JPH05268754A - Axial gap electric rotating machine - Google Patents

Abstract

PURPOSE:To realize ultra high speed rotation of several tens of thousands rpm and high output. CONSTITUTION:A stator 11 is constituted of a tubular frame 13, brackets 14, 14 fixed, respectively, to the openings at the opposite ends of the frame 13, back yokes 15, 15 having no slot to be fixed to respective brackets 14, molded Windings 16A, 16A fixed to the brackets 14, 14 on the back yokes 15, 15 and constituting stator windings, and a molded winding 16B fixed to the frame 13 in the center thereof and constituting the stator winding, wherein the stator 11 is split into two sections in a plane including the axis of a rotor 12. The rotor 12 is constituted of a rotary shaft 23 made of a nonmagnetic material, two rotor discs 24, 24 formed integrally with the rotary shaft 23, and a plurality of columnar permanent magnets 25 magnetized in the axial direction and buried in a hole made in the rotor disc 24 in the axial direction thereof. The rotor discs 24, 24 provide an air gap between the molded windings 16A, 16B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-high speed rotating or high output axial gap rotating electric machine.

[0002]

2. Description of the Related Art An ultra-high speed rotating electric machine of 20000 rpm or more has a considerably large centrifugal force during rotation. Therefore, when a permanent magnet is used for the field, the centrifugal force is applied to the permanent magnet so that it will not scatter. A non-magnetic retaining ring having a thickness that can oppose is provided on the outer peripheral surface of the permanent magnet. FIG. 7 shows an example of this structure. Reference numeral 1 is a stator and windings 2 are provided. Reference numeral 3 is a rotor. A permanent magnet 4 is used as a field. The permanent magnet 4 is a thick nonmagnetic material so as not to be scattered by centrifugal force. Is provided on the outer peripheral surface of the permanent magnet 4. Note that reference numeral 6 indicates a rotating shaft, and reference numeral 7 indicates an air gap. When the rotor is provided with a coil, the retaining ring presses the end ring of the coil.

[0003]

[Problems to be Solved by the Invention] However, 20000r
In an ultra-high speed rotating electric machine of pm or more, the centrifugal force during rotation is considerably large, so the rotor coil cannot withstand strength and may be damaged. Further, as shown in the configuration example of FIG. 7 described above, when a permanent magnet is used for the field, a considerably thick non-magnetic retaining ring 5 is required so that the permanent magnet does not scatter. Since a non-magnetic material is used for this retaining ring 5 so that the magnetic circuit is not short-circuited, the magnetic air gap length increases, the magnetomotive force consumed between the air gap portions increases, and the output of the rotating electric machine decreases. To do.

On the other hand, in the axial gap rotating electric machine, when the rotor disk is multi-staged in the conventional structure, the stator disk having windings and the rotor disk are alternately arranged in the direction of the rotation axis, so that the manufacturing is impossible. Therefore, since the rotor disk is composed of only one, the outer diameter of the rotor becomes large, and it is difficult to manufacture a high-speed, high-power rotor.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and provides an axial gap rotating electric machine capable of rotating at an ultrahigh speed of tens of thousands rpm and capable of further increasing the output. It is an object.

[0006]

In order to achieve the above-mentioned object, the present invention comprises a stator and a rotor rotatably supported by the stator, and the stator is a hollow frame body and the frame body. End caps attached to both end openings, a stator core attached to the inner surface side of the end caps and having no slots, and three or more stator windings mounted and molded on the end caps on the frame and the stator core, respectively. Lines, and these are divided into two or more parts in a plane that includes the axial center of the rotor, and the rotor is divided into two parts by an axial gap.
It has a disc portion formed of at least one non-magnetic material, and a permanent magnet magnetized along the axial direction is axially penetrated and fixed to the disc portion.

[0007]

With the above-mentioned structure, firstly, as a mechanical action, a permanent magnet serving as a field is embedded axially through the plane of the disk portion of the rotor.
Therefore, the disk portion of the rotor acts so as to prevent the permanent magnet from jumping out due to centrifugal force at high speed. In a conventional cylindrical electric machine with a radial magnetic circuit that has a field and a winding in the radial direction, if the retaining ring on the outer circumference of the rotor is thickened to resist centrifugal force, the magnetic gap length increases. ..
However, in the present invention, the operating magnetic circuit is formed in the axial direction even if the thickness of the rotor outer peripheral portion of the disk portion is made sufficiently thick, so that the air gap length of the operating portion is not increased and the output is not reduced. High speed rotation is possible. Also, the permanent magnets that form the poles of the field are not one permanent magnet per pole,
Since multiple permanent magnets are dispersed and embedded and fixed in multiple holes provided in the disk part, it is possible to avoid the concentration of stress due to the centrifugal force of the permanent magnets on a part of the disk. Can withstand rotation.

Further, because of the axial gap, the rotor has a top shape similar to that of a flywheel, and the distance between the bearings on both sides that support the disk portion is considerably shortened.
The rigidity of the rotating shaft increases. Therefore, the torsional vibration frequency of the shaft becomes high, and the shaft can be stably rotated with little vibration even at ultra-high speed rotation.

Next, as an electromagnetic effect, since the stator winding is composed only of the winding and the molding resin and there is no rotor iron core, the magnetic circuit has only the stator iron core provided on the inner surface of the end cover, the permanent magnet and the air gap. The magnetic part that forms the magnetic path is only the stator cores on both sides. Therefore, by simply providing the stator winding and the disk portion of the rotor, which can be divided into two or more parts, between the two stator iron cores, the operating portion of the multi-stage rotating electric machine is formed, and high output can be achieved.

Further, since the stator core has no teeth and no rotor core, the magnetic circuit is composed only of the stator core, the permanent magnets and the air gap, and the magnetic portion forming the magnetic path is multi-stage with only two stator cores on both sides. It is possible to create an operating unit of a rotating electric machine. Therefore, the iron loss is significantly reduced, and the efficiency can be increased and the temperature rise during the operation of the rotating electric machine can be reduced.

In the axial gap rotary electric machine, since the circumference on the inner diameter side is naturally shortened, the space at the end of the winding is narrowed, and the number of windings cannot be increased. However, due to the decrease in iron loss described above, it becomes possible to manufacture an ultra-high speed, multi-pole rotating electric machine that can be driven at a higher frequency. , High output.

The stator core is formed by spirally winding a strip-shaped thin magnetic steel sheet, so that iron loss due to generation of eddy current can be suppressed. When teeth are provided on the stator iron core, the air gap magnetic flux pulsates due to the teeth at the time of high-speed rotation, and a considerably large eddy current is generated on the rotor surface. No eddy current is generated and efficiency is improved.

In the stator winding, since the soft magnetic material forming the magnetic path is only the stator core, the magnetic air gap seen from the winding becomes considerably large. Therefore, the inductance of the winding is considerably small, the voltage drop of the inductance is small, and at the same time the terminal voltage is small. Therefore, the drive power source can be downsized. Further, when the magnetic gap becomes large, the armature reaction due to the winding also becomes small, so that it is possible to prevent demagnetization of the permanent magnet attached to the rotor, and it is possible to flow a large current.

On the other hand, according to the present invention, in order to increase the output, a multi-stage operation unit is used, and the disc portion of the rotor and the formed stator winding are alternately arranged in the axial direction. Therefore,
The stator has a structure that can be divided within a plane including the axis of the rotating shaft, and the rotor can be accommodated in the divided state. At the same time, to make the stator windings separable as well, a one-sided winding method (or concentric winding method) is used to form an imaginary pole between the real pole and the real pole, and the center of the imaginary pole is on the split line of the stator. I try to exist. This prevents the conductors in the molded windings from being cut in order to divide the stator.

As described above, the present invention is an axial gap rotating electric machine and can be divided into two or more parts in a plane including the axis of the rotating shaft, so that the rotor can be easily taken out and maintenance is facilitated. .. Furthermore, since the stator winding is formed by the stator winding alone without being wound around the teeth of the iron core as in the conventional case, the stator is divided into
Only the stator winding can be easily taken out, and the stator winding can be easily replaced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of the present invention by cutting it. In the figure, reference numeral 10 denotes an axial gap rotating electric machine, which is composed of a stator 11 and a rotor 12 rotatably supported by the stator 11 via bearings.

In this structure, the stator 11 is housed in a frame 13 formed in a substantially cylindrical shape, brackets 14 and 14 attached to opening portions at both ends of the frame 13, and recesses provided in the brackets 14, respectively. Slotted back yokes 15 and 15, mold windings 16A and 16A that form the stator windings that are attached to the bracket 14 on the back yokes, and the starter winding that is attached to the center of the frame 13. The molded windings 16B are formed by the rotor 12 as shown in FIG.
It has a structure in which it is divided into two up and down in a plane including the axis of.

The above-mentioned mold windings 16A and 16B are formed in a disk shape as a whole, and as shown in FIG. 3, they are composed of two pieces which are divided into upper and lower parts into a semicircular shape, and each of them has 3 pieces. U, V, and W phase windings 17 are provided at the positions, and these windings 17 are integrated by a molding resin layer 18 of epoxy resin. Here, the winding 17 adopts a one-way winding method (or a concentric winding method) to form a real pole (N pole) and an imaginary pole (S pole) as shown in FIG. Is the stator
It should be on the dividing line of 11.

Further, a through hole 19 for a bolt for attaching to the bracket 14 or the frame 13 is provided in a portion near the outer peripheral side of the molded resin layer 18. Further, the molded resin layer 18 has U,
A terminal (not shown) for connecting a cable drawn from the external power source through the frame 13 to the V and W windings 17
May be provided on the side surface (or a lead wire may be drawn out from the end of the winding 17 and the lead wire may be passed through a hole provided in the frame 13 to be connected to the cable outside the frame 13). ..

The back yoke 15 is made of a strip-shaped silicon steel plate 20 having a thickness of 0.2 mm as shown in FIGS.
Is wound in a spiral shape, and is sandwiched between the outer ring 21 and the inner ring 22 and fixed, and then is divided into two parts up and down, which is attached to the bracket 14 as a semicircular yoke.

Further, the rotor 12 includes a rotary shaft 23 made of a non-magnetic material, two rotor disks 24, 24 integrally formed at an intermediate portion of the rotary shaft 23 in the axial direction, and each rotor disk. As shown in FIG. 6, 24 permanent magnets 25 are installed at 12 locations evenly arranged, and 10 magnets are dispersedly attached to each location. Here, the permanent magnet 25 is formed in a cylindrical shape and is magnetized along the axial direction, and is inserted and fixed in a hole provided along the axial direction in the plane of the rotor disk 24.

Further, the rotor disk 24 has a mold winding 16
It is arranged so that an axial gap 26 is formed between A and 16B. On the other hand, the field poles created on the rotor disk 24 are
Ten permanent magnets 25 are dispersed and arranged as shown in FIG. 6 to form one pole. In this embodiment, since there are 12 poles, 120 permanent magnets 25 are provided for each rotor disk.

Next, the operation of the embodiment configured as described above will be described. First, in terms of mechanical structure, a permanent magnet 25 serving as a field is embedded in the plane of the rotor disk 24 so as to penetrate in the axial direction. Therefore, the rotor disc
24 acts so as to prevent the permanent magnet 25 from jumping out by centrifugal force during high-speed rotation. In order to increase the centrifugal resistance, it is necessary to make the rotor disk 24 sufficiently thick.
In the conventional cylindrical electric machine of the radial magnetic circuit having the field and winding in the radial direction shown in FIG. 7, if the holding ring 5 provided on the outer circumference of the rotor for thickening the centrifugal force is thickened, The space 7 becomes long.

However, in the rotating electric machine of the present embodiment, even if the outer peripheral portion of the rotor disk 24 is made sufficiently thick, the magnetic field produced by the permanent magnet 25 is formed in the direction of the rotation axis, so that the magnetic circuit of the magnetic circuit is magnetic. The number of voids does not increase. Therefore,
By increasing the mechanical strength as the centrifugal force resistance, the output does not decrease and high speed rotation becomes possible. Further, the permanent magnets 25 forming the field poles are not one permanent magnet per pole, but in this embodiment, ten cylindrical permanent magnets 25 per pole are dispersed to form a rotor disk. Since it is embedded in the 10 holes of 24, it becomes possible to avoid the stress due to the centrifugal force of the permanent magnet 25 from concentrating on a part of the rotor disk 24, and it is possible to withstand ultra-high speed rotation.

Since the rotary electric machine of this embodiment has an axial gap, the rotor 12 has a top shape similar to a flywheel, and the distance between the bearings on both sides supporting the rotor disk 24 is considerably shortened. The rigidity of the rotating shaft increases. Therefore, the torsional vibration frequency of the shaft becomes high, and the shaft can be stably rotated with little vibration even at ultra-high speed rotation.

Next, on the electromagnetic side, since the winding portion is composed only of the winding wire 17 and the molding resin layer 18 and there is no rotor iron core, the magnetic circuit has two magnetic coils provided on the inner surface of the bracket 14. The two back yokes 15 on both sides have a magnetic part that is composed of only the yoke 15, the permanent magnet 25 and the air gap 26 and forms a magnetic path.
Will only be. Therefore, the mold windings 16A and 16B and the rotor disk 24 that can be divided into two or more pieces are divided into two back yokes 15.
Only by alternately arranging them one after the other, the operating part of the multi-stage rotating electric machine is formed, and high output can be achieved.

Since the stator iron core has no teeth and the rotor iron core does not exist, the magnetic circuit is composed of the back yoke 15 and the permanent magnet 25.
And the magnetic parts that form the magnetic path only by the two back yokes 15 on both sides can form the operating part of the multi-stage rotating electric machine. Therefore, the iron loss is significantly reduced, and the efficiency can be increased and the temperature rise during the operation of the rotating electric machine can be reduced.

In the axial gap rotating electric machine, since the circumference on the inner diameter side is naturally shortened, the space at the end of the winding 17 is narrowed, and the number of windings cannot be increased. However, due to the decrease in iron loss described above, it becomes possible to manufacture an ultrahigh-speed, multi-pole rotating electric machine that is driven at a higher frequency, and since the number of multi-poles is increased, the end of the winding 17 is shortened and the number of windings is reduced. Increased, resulting in higher output.

The back yoke 15 is formed by spirally winding a strip-shaped silicon steel plate 20 having a thickness of 0.2 mm, sandwiching it between the outer ring 21 and the inner ring 22, and fixing the iron steel by generating an eddy current. It controls the loss. In a rotating electrical machine with teeth on the stator core, the teeth of the stator core cause
The air gap magnetic flux pulsates and a considerably large eddy current is generated on the rotor surface. However, since the rotating electrical machine of this embodiment does not have the teeth of the iron core, this eddy current does not occur and the efficiency is improved.

In the winding 17, the soft magnetic material forming the magnetic path is only the back yoke 15, and the magnetic air gap seen from the winding 17 is considerably large. Therefore, the inductance of the winding 17 is considerably small, the voltage drop of the inductance is small, and at the same time the terminal voltage is small. Therefore, the drive power source can be downsized.

When the magnetic gap becomes large, the winding
Since the armature reaction by 17 is also reduced, it is possible to prevent demagnetization of the permanent magnet 25 attached to the rotor 12, and it is possible to flow a large current.

Next, the division of the stator 11 will be described. The rotating electric machine of the present invention has a multi-stage operation unit for high output, and has a rotor disk 24 and a molded winding 16A formed by molding.
16B are alternately arranged in the axial direction. for that reason,
It is difficult to fit the rotor 12 in the stator 11. Therefore, in the rotating electric machine of the present invention, the stator 11 is the rotor 12
Since it has a structure in which the rotor 11 is divided into two parts in a plane including the axis center of, the stator 11 can be divided into two parts to accommodate the rotor 12. Disc-shaped mold winding 16
Since A and 16B have a structure in which they are divided into two, one-side winding method (or concentric winding method) is adopted to form a winding that alternately forms a real pole and an imaginary pole, and the center of the imaginary pole is divided into two parts of the stator 11. I try to exist on the line. Specifically, when two adjacent windings both form an N pole, an imaginary S pole is formed between the windings. Therefore, by setting the center of this imaginary pole on the bisector of the stator 11,
Since 11 is divided into two, the conductors in the mold windings 16A and 16B are not cut, and the rotary electric machine of the present invention can be configured.

The present invention is an axial gap type,
Since the rotor 12 can be divided into two in a plane including the axial center of the rotor 12, the rotor 12 can be easily taken out from the stator 11 and maintenance becomes easy. Further, since the winding 17 is formed by the mold winding alone without being wound around the teeth of the iron core as in the conventional case, the stator 11 is divided into the mold windings 16A and 16A.
Only B can be taken out easily, and the winding 17 can be easily replaced.

Further, as described above, by arranging a large number of cylindrical permanent magnets 25 by shifting them from the same radial direction by an arbitrary angle as shown in FIG. 6, the skew effect can be easily obtained and the induced voltage can be increased. The waveform can be changed to a sine wave to reduce output pulsation.

In the embodiment described above, the winding 17 is molded with epoxy resin. However, by applying semiconductor technology, a semi-circular winding in which a conductive wire is printed on a substrate of a thin electric insulator. The same effect can be obtained by stacking the layers.

[0036]

As described above, according to the present invention, since a plurality of permanent magnets serving as field magnets are embedded in the rotor disk, the stress due to the centrifugal force is not concentrated on a part of the magnet. High-speed rotation is possible, and because the stator has a split structure, the stator windings and rotor disks can be arranged alternately to form multiple stages, making it easier to increase the output and removing the upper half of the stator. This makes it possible to provide an axial gap rotating electric machine that facilitates maintenance of the windings and the rotor.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of an embodiment of the present invention by cutting.

FIG. 2 is an explanatory view schematically showing a stator according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of a mold winding according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a back yoke according to an embodiment of the present invention.

5 is a plan view taken along the line AA of FIG.

FIG. 6 is a plan view showing a state where permanent magnets are embedded in a rotor disk according to an embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a conventional permanent magnet rotating electric machine.

[Explanation of symbols]

11 ... Stator, 12 ... Rotor, 13 ... Frame, 14 ... Bracket, 15 ... Back yoke, 16A, 16B ... Mold winding,
17 ... Winding, 18 ... Molded resin layer, 20 ... Silicon steel plate, 21 ... Outer ring, 22 ... Inner ring, 23 ... Rotating shaft, 24 ... Rotor disk, 25 ... Permanent magnet, 26 ... Void.

Claims (4)

[Claims] 1. A stator, comprising a rotor rotatably supported by the stator, the stator comprising a hollow frame body, end caps attached to openings at both ends of the frame body, and It has a stator iron core attached to the inner surface side and having no slot, and three or more stator windings respectively attached and molded to the end cover on the frame body and the stator iron core, and these are stator shafts of the rotor. The rotor is divided into two or more parts in a plane including the core, and the rotor is
An axial structure having a disc portion formed of two or more non-magnetic materials via an axial gap, and a permanent magnet magnetized along the axial direction is embedded in the disc portion. Gap rotating electric machine. 2. The axial gap rotating electric machine according to claim 1, wherein the permanent magnet per pole is divided into a plurality of parts, and the permanent magnets are axially penetrated and fixed to the disk part of the rotor. Electric machinery. 3. The axial gap rotating electric machine according to claim 1, wherein the stator core attached to the inner surface side of the end cover is formed into a disc shape by spirally winding a thin magnetic steel plate,
An axial gap rotating electric machine characterized by being divided along the diametrical direction. 4. The axial gap rotary electric machine according to claim 1, wherein the stator windings attached to the end cover on the frame body and the stator iron core are one-sided windings or concentric windings that can be divided along the diameter direction. An axial gap rotating electric machine characterized by being molded with an insulating resin.