JP2005304245A - Axial-gap type rotating-electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial-gap type rotating-electric machine formed with permanent magnets on a rotor, capable of reducing leakage flux between the permanent magnets so as to increase generated torque by adding magnet torque to reluctance torque. <P>SOLUTION: A body of the rotor 3 is fixed to a rotor shaft 2. The body of the rotor 3 is formed by laminating electromagnetic steel sheets 11 which is a ferromagnetic body. A plurality of the permanent magnets 12 are mounted in a circumferential direction in the electromagnetic steel sheets 11 as the body of the rotor 3. Air gaps 14 opening in the circumferential direction are formed between the permanent magnets 12 and the electromagnetic steel sheets 11 at a portion sandwiched between the circumferentially neighboring permanent magnets 12, 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for increasing the generated torque in an axial gap type rotating electrical machine in which at least a pair of a stator and a rotor are arranged to face each other in the rotation axis direction.

As an invention of a rotor of an axial gap type rotating electrical machine, a conventional one such as that disclosed in Patent Document 1 has been known.
In the axial gap type rotating electrical machine described in Patent Document 1, a rotor disk and a rotating shaft of a rotor are integrally formed of a nonmagnetic material, and a permanent magnet formed in a cylindrical shape is rotated on a rotor disk of the rotor. Embed in the direction penetrating. Thus, the rotor is integrally and firmly formed to prevent the permanent magnets from being scattered by centrifugal force during high-speed rotation.
JP-A-5-268754, paragraph number 0021

In the axial gap type rotating electrical machine described in Patent Document 1, when the rotor disk of the rotor is formed of a non-magnetic material, the generated torque is only the magnet torque. In order to increase the generated torque, it is preferable to obtain reluctance torque in addition to magnet torque. Therefore, it is conceivable that the rotor disk is formed of a ferromagnetic material to obtain reluctance torque.
However, the conventional axial gap type rotating electrical machine has the following problems. In other words, if the material of the rotor disk is changed from a non-magnetic material to a ferromagnetic material, the leakage magnetic flux between the permanent magnets, particularly the leakage magnetic flux between the permanent magnets adjacent in the circumferential direction, increases via the rotor disk, Compared to the case where the rotor disk is made of a non-magnetic material, there is a problem that the generated torque is reduced.

  An object of the present invention is to propose an axial gap type rotating electrical machine capable of obtaining magnet torque and reluctance torque by reducing leakage magnetic flux between permanent magnets and adding them to increase generated torque. To do.

For this purpose, the axial gap type rotating electrical machine according to the present invention is as described in claim 1,
An axial gap type in which a rotor having a permanent magnet embedded in a rotor body made of a ferromagnetic material and a stator having a field winding are arranged facing each other in the direction of the rotation axis of the rotor. In rotating electrical machines,
A non-magnetic layer is provided between the permanent magnets adjacent in the circumferential direction of the rotor.

  According to the configuration of the present invention, since the nonmagnetic layer provided on the rotor suppresses leakage magnetic flux between the permanent magnets adjacent in the circumferential direction, it is possible to obtain magnet torque and reluctance torque, and generate torque Can be greatly increased.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 is a longitudinal sectional view showing an axial gap type rotating electrical machine according to an embodiment of the present invention in a cross section in a plane including a rotating shaft of a rotor. In this embodiment, a rotor shaft 2 serving as a rotation shaft, a disk-shaped rotor 3 fixed to the rotor shaft 2, and a stator 4 provided to face the rotor 3 are accommodated in a case 5. Thus, the axial gap type rotating electrical machine 1 is configured.

Here, the rotor shaft 2 is rotatably mounted on the case 5 via a bearing 6, and a rotation sensor 7 for detecting the rotational position of the rotor shaft 2 and the like is provided on the rotor shaft 2 of the case 5.
The stator 4 includes a back core portion 8, a stator teeth portion 9, and a winding 10. The back core portion 8 serves to fix the stator tooth portion 9 to the case 5 and to rotate the magnetic flux of the stator tooth portion 9 in the circumferential direction to flow to another stator tooth portion 9. Further, the stator tooth portion 9 winds the winding 10 at a portion where the magnetic flux flows in the circumferential direction. Winding 10 is insulated from stator teeth portion 9 via insulating paper and an insulator (not shown).

The rotor 3 is formed by laminating electromagnetic steel plates 11 such as silicon steel plates having a thickness of 0.2 mm in the axial direction of the rotor shaft 2, and a plurality of embedded portions are formed from the surface 3 m facing the stator 4 to the inside of the rotor 3. The embedded permanent magnet 12 is embedded and attached. Therefore, a hole 11h for embedding and attaching the permanent magnet 12 is punched in the electromagnetic steel sheet 11 as will be described later. In addition, manufacturing cost reduction is possible by making at least one part of the electromagnetic steel plate 11 into a general steel plate.
The rotor 3 and the stator 4 are disposed in the axial direction of the rotor shaft 2, and an axial gap (gap) 13 is provided between the rotor 3 and the stator 4 so as not to contact each other.

FIG. 2 is a front view showing a state in which the rotor 3 of this embodiment is viewed in the axial direction of the rotor shaft 2 from the stator 4 side. The rotor 3 is provided with holes 11h for providing the permanent magnets 12 in the circumferential direction. Therefore, on the side close to the stator 4 of the rotor 3, an electromagnetic steel plate 11a having a hole 11h for attaching the permanent magnet 12 and a hole 11r through which the rotor shaft 2 passes, as described later, is provided on the axis of the rotor shaft 2. Laminate in the direction.
In this embodiment, the rotor 3 has 8 poles, and one permanent magnet is attached per pole. For this reason, the rotor 3 is provided with eight holes 11h evenly in the circumferential direction, and fan-shaped permanent magnets 12 are attached to the respective holes 11h. The dimension of the hole 11h in the circumferential direction is larger than the dimension of the permanent magnet 12 in the circumferential direction. Therefore, with the permanent magnet 12 attached, air gaps (air gaps) 14 are provided on both side surfaces 12s facing the circumferential direction on the surface of the permanent magnet 12 so as not to contact the electromagnetic steel sheet 11. Since air is a nonmagnetic material, the air gap 14 is equal to the nonmagnetic material layer.

  Further, the magnetic pole surface of the permanent magnet 12 shown in FIG. 2 is set to N in the circumferential direction so that the magnetic flux in the axial direction of the rotor shaft 2 of the permanent magnet 12 is opposite to each other in the neighboring permanent magnets in the circumferential direction. S Install alternately.

  FIG. 3 is a developed cross-sectional view of the rotor 3 taken along the line AA in FIG. 2 extending in the circumferential direction and viewed from the direction of the arrow. On the side close to the stator 4 of the rotor 3, an electromagnetic steel plate 11a having a hole 11h for attaching the permanent magnet 12 and a hole 11r through which the rotor shaft 2 passes is laminated. On the other hand, on the side far from the stator 4, an electromagnetic steel plate 11 b having only a hole 11 r through which the rotor shaft 2 penetrates (when viewed from the axial direction of the rotor shaft 2) is laminated. Of the surface of the permanent magnet 12, the bottom surface 12b far from the stator 4 is in contact with the electromagnetic steel plate 11b.

  Thus, the air gap 14 provided on the side surface 12s of the permanent magnet 12 makes it possible to reduce the magnetic flux leakage between the adjacent permanent magnets 12 in the circumferential direction, and increase the generated torque by obtaining the magnet torque and the reluctance torque. Can be made.

  In this embodiment, one permanent magnet is disposed per pole. However, in addition to the embodiment shown in FIG. 3, the permanent magnet 12 is disposed in the axial direction of the rotor shaft 2 as shown in FIG. The magnetic flux passing through the electromagnetic steel sheet 11 is increased by dividing the magnet into two parts, the permanent magnet 12a on the surface 3m side and the permanent magnet 12b inside the rotor 3, and the electromagnetic steel sheet 11b interposed therebetween. Thus, a larger reluctance torque can be obtained, and the generated torque of the axial gap type rotating electrical machine 1 can be increased.

  Alternatively, by applying the same technical idea, the permanent magnet 12 may be divided into three or more parts in the axial direction of the rotor shaft 2, and the electromagnetic steel plates 11b may be inserted between the divided permanent magnets 12, respectively. The reluctance torque can be obtained and the generated torque of the axial gap type rotating electrical machine 1 can be increased.

  Also in this embodiment, the manufacturing cost can be reduced by using at least a part of the electromagnetic steel plates 11a and 11b as general steel plates.

Next, an axial gap type rotating electrical machine according to another embodiment of the present invention will be described.
In this embodiment, an air gap 15 to be described later is additionally provided in FIG. 1 and the rotor 3 according to the above-described embodiment, and FIG. 5 shows the rotor 3 viewed from the stator 4 side. FIG.
A permanent magnet 12 is embedded in the middle of the peripheral edge 3 s of the rotor 3 and the rotor shaft 2, and the electromagnetic steel plate 11 is left on the peripheral edge 3 s of the rotor 3. And the air gap 15 which is the space | gap opened in the circumferential direction is provided in the circumferential direction center part of the electromagnetic steel plate 11s which exists in the radial direction outer side than the permanent magnet 12 and is radial inward from the peripheral edge 3s.

Thus, by providing the air gap 15 at the peripheral edge 3s of the rotor 3, the path of the eddy current flowing through the peripheral edge 3s can be cut off, and the iron loss of the rotor 3 can be reduced. Therefore, the generated torque can be increased by obtaining a larger magnet torque and reluctance torque.
Although not shown in the drawing, even if an air gap opened in the circumferential direction is provided in the electromagnetic steel plate 11 between the permanent magnet 12 and the rotor shaft 2, the eddy current is reduced and the rotor is reduced in the same manner as described above. 3 iron loss can be reduced.

Next, an axial gap type rotating electrical machine according to still another embodiment of the present invention will be described.
FIG. 6 is a front view showing a state in which the rotor 3 of this embodiment is viewed from the axial direction of the rotor shaft 2. This embodiment is basically the same as FIG. 1 and the rotor 3 according to the above-described embodiment, but different portions will be described by adding new reference numerals. A convex portion 11 t is provided so as to protrude from the permanent magnet 12 toward the permanent magnet 12. The protruding height of the convex portion 11t is the same as the gap width of the air gap 14, and the convex portion 11t prevents the permanent magnet 12 from moving in the hole 11h in the direction of closing the gap of the air gap 14. 12 is fixed to the circumferential center position in the hole 11h.

  Further, in FIG. 6, a convex portion 11 u is provided at the central portion of the surface defining the hole 11 h radially inward so as to protrude from the electromagnetic steel plate 11 toward the permanent magnet 12. Is provided with a recess 12u having the same dimensions as the protrusion 11u. And the permanent magnet 12 is embedded and attached to the hole 11h by fitting the convex part 11u of the electromagnetic steel plate 11 to the concave part 12u of the permanent magnet 12. FIG.

Thus, by providing the magnetic steel sheet 11 with the convex portions 11t and 11u and providing the permanent magnet 12 with the concave portion 12u, it becomes easy to arrange and position the permanent magnet 12 during factory assembly, and the permanent magnet 12 is attached to the rotor 3. Accurate and quick assembly is possible. Furthermore, the quality of the gap width of the air gap 14 can be accurately controlled. Further, it is possible to prevent the permanent magnet 12 from moving in the hole 11h in the direction of closing the air gap 14 during the high speed rotation of the rotor 3.
Although not shown in the figure, applying the above technical idea, the permanent magnet 12 is provided with a convex portion, and the electromagnetic steel sheet 11 is provided with a concave portion to fit the same, and the same operation and effect are obtained. Of course, it can be played.

The axial gap type rotating electrical machine according to the present invention can be applied to a combination of a pair of stators and rotors including one rotor 3 and one stator 4 as described above, but also to other combinations. be able to. Therefore, an axial gap type rotating electrical machine according to another embodiment of the present invention will be described.
FIG. 7 is a longitudinal sectional view showing an axial gap type rotating electrical machine according to another embodiment of the present invention in a cross section along a plane including the rotating shaft of the rotor. In this embodiment, the rotor 3 is fixedly provided at the center of the rotor shaft 2, and the two stators 4 are provided facing each other so as to sandwich the rotor 3 from both sides in the axial direction of the rotor shaft 2. .
For this reason, the rotor 3 faces the stator 4 on both the front and the back, and axial gaps 13 are provided on both sides.
The electromagnetic steel plate 11 that is the main body of the rotor 3 is provided with a hole 11h that penetrates in the axial direction of the rotor shaft 2, and the hole 11h is provided with a permanent magnet 12 that penetrates in the axial direction of the rotor shaft 2.

Also in the present embodiment, the front view of the rotor 3 viewed from the stator 4 side is the same as FIG. 2 described above, and the front and back are also the same.
FIG. 8 is a developed cross-sectional view of the rotor 3 of the present embodiment taken along the line AA in FIG. Since the permanent magnets 12 are provided so as to penetrate the stator 3, air gaps 14 are provided on both side surfaces 12 s facing the circumferential direction of the permanent magnets 12 so as not to contact the electromagnetic steel sheet 11.

  Thus, the air gap 14 provided on the side surface 12s of the permanent magnet 12 makes it possible to reduce the magnetic flux leakage between the adjacent permanent magnets 12 in the circumferential direction, and increase the generated torque by obtaining the magnet torque and the reluctance torque. Can be made.

In addition to the present embodiment shown in FIG. 8, a convex portion 11t may be provided at the center of the air gap 14 so as to protrude from the electromagnetic steel plate 11 toward the permanent magnet 12, as shown in FIG. . The protruding height of the protrusion 11t is the same as the gap width of the air gap 14, and the permanent magnet 12 is prevented from moving in the hole 11h in the direction of closing the gap of the air gap 14.
By providing the convex portions 11t on the electromagnetic steel sheet 11 in this way, the permanent magnets 12 can be easily arranged and positioned during factory assembly, and the permanent magnets 12 can be assembled to the rotor 3 accurately and quickly. Furthermore, the quality of the gap width of the air gap 14 can be accurately controlled.

  Alternatively, as shown in FIG. 10, the permanent magnet 12 is divided into two equal parts in the axial direction of the rotor shaft 2, and the magnetic steel sheet 11 b is interposed therebetween, thereby increasing the magnetic flux passing through the electromagnetic steel sheet 11. A large reluctance torque can be obtained, and the generated torque of the axial gap type rotating electrical machine 1 can be increased.

Alternatively, as shown in FIG. 11, an air gap 16 opened in the circumferential direction may be additionally provided in the electromagnetic steel sheet 11 located between the permanent magnet air gaps 12 adjacent in the circumferential direction.
As described above, by providing the air gap 16 in the central portion between the adjacent permanent magnets 12, it is possible to reduce iron loss due to leakage magnetic flux and eddy current between the permanent magnets 12. Therefore, the generated torque can be increased by obtaining a larger magnet torque and reluctance torque.

By the way, according to each above-mentioned Example, in the rotor 3 which attached the permanent magnet 12 to the electromagnetic steel plate 11 which is a ferromagnetic material, it was pinched | interposed into the permanent magnets 12 and 12 adjacent in the circumferential direction among the rotors 3. Since the air gaps 14 and 16 that are non-magnetic layers are provided at the locations, the leakage magnetic flux between the permanent magnets 12 and 12 can be reduced, and magnet torque and reluctance torque can be obtained to obtain an axial gap type. The generated torque of the rotating electrical machine 1 can be increased.
Although not shown in the drawing, although the effect is inferior to that of providing air gaps 14 on both side surfaces 12s and 12s of the portion sandwiched between the adjacent permanent magnets 12 and 12 in the circumferential direction, one side of the permanent magnet 12 is provided. An air gap 14 may be provided on the surface 12s.

In the present embodiment, the air gaps 14 and 16 are provided between the permanent magnets 12 and 12 adjacent in the circumferential direction. However, the air gap is generally filled with a gas such as air. The “non-magnetic layer” in Item 1 includes an air gap (void) that is a non-magnetic layer using air, and also includes other gases and solids.
In addition, the “air gap” in claim 2 or less may be a vacuum state in which nothing is filled in the air gaps 14, 15, 16. This is because vacuum is also a non-magnetic material.

  Further, by providing the air gap 14 between the surface 12s facing the circumferential direction of the surface of the permanent magnet 12 and the electromagnetic steel plate 11, the hole 11h for attaching the permanent magnet 12 can also serve as the air gap. It becomes. Therefore, it is not necessary to perform die-cutting for the air gap only on the electromagnetic steel sheet 11, and the number of man-hours can be reduced.

Further, in the above-described embodiment, the convex portion 11 t is provided in the central portion of the air gap 14 so as to protrude from the electromagnetic steel plate 11 toward the surface 12 s of the permanent magnet 12.
Thereby, at the time of factory assembly, the arrangement and positioning of the permanent magnets 12 are facilitated, and the permanent magnets 12 can be assembled to the rotor 3 accurately and quickly. Furthermore, the quality of the air gap 14 can be accurately controlled, and the permanent magnet 12 can be prevented from being displaced in the hole 11h while the rotor 3 is rotating.
Although not shown in the drawing, a convex portion may be provided on the surface 12 s of the permanent magnet 12. Alternatively, convex portions may be provided at both ends of the air gap 14.

Further, in the above embodiment, by providing the air gap 15 that is a gap opened in the circumferential direction in the central portion in the circumferential direction of the electromagnetic steel sheet 11s that is radially outward from the permanent magnet 12,
It becomes possible to interrupt the path of the eddy current flowing through the peripheral edge 3s, and the iron loss of the rotor 3 can be reduced. Therefore, the generated torque can be increased by obtaining a larger magnet torque and reluctance torque.
Although not shown in the drawing, even if an air gap opened in the circumferential direction is provided in the electromagnetic steel plate 11 between the permanent magnet 12 and the rotor shaft 2, the eddy current is reduced and the rotor is reduced in the same manner as described above. 3 iron loss can be reduced.

In addition, in the hole 11h for attaching the permanent magnet 12, a convex portion 11u is provided so as to protrude from the electromagnetic steel plate 11 toward the permanent magnet 12, and this convex portion 11u is fitted into the concave portion 12u provided in the permanent magnet 12,
At the time of factory assembly, the arrangement and positioning of the permanent magnet 12 are facilitated, and the permanent magnet 12 can be assembled to the rotor 3 accurately and quickly. Furthermore, the quality of the air gap 14 can be accurately controlled, and the permanent magnet 12 can be prevented from shifting in the hole 11h while the rotor 3 is rotating.

  Moreover, in order to obtain reluctance torque, when forming the main body of the rotor 3 with a ferromagnetic material, it is possible to reduce the iron loss by forming the electromagnetic steel plates 11 in a laminated manner.

  In particular, the permanent magnet 12 is divided into two or more in the axial direction of the rotor shaft 2, and the electromagnetic steel sheet 11, which is a ferromagnetic material, is interposed between the divided permanent magnets 12, thereby It is possible to increase the magnetic flux passing through the coil and obtain a larger reluctance torque, and to increase the torque generated by the axial gap type rotating electrical machine 1.

  Further, of the material of the electromagnetic steel plate 11a provided with the hole 11h and the material of the electromagnetic steel plate 11b not provided with the hole 11h, one type is a general steel plate, and at least a part of the electromagnetic steel plate 11 is a general steel plate. Manufacturing costs can be reduced by combining ferromagnetic materials made of the above materials.

  In the embodiment described above, one permanent magnet 12 is disposed per pole when viewed from the axial direction of the rotor shaft 2, but in addition to the embodiment described above, a plurality of permanent magnets 12 are arranged in the radial direction of the rotor 3. Even if magnets are provided and these permanent magnets constitute a permanent magnet per pole, the same effect can be obtained.

It is a longitudinal cross-sectional view for demonstrating the axial gap type rotary electric machine which becomes one Example of this invention. It is a front view for demonstrating the rotor of the Example. It is sectional drawing which expand | deploys and shows the rotor of the Example in the circumferential direction cross section. It is sectional drawing which expand | deploys and shows the rotor which becomes another Example in the circumferential direction cross section. It is a front view which shows the rotor in order to demonstrate the axial gap type rotary electric machine which becomes the other Example of this invention. It is a front view which shows the rotor in order to demonstrate the axial gap type rotary electric machine which becomes further another Example of this invention. It is a longitudinal cross-sectional view for demonstrating the axial gap type rotary electric machine which becomes another Example of this invention. It is sectional drawing which expand | deploys and shows the rotor of the Example in the circumferential direction cross section. FIG. 7 is a cross-sectional view showing a developed rotor in a circumferential section for explaining an axial gap type rotating electrical machine according to still another embodiment of the present invention. FIG. 7 is a cross-sectional view showing a developed rotor in a circumferential section for explaining an axial gap type rotating electrical machine according to still another embodiment of the present invention. FIG. 5 is a cross-sectional view showing a rotor developed in a circumferential section for explaining an axial gap type rotating electrical machine according to still another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial gap type rotary electric machine 2 Rotor shaft 3 Rotor 4 Stator 5 Case 6 Bearing 7 Magnetic steel plate 8 Permanent magnet 9 Back core part 10 Stator tooth part 11 Winding 12 Permanent magnet 13 Axial gap 14, 15, 16 Air gap

Claims (9)

An axial gap type in which a rotor having a permanent magnet embedded in a rotor body made of a ferromagnetic material and a stator having a field winding are arranged facing each other in the direction of the rotation axis of the rotor. In rotating electrical machines,
An axial gap type rotating electrical machine, wherein a nonmagnetic material layer is provided on the rotor between the permanent magnets adjacent in the circumferential direction. In the axial gap type rotating electrical machine according to claim 1,
The non-magnetic layer is an axial gap type rotating electric machine characterized in that it is a gap opened in the circumferential direction. In the axial gap type rotating electrical machine according to claim 2,
An axial gap type rotating electrical machine, wherein the gap is provided between the permanent magnet and the rotor body. In the axial gap type rotating electrical machine according to claim 3,
An axial gap type rotating electric machine, wherein a convex portion for positioning a permanent magnet is provided on at least one of a surface of a permanent magnet forming the gap and a surface of a rotor body. The axial gap type rotating electrical machine according to any one of claims 2 to 4,
The permanent magnet is embedded in the middle of the periphery and the rotation center of the rotor body, and the rotor body located at least one of the radially outer side and the radially inner side than the permanent magnet has a circumferential direction. An axial gap type rotating electrical machine characterized by providing an open gap. In the axial gap type rotating electrical machine according to any one of claims 1 to 5,
An axial gap type rotating electrical machine characterized in that, among the surface of the permanent magnet and the surface of the rotor body, an uneven portion for positioning the permanent magnet is provided on the surface where both are in contact with each other. In the axial gap type rotating electrical machine according to any one of claims 1 to 6,
The rotor main body is an axial gap type rotating electric machine characterized in that electromagnetic steel plates are laminated. In the axial gap type rotating electrical machine according to any one of claims 1 to 7,
An axial gap type rotating electrical machine, wherein the permanent magnet is divided into a plurality of parts in the direction of the rotation axis, and the ferromagnetic material is interposed between the divided permanent magnets. The axial gap type rotating electrical machine according to any one of claims 1 to 8,
An axial gap type rotating electrical machine, wherein the ferromagnetic material is a combination of a plurality of types of ferromagnetic materials.

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