synchronous electric machine with fixed claw inductor

Abstract

Synchronous electric machine with fixed claw inductor. One aspect of the invention relates to a synchronous electric machine (M1, M1', M1'', M1''', M2, M2', M20, M21, M20') comprising: a first stator claw inductor (1, 1', 4, 4') comprising a ferromagnetic claw 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: a rotation axis (X), a first set of ferromagnetic parts (30, 30u, 60, 60u) comprising a number Ns of parts regularly distributed around the rotation axis (X), the number Ns being 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 stator inductor with claws (1, 1', 4, 4') and the first stator armature. Figure to be published with the abbreviation: Figure 2

Description

Title of the invention: 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] The synchronous machine comprises, like any electric motor, a rotor and a stator, mainly the rotor forms the inductor and the stator forms the armature. In the state of the art, two ways of making an inductor of a synchronous electric machine are known, those wound and those with magnets. The inductor can have an advantage in being wound. Indeed, a machine with a wound iron core can produce a higher induction than those with magnets which are also more expensive and thermally limited by their characteristics than a coil. Thus at iso volume, a synchronous electric machine comprising a magnet inductor will be more expensive, more thermally limited and less efficient (torque) particularly at high rotation speed than a machine compared to an electric machine comprising a wound inductor.

[0004] There are also mainly two main families of air gaps known in electrical machines.

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

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

[0007] The flux is mainly radial called radial field in a radial air gap machine and is mainly axial called axial field in an axial air gap machine but there are also known claw rotor synchronous machines whose flux includes radial and axial components (whether with radial or axial air gap). These claw rotor machines have flux loops not contained in a plane. In other words, each of the loops is three-dimensional, called a left curve, as opposed to a plane curve. For example, there are alternators or alternator-starters comprising a rotor inductor comprising an inductor coil and two half-pieces pole pieces comprising claws. The two pole pieces are assembled together to enclose the coil by means of the claws. The stator armature comprises coils wound in slots of several slotted laminations. The armature coils convert the flux variation as the rotor field turns into induced voltage, thus generating electric current.

[0008] Having a coil and two pole pieces with claws fitted one on top of the other has the advantage of making the rotor easy to manufacture and therefore reduces the cost while having fewer losses since the entire coil is used. However, as in magnet inductor rotors, the claws are subject to elastic deformation by centrifugal force, requiring a sufficiently large air gap depending on the manufacturing tolerances of the internal diameter of the armature and the external diameter of the claws. However, the larger the air gap, the lower the performance of the synchronous electrical machine. In addition, the wound inductor rotor requires brushes and two rings to power the coil of the inductor rotor.However, as explained above, the advantage of varying the inductive flux allows either to have a higher force and therefore a higher torque (at low speed) or when the inductive current is reduced, allows to lower the magnetic losses at high speed for the same dimension of the electrical machine.

[0009] There is therefore a need to have a synchronous electrical machine architecture having both the advantage of a wound inductor while having fewer disadvantages than a claw rotor electrical machine. Summary of the invention

[0010] The invention provides 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 stator inductor comprising a claw 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 stator inductor and the first armature stator.

[0012] Thanks to the invention, the synchronous electric machine has a wound stator claw inductor which combines several advantages: • The advantage of the coil allowing to have a high inductance than with 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 comprises ferromagnetic parts (without claw shape). • The advantage of not having a bun and therefore using the entire coil and therefore the ampere turns of the inductor coil for each pair of poles, and thus producing a magnetic field with significantly less Joule losses than with a bun to produce the magnetic flux.

[0013] Otherwise, the synchronous electric machine according to the invention has the advantages of a claw synchronous 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 inductor (Pa being different from Pe) allows the rotor to modulate the flux between the stator armature 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 which have just been mentioned in the preceding paragraph, the synchronous electrical machine according to one aspect of the invention may have one or more complementary characteristics among those of the following paragraphs, considered individually or according to all technically possible combinations.

[0016] According to one embodiment, the ferromagnetic rotor is located axially between the first stator armature and the first claw stator inductor. Thus, in this case, the air gap is axial. The magnetic flux produced by the stator armature and the stator inductor is modulated by the set of ferromagnetic parts and passes axially through the air gap.

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

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

[0019] According to an example of this embodiment, the first claw 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] According to one embodiment, the first stator armature is a claw armature. This makes it possible to use the entire coil and therefore to have better efficiency.

[0022] According to one example, the claw stator armature comprises a first block comprising 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 shape identical to the first claw stator armature, and • 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 is meant the geometric shape but not the dimensions, thus a first inductor may be larger in size than the second inductor.

[0025] According to an implementation of this example of this embodiment, the machine further comprises: • a third inductor of identical shape to the first inductor, • a third stator armature with claws of identical shape to the first block comprising air gap parts and • 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 of having an armature which can be supplied by or restore a three-phase alternating voltage. In fact, each armature can thus form a phase.

[0027] According to an example of this embodiment, the machine further comprises: • a second claw stator inductor of identical shape to the first claw stator inductor and • a second claw stator armature of identical shape to the first claw stator armature, • a second rotor mechanically decoupled from the first rotor comprising a set of ferromagnetic parts located between the second claw stator inductor and the second claw stator armature, • in which either the two claw stator armatures or the two claw inductors are monobloc by sharing their 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 distant from each other.

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

[0029] According to an embodiment which is a variant of the previous 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, a winding of the armature comprising coils each wound in a corresponding tooth around the central wall between the first and second air gap walls, the synchronous electrical machine further comprising: • a second inductor of identical shape to the first inductor 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 inductor 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 parts and • and in that the rotor further comprises a second and third set of ferromagnetic parts identical to the first set of ferromagnetic parts, each respectively forming an air gap with the second and third inductor and being opposite the air gap parts respectively of the second and third stator armature forming between them a air gap.

[0031] According to one embodiment, the ferromagnetic claw body of the claw inductor comprises a base and claws, wherein each claw comprises 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 being wound in an area formed between the base, the intermediate portion and the air gap portion, and wherein the claw inductor further comprises inter-claw-base magnets per claw, each located between the base and a free end of the intermediate portion of the corresponding claw. This makes it possible to increase the magnetic saturation level of the claw and therefore to have a greater inductor current before saturation and therefore the possibility of having more torque. That is to say that a claw without a magnet will be magnetically saturated 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 contiguous claws of different polarity.

[0033] According to one embodiment, the first ferromagnetic body of the claw 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] According to one embodiment, the electrical machine comprises a cooling liquid circuit, in which the inductor is immersed, in particular in a dielectric liquid. This makes it possible to be cooled much more easily than a rotating inductor structure, in fact this cooling technique is direct, thus offering higher performance than a non-cooled or less cooled structure.

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

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

[0037] The figures are presented for information purposes only and in no way limit the invention.

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

[0039] [Fig.lB] 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 machine synchronous electric 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 three-dimensional view partial, 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 machine synchronous electric according to the second example of a first embodiment.

[0044] [Fig.6] shows a schematic representation in a three-dimensional view of a 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 electric machine according to a third example of the first embodiment.

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

[0047] [Fig.9] shows a schematic representation of an electric machine section synchronous 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.lOB] shows a schematic representation of a ferromagnetic claw body and inter-claw magnets of a second example of a claw stator inductor of the synchronous electric machine according to the first example of the second embodiment.

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

[0052] [Fig. 11] 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 an electrical machine synchronously according to a second example of the second embodiment.

[0055] [Fig.l3B] shows a schematic representation of a synchronous electrical machine according to a third example of the second embodiment.

[0056] [Fig.l3C] shows a schematic representation of a 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 information purposes only and in no way limit the invention.

[0062] By rotor is meant an element which rotates on itself according to its own axis of rotation.

[0063] By a stator element is meant 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 [Fig.8] show a schematic representation of the synchronous electric machine M1 or a part thereof according to examples of the first embodiment and Figures 9 to [Fig.17] show a schematic representation of the synchronous electric machine M2 or a part thereof according to examples of the second embodiment.

[0066] In both embodiments, the synchronous electrical machine M1, M2 comprises at least: • a first claw stator inductor 1, 4 comprising a ferromagnetic claw body 11, 41 comprising a number Pe of poles and an inductor coil 10, 40 wound in the ferromagnetic body 11, 41, • a first stator armature 2, 5 comprising a number Pa of poles different from the number Pe, • a ferromagnetic rotor 3, 6 comprising: • an axis of rotation • a first set of ferromagnetic parts 30, 60 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 30, 60 being located between the first claw 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 claw stator inductor 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 claw stator 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 claw stator inductor 4.

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

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

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

[0072] [Fig.2] shows a schematic representation of a radial section of the synchronous electric machine Ml 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 sheet metal package 21. The winding 20 comprises three coils 20u, 20v, 20w each forming a phase of a three-phase system. Of course, the winding can comprise more than three coils, for example five or six forming for example a double three-phase system.

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

[0075] In this example, the first stator armature 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 comprises 8 ferromagnetic parts 30 and the claw inductor 1 of the machine comprises an inductor coil 10 corrugated 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 stator inductor 1 of the synchronous electric machine Ml according to a second example of a first embodiment.

[0078] The claw stator inductor 1 comprises in this case a ferromagnetic claw body 11 comprising a first base comprising a first base 115a and first claws 11a of a first polarity each extending axially from the base 115a and a second polar base comprising a second base 115b and second claws 11b of the other polarity each extending axially from the second base 115b towards the first base 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 bases 115a, 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 facing the ferromagnetic rotor 3 not shown here. The air gap portion 113a, 113b comprises an outer surface facing the ferromagnetic parts 30, together forming the radial air gap (in the form of a cylinder). The outer diameter of the claws 11a, 11b is therefore measured at this outer surface of the air gap portion 113a, 113b. The inductor coil 10 is located axially in the ferromagnetic body with claws 11 between the first and second pole bases. The first and second polar bases each comprise Pe / 2 claws, here in this case 6 claws, each forming a pole, i.e. in this example the claw stator inductor 1 comprises a number Pe of poles = 12, i.e. 6 pairs of poles.

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

[0080] The claw stator inductor 1 further comprises 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 Ml comprises the claw stator inductor of [Fig.3] and the armature of [Fig.2], the ferromagnetic rotor must therefore comprise a number Ns = 5 + 6=ll of ferromagnetic parts 30.

[0082] [Fig.4] shows another example of a claw 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 sheet stacks 110, only two of which are shown. Each sheet stack 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 stack of sheets 110 comprises an axial base 115 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 11a, 11b, each extending from a corresponding end (opposite one another) of the base 115.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 facing the ferromagnetic rotor 3 not shown here. The sheets of the sheet stack are intertwined towards each other by being folded against each other so that each claw is formed.

[0083] Thus the first sheet of a pack of sheets 110 comprises: • a first air gap part forming a portion of a first claw juxtaposed with another claw of another pack of sheets and • a second air gap part forming a portion of a second claw juxtaposed with the first part of the last sheet of the first claw of the stack of sheets.

[0084] In this example, optionally, each air gap portion 113 of each claw comprises a projection towards the rotor 3 (in this example towards the outside) but could also be flat. The ferromagnetic parts can then have an internal groove partly surrounding these projections.

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

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

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

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

[0089] Of course, the stator ferromagnetic body 11 of the claw stator inductor 1' may comprise stacks of sheets as in the example of [Fig.4] except in that the air gap parts are towards the inside, that is to say comprise an internal surface facing the ferromagnetic parts 30 of the rotor 3.

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

[0091] In this example, the number Ns of ferromagnetic parts 30 is equal to 11, visible in [Fig.5].

[0092] The stator armature 2' comprises in this example a sheet metal package 20 whose notches are open towards the outside. The winding 20 is thus wound in the external notches, and can comprise, as in the previous example, three coils. In this example, the notches are 42 in number, i.e. 7 pairs of poles, Pa / 2 = 7, Ns = 11 and Pe / 2 equal to 4.

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

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

[0095] The claw stator armature 2u is similar to the claw 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 axially nested against each other such that each claw of the first pole base 21a is angularly located between two claws of the second pole base 21b. Each claw is shown either in dotted lines or has a dotted portion to improve understanding. Each claw comprises an air gap portion 23 having an inner surface facing the air gap pieces 30 of the rotor 3. The inner diameter of the claw 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 base 21a and the second pole base 21b may be identical and are simply axially fitted against each other while being angularly offset by one claw. The coil 20u' is therefore located axially between the first and second pole bases 21a, 21b between the internal air gap parts 23 of each claw and the external base 210 of each pole base surrounding the armature coil 20u'. Of course, the armature body 21u may also be formed from a stack of sheets as in the example of the inductor in [Fig.4]. The armature body may also be formed from a single block with the claws folded towards each other.

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

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

[0098] [Fig.8] schematic representation of a synchronous electric machine Ml'” 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 2v, 2w armature identical to the first 2u armature, • two other claw stator inductors Iv, Iw identical to the first claw stator inductor read from the third example, • and in 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 armature 2v, 2w respectively 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 other coil 20v', 20w' each mounted in the second and third second and third armature body 21v, 21w. The first and second armature body 21v, 21w comprises air gap portions facing the respectively second and third set of ferromagnetic parts 30v, 30w. This synchronous electric machine Ml'” makes it possible to have three armature coils 20u', 20v', 20w' each being able to be supplied in mode motor or restored in alternator mode (AC generator) a three-phase voltage.

[0100] The first, second and third sets of ferromagnetic parts 30u, 30v, 30w or the air gap parts of the first, second third claw stator armature 2u, 2v, 2w are angularly offset from each other according to the number of ferromagnetic parts or claws respectively. According to another example, it is the claws of the first, second, third claw stator inductors lu, Iv, Iw which 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 claws respectively.

[0101] According to another example not shown, the synchronous electric machine is different from the fourth example in that the claw stator inductor 1 comprises only the first ferromagnetic body 11 extending axially along the entire length of the rotor 3 with a single inductor coil 10.

[0102] According to another example not shown, the synchronous electric machine is different from the fourth example in that the claw stator inductor 1 surrounds the rotor 3 surrounding the three claw 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, on the one hand, the rotor and the armature and, on the other hand, the rotor and the inductor. A synchronous electrical machine will now be described according to a second embodiment identical to the first example except that the air gaps between, on the one hand, the rotor and the armature and, on the other hand, the rotor and the inductor are axial. The various options and characteristics of the examples described previously can be applied to the first example when this does not concern the geometric shape of the armature, the rotor and the inductor involving 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 comprises a first claw stator inductor 4 comprising a ferromagnetic claw body 41 comprising a number Pe of poles and an inductor coil 40 wound in the ferromagnetic claw body 4L. Four different examples of claw stator inductors 4A, 4B, 4C, 4D will be described in FIGS. 10A to 10D which may be the first claw stator inductor 4.

[0106] [Fig.10A] shows a schematic representation according to a three-dimensional view of a first implementation of a 4A claw stator inductor in 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 being located in the ferromagnetic claw body 41. The ferromagnetic claw body 41 is represented transparently. The ferromagnetic claw body 41 comprises a crown-shaped base 415 (comprising a central orifice for supporting a rotor shaft using a bearing) but could be a (solid) disc. The ferromagnetic claw body 41 comprises external claws 41A extending from the external perimeter of the base 415 having a first polarity, for example South, and internal claws 41B extending from the internal perimeter of the base 415 of the other polarity, in this example North (the polarity is according to the direction of the current flowing in the inductor coil 40). In this example, the number of external claws 41A is equal to 6 and the number of internal claws 41B is equal to 6, i.e. 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 from the base 415, radially towards the rotor 6 and an air gap portion 413a, 413b facing the first set of ferromagnetic parts 60 together forming an axial air gap. The air gap portion 413a of an external claw 41A extends from the intermediate portion 414a inwards, in this case by reducing its width, while the air gap portion 413b of an internal claw 41B extends from the intermediate portion 414b outwards, in this case by increasing its width.

[0108] [Fig.10B] shows a schematic representation according to a three-dimensional view of a second implementation of a claw stator inductor 4B of the synchronous electric machine M2 according to the first example of the second embodiment. The claw stator inductor 4B according to this second implementation is identical to the first implementation except in that it comprises inter-claw magnets 43 located in each space formed between two contiguous claws 41A, 41B of different polarity. In other words, each inter-claw magnet 43 is located between an air gap portion 413a of an external claw 41A, and an air gap portion 413b of an external claw 41B.

[0109] [Fig.10C] shows a schematic representation according to a three-dimensional view of a third implementation of a claw stator inductor 4C of the synchronous electric machine M2 according to the first example of the second embodiment. The claw stator inductor 4C is identical to the first implementation except in that it comprises one 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 outer claw 41A or inner claw 41B, and the base 415.

[0110] [Fig.10D] shows a schematic representation according to a three-dimensional view of a fourth implementation of a 4D claw stator inductor of the synchronous electric machine M2 according to the first example of the second embodiment. The 4D claw stator inductor is identical to the first implementation, except in which includes an inter-claw-base magnet 45 per claw and an inter-claw magnet 43 between each claw.

[0111] According to a feature of one of these implementations, the ferromagnetic body with claws 11, 41 comprises a material formed from compressed powder. Such a powder with such magnets has the feature of increasing the capacity of the ferromagnetic body before saturation.

[0112] [Fig. 11] 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 comprises an armature body 51 with salient poles comprising a base 510 in the form of a crown and a plurality of teeth 511 forming notches between them (here 12 teeth and notches in number).

[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 in this case extends circumferentially on either side of the central wall 514 partially closing the notches axially. The armature body 51 may be formed of several sheets wound concentrically within each other or of a sheet wound like a spiral. The stator armature 5 comprises in this example a winding 50, in this case concentric, comprising 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 511 of the armature body 51. The stator armature 5 comprises 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 notch per pole and per phase, i.e. a number Pa 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 according to a three-dimensional view. The ferromagnetic rotor 6 is in this case internal and comprises a rotation shaft 61 along its rotation axis X (not visible in [Fig. 12], but visible in [Fig.9]). Of course, the rotor 6 can, according to another example, be external.

[0117] The ferromagnetic rotor 6 comprises the first set of ferromagnetic parts 60 regularly distributed around the rotation axis X, each ferromagnetic part is mounted on a crown 62 secured 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 10 in number, i.e. Pa / 2 + Pe / 2, but could also be 2 in number (the difference). The set of ferromagnetic parts 60 being located axially between the first claw stator inductor 4 and the first armature stator induced stator 5.

[0118] [Fig. 13A] shows a schematic representation of an electrical machine synchronous 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: • in that it further comprises a second inductor 4' identical to the first inductor 4, in this case as one of the different examples represented in one of figures 10A to 10D of the first example; • 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 axial air gap with the second inductor 4' and in that it comprises a second stator armature 5' identical to the first stator armature 5, in this case like that shown in [Fig. 11] 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 base 415 in the form of a crown against the base 415 of the first inductor 4' with the air gap parts 413a, 413b of each internal and external claw 41b, 41a facing the second set of ferromagnetic parts 60' together forming an axial air gap. The armature body 51 with salient poles of the two inductors 4, 4' may be in one piece.

[0121] The coils of the second stator armature 5' can be coupled in parallel to 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.l3B] shows a schematic representation of an electric 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” stator armature with through flux, similar to the first stator armature 5 of the first example except in that it has no base and in that each tooth 511' shown in a section in [Fig.l3C], comprises a second air gap wall 516 opposite the second set of ferromagnetic parts 60' forming an axial air gap between them and in that • the second claw inductor 4' is axially opposite the first 4 claw inductor.

[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' opposite the first air gap wall 516 by means of the central wall 514 of the through-flux stator armature 5”. The teeth 511' may be connected to each other by a non-ferromagnetic part, for example by a resin. In other words, this stator armature 5” is devoid of a yoke. Each coil of each tooth 51' of the stator armature 5” each produces a through-flux from the first to the second air gap wall 516. In other words, the flux passes from the first inductor 4 to the second inductor 4' by means of 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 have claws as in the third example of the first embodiment (except in that the armature has an axial air gap.

[0130] In these two examples, having a rotor having two sets of ferromagnetic parts axially offset from each other makes it possible to reduce 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 inductor 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 inductor.

[0131] [Fig. 14] shows a schematic representation of a synchronous electric machine section M2' according to a fourth example of the embodiment identical to the first example of this second embodiment except that the stator armature 5u is claw-type. In this fourth embodiment, the stator armature 5u is similar to the claw-type stator inductor 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 synchronous electrical machine M2' can be multi-phase, in which case it comprises 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 multi-phase in this case three-phase.

[0134] The synchronous electric machine M20' is therefore identical to the fourth example embodiment except that it includes: • a second and a third 5v, 5w claw stator armature identical to the first 5u claw stator armature of the fourth example of this embodiment, respectively comprising a second and third other 50v, 50w coils each mounted in the second and third 51v, 51w armature body, • a second and third claw inductor 4v, 4w identical to the first claw stator inductor 4u of the fourth example of this embodiment, respectively comprising a second and third other inductor coils 40v, 40w each mounted in the second and third second and third ferromagnetic body 41v, 41w, and • in that the rotor 6” comprises a second and third set of ferromagnetic parts 60v, 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 claw inductors 4u, 4v, are monobloc and the second and a third claw stator armature 5v, 5w are monobloc, that is to say that they can comprise a common base. In these different examples the different inductors and the different armatures are stacked axially one after the other while keeping a rotor having two sets of ferromagnetic parts offset from each other axially.

[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 synchronous electric machine M2' according to the first example except in that it further comprises a second claw stator inductor 4'' comprising 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 claw stator inductor 4”. [Fig. 17] shows an axial view of the first and second claw inductors 4, 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 41A of the first inductor 4 is radially contiguous with an internal claw 41B of the second inductor 4”.

[0137] A Claw Inductor may exhibit magnetic flux leakage, particularly when the inner diameter is much smaller than the outer diameter. The axial air gap solution exhibits geometric asymmetries between the inner claws 41B and the outer claws 41A. As can be seen in Figures 10A to 10D, the intermediate portions 414b are less wide (measured in the circumferential direction) than the outer portions 414b. conferential) on the internal claws 41B which are on the inner diameter side than the intermediate parts 414a of the external claws 41A which are on the outer diameter side. The internal claws 41B will therefore tend to saturate much faster than the external claws 41A, thus introducing even harmonics into the Electromotive Force induced in the multi-phase or single-phase Stator (and therefore unwanted Torque Ripples). The two concentric inductors of 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 comprises a second claw armature of identical shape to that of the fourth example surrounded by the first claw armature like the claw inductor of this sixth embodiment. The second claw stator armature then comprises an external diameter smaller than the internal diameter of the first claw 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 in different figures has a single reference.

Claims

Claims

1. Synchronous electric machine (Ml, Ml', Ml”, Ml'”, M2, M2', M20, M21, M20') comprising: - a first claw stator inductor (1, 1', 4, 4') comprising: • a claw ferromagnetic body (11, 41) comprising a number Pe of poles and • 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: • an axis of rotation (X) • 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 (Ml, Ml', Ml”, Ml'”) 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')

5. Synchronous electric machine (Ml, Ml”, Ml'”) 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, lu).

6. A synchronous electric machine (Ml') 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 (Ml”, Ml”', M2', M20') according to any one of the claims wherein the first stator armature (2u, 5u) is a claw armature.

8. Synchronous electric machine (Ml'”, M20, M21, M20') according to one of the preceding claims further comprising: - a second inductor (Iv, 4', 4v, 4”) of identical shape to the first inductor (lu, 4, 4u) and - a second stator armature (2v, 5', 5v, 5”) comprising air gap portions, 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 (Iv, 4', 4v) and being opposite the air gap portions 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) between the first and second air gap walls (516, 516'), the synchronous electrical 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 electric machine (Ml'”, M20') synchronous (Ml”', M20') according to one of claims 1 to 7, further comprising: - a second and third inductor (Iv, Iw, 4v, 4w) identical to the first inductor (lu, 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 (Iv, Iw) and being opposite the air gap parts respectively of the second and third stator armature (2v, 2w) forming an air gap between them.

11. 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 (11a, 11b, 41A, 41B) 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 an 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 in which 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 part (414a, 414b) of the corresponding claw (41 A, 41B).

13. A synchronous electric machine according to any preceding claim, wherein the ferromagnetic claw body (11, 41) comprises a compressed powder-formed material.

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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