JP2015208176A - axial gap type rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial gap type rotary electric machine, whose adjustment of a gap between a rotor and a stator is easy, capable of improving strength of a rotor.SOLUTION: The axial gap type rotary electric machine includes: a rotor 1; and a stator 2 facing the rotor 1 through a gap along a rotation axis direction. The rotor 1 includes: a rotor core 6; a rotor yoke 4, to which a shaft 5 is fixed and the rotor core is fixed; and a permanent magnet 3 connected to the rotor core 6. The rotor yoke 4 is composed of a die-casting metal for molding a portion of the rotor core 6 except for a connection part of the rotor core 6 and the permanent magnet 3 in the rotor core 6.

Description

  The present invention relates to an axial gap type rotating electrical machine.

  In an axial gap type rotating electrical machine, the stator and the rotor face each other through a gap in the axial direction of the rotating shaft. In particular, in an axial gap type rotating electrical machine in which a slot is provided in the stator core portion, the rotor iron loss increases due to the effect of the slot. For this reason, a rotor core in which a thin plate-like magnetic body is laminated in a direction orthogonal to the main magnetic flux is used as the rotor core. As a technique related to such a rotor core, a technique described in Patent Document 1 is known.

  In the present technology, in order to reduce the iron loss and improve the efficiency of the rotating electrical machine, a rotor wound core formed by winding a thin strip (ribbon-shaped) magnetic body in a spiral shape is used. Further, the rotor wound core and the magnet are arranged in a non-magnetic reinforcing frame, and these members are molded and integrated with a resin which is an insulating material to constitute a rotor.

JP 2013-90487 A

  In an axial gap type rotating electrical machine, it is necessary to keep a gap (gap) between the opposing rotor surface and stator surface uniform. On the other hand, in the above prior art, it is difficult to adjust the gap at the time of assembling the rotating electrical machine due to the variation in the thickness of the resin mold. For this reason, a manufacturing cost becomes high. Moreover, in the said prior art, since it is resin mold, it is difficult to improve the intensity | strength of a rotor and it is difficult to increase the speed of a rotary electric machine.

  Therefore, the present invention provides an axial gap type rotating electrical machine that can easily adjust the gap between the rotor and the stator and can improve the strength of the rotor.

  In order to solve the above problems, an axial gap type rotating electrical machine according to the present invention includes a rotor and a stator facing the rotor through a gap along the direction of the rotation axis. The child has an iron core, a yoke to which the shaft is fixed and the iron core is fixed, and a permanent magnet connected to the iron core. The yoke is a portion of the iron core excluding the connecting portion between the iron core and the permanent magnet. Made of die-cast metal to be molded.

  Since the yoke is made of die-cast metal that molds a portion of the iron core other than the connection with the permanent magnet, the dimensional accuracy of the rotor is improved and the strength of the rotor is improved. Therefore, it is easy to adjust the gap between the rotor and the stator, and the speed of the rotating electrical machine can be increased.

  Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

1 is a perspective view showing an outline of the overall configuration of an axial gap motor that is Embodiment 1 of the present invention. FIG. The structure of a rotor is shown. A spiral rotor core is shown. The rotor iron core fixed to the rotor yoke is shown. The modification of a rotor core is shown. The rotor to which the permanent magnet was connected is shown. 6 shows a rotor in which a part of a rotor core of an axial gap type motor that is Embodiment 2 of the present invention and a permanent magnet are not placed. 6 shows a rotor and a structural member of the rotor in which a permanent magnet of an axial gap type motor that is Embodiment 3 of the present invention is not mounted. FIG. 6 shows a rotor and a part of a rotor core in which a permanent magnet of an axial gap type motor that is Embodiment 4 of the present invention is not mounted. A manufacturing method of a rotor of an axial gap type motor which is Example 5 of the present invention will be described.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing an outline of the overall configuration of an axial gap type rotating electrical machine that is Embodiment 1 of the present invention. The rotating electrical machine shown in this figure is an axial gap type motor.

  In the present embodiment, two disk-shaped rotors 1 are arranged to face each other so that the magnet surfaces face each other. A shaft 5 serving as a rotation shaft of the motor is fixed to each rotor 1 by a known method such as shrink fitting so as to pass through the center of each rotor 1. Between the two rotors 1, a stator 2 that faces each of the rotors 1 is disposed in the direction of the rotation axis via a gap (air gap). The shaft 5 is rotatably inserted into the central portion of the stator 2.

  Although not shown in detail, the stator 2 includes a stator core having a plurality of slots and a stator winding that is positioned in each slot and wound on an insulating bobbin that is attached to the stator core. . Thus, the stator 2 including the stator core, the insulating bobbin, and the stator winding is housed in the cylindrical housing 20 together with the rotor 1 and is integrally molded with the housing 20 by resin so that the housing 20 is molded into the housing 20. Fixed.

  FIG. 2 shows the structure of the rotor. In this figure, for easy understanding of the structure, each part is shown in a separated state.

  As shown in FIG. 2, the rotor 1 includes a rotor core 6 that is formed by spirally winding a thin ribbon (ribbon) of an electromagnetic steel plate such as a silicon steel plate and has an annular plane shape. In the rotor core 6, thin strips of electromagnetic steel sheets are laminated in an annular radial direction. Thereby, the iron loss which generate | occur | produces in a rotor core by the space harmonic accompanying the change of the magnetic permeance in the space | gap resulting from the slot shape in the stator 2 can be reduced. In place of the electromagnetic steel sheet, an amorphous magnetic material may be applied to reduce the iron loss.

  On the annular plane of the rotor core 6, the number of permanent magnets 3 equal to the number of poles of the rotor 1, that is, four permanent magnets 3 in this embodiment are arranged and fixedly connected. The permanent magnets 3 corresponding to the number of poles of the rotor 1 are plate-shaped magnets each having a substantially fan-like planar shape, and are arranged in an annular shape on the annular plane of the rotor core. The rotor core 6 and the permanent magnet 3 are bonded by an adhesive member such as resin. As the permanent magnet 3, a rare earth magnet or a ferrite magnet can be applied. Further, the permanent magnet is not limited to the one divided into a plurality as in the present embodiment, and a single ring-shaped magnet with a plurality of poles magnetized may be used.

  The rotor core 6 is held by a rotor yoke 4 made of die cast metal. The rotor yoke 4 is formed of a die cast metal on a portion of the rotor core 6 excluding the connecting portion with the permanent magnet 3, that is, on the opposite side of the flat portion to which the permanent magnet 3 is connected in this embodiment, that is, on the back side. It is comprised by molding with. And this die-cast metal adheres to the said back surface and side surface of the rotor core 6, and the rotor core 6 is fixed to the rotor yoke 4. FIG. A circular hole for passing the shaft 5 is provided at the center of the rotor yoke 4. The shaft 5 is fixed to the rotor yoke 4 by being inserted into the hole by shrink fitting or the like. As the die cast metal, a nonmagnetic alloy such as an aluminum alloy is applied.

  FIG. 3 shows a spiral rotor core. The winding start portion and winding end portion of the electromagnetic steel sheet wound in a spiral shape are joined to the rotor core body by welding. Thereby, a spiral shape is maintained. In this embodiment, the winding start portion is a ribbon end portion located on the inner wall portion of the hole in the central portion of the rotor core 6, and the winding end is the outermost peripheral portion of the rotor core 6. It is a ribbon end part located in a side part. In order to reliably hold the spiral shape, the rotor core 6 may be resin-molded. At this time, the surface of the resin is lower than the laminated surface A of the rotor core 6. This prevents the resin from affecting the gap size between the stator and the rotor. In the manufacturing process, the resin molding process may be executed after the die casting process using a high-temperature molten metal.

  FIG. 4 shows the rotor core fixed to the rotor yoke. The rotor yoke 4 made of die-cast metal includes the entire laminated surface of the rotor core 6 on the back side of the laminated surface A exposed in the drawing, the outermost circumferential side surface and the innermost circumferential surface of the rotor core 6. It coats the side surfaces and adheres to these coated surfaces. That is, a portion of the rotor core 6 excluding the laminated surface A on which the permanent magnet 3 is disposed is molded with die-cast metal. Since the rotor core 6 is molded into die-cast metal, deformation of the spiral rotor core 6 is suppressed. Moreover, the die-cast metal which comprises the rotor yoke 4 may be located between the laminated | stacked thin strip layers, and may adhere to a thin strip. As a result, the rotor core 6 is securely fixed to the stator yoke 4. At this time, the die-cast metal surface can be made lower than the laminated surface A, and the laminated surface A on which the permanent magnet 3 is placed can be made flat.

  Such an integrated configuration of the rotor yoke 4 and the rotor core 6 improves the strength of the rotor while using the rotor core 6 in which a magnetic steel sheet ribbon is wound in a spiral shape. Furthermore, since the shaft 5 is fixed to the rotor yoke 4 made of die-cast metal, the shaft 5 is fixed to the spiral rotor core 6 via the rotor yoke 4. Thereby, the fixed strength between the spiral rotor core 6 and the shaft 5 is improved. Further, the rotor yoke 4 made of die-cast metal improves the dimensional accuracy of the rotor, so that the gaps between the rotor and the stator can be made uniform.

  FIG. 5 shows a modification of the rotor core. This variation is configured by winding a magnetic steel sheet ribbon in a spiral shape as in the embodiment of FIG. 3, but unlike the rotor core of FIG. 3, grooves B are provided in the radial direction of the laminated surface. Thereby, in the die-casting process, the molten die-cast metal can surely flow into the inner peripheral side, the interlayer and the outer peripheral side of the rotor core housed in the mold jig and spread. Thereby, the rotor yoke 4 can be manufactured with an accurate shape and with high dimensional accuracy.

  FIG. 6 is a perspective view (a) and a sectional view (b) of a rotor to which a permanent magnet is connected. As shown in FIG. 2, the plate-like permanent magnet 3 is placed on the laminated surface of the rotor core, and is bonded and fixed by an adhesive member such as resin or adhesive. Further, as shown in the cross-sectional view (b), the rotor yoke 4 has a step in the outer peripheral portion and the inner peripheral portion. That is, the outer peripheral portion and the inner peripheral portion of the rotor yoke 4 are higher than the laminated surface of the rotor core 6, so that the integrated rotor yoke 4 and rotor core 6 are combined with the rotor core 6. A recess having a bottom surface of the laminated surface. In this recess, the permanent magnet 3 is bonded onto the laminated surface of the rotor core 6 and the lower part of the step of the rotor yoke 4 in contact therewith. Therefore, the permanent magnet 3 is accurately positioned at a predetermined position with respect to the rotor core 6 by the step portion of the rotor yoke 4.

  As shown in FIG. 6B, a cylindrical portion that forms a hole through which the shaft 5 passes is provided at the center of the rotor yoke 4. The shaft 5 passes through this hole and is fixed to the rotor yoke 4 at the cylindrical portion.

  As described above, according to the present embodiment, the rotor yoke 4 is configured by molding the portion of the rotor core 6 excluding the laminated surface A on which the permanent magnets 3 are arranged with die-cast metal. Then, the die-cast metal constituting the rotor yoke 4 adheres to the rotor core 6 so that the rotor core 6 is fixed to the rotor yoke 4. Thereby, the dimensional accuracy of the rotor is improved and the strength of the rotor is improved. Since the dimensional accuracy of the rotor is improved, it is easy to adjust the gap between the rotor and the stator. Therefore, the rotation of the axial gap type motor can be stabilized. Furthermore, since the strength of the rotor can be improved, the speed of the axial gap motor can be increased.

  Further, since the shaft 5 is directly fixed to the rotor yoke 4, a reinforcing member is not necessary, and the number of parts can be reduced. A rotor yoke is formed by molding the rotor core with die-cast metal, and at the same time, the rotor core and the rotor yoke are integrated. Thereby, the manufacturing process of a motor is simplified and manufacturing cost can be reduced.

  FIG. 7 shows a part (a) of a rotor core of an axial gap type motor that is Embodiment 2 of the present invention, and a rotor (b) on which no permanent magnet is placed. Hereinafter, differences from the first embodiment will be described.

  As shown in FIG. 7A, a part of the rotor core 6 in the present embodiment is configured by laminating thin strips of electromagnetic steel sheets that gradually increase in length toward the outer peripheral side in the radial direction, It has a substantially fan shape. The laminated ribbons are brought into close contact and joined by welding or the like. Then, a plurality of substantially fan-shaped rotor core portions shown in FIG. 7A are arranged in an annular shape as shown in FIG. 7B.

  According to the present embodiment, in addition to the same effects as in the first embodiment, the space factor of the rotor core, that is, the volume ratio of the magnetic material in the rotor core is improved, so that the output of the axial gap motor can be improved. . Further, since the annular rotor core is divided into a plurality of fan-shaped rotor core portions in the circumferential direction, eddy current loss can be reduced.

  FIG. 8 shows a rotor (a) in which a permanent magnet of an axial gap type motor that is Embodiment 3 of the present invention is not mounted, and a structural member (b) of the rotor. Hereinafter, differences from the first and second embodiments will be described.

As shown in FIG. 8A, in the rotor of the present embodiment, a substantially fan-shaped and elongated structural member 7 composed of a plurality of fan-shaped rotor cores similar to those in FIG. Are arranged alternately and in an annular shape. Here, the structural member 7 may be either a magnetic material or a non-magnetic material.
According to the present embodiment, in addition to the same effects as those of the first and second embodiments, the motor performance can be appropriately adjusted depending on the number and size of the rotor cores and the structural members on which the electromagnetic steel sheet ribbons are laminated. .

  FIG. 9 shows a rotor (a) in which a permanent magnet of an axial gap type motor that is Embodiment 4 of the present invention is not mounted, and a part (b) of the rotor core. Hereinafter, differences from the first, second, and third embodiments will be described.

  As shown in FIG. 9B, in a part of the rotor core 6 of the present embodiment, a plurality of thin strips of substantially fan-shaped electromagnetic steel sheets are laminated in the thickness direction of the rotor core. Such a rotor core portion is arranged in an annular shape as shown in FIG.

  According to the present embodiment, eddy current loss can be reduced.

  FIG. 10 is a schematic view showing a method of manufacturing a rotor of an axial gap type motor that is Embodiment 5 of the present invention. This figure is a perspective view (a) showing how the motor component is assembled in the jig, and a sectional view (b) taken along the line AA 'in the perspective view.

  As shown in FIG. 10, in a state where the rotor core 6 shown in FIG. 3 is accommodated, the substantially cylindrical mold jig 30 and the substantially cylindrical mold jig 31 are closed. In FIG. 10B, each part is illustrated separately for easy understanding of the figure. However, with the mold jig 30 and the mold jig 31 closed, the space in the mold jig is sealed except for the molten metal inlet C. In addition, a laminated surface that is a joint surface with the permanent magnet in the rotor core 6 is in close contact with the mold jig 31. Further, there is a space between the mold surface 31 and the laminated surface that is the back surface of the rotor core 6 with the permanent magnet.

  After the mold jigs 30 and 31 are closed, the molten die-cast metal is injected into the space in the mold jig from the molten metal injection port C while applying pressure by a pressure device (not shown). When the molten die-cast metal is cooled and solidified, a rotor yoke made of die-cast metal for molding the back side of the joint surface with the permanent magnet of the rotor core 6 as described above is formed.

  A cylindrical projection is provided at the center of the mold jig 31. The upper surface of this protrusion, that is, the circular surface on the left side of the columnar protrusion in FIG. 10A, is in close contact with the mold jig 30 with the mold jigs 30 and 31 closed. An annular groove is formed around the protrusion. Thereby, the cylindrical part which has a hole part for letting a shaft pass in a rotor yoke is formed.

  By the manufacturing method of the fifth embodiment, an integral structure of the rotor core and the rotor yoke in the rotor of the axial gap motor of the first embodiment can be manufactured.

  In addition, this invention is not limited to the Example mentioned above, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  For example, the present invention is not limited to an axial gap type motor in which two rotors sandwich one stator as shown in FIG. 1, but one having one rotor and one stator, The present invention can also be applied to a case where the stator sandwiches one rotor. The present invention can also be applied to an axial gap generator.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Stator 3 Permanent magnet 4 Rotor yoke 5 Shaft 6 Rotor iron core 7 Structural members 30, 31 Mold jig

Claims (12)

A rotor,
A stator facing the rotor via a gap along the direction of the rotation axis;
In an axial gap type rotating electrical machine comprising:
The rotor is
Iron core,
A yoke to which the shaft is fixed and the iron core is fixed;
A permanent magnet connected to the iron core;
Have
The axial gap type rotating electrical machine, wherein the yoke is made of a die-cast metal that molds a portion of the iron core excluding a connecting portion between the iron core and the permanent magnet. In the axial gap type rotating electrical machine according to claim 1,
The axial gap type rotating electrical machine, wherein the die-cast metal adheres to the iron core. In the axial gap type rotating electrical machine according to claim 1 or 2,
The iron core has a magnetic material laminated in a plurality of layers, and is an axial gap type rotating electrical machine. In the axial gap type rotating electrical machine according to claim 3,
The iron core is made of a ribbon-like magnetic body wound in a spiral shape, and is an axial gap type rotating electrical machine. In the axial gap type rotating electrical machine according to claim 4,
The die-cast metal covers the back surface of the laminated surface to which the permanent magnet of the iron core is connected and the outer peripheral side surface of the iron core, and adheres to the back surface and the side surface. In the axial gap type rotating electrical machine according to any one of claims 3 to 5,
The axial gap type rotating electrical machine, wherein the die-cast metal adheres between layers of the magnetic body.   5. The axial gap type rotating electrical machine according to claim 4, wherein a groove is provided on the laminated surface of the iron core. In the axial gap type rotating electrical machine according to claim 1 or 2,
The axial gap type rotating electrical machine, wherein the iron core has a plurality of iron core portions made of a magnetic material laminated in a plurality of layers. In the axial gap type rotating electrical machine according to claim 8,
In the iron core portion, an axial gap type rotating electrical machine is characterized in that a plurality of ribbon-like magnetic bodies are laminated in a substantially fan shape. In the axial gap type rotating electrical machine according to claim 9,
The axial gap type rotating electrical machine, wherein the iron core includes structural members arranged alternately with the iron core portion. In the axial gap type rotating electrical machine according to claim 8,
In the iron core portion, a plurality of magnetic bodies are laminated in the thickness direction of the iron core portion. In any one of Claims 1 thru | or 11,
The rotor yoke has an axial gap through which the shaft passes, and an axial gap type rotating electrical machine.

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