JP2015142484A - Surface magnet type rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure in which a permanent magnet can be inexpensively fixed in a simple method without reduction in performance and increase in the number of man-hours in a surface magnet type rotary electric machine.SOLUTION: Disclosed is a surface magnet type rotary electric machine comprising: a rotor 1 on which a rotor magnet 3 composed of a plurality of permanent magnets 30 is mounted; and a stator having a coil wound therearound. This rotary electric machine includes a notch 31 provided at the end of the permanent magnet 30 and a ring member 4 for magnet fixation formed in size corresponding to this notch 31. The ring member 4 is fitted to the notch 31 and the permanent magnet 30 is fixed to the rotor 1.

Description

  The present invention relates to a structure for fixing a permanent magnet in a surface magnet type rotary electric machine, that is, a surface magnet type rotary electric motor or a surface magnet type generator.

  A permanent magnet type rotating electrical machine that is an electric motor or a generator using a permanent magnet includes a surface magnet type (SPM) in which a magnet is arranged on a rotor or stator surface, and an embedded magnet type (IPM) in which the magnet is incorporated in an iron core of a rotor. It is roughly divided into

  In this type of permanent magnet type rotating electrical machine, in the case of the embedded magnet type, a pocket for inserting a magnet is formed in the iron core of the rotor, and the magnet can be easily arranged by inserting the magnet into this pocket. It can be fixed, and there is no risk of magnet scattering or the like when the rotor rotates.

  On the other hand, the surface magnet type has a structure in which a magnet is attached to the surface of the rotor or the stator. Therefore, particularly when rotated as an inner rotor, there is a concern about scattering, peeling, breakage, etc. of the magnet due to centrifugal force. Furthermore, when the magnet arrangement is fixed while receiving a strong repulsive force like the Halbach type arrangement, it is necessary to consider more robustness.

  A method of fixing a surface magnet type permanent magnet is disclosed in Patent Document 1. In Patent Document 1, after the rotor magnet is fixed to the shaft, the entire surface of the magnet outer diameter portion is covered with a circular carbon ring to prevent scattering of the magnet. In addition, a wedge-shaped metal fitting is inserted between adjacent magnets to further improve the fixing strength.

  Moreover, in patent document 2, the slit which inserts a magnet previously in the rotor core outer diameter side was provided, and after arrange | positioning the magnet part, the method of deform | transforming and pressing the magnet was taken.

JP 2005-312250 A Japanese Patent Laid-Open No. 2004-23944

  As described above, in order to prevent scattering, peeling, breakage, and the like of the magnet in the surface magnet type, a structure in which the magnet is mechanically pressed using the magnet outer diameter side or between adjacent magnets is effective. However, in the structure in which the ring member is provided on the outer diameter part of the rotor magnet as in Patent Document 1, it is necessary to increase the distance (motor gap) from the magnet (field) surface to the armature coil by the thickness of the ring member. This leads to a decrease in motor output and motor efficiency.

  Also, in the structure in which the portion between the magnets is pressed by a wedge-shaped member, the volume of the wedge member and the volume of the magnet are reduced compared to the configuration in which the magnets are spread without gaps. The efficiency will be reduced.

  Further, in Patent Document 2, a method of deforming the core is taken, but usually, a laminated steel plate or a dust core is used for the rotor core (iron core). The laminated portion is peeled off or the magnetic characteristics are deteriorated due to residual stress. In the case of a dust core, deformation is almost impossible and the possibility of crushing is high. On the other hand, if a solid material is used without using a laminated steel plate or a dust core, the iron loss during rotation increases and the performance is lowered. In addition, these means have a shape in which a magnetic body wraps around the side surface of the rotor magnet, and there are concerns about the influence on the field magnetic flux.

  Accordingly, an object of the present invention is to provide a structure that can fix a permanent magnet by an inexpensive and simple method in a surface magnet type rotating electric machine without causing a decrease in performance or an increase in man-hours.

  In order to solve the above-described problems, the present invention provides a surface magnet type rotary electric machine including a rotor having a rotor magnet composed of a plurality of permanent magnets and a stator wound with a coil. A notch portion provided and a magnet fixing ring member formed in a size corresponding to the notch portion, the ring member being fitted into the notch portion, and a permanent magnet being fixed to the rotor It is characterized by.

  The rotor is an inner rotor in which a plurality of permanent magnets are attached to the outer periphery of a rotor core, and can be configured to have cutout portions provided at both end portions in the axial direction of the permanent magnet.

  The rotor is an outer rotor in which a plurality of permanent magnets are attached to the inner periphery of a back yoke or a casing member, and is configured to be provided with notches at both ends on the inner periphery side in the axial direction of the permanent magnet. be able to.

  Further, the rotor is an axial gap type rotor, a plurality of permanent magnets are arranged in a disk shape on a disk-shaped back yoke, and notches are formed at the outer peripheral side and inner peripheral side ends of each permanent magnet. It can comprise so that it may provide.

  Further, the cutout portion of the magnet may be formed in a rectangular shape, a tapered shape, or an arc shape in cross section.

  Further, a Halbach array can be applied to the rotor magnetic poles.

  The magnet fixing ring member may be formed of a non-magnetic material.

  As described above, according to the present invention, the structure in which the magnet is fixed at the end portion in the axial direction of the magnet substantially eliminates the performance degradation and the increase in the number of man-hours, and can make the surface magnet type rotating electrical machine a robust structure. .

It is a disassembled perspective view which shows the rotor of the surface magnet type inner rotor type electric motor which shows 1st Embodiment of this invention. 1 is a schematic cross-sectional view showing a surface magnet type inner rotor type electric motor showing a first embodiment of the present invention. It is a schematic diagram which shows the magnet arrangement | sequence of a rotor magnet, (a) is a normal magnet arrangement | sequence, (b) is a Halbach type | mold arrangement | sequence. It is a schematic diagram which shows the direction which the magnet in a Halbach type | mold arrangement | sequence tries to shift | deviate. It is a disassembled perspective view which shows the rotor of the surface magnet type outer rotor type | mold electric motor which shows 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the surface magnet type outer rotor type | mold electric motor which shows 2nd Embodiment of this invention. It is a disassembled perspective view which shows the rotor of the axial gap type surface magnet type motor which shows 3rd Embodiment of this invention. It is a schematic sectional drawing which shows the axial gap type surface magnet type motor which shows 3rd Embodiment of this invention. It is a schematic diagram which shows the fitting aspect of a rotor magnet and the ring member for magnet fixation, (a) is a surface magnet type inner rotor type electric motor, (b) is a surface magnet type outer rotor type electric motor or an axial gap type surface magnet type An electric motor is shown. It is a schematic diagram which shows other embodiment of the fitting aspect of a rotor magnet and a ring member for magnet fixation, (a) is a surface magnet type inner rotor type electric motor, (b) is a surface magnet type outer rotor type electric motor or an axial. A gap type surface magnet type electric motor is shown. It is a schematic diagram which shows other embodiment of the fitting aspect of a rotor magnet and a ring member for magnet fixation, (a) is a surface magnet type | mold inner rotor type | mold electric motor, (b) is a surface magnet type | mold outer rotor type | mold motor or An axial gap type surface magnet type electric motor is shown.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the first embodiment, the present invention is applied to a surface magnet type inner rotor type electric motor which is an example of a surface magnet type rotating electrical machine. FIG. 1 is an exploded perspective view showing a rotor of a surface magnet type inner rotor type electric motor showing a first embodiment of the present invention, and FIG. 2 is a surface magnet type inner rotor type electric motor showing a first embodiment of the present invention. It is a schematic sectional drawing which shows.

  As shown in FIGS. 1 and 2, the rotor 1 is provided with a rotor core 2 a on a shaft 2. The rotor core 2 a is larger in diameter than the shaft 2. A rotor magnet 3 is disposed on the outer periphery of the rotor core 2a.

  Each permanent magnet 30 of the rotor magnet 3 is provided with a notch 31 on the outer diameter side of both end portions in the axial direction. In this embodiment, a notch 31 having a rectangular cross section is provided.

  When all the permanent magnets 30 are fixed to the outer periphery of the rotor core 2 a and the rotor magnet 3 is arranged, notches 31 are provided at both ends of the rotor magnet 3. The magnet fixing ring member 4 formed in a size corresponding to the notch 31 is fitted into the rotor magnet 3 to be fixed. In this embodiment, the ring member 4 having a rectangular cross-sectional shape is used, and when the ring member 4 is fitted into the notch 31, the rotor magnet 3 is integrated with no step difference. The ring member 4 is made of, for example, a nonmagnetic material. In addition, you may form the ring member 4 with a magnetic body.

  The rotor magnet 3 is fixed to the rotor 1 by temporarily fixing all the permanent magnets 30 around the rotor core 2a with an adhesive, and then fixing ring members for fixing magnets to the notches 31 at both ends of the rotor magnet 3. This is done by fitting 4.

  A stator 5 having a motor gap on the outer periphery of the rotor 1 and having a coil 5b wound around a stator core 5a is arranged to constitute a surface magnet type inner rotor type electric motor.

  By adopting such a structure, it is possible to easily prevent the permanent magnet 30 from being scattered, peeled off, damaged or the like due to centrifugal force or magnetic acting force during rotation. In addition, with this shape, nothing is inserted between the motor gap part and the permanent magnets 30 and 30, so that there is almost no deterioration in performance due to an increase in the motor gap or a decrease in the magnet volume. Furthermore, as compared with a method of fixing the wedge-shaped member between the permanent magnets 30 and 30 by screwing or deforming and fixing the member, it is only necessary to fit the ring member 4 into the notch 31, Cost is also very small.

  FIG. 3 shows the magnet arrangement of the rotor magnet 3. The magnet arrangement may be a Halbach type arrangement shown in (b) other than the normal magnet arrangement shown in FIG. In FIG. 3, the hatching around the magnet indicates the magnetic field area. In the normal magnet arrangement shown in FIG. 3A, the permanent magnets 30a are magnetized in the radial direction, and these are arranged so that the S poles and the N poles are alternated. On the other hand, in the Halbach array, the permanent magnet 30a is radially magnetized and the permanent magnet 30b is circumferentially magnetized.

  As shown in FIG. 3B, this Halbach type arrangement can generate a strong magnetic field only on one side with respect to the arrangement direction of the magnets, and also has a feature that the magnetic poles are switched in a sine wave form. Yes. Compared with the normal magnet arrangement in which N poles and S poles are alternately arranged as shown in FIG. 3A, it is possible to generate a strong magnetic field farther away.

  However, on the other hand, in this arrangement, the magnets receive a strong repulsive force against each other, and a force that always moves in the direction of the arrow shown in FIG. Therefore, it is necessary to firmly fix the magnet, and when using it for the surface magnet type, it must be conscious of prevention of scattering, peeling, breakage, etc. of the magnet, but the magnet fixing method of the present invention is simple and easy. In addition, a robust structure can be achieved at low cost.

  In the second embodiment, the present invention is applied to a surface magnet type outer rotor type electric motor which is an example of a surface magnet type rotating electrical machine. As shown in FIGS. 5 and 6, in the rotor 1, the rotor magnet 3 is disposed on the inner periphery of a cylindrical back yoke 1b. A casing member may be used instead of the back yoke 1b.

  Each permanent magnet 30 of the rotor magnet 3 is provided with a notch 31 on the inner peripheral side of both end portions in the axial direction. In this embodiment, a notch 31 having a rectangular cross section is provided.

  When all the permanent magnets 30 are fixed to the inner periphery of the back yoke 10 and the rotor magnet 3 is disposed, notches 31 are provided at both ends on the inner periphery side of the rotor magnet 3. The magnet fixing ring member 4 formed in a size corresponding to the notch 31 is fitted into the rotor magnet 3 to be fixed. In this embodiment, the ring member 4 having a rectangular cross-sectional shape is used, and when the ring member 4 is fitted into the notch 31, the rotor magnet 3 is integrated with no step difference.

  The rotor magnet 3 is fixed to the rotor 1 by temporarily fixing all the permanent magnets 30 to the inner periphery of the back yoke 10 with an adhesive, and then fixing the magnets to the notches 31 at both ends of the rotor magnet 3. This is done by fitting the ring member 4.

  The stator 5 having a motor gap on the inner periphery of the rotor 1 and having the coil 5b wound around the stator core 5a is arranged to constitute a surface magnet type outer rotor type electric motor.

  By the way, in the case of an outer rotor type electric motor, even if a centrifugal force is applied, it is mechanically suppressed by the back yoke 1b (or casing member) on the outer peripheral portion of the rotor magnet 3, so that robustness is relatively easily secured. However, in the case of using the Halbach array, as described above, there is a possibility that the magnets are peeled off due to the strong repulsive force of each other, so the fixing method of the present invention is effective.

  In the first and second embodiments described above, the radial gap type motor has been described. However, the present invention can be similarly applied to an axial gap type motor as shown in FIGS.

  In the axial gap type electric motor according to the third embodiment of the present invention, the rotor magnet 3 is arranged in a disc shape on a disc-like back yoke 11. Notch portions 31 are provided at the outer peripheral side and inner peripheral side ends of each permanent magnet 30 of the rotor magnet 3. The magnet fixing ring member 4 having a size corresponding to the notch 31 is fitted into the notch 31 of the rotor magnet 3 to constitute the rotor 1. A casing member may be used instead of the back yoke 11. A shaft is attached to the back yoke 10 or the casing member, and the rotor 1 is configured.

  The rotor magnet 3 of the disk-shaped back yoke 11 is fixed. After all the permanent magnets 30 are temporarily fixed to the surface of the back yoke 11 using an adhesive, the magnet fixing ring member 4 is fitted into the notch 31.

  Then, a stator 5 having a predetermined motor gap in the axial direction of the rotor 1 and having a coil 5b wound around the stator core 5a is arranged to constitute a surface magnet type outer rotor type electric motor.

  Further, in each of the above-described embodiments, as shown in FIGS. 9 (a) and 9 (b), the magnet fixing ring member 4 has a rectangular cross-sectional shape as an example, but FIGS. 10 (a) and 10 (b). The ring member 4 having an L-shaped cross section as shown in FIG.

  Further, as shown in FIGS. 11A and 11B, the shape of the notch may be a groove-like notch 31a that does not open in either the inner or outer diameter direction or the axial direction of the magnet.

  In each of the above-described embodiments, the cutout portions 31 and 31a are formed in a rectangular cross section. However, the cutout portions 31 and 31a are not limited to a rectangular cross section, and are formed in a tapered shape or an arc shape. You can also. In this case, the cross-sectional shape of the ring member 4 may correspond to the cross-sectional shape of the notches 31 and 31a.

  In the above-described embodiment, an example in which the present invention is applied to an electric motor has been described. However, the present invention can be similarly applied to a generator that is another rotating electric machine.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims for patent.

DESCRIPTION OF SYMBOLS 1 Rotor 1b Back yoke 2 Shaft 2a Rotor core 3 Rotor magnet 4 Ring member 5 Stator 5a Stator core 5b Coil 30 Permanent magnets 31 and 31a Notch

Claims (6)

In a surface magnet type rotating electrical machine composed of a rotor having a rotor magnet composed of a plurality of permanent magnets and a stator wound with a coil,
A notch provided at an end of the permanent magnet, and a magnet fixing ring member formed in a size corresponding to the notch, the ring member being fitted into the notch, and a rotor A surface magnet type rotating electric machine characterized in that a permanent magnet is fixed to the surface.   2. The surface according to claim 1, wherein the rotor is an inner rotor in which a plurality of permanent magnets are attached to an outer periphery of a rotor core, and notches are provided at both ends of the permanent magnet in the axial direction. Magnet type rotating electrical machine.   The rotor is an outer rotor in which a plurality of permanent magnets are attached to the inner periphery of a back yoke or a housing member, and notches are provided at both ends on the inner periphery side in the axial direction of the permanent magnet. The surface magnet type rotating electric machine according to claim 1.   The rotor is an axial gap type rotor, in which a plurality of permanent magnets are arranged in a disk shape on a disk-shaped back yoke, and notches are formed at the outer peripheral side and inner peripheral side ends of each permanent magnet. The surface magnet type rotating electric machine according to claim 1, wherein the surface magnet type rotating electric machine is provided.   5. The surface magnet type rotating electric machine according to claim 1, wherein the cutout portion of the magnet has a cross-sectional shape that is rectangular, tapered, or arcuate. . The surface magnet type rotating electric machine according to any one of claims 1 to 5, wherein a Halbach type arrangement is applied to the rotor magnetic pole.

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