WO2011092434A1 - Magnetocaloric device. - Google Patents

Abstract

The invention relates to a rotating machine (1), inside a peripheral yoke (3), for producing a variable magnetic field with a maximum intensity greater than 1 tesla, said machine comprising, rotating about a rotation axis (2) inside a bore (6) that includes said yoke (3) or said exchanger (4) and separated from said bore by a first gap (7A), a rotor (5) having an external surface of revolution (9) and a first even number (n) of poles. The machine is characterized in that said rotor (5) has an internal surface of revolution (10) and that said rotating machine (1) includes, inside said rotor (5) and being separated from said second internal surface of revolution (10) by a second gap (7B), a stator (11) creating a magnetic field and capturing a portion of the magnetic flux emanating from said rotor (5) in order to make the latter rotate under the effect of an electromagnetic torque, said stator (11) itself comprising a second even number (N) of stator poles.

Description

 MAGNETOCALORIC DEVICE

The invention relates to a rotating machine, around an axis of rotation inside a peripheral yoke, for producing a variable magnetic field and a maximum intensity greater than a Tesla, for effecting a variation of said field by a point of an exchanger located at said cylinder head, according to a substantially square diagram as a function of time, said machine comprising, movable in rotation about said axis of rotation within a bore that includes said cylinder head or said exchanger and separated from said bore by a first air gap, a rotor having a first external surface of revolution about said axis of rotation, said rotor having a first even number of poles constituted by an assembly of flow concentration means, and said cylinder head being adapted to looping the magnetic field lines generated by said rotor.

 The invention also relates to a high power self-cooling synchronous motor greater than 500kw comprising a rotating machine according to the invention.

 The present invention more particularly in the field of synchronous machines.

It is known from WO 3005/043053 a magnetocaloric heat flux generation device having a first support comprising thermal organs composed of gadolinium-type magnetocaloric material or the like. These thermal elements also comprise a cavity allowing the passage of an exchanger comprising a heat transfer fluid, for the purpose of heating or cooling. Moreover, the magnetocaloric material is surrounded by copper in order to transmit the calories or frigories created. Indeed a magnetocaloric material creates calories when it is subjected to a strong magnetic field B and cooled, creating frigories, when no longer subject to it. This first support is coaxial with a second mobile support comprising permanent magnets allowing the creation of the magnetic field. This mobile support is driven by an external motor controlled by alternating current and pivots on its axis in two positions so as to subject or not the thermal organs to the magnetic field.

 Such a device has a variable magnetic field of low intensity in the thermal organs which does not allow it to have a good performance. In addition, it has a large dimensioning due to the need for a large amount of embedded copper to efficiently transmit the heat of the magnetocaloric material to the exchanger comprising the heat transfer fluid and its manufacturing cost is high.

 It is also known from FR 3 904 098 a thermal generator in the form of a cylinder comprising cylindrical thermal modules consisting of a plurality of thermal elements of magnetocaloric material delimiting channels provided with two separate collectors, alternatively, a hot collector circuit and a cold collector circuit. These annular thermal modules and stacked axially on a rotating shaft are subjected to a variation of a magnetic field by permanent magnets, which includes the rotating shaft, to create, thanks to the magnetocaloric effect frigories and calories. This rotating shaft is then actuated by an electric motor to create, on these annular thermal modules, alternately, areas subject to a magnetic field and areas not subject to this field and therefore calories and cold collected by the collector circuit. The generator also includes a ferromagnetic frame surrounding the thermal modules and to close the magnetic field generated by the magnets.

 Here again such a thermal generator has a large dimensioning and a high manufacturing cost.

The invention proposes to solve the disadvantages of the state of the art in that it proposes a rotating machine with integrated actuator capable of generating a strong field electromagnetic variable with great ease of implementation and low manufacturing cost.

 Thus, the invention relates to a rotating machine, around an axis of revolution inside a peripheral yoke, for producing a variable magnetic field and a maximum intensity greater than a Tesla, for effecting a variation of said field. at a point of an exchanger located at said cylinder head, according to a substantially square diagram as a function of time, said machine comprising, movable in rotation about said axis of rotation inside a bore that includes said cylinder head or said exchanger and separated from said bore by a first gap, a rotor having a first outer surface of revolution about said axis of revolution, said rotor having a first even number of poles constituted by an assembly of flow concentration means, and said cylinder head being designed capable of looping back the magnetic field lines generated by said rotor, characterized in that said rotor comprises a second surface i revolution of revolution about said axis of revolution, and said rotating machine comprises, inside said rotor and being separated from said second internal surface of revolution by a second air gap, a stator designed to create a magnetic field and designed able to sensing a portion of the magnetic flux emanating from said rotor to rotate the latter under the effect of an electromagnetic torque, said stator itself having a second even number of stator poles.

 Other features and advantages of the invention will emerge from the following detailed description of non-limiting embodiments of the invention, with reference to the appended figures in which:

Figure 1 shows, in perspective and schematically, the rotating machine according to the invention; FIG. 2 represents, from the front and in a schematic form, the rotating machine according to the invention including all the axes and directions mentioned in the description;

FIG. 3 represents, from the front and in a schematic form, the rotating machine according to a first embodiment of the invention;

FIG. 4 represents, from the front and in a schematic form, the rotating machine according to another embodiment of the invention;

Figure 5 shows, front and schematically, a portion of the exchanger of the rotating machine according to the invention;

FIG. 6 represents, from the front and in a schematized manner, the rotating machine according to the invention with the directions of magnetization of the magnets that the rotary machine comprises;

FIG. 7 represents a graph of the profile of the induction obtained in the gap of the rotating machine according to the invention;

Figure 8 shows, front and schematically, induction and field lines in the center of the exchanger of the rotating machine according to the invention;

Figure 9 shows, front and schematically, a hexagonal magnet that includes the rotating machine according to the invention;

FIG. 10 represents, from the front and in a schematized manner, a trapezoidal magnet that comprises the rotating machine according to the invention;

Figure 11 shows, front and schematically, a rectangular magnet that includes the rotating machine according to the invention;

Figure 12 shows, front and schematically, the arrangement of the hexagonal, trapezoidal and rectangular magnets that comprises the rotating machine according to the invention; and 13 shows, from the front and schematically, the rotating machine according to the invention with the hexagonal magnets, trapezoidal and rectangular that includes the rotating machine. As can be seen in FIG. 1, the invention relates to a rotating machine 1 around an axis of rotation 2 inside a peripheral yoke 3, for producing a variable magnetic field B and greater maximum intensity. to a Tesla.

 In this connection, it will be observed that in order to achieve a variation of the field B at a point of an exchanger 4 situated at the level of the yoke 3, according to a substantially square diagram as a function of time, the rotating machine 1 comprises a rotor 5 movable in rotation around the axis of rotation. The rotor 5 is preferably placed inside a bore 6 that includes the yoke 3 or the exchanger 4.

 The rotor 5 is separated from the bore 6 by a first gap 7A.

 In this configuration the yoke 3, preferably made of steel, comprising the rotor 5 is designed capable of looping magnetic field lines B generated by the rotor 5, and to mechanically protect the assembly.

 Advantageously, the rotor 5 has a first external surface of revolution about the axis of rotation 2, and a first even number n of poles constituted by flux concentration means 8. Included in its first external surface of revolution 9, the rotor 5 has a second inner surface of revolution 10 about the axis of rotation 2.

In particular, the rotating machine 1 comprises, inside the rotor 5, and being separated from the second inner surface of revolution 10 by a second gap 7B, a stator 11 designed to create a magnetic field B and designed to capture a part of the magnetic flux emanating from the rotor 5 to put the latter in rotational movement under the effect of a electromagnetic torque, the stator 11 itself having a second even number N of stator poles.

 Preferably, the rotor 5 rotates at an operating frequency of the order of a few tens of Hertz.

As can be seen in FIG. 2, the rotary machine 1 therefore has an inverted structure, that is to say that the stator 11 is placed at the center of the rotary machine 1 with the rotor 5 moving around the periphery of the stator 11. Inverted structure advantageously makes it possible to obtain an induction profile in the center of the exchanger 4 of relatively high amplitude, of substantially square shape and being canceled for approximately Π / ^{η and} preferably Π / 3.

 To this is added the fact that, in a particular version of the invention, the stator 11 is twisted to reduce the electromagnetic torque ripple and advantageously obtain a sinusoidal electromotive force.

 In addition, the design of the rotary machine 1 is performed in such a way that a maximum induction variation ΔΒ is obtained in the first gap 7A.

 In a first embodiment and as visible in Figure 3, to facilitate obtaining such an induction profile, the exchanger 4 of the rotating machine 1 is integrated in the cylinder head 3, which comprises the bore 6, this exchanger 4 being located in the vicinity of the first gap 7A, so as to be traversed by a magnetic field of high density.

Such an exchanger 4 is more particularly in the form of a cylindrical chamber, the dimensions of which are adapted to the width of the first air gap 7A that the rotary machine 1 comprises. This chamber is preferably divided into several cells 12 of identical dimensions which are intended to comprise a magnetocaloric effect material, in particular comprising gadolinium, for example in the form of lamellae. The exchanger 4 exchanges the energy that it perceives or that it emits with a circuit of use, preferably traversed by a coolant. Advantageously, such a magnetocaloric material is designed capable of exchanging energy with a heat transfer fluid under the effect of the variation of the magnetic field B.

 To return to the cells 12 of the exchanger 4 and as visible in Figure 5, the latter are provided, in whole or in part, plates or strips 13 made of magnetic material having a curie point close to the ambient temperature and having a giant magnetocaloric effect and, preferably, gadolinium, this to advantageously limit the effects of the magnetic torque, in particular the interactions between the magnetocaloric material and the source of the magnetic field B.

 In this respect, a magnetocaloric material subjected to a strong magnetic field B heats up and thus creates calories, then, when it is no longer subject to this field B will go down to a lower temperature than it had to the origin allowing, in particular, the creation of frigories.

 It is therefore easy to understand the advantage of obtaining a maximum induction variation ΔΒ in the first air gap 7A since this induces a high temperature variation ΔΤ thus improving the performance of the magnetocaloric exchanger 4.

 The integration of the exchanger 4 in the vicinity of the first air gap 7A of the rotating machine 1 allows to share the functions of magnetocaloric inductor and rotor 5 of the rotating machine 1. This grouping advantageously allows to minimize the mass of magnets or coils used in the operation of the machine 1, but also to reduce its size and mass.

 According to another embodiment of the invention, the exchanger 4 is interposed between the yoke 3 and the first gap 7A and comprises the bore 6, as visible in FIG.

In a particular and advantageous application of the invention, the rotor 5 of the rotating machine 1 is designed capable of driving one or more pumps circulating the coolant inside the exchanger 4 and the use circuit, which improves the overall efficiency of the machine 1 and reduce its bulk.

 According to the invention and as visible in FIGS.

6, 8 and 13, in a preferred embodiment, the fixed stator 11 of the rotary machine 1 comprises at least six stator poles.

 Advantageously, the rotor 5 has a first number of rotor poles equal to four.

 According to a preferred embodiment of the invention, the number n of pairs of rotor poles is different from the number N of pairs of stator poles.

 Preferably having four rotor poles and six stator poles allows optimum performance of the machine while having a small footprint. In addition, these values make it possible to obtain very clear induction slots in the rotary machine 1, as can be seen in FIG. 7 in absolute value.

 Advantageously, to further improve these induction slots in the rotating machine 1, the latter comprises control means designed capable of controlling the stepwise rotation of the rotor 5, by a suitable supply of the stator 11.

 To return to the stator poles, they are in the form of 14 teeth wound and allow the creation of a magnetic field when they are fed with a current.

 It is also at these teeth 14 that the rotating machine 1 comprises sensors connected to speed regulation means by regulating the current delivered to the coils that the stator 11 comprises.

Preferably, the rotating machine 1 is provided with control means (not shown) designed to control the different parameters of the rotary machine 1. More particularly, these control means act on the means of speed regulation, on the variation of the stator current, on the stator temperature or on the circulation of the coolant in the exchanger.

 Advantageously, these sensors are Hall effect sensors arranged on several of the teeth 14 of the stator 11. Each Hall effect sensor is notably placed in a notch that has a tooth 14. Preferably, when the stator 11 has six poles, three sensors are arranged at 130 ° on the stator 11.

 According to another characteristic of the invention, the stator coils 11 are supplied with current by power supply means designed to feed the stator 11 periodically, that is to say, alternately, thus creating a magnetic flux as well. alternative at the rotor 5.

 According to another embodiment of the invention, the coils of the stator 11 are still powered by power supply means adapted to supply them with current pulses or by a sinusoidal signal to obtain a sinusoidal flux distribution.

 The stator 11 is thus fed via the coils by a current to create a magnetic field B and thus drive the rotor 5 via the flux concentration means 8 that it comprises.

 Moreover, the flux concentration means 8 of the rotor 5 are composed of induction coils or permanent magnets 15. The rotor 5 of such a rotating machine 1 may be straight in order to provide good induction within it but it can be twisted to improve the shape of the magnetic field in the first gap 7A.

 Advantageously, the flux concentration means 8 consist of an assembly of permanent magnets 15.

Preferably, the arrangement of this magnet assembly 15 results from an inventive step of refining a Halbach structure to obtain looping and concentration of flux at a point of the exchanger 4. Advantageously and as visible in FIG. 6, the flux concentration means 8 of the rotor 5 comprise an assembly of permanent magnets 15 advantageously making it possible to reduce the bulk and the mass in the rotor 5. the longer these permanent magnets 15 are easier to implement than a winding. They may be of any type but they are, preferably, neodymiron-boron having a remanent induction of greater than 1 Tesla and ideally having the highest possible remanent induction.

 In this regard, it will be observed that each pole of the rotor 5, extending between the first gap 7A and the second gap 7B, is formed by a permanent magnet assembly 15.

 Preferably, the assembly of permanent magnets 15 comprises, developing substantially prismatically or helically relative to said axis of rotation 2, at least one magnet 16 having a parallel magnetization in a first radial direction 17 of said rotor 5.

 Advantageously, this magnet 16 is surrounded on either side, on each side, by at least one magnet 18 and 19 which comprises a parallel magnetization in a direction of transverse magnetization 20 with respect to said first radial direction 17, c ' that is to say making an angle 21 between -20 ° and + 20 ° with respect to a direction perpendicular to said first radial direction 17.

 Advantageously, this angle 21 of the magnets 18 and 19 is 45 °.

 Preferably, the transverse magnetization direction 20 of the magnets 18 and 19 is perpendicular to the first radial direction 17 of the magnet 16.

In this respect, it is the combination of the power supply of the stator 11 and the arrangement of the three magnets 16, 18 and 19 which makes it possible to create a variable and intense field greater than 1.1 Tesla and of rectangular shape. , still visible in Figure 7. More particularly, and as can be seen in FIG. 8, the concentration of flux, due to the particular assembly of the permanent magnets 15, makes it possible to locally maximize the induction by concentrating the field lines in a large zone of the first air gap 7A, zone maximum induction 22, while deflecting the flow out of the first air gap 7A, to obtain at the same time in another area of the first air gap 7A a zero induction zone 23.

 Advantageously, a large variation Δ of the maximum magnetic field B is created at a point of the exchanger 4 (or the first gap 7A) of the rotating machine 1.

 According to a preferred embodiment of the invention, the magnet 16 comprising a parallel magnetization in a first radial direction 17 of said rotor 5 is constituted by the juxtaposition of at least:

 a first magnet 24 of substantially hexagonal section, visible in Figure 9, in a plane perpendicular to said axis of rotation 2.

 a second magnet 26 of trapezoidal section, visible in FIG. 10, in a plane perpendicular to said axis of rotation 2.

 Advantageously, the first magnet 24 comprises a first face 27 extending in the vicinity of said first gap 7A parallel to the tangent 28 to the first outer surface of revolution 9 of said rotor 5 in the vicinity of said first face 27, and comprises a second face 29 substantially parallel to said first face 27 which extends in the vicinity of said second gap 7B substantially parallel to the tangent 30 to the second internal surface 10 of said rotor 5.

 In this respect, it will be observed that this second face 29 may have a radius of curvature slightly greater than the second internal surface of revolution 10 of the rotor 5.

It comprises two first external oblique faces 31 and 32 on the side of said first air gap 7A and two seconds internal oblique faces 33 and 34 on the side of said second gap 7B.

 Preferably, the first magnet 24 comprises a parallel magnetization according to the first radial direction 17 of said rotor 5.

 Advantageously and analogously to the first magnet 24, the second magnet 26 is of parallel magnetization in the same first radial direction 17 of said rotor 5 and in the same direction as the first magnet 24 to which the second magnet 26 is joined by the shorter of its parallel faces 35.

 More particularly, the shortest of its parallel faces 35 extends between the first magnet 24 and the first gap 7A in the vicinity of which extends the longest of its parallel faces 36. Moreover each oblique face 37 and 38 of the second magnet 26 constituting with one of the first oblique faces 31 or 32 of the first magnet 24 a housing 39.

 According to another preferred embodiment of the invention, the magnets 18 and 19, which comprise a parallel magnetization in a direction of transverse magnetization 20 with respect to said first radial direction 17, are constituted by at least:

 a third magnet of rectangular section 40, visible in Figure 11, in a plane perpendicular to said axis of rotation 2, extending in an oblique longitudinal direction 41 relative to a second radial direction 42 of said rotor 5;

 a fourth magnet of rectangular section 43, still visible in FIG. 11, in a plane perpendicular to said axis of rotation 2, extending in an oblique longitudinal direction 44 with respect to a third radial direction 45 of the rotor 5 and symmetrical to that of the third magnet 40 rectangular with respect to the first radial direction 17.

Advantageously, the third magnet 40 is plated at a first end 46 on one of its small faces 47 against said second magnet 26 and against said first magnet 24 by one of its long faces 48 in one of said housings 39. is of parallel magnetization and forms an angle of about 45 ° +/- 20 ° with the longitudinal direction 41 and in a direction perpendicular 49 to said first radial direction 17 of the rotor 5;

 Preferably, the fourth magnet 43 is, in turn, plated at a first end 50 against said first magnet 24 and said second magnet 26 in the other of said housings 39. It is of parallel magnetization and forms an angle of about 45 ° +/- 20 ° with the longitudinal direction 44 and in the same direction 49 as said third magnet 40 but in the opposite direction.

 Advantageously and according to a preferred embodiment of the invention, the third magnet 40 of rectangular section extends in a perpendicular longitudinal direction 51 to the second radial direction 42 of said rotor 5.

 In this regard, it will be observed that the fourth rectangular section magnet 43 extends preferentially in a perpendicular longitudinal direction 52 to the third radial direction 45 of said rotor 5.

 In an advantageous manner and as can be seen in FIG. 13, the third rectangular magnet 40 and the fourth rectangular magnet 40 each comprise a second end 53 and 54 opposite to said first end 46 and 50 respectively. This second end 53 and 54 is preferably designed adapted to cooperate with the second ends 53A and 54A that respectively comprise a third 40A and a fourth 43A rectangular magnet of another contiguous pole and identical direction of magnetization.

 Substantially, the rotary machine 1 is thus composed of several pairs of adjacent rotor poles each comprising this particular arrangement of magnets 15 making it possible to obtain a variable and intense field B at a point of the exchanger 4.

Moreover, and as can be seen in FIG. 6, the rotary machine 1 comprises an alternation of poles, the first having a centrifugal radial direction magnetization the first hexagonal magnet 24 and the second trapezoidal magnet 26, and a magnetization direction of the third rectangular magnet 40 and the fourth rectangular magnet 43 towards its first radial direction 17.

 The second pole, meanwhile, contiguous with the first pole preferably comprises a magnetization of centripetal radial direction at the first hexagonal magnet 24 and the second trapezoidal magnet 26, and a direction of magnetization of the third rectangular magnet 40 and the fourth rectangular magnet 43 away from its first radial direction 17.

 According to a particular embodiment of the invention, the rotating machine 1 comprises, at the level of the stator 11, heat exchange means connected to the exchanger 4, for cooling the stator poles.

 Concretely, a part of the frigories created in the exchanger 4 is derived to the stator 11 to improve its performance, and thus creates a self-cooling effect.

 In this regard, it will be observed that the rotating machine 1 also comprises, preferably, regulation means adapted, when the temperature of the stator 11 decreases, driving current supply means of the stator poles to increase the current density and consequently to increase the induction. The cooling of the stator 11 by the utilization circuit of the exchanger 4 makes it possible to maximize the induction by minimizing the volume of the rotary machine 1.

 Moreover, this temperature regulation in the stator 11 makes it possible, on the one hand, to regulate the temperature of the surrounding materials so that the magnetocaloric material is always close to its Curie temperature, that is to say the temperature at which the material loses its spontaneous magnetization, and on the other hand to increase the performance of the rotating machine 1.

The invention also relates to a high-power self-cooling synchronous motor greater than a few tens of kW comprising a rotating machine 1 as described above.

 Moreover, one of the recurring problems in operating large synchronous motors is their cooling. By the construction of an engine according to the invention, it is now possible to integrate into the machine an autonomous and efficient cooling circuit based on the performance of magnetocaloric materials.

 The invention also relates to the use of the rotary machine 1 for a magnetocaloric exchange, the exchanger 4 being a magnetocaloric exchanger 4 comprising a magnetocaloric effect material, especially gadolinium.

 According to one embodiment of the invention, the rotating machine 1 comprises a stator 11 has an outer diameter of 83.5 mm and a depth of the order of 89 mm. It comprises twelve teeth 14 having a height of 25.75 mm and a notch surface of 344 mm. These teeth 14 have a dental coil comprising 35 turns.

 At the periphery of this stator 11 the rotating machine comprises a rotor 5 having an outside diameter of 166.7 mm and a depth of 89 mm. Inside this rotor 5 the rotating machine 1 comprises a magnet assembly 15 composed for a pole of a hexagonal magnet 24 71 mm long by 33 mm wide and 89 mm deep, a trapezoidal magnet 26 length 42 mm, width 9 mm and depth 89 mm and two rectangular magnets 40 and 43 length 42 mm, width 11 mm and depth 89 mm.

 Around this rotor 5 the rotating machine 1 further comprises an exchanger having an outer diameter of about 185 mm and depth 89 mm.

 All of these elements are protected by a steel cylinder head 3 having an external diameter of 220 mm and a depth of 89 mm.

It is well understood, in view of this dimensioning, that the rotary machine 1 as described above has a space advantageously reduced while offering great power.

Claims

1. Rotating machine (1), about an axis of rotation (2) inside a cylinder head (3) peripheral, producing a variable magnetic field and maximum intensity greater than a Tesla, for performing a variation of said field at a point of an exchanger (4) located at said yoke (3), according to a substantially square diagram as a function of time, said machine comprising, movable in rotation about said axis of rotation (2) within a bore (6) that includes said yoke (3) or said exchanger (4) and separated from said bore by a first air gap (7A), a rotor (5) having a first outer surface of revolution (9) ) about said axis of rotation (2), said rotor (5) having a first even number (n) of poles constituted by an assembly of flow concentrating means (8), and said yoke (3) being adapted able to loop back magnetic field lines generated by said rotor (5), characterized in that the said rotor (5) has a second inner surface of revolution (10) about said axis of rotation (2), and said rotary machine (1) has inside said rotor (5) and separated from said second surface internal revolution (10) by a second air gap (7B), a stator (11) designed to create a magnetic field and designed able to capture a portion of the magnetic flux emanating from said rotor (5) to put it in rotational movement under the effect of an electromagnetic torque, said stator (11) itself having a second even number (N) of stator poles.  2. Rotating machine (1) according to claim 1, characterized in that said exchanger (4) is integrated in said yoke (3) which comprises said bore (6), in the vicinity of said first gap (7A). 3. rotating machine (1) according to claim 1, characterized in that said exchanger (4) is interposed between said yoke (3) and said first air gap (7A), and said exchanger (4) comprises said bore (6). ). 4. rotating machine (1) according to one of the preceding claims, characterized in that said exchanger (4) comprises a magnetocaloric effect material, including gadolinium, designed capable of exchanging energy with a heat transfer fluid under the effect of magnetic field variation B.  5. Rotating machine (1) according to the preceding claim, characterized in that said flux concentration means (8) comprise permanent magnet assemblies (15).  6. Rotating machine (1) according to claim 5, characterized in that for each pole of said rotor (5) extending between said first gap (7A) and said second gap (7B) is formed said permanent magnet assembly (15) comprising, developing substantially prismatically or helically relative to said axis of rotation (2), at least one magnet (16) having a parallel magnetization in a first radial direction (17) of said rotor (5), which magnet (16) is surrounded on either side by at least one magnet (18, 19) which has a parallel magnetization in a transverse magnetization direction (20) with respect to said first radial direction (17). ), that is to say making an angle (21) between -20 ° and + 20 ° with respect to a direction perpendicular to said first radial direction (17).  7. Rotating machine (1) according to claim 6, characterized in that said transverse direction (20) is perpendicular to said first radial direction (21).  8. rotating machine (1) according to one of claims 6 or 7, characterized in that said magnet (16) having a parallel magnetization in a first radial direction (17) of said rotor (5) is constituted by the juxtaposition of at least : a first substantially hexagonal section magnet (24) in a plane perpendicular to said axis of rotation (2), said magnet (24) having a first face (27) extending in the vicinity of said first gap (7A) parallel to the tangent (28) to the first outer surface of revolution (9) of said rotor (5) in the vicinity of said first face (27), and having a second face (29) substantially parallel to said first face (27) extending in the vicinity of said second air gap (7B) substantially parallel to the tangent (30) to the second internal surface of revolution (10) of said rotor (5), said first magnet (24) having a parallel magnetization in a first radial direction (17) of said rotor (5), said first magnet (24) further comprising two first external oblique faces (31, 32) on the side of said first gap (7A) and two second inner oblique faces (33,34) on the side of said second gap (7B);  a second magnet of trapezoidal section (26) in a plane perpendicular to said axis of rotation (2), of parallel magnetization along the same first radial direction (17) of said rotor (5) and in the same direction as said first magnet ( 24) to which said second magnet (26) is joined by the shortest of its parallel faces (35), and which extends between said first magnet (24) and said first gap (7A) in the vicinity of which extends the most long of its faces (36) parallel, each oblique face (37, 38) of said second magnet (26) constituting with one of said first oblique faces (31, 32) of said first magnet (24) a housing (39).  9. Rotating machine (1) according to one of the claims 8, characterized in that said magnets (18, 19) which comprise a parallel magnetization in a direction of transverse magnetization (20) with respect to said first radial direction (17) are constituted by at least: a third magnet of rectangular section (40) in a plane perpendicular to said axis of rotation (2), extending in an oblique longitudinal direction (41) with respect to a second radial direction (42) of said rotor (5), plated at a first end (46) on one of its small faces (47) against said second magnet (26) and against said first magnet (24) by one of its long faces (48) in one of said housing (39), and of parallel magnetization and at an angle of about 45 ° +/- 20 ° with said longitudinal direction (41) and in a direction perpendicular (49) to said first radial direction of the rotor (17);  a fourth magnet of rectangular section (43) in a plane perpendicular to said axis of rotation (2), extending in an oblique longitudinal direction (44) with respect to a third radial direction (45) of said rotor (5) and symmetrical to that said third rectangular magnet (40) with respect to said first radial direction (17), plated at one end (50) against said first magnet (24) and said second magnet (26) in the other said housing (39); ), and parallel magnetization and at an angle of about 45 ° +/- 20 ° with said longitudinal direction (44) and in the same direction as said third rectangular magnet (40) but in opposite directions.  10. Rotating machine (1) according to claim 9, characterized in that said third rectangular magnet (40) and said fourth rectangular magnet (43) each comprise a second end (53, 54) opposite said first end (46, 50) and designed to cooperate with the second ends (53A, 54A) that respectively comprise a third (40A) and a fourth (43A) rectangular magnet of another contiguous pole and identical direction of magnetization.  11. Rotating machine (1) according to one of claims 9 or 10, characterized in that said third rectangular section of a magnet (40) extends in a longitudinal direction perpendicular (51) to said second radial direction (42). ) of said rotor (5), and said fourth rectangular section magnet (43) extends in a longitudinal direction perpendicular (52) to said third radial direction (45) of said rotor (5). 12. Rotating machine (1) according to one of claims 6 to 11, characterized in that it comprises an alternating poles, one having a magnetization of meaning centrifugal radial at the first hexagonal magnet (24) and the second trapezoidal magnet (26), and a magnetization direction of said third rectangular magnet (40) and said fourth rectangular magnet (43) towards said first radial direction (17) and the other contiguous pole having a centripetal radial direction magnetization at the first hexagonal magnet (24) and the second trapezoidal magnet (26), and a magnetization direction of said third rectangular magnet (40) and said fourth rectangular magnet. (43) away from said first radial direction (17).  13. Rotating machine (1) according to one of the preceding claims, characterized in that it comprises means for regulating speed of rotation by regulating the current delivered to windings that includes said stator (11), according to information receivers Hall effect sensors arranged on several teeth (14) that comprises said stator (11).  14. Rotating machine according to one of the preceding claims, characterized in that it comprises, at said stator (11), heat exchange means connected to said exchanger (4), for cooling said stator poles, and it comprises regulating means designed apt, when the temperature of said stator (11) decreases, to drive current supply means of said stator poles to increase the current density and consequently increase the induction.  15. Self-cooling synchronous motor of high power greater than a few tens of kW comprising a rotary machine (1) according to claims 4 and 14.  16. Use of the rotary machine (1) according to one of the preceding claims for magnetocaloric exchange, said exchanger (4) being a magnetocaloric exchanger (4) comprising a material magnetocaloric effect, including gadolinium.