11a, 11b, comprises an air gap portion 113' including an internal surface facing the ferromagnetic parts 30 of the rotor 3. The internal diameter of the stator inductor with claws 1' is measured between two internal surfaces of this air gap portion 113'. In this example, the stator ferromagnetic body 11 of the stator inductor with claws 1' comprises a yoke 11c and a first pole base comprising the first claws 11a of a first polarity, for example North, and a second pole base comprising the second claws 11b of an opposite polarity, in this example South. The first pole base is thus axially fitted against the other pole base, each having its base surrounded by the yoke 11c. Each first claw 1 1 a of the first polar base is located angularly between two second claws 1 1 b of the second polar base.

[0089] Of course, the ferromagnetic body 1 1 stator of the claw stator inductor 1' can include bundles of laminations as in the example of Figure 4 except that the air gap parts are inwards, i.e. includes an internal surface opposite the ferromagnetic parts 30 of the rotor 3.

[0090] In this example, the claw-type stator inductor 1' comprises eight poles, so the number Pe of poles is equal to 8.

[0091] In this example, the number Ns of ferromagnetic parts 30 is equal to 1 1, visible in figure 5.

[0092] The stator armature 2' in this example comprises a lamination pack 20 with slots open outwards. The winding 20 is thus wound in the outer slots and, as in the previous example, can comprise three coils. In this example, there are 42 slots, corresponding to 7 pole pairs, Pa / 2 = 7, Ns = 11, and Pe / 2 = 4.

[0093] In the two examples described above, the stator armature 2, 2' is a salient pole armature (formed by teeth between the slots each filled by one or more sections of the coil) but can also be claw-type.

[0094] [Fig. 7] schematically represents an axial section of a synchronous electric machine M1 according to a third example of the first embodiment in which the armature is a stator armature with claws 2u. The field winding of the synchronous electric machine M1 as well as its ferromagnetic rotor 3 according to this third example is identical to that of the first example.

[0095] The claw-type stator armature 2u is similar to the claw-type inductor of the second example in that it comprises in this example a single coil 20u' (single-phase) wound in an armature body 21u comprising a first pole base 21a and a second pole base 21b nested axially against each other such that each claw of the first pole base 21a is located angularly between two claws of the second pole base 21b. Each claw is represented either as a dashed line or has a dashed part to improve understanding. Each claw comprises an air gap portion 23 having an internal surface facing the air gap parts 30 of the rotor 3. The internal diameter of the clawed stator armature 2” is measured between the internal surfaces of the air gap parts 2. The two pole bases 21a, 21b each comprise a base portion axially joined to each other forming an external base 210.The first pole piece 21a and the second pole piece 21b can be identical and are simply fitted axially against each other, offset angularly by one claw. The coil 20u' is therefore located axially between the first and second pole pieces 21a, 21b, between the internal air gap 23 of each claw and the external base 210 of each pole piece surrounding the armature coil 20u'. Of course, the armature body 21u can also be formed from a stack of laminations, as in the example of the field winding in Figure 4. The armature body can also be formed from a single block with the claws bent towards each other.

[0096] According to another example, the ferromagnetic body of the claw-type stator armature 2u is identical to the claw-type stator inductor of the second example, that is to say, it includes a yoke connecting the first pole base 21 a comprising the claws of a first polarity, for example North, to the second pole base 21 b comprising the claws of an opposite polarity, in this example South.

[0097] According to another example of this first world of realization not shown, the inductor is the 2" claw stator armature of the third example and the claw stator armature is the 1" claw stator inductor (i.e. a variant of the second and third examples combined).

[0098] [Fig. 8] Schematic representation of a synchronous electric machine M1 '” according to a fourth example of the first embodiment identical to the third example of this first embodiment except that: the machine further comprises a second and third armature 2v, 2w identical to the first armature 2u, two other stator claw inductors 1v, 1w identical to the first stator claw inductor 1u of the third example, and that the ferromagnetic rotor 3 comprises two other sets of ferromagnetic parts 30v, 30w identical to the first set of ferromagnetic parts 30u.

[0099] Thus, the second and third armatures (2V, 2W) each comprise a first and second armature body (21V, 21W) identical to the first armature body (21U) of the third example, and respectively a second and third coil (20V', 20W') each mounted in the second and third armature bodies (21V, 21W). The first and second armature bodies (21V, 21W) have air gap sections opposite the second and third sets of ferromagnetic components (30V, 30W), respectively. This synchronous electric machine M1 allows for three armature coils (20U', 20V', 20W'), each of which can be powered in motor mode or output in alternator (alternating current generator) mode at a three-phase voltage.

[0100] The first, second, and third sets of ferromagnetic parts 30u, 30v, 30w, or the air gap sections of the first, second, and third claw-type stator armatures 2u, 2v, 2w, are angularly offset from each other according to the number of ferromagnetic parts, or respectively, of claws. According to another example, it is the claws of the first, second, third claw stator inductors 1 u, 1 v, 1 w that are angularly offset from the air gap parts of the first, second, third claw stator armature 2u, 2v, 2w relative to each other according to the number of ferromagnetic parts or respectively of claws.

[0101] According to another example not shown, the synchronous electric machine differs from the fourth example in that the claw-type stator inductor 1 comprises only the first ferromagnetic body 1 extending axially along the rotor 3 with a single inductor coil 10.

[0102] According to another example not shown, the synchronous electric machine differs from the fourth example in that the claw-tipped stator inductor 1 surrounds the rotor 3 which surrounds the three claw-tipped armatures 2u, 2v, 2w, (having the same shape as the three armatures of the fourth embodiment).

[0103] In the various examples of this first embodiment, the air gaps are radial between the rotor and the armature, and between the rotor and the field winding. A synchronous electric machine will now be described according to a second embodiment identical to the first example, except that the air gaps between the rotor and the armature, and between the rotor and the field winding, are axial. The various options and characteristics of the examples described previously can be applied to the first example when they do not concern the geometric shape of the armature, rotor, and field winding, which would result in an axial air gap.

[0104] [Fig. 9] shows a schematic representation of a section of a synchronous electrical machine M2 according to a first example of a second embodiment.

[0105] The synchronous electric machine M2 includes a first claw-type stator inductor 4 comprising a claw-type ferromagnetic body 41 having a number Pe of poles and an inductor coil 40 wound in the claw-type ferromagnetic body 41. Four different examples of claw-type stator inductors 4A, 4B, 4C, 4D will be described in figures 10A to 10D which can be the first claw-type stator inductor 4.

[0106] [Fig. 10A] shows a schematic representation in a three-dimensional view of an initial implementation of a 4A claw-type stator inductor exploded view of the synchronous electric machine M2 according to a first example of a second embodiment.

[0107] The inductor coil 40 is schematically represented by circles, suitable for placement within the ferromagnetic claw body 41. The ferromagnetic claw body 41 is shown transparently. The ferromagnetic claw body 41 comprises a ring-shaped base 415 (with a central opening to support a rotor shaft by means of a bearing) but could also be a solid disc. The ferromagnetic claw body 41 comprises external claws 41A extending from the outer perimeter of the base 415, having one polarity, for example, South, and internal claws 41B extending from the inner perimeter of the base 415, having the other polarity, in this example North (the polarity depends on the direction of the current flowing in the inductor coil 40). In this example, the number of external claws 41 A is equal to 6 and the number of internal claws 41 B is equal to 6, resulting in a number Pe of poles equal to 12 (the sum of the internal and external claws).Each external and internal claw 41A, 41B comprises an intermediate portion 414a, 414b extending radially from the base 415 towards the rotor 6 and an air gap portion 413a, 413b opposite the first set of ferromagnetic parts 60, together forming an axial air gap. The air gap portion 413a of an external claw 41A extends inwards from the intermediate portion 414a, in this case decreasing its width, while the air gap portion 413b of an internal claw 41B extends outwards from the intermediate portion 414b, in this case increasing its width.

[0108] [Fig. 1 OB] shows a schematic representation in three-dimensional view of a second implementation of a stator inductor with claws 4B of the synchronous electric machine M2 according to the first example of the second embodiment. The stator inductor with claws 4B according to this second implementation is identical to the first implementation except that it includes inter-claw magnets 43 located in each gap formed between two adjacent claws 41A, 41B of different polarities. In other words, each inter-claw magnet 43 is located between an air gap portion 413a of an outer claw 41A, and an air gap portion 413b of an outer claw 41B.

[0109] [Fig. 10C] shows a schematic representation in a three-dimensional view of a third implementation of a 4C claw-type stator inductor of the synchronous electric machine M2 according to the first example of the second mode of implementation. The stator inductor with claws 4C is identical to the first implementation except that it includes an inter-claw-base magnet 45 per claw. Each inter-claw-base magnet 45 is located between a free end of the air gap portion 413a, 413b of an external claw 41 A or internal claw 41 B, and the base 415.

[0110] [Fig. 1 OD] shows a schematic representation in three-dimensional view of a fourth embodiment of a 4D claw-type stator inductor of the synchronous electric machine M2 according to the first example of the second embodiment. The 4D claw-type stator inductor is identical to the first embodiment, except that it includes an inter-claw-base magnet 45 per claw and an inter-claw magnet 43 between each claw.

[0111] According to a particular feature of one of these implementations, the ferromagnetic claw body 1 1 41 comprises a material formed from compressed powder. Such powder with such magnets has the particularity of increasing the capacitance of the ferromagnetic body before saturation.

[0112] [Fig.1 1 ] shows a schematic representation according to a three-dimensional view of an example of a stator armature 5 of the synchronous electric machine M2.

[0113] In this first example, the stator armature 5 includes an armature body 51 with salient poles comprising a base 510 in the shape of a crown and a plurality of teeth 51 1 forming notches between them (here numbering 12 teeth and notches).

[0114] Each tooth 511 comprises a central wall 514 extending axially from the base 510 and an air gap wall 516 extending from the central wall 514 opposite the first set of ferromagnetic parts 60, together forming an axial air gap. The air gap wall 516 extends circumferentially on either side of the central wall 514, partially closing the slots axially. The armature body 51 can be formed from several concentric sheets wound within each other or from a single sheet wound in a spiral. The stator armature 5 in this example comprises a concentric winding 50, consisting of a plurality of coils 50u, 50v, 50w, in this case a three-phase winding comprising first coils 50u, second coils 50v, and third coils 50w, each coil being wound around a tooth 51 1 of the armature body 51. The stator armature 5 comprising a number Pa of poles different from the number Pe of poles.

[0115] Here the winding is therefore wound with a ratio of 0.5 notches per pole and per phase, i.e. a number of poles equal to 8.

[0116] [Fig. 12] shows a schematic representation of an example of the ferromagnetic rotor 6 of the synchronous electric machine M2 in a three-dimensional view. The ferromagnetic rotor 6 is, in this instance, internal and includes a rotating shaft 61 about its axis of rotation X (not visible in Figure 12, but visible in Figure 9). Of course, the rotor 6 could, in another example, be external.

[0117] The ferromagnetic rotor 6 comprises the first set of ferromagnetic parts 60 evenly distributed around the axis of rotation X. Each ferromagnetic part is mounted on a ring 62 fixed to the rotation shaft 61 of the rotor 6. The number Ns of ferromagnetic parts 60 is equal to the sum of, or the difference between, Pa / 2 and Pe / 2, here numbering 10, i.e., Pa / 2 + Pe / 2, but could also be numbered 2 (the difference). The set of ferromagnetic parts 60 is located axially between the first stator claw inductor 4 and the first stator armature 5.

[0118] [Fig. 13A] shows a schematic representation of a synchronous electrical machine M20 according to a second example of the second embodiment.

[0119] In this second example, the synchronous electric machine M20 is identical to that of the first example of this second embodiment except: that it also includes a second inductor 4' identical to the first inductor 4, in this case as one of the various examples shown in one of Figures 10A to 10D of the first example; that the rotor 6' also includes a second set of ferromagnetic parts 60' identical to the first set of ferromagnetic parts 60, forming an axial air gap with the second inductor 4'; and that it includes a second stator armature 5' identical to the first stator armature 5, in this case as the one shown in the figure 1 1 of the first example, opposite the second set of ferromagnetic parts 60' forming an axial air gap between them.

[0120] The second inductor 4' has its crown-shaped base 415 against the base 415 of the first inductor 4', with the air gap portions 413a, 413b of each internal and external claw 41b, 41a opposite the second set of ferromagnetic parts 60', together forming an axial air gap. The armature body 51 with salient poles of both inductors 4, 4' can be a single piece.

[0121] The coils of the second stator armature 5' can be coupled in parallel with the corresponding coils of the first stator armature 5.

[0122] The rotation shaft 61 of the rotor 6' passes through the second inductor 4' and the first inductor 4.

[0123] According to an example not shown, the second set of ferromagnetic parts 60' can be decoupled from the first set of ferromagnetic parts 60 and thus form a second rotor.

[0124] [Fig. 13B] shows a schematic representation of an electrical machine M21 according to a third example of the second embodiment.

[0125] In this third example, the synchronous electric machine M21 is identical to that of the second example of this second embodiment except: the stator armature is a 5” through flux stator armature, similar to the first stator armature 5 of the first example except that it is without a base and that each tooth 511 ' represented according to a section on figure 13C, includes a second air gap wall 516 opposite the second set of ferromagnetic parts 60' forming between them an axial air gap and that the second claw inductor 4' is axially opposite the first claw inductor 4.

[0126] Thus in this example the rotor 6' is identical to that of the second example.

[0127] Thus, each tooth 511' comprises a second air gap wall 516' opposed to the first air gap wall 516 via the central wall 514 of the through-flow stator armature 5”. The teeth 511' can be connected to each other, by a non-ferromagnetic part, for example by a resin. In other words, this stator armature 5” is without a yoke. Each coil of each tooth 51' of the stator armature 5” produces a flux that passes from the first to the second air gap wall 516. In other words, the flux passes from the first field winding 4 to the second field winding 4' through the ferromagnetic parts of the rotor and the armature 5'.

[0128] Thus the through-flux stator armature 5” is located axially between the first and second set of ferromagnetic parts 60, 60' of the rotor 6', which are located axially between the first and second claw inductor 4, 4'.

[0129] In these different examples, the stator armatures 5, 5' have salient poles but can be clawed as in the third example of the first embodiment (except that the armature has an axial air gap.

[0130] In both examples, having a rotor with two sets of ferromagnetic parts axially offset from each other reduces the axial force on the rotor. Indeed, in each case, the resultant of the axial force, represented by arrows F, exerted on the first set of ferromagnetic parts by the first armature and the first field winding, is in the opposite direction to the resultant of the axial force exerted on the second set of ferromagnetic parts by the second armature and the second field winding.

[0131] [Fig. 14] shows a schematic representation of a synchronous electric machine section M2' according to a fourth embodiment identical to the first embodiment of this second embodiment except that the stator armature 5u has claws. In this fourth embodiment, the stator armature 5u is similar to the claw-type stator field winding 4 except that it has a different number of claws. In this example, the synchronous electric machine M2' is single-phase.

[0132] Of course the M2' synchronous electric machine can be multi-phase, in which case it includes several armatures and inductors as well as several sets of ferromagnetic parts.

[0133] [Fig. 15] shows a schematic representation of a synchronous electric machine section M20' according to a fifth example of the second embodiment similar to the synchronous electric machine M2' but multiphase, in this case three-phase.

[0134] The M20' synchronous electric machine is therefore identical to the fourth example embodiment except that it comprises: a second and a third 5v, 5w claw-type stator armature identical to the first 5u claw-type stator armature of the fourth example of this embodiment, comprising respectively a second and third 50v, 50w coils each mounted in the second and third armature bodies 51v, 51w, a second and third 4v, 4w claw-type field winding identical to the first 4u claw-type stator armature of the fourth example of this embodiment, comprising respectively a second and third 40v, 40w field winding each mounted in the second and third armature bodies 41v, 41w, and in that the 6” rotor comprises a second and third set of 60v ferromagnetic parts,60w identical to the first set of ferromagnetic parts 60u of the fourth example of this embodiment, the sets of ferromagnetic parts 60u, 60v, 60w being mounted integrally with the rotor shaft 61.

[0135] In this case, the first and second 4u, 4v claw-type inductors are monobloc, and the second and third 5v, 5w claw-type stator armatures are also monobloc, meaning they share a common base. In these various examples, the different inductors and armatures are stacked axially one after the other, maintaining a rotor with two sets of ferromagnetic components offset axially from each other.

[0136] [Fig. 16] shows a schematic representation of a synchronous electric machine section M2” according to a sixth example of the second embodiment identical to the synchronous electric machine M2’ according to the first example except that it further comprises a second stator claw inductor 4” having an external diameter smaller than the internal diameter of the first claw inductor 4 and in that the first claw inductor 4 surrounds the second stator claw inductor 4”. Figure 17 shows an axial view of the first and second claw inductors 4”. In particular, each internal claw 41B of the first inductor 4 is radially contiguous with an external claw 41A of the second inductor 4”, and in that each external claw 41 A of the first inductor 4 is radially contiguous with an internal claw 41 B of the second inductor 4”.

[0137] A claw inductor can exhibit magnetic flux leakage, particularly when the inner diameter is much smaller than the outer diameter. The axial air gap solution presents geometric asymmetries between the inner claws 41B and the outer claws 41A. As can be seen in Figures 10A to 10D, the intermediate sections 414b are narrower (measured circumferentially) on the inner claws 41B, which are on the inner diameter side, than the intermediate sections 414a of the outer claws 41A, which are on the outer diameter side. The inner claws 41B will therefore tend to saturate much more quickly than the outer claws 41A, thus introducing even harmonics into the electromotive force induced in the multiphase or single-phase stator (and therefore unwanted torque ripple).The two concentric inductors in this sixth example make it possible to deal with these leaks and the problem of asymmetry of the North and South poles, by supplying the 2 inductor coils 40u, 40u' in the opposite direction.

[0138] Of course, this example can be applied with two claw armatures in a similar way to the claw armature of the fourth example instead of the salient pole claw armature 5.

[0139] According to another example (not shown), the machine includes a second claw-type armature identical in shape to that of the fourth example, surrounded by the first claw-type armature, like the claw-type field winding of this sixth embodiment. The second claw-type stator armature then has an external diameter smaller than the internal diameter of the first claw-type stator armature. According to yet another example (not shown), the synchronous machine can be three-phase, comprising a third armature surrounded by the second armature.

[0140] Unless otherwise specified, the same element appearing on different figures has a unique reference.

Claims

CLAIMS

1. Synchronous electric machine (M1, M1', M1”, M1'”, M2, M2', M20, M21, M20') comprising: - a first claw stator inductor (1, 1', 4, 4') comprising: o a claw ferromagnetic body (11, 41) comprising a number Pe of poles and o an inductor coil (10) wound in the ferromagnetic body, - a first stator armature (2, 2', 2u, 5, 5', 5u) comprising a number Pa of poles different from the number Pe, - a ferromagnetic rotor (3, 6, 6') comprising: o an axis of rotation (X) o a first set of ferromagnetic parts (30, 30u, 60, 60u) comprising a number Ns of parts regularly distributed around the axis of rotation (X), the number Ns is equal to the sum of or the difference between Pa / 2 and Pe / 2, the set of ferromagnetic parts (30, 30u, 60, 60u) being located between the first claw stator inductor (1, 1', 4, 4') and the first stator armature (2, 2', 2u, 5, 5', 5u).

2. Synchronous electric machine (M2, M2', M20, M21, M20') according to the preceding claim, in which the first set of ferromagnetic parts (60, 60u) is located axially between the first stator armature (5, 5', 5u) and the first claw stator inductor (4, 4').

3. A synchronous electrical machine (M2”) according to claim 2, comprising a second claw stator inductor (4”) of identical shape to the first claw inductor (4u) and comprising an external diameter smaller than the internal diameter of the first claw inductor, wherein the first claw inductor surrounds the second claw stator inductor (4”).

4. A synchronous electric machine (M1, M1', M1”, M1'”) according to claim 1 wherein the first set of ferromagnetic parts (30, 30u) is located concentrically between the first stator armature (2, 2', 2u) and the first claw stator inductor (1, 1') [Claim s] Synchronous electric machine (M1, M1”, M1'”) according to claim 4 wherein the stator armature (2, 2u) surrounds the first set of ferromagnetic parts (30, 30u) of the ferromagnetic rotor (3) surrounding the claw stator inductor (1, 1u).

6. A synchronous electrical machine (MT) according to claim 4, wherein the first claw stator inductor (1') surrounds the first set of ferromagnetic parts (30) of the ferromagnetic rotor (3) surrounding the stator armature (2').

7. A synchronous electric machine (M1”, M1'”, M2', M20') according to any one of the claims wherein the first stator armature (2u, 5u) is a claw armature. [Claim s] Synchronous electric machine (MT”, M20, M21, M20') according to one of the preceding claims further comprising: - a second inductor (1 v, 4', 4v, 4”) of identical shape to the first inductor (1 u, 4, 4u) and a second stator armature (2v, 5', 5v, 5”) comprising air gap parts, of identical shape to the first stator armature, - in that the rotor (3, 6) further comprises a second set of ferromagnetic parts (30v, 60', 60v, 60”) identical to the first set of ferromagnetic parts (30u, 60, 60u), forming an air gap with the second inductor (1 v, 4', 4v) and being opposite the air gap parts of the second stator armature forming an air gap between them.

9. Synchronous electrical machine (M2) according to one of claims 1 to 7, wherein the armature (5”) comprises teeth (51) having first air gap walls (516) and second air gap walls (516') opposite the first air gap walls (516) by means of a central wall (514), a winding of the armature comprising coils (50u, 50v) each wound in a corresponding tooth (51) around the central wall (514) Tl between the first and second air gap walls (516, 516'), the synchronous electric machine (M21) further comprising: - a second inductor (4') of identical shape to the first inductor (4) and - in that the rotor (6) further comprises a second set of ferromagnetic parts (60') identical to the first set of ferromagnetic parts (60), forming an air gap with the second inductor (4') and being opposite the second air gap walls (516') of the stator armature (5”) forming an axial air gap between them.

10. Three-phase synchronous electric machine (M1 '”, M20') according to one of claims 1 to 7, further comprising: - a second and third inductor (1 v, 1 w, 4v, 4w) identical to the first inductor (1 u, 4u), - a second and third claw stator armature (2v, 2w) identical to the first armature (2u) comprising air gap parts and and in that the rotor (3) further comprises a second and third set of ferromagnetic parts (30v, 30w) identical to the first set of ferromagnetic parts (30u), each respectively forming an air gap with the second and third inductor (1 v, 1w) and being opposite the air gap parts respectively of the second and third stator armature (2v, 2w) forming an air gap between them. [Claim 1 1 ] Synchronous electrical machine according to one of the preceding claims, in which the inductor (1 , 4') comprises inter-claw magnets (13, 43) located in each space formed between two contiguous claws (1 1 a, 1 1 b, 41 A, 41 B) of different polarity.

12. A synchronous electric machine according to any preceding claim, wherein the ferromagnetic claw body (11, 41) of the claw inductor (4”, 4'”) comprises a base (415) and claws (41A, 41B), wherein each claw (41A, 41B) comprises a portion intermediate portion (414a, 414b) extending from the base (415) perpendicular to the base (415) and an air gap portion (413a, 413b) extending from the intermediate portion (414a, 414b) parallel to the base (415), the inductor coil (40) being wound in an area formed between the base (415), the intermediate portion (414a, 414b) and the air gap portion (413a, 413b) of each claw (4”, 4'”), and wherein the claw inductor (4”, 4'”) further comprises an inter-claw-base magnet (45) per claw, each located between the base (415) and a free end of the intermediate portion (414a, 414b) of the corresponding claw (41 A, 41 B).

13. Synchronous electric machine according to one of the preceding claims, wherein the ferromagnetic claw body (1 1 , 41 ) comprises a material formed from compressed powder.

14. Synchronous electrical machine according to one of the preceding claims, comprising a cooling liquid circuit, in which the inductor is immersed, in particular in a dielectric liquid.

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