JP2020036443A - Rotor of rotary electric machine - Google Patents

Abstract

To provide a rotor capable of improving magnetic characteristics of a rotor and a stator, efficiently flowing magnetic flux generated from a permanent magnet to the stator, and improving efficiency of a rotary electric machine.SOLUTION: A surface of a permanent magnet 14 of a rotor 1 is covered with insulating nonwoven fabric 15. A wide surface 14e facing an outer peripheral surface 10b side of a rotor core 10 and forming a magnetic pole of the permanent magnet 14, and a wide surface 14f located on the opposite side of the wide surface 14e, facing a central axis side of the rotor core 10, and forming a magnetic pole of the permanent magnet 14 are covered with wide surface covering units 15e, 15f made of nonwoven fabric containing magnetic powder 17. Both end faces 14a, 14b of the permanent magnet 14 perpendicular to a central axis of the rotor core are covered with end face coating units 15a, 15b made of nonwoven fabric containing no magnetic powder 17.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotor for a rotating electric machine, and more particularly to a rotor for an IPM (Interior Permanent Magnet) motor with a magnet embedded therein.

  BACKGROUND ART A rotor of a conventional rotating electrical machine includes a rotor core in which a plurality of circular steel plates are stacked. A rotating shaft is arranged at the center of the axis of the rotor core, and a slot is formed around the rotating shaft in the axial direction of the rotor core. A permanent magnet is arranged in the slot, and the permanent magnet is embedded in the slot by a sealing material made of epoxy resin or the like. Further, a circular end plate made of metal is fixed to both end surfaces of the rotor core (see, for example, Patent Document 1).

JP-A-2005-228775

  However, for example, in order to improve the magnetic characteristics of the rotor disclosed in Patent Document 1, it is conceivable to coat a magnetic coating on the surface of the permanent magnet in the gap between the wide surface of the plate-shaped permanent magnet and the rotor core. When a permanent magnet coated with such a magnetic coating is inserted into the slot, the magnetic coating may come into contact with the slot and peel off.

  In consideration of such a point, it is conceivable that the sealing resin may contain magnetic powder or the like, but in this case, there is a possibility that magnetic flux may be diverged also to the permanent magnet in the rotation axis direction of the rotor, and the The characteristics may be hindered on the contrary.

  The present invention has been made in view of such a problem, and improves the magnetic characteristics of the rotor and the stator, allows the magnetic flux generated from the permanent magnet to efficiently flow through the stator, and reduces the efficiency of the rotating electric machine. It is to provide a rotor that can be raised.

  In order to achieve the above object, a rotor of a rotating electric machine according to the present invention includes a rotor core having a plurality of circular steel plates stacked thereon, a rotating shaft disposed along a central axis of the rotor core, and an axial direction of the rotor core. And a plate-shaped permanent magnet buried in the slot, the rotor of the rotating electrical machine, wherein the surface of the permanent magnet is covered with non-woven fabric having an insulating property, the rotor core And a first surface on which the magnetic poles of the permanent magnet are formed, and a first surface which is located on the opposite side to the first surface and faces the center axis side of the rotor core. The second surface on which the magnetic poles are formed is covered with the nonwoven fabric containing a magnetic powder, and both end faces of the permanent magnet perpendicular to the central axis of the rotor core are formed of the non-woven fabric containing no magnetic powder. Weave Characterized in that it is covered by.

  According to the present invention, since the permanent magnet is covered with the nonwoven fabric, the insulation between the permanent magnet and the slot is maintained by the nonwoven fabric. Further, since the first and second surfaces on which the magnetic poles of the permanent magnet are formed are covered with the nonwoven fabric containing the magnetic powder, the magnetic powder can reduce the magnetic resistance to the magnetic flux from the magnetic poles of the permanent magnet. Thereby, the magnetic characteristics of the rotor can be improved, and the efficiency of the rotating electric machine can be improved.

  Further, since both end surfaces of the permanent magnet are covered with a non-woven fabric containing no magnetic powder, no magnetic flux is emitted from this portion. In addition, the expansion and contraction of the permanent magnet is reduced (buffered) by deforming the nonwoven fabric in the thickness direction, thereby suppressing cracking of the sealing material when the sealing material is disposed between the nonwoven fabric and the slot. it can. In addition, deterioration of the sealing material can be prevented.

(A) is a perspective view showing an embodiment of a rotor of a rotating electrical machine according to the present invention, and (b) is a perspective view of a permanent magnet shown in (a). 2A is a plan view of a rotor of the rotary electric machine shown in FIG. 1, FIG. 2B is an enlarged sectional view of a portion C of FIG. 1A, and FIG. 2C is an explanatory view showing magnetic poles of a permanent magnet. It is principal part sectional drawing along the AA of FIG.2 (a). It is principal part sectional drawing along the BB line of FIG.2 (a). (A) is a developed view of a permanent magnet and a nonwoven fabric covering the permanent magnet, (b) is a developed view of a modified example of the nonwoven fabric, and (c) is a perspective view of a state where the permanent magnet covered with the nonwoven fabric is inserted into a slot of the rotor. FIG. It is a development of the modification of the nonwoven fabric which covers a permanent magnet, and a permanent magnet.

Hereinafter, an embodiment of a rotor of a rotating electrical machine according to the present invention will be described in detail with reference to the drawings.
1A is a perspective view of a rotor of the rotary electric machine according to the present embodiment, FIG. 1B is a perspective view of a permanent magnet, FIG. 2A is a plan view of the rotor of the rotary electric machine shown in FIG. 2B is an enlarged sectional view of a portion C of FIG. 2A, FIG. 3C is an explanatory view showing magnetic poles of a permanent magnet, FIG. 3 is a sectional view of a main part taken along line AA of FIG. FIG. 3 is a cross-sectional view of a main part along line BB in FIG.

  A rotor 1 for an IPM motor (hereinafter, referred to as a rotor 1) shown in FIGS. 1 to 4 is a rotor of a rotating electric machine, in which a plurality of steel plates 10a, 10a... The rotor core 10 is formed by being fixed. A rotary shaft slot 11 having a circular shape in a plan view penetrates the central axis of the rotor core 10, and the rotary shaft 12 is inserted and fixed in the slot 11. Slots 13 for permanent magnets 14 are formed in the outer peripheral portion of the rotor core 10 along the axial direction of the rotating shaft 12, and permanent magnets 14 are inserted into the slots 13. Each permanent magnet 14 is covered with an insulating nonwoven fabric 15 and is embedded in the slot 13 by a sealing material 16.

  As shown in FIGS. 1 (b), 2 (b) and 2 (c), the permanent magnet 14 is formed in a plate shape that can be inserted into the slot 13, and has end faces 14a, 14b, narrow faces 14c, 14d, It has six wide surfaces 14e and 14f. In the permanent magnet 14, for example, the wide surface 14e side is magnetized to the N pole, and the wide surface 14f side is magnetized to the S pole, and the wide surfaces 14e and 14f are surfaces on which magnetic poles are formed. In the permanent magnet 14, the wide surfaces 14e and 14f are surfaces through which the magnetic flux J1 passes, and lines of magnetic force (magnetic field) J2 orbiting the wide surface 14e and the wide surface 14f are formed.

  As shown in FIGS. 2A to 2C, the wide surface 14e faces the outer peripheral surface 10b of the rotor core 10 (that is, the stator side) and is a surface on which the magnetic poles (for example, S poles) of the permanent magnets 14 are formed. And corresponds to the “first surface” in the present invention. Further, the wide surface 14f is located on the opposite side to the wide surface 14e and faces the center axis of the rotor core 10 and is the surface on which the magnetic poles of the permanent magnet 14 are formed. ". The end surfaces 14a and 14b are surfaces that are perpendicular to the central axis of the rotor core 10, and correspond to "end surfaces" in the present invention.

  In this embodiment, each slot 13 is rectangular in plan view, two adjacent slots 13 are opened in a substantially V shape in plan view, and permanent magnets 14 are inserted to form one magnetic field. are doing. In the rotor core 10, 16 permanent magnets 14, 14... Are inserted into 16 slots 13, 13... In total, so that a total of eight magnetic poles are formed on the outer peripheral portion of the rotor core 10. Each of the permanent magnets 14 is formed in a slightly small size with respect to each of the slots 13, and has a shape that allows easy insertion.

  Specifically, as shown in FIG. 3 and FIG. 4, the permanent magnet 14 is formed in a vertical width L1, a horizontal width W1, and a height H1, and the slot 13 is formed in a vertical L2, a horizontal W2, and a height H2. The length L1 and the width W1 of the permanent magnet 14 are larger than the height H1. For this reason, a gap of (L2-L1) is formed between the slot 13 and the permanent magnet 14 in the vertical direction, a gap of (W2-W1) is formed in the horizontal direction, and a gap of (W2-W1) is formed in the height direction. A gap of H2-H1) is formed.

  The surface of the permanent magnet 14 is covered with a nonwoven fabric 15 having an insulating property, and the nonwoven fabric 15 is disposed in a vertical gap, a horizontal gap, and a height gap. In this arrangement, the nonwoven fabric 15 is elastically deformable in the thickness direction. Examples of the material of the nonwoven fabric 15 include a resin having an insulating property.

  More specifically, the permanent magnet 14 has a rectangular cross section along the axial direction, and is formed in a vertically long rectangular parallelepiped as a whole. As shown in FIG. It is formed so as to cover six surfaces of the rectangular parallelepiped. That is, the nonwoven fabric 15 has the end surface covering portions 15a and 15b, the narrow surface covering portions 15c and 15d, and the wide surface covering portions 15e and 15f, which are formed as one sheet.

  The insulating nonwoven fabric 15 covers the six outer surfaces of the permanent magnet 14. The wide surfaces 14e and 14f, which are the surfaces on which the magnetic poles of the permanent magnet 14 are formed, are covered with wide surface covering portions 15e and 15f made of a nonwoven fabric containing a magnetic powder 17.

  On the other hand, the end surfaces 14a and 14b of the permanent magnet 14 are covered with end surface coating portions 15a and 15b made of a nonwoven fabric that does not contain the magnetic powder 17. Further, the narrow surfaces 14c and 14d of the permanent magnet 14 are covered with narrow surface covering portions 15c and 15d, and the narrow surface covering portions 15c and 15d are made of a nonwoven fabric that does not contain the magnetic powder 17. However, as shown in FIG. 5B, the narrow surface covering portions 15c and 15d may be made of a nonwoven fabric that does not contain the magnetic powder 17.

  The magnetic powder 17 may be a magnetic material, and examples thereof include metal powder such as iron powder, and it is preferable that an insulating film is formed on the surface thereof. Examples of the insulating film include a resin such as silicone, and a material such as metal nitride or metal oxide.

The shape of the magnetic powder 17 is not particularly limited, but the average particle size is preferably, for example, 30 to 100 μm. Further, the content density of the magnetic powder 17 is preferably, for example, 0.06 to 3 g / cm ² . In order to include the magnetic powder 17 in a predetermined portion of the nonwoven fabric 15, the magnetic powder 17 may be arranged in a space within the thickness of the nonwoven fabric 15 and fixed with, for example, an adhesive. Further, an adhesive containing the magnetic powder 17 may be applied to the surface of the nonwoven fabric 15.

  The permanent magnet 14 whose surface is covered with the nonwoven fabric 15 in this way is inserted into the slot 13 penetrating in the axial direction of the rotor core 10, as shown in FIG. As described above, since the height of the permanent magnet 14 is smaller than the height of the slot 13, when the permanent magnet 14 is inserted into the slot 13, a space is formed on both sides in the axial direction. The sealing material 16 is injected into this space, and the permanent magnet 14 is embedded in the slot 13.

  When the rotor core 10 is used as a rotating electric machine, the outer peripheral surface 10b of the rotor core 10 is a cylindrical surface that is close to and opposed to a stator (not shown). The wide surface covering portions 15e and 15f containing the magnetic powder 17 form the magnetic poles of the N pole and the S pole, so that the magnetic flux emitted from the permanent magnet 14 passes through the magnetic powder 17 efficiently and forms a magnetic field reaching the stator. can do.

  A sealing material 16 is arranged between the nonwoven fabric 15 and the slot 13. That is, the gap between the slot 13 and the permanent magnet 14 is filled with the sealing material 16, and the permanent magnet 14 covered with the nonwoven fabric 15 is embedded and fixed in the slot 13 with the sealing material 16. As the sealing material 16, for example, epoxy resin is used, and each permanent magnet 14 is fixed in the slot 13 by the sealing material 16. In addition, the sealing material 16 is not limited to an epoxy resin, and another resin may be used.

  When filling and filling the gap between the slot 13 and the permanent magnet 14 with the sealing material 16, it is preferable that the thickness of the sealing material 16 be uniform around the permanent magnet 14. Specifically, in FIG. 3, the permanent magnet 14 is positioned so that the center of the longitudinal dimension L1 of the permanent magnet 14 coincides with the center of the longitudinal dimension L2 of the slot 13, and the height dimension H2 of the slot 13 The sealing material 16 is filled so that the center of the height H1 of the permanent magnet 14 is aligned with the center. In this case, the thickness H3 of the sealing material 16 below the permanent magnet 14 is equal to the thickness H4 of the sealing material 16 above the permanent magnet 14.

  In FIG. 4, the sealing material 16 is filled so that the center of the lateral dimension W2 of the slot 13 is aligned with the center of the lateral dimension W1 of the permanent magnet 14. At least the sealing material 16 is arranged so as to seal the permanent magnet 14 from the openings on both sides of the slot 13 (from the end face side of the permanent magnet 14). Since the nonwoven fabric 15 is not impregnated with the sealing material 16, the nonwoven fabric 15 can be elastically deformed in the thickness direction in this arrangement state. In this manner, the permanent magnet 14 is positioned at the center position of the internal space of the slot 13, and the gap between the slot 13 and the permanent magnet 14 covered with the nonwoven fabric 15 is injected and filled with the sealing material 16. The thickness in the vertical direction, the thickness in the horizontal direction, and the thickness in the height direction of the sealing material 16 can be made uniform.

  As the permanent magnet 14, a magnet containing a rare earth metal is used. As the rare earth magnet, it is preferable to use a permanent magnet such as a neodymium magnet and a samarium cobalt magnet. The permanent magnet 14 is not limited to a magnet containing a rare earth metal, but may be a suitable magnet such as a ferrite magnet or an alnico magnet.

  A method of manufacturing the rotor 1 of the rotating electric machine of the present embodiment configured as described above and its operation will be described below. As described above, the rotor core 10 in which the plurality of circular steel plates 10a, 10a,... Is stacked is prepared, and the rotary shaft 12 is disposed in the slot 11 formed through the center of the rotor core 10 in the axial direction. Next, a plurality of permanent magnets 14, 14... Are inserted and embedded in the plurality of slots 13, 13.

  When the permanent magnet 14 is inserted into the slot 13, the plate-shaped permanent magnet 14 is inserted into the slot 13 along the longitudinal direction in a state where the six surfaces of the permanent magnet 14 are covered with the nonwoven fabric 15. In addition, as shown in FIG. 5A or 5B, the nonwoven fabric 15 contains the magnetic powder 17 in the above-described portions.

  Thereafter, a sealing material 16 is injected and filled into the slots 13 around the nonwoven fabric 15 covering the permanent magnets 14. Thereby, the sealing material 16 is arranged between the nonwoven fabric 15 and the slot 13, and the permanent magnet 14 covered with the nonwoven fabric 15 is fixed in the slot 13 by the sealing material 16. Since the sealing material 16 made of an epoxy resin or the like is not completely impregnated and air is contained in the nonwoven fabric 15, the nonwoven fabric 15 can be compressed and deformed in the thickness direction.

  In the rotor 1 of the rotating electric machine of the present embodiment configured as described above, the permanent magnets 14 inserted and embedded in the slots 13 of the rotor core 10 are covered with a nonwoven fabric 15 having an insulating property. Therefore, insulation between the permanent magnet 14 and the rotor core 10 is maintained.

  In the nonwoven fabric 15, at least the wide surfaces 14e and 14f on which the magnetic poles of the permanent magnet 14 are formed are covered with wide surface covering portions 15e and 15f made of a nonwoven fabric containing a magnetic powder 17, and the magnetic powder 17 is insulated. Since the permanent magnet 14 and the rotor core 10 are covered with the conductive film, the insulation between the permanent magnet 14 and the rotor core 10 is maintained.

  Further, the wide surface covering portions 15e and 15f of the nonwoven fabric 15 covering the wide surfaces 14e and 14f, which are the surfaces on which the magnetic poles of the permanent magnet 14 are formed, contain the magnetic powder 17, so that the magnetic flux emitted from the permanent magnet 14 J1 is transmitted through the magnetic powder 17, and the attenuation of the magnetic flux due to the gap can be prevented, and the deterioration of the magnetic characteristics is prevented. Therefore, when the rotor core 10 is used as a rotating electric machine, a decrease in the efficiency of the rotating electric machine is prevented.

  Next, another embodiment of the nonwoven fabric will be described with reference to FIG. The nonwoven fabric shown in FIG. 6 has a two-part configuration. One nonwoven fabric 35A uniformly contains the magnetic powder 17. The nonwoven fabric 35A has narrow surface covering portions 35c and 35d and wide surface covering portions 35e and 35f, which are connected as one sheet. Further, the other nonwoven fabric 35B does not contain the magnetic powder 17, and has end face covering portions 35a, 35b and narrow surface covering portions 35g, 35h, which are connected as one sheet.

  In this embodiment, the nonwoven fabric 35A and the nonwoven fabric 35B are wound around the permanent magnet 14 to cover the outer six surfaces. Thereby, the narrow surface covering portion 35d (35c) of the nonwoven fabric 35A and the narrow surface covering portion 35g (35h) of the nonwoven fabric 35B overlap.

  The wide surface covering portions 35e and 35f of the nonwoven fabric 35A that cover the wide surfaces 14e and 14f on which the magnetic poles of the permanent magnet 14 are formed contain the magnetic powder 17. As a result, the magnetic resistance of the permanent magnet 14 is reduced, and the lines of magnetic force do not weaken, so that the rotating electric machine can be rotated with high efficiency. On the other hand, since the end surface covering portions 35a and 35b that cover the end surfaces 14a and 14b of the permanent magnet 14 do not contain magnetic powder, the end surface covering portions 35a and 35b can function as a cushioning material.

  As described above, one embodiment of the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention described in the appended claims. Design changes can be made.

1: Rotor of rotating electric machine, 10: Rotor core, 10a: Steel plate, 11: Slot for rotating shaft, 12: Rotating shaft, 13: Slot for permanent magnet, 14: Permanent magnet, 14a, 14b: End face, 14e: Wide face (First surface), 14f: wide surface (second surface), 15, 15A: insulating nonwoven fabric, 15e, 15f: wide surface coating portion (nonwoven fabric containing magnetic powder), 15a, 15b: end surface coating portion (Non-woven fabric containing no magnetic powder), 16: encapsulating material, 17: magnetic powder, 35A, 35B: insulating non-woven fabric, 35a, 35b: end surface coating portion (non-woven fabric containing no magnetic powder)

Claims (1)

A rotor core in which a plurality of circular steel plates are stacked, a rotating shaft disposed along a central axis of the rotor core, a slot penetrating in an axial direction of the rotor core, and a plate-shaped permanent magnet embedded in the slot And a rotor of a rotating electric machine comprising:
The surface of the permanent magnet is covered with an insulating nonwoven fabric,
A first surface on which the magnetic poles of the permanent magnet are formed, and a first surface facing the outer peripheral surface side of the rotor core, and which is located on a side opposite to the first surface and faces the center axis side of the rotor core; The second surface on which the magnetic poles of the magnet are formed is covered with the nonwoven fabric containing magnetic powder,
A rotor for a rotating electric machine, wherein both end faces of the permanent magnet perpendicular to the central axis of the rotor core are covered with the nonwoven fabric containing no magnetic powder.

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