JP2002526014A - Apparatus and method - Google Patents

Abstract

(57) [Summary] A rotary electric machine having a stator (2) and a rotor (1). The stator has a core made of a magnetizable material and a winding (8). The rotor has one degree of freedom to rotate with respect to the stator. The stator has a cup-shaped hollow (9) surrounding the rotor. The hollow has a rotationally symmetrical wall with a partially arched line rotated about an axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

【Technical field】

The present invention relates to a rotating electrical machine having a static part or stator and a rotating part or rotor rotatably supported by a journal with respect to the stator. More specifically, the present invention relates to a rotating electric device having a stator whose inner surface is different from a cylindrical shape. The rotating electrical device according to the present invention, for both high voltage and low voltage,
It is manufactured for a plurality of power ranges. The invention is preferably used in power networks, especially for high voltage and high power. As used herein, the term rotating electrical equipment refers to electrical equipment having a rotating part that converts electrical energy into mechanical energy or vice versa. Thus, rotating electrical equipment can be either a motor or a generator.

[0002]

[Background Art]

Most currently known rotating electrical machines have a cylindrical rotor that rotates within a stator having a cylindrical hollow. In order to obtain a large torque, the diameter of the rotor is increased, and in order to increase the acceleration, a rotor having a small diameter and a long shaft is used. The rotational speed and the material strength of the outer member of the rotor are generally factors that determine the outer shape of the rotor. The first reason for the cylindrical shape of the stator is that it is much easier to manufacture. The fact that the rotor rotates only means that a rotationally symmetric shape is allowed inside the stator. Similarly, it must have a shaft that is housed in the stator and only contacts the outside. The air gap between the interior of the stator and the cylinder contained therein is the air gap.

[0003] The shape of ordinary rotating electrical equipment is determined for historical reasons.
The rotor and the stator are usually manufactured separately. To subsequently combine the two parts to ensure a uniform air gap, there are only two shapes available: cylinders or cones. The conical design has a number of disadvantages compared to the cylindrical design, and the only commercial product is the brake motor. The most commonly used type of rotating electrical equipment at present is thus cylindrical. With current winding technology, coil windings will be installed in slots in the stator or rotor. When manufacturing a motor for high voltage, a coil is first wound around a fixed member, and an insulator is provided thereon. Thereafter, the coil is often autoclaved to discharge air bubbles and cure the insulator. The coil thus "completed" is pushed into the slot and secured with a wedge. Finally, the ends of the coils are connected to each other to complete the winding.

[0004] According to established manufacturing techniques for large rotating electrical machines, the rotor core, as well as the stator core, are often constructed of laminated steel plates. Laminates oriented in a magnetic sense are axially superposed to reduce eddy current losses.
Stacking stators for such rotating electrical equipment means overlapping the stators at the edges. Each layer is composed of a stamped metal sheet and forms a part of a cylindrical shape and constitutes an axial layer of a hollow cylinder. The seat has a punched-out portion that becomes a slot for accommodating the winding when the stator is completed.
Between the slots are formed comb teeth having a pointed point, which constitute the inner surface of the stator.

However, when the Maxwell's equation is evaluated, it is understood that the induction force can be more effectively used by making the rotor and the stator non-cylindrical. A more efficient rotary electric machine is obtained by the structure in which the short end of the rotor is rounded and the stator covers the rounded portion of the rotor. According to the above description, it is understood that this is a completely new approach and involves a completely new method of manufacturing rotary electric equipment.

[0006] In specialized books and some patent documents, what is called a so-called "spherical motor" is described. This expression implies that it is about a motor and that the rotor is spherical and rotates around a shaft. However, 1
It is the drive of an industrial robot that requires three-dimensional movement around one point. One example of such a device is described in U.S. Pat. No. 5,410,232. In the device shown there, the axis fixed to the rotor is not essentially a rotating axis, but rather moves to "point" in different directions under control. Another example of this type of device is that described in U.S. Pat. No. 5,413,010. The role of the motor disclosed therein is not for rotating basically, but for a device for turning the operating arm in various directions. None of the examples are, therefore, related to rotating electrical equipment for rotating a rotor with one degree of freedom, but to a motor for rotating a shaft around a common point under control.

[0007] Other examples of so-called "spherical motors" are described in US Patent Nos. 4,739,241 and 4,661,737. These publications disclose motors which are known per se, having a rotating shaft fixed to the suspension. The suspension allows the axis of rotation to be oriented in various directions around the center under certain control.

[0008] An example of a rotary motor whose rotor is not cylindrical is a pump motor. In this application, the motor is often spherical. One half of the sphere contains an impeller that imparts kinetic energy to the liquid flowing through it. The other half is a rotor that also rotates by receiving magnetic force from a hemispherical stator. The magnetic fields of the rotor and stator are unbalanced and will apply an undesired axial force to the axial bearing. Normally, such pump motors do not rotate around a static shaft, and the rotor is journaled by a ball, which can eliminate shaft bearings that require sealing and reduce Can shake her head around the center to some extent. Examples of this type of pump motor are described, for example, in U.S. Pat. Nos. 4,580,335 and 4,352,646.

A rotating electric device having a rotor constituted by a thick portion cut out from a sphere is described in “Design of a Spherical Motor” by ER Laithwaite, “Electrical Times”.
, On June 9, 1960. The motor discussed in that document is
An air gap of uniform thickness is provided around the rotor. The stator is a collection of radial plate members having punched pockets for receiving stator windings. The stator is rotatable about an axis perpendicular to the shaft of the rotor, with a portion of the stator bent outwardly of the rotor. The windings of the stator are at an angle to a plane transverse to said axis. When you rotate the stator,
The electromagnetic induction force is reduced, and the windings of the rotor and the stator become angled with each other. The purpose of the device shown here is to control speed and torque by rotating the stator.

US Pat. No. 5,204,570 discloses a rotating electrical machine having a non-cylindrical rotor. The purpose of the device is to produce a small motor under conditions where reducing the overall volume is a primary requirement. It describes that the device is used as a drive motor for a fan, a disk or a tape recorder. According to the description, the motor is inexpensive and surprisingly efficient, even if it is small. The apparatus comprises a spheroidal rotor having one or more permanent magnets. The stator has a spirally wound coil whose axis intersects the motor shaft. The coil has no iron core and is slightly curved. The gazette states that
It is stated that it is preferable to use an air-core coil for the stator in terms of weight. Laminated cores are not only expensive due to expensive equipment, but also involve losses due to eddy currents.

To collect a magnetic field outside the stator, a dome-shaped shell made of a ferromagnetic material is connected to the rotor. The fact that the dome rotates with the rotor means that no eddy current losses occur. However, in practice, such motors have the disadvantage of rotating the outer wall.

[0012] At least when the output is large, the stator windings generate large heat and need to be cooled. In the case of air-core coils, heat can only be removed by the surrounding air. For efficient cooling, the surrounding air must be circulated so that the cool air goes around the coil permanently. In this regard, the outer dome obstructs the surrounding air circulation. Therefore, the cooling efficiency becomes extremely poor,
The insulation material of the windings melts, creating the danger of a short circuit. Efficient cooling usually requires a heating medium that makes thermal contact with the windings to effectively remove the heat by the coolant. Metal is one such heat carrier.

[0013]

[Summary of the Invention]

SUMMARY OF THE INVENTION It is an object of the present invention to propose the production of a rotating electrical machine using electromagnetic induction between a rotor and a stator in a more effective way than in the prior art. Rotary electrical equipment, such as motors or generators, are cost effective and can produce high and low voltage equipment over a wide output range. Compared with a conventional device of the same output, the device according to the invention can save a great deal on the stator and rotor core and also on the winding material. The device according to the invention can be manufactured much more efficiently than a conventional device of the same size. The device according to the invention can remove heat generated in the device very efficiently.

The rotary electric machine can be manufactured for high output as well as for low output.
Applications targeted by the device include use in high pressure areas for hydro or turbo generators that are directly connected to a high voltage network of 36 kV or higher. In this type of application, the device is manufactured for an output of 10 kW or more. Similarly, it is possible to manufacture devices to be connected to the power grid. For low pressure,
Many applications are envisaged for using the power saving device according to the invention as a motor or a generator. Thus, the device according to the invention can be used as a mobile generator driven by an internal combustion engine. The device according to the present invention can also be used as a drive source for a mobile transport device. Moving and transporting here needs to be understood in a broad sense. The term “mobile conveyance” includes a land vehicle moving on a road surface or a track, and a device moving in the air or underwater. Other applications included in the low power applications according to the present invention are power sources in home appliances such as refrigerators, freezers, vacuum cleaners, cooking appliances and the like.

[0015] Each of the above objects is achieved by a rotating electric machine having the features described in the independent claims 1, 17 and 19 and the features described in the independent claims 12 and 16. And a method having the above. The features of the dependent claims describe preferred embodiments.

In the following part of the description, a rotating electrical machine, referred to as a motor, a generator or a device, comprises a stator having a rotationally symmetrical core made of a magnetizable material, at least part of its inner surface being cup-shaped. Have. By magnetizable material is meant a material having a relative permeability greater than one. The inner wall surface of the stator therefore has a hollow with a curved shape. The rate of change of the curve is continuous and the rate of change is non-zero at least at the ends. Similarly, the rotor may not have a cylindrical shape but have a shape similar to the inner wall surface of the stator, and a substantially constant air gap may be formed between the rotor and the stator. In the apparatus according to the present invention, it is essential that the magnetic field spreads three-dimensionally toward the center of the rotor. Such a dynamic magnetic field traverses the windings of the stator approximately at right angles and surrounds the rotor, or at least partially surrounds the rotor in a cup shape.

While the dynamic field of a conventional cylindrical motor is wedge-shaped, the field of the motor according to the invention is conical or pyramid-shaped. The cup-shaped magnetic field amplifies the electromagnetic induction force of the stator and the rotor. A magnetic field according to the present invention can be represented by a field line vector having a component parallel to the axis of the rotor and pointing to the center of the rotor. When the magnetic fields are balanced, the sum of the axial components is zero.
The most efficient embodiment would be an apparatus with a stator having a spherical inner wall and a spherical rotor rotating therein. However, since it is difficult to wind the winding of the stator near the shaft of the device, it has been suggested that a rotating shape other than a sphere is more preferable.

The target shape of both the rotor and the stator is a so-called spheroid. A spheroid is a shape obtained by rotating an ellipse around an axis of symmetry. Therefore, this shape can take both a flat and flat shape and an elongated shape of an elongated sphere. Since the ellipse includes a circle, the spheroid includes a sphere. The common rotation shape, however, is not necessarily limited to a spheroid, and many other rotation shapes are possible. The present invention also includes a cylinder having a spheroid added to both ends. In some applications, the shape is determined from practical aspects of the stator windings.

The device according to the invention can be provided with windings of various different shapes on both the rotor and the stator. In the present invention, the winding method used in the conventional device can be used. A squirrel cage type winding wire can be used for the rotor, and the stator and the rotor are both wrapped (lap wind).
ing) and wave windings can be used. The device may be provided with windings for connection to a power grid. This is especially true for alternating currents.
This involves applying single phase or multiple phase windings as used in conventional devices. In the above sense, the conventional device means a device having a cylindrical rotor and a stator having a cylindrical inner wall surface.

As in the conventional device, the rotor and / or the stator of the device according to the invention are provided with slots for receiving windings. In the conventional device, it is natural that the winding slot is straight. In the case of the device according to the invention, the slots are curved, so that the usual winding techniques cannot be applied directly. It is therefore not appropriate to first form the winding by winding it around the object to be fixed and then insert it into the slot. In the case of the device according to the invention, the winding must be wound "with respect to the actual machine". For this purpose, the winding is preferably a cable. By cable is meant an electrical conductor with flexible insulation, possibly with multiple conductor strands.

To connect directly to the high-voltage grid, the device according to the invention uses high-voltage cables as windings. By doing so, power of 10 MW or more can be obtained. Such cables usually have a uniform layer of semiconductor around the conductor, which may be divided into bundles of fine wires. The semiconductor layer is for dispersing the electric field so that the electric field concentration that causes flashover does not occur. This type of cable further has a semiconductor layer around the insulating layer to confine the electric field inside the cable. Normally, the external semiconductor layer is grounded. Suitable cables and winding methods for use at high voltages are described in International Application WO 97/45919.

In the case of a conventional device having a cylindrical rotor rotating in a cylindrical stator, the end walls are ineffective surfaces. There is no effective magnetic field generated, but instead leakage that impairs effectiveness. Connecting the coils by the conventional winding technique requires a large volume at the end of the stator. The fact that the coil ends require space means that the bearings for the rotor shaft must be provided at a distance from the center of the rotor. This means that the risk of the rotor being out of balance increases, and it is necessary to increase the size of the bearing. In other words, it can be seen that the end walls of the conventional device reduce the efficiency and hinder efficient use of the volume of the entire device. It is considered effective to make the end wall of the rotor round and make the stator cup-shaped. Thus, the efficiency of the device can be improved by surrounding the entire rotor with the concentrated magnetic field.

It will be explained that the rotary electric machine according to the present invention has several advantages compared to the conventional device having a cylindrical rotor and a corresponding stator. Despite the same power, the weight of the device according to the invention is reduced by 30% due to the large volume of the rotor of the conventional device. If the device according to the invention is of the same weight as a conventional device, the output can be increased by 50%.

If a conductor loop surrounds a time-varying magnetic flux, a voltage or electromotive force is generated in the loop. The induced voltage is the product of the number of turns in the loop and the rate of change of magnetic flux over time. The magnetic flux depends on the product of the magnetic field and, for example, the area of the region surrounded by the windings of the stator. Since the magnetic field depends on the material, it can be seen that only the area is variable. When the area is optimized according to the conditions, a constant volume is formed by the rotation of the loop, so that the area of a circle or a sphere can be obtained. This implies that the rotor must be spherical and the inner surface of the stator must be spherical.

With conventional devices, the end of the coil has been a problem. In the device according to the invention, virtually no ends of the coil are present. Therefore, the losses due to the edges of the device are much smaller than the edge losses in conventional devices.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in more detail with reference to preferred embodiments and the accompanying drawings.

The electric rotating machine shown in FIG. 1 includes a rotor 1 and a stator 2. The rotor has one rotational degree of freedom with respect to the stator. The stator consists, for example, of a laminate that is magnetically oriented with respect to the core surrounding the rotor. The stator has the same number of status lots 4 as the plurality of comb teeth 3. A plurality of insulated conductors 5, which may have a plurality of conductor strands, are housed in the status lot. In the example shown in the figure, the cable is wound, and the device shown is for high voltage. The conductor has one or more main windings as a whole. At the furthest point in the radial direction, a plurality of small and insulated conductors 6 are provided, which in the example shown are connected to a plurality of voltages, for the additional power or voltage of a so-called multi-voltage device. It is a winding of.

FIG. 2 is a diagram showing a basic configuration of a rotating electric device according to the present invention. The rotor 1 is fixed to a rotor shaft 7 and rotates around it. The rotor is surrounded by a stator 2, which is made of a magnetic material, for example iron, which may be magnetically oriented. The stator has an internal gap 9 surrounding the rotor 1, and the surface thereof corresponds to the inner surface of the stator. In the example shown in the figure, the gap is spherical. The outside of the stator is spheroidal. In the example shown, the surface is in the form of a spheroid with the ellipse rotated about a minor axis, which is the same axis of symmetry as the axis of the rotor. However, the outer shape of the stator can take any shape. The rotor has a solid shape during rotation, and in the example shown in the figure, has a spheroidal shape. In the example shown in the figure, both the stator and the rotor have a rotating shape, and their axes overlap. However, the rotation axes may have a positional relationship intersecting with each other.

The figure shows four stator windings 8 penetrating the stator core. Three windings exit the stator core at the rotor end, one is housed in the stator. The stator windings are woven into slots in the stator core. Comparing the cross section of the stator taken in a plane perpendicular to the axis of the rotor, it can be seen that the diameter is greatest in the vertical plane in the center of the rotor axis. The diameter of the cross section decreases as it approaches the end of the stator. In the example shown, the cross-sectional area of the stator also decreases as it goes to the ends. However, the area of the winding is constant throughout the cross-section, so the ratio of the core area decreases as it approaches the end. Thus, it can be seen that at a distance from the central vertical plane, there is no core area between the windings. At this distance from the central vertical plane, the windings can be accommodated in the same slot or wound so as to cross each other. At a position further from the plane of symmetry, only the area for winding remains, so that the winding extends off the stator core into the air. On the opposite side of the rotor shaft, the windings are housed in the stator core as described above. To describe the winding technique in more detail, the winding method is likened to winding a wire around a ball while rotating it with one degree of freedom. This means that the winding is also wound in a direction transverse to the axis of the rotor.

FIG. 3 shows a stator element 10 cut from a stator, wherein the stator element consists of a body defined by two plane parts which intersect at the same line with the axis of symmetry of the hollow space. To better describe the appearance of the body, it can be compared to, for example, a piece of melon. The stator element is sandwiched between an inner cup-shaped surface 11 which is the same as the hollow 9 and a bulging outer surface 12 (hidden). In the axial direction, the body is sandwiched between a planar second side 14 (hidden) as well as a planar first side 13. The long axis of the stator element coincides with the rotor axis. In order to ensure space for the rotor shaft, a first cup-shaped chamfer 15 and a second cup-shaped chamfer 16 are provided between the first side and the second side in the stator element. ing. The figure further shows contour lines of a part 17 incorporated in the main body, which will be described in detail with reference to FIG.

FIG. 4 shows, for example, a part 17 of a core cut out of a stator element of a low-voltage device. For clarity, it is assumed that the clipped portion has been clipped from FIG. 3 as shown by the dashed line. That portion of the core is contoured by four planes that intersect at the same point such that the portion of the core is shaped like a truncated pyramid. The four planes are merely imaginary surfaces of the cut core portion, and are for showing a three-dimensional shape. A continuous passage 18 extends through the portion of the core and can accommodate a winding (not shown). The side of the hole is continuous with the opening 19, and the opening is connected to the first comb teeth 20 and the second
Is further divided into a comb tooth 21 and a back portion 25 thereafter. The interior of the core body extends to a cup-shaped first comb tooth surface 22 and a second comb tooth surface 23, both of which are cup-shaped, and the outside of the back portion extends to a bulging envelope surface 24 (hidden).

To drive the loop through hole 18, a magnetic field is generated through a portion of the core. From a rotor (not shown) located immediately before the comb teeth, a magnetic field is directed vertically to the cup-shaped first comb tooth surface 22. In the part of the core, the magnetic field extends axially along the comb teeth, then tangentially on the back, and through the outer part of the stator. When the magnetic field reaches the cup-shaped second comb tooth surface, the magnetic field exits vertically from the second comb tooth surface to the rotor, where it closes.

The area of magnetizable material through which the magnetic field penetrates is the same in each section. In the three-dimensionally bent stator corresponding to the core portion shown in FIG. 4, the distance from the edge to the hole is compensated by the large width of the rear portion. The section shown by the broken line in the figure illustrates this fact. The figures show that the first comb tooth surface 22 is as large as the first section 26 at the location where the width of the passage 18 is maximized. Finally, it is shown that this area is also the same as the second section 27 located at the back and facing the first comb tooth surface. Accordingly, it has been shown that a three-dimensional curved surface saves material, and in particular, saves material in the rear part of the stator and can reduce the size of the stator.

The rotor of the device described above can take many different forms. FIG. 5 shows three examples of the rotor used in the apparatus. FIG. 5a shows a ball-shaped rotor, and FIG. 5c shows a spheroidal rotor. In the illustrated example, the spheroid is vertically long, that is, elongated. FIG. 5b shows a combined shape in which the central portion is cylindrical and the long end is semi-spheroidal.

A cooling channel (not shown) for coolant may be provided in the stator core to remove heat generated by the device. The device shown in the figure is obtained by winding a high-voltage cable having a plurality of stranded wires. This type of cable is completely insulated and thus contains a complete voltage potential inside the insulator. This arrangement is advantageous, for example, when cooling the device, since a stator is provided.
In this way, the coolant is also maintained at ground potential. Another great advantage of the insulated cable is that the windings can be wound freely to intersect each other and can also be wound so that they touch each other at the end of the device.

The present invention is not limited to the illustrated embodiment. The shapes of the rotor and the stator can be varied in a very wide range. The common feature of these is that the stator surrounds the rotor in a cup shape so that a three-dimensional magnetic field surrounds the rotor. Furthermore, the invention does not require that the windings be accommodated in slots in the stator. The winding may thus be a so-called air gap winding. The windings of the device of the invention may be wound in the same direction as the rotor or stator shaft. A part of the winding can be wound in a free pattern along the curved stator, and may be a straight slot or a slot intersecting the axis of the rotor. Also, the rotor and stator shafts need not coincide, and the structure where the shafts intersect is also part of the present invention.

The motor according to the present invention may have a permanent magnet on the rotor or the stator.

[Brief description of the drawings]

FIG. 1 shows a half section of a rotating electrical machine according to the invention.

FIG. 2 shows an axial section through the basic structure of one embodiment of the device according to the invention.

FIG. 3 is a cutaway view of a stator member of the device according to the present invention.

FIG. 4 is a cutaway view of a stator member.

FIG. 5 shows three different rotor shapes (a, b) of a rotating electrical machine according to the invention.
, C).

[Procedural Amendment] Submission of translation of Article 34 Amendment of the Patent Cooperation Treaty

[Submission date] December 14, 2000 (2000.14)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) // H02K 3/40 H02K 3/40 (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, I, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV , MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZA, ZWF terms (reference) CC01 CC02 CC05 CC13 PB03 5H619 AA01 AA03 AA04 AA05 BB01 BB02 BB06 PP01 PP04 PP14

Claims (20)

[Claims] An air gap is formed between a stator (2) having a core made of a magnetizable material and a winding (8) and a stator (2) having one degree of freedom to rotate with respect to the stator. A rotary electric machine comprising a rotor (1) having a curved hollow (9) entirely surrounding the rotor (1). 2. The rotary electric machine according to claim 1, wherein the hollow has a shape of a rotating body whose diameter gradually decreases at least at an end. 3. The rotary electric machine according to claim 1, wherein the hollow has a spheroidal shape. 4. The rotary electric machine according to claim 1, wherein the hollow (9) is spherical. 5. The air gap according to claim 1, wherein a thickness of the air gap in a direction perpendicular to a surface defining the hollow increases toward an end of the stator.
A rotary electric device according to any one of the above. 6. The rotary electric device according to claim 1, wherein a thickness of the air gap in a direction orthogonal to a surface defining the hollow is constant. 7. A method for directly connecting a rotating electrical device to a power network according to claim 1. 8. A method of using the rotary electric device according to claim 1 directly connected to a high-voltage power network of 36 kV or more. 9. A method of using the rotating electric device according to claim 1 as a generator of a transfer device driven by an internal combustion engine. 10. A method of using the transfer device for rotating electric equipment according to claim 1 as a main power source. 11. A method of using the rotary electric device according to any one of claims 1 to 6 as a main power source of a home electric appliance. 12. An air gap is formed between a stator (2) having a core made of a magnetizable material and a winding (8) and a stator (2) having one degree of freedom to rotate with respect to the stator. A method for manufacturing a rotating electric machine comprising a rotor (1) having an arc-shaped hollow (9) in a stator (2), wherein the rotor (1) is entirely surrounded by the stator. Production method. 13. Method according to claim 12, characterized in that the hollow (9) is of a symmetrical shape with a decreasing diameter at least at the ends. 14. The method according to claim 12, wherein the hollow (9) has a spheroidal shape. 15. The method according to claim 12, wherein the hollow (9) is spherical. 16. Production of a rotary electric machine comprising a stator (2) having a core made of a magnetizable material and a winding (8), and a rotor (1) having one degree of freedom rotating with respect to the stator. Manufacturing, characterized in that the rotor (1) has a solid shape during rotation, the stator (2) is provided to surround the rotor by an arcuate hollow, and then the stator is provided with windings (8). Method. 17. A stator (2) having a core made of a magnetizable material and a winding (8), and a rotor (1) rotating about an axis having one degree of freedom to rotate with respect to the stator. When driven, a balanced three-dimensional magnetic field acts between the stator (2) and the rotor (1) when driven, and each vector of magnetic lines of force representing the magnetic field is A rotating electric device having a dynamic component parallel to a rotation axis. 18. The rotary electric machine according to claim 18, wherein the sum of all dynamic components parallel to the rotation axis is zero. 19. A stator (2) having a core made of a magnetizable material and a winding (8), and a rotor (1) rotating with one degree of freedom relative to the stator.
Wherein the stator (2) surrounds the rotor (1) from all sides and the winding (8) has a cable (5). . 20. The electric machine according to claim 17, wherein the cable is a high-voltage cable.